DNA: DNA, short for deoxyribonucleic acid, is the molecule that contains the genetic code of living organisms. This includes animals, plants, protists, archaea and bacteria. It is made up of two polynucleotide chains in a double helix.
DNA is in each cell in the organism and tells cells what proteins to make. Mostly, these proteins are enzymes. DNA is inherited by children from their parents. This is why children share traits with their parents, such as skin, hair and eye color. The DNA in a person is a combination of the DNA from each of their parents.
Part of an organism's DNA is "non-coding DNA" sequences. They do not code for protein sequences. Some noncoding DNA is transcribed into non-coding RNA molecules, such as transfer RNA, ribosomal RNA, and regulatory RNAs. Other sequences are not transcribed at all, or give rise to RNA of unknown function. The amount of non-coding DNA varies greatly among species. For example, over 98% of the human genome is non-coding DNA, while only about 2% of a typical bacterial genome is non-coding DNA.
Viruses use either DNA or RNA to infect organisms. The genome replication of most DNA viruses takes place in the cell's nucleus, whereas RNA viruses usually replicate in the cytoplasm.
Inside eukaryotic cells, DNA is organized into chromosomes. Before cell division, more chromosomes are made in the process of DNA replication. Eukaryotic organisms like animals, plants, fungi and protists store most of their DNA inside the cell nucleus. But prokaryotes, like bacteria and archaea store their DNA only in the cytoplasm, in circular chromosomes. Inside eukaryotic chromosomes, chromatin proteins, such as histones, help to compact and organize DNA.
 Structure of DNA 
DNA has a double helix shape, which is like a ladder twisted into a spiral. Each step of the ladder is a pair of nucleotides.
 Nucleotides 
A nucleotide is a molecule made up of:
deoxyribose, a kind of sugar with five carbon atoms,
a phosphate group made of phosphorus and oxygen, and
nitrogenous base
DNA is made of four types of nucleotide:
 Adenine (A)
 Thymine (T)
 Cytosine (C)
 Guanine (G)
The 'rungs' of the DNA ladder are each made of two bases, one base coming from each leg. The bases connect in the middle: 'A' only pairs with 'T', and 'C' only pairs with 'G'. The bases are held together by hydrogen bonds.
Adenine (A) and thymine (T) can pair up because they make two hydrogen bonds, and cytosine (C) and guanine (G) pair up to make three hydrogen bonds. Although the bases are always in fixed pairs, the pairs can come in any order (A-T or T-A; similarly, C-G or G-C). This way, DNA can write 'codes' out of the 'letters' that are the bases. These codes contain the message that tells the cell what to do.
 Chromatin 
On chromosomes, the DNA is bound up with proteins called histones to form chromatin. This association takes part in epigenetics and gene regulation. Genes are switched on and off during development and cell activity, and this regulation is the basis of most of the activity which takes place in cells.
 Copying DNA 
When DNA is copied, this is called DNA replication. Briefly, the hydrogen bonds holding together paired bases are broken and the molecule is split in half: the legs of the ladder are separated. This gives two single strands. New strands are formed by matching the bases (A with T and G with C) to make the missing strands.
First, an enzyme called DNA helicase splits the DNA down the middle by breaking the hydrogen bonds. Then after the DNA molecule is in two separate pieces, another molecule called DNA polymerase makes a new strand that matches each of the strands of the split DNA molecule. Each copy of a DNA molecule is made of half of the original (starting) molecule and half of new bases.
 Mutations 
When DNA is copied, mistakes are sometimes made – these are called mutations. There are four main types of mutations:
 Deletion, where one or more bases are left out.
 Substitution, where one or more bases are substituted for another base in the sequence.
 Insertion, where one or more extra base is put in.
 Duplication, where a sequence of bases pairs are repeated.
Mutations may also be classified by their effect on the structure and function of proteins, or their effect on fitness. Mutations may be bad for the organism, or neutral, or of benefit. Sometimes mutations are fatal for the organism – the protein made by the new DNA does not work at all, and this causes the embryo to die. On the other hand, evolution is moved forward by mutations, when the new version of the protein works better for the organism.
 Protein synthesis 
A section of DNA that contains instructions to make a protein is called a gene. Each gene has the sequence for at least one polypeptide. Proteins form structures, and also form enzymes. The enzymes do most of the work in cells. Proteins are made out of smaller polypeptides, which are formed of amino acids. To make a protein to do a particular job, the correct amino acids need to be joined up in the correct order.
Proteins are made by tiny machines in the cell called ribosomes. Ribosomes are in the main body of the cell, but DNA is only in the nucleus of the cell. The codon is part of the DNA, but DNA never leaves the nucleus. Because DNA cannot leave the nucleus, the cell nucleus makes a copy of the DNA sequence in RNA. This is smaller and can get through the holes – pores – in the membrane of the nucleus and out into the cell.
Genes encoded in DNA are transcribed into messenger RNA (mRNA) by proteins such as RNA polymerase. Mature mRNA is then used as a template for protein synthesis by the ribosome. Ribosomes read codons, 'words' made of three base pairs that tell the ribosome which amino acid to add. The ribosome scans along an mRNA, reading the code while it makes protein. Another RNA called tRNA helps match the right amino acid to each codon.
 History of DNA research 
DNA was first isolated (extracted from cells) by Swiss physician Friedrich Miescher in 1869, when he was working on bacteria from the pus in surgical bandages. The molecule was found in the nucleus of the cells and so he called it nuclein.
In 1928, Frederick Griffith discovered that traits of the "smooth" form of Pneumococcus could be transferred to the "rough" form of the same bacteria by mixing killed "smooth" bacteria with the live "rough" form. This system provided the first clear suggestion that DNA carries genetic information.
The Avery–MacLeod–McCarty experiment identified DNA as the transforming principle in 1943.
DNA's role in heredity was confirmed in 1952, when Alfred Hershey and Martha Chase in the Hershey–Chase experiment showed that DNA is the genetic material of the T2 bacteriophage.
In the 1950s, Erwin Chargaff found that the amount of thymine (T) present in a molecule of DNA was about equal to the amount of adenine (A) present. He found that the same applies to guanine (G) and cytosine (C). Chargaff's rules summarises this finding.
In 1953, James D. Watson and Francis Crick suggested what is now accepted as the first correct double-helix model of DNA structure in the journal Nature. Their double-helix, molecular model of DNA was then based on a single X-ray diffraction image "Photo 51", taken by Rosalind Franklin and Raymond Gosling in May 1952.
Experimental evidence supporting the Watson and Crick model was published in a series of five articles in the same issue of Nature. Of these, Franklin and Gosling's paper was the first publication of their own X-ray diffraction data and original analysis method that partly supported the Watson and Crick model; this issue also contained an article on DNA structure by Maurice Wilkins and two of his colleagues, whose analysis and in vivo B-DNA X-ray patterns also supported the presence in vivo of the double-helical DNA configurations as proposed by Crick and Watson for their double-helix molecular model of DNA in the previous two pages of Nature. In 1962, after Franklin's death, Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine. Nobel Prizes are awarded only to living recipients. A debate continues about who should receive credit for the discovery.
In 1957, Crick explained the relationship between DNA, RNA, and proteins, in the central dogma of molecular biology.
How DNA was copied (the replication mechanism) came in 1958 through the Meselson–Stahl experiment. More work by Crick and coworkers showed that the genetic code was based on non-overlapping triplets of bases, called codons. These findings represent the birth of molecular biology.
How Watson and Crick got Franklin's results has been much debated. Crick, Watson and Maurice Wilkins were awarded the Nobel Prize in 1962 for their work on DNA – Rosalind Franklin had died in 1958.
 What happens when DNA gets damaged 
DNA gets damaged a lot of times in cells which is a problem has DNA provide instructions to making proteins. But, cells have ways to fix these problems most of the time. Cells make use of special enzymes. Different enzymes fix different types of damages to DNA. The problem comes in different types:
 One common error is base mismatch or where the bases are not matched correctly. This is where maybe for example, adenine is not matched with thymine or Guanine is not matched with cytosine. When a cell copies its own DNA a special enzyme called polymerase matches the bases together. But once in a while, there is an error. Usually, the enzyme notices it and fixes it, but just make sure, another set of proteins check what the enzyme has done. If the proteins find a base that was not matched with the right base, they remove it and replace it with a nucleotide with the right base.
 DNA can also be broken chemically by certain compounds. This can be toxic compounds like those found in tobacco or compounds the cell meets every day like hydrogen peroxide. Some chemical damages by compounds happens so much that there is a special enzyme to fix those types of problems.
 When a Nitrogenous base gets damaged, it is usually fixed in a process called base excision repair. Here, an enzyme removes the base and another group of enzymes trim around the damage and replaces it with a new nucleotide.
 UV light damages DNA in such a way that it changes its shape. Fixing this type of damage takes a more complex process called nucleotide excision repair. Here, a team of proteins remove a long strand of 20 or more broken nucleotides and replaces them with fresh new ones.
 High energy waves like x-rays and gamma rays can actually cut one or both strands of DNA. This type of damage is called a double strand break. One double strand break can cause the cell to die. Two common ways the cell fixes this problem is homologous recombination and non homologous end joining. In homologous recombination, enzymes use a similar part of another gene as a template to fix the break. In non-homologous end joining enzymes trim around the place where the DNA strand broke and put them together. This way is much less accurate but works when there is no similar genes available.
DNA and privacy concerns
Police in the United States used DNA and family tree public databases to solve cold cases. The American Civil Liberties Union raised concerns over this practice.


Water: water in its solid state Ice
water in its gas state Water vapor
477162647 Water () H2O 2D labelled.svg 150px The water molecule has this basic geometric structure Water-3D-balls.png 100px Ball-and-stick model of a water molecule Water molecule 3D.svg 100px Space filling model of a water molecule 2006-02-13 Drop before impact.jpg 264px A drop of water falling towards water in a glass water, oxidane Hydrogen hydroxide (HH or HOH), hydrogen oxide, dihydrogen monoxide (DHMO) (systematic name), hydrogen monoxide, dihydrogen oxide, hydric acid, hydrohydroxic acid, hydroxic acid, hydrol, μ-oxido dihydrogen, κ1-hydroxyl hydrogen(0) Water (data page) 
Water (H 2 O) is a simple chemical compound made of two hydrogen atoms and one oxygen atom. It is clear, has no taste or smell, and is almost colorless. All living things need water to survive. Water molecules stick together because of hydrogen bonds. These bonds give water special properties. For example, water has high surface tension, and can dissolve many substances. Water exists in three forms on Earth: solid (ice), liquid (water), and gas (water vapor). The word "water" comes from the Old English word wæter.
About 71% of Earth’s surface is covered by water. Most of this water (about 97%) is in the oceans. This water is salt water, which we cannot drink or use for farming. Only 3% of Earth’s water is fresh water, and even that is not easy to get. 69% of all fresh water is frozen in glaciers and ice caps. 30% is stored underground in aquifers. Less than 1% is in lakes, rivers, and swamps. If you look at all the water on Earth, only about 1% can be used by us. And most of that water is found underground. Water is always moving in a cycle. This is called the water cycle. It includes:
 Evaporation (water turns into vapor),
 Transpiration (plants release water vapor),
 Condensation (vapor forms clouds),
 Precipitation (rain or snow falls),
 Runoff (water returns to oceans and lakes).
Water has many unique abilities. One is that it expands when it freezes. This makes ice less dense than liquid water, so ice floats. Water also has a high specific heat capacity. It can absorb or lose a lot of heat without changing temperature much. This helps keep Earth's climate stable. Water’s surface tension lets it form droplets. It also lets small insects walk on water. Water is an excellent solvent. It can dissolve more substances than any other liquid. This is why it is called the "universal solvent." However, it cannot dissolve oily or nonpolar substances well. These special abilities come from water's polar nature and the hydrogen bonds between them.
Water is important for all living things. Every kind of life we know needs water to survive. This includes tiny living things like bacteria, archaea, and protists, and bigger ones like fungi, plants and animals. The human body is about 50-60% water. Water helps move nutrients, gases, and waste inside the body. Inside cells, water is where most chemical reactions happen. It also helps cells keep their shape. Water is needed for digestion in animals, and photosynthesis in plants. It also helps control body temperature. Without water, life could not exist. That is why water is one of the most important substances for all living things.
Water is also very important to the world economy. About 70% of the fresh water people use goes to farming. Water is used to grow crops and raise animals. Fish from oceans, lakes, and rivers are an important source of food. Many products, like crude oil and other goods, are moved around the world by ships through oceans, rivers, and canals. Water is also used to heat and cool buildings and machines. Because it can dissolve many substances, it is very useful in factories, cooking, and cleaning. Water can also be used to make electricity, using hydroelectric plants. It is also used for fun activities like swimming, boating, fishing, diving, ice skating, snowboarding, and skiing.
Many civilizations in history began near rivers or other places where they could get water easily. For example, Mesopotamia began between the Tigris and Euphrates rivers. Ancient Egypt depended on the Nile. The Indus Valley civilization started near the Indus River. Ancient Rome was built near the Tiber River. Even today, many big cities like London, New York, and Shanghai grew near water. Being close to rivers or oceans made it easier to trade and travel. Islands with good harbors, like Singapore, also became rich and powerful because ships could stop there easily. In dry places like North Africa and the Middle East, clean water has always been important. Having water often made the difference between a small village and a strong civilization.
Water is not just found on Earth. Scientists have discovered water in many places in space. Ice has been found on Mars, and even on the Moon. Some moons in our solar system, like Europa and Ganymede (around Jupiter), and Enceladus (around Saturn) may have liquid water under their icy surfaces. Water vapor has also been found in the atmosphere of some exoplanets. These are planets that orbit stars far away from our solar system. Water has even been found in clouds of gas and dust in space where new stars are being born.
 History 
 In the Universe 
Shortly after the Big Bang, around 13.8 billion years ago, the universe was a hot, dense soup of particles. After 380,000 years, the universe expanded and cooled down enough for the first atomic nuclei to form in a process known as Big Bang nucleosynthesis. This produced mostly hydrogen, with smaller amounts of helium and trace amounts of lithium and beryllium. Oxygen and heavier elements did not yet exist, meaning water could not yet form.
Hundreds of millions of years later, the first stars were made from clouds of hydrogen and helium. Inside these stars, nuclear fusion began to produce heavier elements. In massive stars, fusion of lighter elements created heavier elements like carbon, nitrogen, and finally oxygen (a key ingredient for water). When these massive stars reached the end of their lives, they exploded as supernovae. This scattered those elements, including oxygen, into the interstellar medium.
Now that hydrogen and oxygen existed in the universe, they began to react and form water (H₂O). This happened mainly in molecular clouds. Here, water could form in two ways. On dust grains, hydrogen and oxygen atoms stuck to the surface can react to form water ice. In hot places inside the molecular cloud like around young stars, hydrogen and oxygen gas could react to form water vapor.
As molecular clouds collapsed to form new stars, protoplanetary disks (flat disks of gas and dust moving around the star) formed around these young stars. Water in these disks could be found as water vapor or ice. This depended on how close or far away the water was from the star. The "snow line" is a place far away from the star where it is cold enough for water to freeze and turn into ice. Inside this line, water stays as a gas, but beyond it, water becomes ice. This ice allowed particles to clump together and form planets. Water got trapped in icy planetesimals, comets, and asteroids. In the inner parts of star systems, it was usually too warm for ice, so most water there was in the form of vapor. Some water may have arrived later when comets or water-rich asteroids from the colder outer regions crashed into these inner planets, bringing ice that had formed far from the star.
On some planets and moons, the conditions were just right for water to exist as a liquid, solid (ice), or gas (vapor). Earth is the best and only example we know of. Because it is the right distance from the Sun and has a protective atmosphere, it has had oceans of liquid water for billions of years. Other places, like the moons Europa, Enceladus, and Ganymede, have oceans hidden under thick layers of ice. Mars has signs that it once had rivers and lakes long ago. Comets and asteroids still hold water from the early days of the solar system.
Today, water continues to be everywhere but mostly frozen or in vapor form. It found in molecular clouds, where stars and planets are still being made. It can also be found in interstellar space as ice on dust grains. It has also been found in the atmospheres of exoplanets. At the center of galaxies, massive amounts of water, billions of times the amount on Earth has been found around black holes. But, liquid water remains extremely rare, because it requires a very narrow set of conditions. Earth is unique because it contains liquid water on its surface.
 On Earth 
One of the biggest mysteries in astronomy is where Earth's water came from. Scientists are still trying to answer this question. Earth is special because it is the only rocky planet in our Solar System with oceans of liquid water on its surface. The other rocky planets, Mercury, Venus, and, Mars do not have large amounts of liquid water on their surface. Liquid water is important because every living thing we know needs it to survive. Earth has liquid water because it is in just the right spot in space. This spot is called the habitable zone. It is not too close to the Sun, where water would evaporate. It is also not too far away, where water would freeze. This perfect distance helps keep water in its liquid form on Earth.
There are many ideas about how Earth got its water. Most of these ideas fall into two main groups. One idea is that Earth already had the right ingredients (hydrogen and oxygen) when it formed, and those combined to make water. The other idea is that water came from space. It was carried by asteroids or comets that crashed into Earth after it formed. Some scientists think both of these ideas could be true. Earth might have gotten its water from more than one source. That makes the mystery a bit more complex, but researchers are trying their best to understand what happened in the early Solar System and how water ended up on our planet.
Earth formed about 4.54 billion years ago, after the Sun was born from a huge cloud of gas and dust. The leftover material from that cloud became the rest of the Solar System, including Earth. One idea is that Earth was born with everything it needed to create oceans, lakes, and rivers. But there is a problem. The early Solar System was extremely hot, especially near the center where Earth formed. Any water on the surface would have turned into gas and escaped into space. Another idea is that Earth’s water may have come from deep inside the planet. Water might have been trapped inside rocks deep underground when Earth was forming. This water was safe from the heat because it was hidden inside minerals in Earth's mantle. Over time, volcanoes released that water as steam. When the steam cooled, it turned into rain that helped form oceans and rivers.
Another idea is that Earth may have created its own water. Powerful space telescopes have seen young planets far away, that are surrounded by thick clouds of hydrogen gas. Scientists think that when Earth was very young, it might have had a lot more hydrogen in its atmosphere than it does today. Right now, Earth’s atmosphere is mostly nitrogen, and has almost no hydrogen. One idea suggests how hydrogen gas from the atmosphere could react with molten rock (magma) on the early Earth. This reaction could have produced large amounts of water. As the surface cooled and hardened, this water would have stayed on the planet, forming oceans and lakes.
A long time ago, the inner Solar System was a dangerous place. Between 4.0 and 3.8 billion years ago, the outer planets (Jupiter and Saturn) moved around and changed their orbits. Their powerful gravity sent icy space rocks flying toward the inner planets, including Earth. This time period is called the Late Heavy Bombardment. Many of these space rocks crashed into Earth, and scientists think they could have brought water with them. At first, people thought the water mainly came from comets. But space missions like Giotto (which visited Halley's Comet in 1986) and Rosetta (which visited another comet from 2014 to 2016) found that the water on comets is different from the water in Earth’s oceans. That means comets probably weren't the main source. Instead, scientists now think asteroids and meteorites brought most of the water. For example, a spacecraft called Hayabusa2 brought back pieces of an asteroid named Ryugu. Scientists found that the water trapped in its rocks looks like Earth’s ocean water. Ryugu is made of the same stuff as a type of meteorite called CI chondrites, which could have delivered up to 30% of the water in Earth’s oceans.
Scientists use ancient rocks to figure out when water first appeared on Earth. One kind of rock they use is called pillow basalt, which forms when a volcano erupts underwater. One of these rock was found in the Isua Greenstone Belt in Greenland. It is about 3.8 billion years old. This tells us that there was liquid water on Earth at that time. More of these very old rocks can be found in Canada, in a place called the Nuvvuagittuq Greenstone Belt. Some studies of these rocks also say there was water about 3.8 billion years old. Other studies suggest there was water 4.28 billion years. If there was water, like oceans, even earlier than that, we don't know yet. That might be because the Earth’s surface is always changing over time. Old rocks can be destroyed or buried through processes like plate tectonics and recycling of the crust, which can erase early signs of water. In 2020, scientists suggested that there might have been enough water to fill the oceans immediately after Earth formed.
To understand what Earth was like after it formed, scientists study rocks called zircons. Unlike most rocks, zircons are very tough. They can survive for billions of years, making them useful for studying early Earth. Zircons show that there was liquid water and an atmosphere 4.404 billion years ago, not long after Earth formed. This creates a problem, because the cool early Earth hypothesis says that Earth was cold enough to freeze water between 4.4 and 4.0 billion years ago. Other zircon studies from ancient Australian rocks suggest that plate tectonics may have started around 4 billion years ago. If that's true, Earth may have been similar to today, instead of being hot and covered in carbon dioxide. Plate tectonics helps trap carbon dioxide, which cools the planet and allows solid rock and liquid water to form.
 In human civilization 
In early human history, people survived by hunting animals and gathering plants. They often moved around and stayed close to sources of water or carried water around. But about 12,000 years ago, during the Neolithic revolution, humans started farming and raising animals. To do this, they needed a steady supply of water. Areas with rich soil and regular water made farming possible. This let people settle in one place and live in larger groups. Water also provided food, like fish and other water animals, and helped people travel using simple boats like canoes.
The first human civilizations began in river valleys, where there was plenty of fresh water and good soil for farming. For example, Mesopotamia, known as the "Cradle of Civilization," grew between the Tigris and Euphrates rivers. People there built irrigation canals to bring water to their crops. In Ancient Egypt, the Nile river was very important. It helped people grow food, raise animals, and move goods and people around. The Indus Valley civilization grew near the Indus River. They built advanced water systems, like wells, drains, and public baths. In Ancient China, the Yellow River helped northern China grow, but it also flooded a lot and caused many deaths. That is why it was called both "China’s pride" and "China’s sorrow." In Ancient Rome, people built aqueducts. They were long channels that carried water from far away places into cities. This water was used for farming, public baths, toilets, and even homes.
In the earliest civilizations, rivers and seas were very important for transport and trade. They made it easier to move heavy goods over long distances. In Mesopotamia, the Tigris and Euphrates rivers connected cities like Ur and Babylon. In Egypt, the Nile River helped people trade from Nubia in the south all the way to the Mediterranean Sea. The Phoenicians were great sailors who built strong ships and set up trade colonies around the Mediterranean. Busy ports like Alexandria, Athens, Tyre, and Carthage became rich and full of culture because of sea trade. In Medieval Europe, rivers like the Danube, Rhine, and Seine helped create strong trade networks. Cities like Venice and Genoa became powerful by trading across the sea. In the 1400s, countries like Portugal, Spain, England, and the Netherlands began exploring the world by sea. Christopher Columbus’s voyages opened up the Atlantic Ocean. This connected Europe, Africa, and the Americas in what became known as the Columbian Exchange. Later, the British and the Dutch East India Company built huge trade empires using powerful ships and ocean routes.
As cities got bigger with more people, their water systems could not keep up with the growing population. This led to more disease outbreaks. This was before people understood how germs worked. Diseases like typhoid, cholera, and dysentery spread quickly through dirty water and killed millions of people over the centuries. In Medieval Europe, cities did not have good plumbing. Waste flowed through open sewers in the streets and often mixed with drinking water. This caused many deadly epidemics. In the 1800s, London had several major cholera outbreaks. At first, people thought the disease came from bad air, called “miasma.” But in 1854, a doctor named John Snow proved that cholera was actually spread through dirty water. He traced the outbreak to a single water pump on Broad Street. People learned that having water was not enough. It had to be clean and kept away from waste. In the late 1800s and early 1900s, cities began improving public health by building better water systems. Engineers created piped water networks, storage tanks, and pumping stations to bring clean water to homes. They also built underground sewer systems to safely carry away human waste. Cities like London, Paris, and New York only made these changes after big epidemics showed how serious the problem was. New water treatment methods like sand filtering and adding chlorine helped kill germs and made water safer to drink.
A long time ago, ancient Greek thinkers like Thales of Miletus believed that water was the basic building block of everything in the world. Around 250 BCE, Archimedes used water to figure out the volume of an object by seeing how much water it pushes away when put in water. During the Renaissance, Leonardo da Vinci studied how water flows and how it helps wear away rocks over time. He helped build canals and other things to help control water. Galileo Galilei looked at why some things float on water and others do not. He also studied tides, the regular rising and falling of the sea. By the late 1700s, Antoine Lavoisier figured out that water was not an element, but a compound made from hydrogen and oxygen.
Today, about 70% of all the freshwater we use around the world goes to agriculture, making farming the biggest user of water. Plants need water to grow, animals need it to live, and irrigation helps farmers grow crops even in dry areas. In modern times, how much water a country has can affect whether it can grow enough food for its people or if it has to buy food from other countries. Places with lots of water, like the United States, Brazil, China, and India, are major food producers. These countries grow extra crops like wheat, corn, soybeans, and rice, and sell them to other countries. Having lots of rain, rivers, underground water, and good systems like dams and canals gives these countries a big advantage. But countries with very little water, like Saudi Arabia, Qatar, the UAE, and Kuwait have trouble growing enough food. They do not have enough freshwater or good land for farming, so they import most of their food from other places. Fish are also an important source of food for the world. Over 1 billion people depend on fish as their main source of protein, especially in places near rivers and oceans. Fish farming, called aquaculture, has allowed us to raise fish instead of looking for them.
Even today, oceans and rivers are still the main way we move goods around the world. In fact, about 80% of all global trade by volume travels by sea. Oceans, rivers, and canals are great for moving things like fuel, raw materials, and products because it is cheaper than using trucks or planes. Some water routes are especially important. The Suez Canal, Panama Canal, Strait of Hormuz, and Strait of Malacca are key paths for global trade. Large ports like those in Shanghai, Rotterdam, Singapore, and Los Angeles help grow their countries' economies. Big rivers like the Mississippi in the U.S., the Yangtze in China, and the Danube in Europe are also important. They help move large amounts of goods inside countries cheaply.
Modern water systems help bring clean water to billions of people around the world. Dams and reservoirs store water for drinking, farming, flood control, and even to make electricity. Famous examples include the Hoover Dam in the U.S. and the Three Gorges Dam in China. Pipelines and aqueducts move water from places that have a lot of it to places that do not have much and big cities. For example, Los Angeles gets much of its water from places far away. In very dry regions like the Middle East, Israel, and parts of Australia, desalination plants turn salty seawater into fresh drinking water. But this process uses a lot of energy. Wastewater treatment plants clean dirty water from homes and businesses so it does not pollute rivers and lakes. Sometimes, this cleaned water is reused for farming or industry.
The world still faces big problems with water. More than 2 billion people live in places where there is not enough water. In areas like India, the southwestern U.S., and the Middle East, people are using up groundwater faster than it can be replaced. Because of this, there might not be enough water in the future. Climate change is making things worse. It causes longer droughts, changes where and when rain falls, and reduces the amount of snow in mountains. Snow is important because it slowly melts releasing water into rivers over time. Pollution is also a big problem. Factories, farms, and untreated sewage can make rivers and lakes dirty. Rising sea levels are pushing saltwater into underground water supplies near the coasts, making them unsafe to drink. More powerful storms are causing floods that city drainage systems can not handle. Because of this, we must protect and manage water carefully for the future.
 Properties of water 
Water is a chemical substance. It is made of two hydrogen atoms and one oxygen atom. Its chemical formula is H₂O. These atoms are held together by something called a covalent bond. At room temperature and normal pressure, water is a liquid. It has almost no color, taste or smell. Water is often called the "universal solvent" because it can dissolve more substances than any other liquid. But it cannot dissolve nonpolar substances like oil very well. Water is also the only common material on Earth that can naturally exist as a solid, liquid, and gas.
A water molecule looks like a bent “V” shape. The angle between the two hydrogen atoms is about 104.5°. This shape happens because of how electrons are arranged around the oxygen atom. Oxygen has six outer (valence) electrons. It uses two of them to bond with two hydrogen atoms (one for each). The other four electrons stay in two pairs, called lone pairs, that do not bond with anything. According to VSEPR theory, all these pairs of electrons want to stay as far apart as possible. This creates a shape like a tetrahedron with four regions: two bonding pairs and two lone pairs. But lone pairs take up more space and push harder than bonding pairs. They push the hydrogen atoms closer together, so the angle becomes smaller than the usual 109.5° of a perfect tetrahedron. That is why the water molecule is bent instead of straight, and why the bond angle is 104.5°.
 Hydrogen bonds 
A water molecule (H₂O) has one oxygen atom and two hydrogen atoms. Oxygen is much more electronegative than hydrogen. This means it attracts electrons closer to itself much more than hydrogen. So, when oxygen and hydrogen share electrons in a water molecule, the electrons spend more time near the oxygen atom. This gives the oxygen atom a partial negative charge (δ⁻). And the hydrogen atoms gains a partial positive charge (δ⁺). So, the water molecule now has a positive side and a negative side. Because of this, the positive hydrogen of one water molecule is attracted to the negative oxygen of another. This attraction is called a hydrogen bond. It is not as strong as a normal chemical bond (like a covalent bond). But, it is strong enough to hold water molecules loosely together. Hydrogen bonding explains many of water’s unusual properties. For example, water's high boiling and melting points, high surface tension, the ability of ice to float on water, and the ability to dissolve many substances.
Water (H₂O) is a liquid at room temperature. This might seem normal until you compare it to similar substances. Water belongs to a group of compounds called hydrogen chalcogenides. These are made when hydrogen bonds with elements from the same family as oxygen: sulfur, selenium, and tellurium. This includes hydrogen sulfide (H₂S), hydrogen selenide (H₂Se), and hydrogen telluride (H₂Te). But, while water is a liquid, the others are all gases at room temperature. The reason is hydrogen bonding. Oxygen is very electronegative (it strongly pulls on electrons) and is small in size. Because of this, water molecules can form strong hydrogen bonds. Each water molecule can form up to four hydrogen bonds with its neighbors. This creates a kind of "stickiness" that holds the molecules together and makes it harder for them to break apart and turn into a gas. That is why water has a high boiling point of 100°C (212°F) for such a small molecule. The other chalcogens (sulfur, selenium, and tellurium) are larger but less electronegative than oxygen. In hydrogen sulfide (H₂S), hydrogen selenide (H₂Se), and hydrogen telluride (H₂Te), the bonds between hydrogen and the other elements are weaker. These molecules do not form strong hydrogen bonds. Instead, they only have weak van der Waals forces, which are easy to break. So these substances boil at much lower temperatures. Hydrogen sulfide (H₂S) boils at –60°C. Hydrogen selenide (H₂Se) boils at –41.5°C. Hydrogen telluride (H₂Te) boils at –2.2°C. That is why they are gases at room temperature, while water is a liquid.
 Cohesion and adhesion 
Water molecules stick to each other. This is called cohesion. This happens because each water molecule can form hydrogen bonds with its neighbors. Inside a drop of water, each molecule is pulled in all directions by the other water molecules around it. But at the surface, there are no water molecules above. The hydrogen bonds at the surface of water pulls molecules tightly together, forming a sort of "skin" on the surface. This is called surface tension. This is why water forms droplets. It is also why small insects, like water striders, can walk on water. It is also why small objects like a needle can float if placed gently on water.
Water molecules can stick to other surfaces. This is called adhesion. This especially happens to surfaces that are polar or charged, like glass, plant cell walls, or soil particles. Water's adhesion can be seen when water climbs up the side of a glass container, forming a curved surface called the meniscus. It can also be seen as water spreads out on a leaf or sticks to surfaces like spider webs. Whether water forms flat puddles or round beads depends on the balance between cohesion and adhesion. If water sticks more to the surface, it spreads out. If water sticks more to itself, it forms beads.
Water can climb up a thin tube or narrow space. This is called capillary action. It happens because adhesion pulls water molecules to the sides of a thin tube or pore, while cohesion pulls other water molecules along with it. In plants, capillary action helps water move from the roots to the leaves. As water evaporates from the leaves, it pulls more water up behind it. Adhesion helps the water stick to the sides of the plant's tubes. Cohesion keeps the water molecules connected like a chain, so they move upward together. This allows them to move up against gravity.
 Heat and water 
Water is very good at staying at the same temperature. It does not heat up or cool down quickly. This is because water has a high specific heat capacity. That means it takes a lot of heat to make water warmer, and it cools down slowly too. Specific heat is the amount of heat needed to change the temperature of 1 gram of a substance by 1°C. For water, this is 1 calorie. That is much higher than most other common substances. For example, alcohol only needs 0.6 calories to do the same, so it heats up faster than water.
If you touch a metal pot with warm water inside, the metal might feel hotter than the water. That is because metal heats up faster than water. Water takes longer to warm up because water molecules are held together by hydrogen bonds. When heat is added, much of the energy goes into breaking the hydrogen bonds between water molecules. Once those bonds are broken, the molecules can move faster, and the temperature rises. So instead of heating up quickly, water stores heat by breaking the hydrogen bonds first. When water cools down, the hydrogen bonds form again and release heat. This helps keep temperatures steady. Oceans and lakes can absorb heat from the sun during the day or in summer and release it slowly at night or in winter. That is why places near water usually have milder temperatures. Water’s high specific heat also keeps the ocean from getting too hot or too cold. This is very important for ocean life. And because our bodies are mostly made of water, this also helps us keep a steady body temperature.
Water molecules usually stay close together. But if some molecules move fast enough, they can break free and escape into the air as gas. This process is called evaporation. Even at low temperatures, the fastest molecules can still escape. This is why a glass of water will slowly disappear over time. Heating water makes its molecules move faster, so it evaporates faster too. The heat of vaporization is the amount of heat needed to turn 1 gram of liquid water into gas. For water, it takes about 580 calories to evaporate just 1 gram at 25°C. This is nearly double the amount needed for ammonia and alcohol. Water’s high heat of vaporization is because of hydrogen bonds. Water molecules are held together through hydrogen bonds. To vaporize water, these bonds must be broken, which takes a lot of energy. The energy does not raise the temperature. It goes into breaking the hydrogen bonds. That is why water takes a long time to boil and releases a lot of heat when it condenses.
This high heat of vaporization has important effects on Earth. Tropical oceans take in a lot of heat from the Sun. Some of this heat is used to evaporate water. When that water vapor travels to cooler places and turns back into rain, it releases heat. This helps balance Earth’s climate and spread heat around the planet. Evaporation also cools things down. When water evaporates, the fastest (hottest) molecules leave first. This lowers the temperature of the water that is left behind. This is called evaporative cooling. It helps keep lakes, plants, and animals from getting too hot. When we sweat, the sweat takes heat from our skin as it evaporates. This is why sweating cools down. On hot, humid days, the air already has a lot of water vapor. That makes it harder for sweat to evaporate, so we feel even hotter. Some animals that cannot sweat, like elephants, cool themselves by spraying water on their skin.
It also takes a lot of energy to melt ice. This is called the heat of fusion. The heat of fusion is the amount of energy needed to change 1 gram of a substance from solid to liquid at its melting point. For water, this is 334 joules per gram (J/g). That is higher than most other substances, especially for a molecule as small as water. When water freezes into ice, its molecules form a crystalline structure held together by hydrogen bonds. To melt ice, you need enough energy to break many of these bonds. The heat added goes into breaking these bonds, but does not increase the temperature. The water that is produced also remains at 0°C until all of the ice is melted. The same amount of energy needed to melt ice could warm that same ice from –160°C all the way up to 0°C. Ice and snow can take in heat without melting right away. This helps keep temperatures from changing too quickly. In cold places like the North and South Poles or high mountains, this helps keep the temperature more steady. Before we had refrigerators, people used ice to keep food cool because it stayed frozen for a long time.
 Density of ice 
Water is one of the only substances that becomes less dense when it freezes. This means that ice floats on water. Most substances get smaller and denser when they freeze. But water is different. It expands (or gets bigger) when it freezes. This strange behavior happens because of hydrogen bonds. At temperatures above 4°C, water acts like most liquids. It expands when heated and shrinks when cooled. But between 4°C and 0°C, something strange happens. As the water gets colder, the molecules slow down. They do not have enough energy to break the hydrogen bonds between them. At 0°C, the molecules line up into a solid crystal shape. Each molecule connects to four others with hydrogen bonds. These bonds hold the molecules further apart. So the ice takes up more space than the liquid water, even though it has the same number of molecules. That is why ice is about 9% less dense than water at 4°C. When ice melts, the bonds break and the molecules move closer together. Water is densest at 4°C. It becomes less dense if it gets warmer or cooler from that temperature.
The fact that ice floats is very important for life on Earth. If ice sank, lakes and oceans could freeze all the way to the bottom. This would make it hard or even impossible for fish and other living things to survive. Instead, ice floats on top, and acts like a blanket. This helps keep the water below from freezing. Fish and other organisms can stay alive under the ice. Also, floating ice provides homes for animals like polar bears and seals.
 Water as a universal solvent 
When you drop a sugar cube into a glass of water, the sugar slowly dissolves and spreads out. This creates a mixture. This type of mixture is called a solution. In a solution, the solvent is the substance that does the dissolving (in this case, water), and the solute is the substance that gets dissolved (the sugar). If water is the solvent, the solution is called an aqueous solution.
Water is a very good solvent. Because of this, it is often called the "universal solvent". This is because it can dissolve more substances than any other substance. This happens because water molecules have slightly positive and negative parts. These parts attract other charged or polar substances. For example, when you add salt (sodium chloride, or NaCl) to water, it breaks into sodium (Na⁺) and chloride (Cl⁻) ions. The negative side of water pulls on the sodium, and the positive side pulls on the chloride. Water molecules surround each ion. They then pull them away from the salt crystal. After that, they spread them out in the water. This group of water molecules around an ion is called a hydration shell. Other ionic compounds, like potassium chloride, also dissolve in water this way. Seawater is full of dissolved ions like these. But a substance does not have to be made of ions to dissolve in water. Polar molecules like sugar can also dissolve. This is because they can form hydrogen bonds with water. Even large molecules, like proteins, can dissolve in water if they have polar or charged areas on their surfaces.
Water is the main solvent for living things. Many important substances are dissolved in the water in blood, plant sap, and cells. Any substance that mixes well with water is called hydrophilic (water-loving). Some hydrophilic substances do not dissolve in water. For example, some molecules in cells are too big to dissolve. Another example is cotton. Cotton is made up of giant molecules of cellulose. Cellulose does not dissolve in water. It has lots of positive and negative parts that can form hydrogen bonds with water. Water sticks to the cellulose. That is why cotton towels drys things well, but does not dissolve in the washing machine. Plants also use cellulose in the tubes that carry water from roots to leaves. Water sticks to the hydrophilic walls of these tubes, helping it move upward against gravity. On the other hand, substances that do not mix with water are called hydrophobic (water-fearing). These include oils and fats. They don't dissolve because they do not have charges that attract water. That is why oil and water do not mix. Hydrophobic molecules can be found in cell membranes. Without them, cells would dissolve in water. Life would be impossible.
 States of water 
Water can exist in three main forms: solid, liquid, and gas. These are called states or phases. Which one water is in depends on the temperature and pressure.
When people say "water" in everyday life, they usually mean liquid water. This is the form that comes from taps, fills oceans, rivers, and lakes, and is used for drinking, cooking, and cleaning. Liquid water is the most common form found on Earth's surface. When water gets cold enough, it freezes and becomes a solid called ice. Ice can be in the form of hard cubes (like in your freezer) or soft, loose crystals, like snow. There are also other strange kinds of ice. These are often found in extreme environments like outer space deep inside Uranus. When water gets hot enough, it turns into a gas called water vapor. This is what we see as steam rising from boiling water.
Water can also exist in a very strange state called a supercritical fluid. This only happens at extremely high temperatures above (374°C or 705°F) and very high pressures (above 22.064 megapascals). Here, water acts like a gas and a liquid at the same time. It can flow like a liquid and spread out like a gas. Supercritical water is useful because it can dissolve many things that normal water cannot. It can dissolve nonpolar organic compounds like oil. This strange state of water does not happen naturally on Earth’s surface. But it can happen deep in the ocean. One example is near hydrothermal vents. This happens at around 2200 meters deep. The ocean is much deeper than that on average at about 3800 meters.
 Changing states 
A phase diagram is a special graph. It shows how a substance like water changes between solid, liquid, and gas depending on the temperature and pressure. On this graph, the bottom (horizontal) line shows temperature. The side (vertical) line shows pressure. The graph is divided into three parts. One part shows where water is a solid (ice). Another part shows where it is a liquid (water). And another part shows where it is a gas (steam). There is a special point on the graph called the triple point. At this temperature and pressure, water can exist as a solid, liquid, and gas at the same time. For water, this happens at 0.01 °C and a pressure of 611.657 pascals.
At normal air pressure (1 atmosphere), water freezes into ice at 0 °C (32 °F) and boils into steam at 100 °C (212 °F). The freezing point is the temperature at which water turns to ice. The boiling point is the temperature at which water turns into gas. Water does not need to be boiling to become gas. Even at low temperatures, some water molecules can move fast enough to evaporate. This is why a glass of water when left alone will slowly dry out. But when water is heated, the molecules move faster and evaporate quicker. When water reaches 100 °C, bubbles of water vapor form inside the liquid. These bubbles rise to the top and release steam into the air.
Water vapor (gas) can turn directly into ice without becoming liquid first. This is called deposition. You can see this when frost forms on cold windows. It also happens when snowflakes form in clouds. In clouds, tiny pieces of dust or pollen help water vapor turn straight into ice. The opposite of deposition is called sublimation. This is when ice turns straight into water vapor without becoming a liquid. One use of sublimation is in freeze-drying food. a method of preserving food. First, the food is frozen. Then it is put into a vacuum (a space with no air). The ice inside the food turns into vapor. This leaves the food dry, without using heat.
Water usually freezes at 0 °C (32 °F) at normal air pressure. But in special conditions, pure water can stay liquid even it is colder than that. If it is not shaken or disturbed, it can cool all the way down to about –42 °C (–44 °F) without freezing. This is called supercooling.
The melting and boiling points of water change with pressure. For most things, if you add more pressure, they melt at a higher temperature. But water is different because ice is less dense than liquid water. That is why ice floats. When pressure is added to ice, the melting point actually goes down. That means ice can melt even when it is colder than 0 °C if there is enough pressure. This can happen deep under a glacier. The heavy ice on top pushes down with a lot of pressure. This pressure can melt the ice under it, even though it is very cold. That is how lakes can form under glaciers.
Steam (which is water in gas form) takes up much more space than liquid water. That means it is less dense. When the pressure is high, it becomes harder for water to boil, so it needs to be hotter to turn into steam. In places with a lot of pressure, water can stay as a liquid even when it gets hotter than 100 °C (212 °F), which is the normal boiling point. For example, in geysers like Old Faithful, water can get over 205 °C (401 °F) without boiling. And near underwater volcanoes called hydrothermal vents, water can reach 400 °C (752 °F) and still stay liquid.
At sea level, water boils at 100 °C (212 °F). But when you go up higher like up the mountains, the air pressure gets lower. When pressure is lower, water boils at a lower temperature. For every 274 meters (or about 900 feet) you go up, the boiling point goes down by about 1 °C. For example, at 274 meters (about 900 feet), the boiling point becomes 99°C (210.2°F) instead of 100°C (212°F). That is why food takes longer to cook at higher altitudes. The water boils before it gets really hot. A pressure cooker works the opposite way. It traps steam inside, which raises the pressure. This lets water boil at a higher temperature, so food cooks faster. In places with no air at all, like in a vacuum, water can even boil at room temperature. This is because there is no pressure holding the water molecules together.
 Taste and odor 
People often say that water has no taste or smell. But in real life, most of the water we drink has some taste or smell. This is because there are usually tiny amounts of other substances dissolved in the water. Pure water does not have a taste, but our tongues can tell if something is mixed in. For example:
 Salts in water can give it a “mineral” taste, like water from springs.
 Water that is very acidic tastes sour.
 Water that is very basic (alkaline) tastes bitter.
 Tap water often has chlorine added to kill germs. This can give it a chemical or medicine-like taste.
 Metals like iron or copper can cause a metallic taste. This can be found in water from old pipes.
Even tiny amounts of these substances can change the taste. How strongly people taste them can depend on how cold or warm the water is and even a person's genes.
 Water can smell earthy or musty. This often come from natural chemicals like geosmin or 2-methylisoborneol (MIB) made by algae or bacteria in lakes and rivers. 
 A rotten egg smell means the water might have hydrogen sulfide gas in it. 
 Tap water might smell a little like chlorine, from the treatment process.
Some of these smells are so strong that the human nose can detect them even in very small amounts. Some animals, like frogs, can even smell water itself.
 Mechanical properties 
Water is often called incompressible. This means that even if you push on it really hard, it doesn't shrink much. For example, at the bottom of the ocean, about 4 kilometers (2.5 miles) deep, the pressure is 400 times greater than at sea level. But water only gets about 1.8% smaller. This happens because water has a high bulk modulus (about 2.2 gigapascals). This means it resists being squeezed.
Viscosity is how easily a liquid flows. Water has low viscosity, so it flows quickly and easily, like in rivers or through pipes. Honey or syrup have high viscosity, so they flow slowly and are thick. Water flows smoothly through rivers, pipes, and the human body (like in blood vessels and cells). Viscosity changes with temperature. When a liquid gets warmer, it becomes thinner and flows more easily. When it gets colder, it becomes thicker and flows more slowly. So, warm water flows faster, and cold water flows slower. Water is called a Newtonian fluid. This means its viscosity stays the same even if you stir it fast or slow.
Sound travels through water at about 1,400 to 1,540 meters per second, depending on how warm, salty, or deep the water is. That is over 4 times faster than in air. Whales use sound to talk and find food underwater. Humans use tools like sonar to find things under the sea.
 Electrical properties 
Water is a polar molecule. This means it has slightly charged ends. In water molecules, the hydrogen atoms have a small positive charge, and the oxygen atom has a small negative charge. This happens because oxygen pulls electrons closer to itself. That is because oxygen is more electronegative. It likes to attract electrons more than hydrogen does. This polarity helps water surround and pull apart other substances, especially those made of charged particles, like table salt (NaCl). When salt is added to water, the negative part of water (the oxygen) surrounds the positive sodium ions (Na⁺). The positive part (the hydrogen) surrounds the negative chloride ions (Cl⁻). This helps break the salt apart and keep the ions floating around in the water.
Water also has a high dielectric constant. It is about 80 at room temperature. That is much higher than most other liquids. This means water can reduce the electrical attraction between opposite charges. As a result, ions (like those from salt) can separate more easily in water. This is why it is so good at dissolving electrolytes. This makes it easier for ions to stay separate and move around freely. This is important for conducting electricity in biological and chemical systems. Thanks to its polarity and dielectric nature, water is one of the best solvents in the world. That is why it is called the "universal solvent".
Water can go through a special process called autoionization (also called self-ionization). This means that two water molecules can react with each other to make two new particles: a hydronium ion (H₃O⁺) and a hydroxide ion (OH⁻). One water molecule, takes a hydrogen from the other becoming a hydronium ion while the other is left with one hydrogen becoming a hydroxide ion.
The reaction looks like this:
 H2O + H2O H3O+ + OH−
This reaction does not happen often. At room temperature (25 °C), only a tiny number of water molecules do this. In pure water, the amounts of H₃O⁺ and OH⁻ are each 1 × 10⁻⁷ mol/L (moles per liter). That tiny amount makes water neutral and gives it a pH of 7. The pH scale, which tells us if something is acidic or basic, is based on this. Because there are so few ions, pure water does not conduct electricity well. That means pure water is more like an insulator than a conductor.
But water can dissolve ionic substances like salt very well. When you add even a little table salt (NaCl) to water, it releases lots of ions. The conductivity goes up a million times. That is why tap water and seawater conduct electricity so well. Seawater, for example, has ions like Na⁺, Cl⁻, and Mg²⁺, making it highly conductive. This matters in real life. Distilled water, which has no ions, can't carry electricity. But regular water, with minerals or salts in it, can carry electric current. This is important in batteries, electrolysis, and even in cells in your body.
 Optical properties 
In small amounts, water looks clear, but pure water actually has a slight blue tint. You can see the blue color more easily when you look at a large amount of water, like in a swimming pool, lake or ocean. The color comes from the way water interacts with light. Pure water absorbs some colors of light more than others. Those colors include the red, orange, and yellow parts of sunlight. This leaves more blue light to be reflected into our eyes. This is why water looks blue. You cannot see this in a glass of water. You can only see this when you are looking at deeper water, like in a swimming pool or lake. The deeper the water, the more light gets absorbed, and the more the blue color is seen. If water has something dissolved in it or tiny particles floating in it, the color can change. For example, algae and organic matter can make water look green or brown. Minerals and sediments in the water can change its color. Tannins from decaying plants can give water a tea-like, brownish color.
Visible light can mostly go through water. Blue and green light go the deepest in water. On the other hand, red, orange, and yellow light gets absorbed by the water, so they do not go very deep. In clear ocean water, sunlight can reach down to about 200 meters. This upper layer is called the photic zone. It is where there is enough light for plants and tiny algae like phytoplankton to do photosynthesis. Deeper than that, there is not enough light for plants to do photosynthesis.
Water bends light because it has a higher refractive index than air. The refractive index of water at room temperature (20°C or 68°F) is about 1.333. The refractive index of air is about 1.0. This means that when light enters water from the air, it slows down and bends. This is called refraction. It is this bending of light that causes a straw to look bent or broken in a glass of water. It is also why things under water look closer or larger than they actually are. Ice has a slightly lower refractive index (about 1.31). Because of this, light bends a bit less when passing through ice than through liquid water. The refractive index of water is similar to some liquids like ethanol and alkanes. But, it is lower than substances like glycerol, benzene, carbon disulfide, or glass (which range from 1.4 to 1.6). Also, the refractive index of water can change a little depending on the how hot or how cold it is, the pressure, or how much salt is in the water.
 Chemical reactions of water 
Water can react with some metals. It reacts with metals more reactive than hydrogen. When this happens, the metal reacts with water to make hydrogen gas and a metal hydroxide. Some metals, like the alkali metals (such as lithium, sodium, and potassium), react very strongly with water. Alkaline earth metals like calcium and magnesium react less violently. For example, sodium reacts violently and makes sodium hydroxide and hydrogen gas:
2Na + 2H2O → 2NaOH + H2
This reaction gives off a lot of heat (exothermic). It can even cause the hydrogen gas to catch fire.
Water is amphoteric. This means it can act like an acid or a base. This depends on what it is reacting with. When water is with a strong base, it gives away a hydrogen ion (H⁺) and acts like an acid. When water is with a strong acid, it takes in a hydrogen ion and acts like a base.
Water can also react with itself in a process called self-ionization:
H2O + H20 ⇌ H3O+ + OH-
This creates a hydronium ion (H₃O⁺) and a hydroxide ion (OH⁻). This reaction does not happen much in water. It helps set the pH scale, which tells us how acidic or basic a liquid is.
Water can also break one molecule into two smaller ones in a process called hydrolysis. The word comes from Greek: "hydro" meaning water, and "lysis" meaning to break or unbind. In hydrolysis, one molecule breaks into two molecules. A water molecule then breaks apart into a hydrogen ion and a hydroxide ion. The hydrogen ion attaches itself to one of the two new molecules. The hydroxide ion attaches itself to the other molecule. In industry, hydrolysis is used to break down compounds like esters or salts. In biology, proteins are broken into amino acids through hydrolysis. Fats (lipids) are broken into glycerol and fatty acids. Carbohydrates, such as sucrose, are broken into simpler sugars like glucose and fructose:
C12H22O11 (sugar) + H2O → C6H12O6 (glucose) + C6H12O6 (fructose)
Hydrolysis is the opposite of a condensation reaction. Condensation combines two molecules and releases water. Hydrolysis breaks one molecule into two smaller ones by adding water.
Water can be broken down into hydrogen gas (H₂) and oxygen gas (O₂), using a process called electrolysis. In this process, an electric current is passed through water that contains small amounts of an electrolyte like sulfuric acid or salt. This helps the water conduct electricity. The electricity breaks down the water molecules:
2H2O → 2H2 + O2
Electrolysis is important because it produces clean hydrogen fuel when powered by renewable energy like solar or wind. This is often called green hydrogen. It can be used to store energy, power fuel cells, or replace fossil fuels in industry and transportation.
 On Earth 
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   Earth's water distribution.svg
   Earth_water_distribution_ppm_chart.svg
   A graphical distribution of the locations of water on Earth
   Visualisation of the distribution of water on Earth (by volume). Each tiny cube (such as the one representing biological water) corresponds to approximately 1,000 km3 of water. This amount of water has a mass of about 1 trillion tonnes (200,000 times that of the Great Pyramid of Giza or five times that of Lake Kariba, arguably the heaviest man-made object). Comprising 1 million tiny cubes, the entire cube would measure about 1,102 km on each side.
Hydrology is the science that studies how water moves, where it is found, and its quality all over the Earth. It is part of a larger group of sciences that study water in different places and forms:
 Hydrography studies where water is located on Earth's surface.
 Hydrogeology focuses on groundwater, water stored underground.
 Glaciology studies ice and glaciers.
 Limnology looks at inland water bodies like lakes and rivers.
 Oceanography studies the oceans.
 Ecohydrology explores how water interacts with ecosystems and living things.
All the water on Earth (in oceans, rivers, lakes, ice, underground, and even in the air) is called the hydrosphere. The Earth holds about 1.386 billion cubic kilometers of water. Water on Earth is not distributed equally. Most of the water on Earth is found in the oceans. About 96.5% of all the water on Earth is salt water in the oceans. This cannot used for drinking or farming. That leaves only 2.5% of the Earth's water as fresh water. Of this small percentage of freshwater, most of them are in hard to reach places. Around 68.7% of Earth's fresh water is stored in ice caps, glaciers, and permanent snow. This is mainly in Antarctica and Greenland. Another 30.1% is found as groundwater, stored in aquifers deep under the Earth's surface. This groundwater is an important source of water for wells and springs. It is very important in agriculture and for drinking. Only about 1.2% of all fresh water is water that can be found on the surface of the Earth. This includes water in lakes (about 20.9%), swamps and marshes (2.6%), and rivers (0.49%). Water can also be found in the atmosphere as vapor, clouds, and precipitation, and in soil moisture, permafrost, and living organisms. But these make up only a tiny fraction of all the water on Earth (less than 0.01%).
Fresh water is not evenly distributed across the Earth. Some places have more water than others. Countries like Canada, Brazil, and Russia have large supplies of fresh water because of lots of rivers and rainfall. In contrast, dry places like North Africa, the Middle East, and parts of Central Asia have very limited freshwater. Some tropical and temperate regions get lots of rainfall, while others may go months without much rain.
 Water cycle 
The water cycle (also called the hydrologic cycle) is the constant movement of water through the Earth's atmosphere and surface. Water moves between the air, ground, rivers, oceans, lakes, plants, and even underground. The main parts of the water cycle are:
 Evaporation: Water from oceans, lakes, and rivers changes into vapor (gas) and rises into the air.
 Transpiration: Plants release water vapor into the air through their leaves.
 Condensation: Water vapor in the air turns into clouds.
 Precipitation: Water vapor in the air cools, turns into liquid or solid, and falls back to Earth as rain, snow, or hail.
 Runoff: Water flows across the land into rivers, lakes, and oceans.
The sun is the main source of energy that drives the water cycle. When sunlight heats up water, the water molecules move faster and can turn into vapor. This a process called evaporation. This happens in oceans, lakes, rivers, and even from the land. Plants also release water vapor through their leaves in a process called transpiration. Together, evaporation and transpiration are called evapotranspiration. The term evapotranspiration is commonly used by geologists. Water vapor is invisible to our eyes.
Winds carry water vapor in the atmosphere over long distances. When water vapor cools down, it changes back into liquid water. This is called condensation. This can happen when warm air meets cool air. The water forms tiny drops around dust or salt called condensation nuclei in the air. These drops come together to form clouds. As more droplets stick together, they grow bigger. When they get heavy enough, they fall to Earth as rain, snow, or hail. This is called precipitation.
When precipitation reaches the ground, it can do the following. It can evaporate again. It can flow over the land as runoff into rivers and lakes. Or soak into the ground to become groundwater. Water that flows in rivers and lakes is called surface water. Water that moves underground through soil and rock is called groundwater. Groundwater moves slowly and can come back to the surface through springs. It can also flow into rivers, lakes, or oceans. This shows how surface water and groundwater are connected.
Most water that evaporates from the ocean goes back to the ocean. But wind blows water vapor to land at the same rate it goes back to the ocean. Each year, about 47 trillion tons of water vapor move from the ocean to the land. About 72 trillion more tons of water vapor comes from land evaporation and plants. That adds up to 119 trillion tons of precipitation falling on land each year. Precipitation over land has many forms. Most commonly rain, snow, and hail, with some being fog and dew. Dew are small drops of water that form when warm, wet air touches a cool surface, usually in the early morning. Water droplets in the air may also refract sunlight to produce rainbows.
Water that flows over land collects in places called watersheds. They then travel through rivers, carving out valleys and deltas. These areas usually have very good soil, which is good for farming and building cities. Sometimes, too much water causes a flood. This can happen when rivers overflow or big storms push water onto the land. Other times, there is not enough water. A drought happens when a place gets very little rain for a long time. This is often because of the place or shape of the land.
 Water and Earth's geography 
Water plays an important role in shaping the Earth’s surface and what is happening under it. It helps form landscapes. It breaks down rocks. It even affects volcanic activity from deep under the surface. Water changes the land through both physical actions, like erosion, and chemical reactions, like breaking down minerals in rocks.
Water plays a big role in breaking down rocks on Earth’s surface. This is a process called weathering. There are two main types: physical and chemical. In physical weathering, water gets into cracks in rocks. When it freezes, it expands and makes the cracks bigger. Over time, this causes the rock to break apart. In chemical weathering, water mixes with carbon dioxide from the air or soil. This creates a weak acid called carbonic acid. Carbonic acid can dissolve some types of rock, especially limestone. When this acid gets to limestone underground, it can create large cracks, caves, and tunnels. On the surface, it can create a type of landscape called karst. Here the ground has sinkholes, caves, and holes. One amazing example of karst is the Stone Forest near Kunming, China. It has hundreds of tall, sharp towers of limestone made by water. Another example is Carlsbad Caverns in New Mexico, USA. This park has over 119 caves, all formed by water breaking down limestone. The biggest one, called the Big Room, is so large it could fit six football fields inside.
Once rocks are broken down by weathering, the pieces are moved by a process called erosion. Water moves bits of rock and minerals away. No rock is strong enough to resist weathering and erosion forever. These powerful forces have created some of Earth’s most famous landmarks. For example, the Grand Canyon in Arizona, USA, was made by the Colorado River over millions of years. The canyon is about 446 kilometers (277 miles) long, up to 29 kilometers (18 miles) wide, and about 1.6 kilometers (1 mile) deep.
Water is also very good at moving sediment. Sediment is made up of small pieces of rock, sand, and soil. Rivers, glaciers, rain, and even ocean currents move sediment over long distances. Eventually, this sediment settles in new places. Sediment is important because it adds nutrients to the soil. This helps plants grow. Places with lots of sediment, like riverbanks and deltas, are usually great for farming. They have a lot of different plants and animals. For thousands of years, the Nile River in Egypt flooded every year. This brought about 4 million metric tons of nutrient-rich sediment. Even today, the land next to the Nile is Egypt’s best farmland. Over millions of years, layers of sediment can press together to form sedimentary rocks. These rocks can contain fossils and clues about Earth’s past, like what the climate was like long ago.
Deep inside the Earth, water plays an important role in forming magma. Magma is the hot, melted rock that can lead to volcanoes. The mantle is the thick layer under the Earth's crust. It is made of solid rock even though it is hot enough to melt rocks. This is because the pressure deep inside the Earth is so strong that it stops the rock from melting. But in places called subduction zones, one of Earth's tectonic plates goes under another plate. This brings water down into the mantle. This water lowers the melting point of the rock. This means the rock can start to melt even though it is still under very high pressures. This creates magma, which can rise and cause volcanic eruptions. So, water does not just shape the land on the surface, it also helps cause big changes deep underground. Over millions of years, water has helped shape how Earth looks and behaves.
 In the Universe 
Water is not only found on Earth. It can be found all over the universe. Astronomers have found ice, vapor, and sometimes liquid water in many places in the universe. Water ice has been found on the Moon, Mars, and comets. It has also been found on the icy moons of the outer planets, such as Europa and Enceladus. Even in interstellar space, the space between the stars, water exists as ice around tiny dust grains. It also exists as vapor in molecular clouds where new stars are born. Water has even been found in the atmospheres of exoplanets, planets outside our solar system.
A water molecule is made of two hydrogen atoms and one oxygen atom. Hydrogen came from the Big Bang. Oxygen was created inside big stars, much larger than the Sun. When these stars die and explode, they release oxygen into space. Oxygen can then combine with hydrogen to make water. Huge clouds of gas and dust, called stellar nurseries, are where new stars are born. These places often contain huge amounts of water vapor. For example, the Hubble Space Telescope found water molecules in the Helix Nebula. Water has also been found in young planetary systems around other stars. Around the star Beta Pictoris, which is about 20 million years old, scientists found water in a giant disk of gas and dust. This is likely from comets smashing into each other, asteroids, and forming planets. In the Orion Nebula, one of the biggest and most famous star-forming regions, water is still being made today. It is so large that it makes enough water every day to fill Earth’s oceans 60 times. All of this water, and the other molecules made in these star factories becomes part of new planets. On 22 July 2011, scientists found a gigantic cloud of water vapor that had 140 trillion times more water than the Earth's oceans combined around a quasar 12 billion light years from Earth. According to the researchers, the discovery shows that water has been in the universe for a very long time.
To find water in space, scientists make use of various tools and techniques. Telescopes with spectrometers can study the light coming from far away objects. Every molecule absorbs and emits light at specific wavelengths. By studying them, scientists can figure out whether there is water. Radio telescopes on the ground and space telescopes like the Hubble Space Telescope, the James Webb Space Telescope, and the Herschel Space Observatory have all helped us find water across the universe. In our own solar system, spacecraft missions have also been very important. NASA’s Galileo and Cassini missions found strong evidence of subsurface oceans on Jupiter's and Saturn’s moons. Cassini found geysers on Enceladus, with water vapor and ice particles erupting from the moon’s surface. On Mars, orbiters and rovers have found polar ice caps and certain rocks, which suggests that Mars might have had water in the past.
 In the solar system 
Water can be found in many places in our Solar System. Earth is the only planet we know of that has liquid water on its surface all the time. Water can be found as: solid (ice), liquid (water), and gas (water vapor) on Earth. Scientists have found tiny amounts of water vapor in the Sun’s atmosphere. The Sun is very hot. Its surface is about 5,500°C (9,932°F) and the inside is even hotter. Normally, water breaks down into hydrogen and oxygen in such heat. But there are cooler spots on the Sun, like sunspots. At sunspots, temperatures can drop to about 3,000°C (5,432°F). That is still very hot, but cool enough for water molecules to form for a short time before they break apart into hydrogen and oxygen again.
The Moon and Mercury both have water ice hidden in craters near their poles. These craters are always in the dark and never get sunlight. Because of this, the ice has stayed frozen for billions of years. NASA spacecrafts, like the Lunar Reconnaissance Orbiter and MESSENGER, have found that these ice do exist. Venus has water vapor in its atmosphere, just like Earth. But its surface is very hot and harsh. This means it does not have any liquid water on its surface. Scientists think Venus may have had water in the past, but it was lost into space. This is because Venus does not have a magnetic field to protect it like Earth does. Mars has ice caps at its poles made of water and carbon dioxide. There is also ice under the ground in many places. Rovers and orbiters have also found hydrated minerals. This means that liquid water once flowed on the surface of Mars a long time ago.
Asteroids are found near a part of the solar system called the “frost line”. This is the distance from the Sun where it is cold enough for water to freeze into ice. Beyond this line, you usually won't find liquid water because it is very cold. It can only be found hidden under ice, mixed with salt that keep it from freezing, or trapped under pressure in an atmosphere. One example is Ceres, a dwarf planet. It may have a layer of dust and rock on the outside, with salty water ice deep under the surface. Asteroids were once thought to be dry, but now scientists have found some that contain water ice or hydrated minerals. NASA’s OSIRIS-REx mission is helping us learn more about how much water some asteroids might have. Comets are pieces of ice leftover from the early solar system. They have a lot of frozen water. When a comet gets close to the Sun, the ice turns into gas, creating the famous glowing tails. There also exists a massive cloud of comets called the Oort cloud at the edge of the solar system.
The outer planets, Jupiter, Saturn, Uranus, and Neptune also have water. They are big gas giants or ice giants. They do not have a solid surface to walk on like our planet. Jupiter has water vapor in its thick atmosphere, but it is hard to see because of all the clouds. Saturn is like Jupiter. It has some water vapor in its atmosphere. Its beautiful rings are mostly made of water ice. Uranus might have an icy layer deep under its atmosphere. Neptune is similar to Uranus. Scientists think it also has an icy layer under its atmosphere that may contain water and other ices.
Some of the moons around the giant planets in our Solar System may have huge oceans of liquid water under their frozen surfaces. Europa, Ganymede, and Callisto, which orbit Jupiter, and Enceladus, and Titan, which orbit Saturn, might have underground oceans. Enceladus, a small moon of Saturn, shoots out jets of water vapor and ice from its south pole. A spacecraft named Cassini flew through these jets and found water, salts, and simple organic molecules. These are clues that there might be a hidden ocean with life. Titan, Saturn’s biggest moon, has lakes and seas on its surface, but they are filled with liquid methane and ethane, not water. Scientists think Titan has a salty water ocean deep underground, hidden under its icy surface. The moons of Uranus also have icy surfaces. Titania, the largest, has water ice and carbon dioxide ice. There might be liquid water under its surface. Triton, Neptune’s biggest moon, has a surface of frozen water ice. Deep under that ice, scientists also think it might have a liquid ocean.
The dwarf planet Pluto has a surface covered in frozen nitrogen and water ice. Pluto is extremely cold and far from the Sun. Scientists think Pluto might have a liquid ocean deep beneath its icy crust, about 100 kilometers deep. Pluto’s biggest moon, Charon, also has water ice. Beneath the surface, Charon may have had liquid water in the past. Some scientists think ice geysers might still happen on Charon.
 In interstellar space 
Water is not only found on planets and moons. It can also be found in the vast spaces between stars, the interstellar medium. The interstellar medium (ISM), is the scattered mix of gas, dust and radiation that can be found in the space between the stars in a galaxy. Water can be mainly found as ice covering dust grains in the interstellar medium and dense molecular clouds, where new stars are born. It can also be found as water vapor inside dense molecular clouds. In the coldest parts of the ISM, water molecules condense onto the surfaces of dust grains, forming icy mantles. These icy grains are very important ingredients in the chemistry of making stars and planets.
Molecular clouds, places where stars and planets are born, contain huge amounts of water. Water vapor has been found in many of these clouds, especially near newly forming stars. As young stars fuse hydrogen into helium they release heat around them. This warms up the surrounding ices, turning them into water vapor. This allows them to be observed by space telescopes such as the Herschel Space Observatory and the Spitzer Space Telescope. One of the most famous places where water has been studied is the Orion Nebula. Here, astronomers have found huge amounts of water vapor surrounding stars being born. In these environments, water is also very important in the chemistry that creates more complex organic molecules like amino acids. The Rho Ophiuchi cloud complex is a nearby molecular cloud about 460 light-years away. It contains protostars surrounded by water-rich ices. The ice in this region has been found using telescopes like Spitzer and JWST.
Ice and tiny grains of dust were the main ingredients that came together to form the Solar System. Scientists believe that the water in the solar system formed in space before our Sun or planets even existed. When star systems begin to form, gravity pulls together this gas and dust to make stars and planets. The dust already has water on it, which can become part of the new planets. That means planets like Earth might have been born with water already inside them.
 On exoplanets 
When looking for life on other planets, called exoplanets, water is one of the most important molecules scientists look for on other planets. We cannot use a telescope to look into other planets for water because they are very far away. But, astronomers have found others ways to look for water on some of these far away planets. The main way scientists study planets outside our Solar System is through something called transit spectroscopy. This means watching a planet as it passes in front of its star. When it does, some of the star’s light goes through the planet’s atmosphere to us. Depending on what the atmosphere is made of, certain parts of the light get blocked or bent. This creates a kind of “fingerprint” in the light that scientists can study. By looking closely, they can figure out which gases are in the atmosphere, like water or methane. Right now, studying the atmospheres of exoplanets is still very hard. Our tools are not perfect for this yet and it takes very careful measurements.
This method has found water vapor on many "hot Jupiters", such as HD 189733 b and HD 209458 b. These are large gas giants very close to their stars. Though these planets are far too hot for liquid water. Water exists as water vapor in the atmospheres of these planets. In recent years, telescopes have begun finding signs of water on smaller planets, especially sub-Neptunes and super-Earths. These are planets smaller than gas giants but larger than the Earth. One example is K2-18b, a super-Earth found by NASA's Kepler spacecraft in 2015. It is a planet with eight times the mass of the Earth that orbits a so called red dwarf star, which is much cooler than the sun. K2-18b can be found in the “habitable zone” of its star. This means it has the right temperature to have liquid water. Given its mass and radius, K2-18 b may either be a rocky planet with a thick atmosphere or be more like Neptune. Observations with Hubble and the James Webb Space Telescope (JWST) have found water vapor in its atmosphere. Though scientists cannot say if it has clouds, oceans, or even rain. Planets in the habitable zone, are places scientists are looking with new technology like the James Webb Space Telescope.
 The search for extraterrestrial life 
When scientists look for life in space, they often start by looking for water. Every living thing on Earth needs water to survive. Water has special chemical properties that make it perfect for life. It is really good at dissolving other substances, which helps living things carry out chemical reactions. Water stays liquid over a wide range of temperatures. It can help keep living organisms from getting too hot or cold. It also helps move nutrients and waste in and out of cells and living organisms. That is why scientists often say “follow the water” when searching for life beyond Earth.
Scientists think moons like Europa (which orbits Jupiter) and Enceladus (which orbits Saturn) might be able to have life. Both moons have thick layers of ice on their surface. Under that ice, scientists believe there are massive oceans of liquid water. The bottom of these oceans could be like hydrothermal environments found in the deep sea on Earth. On our planet, hydrothermal vents release hot, mineral-rich water from under the seabed. This creates a place where life thrives without sunlight. Instead of using sunlight for energy (like plants do), the organisms living there use chemical energy from the minerals in the water. This is a process called chemosynthesis. If similar hydrothermal vents exist on Europa or Enceladus, they could provide the energy and nutrients needed for life to survive in complete darkness, just like Earth’s deep sea life. Scientists have already found clues supporting these ideas. On Enceladus, for example, NASA’s Cassini spacecraft found jets of water vapor, ice particles, and organic molecules shooting out from cracks from the moon. This is a strong sign that there is liquid water and hydrothermal vents under its icy surface. These discoveries make Europa and Enceladus key targets for future space missions.
Mars remains a key target in the search for life beyond Earth. Although the planet is cold and dry today, it shows strong signs that it might have had water in the past. Ancient river valleys, dry lake beds, and minerals that only form in water suggest that liquid water once flowed on the Martian surface. Scientists believe that billions of years ago, Mars may have had a thicker atmosphere and a milder climate, possibly making it a habitable world. Even now, there may be salty liquid water hidden underground, especially near the poles or beneath the surface. Briny water, which contains dissolved salts, can stay liquid at colder temperatures, increasing the chances that it might still exist on Mars. To explore this possibility, NASA and other space agencies have sent robotic missions like the Perseverance and Curiosity rovers to study Mars up close. These rovers have advanced tools to analyze rocks, soil, and even the atmosphere. They are looking for biosignatures, which are chemical or physical signs that could suggest past life.
Scientists often look for water when they search for life on exoplanets. And they often look for planets in the habitable zone. This is the area around a star where temperatures are just right for liquid water to exist on a planet. If a planet is too close to its star, it will be too hot and water will boil away. If it is too far, it will be too cold and water will freeze. But in the habitable zone, things can be just right for water to stay liquid. Earth can be found in the habitable zone of the Sun. This is one reason it has oceans, rivers, and rain. That is why it can support so many kinds of life. When scientists study planets around other stars (called exoplanets), they look to see if those planets are also in the habitable zone. If they are, and they have the right kind of atmosphere, they might have water. And, they might even have life. Beyond our solar system, astronomers have discovered water vapor in the atmospheres of some exoplanets. These findings suggest that water, a key ingredient for life as we know it, might be common in the universe. This ongoing research brings us closer to answering one of the biggest questions in science: Are we alone in the universe?
 Uses of water 
Plants and animals (including people) are mostly water inside, and must drink water to live. It gives a medium for chemical reactions to take place, and is the main part of blood. It keeps the body temperature the same by sweating from the skin. Water helps blood carry nutrients from the stomach to all parts of the body to keep the body alive. Water also helps the blood carry oxygen from the lungs to the body. Saliva, which helps animals and people digest food, is mostly water. Water helps make urine. Urine helps remove bad chemicals from the body. The human body is between 60% and 70% water, but this value differs with age; i.e. a foetus is 95% water inside.
Water is the main component of drinks like milk, juice, and wine. Each type of drink also has other things that add flavor or nutrients, things like sugar, fruit, and sometimes alcohol. Water that a person can drink is called "potable water" (or "drinking water"). The water in oceans is salt water, but lakes and rivers usually have unsalted water. Only about 3% of all the water on earth is fresh water. The rest is salt water.
Many places, including cities and deserts, don't have as much water as people want. They build aqueducts to bring water there.
Though people can survive a few months without food, they can only survive for a day or two without water. A few desert animals can get enough water from their food, but the others must drink.
Water has no smell, taste, or color.
Water is also used for recreational purposes, see list of water sports.
Water is used as both the coolant and the neutron moderator in most nuclear reactors. This may be ordinary water (called light water in the nuclear industry) or heavy water.
Water is also used for washing a lot of objects. Goods, services and people are transported to other countries in watercrafts on bodies of water.
Water is used in chemical reactions as a solvent or reactant. Water is also used in fire fighting. Water is also used for cooking.
 Water laws, crisis, and geopolitics 
 Water laws 
Water laws are rules that help decide how water is shared, used, and protected. These laws are important because water is something that everyone needs. People, farms, businesses, and nature all depend on water. Water laws help figure out who can use water, how much they can use, and what they can use it for. They also try to make sure that water is used fairly and not wasted or polluted. In many places, water is limited, and if it is not managed well, it can run out or get too dirty to use. Water laws are meant to stop problems like this including fights over water. They also help make sure there is enough clean water for things like drinking, growing food, making energy, and protecting the environment.
Water rights are the rules about who can use water and how much they can use. These rules are part of water laws. There are different kinds of water rights depending on where you live and the laws people follow. One common system is called riparian rights, which is often used in places with plenty of water. With riparian rights, if you own land next to a river, lake, or stream, you have the right to use the water. But you have to be careful not to harm the people who live downstream. In drier places, they often use a different system called prior appropriation. This follows the rule of "first in time, first in right." The first person to take water for a useful purpose has the right to keep using it, even if their land is not next to the water. In many parts of the world, especially in rural or indigenous communities, customary or traditional laws also guide how water is shared. These laws are based on old practices and cultural values that help people respect and protect water. Different countries have their own laws and rules for managing water. Some countries focus on deciding who can use water and how they can use it, while others pay more attention to stopping pollution or building things like dams and pipelines to help control water. When rivers, lakes, or underground water cross borders between countries, water law becomes more complicated. In these cases, countries need to work together and make agreements to share the water fairly and avoid fights. For example, many countries share big rivers like the Nile, Mekong, and Danube. These countries cooperate through special agreements to manage the water in a way that works for everyone.
Water use is usually managed by national or local governments and special government agencies. These groups decide how much water people can use, check that the water is clean and safe, and protect the plants and animals that need water to live. They also help solve problems when two communities or businesses want to use the same water source. Water governance means making sure water systems are cared for, pollution is controlled. It also means making sure everyone has access to clean water for drinking and hygiene. Good water management is very important to handle problems like droughts, floods, growing populations, and climate change. There are many important examples of water laws and how they affect people. In the United States, the Clean Water Act is a big law that helps protect rivers, lakes, and other water from pollution. In Africa, the countries along the Nile River have talked and sometimes argued for a long time about how to share the river’s water fairly. Some countries are starting to say that water is a public good or even a human right. This means that everyone should be able to get clean water, no matter how much money they have or who they are.
 Water crisis 
A water crisis is a serious situation that happens when people do not have enough clean and safe water to meet their daily needs for drinking, cooking, washing, and farming. It also includes times when water is available but too polluted or too far away to be used safely. A water crisis can also affect the environment. It can harm rivers, lakes, and plants and animals that depend on water. This problem is not just about having no water at all. It also includes having water that is too dirty, too expensive, or too difficult to reach. There are many reasons why water crises happen.
One major cause is population growth. As more people are born and the world’s population grows, more clean water is needed for drinking, cooking, washing, and growing food. As cities get bigger and more people use water, rivers, lakes, and underground water sources are being used up faster than nature can replace it. This causes a water scarcity, which means there is not enough clean water for everyone’s needs. In big cities, the problem can get worse. When lots of people live close together, they all need water at the same time. In poor neighborhoods or fast-growing areas, some people may not have any clean running water at all. In the countryside, farmers use a lot of water to grow crops and feed animals. As the population grows, the demand for food grows too, so farmers need even more water. Some use strong pumps to pull water from underground, but if they take too much, the water underground can run out.
Another big problem is pollution. Even though there is water in rivers, lakes, and oceans, a lot of it is not safe to drink or use because it is polluted. Pollution happens when harmful things like chemicals, trash, or dirty water from homes and factories get into natural water sources. This makes the water dangerous for people, animals, and plants. One major source of pollution is waste from homes and cities. When people wash dishes, take showers, or flush toilets, that dirty water has to go somewhere. In some cities, it goes to special treatment plants that clean the water. But in many places around the world, there are no good systems, so the dirty water goes straight into rivers or lakes. This can carry germs that cause serious diseases like cholera or diarrhea. Even in big cities, if the water system breaks or gets too full during a storm, dirty water can mix with clean water and make it unsafe to drink. Factories and farms also cause a lot of water pollution. Some factories dump leftover chemicals, oil, or heavy metals into nearby rivers to save money. These dangerous substances poison the water and can build up in fish, making them unsafe to eat. On farms, people use fertilizers and pesticides to help crops grow and kill bugs. But when it rains, these chemicals can wash off the land into rivers or lakes. This is called “water runoff.” It can make algae grow too fast. When the algae die, they use up the oxygen in the water. Then fish and other animals cannot survive, and parts of the water become “dead zones” where nothing can live. Plastic is another big problem. Every year, tons of plastic bottles, bags, and wrappers end up in rivers and oceans. Plastic does not break down easily, so it can float in the water for years. Sea animals like turtles or fish might eat plastic by mistake and die. Tiny pieces of plastic, called microplastics, have even been found in drinking water and seafood. Scientists are still studying how these microplastics might affect human health.
Another big reason for water problems is overuse. This means people are using too much water too fast, much faster than nature can refill it. Every day, water is needed for many things like drinking, cooking, cleaning, farming, making clothes, building houses, and running factories. As more people live on Earth, they use more water. But there is only a limited amount of fresh water on the planet. When we take too much water without giving nature enough time to replace it, rivers dry up, lakes get smaller, and underground water sources called aquifers drop lower and lower. Farming uses the most water of all. Farmers need water to grow crops and take care of animals, but in many places, they use more water than necessary. Sometimes they flood their fields, and a lot of the water is wasted or lost to evaporation. In dry places, farmers often pump water from deep underground. At first, this works well, but if they keep pumping too much, those underground water supplies start to run out. Once an aquifer is empty, it can take many years or even centuries to fill up again. This is happening in parts of the United States, India, China, and many other countries. Factories and industries also use huge amounts of water to make things like paper, steel, clothes, and electronics. For example, it takes thousands of liters of water to make just one pair of jeans or a hamburger.
Another big reason for the water crisis is poor infrastructure. Infrastructure means the systems and buildings we use to carry, store, clean, and deliver water, like pipes, pumps, water treatment plants, and storage tanks. In many places, especially in poorer countries or old cities, these systems are old, broken, or not built well. This means that even if there is enough water nearby, people still cannot get clean, safe water in their homes. Because of this, millions of people either get no water at all or have to use water that can make them sick. In some poor or rural areas, there might be no water system at all, so people have to walk long distances to rivers or wells to get water by hand. Sometimes this water is not clean because there is no way to filter or clean it. In cities, even when pipes and pumps exist, they may be old and not well cared for. Leaking pipes waste a lot of water, sometimes up to half of it is lost before it even gets to homes or schools. In crowded neighborhoods, especially slums, water pipes may only work a few hours a day or not at all. People there have to buy water from trucks or use unsafe sources. Water treatment plants are supposed to clean the water by removing dirt, germs, and chemicals before people drink it. But if these plants are too small, do not have enough money, or are broken, the water from taps can still be unsafe. Dirty water can cause diseases like cholera, typhoid, and diarrhea, which kill thousands of people every year, especially children. Sometimes, clean water and dirty sewage use the same underground pipes. When those pipes break or flood, the two can mix, making people sick without them knowing. As more people move to cities, they need more water, but water systems do not always grow fast enough to keep up. During heat waves or droughts, the systems can break down even more. And during floods, water pipes may burst or get clogged, leaving people without water for days.
Another big reason the world has a water crisis is that governments often do not manage water well. Even if a country has enough water, bad planning, weak laws, and unfair choices can cause big problems. In many places, water is not shared fairly. Some people, especially those in rich neighborhoods or powerful companies, get plenty of clean water, while others in poor areas get very little or none at all. Sometimes governments build big water projects like dams or canals, but these only help a few people and leave out whole communities. Poor water planning also causes waste and shortages. In some countries, water is used without limits. Big farms or factories take as much water as they want from rivers or underground, and the government does not keep track of it. This causes overuse, where water is taken faster than nature can replace it. Also, water bills may be too cheap or not collected at all, so people do not try to save water. In other places, governments do not spend enough money on water systems, so pipes leak, treatment plants break, and many areas have no working water services. Sometimes, powerful people or companies bribe officials to get more water than they need, while others are ignored. Governments may promise to build water projects but never finish them, or the money disappears because of corruption. Sometimes leaders make decisions without asking local people what they really need, so water projects do not fix real problems. For example, a city might build a big water pipeline but forget to build toilets or drains, which can cause health problems. Another issue is that many governments do not plan for the future. As cities grow and the climate changes, water needs change too. But without good planning, old water systems cannot keep up. When droughts happen, there are no backup plans. When floods come, water systems break down.
At the same time, climate change is making the water problem worse. As the Earth gets hotter, it changes how water moves in nature. Normally, water falls as rain or snow, flows into rivers and lakes, and then evaporates back into the air. But with climate change, this natural water cycle gets out of balance. In many places, rain does not come when it is needed, or it falls all at once in heavy storms that cause floods. Some areas are getting drier, while others get too much water. This makes it harder for people to get clean and steady water when they really need it. In dry places, climate change causes droughts to happen more often and last longer. A drought is when there is very little rain for a long time. This causes rivers to shrink and lakes to dry up. Crops would not grow, and animals would not have enough water to drink. Farmers suffer the most because they need water to grow food and take care of their families. On the other hand, some places get too much water at once. Heavy rain from warmer temperatures can cause floods that destroy homes, farms, and water systems. Flood water can mix with sewage and chemicals, making it dirty and unsafe to drink. Even though floods bring lots of water, it is often not clean or useful. Also, glaciers and snowpacks in mountains are melting faster than before. These usually act like natural water tanks, slowly releasing water during dry months. But now, they are disappearing, which means millions of people who live downstream will have less water in the future.
The world is facing a very serious water crisis, and the numbers show how big the problem really is. Right now, more than 2.2 billion people, almost 1 out of every 4 people on Earth, do not have safe drinking water at home. That means they cannot just turn on a tap to get clean water to drink, cook, or wash with. Even more people, about 3.5 billion, do not have proper sanitation, like toilets or safe ways to get rid of dirty water. Without clean water and safe toilets, diseases spread easily, and many children, especially in poor areas, get sick. According to the World Health Organization, around 500,000 people die every year from diseases caused by dirty water and poor hygiene. About 4 billion people, more than half the world’s population, face serious water shortages for at least one month every year. Some of the countries with the worst water problems include India, Egypt, Iran, and parts of the United States, like California. In these places, rivers are drying up, underground water is running low, and lakes are shrinking. For example, the Aral Sea, which used to be one of the largest lakes in the world, has almost completely dried up because people used too much of its water. In Cape Town, South Africa, the city almost ran out of water in 2018. The crisis was so bad they called it “Day Zero,” the day the taps would be turned off if water ran out. Climate change is making things worse. As the planet gets hotter, droughts are happening more often and lasting longer. Rain patterns are changing, so some places get too much rain all at once, causing floods, while other places don't get enough rain, leading to dry land and crop failures. The United Nations says that by 2050, over 4 billion people might not have safe water at home unless we make big changes. Even in places that have enough water, the systems that deliver it do not always work well. The World Bank says the world loses about $260 billion every year because of bad water systems, like leaking pipes, poor planning, or people getting sick and missing work or school because of waterborne diseases. At the same time, people living in slums or rural areas often have to pay more money per liter for water than rich people in cities. That is because they have to buy it from private sellers or carry it from far away. This is unfair and keeps many families stuck in poverty.
There are many ways we can fix the water crisis, but it takes everyone working together, including governments, businesses, communities, and ordinary people. One of the most important steps is to build and fix water systems. This means making sure pipes, pumps, treatment plants, and tanks work well and bring clean water to everyone who needs it. In many poor places, there are no water systems at all, so people have to walk far to get water. By investing in strong water systems, clean water can be delivered straight to homes, schools, and hospitals. Good systems also stop leaks, so less water is wasted before it even reaches people. Another important solution is to use water more carefully and waste less. Many people and factories use more water than they really need. Simple things like fixing dripping taps, taking shorter showers, and turning off the water while brushing your teeth can save a lot of water. Farmers, who use most of the world’s water, can use better methods like drip irrigation and collecting rainwater to grow crops with less water. In cities, recycling water from sinks and showers to flush toilets or water plants helps save even more. Protecting and cleaning our water sources is also very important. Rivers, lakes, and underground water can get polluted by trash, chemicals, and sewage. To keep water clean, we need to stop dumping waste into nature. Governments should make strong laws to control pollution from factories and farms. People can help too by not throwing garbage into rivers or drains, and by using less plastic and fewer harmful cleaning products. Fair government rules are needed as well. In some places, water is not shared fairly. Rich neighborhoods and big companies get plenty of water, while poor communities get very little. Governments must treat water as a basic human right, not just something to buy and sell. They should plan for the future by knowing how much water is available, who needs it most, and how to protect it from climate change. They should also include local people when making decisions about water use and sharing. Education is another important part of solving the water crisis. Many people do not know how serious the problem is or what they can do to help. Schools, TV shows, and community projects can teach kids and adults about water and why it's important to save it. Finally, technology can help a lot. New tools like water filters, low-water toilets, smart irrigation systems, and apps that track water use make saving water easier. Even simple tools like tanks that collect rainwater from rooftops can give families clean water in dry areas. Scientists and engineers are working on ways to clean salty ocean water, safely recycle wastewater, and watch water use from space. All these ideas together can help make sure there is enough clean water for everyone.
 Water geopolitics 
Water is one of the most important resources on Earth. People need it to drink, cook, clean, and grow food. But when there is not enough water, or when it is not shared fairly, it can lead to conflict between people, groups, or even countries. One major cause of water conflict is scarcity. Scarcity means there is not enough water for everyone who needs it. This can happen in dry places where it does not rain much, or in areas where the population is growing quickly and using too much water. When water is limited, people may start to argue or fight over who gets to use it. For example, if two farmers both use the same river to water their crops, but the river starts to dry up, they may blame each other and argue about who should get more water. These kinds of problems can happen between neighborhoods, cities, or even whole countries that share rivers or lakes.
Another reason people fight over water is when rivers or lakes cross borders between countries. These are called transboundary water sources, and they can cause serious problems. For example, the Nile River flows through several countries in Africa. Each country wants to use the water for things like farming and electricity. If one country builds a dam or takes more water than before, the others may get upset or worried they would not have enough. The same kind of conflict happens in other parts of the world. India and Pakistan have had disagreements over the Indus River, and countries in Central Asia have argued over rivers that come from melting mountain glaciers. If countries do not find fair ways to share the water, it can lead to political fights and even war. Pollution is another cause of water conflict. When factories, farms, or cities dump waste into rivers or lakes, the water becomes dirty and unsafe. If one group pollutes the water and another group depends on it for drinking or farming, big problems can happen. People downstream may get sick or lose their crops and blame those upstream. This can lead to lawsuits, protests, or even violence. Even within one country, different areas or groups might argue about who is polluting the water and who should pay to clean it up. These fights can make it even harder to solve the water crisis.
Unfair sharing of water can also cause problems. In many places, rich neighborhoods or big companies get more water than poor communities. When there is not enough water for everyone, and some people have plenty while others have none, it can make people upset and angry. This can lead to protests or even fights. For example, in some cities, poor areas called slums may have no running water at all. But at the same time, fancy hotels nearby might use a lot of water to fill swimming pools or run fountains. When people see this kind of unfairness, they may feel they are being treated badly and demand change. Climate change is also making water conflicts worse. As the Earth gets hotter and rain becomes less regular, droughts are happening more often. This puts more stress on water supplies and makes people compete even more. In some places, climate change is melting glaciers and drying up rivers. When water becomes harder to find, people worry more and fight harder over the little that is left. If governments do not step in to share water fairly and plan for the future, these conflicts could become more serious over time.
One of the most well-known water conflicts in the world is happening along the Nile River in Africa. The Nile is the longest river in the world, and it flows through 11 different countries, including Ethiopia, Sudan, South Sudan, Egypt, and Uganda. This river is very important because millions of people use it every day for drinking water, farming, fishing, and making electricity. But since so many countries share the Nile, there are many disagreements about how the water should be divided. The biggest conflict is between Ethiopia, Sudan, and Egypt. Each country depends on the Nile for different reasons, and they do not always agree on what is fair. A major reason for the conflict is a huge dam that Ethiopia is building. It is called the Grand Ethiopian Renaissance Dam, or GERD. Ethiopia started building this dam in 2011 on the Blue Nile, one of the two main branches of the Nile River. Ethiopia says the dam is important because it will create electricity for millions of people who do not have enough power. They believe it will help the country grow and develop. However, Egypt is very worried about the dam. Egypt gets about 90% of its water from the Nile, and it fears the dam will lower the amount of water flowing to its farms and cities. Egypt needs the Nile for almost everything, especially to grow crops in the desert. Sudan is in the middle. On one hand, the dam could help Sudan by reducing floods and giving them more electricity. On the other hand, Sudan is worried that Ethiopia might fill the dam too quickly, which could reduce the amount of water Sudan receives for farming and drinking. Sudan wants all three countries to make a clear agreement so that everyone can benefit and no one gets harmed. Ethiopia, Egypt, and Sudan have been talking about this issue for many years, but they still have not made a final deal. Egypt wants strict rules about how and when Ethiopia can fill the dam, especially during dry years. Ethiopia wants to control the dam itself and believes it has the right to use the river that starts in its land. Because of these disagreements, there have been many arguments, tense meetings, and even threats. Some people worry that if the countries cannot work together, it could lead to a serious crisis or even conflict.
Another example of water conflict is between India and Pakistan. These two countries have not always gotten along, and sharing water has made things even more difficult. The Indus River and its smaller rivers start in India but flow into Pakistan. In 1960, the two countries signed a water treaty to divide the rivers fairly. But even today, each country is worried that the other might take more water than they should. When India builds new dams or water projects, Pakistan gets alarmed and accuses India of breaking the agreement. These water issues add to the already tense relationship between the two countries. In the Middle East, water is very limited, and this leads to many conflicts. One example is the Jordan River, which flows through Israel, Jordan, and Palestine. All three groups need the river for drinking water, farming, and everyday life. But over the years, the river has shrunk because of overuse and pollution. As the water supply drops, arguments have grown. In the West Bank, many Palestinian communities struggle to get enough water, while nearby Israeli settlements often have steady supplies. This unfair access makes people angry and adds to the political tension. Some efforts have been made to share the water more fairly, but it is hard because the groups do not trust each other. In Yemen, a country dealing with war and poverty, water shortages have also led to conflict. Many people there do not have clean water. As wells dry up, villages and tribes sometimes fight over who gets to use the last water sources. In some rural areas, armed groups have taken control of water supplies, making it even harder for families to get the water they need. Some experts believe that water problems have made Yemen’s civil war even worse. This shows how lack of water can become even more dangerous when a country is already in crisis.
In the United States, water conflicts happen more often than people might think, especially in the western part of the country where water is harder to find. One of the biggest and most well-known water fights is over the Colorado River. This river flows through seven states: Colorado, Wyoming, Utah, New Mexico, Arizona, Nevada, and California. It also flows into Mexico. More than 40 million people use the Colorado River for drinking water, farming, and making electricity. But lately, the river has been shrinking because of drought, climate change, and using too much water. The states argue over how much water each one should get. For example, California uses a lot of water for growing food in the desert, while big cities like Las Vegas and Phoenix need more water as more people move there. The government has tried to help the states make fair deals, but it’s been very hard to agree on a long-term solution. Another big water conflict in the U.S. is between Georgia, Alabama, and Florida. This fight has been going on for decades. These states share rivers like the Chattahoochee and the Flint, which come together to form the Apalachicola River. Georgia wants more water for the city of Atlanta and for farms. But Alabama and Florida say that if Georgia takes too much water, there would not be enough left for them. Florida especially needs the water to keep its seafood industry alive in Apalachicola Bay. This fight has gone all the way to the U.S. Supreme Court, but even after many years, it is still not solved. Even in places with more water, like around the Great Lakes, there can still be conflicts. Some towns and companies want to take more water out of the lakes for their own use, but others worry this could hurt the environment or lower the water levels. The Great Lakes are shared by several U.S. states and Canada, so any plan to use the water has to be agreed on by everyone. In 2008, a deal called the Great Lakes Compact was made to protect the lakes and stop people from taking water unfairly. Still, some places try to find ways around the rules, which causes more arguments and concern.
Even though water can sometimes cause conflict, it can also help bring people together. Many countries, states, and communities have worked hard to cooperate and make fair deals about how to share water. These water agreements are very important because they help prevent arguments, protect nature, and make sure everyone has the water they need. When countries share rivers, lakes, or underground water, they often create treaties, or written agreements. These treaties explain how much water each side can use and what to do if there is a problem. They might also include plans to keep the water clean and to stop pollution and waste. One famous example is the Indus Waters Treaty between India and Pakistan. This treaty was signed in 1960 with help from the World Bank. The Indus River system flows through both countries and is very important for farming and daily life. Even though India and Pakistan have had many political problems and even wars, this water treaty has mostly worked well. It divides the rivers between the two countries and includes rules about building dams and using the water fairly. The treaty has helped stop big water fights for over 60 years. This shows that even countries that do not get along can work together when it comes to water.
Another important example of water cooperation is the Senegal River Basin agreement in West Africa. The Senegal River flows through several countries, including Senegal, Mali, and Mauritania. In 1972, these countries created a group called the Organisation for the Development of the Senegal River (OMVS). They agreed to manage the river together, share the water fairly, and build dams and power plants that help all the countries. The group listens to farmers, fishermen, and local leaders to make sure everyone’s needs are heard. This kind of teamwork helps people trust each other and solve problems peacefully. In Europe, there are many rivers that cross between countries. One of the most important is the Danube River, which flows through more than 10 countries. In 1994, these countries signed the Danube River Protection Convention. They promised to work together to keep the river clean, prevent floods, and protect the plants and animals that live in and around the water. The agreement includes regular meetings, water testing, and teamwork during emergencies. Because of this, the Danube remains safe and helpful for millions of people. The United Nations (UN) also supports water cooperation around the world. In 1997, the UN created a special agreement called the Convention on the Law of the Non-Navigational Uses of International Watercourses. This set of rules encourages countries to share water fairly, avoid harming each other, and settle arguments peacefully. Not all countries have signed it, but it still helps guide how nations work together to manage shared rivers and lakes. The UN also celebrates World Water Day every year on March 22 to remind everyone how important it is to work together on water issues.
 In culture 
 In religion 
Water has deep meaning in many cultures and religions around the world. Almost everywhere, water is seen as a symbol of purity, life, and change. It often stands for cleansing, not just of the body but also of the spirit. People believe water can wash away bad things and help start fresh. It is important to many religious beliefs and spiritual practices. It can represent the cycle of life, rebirth, and the connection between the physical world and something sacred or divine. In many faiths, water is used in religious rituals to bless or purify people. These ceremonies include baptisms, ritual washings, and blessings. For example, people may wash their hands, face, or whole body before prayer or entering a sacred place to show respect and prepare for spiritual contact. In baptism, a person is dipped in or sprinkled with water to mark the start of a spiritual journey. It often means the washing away of sins and beginning a new life. Water may also be sprinkled or offered during other ceremonies to bless people, objects, or spaces. These practices show the belief that water has spiritual power.
Different religions use water in special ways. In Christianity, baptism is an important ceremony where water is used to show spiritual cleansing and a new life in Jesus Christ. In Islam, water is used in wudu (a small washing) and ghusl (a full-body washing). These are done before prayers and other holy activities to be clean in body and spirit. In Hinduism, water is very sacred, especially rivers like the Ganges. People believe this river can wash away sins. It is used in many ceremonies, including funerals. Buddhists use water in temple rituals as a sign of offering and for spiritual cleansing. In Judaism, there is a special bath called a mikveh. People use it for purification during important times, like before getting married or when entering the religion. In Sikhism, being clean is part of being spiritual. Sikhs use water for bathing and in some religious rituals. Many indigenous and animist traditions also see water as sacred. Rivers, lakes, and springs are believed to be the homes of spirits or gods. They are often part of rituals and traditional stories.
Sacred water sources are very important in many religions. People often travel long distances to visit these special places during pilgrimages. These water sites are believed to have healing powers or a spiritual presence. For example, in Christianity, many people visit the spring at Lourdes in France, which is believed to heal the sick. Every year, millions of people go there to pray and collect water. In Hinduism, the Ganges River is one of the most holy rivers. Bathing in it is believed to wash away sins and bring blessings. In Islam, the Zamzam Well in Mecca is a sacred part of the Hajj pilgrimage. It has deep spiritual and historical meaning for Muslims.
 In philosophy 
In ancient times, people believed that everything in the world was made from a few basic things called elements. One of the first known Western philosophers, Thales of Miletus, lived in the 6th century BCE and thought that water was the most important of them all. Thales believed that water was the origin of everything. He called it the "archê," a Greek word that means "first principle" or "beginning." He noticed that water is essential for life and can exist in three forms: solid, liquid, and gas. Because of this, he thought water was the basic building block of the universe. Thales was one of the first people to try to understand the world through observation and reason, instead of relying on myths or stories. His ideas helped start what we now call natural philosophy, the early form of science.
As philosophy grew in different parts of the world, many cultures gave water an important place in their way of thinking. In ancient Greece, famous philosophers like Plato and Aristotle believed that everything was made of four main elements: earth, air, fire, and water. Each element had special qualities. Water was thought to be cold and wet. It was linked to change and movement because of the way it flows. In Eastern philosophy, water also had deep meaning. In Daoism, a major tradition from China, water is a symbol of ideal behavior. It flows gently, adapts to its surroundings, and can slowly wear down even hard rock, not by force, but with patience and persistence. This idea is part of the Daoist teaching called wu wei, which means acting without effort or force. In Indian philosophy, water is one of the Pancha Mahabhuta, or five great elements, in both Hinduism and Buddhism. Water stands for emotion, cleansing, and flow. It is seen as important not just for the body, but also for the soul and the balance of nature.
Throughout history, philosophers have used water as a symbol or metaphor in their writing. Water is often used to represent the flow of time, the way we think and feel, or how things can change shape while staying as the same substance. In many traditions, water stands for change or transformation. It can turn into ice or steam, then go back to being liquid again. Because of this, philosophers use water to talk about how life is always changing, and how nothing stays the same forever. Water is also used to explain how our identity (who we are) is not fixed. Like water takes the shape of whatever container it is in, people can be shaped by their surroundings and experiences. In more recent times, philosophers still talk about water in many important ways. In ecological philosophy, they explore how people are connected to nature and the environment, and water is a big part of that. In existentialism, water can be a symbol for things like uncertainty, deep thoughts, or the search for meaning in life. In environmental ethics, water is often discussed in debates about natural rights, fairness, and how to protect the planet. Some modern philosophers believe that water should be seen not just as a resource we use, but as a living system that should be treated with respect and care. Others study how water affects people’s lives, culture, and identity. In a type of philosophy called phenomenology, which looks at how we experience the world, water might be studied through the senses. How it feels, looks, sounds, and moves.
 In folklore 
Water has been connected to mythical creatures and spirits in many cultures around the world. Stories often tell of beings like mermaids, nymphs, kelpies, nāgas, and other water spirits that live in rivers, lakes, or the ocean. These magical beings are sometimes seen as protectors of water. They might guard a water source and punish people who harm it. In other stories, they may try to trick or lure humans into the water. Some water spirits are wise and kind, offering help or magical advice. Others are tricksters or bring bad luck. In Japanese folklore, there is a creature called the kappa. Kappa are often seen as water spirits or kami in Japanese folklore. They can act in both mischievous and dangerous ways. Sometimes, they play pranks, like trying to peek under people's clothing near the water. But in other stories, they can be harmful, even trying to drown people or animals or scare children. Even though they can be scary, not all kappa are mean. Some are shown to be friendly and can even help humans. In Celtic legends, water fairies are magical beings that live in rivers, lakes, springs, and wells. They are often connected to nature. They are believed to guard the water and its power. These fairies can be kind and helpful, but they can also be tricky or dangerous if they are disrespected. In parts of Africa, people believe in Mami Wata, a powerful water spirit who can appear as a beautiful woman or a mermaid. She is seen as a guardian of rivers and oceans. Mami Wata protects the natural world. She can bring blessings to those who honor her. But if someone disrespects her, pollutes the water, or breaks a promise, she may punish them. In Greek mythology, sirens were dangerous creatures who lived on rocky islands in the sea. They looked like part woman and part bird, but later stories showed them to be more like mermaids. Sirens had beautiful voices and sang songs so sweet that sailors could not resist. The music would lure the sailors closer and closer until their ships crashed on the rocks.
In many myths and folktales, water is seen as a gateway or border between different worlds. Rivers, lakes, and oceans are often shown as dividing lines between the world of the living and the dead, or between the human world and the spirit world. In Greek mythology, there is a river called the Styx that separates the world of the living from the underworld. When someone dies, their soul must cross the river to reach the land of the dead. A boatman named Charon ferries the souls across, but only if they have a coin to pay him. In Celtic stories, lakes and misty waters are often seen as gateways to the Otherworld, a magical realm where spirits and fairies live. Some tales say that if you walk into the mist on a quiet lake, you might disappear into another world. The boundary between the worlds is thin near water, especially at dawn or dusk. In Japanese folklore, there is a belief that spirits of the dead must cross a river called the Sanzu River to reach the afterlife. Like the Greek Styx, it is a border between the living and the dead. Depending on how someone lived their life, they might cross on a bridge, wade through shallow water, or struggle through deep, rough currents. In some Native American traditions, water is a pathway between the physical world and the spirit world. Shamans or spiritual leaders may enter a trance near a river or waterfall to connect with spirits.
In many cultures, water plays an important role in myths about creation and destruction. In Babylonian mythology, the world began from a vast, dark ocean. Two great water beings, Apsu (fresh water) and Tiamat (salt water), came together to create the first gods. Later, Tiamat became angry and turned into a monster to destroy them. One of the gods, Marduk, defeated her and used her body to form the sky and the earth. In the Bible, there is the story of Noah's Ark, where God sends a great flood to destroy the world because of human wickedness. The floodwaters cover the earth, wiping out nearly everything. But after the water goes down, life begins again. In Hindu mythology, the god Vishnu rests on a cosmic ocean before the world is created. From his navel grows a lotus flower, and from that flower comes Brahma, the creator god. Later, when the world becomes evil, Vishnu sends great floods to destroy it and prepare for a new age. In Norse mythology, at the end of the world, called Ragnarök, giant waves and floods cover the earth as the sea serpent Jörmungandr rises from the ocean. Many gods die, and the world is destroyed in water and fire. But after the flood, the world slowly rises again, green and peaceful, ready for a new beginning.
In many myths and legends, water is linked to healing and change. People have long believed that special places like sacred springs, wells, and fountains have magical or healing powers. In these stories, someone who drinks the water or bathes in it might be cured of an illness, feel stronger, or even gain special abilities. In Celtic folklore, there are many stories about sacred wells and springs. These places were believed to be blessed by spirits or ancient gods. People would visit them to wash their wounds or drink the water, hoping to be healed. Some wells were also believed to grant visions or wisdom if the visitor was pure of heart. In Christian tradition, the waters of Lourdes in France are said to have healing powers. A young girl named Bernadette saw visions of the Virgin Mary near a spring. Since then, millions of people have traveled to Lourdes to bathe in the water or collect it, praying for cures to sickness or pain. In Japanese mythology, there are stories of people bathing in hot springs or sacred waterfalls to purify their bodies and spirits. These waters are connected to nature spirits called kami, and being near them can bring peace, health, and even a new beginning. In Greek myths, the fountain of youth or magical springs could restore a person’s youth and beauty. Heroes sometimes went on long journeys to find such water. One famous example is the River Lethe, where drinking the water caused people to forget their past, offering a kind of spiritual reset or rebirth.
 In art 
Water has been a powerful symbol in art for thousands of years. Artists use water to show many different feelings and ideas, such as peace, change, danger, or mystery. In paintings, water often appears as oceans, rivers, rain, or even tears. It can be calm and still, like a quiet lake, or wild and strong, like crashing waves. These images help people feel something when they look at the artwork. For example, a peaceful painting of a pond might make someone feel relaxed, while a stormy sea might show fear or struggle.
In many cultures, water is also used in art to show life and rebirth. In religious art, water is sometimes shown as holy, like in Christian paintings of baptisms, where water is used to wash away sins and begin a new life. In Hindu and Buddhist art, rivers like the Ganges are drawn or carved into temples to show purity and connection to the divine. In ancient times, water also appeared in art to show myths and legends. In Greek and Roman art, gods like Poseidon or Neptune were often shown holding tridents and riding waves or sea creatures. In Egyptian art, the Nile River was a symbol of life and was often painted in scenes of farming, fishing, and ceremonies.
One famous example of water in art is “The Great Wave off Kanagawa” by the Japanese artist Hokusai. This woodblock print shows a huge, powerful wave towering over small boats, with Mount Fuji in the background. The wave looks alive, with curling foam like claws, ready to crash down. Even though the image is full of movement and danger, it is also beautifully balanced and carefully designed. Hokusai may have used the sea not just to show nature’s power, but also the strength and struggle of people facing it. This artwork has become one of the most well-known in the world. Another famous painting that shows water is “Water Lilies” by the French artist Claude Monet. Monet painted many versions of this scene, showing a quiet pond with lily pads, flowers, and reflections of trees and sky on the surface of the water. The soft colors and blurred brushstrokes make the paintings feel peaceful and dreamlike. His paintings help people feel calm and connected to nature, like they are standing next to the pond themselves.
Artists also use water in more practical ways. Watercolor painting, for example, uses water to blend colors in soft, flowing shapes. This kind of painting is known for its light, dreamy look. It is perfect for painting things like clouds, rain, or gentle waves. Some modern artists even create art with water itself, such as fountains, pools, or water installations that change with movement and time. These works let people see, hear, and even touch the water, making the experience feel alive and special.
 In literature 
Water shows up in many stories, poems, and myths from all over the world. In books and other writing, water often stands for feelings, life, change, or the unknown. One well-known example is in the book The Old Man and the Sea by Ernest Hemingway. In this story, an old fisherman goes out into the ocean by himself and tries to catch a huge fish. The sea is more than just the place where the story happens. As the fisherman fights to catch the fish, the story talks about human strength, being alone, and having respect for nature. The water shows both danger and deep wisdom.
In Moby-Dick by Herman Melville, the ocean is a big part of the story. The book is about Captain Ahab and his crew as they sail across the sea to find a giant white whale named Moby Dick. The ocean is not just where the story takes place, it also stands for big ideas like the unknown, the power of nature, and life’s deepest questions. Captain Ahab becomes obsessed with hunting the whale, and this makes the sea feel dangerous and full of madness. In The Odyssey by Homer, water is a big part of the story. Odysseus, the main hero, spends many years sailing across the sea to get home after the Trojan War. Along the way, he faces storms, sea monsters, and powerful gods. Each time he travels by water, he faces new problems that test how brave and smart he is. The sea is more than just something to cross, it is a place of adventure, danger, and change. It helps Odysseus grow into a wiser and stronger person. This ancient story shows that water, especially the ocean, was seen as a powerful and magical force, full of meaning and mystery.
In The Secret Garden by Frances Hodgson Burnett, water is shown in a soft and peaceful way. There are moments when rain falls and helps bring the garden back to life. The rain makes the flowers grow and the air feel fresh and clean. For the characters in the story, hearing the rain and feeling the wet earth become signs that things are getting better. The water helps turn the garden from a quiet, lonely place into one that is full of beauty and happiness. In Huckleberry Finn by Mark Twain, the Mississippi River is very important to the story. Huck and Jim, who is an escaped slave, travel down the river on a raft. The river stands for freedom and escape. As they float along, they have many adventures, meet different people, and talk about big ideas like right and wrong, and what it means to be a friend. The river is always moving and changing, just like their journey. It gives them time and space to think and grow. Twain uses the river not just as a way to get from place to place, but as a symbol of the characters’ path to better understand themselves and the world around them.
In poetry, water is often used to show feelings and ideas. In the poem The Rime of the Ancient Mariner by Samuel Taylor Coleridge, a sailor tells a strange and sad story about being lost at sea. The huge ocean around him becomes a symbol of guilt, punishment, and mystery. One famous line from the poem is, “Water, water, every where, And all the boards did shrink; Water, water, every where, nor any drop to drink.” This shows how the ocean, which usually gives life, can also be dangerous and cruel. The poem uses water to teach a lesson, that people must respect nature and the spiritual world. In many myths and legends, water is part of a journey to another world. In the Greek story of Orpheus and Eurydice, Orpheus has to cross a river to enter the underworld and try to bring back his lost love. The river is a border between life and death, showing that water can mark the edge of what people understand. In an African story about Mami Wata, a water spirit appears in dreams and visions. She might bring healing, beauty, or riches, but she must be treated with respect.
 In movies 
Water is often used in movies to create powerful emotions, build tension, or act as an challenge for the characters. Directors use water in different ways. It can show danger, mystery, or fear, but it can also show peace, life, or change. In adventure and action movies, water can be exciting or dangerous. It can appear in scenes with storms, floods, or rescues from rivers or oceans. One well-known example is Titanic (1997), where the ocean is not only the setting but also a major cause of the disaster. At first, the sea looks calm and beautiful, but later, the cold water becomes a threat as the ship sinks. In fantasy and science fiction movies, water can be strange or magical. For example, in Avatar: The Way of Water, the ocean is a place full of unusual creatures and emotional moments. It is shown as both a home and a challenge for the characters.
In the animated movie Moana, water is shown as something that can move on its own and help the main character. The ocean guides Moana as she tries to save her island. It helps her when she is scared and keeps her safe from harm. In the movie, water acts like a helper. It also links Moana to her ancestors, who also sailed the oceans. The ocean in this story is not something to be afraid of but something to understand and rely on. In Finding Nemo (2003), the entire story takes place underwater. The ocean is full of sea life, reefs, and dangers. It shows that water can be both fun and dangerous. The underwater setting is important to the whole story. In Cast Away (2000), the ocean separates the main character from other people after a plane crash. The ocean becomes a challenge he must face, and it is also the way he must return to his normal life.
Water is also used in movies to show feelings or deeper meanings. In many dramas, rain can show sadness, being alone, or a big change in the story. For example, in The Notebook, the rain scene is full of strong emotion and shows an important moment between two characters. Water can also stand for a new beginning or change. In horror movies, water can make scenes more tense or scary. Dark lakes, bathtubs, or storms can trap people or hide something dangerous. In Jaws, for example, the ocean looks calm, but a shark is hiding below. People swim without knowing the danger, which creates fear and suspense. Water also works well in movies because it moves, reflects light, and makes sounds. Whether it is big waves, gentle rain, or quiet ponds, water adds something special to a scene. It helps tell the story in a visual way, sometimes more clearly than words can. This makes water one of the most useful natural elements in filmmaking.
 Dihydrogen monoxide parody 
The dihydrogen monoxide parody began as a funny joke in the early 1990s. It was meant to show how using big science words can confuse people and make safe things sound dangerous. "Dihydrogen monoxide" is just a fancy way of saying water. The word “dihydrogen” means two hydrogen atoms, and “monoxide” means one oxygen atom. That adds up to H₂O, which is the chemical formula for water. Even though it is just water, calling it “dihydrogen monoxide” makes it sound like a harmful chemical. This joke was used to show that many people do not always understand science words, and they can be tricked if something is explained in a dramatic or serious-sounding way.
One of the earliest and most famous uses of this joke happened in 1997, when a high school student named Nathan Zohner gave a science presentation titled "How Gullible Are We?". In his report, he described all the dangers of “dihydrogen monoxide”. Like causing burns (as steam), contributing to erosion, being found in cancer cells, and even causing death when inhaled. He did not say that it was just water until the very end. Out of 50 students who listened to his presentation, 43 voted to ban the chemical. Nathan’s project became famous, and it showed how people can be easily tricked if they do not have enough scientific knowledge or critical thinking.
Before that, versions of the joke had appeared in internet forums and emails, especially as the internet was growing in the 1990s. People used the parody to make fun of how the media, politicians, or even environmental activists might sometimes overreact to scientific information without fully understanding it. Over time, the joke spread widely and became part of internet culture. It is often used today in classrooms, debates, or websites to teach people to read carefully and to question information that sounds too dramatic or scary. The DHMO parody continues to be shared today, often as a reminder that how we present information really matters. If something is said with the right tone, long words, or half-truths, people might believe anything, even that water is dangerous. It is a funny but important lesson in science literacy, skepticism, and not jumping to conclusions without understanding the full picture. The website DHMO.org is a joke website which lists the harmful effects of water (DHMO), answers questions, and calls for it to be banned, among other things.
 In music 
Water has always been a big inspiration in music because it connects to so many feelings and ideas. People all over the world use water as a symbol in songs to show emotions like peace, sadness, change, power, or even mystery. Just like water can be calm or stormy, music about water can be soft and gentle or loud and intense. For example, a calm river or gentle rain might be used to create a peaceful feeling, while crashing waves or a flood might show strong emotions like anger, heartbreak, or chaos. Water can represent the flow of life, the passage of time, or the feeling of being overwhelmed by something big.
In classical music, composers have often used water to paint pictures with sound. For example, famous composers like Claude Debussy wrote pieces such as La Mer (The Sea), where the music was inspired by the sea. Another example is Frédéric Chopin’s "Raindrop Prelude", where repeating notes sound like gentle raindrops falling. These pieces do not use words, but the music still makes listeners feel like they are near water. In modern times, pop, rock, and folk songs also use water in their lyrics. Songs like Bridge Over Troubled Water by Simon & Garfunkel or River by Joni Mitchell use rivers and storms as ways to talk about emotions and life problems. In these songs, water can be both the problem and the solution. It can pull someone down, or it can wash their pain away.
In many cultures, water is tied to spiritual or emotional cleansing, so music about water is often healing or thoughtful. In African, Asian, and Indigenous traditions, water songs are sometimes sung during rituals, rain dances, or prayers, asking nature for help or giving thanks for life. In blues music, rivers often appear as symbols of sorrow or escape, especially in songs from the American South, where the Mississippi River became a symbol of travel, freedom, and sometimes grief. In reggae and Caribbean music, the sea and rain show up in joyful, laid-back songs that celebrate nature and the rhythm of island life.
Water even affects how music sounds. In some electronic or ambient music, water sounds like waves, rain, or dripping are added to create a relaxing background. These sounds are used in meditation music or sleep playlists because they help people feel calm and safe. Music therapists also use water sounds to help people reduce stress or connect with their emotions.


French Revolution: January 2019
September 2016
The French Revolution was a revolution in France from 1789 to 1804. It ended the French monarchy. The revolution began with a meeting of the Estates General in Versailles, and ended when Napoleon Bonaparte took power in November 1804.
Before 1789, France was ruled by the nobles and the Catholic Church. The ideas of the Enlightenment were beginning to make the ordinary people want more power. They could see that the American Revolution had created a country in which the people had power, instead of a king. The government before the revolution was called the "Ancien Régime".
 Causes of the revolution 
The problems in France that led up to the Revolution:
 Under the Kings Louis XV and Louis XVI, France had fought against Prussia and the British Empire in the Seven Years' War. They fought against Britain again in the American Revolution. They borrowed lots of money to pay for the wars, and the country became poor.
 The high price of bread and low wages of workers caused the ordinary people to suffer from hunger and malnutrition. This made them dislike the rich nobles, who had the money to eat well and build huge mansions.
 The Roman Catholic Church, which owned the most land in France, put a tax on crops called the dime (tithe) which hurt the poorest and hungriest people as they were not able to afford the tax.
 Ideals of Enlightenment. Many people disliked absolute rule by the royalty and the nobility. They could see that in other countries, like the United States, which had recently been formed, people like them had more power over the government. They also wanted freedom of religion.
 The first and the second estate i.e., the clergy and the nobility, enjoyed all the privileges and rights but the Third Estate (everyone else, middle class, city workers and peasants) had to pay tithes and taille (taxes paid to Church and the court).
 The "Estates-General" 
Before the Revolution, France was divided into three Estates. The First Estate was the clergy. It was 1% of the population. The Second Estate was the nobles, also 1% of the population. The other nearly 98% of the population was in the Third Estate. Representatives of the people from all three estates together made up the Estates-General. The Estates General first met in 1302 and 1303, and occasionally met in later centuries.
In May 1789, the Estates-General was called by King Louis in order to deal with the money problems of the country. They met at the royal Palace of Versailles. However, the members of the Third Estate were angry. They had made lists of problems they wanted to fix called the Cahiers de Doléance. They were angry that they were being taxed the most when they were the poorest group of people. They, and the Director-General of Finances, Jacques Necker, thought the Church and the Nobility ought to be taxed more.
They also wanted votes in the Estates-General to be more fair. Even though the Third Estate had many more members than the other two Estates, each Estate only had one vote in the Estates-General. The Third Estate thought this could be improved by giving members of the Estates-General a vote each. However, when they talked to the other Estates, they could not agree.
 Forming the National Assembly 
Since the First and Second Estates would not listen, The Third Estate decided to break away and start their own assembly where every member would get a vote. On 10 June 1789, they started the National Assembly. The king tried to stop them by closing the Salle des États meeting room, but they met in an indoor tennis court instead. On June 20, they took the Tennis Court Oath, where they promised to work until they had created a new constitution for France.
 The Storming of the Bastille
In July 1789, after the National Assembly was formed, the nobility and the king was angry with Jacques Necker, the Director-General of Finances, and they fired him. Many Parisians thought that the King was going to shut down the National Assembly. Soon, Paris was filled with riots and looting.
On 14 July 1789, the people decided to attack the Bastille prison. The Bastille contained weapons, as well as being a symbol of the power of the nobility and the rule of the king. By the afternoon, the people had broken into the Bastille and released the seven prisoners being held there.
The Members of the Third Estate took over Paris. The president of the National Assembly at the time of the Tennis Court Oath, Jean-Sylvain Bailly, became mayor of the city. Jacques Necker was given back his job as Director-General of Finances. Soon, the King visited Paris and wore the red, white and blue (tricolor) ribbons (cockade) that the revolutionaries were wearing. By the end of July, the revolution had spread all over France.
 The National Assembly 
The National Assembly began to make lots of changes. On August 4th, the National Assembly ended the special taxes the Church was collecting, and put a stop to the rights of the nobility over their people, ending feudalism. On August 26th, the National Assembly published the Declaration of the Rights of Man and of the Citizen, which was written by the nobleman Marquis de Lafayette.
The National Assembly began to decide how it would be under the new constitution. Many members, especially the nobles, wanted a senate or a second upper house. However, more people voted to keep having just one assembly. The King was given a suspensive veto over laws, which meant he would only have the power to delay laws being made, not stop them. In October 1789, after being attacked at the Palace of Versailles by a mob of 7,000 women, the King was convinced by Lafayette to move from Paris to the palace in the Tuileries.
The Assembly began to divide into different political parties. One was made up of those against the revolution, led by the nobleman Jacques Antoine Marie de Cazales and the churchman Jean-Sifrien Maury. This party sat on the right side. A second party was the Royalist democrats (monarchists) which wanted to create a system like the constitutional monarchy of Britain, where the king would still be a part of the government. Jacques Necker was in this party. The third party was the National Party which was centre or centre-left. This included Honoré Mirabeau and Lafayette.
 Ways the French church changed 
Under the new government, the Roman Catholic Church had much less power than they had before. In 1790, all special taxes and powers of the Church were cancelled. All the Church’s property was taken over by the state. On 12 July 1790, the Civil Constitution of the Clergy made all clergy employees of the state and made them take an oath to the new constitution. Many clergy, as well as the Pope, Pius VI, did not like these changes. Revolutionaries killed hundreds for refusing the oath.
 Working on the constitution 
On 14 July 1790, a year since the storming of the Bastille, thousands of people gathered in the Champs de Mars to celebrate. Charles Maurice de Talleyrand led the crowd in a religious mass. The crowd, including the King and the royal family, took an oath of loyalty to “the nation, the law, and the king.” However, many nobles were unhappy with the revolution and were leaving the country. They were called émigrés (emigrants).
Although the members of the Estates-General had only been elected for a year, the members of the Assembly had all taken the Tennis Court Oath. They had promised to keep working until they had a constitution and no constitution had been made. It was decided that the members would keep working until they had a constitution. The Assembly continued to work on a constitution and make changes. Nobles could no longer pass their titles to their children. Only the king was allowed to do this. For the first time, trials with juries were held. All trade barriers inside France were ended along with unions, guilds, and workers' groups. Strikes were banned.
Many people with radical ideas began to form political clubs. The most famous of these was the Jacobin Club, which had left-wing ideas. A right-wing club was the Club Monarchique. In 1791, a law was suggested to prevent noble émigrés from leaving the country. Mirabeau had been against this law, but he died on 2 April, and by the end of the year, the law was passed.
 Royal family tries to leave Paris 
Louis XVI did not like the revolution, but did not want to get help from other countries or run away from France like the émigrés. General Bouille held the same views and wanted to help the king leave Paris. He said that he would give the King and his family help and support in his camp at Montmédy. The escape was planned for June 20, 1791.
Dressed as servants, the royal family left Paris. However, their escape was not well planned, and they were arrested at Varennes on the evening of June 21. The royal family was brought back to Paris. The Assembly imprisoned Louis and his wife Marie Antoinette, and suspended the king from his duty.
 Completing the constitution 
Although the king had tried to escape, most members of the Assembly still wanted to include the king in their government rather than to have a Republic with no king at all. They agreed to make the king a figurehead, with very little power. The king would have to take an oath to the state. If he did not, or if he created an army to attack France, he would no longer be king.
Some people, including Jacques Pierre Brissot, did not like this. They thought the king should be completely removed from the throne and the constitution. Brissot made a petition and a huge crowd came to the Champs de Mars to sign it. Republican leaders Georges Danton and Camille Desmoulins came and gave speeches.
The National Guard, led by Lafayette, was called in to control the crowd. The mob threw stones at the soldiers who first fired their guns over the heads of the crowd. When the crowd kept throwing stones, Lafayette ordered them to fire at the people. Up to 50 people were killed. After this, the government closed many of the political clubs and newspapers. Many radical left-wing leaders, including Danton and Desmoulins, ran away to England or hid in France.
Finally the constitution was completed. Louis XVI was put back on the throne and came to take his oath to it. He wrote, “I engage to maintain it at home, to defend it from all attacks from abroad, and to cause its execution by all the means it places at my disposal.” The National Assembly decided that it would stop governing France on 29 September 1791. After that date, the Legislative Assembly would take over.
 The Legislative Assembly (1791-1792) 
The new Legislative Assembly met for the first time in October 1791. Under the Constitution of 1791, France was a constitutional monarchy. The King shared his rule with the Legislative Assembly, but had the power to stop (veto) laws he did not like. He also had the power to choose ministers.
The Legislative Assembly had about 745 members. 260 of them were “Feuillants”, or Constitutional Monarchists. 136 were Girondins and Jacobins, left-wing liberal republicans who did not want a king. The other 345 members were independent, but they voted most often with the left wing.
The Legislative Assembly did not agree very well. The King used his veto to stop laws that would sentence émigrés to death. Because so many of the members of the Assembly were left-wing, they did not like this.
 Crisis of constitution 
The people were turning against King Louis XVI. On 10 August 1792, the members of a revolutionary group called the Paris Commune attacked the Tuileries, where the King and Queen were living. The King and Queen were taken prisoner. The Legislative Assembly held an emergency meeting. Even though only a third of the members were there and most of them were Jacobins, they suspended the King from duty.
 War 
The kings and emperors of many foreign countries were worried by the French Revolution. They did not want revolutions in their own countries. On 27 August 1791, Leopold II of the Holy Roman Empire/Austria, Frederick William II of Prussia, and Louis XVI’s brother-in-law, Charles-Philippe wrote the Declaration of Pillnitz. The Declaration asked for Louis XVI to be set free and the National Assembly to be ended. They said that they would invade France if their requests were ignored. The Declaration was taken very seriously among the revolutionaries.
With the Legislative Assembly in place, the problems did not go away. The Girondins wanted war because they wanted to take the revolution to other countries. The King and many of his supporters, the Feuillants, wanted war because they thought it would make the King more popular. Many French were worried that the émigrés would cause trouble in foreign countries against France.
On 20 April 1792, the Assembly voted to declare war on Austria (Holy Roman Empire). They planned to invade the Austrian Netherlands, but the revolution had made the army weak. Many soldiers deserted. Soon, Prussia joined on the Austrian side. They both planned to invade. Together, on 25 July, they wrote the Brunswick Manifesto, promising that if the royal family was not hurt, no civilians would be hurt in the invasion. The French believed that this meant the king, Louis XVI, was working with the foreign kings. Prussia invaded France on 1 August, 1792. This first stage of the French Revolutionary Wars continued until 1797.
 September massacres 
In September, things got worse. The Legislative Assembly had almost no power. No single group was controlling Paris or France. The country was being invaded by the Prussian Army. The revolutionaries were very angry and violent. They began to go into prisons and kill people they thought were traitors to France. They hated the priests of the Roman Catholic Church the most, but they also killed many nobles and ordinary people. By 7 September, 1,400 people were dead.
 National Convention (1792-1795) 
The Legislative Assembly had lost all its power. France needed a new government. On 20 September 1792, the National Convention was formed. The Convention had both Girondins and radical Jacobins.
 Execution of Louis XVI 
The Brunswick Manifesto had made many people suspicious of the king. They thought he was plotting with the Prussian and Austrian rulers to invade France. In January 1793, the National Convention voted and found Louis XVI guilty of “conspiracy against the public liberty and the general safety.” On the twenty-first of January, the King was executed using the guillotine. Marie Antoinette, the Queen, was executed on the sixteenth of October.
 Revolt in Vendée 
People in the area of Vendée did not like the revolutionary government. They did not like the rules about the church in the Civil Constitution of the Church (1790) and new taxes put in place in 1793. They also disliked being forced to join the French army. In March, they rose up against the government in a revolt. The war lasted until 1796. Hundreds of thousands of people from Vendée (Vendeans) were killed by the Revolutionary French army.
 The Jacobins seize power 
Now that the king was dead, the National Convention made a new republican constitution that began on 24 June. It was the first one that did not include the king and gave every man in France a vote. However, it never came into force because of the trouble between the Jacobins and Girondins. The war with Austria and Prussia was causing the state to have money problems. Bread was very expensive and many people wanted things to change. In June 1793, the Jacobins began to take power. They wanted to arrest Girondin members of the National Convention. In July, they became angrier when Charlotte Corday, a Girondin, killed Jean-Paul Marat, a Jacobin.
By July, the coup was complete. The Jacobins had taken power. They put in new, radical laws including a new Republican Calendar with new months and new ten-day weeks. They made the army bigger and changed the officers to people who were better soldiers. Over the next few years, this helped the Republican army push back the attacking Austrians, Prussians, British, and Spanish.
 The Reign of Terror 
In July 1793, a Jacobin called Maximilien de Robespierre and eight other leading Jacobins set up the Committee of Public Safety. It was the most powerful group in France. This group and Robespierre were responsible for the Reign of Terror. Robespierre believed that if people were afraid, the revolution would go better. The Reign of Terror lasted from the spring of 1793 to the spring of 1794.
It was not only the nobility who died in the Reign of Terror. Anyone who broke the Jacobins' laws, or was even suspected of breaking their laws or working against them, could be arrested and sent to the guillotine, most without a trial. Even powerful people who had been involved in the Jacobin coup were executed. Prisoners were taken from the prisons to “Madame Guillotine” (a nickname for the guillotine) in an open wooden cart called the tumbrel. According to records, 16,594 people were executed with the guillotine. It is possible that up to 40,000 people died in prison or were killed during the Reign of Terror.
By July 1794, people began to turn against Maximilien de Robespierre. He and his Revolutionary Tribunal had killed 1,300 people in six weeks. On 27 July, the National Convention and the Committee of Public Safety turned against him. Robespierre tried to get help from the Convention’s right-wing members, but he failed. A day later, Robespierre and many of his supporters in the Paris Commune were sentenced to death by guillotine without any kind of trial. This reaction against Robespierre is called the Thermidorian Reaction.
Now that the terror was over, the National Convention started to make a new Constitution, called the Constitution of the Year III. On 27 September 1794, the constitution came into effect.
 The Directory (1795-1799) 
The new constitution had created the Directories (Directory), which was the first government of France to be bicameral (split into two houses). The lower house, the parliament, had 500 members. It was called the Conseil de Cinq-Cent (Council of Five Hundred). The upper house, the senate, had 250 members and was called the Conseil des Anciens (Council of Elders). There were five directors chosen every year by the Conseil des Anciens from a list made up by the Conseil de Cinq-Cent. This group was in charge and was called the Directory.
Although the constitution of 1793 had given all men in France a vote, in this constitution only people with a certain amount of property could vote. The Directory was much more than the governments in France since 1789. The people were tired of radical changes and the unstable governments. Things were much more stable under the Directory than they had been before.
However, the Directors were disliked by the people - especially the Jacobins, who wanted a republic, and the royalists, who wanted a new King. France’s money problems did not go away. The Directors ignored elections that did not go the way they wanted. They ignored the constitution in order to do things to control the people. They used the ongoing war and the army to keep their power.
 Coup of 18 Brumaire
The Coup of 18 Brumaire brought General Napoleon Bonaparte to power as First Consul of France on 9 November 1799. In the view of most historians it ended the French Revolution. This bloodless coup d'état overthrew the Directory, replacing it with the French Consulate.
The 18 Brumaire marks the end of the Republican part of the French Revolution when Napoleon Bonaparte took control.


Black hole: A black hole is a place in space where gravity is so strong that nothing can escape from it, not even light. Black holes are made when a lot of matter is squeezed into a very small space. This idea comes from Albert Einstein's general theory of relativity. The outer edge of a black hole is called the event horizon. When something enters the black hole, it cannot get out. Black holes act like perfect black bodies, which means they do not reflect any light. According to quantum mechanics, black holes can slowly release a tiny amount of energy called Hawking radiation. But this radiation is so weak that it cannot be seen with the technology today.
The idea of objects with gravity so strong that light cannot escape was first talked about in the 1700s by John Michell and Pierre-Simon Laplace. In 1916, Karl Schwarzschild found the first solution to Einstein's general relativity equations that was about a black hole. Because of his important work, this solution is called the Schwarzschild metric. In 1958, David Finkelstein was the first to call a black hole a place in space where nothing can escape. For a long time, people thought black holes were just an idea in mathematics. They thought black holes were not real. In 1967, Jocelyn Bell Burnell discovered neutron stars. The first black hole found was Cygnus X-1. It was found by lots of scientists in 1971.
Black holes usually form when very large stars die at the end of their life. Black holes can grow by eating gas, dust, stars, or even combining with other black holes. Supermassive black holes are black holes which are millions of times heavier than the Sun. These big black holes might be made by merging with other black holes, eating stars, or from the collapse of huge clouds of gas. Scientists agree that supermassive black holes can be found at the centers of almost every galaxy.
Even though black holes are invisible to us, scientists can still find them. They look at how they affect matter and light near them. When matter falls toward a black hole, it can form a spinning disk called an accretion disk. Friction in the disk heats it up. This makes it glow very brightly. Sometimes, this creates a quasar, one of the brightest things in the universe. This can be found by telescopes on Earth or by telescopes in space such as Chandra or XMM Newton. Sometimes, if a star gets too close to a supermassive black hole, it can be torn apart into a bright stream of gas before being swallowed.<ref>Wald, Robert M. 1992. Space, time, and gravity: the theory of the Big Bang and black holes. University of Chicago Press. ISBN 978-0-226-87029-8</ref> Scientists can also find black holes by looking at how stars move. If a star moves around something invisible, scientists can find out the mass and location of the invisible object. This helps them know it is a black hole and not something else like a neutron star. Astronomers have found some black holes. However, "estimates from NASA [... say that maybe there are] as many as 10 million to a billion [black holes or] stellar black holes in the Milky Way", according to media (2025).
One was found at the center of our galaxy. This black hole, called Sagittarius A*, is about 4.3 million times heavier than our Sun.
The black hole closest to Earth, is Gaia BH1. Its distance from Earth is about 1,500 light-years.
 History 
In 1783, an English clergyman named John Michell wrote that it might be possible for something to be so heavy you would have to go at the speed of light to get away from its gravity. Gravity gets stronger as something gets more massive. For a small thing, like a rocket, to escape from a larger thing, like Earth, it has to escape the pull of the Earth's gravity or it will fall back. The speed that it must travel to get away is called escape velocity. Bigger planets (like Jupiter) and stars have more mass, and have stronger gravity than Earth. Therefore, the escape velocity would need to be much faster. John Michell thought it was possible for something to be so big that the escape velocity would need to be faster than the speed of light, so even light could not escape. In 1796, Pierre-Simon Laplace wrote about the same idea in the first and second editions of his book Exposition du système du Monde (it was removed from later editions).
Some scientists thought Michell might be right, but others thought that light had no mass and would not be pulled by gravity. His theory was forgotten.
In 1916 Albert Einstein wrote an explanation of gravity called general relativity.
 Mass causes space (and spacetime) to bend, or curve. Moving things "fall along" or follow the curves in space. This is what we call gravity.
 Light always travels at the same speed, and is affected by gravity. If it seems to change speed, it is really traveling along a curve in spacetime.
A few months later, while serving in World War I, the German physicist Karl Schwarzschild used Einstein's equations to show that a black hole could exist. The Schwarzschild radius is the size of the event horizon of a non-rotating black hole. This radius was the measurement where the escape velocity was equal to the speed of light. If the radius of a star is smaller, then light is unable to escape, and it would be a dark star, or black hole.
In 1930, Subrahmanyan Chandrasekhar predicted that stars heavier than the sun could collapse when they ran out of hydrogen or other nuclear fuels to burn. In 1939, Robert Oppenheimer and H. Snyder calculated that a star would have to be at least three times as massive as the Sun to form a black hole. In 1967, John Wheeler invented the name "black hole" for the first time. Before that, they were called "dark stars".
In 1970, Stephen Hawking and Roger Penrose showed that black holes must exist. Although the black holes are invisible (they cannot be seen), some of the matter that is falling into them is very bright.
As of spring 2019, there was an image of a black hole, or rather, the things orbiting the black hole. The image required many photos from different locations. One of the team members (Katie Bouman) made a compilation of all the images into one singular image.
In 2020, Roger Penrose, Reinhard Genzel and Andrea Ghez were awarded the Nobel Prize in Physics for their work on the theory of black holes.
 Formation of black holes 
The gravitational collapse of huge (high-mass) stars cause "stellar mass" black holes. This happens when really big stars run out of fuel.
Star formation in the early universe may have created very big stars. These stars were so large that their cores collapsed into black holes. The black hole at the center of these stars slowly consumed the star from within making black holes of up to 103 solar masses. These black holes may be the seeds of the supermassive black holes found in the centers of most galaxies. If these stars really existed, they may even explain where supermassive black holes come from.
Most of the energy released in gravitational collapse is given off very quickly. A distant observer sees the material falling in slowly and then stop just above the event horizon because of gravitational time dilation. The light given off just before the event horizon is delayed an infinite amount of time. So the observer never sees the formation of the event horizon. Instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away.
 Supermassive black holes 
Black holes have also been found in the middle of almost every galaxy in the known universe. These are called supermassive black holes (SBH), and are the biggest black holes of all. They formed when the Universe was very young, and also helped to form all the galaxies.
Quasars are believed to be powered by gravity collecting material into supermassive black holes in the centers of distant galaxies. Light cannot escape the SBHs at the center of quasars, so the escaping energy is made outside the event horizon by gravitational stresses and immense friction on the incoming material.
Huge central masses (106 to 109 solar masses) have been measured in quasars. Several dozen nearby large galaxies, with no sign of a quasar nucleus, have a similar central black hole in their nuclei. Therefore, it is thought that all large galaxies have one, but only a small fraction are active (with enough accretion to power radiation) and so are seen as quasars.
 Parts of a Black Hole 
 The Event Horizon 
A black hole is separated from the rest of the Universe by its event horizon. Anything which crosses it cannot escape, not even light. Anything that happens inside this boundary can't be seen from the outside.
Near a black hole, time appears to slow down. This is known as gravitational time dilation. This happens because gravity affects time. The stronger the gravity, the slower time passes. Objects seem to turn red and fade away when they reach the event horizon. This is known as gravitational redshift. 
The shape of the event horizon for non-rotating black holes is spherical and slightly flattened for spinning ones.
The photon sphere is a spherical boundary of zero thickness in which photons that move on tangents to that sphere would be trapped in a circular orbit about the black hole.
 Effect on light 
At the middle of a black hole, there is a gravitational center called a singularity. It is impossible to see into it because the gravity prevents any light escaping.
Outside the event horizon, light and matter will still be pulled toward the black hole. If a black hole is surrounded by matter, the matter will form an "accretion disk" around the black hole. An accretion disk looks something like the rings of Saturn. As it gets sucked in, the matter gets very hot and shoots x-ray radiation into space. Think of this as the water spinning around the hole before it falls in.
Most black holes are too far away for us to see the accretion disk and jet. The only way to know a black hole is there is by seeing how stars, gas and light behave around it. With a black hole nearby, even objects as big as a star move in a different way, usually faster than they would if the black hole was not there.
Since we cannot see black holes, they must be detected by other means. When a black hole passes between us and a source of light, the light bends around the black hole creating a mirror image. This effect is called gravitational lensing.
 Hawking radiation 
Hawking radiation is black body radiation which is emitted by black holes, due to quantum effects near the event horizon. It is named after the physicist Stephen Hawking, who provided a theoretical argument for its existence in 1974.
Hawking radiation reduces the mass and the energy of the black hole and is therefore also known as black hole evaporation''. This happens because of the virtual particle-antiparticle pairs. Due to quantum fluctuations, this is when one of the particles falls in and the other gets away with the energy/mass. Because of this, black holes that lose more mass than they gain through other means are expected to shrink and ultimately vanish. Micro black holes (MBHs) are predicted to be larger net emitters of radiation than larger black holes and should shrink and dissipate faster.
 Properties of black holes 
The no hair theorem basically says that once a black hole has formed, it only has three physical properties that we can measure: mass, charge, and spin. If this is true, then if two black holes had the same mass, charge and spin then they will look the same. As of 2020, it is unclear if the no hair theorem is true for real black holes.
The properties are special, because all of them can be measured from outside the black hole. For example, a charged black hole repels other like charges just like any other charged object. Similarly, the total mass inside a sphere containing a black hole can be found by using the gravitational analog of Gauss's law, far away from the black hole. The angular momentum or spin can also be measured from far away.
When anything falls into a black hole, any property that is not part of the three properties of a black hole, like shape or charge distribution, gets erased and cannot be seen from outside. This is a very big problem because we lose a lot of information about what went into the black hole, including certain quantum properties and physics tells us that information cannot be destroyed. This puzzle is called the black hole information loss paradox.


Mathematics: July 2018
Mathematics is the study of numbers, shapes, and patterns. The word comes from the Greek μάθημα (máthema), meaning "science, knowledge, or learning", and is sometimes shortened to math or maths.
It is the study of:
 Numbers: including how things can be counted.
 Structure: including how things are organized, but also how they can be or could have been. This subfield is usually called algebra.
 Place: where things are, and spatial arrangement, including arrangements of spaces themselves. This subfield is usually called geometry.
 Change: how things become different. This subfield is usually called analysis.
Applied math is useful for solving problems in the real world. People working in business, science, engineering, and construction use mathematics.
 Problem-solving in mathematics 
Mathematics solves problems by using logic. One of the main tools of logic used by mathematicians is deduction. Deduction is a special way of thinking to discover and prove new truths using old truths. To a mathematician, the reason something is true (called a proof) is just as important as the fact that it is true, and this reason is often found using deduction. Using deduction is what makes mathematical thinking different from other kinds of scientific thinking, which might rely on experiments or on interviews.
Logic and reasoning are used by mathematicians to create general rules, which are an important part of mathematics. These rules leave out information that is not important so that a single rule can cover many situations. By finding general rules, mathematics solves many problems at the same time as these rules can be used on other problems. These rules can be called theorems (if they have been proven) or conjectures (if it is not known if they are true yet). Most mathematicians use non-logical and creative reasoning in order to find a logical proof.
Sometimes, mathematics finds and studies rules or ideas that we don't understand yet. Often in mathematics, ideas and rules are chosen because they are considered simple or neat. On the other hand, sometimes these ideas and rules are found in the real world after they are studied in mathematics; this has happened many times in the past. In general, studying the rules and ideas of mathematics can help us understand the world better. Some examples of math problems are addition, subtraction, multiplication, division, calculus, fractions and decimals. Algebra problems are solved by evaluating certain variables. A calculator answers every math problem in the four basic arithmetic operations.
 Areas of study in mathematics 
 Number 
Mathematics includes the study of numbers and quantities. It is a branch of science that deals with the logic of shape, quantity, and arrangement. Most of the areas listed below are studied in many different fields of mathematics, including set theory and mathematical logic. The study of number theory usually focuses more on the structure and behavior of the integers rather than on the actual foundations of numbers themselves, and so is not listed in this given subsection.
{| style="border:1px solid #999; text-align:center;" cellspacing="20"
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| Natural numbers || Integers || Rational numbers || Real numbers || Complex numbers
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|| Ordinal numbers || Cardinal numbers || Arithmetic operations || Arithmetic relations || Functions, see also special functions
|}
 Structure 
 Structural mathematics studies objects' and constructions' shape and integrity. These are areas of algebra and calculus.
{| style="border:3px solid #999; text-align:center;" cellspacing="30"
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| Number theory || Abstract algebra || Linear algebra || Order theory || Graph theory
|}
 Shape 
Some areas of mathematics study the shapes of things. Most of these areas are part of the study of geometry.
{| style="border:1px solid #999; text-align:center;" cellspacing="20"
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| Topology || Geometry || Trigonometry || Differential geometry || Fractal geometry
|}
 Change 
Some areas of mathematics study the way things change. Most of these areas are part of the study of analysis.
{| style="border:1px solid #999; text-align:center;" cellspacing="40"
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| Calculus || Vector calculus || Analysis
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|| Differential equations || Dynamical systems || Chaos theory
|}
 Applied mathematics 
Applied math uses symbolic logic to solve problems in areas like engineering and physics.
Numerical analysis – Optimization – Probability theory – Statistics – Mathematical finance – Game theory – Mathematical physics – Fluid dynamics - Computational algorithms
 Famous theorems 
These theorems and conjectures have interested mathematicians and amateurs alike:
Pythagorean theorem – FLT – Goldbach's conjecture – Twin Prime Conjecture – Gödel's incompleteness theorems – Poincaré conjecture – Cantor's diagonal argument – Four color theorem – Zorn's lemma – Euler's Identity – Church-Turing thesis
These theorems and hypotheses have greatly changed mathematics:
Central limit theorem classification theorems of surfaces – Continuum hypothesis – Fourier Theorem – Fundamental theorem of calculus – Fundamental theorem of algebra – Fundamental theorem of arithmetic – Fundamental theorem of projective geometry – Gauss-Bonnet theorem - Kantorovich theorem – P Versus NP – Pythagorean theorem – Riemann hypothesis
These are a few conjectures that have been called "revolutionary":
Beal Conjecture (a generalization of FLT) – Birch and Swinnerton-Dyer Conjecture – Collatz Conjecture – Goldbach's Conjecture –Hodge Conjecture – Poincaré Conjecture
 Foundations and methods 
Set theory – Symbolic logic – Model theory – Category theory – Logic – Table of mathematical symbols
 History and the world of mathematicians 
History of mathematics – Timeline of mathematics – Mathematicians – Fields medal – Abel Prize – Millennium Prize Problems (Clay Math Prize) – International Mathematical Union – Mathematics competitions – Lateral thinking – Mathematics and gender
 Awards in mathematics 
There is no Nobel Prize in mathematics. Mathematicians can receive the Abel Prize and the Fields Medal for important works.
The Clay Mathematics Institute has said it will give one million dollars to anyone who solves one of the Millennium Prize Problems.
 Mathematical tools 
There are many tools used to do math or find answers to math problems.
Older tools
 Abacus
 Napier's bones, Slide rule
 Ruler and Compass
 Mental calculation
 Writing
Newer tools
 Graphing calculators, scientific calculators and more complex computer visual tools
 Programming languages
 Computer algebra systems (listing) and automated matrix analysis
 statistics software (for example SPSS)
 SAS (programming language)
 R (programming language)


Science in the ancient world: Science in the ancient world includes the earliest times when people started to explore and understand the world around them. Before writing was invented, people shared knowledge through stories and spoken words. Once writing began, it helped people keep and share their knowledge more accurately.
The first scientific ideas came from the Ancient Near East, especially in Ancient Egypt and Mesopotamia (in today’s Iraq). Later, science developed in Persia, Greece, Rome, India, China, and Mesoamerica. Even though ideas like alchemy and astrology became less important later on, these ancient cultures helped create the beginnings of modern science.
 Ancient Near East – Mesopotamia 
Around 3500 BC, in Sumer (a region in Mesopotamia), people began writing down what they saw in the sky. They used numbers and symbols to record their observations.
 Mathematics 
People in Mesopotamia were already using math very early. A famous clay tablet called Plimpton 322 (from around 1800 BC) shows they understood the Pythagorean theorem (a math rule about triangles). The tablet lists number groups like (3, 4, 5) and (5, 12, 13), which fit that rule.
 Astronomy 
The Babylonians were some of the first people to study the stars and planets using math. They wrote down their findings on clay tablets. They knew about the movement of the stars, the Sun, the Moon, and the planets. They also created calendars based on the solar year and the lunar month.
They could predict things like:
 The phases of the Moon
 How long days would be during the year
 Solar and lunar eclipses
A few ancient scientists are known by name. One was Kidinnu, who figured out a very accurate length for the solar year—his number is still used in calendars today.
Later scientists like Hipparchus and Al-Battani used this data to learn even more. Al-Battani calculated how Earth’s axis slowly moves (called precession). His number was very close to the one we use today.
At that time, astronomy and astrology (the study of horoscopes and omens) were closely linked. Over time, Babylonian astronomy focused more on astrology.
 Archaeology in Ancient Mesopotamia 
After the fall of many ancient kingdoms (around 1200 BC), science still continued in some places. One king, Nabonidus of the Neo-Babylonian Empire, acted like the first archaeologist.
Around 550 BC, he found old items from temples that were built by an earlier king, Naram-Sin (from around 2200 BC). Nabonidus studied these objects and tried to figure out how old they were. He was the first known person in history to try dating ancient artifacts, even though his guesses were not always correct.
 Ancient Egypt 
Ancient Egypt made many important discoveries in astronomy, mathematics, and medicine. It was also a major center for alchemy, a practice that mixed early science and magic and later influenced Western science.
 Architecture, engineering, and math 
The Egyptians used geometry to measure land, especially after the Nile River flooded each year and washed away farm borders. They used simple math rules, like the 3–4–5 triangle, to build straight and solid structures. These rules helped them design buildings such as temples and pyramids, often using posts and lintels (horizontal beams supported by vertical ones).
 Writing 
Egyptians used hieroglyphs, a system of picture writing. This writing later helped create the Proto-Sinaitic script, which became the ancestor of alphabets like Phoenician. Many modern alphabets—such as Hebrew, Greek, Latin, Arabic, and Cyrillic—developed from this.
The city of Alexandria in Egypt was famous for its great library, which collected books and knowledge from many cultures. When Alexandria came under Roman rule, the library was damaged by fire and was finally destroyed by 642 AD. Much ancient knowledge was lost with it.
 Medicine 
Egyptian doctors were some of the first to study and treat health problems. One of the oldest medical texts, the Edwin Smith Papyrus, even describes the brain, making it one of the earliest works related to neuroscience. Ancient Egyptian medicine included steps like:
 Examining the patient
 Diagnosing the problem
 Giving treatment
 Predicting the outcome
This approach was similar to the scientific method used in modern medicine.
Another text, the Ebers Papyrus (from around 1550 BC), shows that Egyptians used experience and observation (called empiricism) in their treatments.
However, not all their medical methods were useful. A study by Michael D. Parkins found that 72% of treatments in the Hearst Papyrus likely had no healing power. Some methods—like using cow dung, lizard blood, or fly specks—could have been harmful.
Egyptian medicine also involved things like:
 Piercing ears
 Tattooing
 Treating wounds (often in unsafe ways)
These practices sometimes led to infections like tetanus. Even though not all treatments were effective, ancient Egypt laid the groundwork for the idea of studying and treating diseases scientifically.
 Persia 
In ancient Persia, especially during the time of the Sassanid Empire, people focused a lot on math and astronomy (the study of stars and planets). A famous learning center from this time was the Academy of Gondishapur, where many scholars worked.
During this time, astronomical tables (charts of star and planet movements) were created. These ideas and methods were later used by Muslim scientists during the Islamic Golden Age.
In the middle of the Sasanian period, Greek knowledge came to Persia, especially through Christian ideas and the Syriac language (a form of Aramaic). This helped mix Greek and Persian science.
Later, in the Early Middle Ages, Persia became an important center for Islamic science. After the Umayyad and Abbasid empires were created, many Persian scholars moved to the capitals of these Islamic kingdoms to share their knowledge and continue learning.
 Greco-Roman World 
The Greco-Roman world (also called classical antiquity) made many important discoveries in areas like anatomy, animals, plants, minerals, geography, math, and astronomy. Scholars also began to ask deeper questions about how and why things change in nature.
 Scientific thinking 
During the Hellenistic period (after Alexander the Great), Greek thinkers used math and careful observation to study the world. They didn’t just guess—they tested their ideas.
Science had two goals:
 To solve real-life problems, like making calendars or improving medicine
 To answer big questions about nature (this was called natural philosophy)
The first scientists were often called natural philosophers. They thought of themselves as smart workers or followers of certain beliefs.
 Early Greek thinkers 
Thales (6th century BC) is known as the "father of science". He tried to explain things like lightning and earthquakes without saying they were caused by gods.
Pythagoras started a school that studied math and was the first to say the Earth is round.
Around 385 BC, Plato started the Academy, a school for deep thinking. His student Aristotle helped start a “scientific revolution,” which grew in the 3rd and 2nd centuries BC with great minds like:
 Eratosthenes
 Euclid
 Aristarchus of Samos
 Hipparchus
 Archimedes
Plato and Aristotle also helped create logical thinking (like using evidence to prove something), which is still used in science today.
 Astronomy and engineering 
A famous invention from this time is the Antikythera mechanism, an ancient machine that could track planets and stars.
Aristarchus of Samos said the Sun is at the center of the Solar System (heliocentric model).
Eratosthenes figured out the size of the Earth with amazing accuracy.
Hipparchus made the first organized map of the stars.
 Mathematics 
Euclid wrote The Elements, a book that shaped modern math rules, including ideas like axioms and proofs.
Archimedes worked on geometry, calculated pi, and made discoveries in physics, like how levers and water pressure work.
 Medicine 
Herophilos was one of the first to dissect human bodies to learn how they work. He studied the nervous system.
Hippocrates and his followers carefully described diseases and how to treat them.
Galen did brain and eye surgeries, some of which were not repeated for over 1,000 years.
 Minerals and nature 
Theophrastus wrote about plants, animals, and minerals. He was one of the first to classify them by their features, like hardness.
Pliny the Elder wrote a huge book called Natural History in 77 AD. He described the shape of diamonds, noticed how crystals grow, and explained that amber comes from tree sap because he found insects trapped inside it.
Pliny’s work helped start the science of mineralogy and crystallography (the study of crystals).
 Indian Subcontinent 
Ancient India made important progress in science and technology. One example is the Iron Pillar of Delhi, which shows that India was skilled in working with metals a long time ago.
 Math and engineering 
In the Indus Valley Civilization (Harappa and Mohenjo-daro), people used practical math:
 They made bricks in the ratio 4:2:1, which made buildings stronger.
 They used a standard system of weights, often shaped like cubes, cones, and cylinders. This shows they understood geometry.
 They made rulers to measure things very accurately. A ruler found in Mohenjo-daro had units as small as 3.4 cm, divided into 10 parts.
Later, between 400–1200 AD, Indian mathematicians like Aryabhata, Brahmagupta, Bhaskara II, and Mahaviracharya made big discoveries:
 They helped develop the decimal system, zero, negative numbers, and algebra.
 They improved trigonometry, creating the modern ideas of sine and cosine.
 The Hindu-Arabic number system, which we use today, came from India. A French monk (later Pope Sylvester II) helped spread it in Europe in the 11th century.
The Bakhshali manuscript (dated between 200–600 AD) shows the use of negative numbers, later clearly explained by Brahmagupta.
 Medicine 
At Mehrgarh (a very old site), scientists found proof of tooth drilling in human skeletons from around 7000–5500 BC.
Ayurveda is India’s traditional medicine. It comes from the Atharvaveda, one of the holy books of Hinduism. Important texts include the Sushruta Samhita, written by Sushruta, who lived around 1000 BC. This book talks about surgery and treatments.
Ayurveda was used a lot during the time of Buddha (around 520 BC). During Chandragupta II’s rule (375–415 AD), Ayurveda was a main medical system in India. It continued to be widely used until colonial times.
 Astronomy 
Indian astronomy began with the Vedas. Early ideas included:
 The universe started from nothing.
 The Earth is round and supports itself.
 A year has 360 days, divided into 12 months of 30 days.
Later, during the Maurya to Vijayanagara Empires, Indian astronomy became more advanced:
 Aryabhata wrote books like the Aryabhatiya with important ideas about space and math.
 Varahamihira wrote the Pancha-siddhantika, which described five earlier systems of astronomy.
Indian astronomy used star-based (sidereal) calculations but sometimes also used season-based (tropical) systems.
 Alchemy 
Alchemy (early chemistry) was also popular. The philosopher Kanada said that all matter is made from small, indivisible parts called anu—like atoms in modern science.
 Language and grammar 
Indian scholars were the first to deeply study language:
 Panini wrote a very detailed grammar of Sanskrit, explaining how sounds and words work.
 Hemachandra wrote about Sanskrit and Prakrit languages. His book described six Prakrits and even the rare Apabhramsha language.
Their work helped shape the study of linguistics, the science of language.
 Pre-Columbian Mesoamerica 
This region includes ancient cultures like the Olmec, Zapotec, and Maya, who lived in parts of what are now Mexico and Central America before Columbus came to the Americas.
 Writing 
Between 900 BC and 300 BC, the Zapotec or Olmec people created the first full writing systems in the Americas. The Cascajal Block may be the oldest written record found.
The Maya developed their own writing system between 400 and 200 BC. It was based on earlier systems from the Olmecs and Zapotecs.
By 100 BC, the Maya script was used widely. It became the most advanced writing system in Mesoamerica, with symbols used for recording history, religion, astronomy, and math.
 Mathematics 
The Maya used a base-20 number system.
They also used the number zero, which was very advanced for the time.
They created special symbols for the numbers 1 to 19, which helped them build accurate calendars.
 Astronomy 
The Zapotecs made the first known calendar in Mesoamerica. It may have been influenced by the Olmecs.
The Maya took astronomy even further. Their writing includes calendar dates using symbols for numbers and time periods.
These dates helped track religious, political, and social events over years and even decades.


Adolf Hitler: Hitler Hitler (name)
Adolf Hitler (20 April 1889 – 30 April 1945) was an Austrian-born German politician who was the dictator of Nazi Germany from 1933 until his suicide in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor in 1933 and then taking the title of Führer und Reichskanzler (Führer and Chancellor of the Reich) in 1934. His invasion of Poland on 1 September 1939 marked the start of the Second World War. He was closely involved in military operations throughout the war and was central to the perpetration of the Holocaust: the genocide of about six million Jews and millions of other victims.
Hitler was born in Braunau am Inn in Austria-Hungary and was raised near Linz. He lived in Vienna in the first decade of the 1900s before moving to Germany in 1913. He was decorated during his service in the German Army in World War I, receiving the Iron Cross. In 1919, he joined the German Workers' Party (DAP), the precursor of the Nazi Party. Hitler became the leader of the Nazi Party in 1921. In 1923, he attempted to seize governmental power in a failed coup in Munich and was imprisoned with a sentence of five years. In jail, he dictated the first volume of his autobiography and political manifesto Mein Kampf ("My Struggle"). He led them to become the most powerful political party in Germany after the 1932 elections. He began running the government when he became the Chancellor of Germany in 1933. The Nazis banned all other political parties and turned Germany into a dictatorship (meaning that the government was ruled by one person). Hitler's dictatorship is known as Nazi Germany, also known as the "Third Reich" (meaning "Third Empire" or "Third Realm"). Hitler called himself the Führer (meaning "leader") after the year 1934. 
Hitler ordered the takeover of Poland in 1939, and this started World War II in Europe. Hitler made all the important decisions during the war. At first, Nazi Germany did well in the war, but by 1945 they were losing. On 29 April 1945, Hitler married his longtime lover, Eva Braun, in the Führerbunker in Berlin. Less than two days later, Hitler and Braun killed themselves as the Soviet Army got to Berlin, because they did not want to be captured alive by the Soviet Union.
Because of the Nazi government, at least 50 million people died. About 28.7 million soldiers and people died in the fighting. The war also killed 19.3 million civilians and prisoners of war. Nazi forces committed many war crimes and atrocities during the war. They killed their enemies sometimes with mobile death squads or put them in concentration camps and death camps. Hitler and his men persecuted and killed Jews and other ethnic, religious, and political minorities. In what is called the Holocaust, the Nazis killed six million Jews, Roma people, homosexuals, Slavs, and many other groups of people.
 Family background 
Hitler's family was born in Waldviertel, in Lower Austria. At the time, the name Hitler changed in this region several times between Hüttler, Hiedler, Hittler and Hitler. The name was commonly in the German-speaking area of Europe in the 19th century. The literature says that this name is descended from the Czech name Hidlar or Hidlarcek.
 Childhood and early adulthood 
Adolf Hitler was born on 20 April 1889, as the fourth child of six in Braunau am Inn. This is a small town near Linz in the province of Upper Austria, close to the border with Germany. At the time, the town was in Austria-Hungary. His parents were Klara Pölzl and Alois Hitler. Because of his father's job, Hitler moved from Braunau to Passau, later to Lambach and finally to Leonding. He attended several Volksschule's.
Hitler's mother, Klara Pölzl, was his father's third wife and also his cousin. Hitler's father died in 1903. Hitler was born with only one testicle.
Hitler failed high school exams in Linz twice. In 1905, he left school. He became interested in the anti-Semitic (anti-Jewish), Pan-German teachings of Professor Leopold Poetsch. In September 1907, he went to Vienna and took an entrance examination. On 1 and 2 October, he failed the second examination. Hitler went back to Linz at the end of October. In December 1907, Hitler's mother died and, because of that, he was depressed. Hitler's mother was Catholic, but Hitler is not known to have been personally interested in Christianity.
In 1909, Hitler again went to Vienna to study art. He tried to become a student at the Academy of Arts, but failed the first entrance examination. He made many paintings and sold them at low prices. Hitler said he first became an anti-Semite in Vienna. This city had a large Jewish community.
In 1913, Hitler was 24 years old. At that time, all young Austrian men had to join the army. Hitler did not like the Austrian army and the Austro-Hungarian Empire because of its many ethnic groups, so he left Austria for Germany. He lived in the German city of Munich.
 World War I 
On 16 August 1914, Hitler joined the Bavarian army. He fought for the German Empire in World War I. Hitler served in Belgium and France in the 16th Bavarian Reserve Regiment. He spent nearly the whole time on the Western Front. He was a runner, one of the most dangerous jobs on the Front. That means he ran from one position to another, carrying messages. On 1 November 1914, Hitler became a Gefreiter (which was like being a private first class in the United States Army, or a lance corporal in the British Army). The government awarded him the Iron Cross Second Class on 2 December 1914.
On 5 October 1916, Hitler was hurt by a bullet shell. Between 9 October and 1 December, he was in the military hospital Belitz. In March 1917, he went back to the front. There, he fought in a battle and was awarded with the Militärverdienstkreuz Third Class with swords.
In March 1918, Hitler participated in the Spring Offensive. On 4 August 1918, Hitler was awarded the Iron Cross First Class by the Jewish Hugo Gutmann. After Germany surrendered, Hitler was shocked, because the German army still held enemy area in November 1918.
 Entry into politics 
After World War I, Hitler stayed in the army and returned to Munich. There he attended the funeral march of the Bavarian prime minister Kurt Eisner, who had been killed. In 1919, he participated in a training programme for propaganda speakers from 5 to 12 June and 26 June to 5 July.
Later that year, Hitler joined a small political party called the German Workers Party. He became member number 555. He soon won the support of the party's members. Two years later, he became the party's leader. He renamed the party the National Socialist German Workers Party. It became known as the Nazi Party.
 During the Weimar Republic 
In 1923, Hitler got together several hundred other members of the Nazi Party and tried to take over the Weimar Republic government (1918–34) in the Beer Hall Putsch. The coup failed. The government killed 13 of his men (the 13 dead men were later declared saints in Nazi ideology). They also put Hitler in the Landsberg Prison. They said that he would stay in prison for five years, but they let him leave after nine months.
Mein Kampf
While Hitler was in prison, he wrote a book with the help of his close friend Rudolf Hess. At first, Hitler wanted to call the book Four and a Half Years of Struggle against Lies, Stupidity and Cowardice. In the end, he called the book "Mein Kampf" ("My Struggle").
Mein Kampf brought together some of Hitler's different ideas and explains where they came from:
 His idea that the "Aryan race" was better than everybody else: This came from Arthur de Gobineau's book called The Inequality of the Human Races.
 His plans for an Empire in the East: These plans came from the way Germany had captured farming land in the First World War.
 His idea that democracy (rule by governments vote in elections) should be replaced by dictatorship (rule by one man)
 The idea that Judaism and communism were connected: He got this idea from the Nazi writer Alfred Rosenberg.
 His anger against the Jews. He suggests that they should be killed, though he is not clear about how this should be done.
Hitler may also have been influenced by Martin Luther's On the Jews and their Lies. In Mein Kampf, Hitler says Martin Luther was "a great warrior, a true statesman and a great reformer."
 Rise to power 
In January 1933, Hitler was elected into the German government and became a dictator in the next months. He ended freedom of speech, freedom of the press and put his enemies in prisons and concentration camps or killed them. He banned every other political party except the Nazi Party by the summer of 1933 and Germany became a one-party state. Hitler and his propaganda minister, Joseph Goebbels, spread extreme nationalism within Germany. All media came under the control of the Nazi Party and they had to praise Hitler and the Nazis. Also, more people were born because Hitler wanted more people of the "master race" (those he called "Aryans"). After the death of Paul von Hindenburg in 1934, Hitler declared the office of President vacant and made himself Führer (both Head of State and Head of Government) and became a full dictator with no checks and balances. He made Germany a totalitarian fascist dictatorship.
Hitler was also responsible for the Beer Hall Putsch of 1923. In the Night of the Long Knives of 1934 he had Ernst Röhm the head of the SA killed by Heinrich Himmler, Reinhard Heydrich and the SS. They were also involved in the Kristallnacht (1938).
 World War II 
Hitler is credited with starting World War II on September 1, 1939 by ordering the German Army to invade Poland. His army took over western Poland, and later most of Europe, including France and a large part of the Soviet Union.
 The Holocaust 
During the war, Hitler ordered the Nazis to kill many people, including women and children. The Nazis killed around six million Jews in the Holocaust. Other people that the Nazis killed were Roma (Gypsies), homosexuals, Slavs such as Russians and Poles, and his political opponents.Hitler spared his Jewish teacher also.
Finally, some of the other countries in the world worked together to defeat Germany. Hitler lost all of the lands that he had taken. Millions of Germans were killed in the war. At the end of World War II, Hitler gave all people in the Führerbunker permission to leave it. Many people did and moved to the region of Berchtesgaden. They used planes and truck convoys.
Hitler, the Göbbels family, Martin Bormann, Eva Braun and some other staff remained in the bunker. Hitler married Eva Braun on 29 April 1945.
Death
Forty hours after Hitler and Eva Braun got married in Berlin, Germany, both of them committed suicide: Eva Braun, by poisoning with cyanide; Hitler also gave some to his German Shepard. Then, Hitler committed suicide by shooting himself in the head with his gun. Before this, Hitler ordered that their bodies be burned after they were dead. This prevented him from being captured alive by soldiers of the Red Army, who were closing in on him. Despite this, there are theories that Hitler did not die in 1945, but that he instead escaped to Argentina. These theories are very unpopular, with most historians dismissing them.
Hitler in history
Ian Kershaw, a historian who wrote a biography (life story) of Hitler, describes him as a modern symbol of evil. "Never in history has such ruination ... been [linked] with the name of one man." However, Kershaw and some other historians believe that it is more important to look at the wider problems in Germany at the time, rather than at Hitler himself, to explain why the war and the Holocaust happened.


United Kingdom: June 2018
The United Kingdom of Great Britain and Northern Ireland, often shortened to the United Kingdom (UK), or just Britain, is a sovereign country in Western Europe. It is a constitutional monarchy of four countries which were once separate: England, Wales, Scotland and Northern Ireland. The UK borders Ireland.
It is part of the United Nations, the Commonwealth of Nations, NATO, the G7, and formerly the European Union. It had the sixth largest economy in the world by nominal GDP in 2019.
About 95 percent of the UK's population are English speakers. 5.5 per cent of the population speak languages brought to the UK as a result of relatively recent immigration.
The UK has many cities. London is the largest city in the UK and is the capital city. There are also other large cities in England such as Birmingham, Manchester, Liverpool, Leeds, Bristol and Newcastle upon Tyne. Scotland has the large cities of Edinburgh and Glasgow. Cardiff and Swansea are in Wales and Derry and Belfast are in Northern Ireland.
Between the 17th and mid 20th-centuries, Britain became a world power. It became a colonial empire that controlled large areas of Africa, Asia, North America and Oceania. 
At its height in 1922, more than 458 million people lived in the British Empire, one-fifth of the Earth's population. Its area was 13,012,000 square miles: almost a quarter of the Earth's land area. The Empire was sometimes called 'the Empire on which the Sun never sets', meaning it is always daytime someplace in the Empire. Many countries left and became independent from the Empire in the 20th century, although Britain keeps links with most countries of its former empire and also still controls fourteen colonies.
History
 Prehistory 
Humans have lived in Britain for almost a million years. They did not live there all the time, probably because the climate was too extreme at times.
Archaeological remains show that the first group of modern people to live in the British Isles were hunter-gatherers after the last ice age ended. The date is not known: perhaps as early as 8000BC but certainly by 5000BC. They built mesolithic wood and stone monuments. Stonehenge was built between 3000 and 1600BC. Celtic tribes arrived from mainland Europe. Britain was a changing collection of tribal areas, with no overall leader. Julius Caesar tried to invade (take over) the island in 55BC but was not able to do so. The Romans successfully invaded in 43AD.
Written history began in Britain when writing was brought to Britain by the Romans. Rome ruled in Britain from 44AD to 410AD. They ruled the southern two-thirds of Great Britain. The Romans never took over Ireland and never fully controlled Scotland, the land north of the valleys of the River Forth and River Clyde. Their northern border varied from time to time and was marked sometimes at Hadrian's Wall (in modern England), sometimes at the Antonine Wall (in modern Scotland).
After the Romans, waves of immigrants came to Britain. Some were German tribes: the Angles, Saxons and Jutes. Others were Celts, like the Scoti, who came to Great Britain from Ireland. English and Scots are Germanic languages. They developed from Old English. This was spoken by the Anglo-Saxons in an area from the River Forth to the River Tamar.
 Middle Ages 
A later wave of immigration was that of the Vikings, during the Early Middle Ages or Viking Age. During the Viking invasion of Britain, they set up their own kingdom in north-western England, which the Anglo-Saxons named the "Danelaw", after the Danes who lived there and controlled the land. Vikings from Scandinavia also controlled most of the islands which are now part of Scotland, including the Outer Hebrides, the Inner Hebrides, and the Northern Isles (the Shetland Islands and the Orkney Islands). 
After a long period when Anglo-Saxon England was split into various kingdoms, it was made into one kingdom by Æthelstan (Athelstan) in 945 AD. In the 13th century, the lands of Wales were unified by force with England by the wars of Edward I of England ("Edward Longshanks").
 Early modern history 
 Union of the Crowns 
There were hundreds of years of fighting between both kingdoms of Great Britain. In 1603, when Queen Elizabeth I of England died, her closest relative was King James VI of Scotland. He became king of England and Ireland as well as the king of Scotland. The kingdoms of England, Ireland, and Scotland had the same monarch ever since. James VI and I was the first to be named "King of Great Britain", and he ordered the design of the Union Jack. The Union Jack has been the British national flag ever since.
 Union of 1707 
In 1707, the Parliaments of England and Scotland agreed on the Treaty of Union, which joined the two countries into one country called the United Kingdom of Great Britain under Queen Anne with the Acts of Union 1707. This union merged Scotland and England into one kingdom. England and Scotland kept their own laws, with English law in England and Wales and Scots law in Scotland. The division between the Church of Scotland and the Church of England continued. Ireland and Great Britain continued to have the same king, but Ireland did not become part of the new kingdom in 1707.
 Modern history 
 Union of 1801 
Scotland and England had already independently had much influence over Ireland since 1200. In 1800 laws were passed in the parliaments of Great Britain and Ireland to merge the two kingdoms and their two parliaments. The country was then called the United Kingdom of Great Britain and Ireland. The Union Jack was changed so that the flag of Saint Patrick (a red saltire) shows Ireland to be a part of the country.
In 1922 much of Ireland became independent from the United Kingdom as the Irish Free State (now called Ireland). However, six northern counties (called Northern Ireland) are part of the United Kingdom. The country was renamed the United Kingdom of Great Britain and Northern Ireland in 1927.
The new Parliament of Northern Ireland set up in the 1920s stopped working in the 1970s, because of The Troubles. However, devolution started again with the Northern Ireland Assembly after the Belfast Agreement (the "Good Friday Agreement") in 1998. Devolution in Scotland and Wales started the Scottish Parliament and the Welsh Parliament the same year.
The United Kingdom was a member state of the European Union (EU) and an older organization, the European Economic Community (EEC), from 1973 until Brexit in 2020.
In September 2024, the United Kingdom became the first G7 country to phase out coal power for electric generation, after 142 years of using the energy source.
Geography
The UK is northwest off the coast of mainland Europe. Around the UK are the North Sea, the English Channel and the Atlantic Ocean. The UK also rules, usually indirectly, a number of smaller places (mostly islands) around the world, which are known as British Overseas Territories. They were once part of the British Empire. Examples are Gibraltar (on the Iberian Peninsula next to the Strait of Gibraltar) and the Falkland Islands (in the south Atlantic Ocean).
In the British Isles, the UK is made up of four different countries: Wales, England and Scotland and Northern Ireland. The capital city of Wales is Cardiff. The capital city of England is London. The capital city of Scotland is Edinburgh and the capital city of Northern Ireland is Belfast. Other large cities in the UK are Birmingham, Glasgow, Leeds, Manchester, Liverpool, Sheffield, Bristol, Leicester, Coventry, Nottingham, Bradford, Newcastle Upon Tyne and Southampton.
The physical geography of the UK varies greatly. England consists of mostly lowland terrain, with upland or mountainous terrain only found north-west of the River Tees-River Exe line. The upland areas include the Lake District, the Pennines, the North York Moors, Exmoor, and Dartmoor. The lowland areas are typically traversed by ranges of low hills, frequently composed of chalk, and flat plains. Scotland is the most mountainous country in the UK and its physical geography is distinguished by the Highland Boundary Fault which goes across the Scottish mainland from Helensburgh to Stonehaven. The Royal Observatory, Greenwich is the defining point of the Prime Meridian.The weather of the United Kingdom is changeable and unpredictable. Summers are moderately warm, winters are cool to cold. Rain falls throughout the year, and more on the west than the east because of its northerly latitude and the warm water from the Atlantic Ocean's Gulf Stream. The usually moderate prevailing winds from the Atlantic may be interrupted by Arctic air from the northeast or hot air from the Sahara.
The United Kingdom is reducing greenhouse gas emissions. It has met the Kyoto Protocol targets. It has signed the Paris Agreement. The British government want the UK to be carbon neutral by the year 2050.
Climate
The United Kingdom has an oceanic climate.
The highest temperature ever recorded in the United Kingdom was 40.3 C F, on 19 July 2022 in Coningsby. The lowest temperature ever recorded was -27.2 C F, on February 11, 1895 & January 10, 1982 in Braemar, and December 30, 1995 in Altnaharra.
Following resumed negotiations a treaty was signed on 22 May 2025 that will formally transfer the sovereignty of the territory to Mauritius once it comes into effect, while the Diego Garcia military base remains under British control during a 99-year lease.
Politics
The United Kingdom is a parliamentary democracy based on a constitutional monarchy. The people of the United Kingdom vote for a members of Parliament to speak for them and to make laws for them. King Charles III is the King of the United Kingdom of Great Britain and Northern Ireland and is the head of state. The government, led by the Prime Minister, governs the country and appoints cabinet ministers. Today, the Prime Minister is Keir Starmer, who is the leader of the centre-left Labour Party.
Parliament is where laws are made. It has three parts: the House of Commons, the House of Lords, and the King. The House of Commons is the most powerful part. It is where Members of Parliament sit.
Scotland has its own devolved Parliament with the power to make laws on things like education, health and Scottish law. Northern Ireland and Wales have their own devolved legislatures which have some powers but less than the Scottish parliament. The Parliament of the United Kingdom is sovereign and it could end the devolved administrations at any time. The UK is a unitary state and not a federation of states.
Parliament
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  Elizabeth II greets NASA GSFC employees, May 8, 2007 edit.jpg
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  Elizabeth II reigned between 1952 until her death in 2022, becoming the longest reigining monarch in UK history. The current monarch is Charles III.
The Parliament of the United Kingdom is the legislature, the political assembly that makes laws and decides tax. The British people are represented by members of parliament (MPs) in the House of Commons of the United Kingdom. MPs are chosen in elections. The MPs in the House of Commons decide who will be the Prime Minister of the United Kingdom. The prime minister decides who will be in the British Government (His Majesty's Government). The government is not controlled by the king or queen, but by Parliament. In Britain, Parliament is made up of the House of Commons and the House of Lords.
Unlike the House of Commons, the people in the House of Lords are not elected. The people who sit in the House of Lords are called peers. Most peers are appointed by the government. There are some who are hereditary peers (who inherit their peerages from ancestors or other family members). Certain bishops in the established Church of England also attend the House of Lords. (The Church of England is the national church in England. The Church of Scotland does not have bishops, and neither Wales nor Northern Ireland has an established national church.) Together, the two houses make a bicameral legislature, in which the House of Commons has more power. In the past, the House of Lords had more power. Before the 20th century, the prime minister was often a member of the House of Lords. As the House of Lords lost its powers, as political reforms tried to improve democracy, the House of Commons became more powerful and the prime minister is now always a member of the House of Commons.
After the English Civil War during the Wars of the Three Kingdoms, Oliver Cromwell became Lord Protector, and the monarchy ended for a time. The British Isles were a republic, which Cromwell named the "Commonwealth of England, Scotland, and Ireland". Although the monarchy was restored after his death, the Crown slowly became the secondary power, and Parliament the first. Until the early twentieth century, only men who owned property could vote to choose MPs. In the nineteenth century, more people were given suffrage. In 1928, all men and women got the vote: this is called universal suffrage.
Almost all members of Parliament belong to political parties. The biggest parties are the Conservative Party, Labour Party, the Scottish National Party and the Liberal Democrats. Members of the same party agree to work together. A party (often with more than half the seats: a majority) forms the government. The leader of the party becomes the prime minister, who then chooses the other ministers. Because the government has a majority in Parliament, it can normally control what laws are passed.
The British Parliament is in Westminster, in London. It has power over the whole of the United Kingdom. Wales, Scotland and Northern Ireland each have their own parliaments as well, and these have more limited powers. England does not have a separate parliament. 
Scotland has the Scottish Parliament at Holyrood in Edinburgh. Wales has the Welsh Parliament in Cardiff. Northern Ireland has the Northern Ireland Assembly at Stormont in Belfast. There are also parliaments in the Isle of Man and in Jersey and Guernsey (the Channel Islands), which are all island states for which the UK has responsibility in international law. Man, Jersey, and Guernsey are "crown dependencies". Some British Overseas Territories have their own legislatures.
 Parts of the UK 
 Countries (nations) 
About 68 million people live in the UK (2022). They can be divided into four big nationalities based on the countries where they live (or where they were born or their ancestry). Each country has a demonym for its people (for example; England's people are English), but no matter which country someone is from, they have a British nationality.
 England is the biggest country, where most people in the UK live. People who live in England are called English. Their native language is called English, which is spoken by most people in England. England's land is split between regions. 
 Scotland, north of England, is the second biggest country. People who live there are called Scottish, and a Scottish person may be called a Scot. Some speak a language other than English: Scottish Gaelic, a Gaelic language. Scottish English, on the other hand, is a version of English. 
 Wales is to the west of England. Its people are called Welsh and they have their own Celtic language which is also called Welsh. Not everyone in Wales can speak Welsh, but almost everyone can speak English.
 Northern Ireland is the smallest country. Unlike the other three countries, it is not on the island of Great Britain: it is part of the island called Ireland. Northern Ireland takes up about a sixth of Ireland (with the Republic of Ireland taking up the remainder). People who live in Northern Ireland are either Irish, British, or Northern Irish. The people who live here speak English.
 Crown dependencies 
The crown dependencies are three nations which are not part of any of the four countries in the UK. They are: the Isle of Man, Jersey and Guernsey. Unlike the four countries, the governments of the crown dependencies have almost full power over the dependencies, with the exception of military and international relations. Everybody from a crown dependency has a British nationality.
 Overseas Territories 
The British Overseas Territories are former colonies of the British Empire which have not become independent from the UK. There are fourteen. Some have civilisations on them while others are military bases. Most of them have their own governments. The UK is responsible for their defence and international relationships. Everybody from an overseas territory has a British nationality.
Military
The United Kingdom has one of the most advanced militaries in the world, alongside such countries such as the USA and France, and operates a large navy (Royal Navy), a sizable army, (British Army) and an air force (Royal Air Force).
From the 18th century to the early 20th century, the United Kingdom was one of the most powerful nations in the world, with a large and powerful navy (due to the fact it was surrounded by sea, so a large navy was the most practical option). This status has faded in recent times, but it remains a member of various military groups such as the UN Security Council and NATO. It is also still seen as a great military power.
Economy
The United Kingdom is a developed country with the sixth-largest economy in the world. It was a superpower during the 18th, 19th and early 20th century and was considered since the early 1800s to be the most powerful and influential nation in the world, in politics, economics and in military strength.
Britain continued to be the biggest manufacturing economy in the world until 1908 and the largest economy until the 1920s. The economic cost of two world wars and the decline of the British Empire in the 1950s and 1960s reduced its leading role in global affairs. The United Kingdom still has strong economic, cultural, military and political influence and is a nuclear power. The United Kingdom holds a permanent seat on the United Nations Security Council, and is a member of the G8, NATO, World Trade Organization and the Commonwealth of Nations. The City of London, in the capital, is famous for being the largest centre of finance in the world.
Literature
William Shakespeare was an English playwright. He did write plays in the late 16th century. Some of his plays were Romeo and Juliet and Macbeth. In the 19th century, Jane Austen and Charles Dickens were novelists. Twentieth-century writers include the science-fiction novelist H. G. Wells and J. R. R. Tolkien. The children's fantasy Harry Potter series was written by J. K. Rowling. Aldous Huxley was also from the United Kingdom.
English language literature is written by authors from many countries. Eight people from the United Kingdom have won the Nobel Prize in Literature. Seamus Heaney is a writer who was born in Northern Ireland.
Arthur Conan Doyle from Scotland wrote the Sherlock Holmes detective novels. He was from Edinburgh. The poet Dylan Thomas brought Welsh culture to international attention.
Education
The nature of education is a devolved matter in Scotland, Wales and Northern Ireland. They have separate, but similar, systems of education with laws that a broad education is required from ages five to eighteen, except for in Scotland where school departure is allowed from the age of sixteen. Pupils attend state funded schools (academy schools, faith schools, grammar schools, sixth form colleges, further education, city technology colleges, studio schools) and other children attend independent fee-paying schools (known as public schools).
There have been universities in Britain since the Middle Ages. The "ancient universities" started at this time and in the Renaissance. They are: the University of Oxford, the University of Cambridge, the University of St Andrews, the University of Glasgow, the University of Aberdeen, and the University of Edinburgh. These are the oldest universities in the English-speaking world.
The University of Cambridge, the University of Oxford, and London universities (University College London, the London School of Economics, King's College London and Imperial College London) collectively form the Golden Triangle of universities in the south-east of England. A broader group of twenty universities form the Russell Group of research universities.
Media
The BBC is an organisation in the United Kingdom. It broadcasts in the United Kingdom and other countries on television, radio and the Internet. The BBC also sells its programs to other broadcasting companies around the world. The organisation is run by a group of twelve governors who have been given the job by the King on the advice of government ministers.
Transport
Road traffic in the United Kingdom drives on the left-hand side of the road (unlike the Americas and most of Europe), and the driver steers from the right-hand side of the vehicle. The road network on the island of Great Britain is extensive, with most local and rural roads having evolved from Roman and Medieval times. Major routes developed in the mid 20th Century were made to the needs of the motor car. The multi-lane high speed motorway (freeway) network was mostly built in the 1960s and 1970s. It links major towns and cities.
The system of rail transport was invented in England and Wales, so the United Kingdom has the oldest railway network in the world. It was built mostly during the Victorian era. At the heart of the network are five long-distance main lines which radiate from London to the major cities and secondary population centres with dense commuter networks and highs-speed lines in the regions. The newest part of the network connects London to the Channel Tunnel from St Pancras station. The system of underground railways in London, known as the Tube, has been copied by many other cities.
Most domestic air travel in the United Kingdom is between London and the major cities in Scotland and the North of England and Belfast. London-Heathrow is the nation’s largest airport and is one of the most important international hubs in the world. Other major airports with principal international service include London-Gatwick, Birmingham, Manchester and Glasgow. An extensive system of ferry networks operates. The Isle of Man and the Channel Islands also have domestic passenger and freight routs.
Languages
Major languages spoken in the United Kingdom other than English include Polish (500,000 approximate number of speakers in the United Kingdom), Eastern Panjabi or Punjabi (471,000), Bengali (400,000), Urdu (400,000), Cantonese (300,000), Greek (200,000), Southwestern Caribbean Creole English (170,000).
Native languages include:
Celtic languages
Brittonic or Bythonic languages
 Welsh
 Cornish
Goidelic or Gaelic languages
 Irish Gaelic
 Scottish Gaelic
 Manx language
Germanic languages
 English
 Scots
 Ulster Scots
Relations with countries and other areas
The UK has foreign relations with many countries.
EU, and the United Kingdom–European Union relations; In 2025, there was a new EU–UK deal, including: a defence and security pact, a fisheries agreement, an agrifood agreement, carbon border taxes, and border security. 
Belarus. The British ambassador was (recalled or) removed by British authorities in 2020; The reason was that (British) authorities were not satisfied with the government of Belarus.
Syria. The British ambassador was (recalled or) removed by British authorities in 2012; The embassy was also closed; The (British) authorities were not satisfied with the government of Syria.
Hong Kong. The UK has foreign relations with some places that are not countries. Hong Kong has an office in London; The trade office is linked (2024) to a case in the justice system in the UK, according to media. The link is supposed to be thru one of the employees of the trade office.


Charles Darwin: Charles Robert Darwin (12 February 1809 – 19 April 1882) was an English naturalist. He is famous for his work on the theory of evolution. Darwin's book On the Origin of Species was published in 1859. In this book, he put forward much evidence that evolution had occurred. He also proposed natural selection as the way evolution had taken place.
Darwin did not know about genetics: he never read the work of Gregor Mendel. Nevertheless, Darwin's explanation of evolution was fundamentally correct. In contrast to Lamarck, Darwin's idea was that the giraffe's neck became longer because those with longer necks survived better. These survivors passed their genes on, and in time the whole species got longer necks.
 Personal life 
Darwin was born in Shrewsbury, Shropshire. His grandfather, Erasmus Darwin, opposed the slave trade; his father was a doctor. He studied at the University of Edinburgh Medical School and at Christ's College, Cambridge. Despite studying medicine at the University of Edinburgh Medical School, a very influential medical school, Darwin dropped out because he hated the sight of blood and was bored of the lectures there. At Cambridge, he created the Gourmet Club, also known as the Glutton Club, where he would eat exotic animals.
In 1843 Darwin, who already had ten children with his wife Emma, bought Down House in the village of Downe, Kent. He lived there for the rest of his life, and today the house and contents are open to the public.
In 1882, he was diagnosed with angina pectoris, which then meant coronary thrombosis. He died at Down House from heart failure caused by coronary thrombosis on 19 April 1882 at the age of 73. His last words were to his family, telling Emma, "I am not the least afraid of deathRemember what a good wife you have been to meTell all my children to remember how good they have been to me". While he rested, he repeatedly told Henrietta and Francis, "It's almost worthwhile to be sick to be nursed by you".
 Voyage of the HMS her majesty's ship Beagle 
Darwin spent almost five years on board a Royal Navy exploring ship, the HMS Beagle. He was the guest naturalist, which meant that he was responsible for making collections and notes about the animals, plants, and the geology of the countries they visited. The ship's crew made charts of all the coastal areas, which could be used by the navy wherever it went in the world. At the time, Britain had by far the largest navy in the world, and an empire which was global.
Darwin collected everywhere the ship landed. He found huge fossils of recently extinct mammals, experienced an earthquake in Chile, and noticed the land had been raised. He knew of raised beaches elsewhere, high in the Andes, with fossil seashells and trees which had once grown on a sandy beach. Obviously the Earth was constantly changing, with land rising in some places, and sinking in others. He collected birds and insects, and sent shipments back to Cambridge for experts to identify.
Darwin was the first dedicated naturalist to visit the Galapagos Islands, off the west coast of Ecuador. He noticed that some of the birds were like mockingbirds on the mainland, but different enough to be placed in separate species. He began to wonder how so many new species came to be on these islands.
When Darwin got back to England, he edited a series of scientific reviews of the voyage, and wrote a personal journal which we know as The Voyage of the Beagle. It is one of the great natural history travel diaries.
 Evolution 
While on the H.M.S. Beagle, and later back home in London, Darwin had come across the ideas of the Rev. T.R. Malthus. Malthus had realised that, although humans could double their population every 25 years, it did not happen in practice. He thought the reason was that a struggle for existence (or resources) limited their numbers. If numbers increased, then famine, wars and diseases caused more deaths. Darwin, who knew that all living things could, in principle, increase their numbers, began to think about why some survived, while others did not.p264-268 His answer took years to develop.
The theory of evolution says that all living things on Earth, including plants, animals and microbes, come from a common ancestor by slowly changing throughout the generations. Darwin suggested that the way living things changed over time is through natural selection. This is the better survival and reproduction of those that best fit their environment. Fitting into the place where you live is called adapting. Those who fit best into the place where they live, the best adapted, have the best chance to survive and breed. Those who are less well-adapted tend not to survive. If they do not survive well enough to raise young, this means they do not pass on their genes. In this way, the species gradually changes.
The first chapter of the Origin deals with domesticated animals, such as cattle and dogs. Darwin reminded readers of the huge changes mankind had made in its domestic animals, which were once wild species. The changes were brought about by selective breeding – choosing animals with desirable characters to breed from. This had been done generation after generation, until our modern breeds were produced. Perhaps what man had done deliberately, might happen in nature, where some would leave more offspring than others.
Darwin noticed that although young plants or animals are very similar to their parents, no two are exactly the same and there is always a range of shape, size, color, and so on. Some of these differences the plant or animal may have got from their own ancestors, but some are new and caused by mutations. When such differences made an organism more able to live in the wild, it would have a better chance to survive, and would pass on its genes to its offspring, and they to their offspring. Any difference that would cause the plant or animal to have less of a chance to live would be less likely to be passed on, and would eventually die out altogether. In this way groups of similar plants or animals (called species) slowly change in shape and form so that they can live more successfully and have more offspring who will survive them. So, natural selection had similarities to selective breeding, except that it would happen by itself, over a much longer time.
He first started thinking about this in 1838, but it took a full twenty years before his ideas became public. By 1844 he was able to write a draft of the main ideas in his notebook. Historians think that he did not talk about his theory because he was afraid of public criticism. He knew his theory, which did not discuss religion, raised questions about the literal truth of the Book of Genesis. Whatever the reason, he did not publish his theory in a book until 1859. In 1858 he heard that another biologist, Alfred Russel Wallace, had the same ideas about natural selection. Darwin and Wallace's ideas were first published in the Journal of the Linnaean Society in London, 1858. Then, Darwin published his book the next year. The name of the book was On the Origin of Species by means of Natural Selection, or the preservation of favored races in the struggle for life. This is usually called The Origin of Species.
 Other works 
Darwin wrote a number of other books, most of which are also very important.
 His books 
 1838-43: Zoology of the voyage of H.M.S. Beagle: published between 1839 and 1843 in five Parts (and nineteen numbers) by various authors, edited and superintended by Charles Darwin, who contributed sections to two of the Parts:
 1838: Part 1 No. 1 Fossil Mammalia, by Richard Owen (Preface and Geological introduction by Darwin)
 1838: Part 2 No. 1 Mammalia, by George Robert Waterhouse (Geographical introduction and A notice of their habits and ranges by Darwin)
 1839: Journal and remarks (The Voyage of the Beagle)
 1842: The structure and distribution of Coral Reefs
 1844: Geological observations of volcanic islands
 1846: Geological observations on South America
 1849: Geology from A manual of scientific enquiry; prepared for the use of Her Majesty's Navy: and adapted for travelers in general. ed. John Herschel.
 1851: A Monograph of the Sub-class Cirripedia, with figures of all the species. The Lepadidae; or, Pedunculated Cirripedes. Living barnacles.
 1854: A Monograph of the Sub-class Cirripedia, with figures of all the species. The Balanidae (or Sessile Cirripedes); the Verrucidae, etc.
 1851: A Monograph on the Fossil Lepadidae, or, Pedunculated Cirripedes of Great Britain. Fossil barnacles.
 1854: A Monograph on the Fossil Balanidæ and Verrucidæ of Great Britain
 1859: On the Origin of Species by means of natural selection, or the preservation of favoured races in the struggle for life
 1862: On the various contrivances by which British and foreign Orchids are fertilised by insects (Fertilisation of orchids)
 1865: On the movements and habits of climbing plants (Linnean Society paper, published in book form in 1875)
 1868: The variation of animals and plants under domestication
 1871: The Descent of Man, and selection in relation to sex
 1872: The expression of emotions in Man and animals
 1875: Insectivorous plants
 1876: The effects of cross and self fertilisation in the vegetable kingdom
 1877: The different forms of flowers on plants of the same species
 1880: The power of movement in plants
 1881: The formation of vegetable mould through the action of worms.
The original manuscript books of the Origin of Species were returned to Cambridge University library in 2020. They were stolen 22 years before.
 His library 
A full list of all the books in his library is now available. The roughly 7,400 titles have been listed by John van Wylie at the National University of Singapore.


Canadian Indian residential school system: Until 1996, Indigenous nb In this article, Indigenous is capitalized because it refers to a specific group of people. The Government of Canada recommends capitalizing the word Indigenous when talking about them, their beliefs, and their communities. children in Canada were forced to go to boarding schools in order to make them assimilate into white Canadian society. The Indian nb Indian is an outdated term that is not used anymore. It has been replaced by First Nations, Métis, and Inuit. For the purposes of this article and to discuss the history of these schools, the term "Indian" is used only when talking about specific quotes and laws. residential school system refers to the group of these schools for First Nations children. These schools were run by Christian churches and got money from the Canadian government. These schools existed for over 100 years and more than 150,000 children were in them. Of these children, at least 3,200 died.
Many residential schools were started when the Indian Act was passed in 1876. In 1896, a change was made to the Act so that all First Nations children had to go to school. A lot of their communities were located far away from schools, so they had to go to residential schools and live there for the school year. These schools were usually very far away from their families in order to encourage them to assimilate. There were residential schools in every province and territory except for New Brunswick and Prince Edward Island.
At these schools, these children were forced to give up their cultures. They were given new names and were not allowed to speak their mother tongues or visit their families. They were abused at these schools and were not treated well. When these children graduated from these schools, they did not fit into their Indigenous communities or into mainstream Canadian society. They did not learn the skills needed to survive off the land. At the same time, these schools did not teach them how to skills on how to live in cities or stop the students from becoming victims of racism. Studies have shown that these students and their children and grandchildren are more likely to have problems such as PTSD, alcoholism, drug use, and suicide than kids who did not go to residential schools.
In 2008, Prime Minister Stephen Harper apologized to the survivors of the residential schools on behalf of the Canadian government. The government also set up the Truth and Reconciliation Commission (TRC) in order to learn the truth about what happened at these schools. Many survivors came and talked about their experiences. In 2015, the TRC published a report that said the residential school system was cultural genocide.
 History 
Ever since Europeans arrived in North America, they have been trying to teach the native peoples there about European ways. The discovery doctrine that Europeans believed said that it was OK to colonize the land because the people they found were not Christian and were "uncivilized." They thought it was their duty to teach others about Christianity and civilization.
French missionaries started schools for Indigenous people in the 17th century. However, they stopped because making Indigenous people unhappy was not good for the fur trade.
In the 1820s, English missionaries started schools in what is now Manitoba and Ontario. Unlike the French schools, they taught Protestantism.
The Canadian government became interested in starting schools for Indigenous people because they were no longer allies in war. Instead, they were seen as nuisances because many of them moved around as nomads and didn't practice agriculture. The Department of Indian Affairs (DIA) partnered up with the churches to start putting more Indigenous children into the residential schools and "get rid of the Indian problem" by converting them to Christianity and bringing them into European-Canadian society. The government provided the buildings and money while the church provided the teachers and staff.
Of the schools run by churches, most of them were run by the Catholic Church. Other schools were run by the Anglican Church, the United Church of Canada, and the Presbyterian Church.
 Life in Residential Schools 
The students at the schools were treated bad by the teachers and staff. They were beaten up and sexually abused. The teachers believed that beating up the students helped to save their souls and stop them from running away. It was bad for a school if students ran away because they were responsible if a student died while running away. Students were malnourished. The schools were crowded, dirty, cold, and didn't have good medical care. That meant that a lot of students ended up getting tuberculosis.
 Teaching style 
In the residential schools, students learned the same way that European kids were taught. This was very different from how First Nations people taught their kids. The Indigenous people used a "look, listen, learn" method of education that did not involve classrooms or books. Instead, they taught their kids through games, stories, and ceremonies. The kids struggled with book-learning because that was not how their parents taught them. They were also forced to speak English and French. Sometimes, they were beaten up if they spoke in their native languages.
 Resistance 
The residential schools didn't meet their goal in extinguishing Indigenous cultures. In some cases, students burned down the schools.


Soviet Union: The Union of Soviet Socialist Republics. (USSR),. simply known as the Soviet Union, was a transcontinental country that spanned much of Eurasia from 1922 to 1991. It was the first country to declare itself socialist and build towards a communist society. It was a union of 14 Soviet socialist republics and one Russian Soviet Federative Socialist Republic (Russian SFSR).
The Soviet Union was created about five years after the Russian Revolution. In which the Russian Empire was destroyed after years of fighting in World War I. It was announced after Vladimir Lenin overthrew Alexander Kerensky as Russian leader. The communist government developed from an agriculture based economy to an industry one, and over time became a major, powerful union. The largest country in the Union was Russian SFSR, Kazakh SSR was the second, and Ukrainian SSR the third largest. The capital city of the Soviet Union and RSFSR was Moscow. The Soviet Union expanded its political control greatly after World War II. It took over the whole of Eastern Europe. Those countries were not made part of the Soviet Union, but they were controlled by the Soviet Union indirectly. These countries, like Poland, Czechoslovakia, Hungary, Bulgaria, Romania and East Germany, were called satellite states which each helped the USSR during World War II.
The top-level committee which made the laws was the Supreme Soviet of the Soviet Union. In practice, the General Secretary of the Communist Party of the Soviet Union was the leader and most important decision-maker in their system of government. Although the constitution said the Republics could leave the Union if they wanted, it was a completely centralized government, with no states' rights for the member countries.
The USSR was formed with the idea to give everyone equal social and economic equality. There was virtually no private property and everything belonged to the state including public property was an idea discussed by Karl Marx, and formed the ideology of socialism of 'Soviets', or workers' councils, were created by the working class to lead the socialist state democratically, but they soon lost power with the rise of Stalinism. 
The Union was successful in many fields, putting the first man, first woman, and first satellite into space, defeating Hitler's Nazi Germany invasion and winning World War II, together with the United States and United Kingdom, helping build infrastructure, as well as schools and hospitals in many third-world countries. However, its centralized government found innovation and the changes were difficult to handle. The USSR collapsed in 1991 due to the failed efforts to reform the country by its 8th Leader and the 10th president, Mikhail Gorbachev, leaving behind Russian Federation in its place along with 14 other nations.
 Holidays 
 Republics of the Soviet Union 
The Soviet Union consisted of 15 republics. These were either Soviet Socialist Republics, or Soviet Socialist Federal Republics. Each republic was independent and handled its own cultural affairs. Each also had the right to leave the union, which they did in 1989.
The Federal Republics were different in that they had more autonomy, and were made up of states themselves. These were often called Autonomous Soviet Socialist Republics. There were a number of them. Most of them still exist; though they are now republics, within the independent state. The Tatar ASSR turned into the Republic of Tatarstan, for example (It is located around Kazan).
 Soviet republics (1922–1989) 
Armenian SSR (Soviet Socialist Republic)
 Azerbaijan SSR
 Byelorussian SSR
 Estonian SSR
 Georgian SSR
 Kazakh SSR
 Kyrgyz SSR
 Latvian SSR
 Lithuanian SSR
 Moldavian SSR
 Russian SFSR (Soviet Federal Socialist Republic)
 Tajik SSR
 Turkmen SSR
 Ukrainian SSR
 Uzbek SSR
Karelo-Finnish SSR (1940-1956)
 Independent countries (1989–present) 
 Armenia
 Azerbaijan
 Belarus
 Estonia
 Georgia
 Kazakhstan
 Kyrgyzstan
 Latvia
 Lithuania
 Moldova
 Russia
 Tajikistan
 Turkmenistan
 Ukraine
 Uzbekistan
N/A (Karelia is a republic of Russia)
 Geography, climate and environment 
The Soviet Union at its largest size in 1991, with 22400000 km2, was the world's biggest country. Covering a sixth of the world's land, its total size was comparable to North America's. The western part (in Europe) accounted for a quarter of the country's area, and was the country's cultural and economic center. The eastern part (in Asia) extended to the Pacific Ocean to the east and Afghanistan to the south, and was much less lived in than the western part. It was over 10000 km across (11 time zones) and almost 7200 km north to south. Its five climatic (different weather, temperature, humidity and atmospheric pressure) zones were tundra, taiga, steppes, desert, and mountains.
The Soviet Union had the world's longest border, measuring over 60000 km in 1991. Two thirds of the Soviet border was coastline of the Arctic Ocean. Across the Bering Strait was the United States. The Soviet Union bordered Afghanistan, China, Czechoslovakia, Finland, Hungary, Iran, Mongolia, North Korea, Norway, Poland, Romania, and Turkey at the end of WWII.
The Soviet Union's (and now Russia's) longest rivers are the Yenisey, Ob/Irtysh, Amur and Lena. The Soviet Union's highest mountain was Communism Peak (today it is called the Ismoil Somoni Peak) in Tajikistan measured at 7495 m. The world's largest lake, the Caspian Sea, was mostly in the Soviet Union. as well as the world's deepest lake, Lake Baikal.
 History 
The last Russian Tsar (emperor), Nicholas II, ruled Russia until March 1917, when the Russian Empire was taken over and a short-lived "provisional government" replaced it, led by Alexander Kerensky and soon to be overthrown in November by Bolsheviks and started the Russian civil war.
From 1917 to 1922, the country that came before the Soviet Union was the Russian Soviet Federative Socialist Republic (RSFSR), which was its own country, as were other Soviet republics at the time. The Soviet Union was officially created in December 1922 as the union of the Russian (also known as Bolshevist Russia), Ukrainian, Byelorussian, and Transcaucasian Soviet republics ruled by the communist Bolshevik parties.
 Revolution and the foundation 
Extreme government-changing activity in the Russian Empire began with the Decembrist Revolt of 1825, and although serfdom was removed in 1861, its removal was achieved on terms unfavorable to the peasants (poor agricultural workers) and served to encourage changers (revolutionaries). A parliament (legislative assembly)—the State Duma—was created in 1906 after the Russian Revolution of 1905, but the Tsar suppressed people trying to move from absolute to constitutional monarchy. Rebellion continued and was aggravated during World War I by failure and food shortages in popular cities.
A rebellion in Petrograd, in response to the wartime decay of Russia's economy and morale, caused the "February Revolution" and the removal of the government in March 1917. The tsarist autocracy was replaced by the Russian "Provisional government", whose leaders intended to have elections to Russian Constituent Assembly and to continue war on the side of the Entente in World War I.
At the same time, workers' councils, known as Soviets, sprang up across the country. The Bolsheviks, led by Vladimir Lenin, pushed for socialist revolution in the Soviets and on the streets. In November 1917, during the "October Revolution", they took power from the Provisional Government. In December, the Bolsheviks signed an armistice (peace) with the Central Powers. In March, after more fighting, the Soviets quit the war for good and signed the Treaty of Brest-Litovsk.
In the long and bloody Russian Civil War, the new Soviet power won. The civil war between the Reds and the Whites started in 1917 and ended in 1923. It included the Siberian Intervention and other foreign interference, the killing of Nicholas II and his family and the famine in 1921, which killed about 5 million. In March 1921, during a related conflict with Poland, the Peace of Riga was signed and split disputed territories in Belarus and Ukraine between the Republic of Poland and Soviet Russia. The Soviet Union had to resolve similar conflicts with the newly established Republic of Finland, the Republic of Estonia, the Republic of Latvia, and the Republic of Lithuania, which had all escaped the empire during the civil war.
Unification of the Soviet Republics
On 28 December 1922, people from the Russian SFSR, the Transcaucasian SFSR, the Ukrainian SSR, and the Byelorussian SSR approved the Treaty of Creation of the USSR and the Declaration of the Creation of the USSR, creating the Union of Soviet Socialist Republics. These two documents were made true by the 1st Congress of Soviets of the USSR and signed by heads of delegations.
On 1 February 1924, the USSR was accepted as a country by the British Empire. Also in 1924, a Soviet Constitution (set of laws) was approved, making true the December 1922 union of the Russian SFSR, the Ukrainian SSR, the Belarusian SSR, and the Transcaucasian SFSR to form the "Union of Soviet Socialist Republics" (USSR).
The big changes of the economy, industry, and politics of the country began in the early days of Soviet power in 1917. A large part of this was performed according to Bolshevik Initial Decrees, documents of the Soviet government, signed by Vladimir Lenin. One of the most important and notable breakthroughs was the GOELRO plan, that planned a major change of the Soviet economy based on total electrification of the country. The Plan was developed in 1920 and covered a 10- to 15-year period. It included the making of a network of 30 regional power stations, including ten large hydroelectric power plants, and numerous electric-powered large industrial organizations. The Plan became the prototype for subsequent Five-Year Plans and was basically fulfilled by 1931.
 Stalin's rule 
From its beginning years, government in the Soviet Union was ruled as a one-party state by the Communist Party (Bolsheviks). After the economic policy of War Communism during the Civil War, the Soviet government permitted some private enterprise to coexist with nationalized industry in the 1920s and total food requisition in the countryside was replaced by a food tax (see New Economic Policy).
Soviet leaders argued that one-party rule was necessary because it ensured that 'capitalist exploitation' would not return to the Soviet Union and that the principles of Democratic Centralism would represent the people's will. Debate over the future of the economy provided the background for Soviet leaders to take more power in the years after Lenin's death in 1924. Initially, Lenin was to be replaced by a "troika" composed of Grigory Zinoviev of Ukraine, Lev Kamenev of Moscow, and Joseph Stalin of Georgia.
Stalin led the country through World War II and into the Cold War. Gulag camps greatly expanded to take a lot of prisoners. After he died, Georgy Malenkov briefly continued his policies. Nikita Khrushchev reversed some of Stalin's policies,but Leonid Brezhnev and Alexei Kosygin kept things as they were.
After the 1936 revised constitution, the Soviet Union stopped acting as a union of republics and more as a single super-country.
 Khrushchev era 
Stalin died on 5 March 1953. Nikita Khrushchev eventually won the following power struggle by the mid-1950s. In 1956, he denounced Stalin's repression and eased controls over party and society. This was known as de-Stalinization.
Moscow considered Eastern Europe to be a very vital buffer zone for the forward defense of its western borders. For this reason, the USSR sought to strengthen its control of the region. It did this by transforming the Eastern European countries into satellite states, dependent upon and obedient to its leadership. Soviet military force was used to suppress anti-Stalinist uprisings in Hungary and Poland in 1956.
During the Khrushchev’s power program of relocating every urban family to a separate apartment was started. There were built a lot of 5-floor buildings to live for 20 years. 
After Krushchev’s visit to the USA, corn became very popular in the USSR.
In the late 1950s, a confrontation with China regarding the USSR's policies led to the Sino–Soviet split. This resulted in a break throughout the global Marxist–Leninist movement. The governments in Albania, Cambodia and Somalia chose to ally with China instead of the USSR.
During this period of the late 1950s and early 1960s, the Soviet Union continued to make progress in the Space Race. It rivalled the United States. The USSR launched the first artificial satellite, Sputnik 1 in 1957; a living dog named Laika in 1957; the first human being, Yuri Gagarin in 1961; the first woman in space, Valentina Tereshkova in 1963; Alexei Leonov, the first person to walk in space in 1965; the first soft landing on the Moon by spacecraft Luna 9 in 1966; and the first Moon rovers, Lunokhod 1 and Lunokhod 2.
 Leonid Brezhnev 
Leonid Brezhnev led the Soviet Union from 1964 until his death in 1982. He came to power after he convinced the government to overthrow the then-leader Nikita Krushchev. Brezhnev's rule is often linked with the decline in Soviet economy and starting the chain of events that would lead to the union's eventual collapse. He had many self-awarded medals. He was awarded Hero of the Soviet Union (the highest honor) on three separate occasions. Brezhnev was succeeded by Yuri Andropov, who died a few years later. Andropov was succeeded by the frail and aging Konstantin Chernenko. Chernenko died a mere year after taking office.
In 1980 the Soviet Union hosted the Summer Olympics with Brezhnev opening and closing the games. The games were heavily boycotted by the western nations, particularly the United States. During the closing ceremony, the flag of the City of Los Angeles was raised instead of the flag of the United States (to symbolise the next host city/nation) and the anthem of the Olympics was played instead of the anthem of the United States in response to the boycott.
Brezhnev was the second longest serving Soviet leader after Stalin. The following is a list of leaders (General Secretary of the Communist Party) in order of their tenure and length of leadership:
 Vladimir Lenin 1922-1924 (2 years)
 Leon Trotsky 1924-1927 (3 years failed)
 Joseph Stalin 1924-1953 (29 years)
 Lavrenty Beria 1953 (failed March-June 1953)
 Vyacheslav Molotov 1953-1956 (3 years)
 Georgy Malenkov 1953-1955 (1 year and a half)
 Nikita Khrushchev 1953-1964 (11 years)
 Leonid Brezhnev 1964-1982 (18 years)
 Yuri Andropov 1982-1984 (2 years)
 Konstantin Chernenko 1984-1985 (1 year)
 Mikhail Gorbachev 1985-1991 (6 years)
Khrushchev and Gorbachev are the only Soviet leaders to have not died whilst in office. Lenin, Stalin and Khrushchev are the only leaders who were not (de jure) head of state during their leaderships.
Gorbachev's rule
Mikhail Gorbachev was the Soviet Union's last leader. He was the only Soviet leader to have been born after the October revolution and was thus a product of the Soviet Union having grown up in it. He and US president Ronald Reagan signed a treaty to get rid of some nuclear weapons. Gorbachev started social and economic reforms named Perestroika that gave people freedom of speech; which allowed them to criticize the government and its policies. The ruling communist party lost its grip on the media and the people. Newspapers began printing the many failures that the Soviet Union had covered up and denied in its past. The Soviet Union's economy was lagging and the government was spending a lot of money on competing with the west.
 Dissolution 
By the 1980s the Soviet economy was suffering but it was stable. Gorbachev's new ideas had gotten out of hand and the communist party lost control. Boris Yeltsin was elected (democratically) the President of the Russian SFSR even though Gorbachev did not want him to come into power. Lithuania announced its independence from the Union and the Soviet government demanded it surrender its independence or it would send the Red Army to keep order. Gorbachev invented the idea of keeping the Soviet Union together with each republic being more independent but under the same leader. He wanted to call it the 'Union of Soviet Sovereign Republics' to keep the Russian initials as CCCP (USSR in English).
A group of communist leaders, unhappy with Gorbachev's idea, tried to take over Moscow and stop the Soviet Union from collapsing. It only made people want independence more. Although he survived the attempted takeover, he lost all of his power outside of Moscow. Russia declared independence in December 1991. Later in the month, leaders of Russia, Byelorussia, and Ukraine signed a treaty called the Belavezha Agreement to dissolve the USSR, extremely angering Gorbachev. He had no choice but to accept the treaty and resigned on Christmas Day 1991. The Soviet Union's parliament (Supreme Soviet) made the Belavezha Agreement law, marking formally the dissolution of the Soviet Union. The next day, the Soviet flag was lowered from the Kremlin for the last time.
Since 2013, the document that confirmed the dissolution of the Soviet Union has been missing.
 Sports 
Made on July 20th, 1924, in Moscow, Sovetsky Sport was the first sports newspaper of the Soviet Union. Sports in the Soviet Union were highly prioritized and tightly controlled. The government invested heavily in athletic programs to showcase Soviet superiority. Success in sports was seen as a reflection of the political system's strength. The emphasis on Olympic success led to the development of talented athletes in various disciplines. However, it also involved state-sponsored doping programs, which became a controversial legacy.
 Culture 
The culture of the Soviet Union went through several stages during the USSR's existence. During the first 10 years following the revolution, there was freedom and artists tested several different styles to find a distinctive Soviet style of art. Lenin wanted art to be available to the Russian people. On the other hand, hundreds of smart people, writers, and artists were killed, and their work not being available to anyone, such as Nikolay Gumilyov who was shot, for conspiring against the Bolshevik regime, without proof.
During Stalin's rule, the Soviet culture was described by the rise of the government-forced style of socialist realism, with all other trends being severely repressed, with rare exceptions, such as Mikhail Bulgakov's works. Many writers were put in prison and killed.
Following the Khrushchev Thaw, censorship was removed. During this time, a different period of Soviet culture developed, described by public life and an intense focus on personal life. Bigger testing in art forms was again allowed, resulting in the creation of better, important work. Underground dissident literature, known as samizdat, was made during this late period. In architecture, the art or practice of designing and constructing buildings, the Khrushchev era mostly focused on functional design as opposed to the highly decorated style of Stalin's epoch. In music, in response to the increasing popularity of forms of popular music like jazz in the West, many jazz orchestras were permitted throughout the USSR, notably the Melodiya Ensemble, named after the principle record label in the USSR.
In the second half of the 1980s, Gorbachev's policies of perestroika and glasnost significantly grew freedom of expression in the country in the media and the press.
 List of wars 
Russian Civil War (1918-1923)
Polish–Soviet War (1918-1921)
Soviet-Japanese Border Conflicts (1932-1939)
Winter (Soviet-Finnish) War (1939-1940)
Great Patriotic War of the Soviet Union (the part of the World War II)
Eastern Front (World War II) (1941-1945)
Soviet-Japanese War (1945)
Korean War (1950-1953)
Soviet-Afghan War (1979-1989)


Albert Einstein: May 2019
Albert Einstein (14 March 1879 – 18 April 1955) was a German-American Jewish scientist. He worked on theoretical physics. He developed the theory of relativity. He won the Nobel Prize in Physics in 1921 for theoretical physics.
His most famous equation is in which E is for Energy, m for mass, c is the speed of light is therefore Energy equals mass multiplied by the speed of light squared.
At the start of his career, Einstein didn't think that Newtonian mechanics was enough to bring together the laws of classical mechanics and the laws of the electromagnetic field. Between 1902 and 1909 he made the theory of special relativity to fix it.
Einstein also thought that Isaac Newton's idea of gravity was not completely correct. So, he extended his ideas on special relativity to include gravity. In 1916, he published a paper on general relativity with his theory of gravitation.
In 1933, Einstein was visiting the United States but in Germany, Adolf Hitler and the Nazis came to power (this is before World War II). Since Einstein was Jewish, he did not go back to Germany because of Hitler’s anti-Semitic laws. He lived in the United States and became an American citizen in 1940. On the beginning of World War II, he and Leó Szilárd sent a letter to President Franklin D. Roosevelt explaining to him that Germany was in the making an Atomic bomb; so Einstein and Szilard recommended that the U.S. should also make one. This led to the Manhattan Project, and the U.S. became the first nation in history to create and use the atomic bomb (not on Germany but on Japan). Einstein and other physicists like Richard Feynman who worked on the Manhattan Project later regretted that the bomb was used on Japan.
Einstein lived in Princeton and was one of the first members invited to the Institute for Advanced Study, where he worked for the rest of his life.
He is now thought to be one of the greatest scientists of all time.
His contributions helped lay the foundations for all modern branches of physics, including quantum mechanics and relativity.
 Life 
 Early life 
Einstein was born in Ulm, Württemberg, Germany, on 14 March 1879. His family was Jewish, but was not very religious. However, later in life Einstein became very interested in his Judaism. Einstein did not begin speaking until he was 4 years old. According to his younger sister, Maja, "He had such difficulty with language that those around him feared he would never learn". When Einstein was around 4 years old, his father gave him a magnetic compass. He tried hard to understand how the needle could seem to move itself so that it always pointed north. The needle was in a closed case, so clearly nothing like wind could be pushing the needle around, and yet it moved. So in this way Einstein became interested in studying science and mathematics. His compass gave him ideas to explore the world of science.
When he became older, he went to school in Switzerland. After he graduated, he got a job in the patent office there. While he was working there, he wrote the papers that first made him famous as a great scientist.
Einstein married with a 20-year-old Serbian woman Mileva Marić in January 1903.
In 1917, Einstein became very sick with an illness that almost killed him, fortunately he survived. His cousin Elsa Löwenthal nursed him back to health. After this happened, Einstein divorced Mileva on 14 February 1919, and married Elsa on 2 June 1919.
 Children 
Einstein's first daughter was Lieserl Einstein. She was born in Novi Sad, Vojvodina, Austria-Hungary on January 27, 1902. She spent her first years in the care of Serbian grandparents because her father Albert did not want her to be brought to Switzerland, where he had a job offer at the patent office. Some historians believe she died from scarlet fever.
Einstein's two sons were Hans Albert Einstein and Eduard Tete Einstein. Hans Albert was born in Bern, Switzerland in May 1904. He became a professor in Berkeley (California). Eduard was born in Zürich, Switzerland in July 1910. He died at 55 years old of a stroke in the Psychiatric University Hospital Zurich "Burghölzli" . He had spent his life in and out of hospitals due to his schizophrenia.
 Later life 
In spring of 1914, he moved back to Germany, and became ordinary member of the Prussian Academy and director of a newly established institute for physics of the Kaiser-Wilhelm-Gesellschaft. He lived in Berlin and finished the General Theory of Relativity in November 1915. In the Weimar Republic, he was politically active for socialism and Zionism. In 1922, he received the Nobel prize for Physics for his explanation of the photoelectric effect in 1905. He then tried to formulate a general field theory uniting gravitation and electromagnetism, without success. He had reservations about the quantum mechanics invented by Heisenberg (1925) and Schrödinger (1926). In spring of 1933, Einstein and Elsa were traveling in the US when the Nazi party came to power. The Nazis were violently antisemitic. They called Einstein's relativity theory "Jewish physics," and some German physicists started polemics against his theories. Others, like Planck and Heisenberg, defended Einstein.
After their return to Belgium, considering the threats from the Nazis, Einstein resigned from his position in the Prussian Academy in a letter from Oostende. Einstein and Elsa decided not to go back to Berlin and moved to Princeton, New Jersey in the United States, and in 1940 he became a United States citizen.
Before World War II, in August 1939, Einstein at the suggestion of Leó Szilárd wrote to the U.S. president, Franklin D. Roosevelt, to say that the United States should invent an atomic bomb so that the Nazi government could not beat them to the punch. He signed the letter. However, he was not part of the Manhattan Project, which was the project that created the atomic bomb.
Einstein, a Jew but not an Israeli citizen, was offered the presidency in 1952 but turned it down, stating "I am deeply moved by the offer from our State of Israel, and at once saddened and ashamed that I cannot accept it." Ehud Olmert was reported to be considering offering the presidency to another non-Israeli, Elie Wiesel, but he was said to be "very not interested".
He did his research on gravitation at the Institute for Advanced Study at Princeton, New Jersey until his death on 18 April 1955 of a burst aortic aneurysm. He was still writing about quantum physics hours before he died.
He was awarded the Nobel Prize in Physics.
 Photoelectric effect 
In 1905 he came up with a theory that light was made of small particles called photons Einstein referred to photons as light quant in his paper. Using this theory he was able to explain the photoelectric effect. The formula relating the energy and frequency of a photon is . This means that higher frequency light has more energy per photon.
The photoelectric effect happens when light shining on a metal surface causes it to emit electrons. The difficulty for the classical wave theory was to explain why this effect only seems to occur for high frequency light such as UV, but not lower frequency such as red or infrared.
Einstein showed that, since higher frequency light has photons with more energy, it has a greater chance of forcing electrons out of the metal.
Einstein was also able to explain other phenomena with photons, such as fluorescence and ionization. In 1921 he was awarded the Nobel Prize for this discovery.
 Theory of relativity 
The theory of special relativity was published by Einstein in 1905, in the paper On the Electrodynamics of Moving Bodies. It says that both distance measurements and time measurements change near the speed of light. This means that as one get closer to the speed of light (nearly 300,000 kilometres per second), lengths appear to get shorter, and clocks tick more slowly. Einstein said that special relativity is based on two ideas. The first is that the laws of physics are the same for all observers that are not moving in relation to each other.
Things going in the same direction at the same speed are said to be in an inertial frame.
People in the same "frame" measure how long something takes to happen. Their clocks keep the same time. But in another "frame" their clocks move at a different rate. The reason this happens is as follows. No matter how an observer is moving, if he measures the speed of the light coming from that star it will always be the same number.
Imagine an astronaut were all alone in a different universe. It just has an astronaut and a spaceship. Is he moving? Is he standing still? Those questions do not mean anything. Why? Because when we say we are moving we mean that we can measure our distance from something else at various times. If the numbers get bigger we are moving away. If the numbers get smaller we are moving closer. To have movement you must have at least two things. An airplane can be moving at several hundred kilometers per hour, but passengers say, "I am just sitting here."
Suppose some people are on a spaceship and they want to make an accurate clock. At one end they put a mirror, and at the other end they put a simple machine. It shoots one short burst of light toward the mirror and then waits. The light hits the mirror and bounces back. When it hits a light detector on the machine, the machine says, "Count = 1," it simultaneously shoots another short burst of light toward the mirror, and when that light comes back the machine says, "Count = 2." They decide that a certain number of bounces will be defined as a second, and they make the machine change the seconds counter every time it has detected that number of bounces. Every time it changes the seconds counter it also flashes a light out through a porthole under the machine. So somebody outside can see the light flashing every second.
Every grade school child learns the formula d=rt (distance equals rate multiplied by time). We know the speed of light, and we can easily measure the distance between the machine and the mirror and multiple that to give the distance the light travels. So we have both d and r, and we can easily calculate t. The people on the spaceship compare their new "light clock" with their various wrist watches and other clocks, and they are satisfied that they can measure time well using their new light clock.
Now this spaceship happens to be going very fast. They see a flash from the clock on the space ship, and then they see another flash. Only the flashes do not come a second apart. They come at a slower rate. Light always goes at the same speed, d = rt. That is why the clock on the spaceship is not flashing once a second for the outside observer.
Special relativity also relates energy with mass, in Albert Einstein's E=mc2 formula.
 Mass-energy equivalence 
E=mc2, also called the mass-energy equivalence, is one of the things that Einstein is most famous for. It is a famous equation in physics and math that shows what happens when mass changes to energy or energy changes to mass. The "E" in the equation stands for energy. Energy is a number which you give to objects depending on how much they can change other things. For instance, a brick hanging over an egg can put enough energy onto the egg to break it, but a feather can not.
There are three basic forms of energy: potential energy, kinetic energy, and rest energy. Two of these forms of energy can be seen in the examples given above, and in the example of a pendulum.
A cannonball hangs on a rope from an iron ring. A horse pulls the cannonball to the right side. When the cannonball is released it will move back and forth as diagrammed. It would do that forever except that the movement of the rope in the ring and rubbing in other places causes friction, and the friction takes away a little energy all the time. If we ignore the losses due to friction, then the energy provided by the horse is given to the cannonball as potential energy. (It has energy because it is up high and can fall down.) As the cannonball swings down it gains more and more speed, so the nearer the bottom it gets the faster it is going and the harder it would hit you if you stood in front of it. Then it slows down as its kinetic energy is changed back into potential energy. "Kinetic energy" just means the energy something has because it is moving. "Potential energy" just means the energy something has because it is in some higher position than something else.
When energy moves from one form to another, the amount of energy always remains the same. It cannot be made or destroyed. This rule is called the "conservation law of energy". For example, when you throw a ball, the energy is transferred from your hand to the ball as you release it. But the energy that was in your hand, and now the energy that is in the ball, is the same number. For a long time, people thought that the conservation of energy was all there was to talk about.
When energy transforms into mass, the amount of energy does not remain the same. When mass transforms into energy, the amount of energy also does not remain the same. However, the amount of matter and energy remains the same. Energy turns into mass and mass turns into energy in a way that is defined by Einstein's equation, E = mc2.
The "m" in Einstein's equation stands for mass. Mass is the amount of matter there is in some body. If you knew the number of protons and neutrons in a piece of matter such as a brick, then you could calculate its total mass as the sum of the masses of all the protons and of all the neutrons. (Electrons are so small that they are almost negligible.) Masses pull on each other, and a very large mass such as that of the Earth pulls very hard on things nearby. You would weigh much more on Jupiter than on Earth because Jupiter is so huge. You would weigh much less on the Moon because it is only about one-sixth the mass of Earth. Weight is related to the mass of the brick (or the person) and the mass of whatever is pulling it down on a spring scale – which may be smaller than the smallest moon in the solar system or larger than the Sun.
Mass, not weight, can be transformed into energy. Another way of expressing this idea is to say that matter can be transformed into energy. Units of mass are used to measure the amount of matter in something. The mass or the amount of matter in something determines how much energy that thing could be changed into.
Energy can also be transformed into mass. If you were pushing a baby buggy at a slow walk and found it easy to push, but pushed it at a fast walk and found it harder to move, then you would wonder what was wrong with the baby buggy. Then if you tried to run and found that moving the buggy at any faster speed was like pushing against a brick wall, you would be very surprised. The truth is that when something is moved then its mass is increased. Human beings ordinarily do not notice this increase in mass because at the speed humans ordinarily move the increase in mass is almost nothing.
As speeds get closer to the speed of light, then the changes in mass become impossible not to notice. The basic experience we all share in daily life is that the harder we push something like a car the faster we can get it going. But when something we are pushing is already going at some large part of the speed of light we find that it keeps gaining mass, so it gets harder and harder to get it going faster. It is impossible to make any mass go at the speed of light because to do so would take infinite energy.
Sometimes a mass will change to energy. Common examples of elements that make these changes we call radioactivity are radium and uranium. An atom of uranium can lose an alpha particle (the atomic nucleus of helium) and become a new element with a lighter nucleus. Then that atom will emit two electrons, but it will not be stable yet. It will emit a series of alpha particles and electrons until it finally becomes the element Pb or what we call lead. By throwing out all these particles that have mass it has made its own mass smaller. It has also produced energy.
In most radioactivity, the entire mass of something does not get changed to energy. In an atomic bomb, uranium is transformed into krypton and barium. There is a slight difference in the mass of the resulting krypton and barium, and the mass of the original uranium, but the energy that is released by the change is huge. One way to express this idea is to write Einstein's equation as:
E = (muranium – mkrypton and barium) c2
The c2 in the equation stands for the speed of light squared. To square something means to multiply it by itself, so if you were to square the speed of light, it would be 299,792,458 meters per second, times 299,792,458 meters per second, which is approximately 
(3•108)2 =
(9•1016 meters2)/seconds2=
90,000,000,000,000,000 meters2/seconds2
So the energy produced by one kilogram would be:
E = 1 kg • 90,000,000,000,000,000 meters2/seconds2
E = 90,000,000,000,000,000 kg meters2/seconds2
or
E = 90,000,000,000,000,000 joules
or
E = 90,000 terajoule
About 60 terajoules were released by the atomic bomb that exploded over Hiroshima. So about two-thirds of a gram of the radioactive mass in that atomic bomb must have been lost (changed into energy), when the uranium changed into krypton and barium.
 BEC 
The idea of a Bose-Einstein condensate came out of a collaboration between S. N. Bose and Prof. Einstein. Einstein himself did not invent it but, instead, refined the idea and helped it become popular.
 Zero-point energy 
The concept of zero-point energy was developed in Germany by Albert Einstein and Otto Stern in 1913. It is the lowest possible energy a quantum mechanical system can have, even at absolute zero temperature. It's the energy that remains in a system due to inherent quantum fluctuations and cannot be reduced further.
 Momentum, mass, and energy 
In classical physics, momentum is explained by the equation:
p = mv
where
p represents momentum
m represents mass
v represents velocity (speed)
When Einstein generalized classical physics to include the increase of mass due to the velocity of the moving matter, he arrived at an equation that predicted energy to be made of two components. One component involves "rest mass" and the other component involves momentum, but momentum is not defined in the classical way. The equation typically has values greater than zero for both components:
E2 = (m0c2)2 + (pc)2
where
E represents the energy of a particle
m0 represents the mass of the particle when it is not moving
p represents the momentum of the particle when it is moving
c represents the speed of light.
There are two special cases of this equation.
A photon has no rest mass, but it has momentum. (Light reflecting from a mirror pushes the mirror with a force that can be measured.) In the case of a photon, because its m0 = 0, then:
E2 = 0 + (pc)2
E = pc
p = E/c
The energy of a photon can be computed from its frequency ν or wavelength λ. These are related to each other by Planck's relation, E = hν = hc/λ, where h is the Planck constant (6.626×10−34 joule-seconds). Knowing either frequency or wavelength, you can compute the photon's momentum.
In the case of motionless particles with mass, since p = 0, then:
E02 = (m0c2)2 + 0
which is just
E0 = m0c2
Therefore, the quantity "m0" used in Einstein's equation is sometimes called the "rest mass." (The "0" reminds us that we are talking about the energy and mass when the speed is 0.) This famous "mass-energy relation" formula (usually written without the "0"s) suggests that mass has a large amount of energy, so maybe we could convert some mass to a more useful form of energy. The nuclear power industry is based on that idea.
Einstein said that it was not a good idea to use the classical formula relating momentum to velocity, p = mv, but that if someone wanted to do that, he would have to use a particle mass m that changes with speed:
mv2 = m02 / (1 – v2/c2)
In this case, we can say that E = mc2 is also true for moving particles.
 The General Theory of Relativity 
The General Theory of Relativity was published in 1915, ten years after the special theory of relativity was created. Einstein's general theory of relativity uses the idea of spacetime. Spacetime is the fact that we have a four-dimensional universe, having three spatial (space) dimensions and one temporal (time) dimension. Any physical event happens at some place inside these three space dimensions, and at some moment in time. According to the general theory of relativity, any mass causes spacetime to curve, and any other mass follows these curves. Bigger mass causes more curving. This was a new way to explain gravitation (gravity).
General relativity explains gravitational lensing, which is light bending when it comes near a massive object. This explanation was proven correct during a solar eclipse, when the sun's bending of starlight from distant stars could be measured because of the darkness of the eclipse.
General relativity also set the stage for cosmology (theories of the structure of our universe at large distances and over long times). Einstein thought that the universe may curve a little bit in both space and time, so that the universe always had existed and always will exist, and so that if an object moved through the universe without bumping into anything, it would return to its starting place, from the other direction, after a very long time. He even changed his equations to include a "cosmological constant," in order to allow a mathematical model of an unchanging universe. The general theory of relativity also allows the universe to spread out (grow larger and less dense) forever, and most scientists think that astronomy has proved that this is what happens. When Einstein realized that good models of the universe were possible even without the cosmological constant, he called his use of the cosmological constant his "biggest blunder," and that constant is often left out of the theory. However, many scientists now believe that the cosmological constant is needed to fit in all that we now know about the universe.
A popular theory of cosmology is called the Big Bang. According to the Big Bang theory, the universe was formed 15 billion years ago, in what is called a "gravitational singularity". This singularity was small, dense, and very hot. According to this theory, all of the matter that we know today came out of this point.
Einstein himself did not have the idea of a "black hole", but later scientists used this name for an object in the universe that bends spacetime so much that not even light can escape it. They think that these ultra-dense objects are formed when giant stars, at least three times the size of our sun, die. This event can follow what is called a supernova. The formation of black holes may be a major source of gravitational waves, so the search for proof of gravitational waves has become an important scientific pursuit.
 Beliefs 
Many scientists only care about their work, but Einstein also spoke and wrote often about politics and world peace. He liked the ideas of socialism and of having only one government for the whole world. He also worked for Zionism, the effort to try to create the new country of Israel.
In his final days, Einstein faced a crucial decision. Doctors offered surgery to treat his condition, but he chose a different path. He believed in living life naturally, saying, “I want to go when I want to go. It is tasteless to prolong life artificially.” With these words, Einstein showed us the dignity in accepting life’s natural cycle. On January 3, 1954, Einstein sent the following reply to Gutkind: "The word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish. .... For me the Jewish religion like all other religions is an incarnation of the most childish superstitions." In 2018 his letter to Gutkind was sold for $2.9 million.
Even though Einstein thought of many ideas that helped scientists understand the world much better, he disagreed with some scientific theories that other scientists liked. The theory of quantum mechanics discusses things that can happen only with certain probabilities, which cannot be predicted with more precision no matter how much information we might have. This theoretical pursuit is different from statistical mechanics, in which Einstein did important work. Einstein did not like the part of quantum theory that denied anything more than the probability that something would be found to be true of something when it was actually measured; he thought that it should be possible to predict anything, if we had the correct theory and enough information. He once said, "I do not believe that God plays dice with the Universe."
Because Einstein helped science so much, his name is now used for several different things. A unit used in photochemistry was named for him. It is equal to Avogadro's number multiplied by the energy of one photon of light. The chemical element Einsteinium is named after the scientist as well. In slang, we sometimes call a very smart person an "Einstein."
 Criticism 
Most scientists think that Einstein's theories of special and general relativity work very well, and they use those ideas and formulas in their own work. Einstein disagreed that phenomena in quantum mechanics can happen out of pure chance. He believed that all natural phenomena have explanations that do not include pure chance. He spent much of his later life trying to find a "unified field theory" that would include his general relativity theory, Maxwell's theory of electromagnetism, and perhaps a better quantum theory. Most scientists do not think that he succeeded in that attempt.


Timeline of Christianity: March 2025March 2025
This timeline is to show the history of Christianity from the beginning to the present. Question marks on dates mean that dates are not exact. 
Western culture and Christian churches use the Gregorian calendar. The Gregorian calendar has been in use since 1582 when it replaced the less precise Julian Calendar. The Gregorian calendar began in Europe, in the reign of Pope Gregory XIII. The Gregorian calendar is now used almost everywhere in the world (except for calculating the holy days of other religions). 
The Gregorian calendar dates years from before or after the birth of Jesus. Years that are before the birth of Jesus have the initials BC (before Christ) and years that are after (traditionally) have the initials AD (anno Domini – "in the year of our Lord"). Nowadays these are often written BCE ("before the Common Era") and CE ("Common Era").
The "year one" is the first year in "anno Domini" (the Common Era). There is no year zero. When the Gregorian calendar was calculated, the scholars tried to work out exactly when the birth of Jesus happened. The exact date is not certain, but most agree that it was between 6 BC and 4 BC.
Era of Jesus 
This list tells only about the things that happened in the part of the world where Jesus was born. This region is now called Israel and Palestine. In the time of Jesus, it was under the rule of the Romans.
1 This year is sometimes celebrated as beginning near the time of Jesus' birth. People who study it now say that it was calculated wrongly and he was born in 4 BC.
6 Herod Archelaus was deposed (put off his throne) by Caesar Augustus. The Roman rulers brought together Samaria, Judea and Idumea as "Iudaea Province" with its capital at Caesarea. Quirinius became Governor of Syria. Quininus conducted a census and was opposed by a Jewish group called the Zealots (JA18, (Luke 2:1–3, Acts 5:37)
7–26 Brief period of peace, relatively free of revolt and bloodshed in Iudaea and Galilee (John P. Meier's A Marginal Jew, v. 1, ch. 11)
9 Pharisee leader Hillel the Elder dies, temporary rise of Shammai
14–37 Tiberius, Roman Emperor
18–36 Caiaphas, appointed High Priest of Herod's Temple by Prefect Valerius Gratus, deposed by Syrian Legate Lucius Vitellius
19 Jews, Jewish proselytes, astrologers, expelled from Rome (Suetonius, Lives of the Twelve Caesars, Tiberius 36, Loeb Classics)
26–36 Pontius Pilate, Prefect (governor) of Judaea, recalled to Rome by Syrian Legate Vitellius on complaints of excess violence (JA18.4.2)
28 or 29 John the Baptist began his ministry in the "15th year of Tiberius" (Luke 3:1–2), saying: "Repent, for the kingdom of heaven is near" ( Matt 3:1–2), a relative of Jesus (Luke 1:36 NRSV), a Nazirite ( Luke 1:15), baptized Jesus (Mark 1:4–11), later arrested and beheaded by Herod Antipas (Luke 3:19–20), it is possible that, according to Josephus' chronology, John was not killed until 36 (JA18.5.2)
Jesus began his ministry after his baptism by John and during the rule of Pilate, preaching: "Repent, for the kingdom of heaven is near" ( Matt 4:12–17). While the historicity of the gospel accounts is questioned to some extent by most critical scholars and non-Christians, the traditional view states the following chronology for his ministry: Temptation, Sermon on the Mount, Appointment of the Twelve, Miracles, Temple Money Changers, Last Supper, Arrest, Trial, Passion, Crucifixion on Good Friday (Mark 15:42, John 19:42), Nisan 14th ( John 19:14, Mark 14:2, Gospel of Peter) or Nisan 15th (Synoptic Gospels), (7 Apr 30, 3 Apr 33, 30 Mar 36, possible Fri-14-Nisan dates – Meier), entombment by Pharisees Joseph of Arimathea and Nicodemus of the Sanhedrin, Resurrection by God on Easter Sunday, appearances to Paul of Tarsus (1Cor 15:3–9), Simon Peter (Luke 24:34), Mary Magdalene (Mark 16:9, John 20:10–18), and others, Great Commission, Ascension, Second Coming Prophecy to fulfill the rest of Messianic prophecy such as the Resurrection of the dead, the Last Judgment, and establishment of the Kingdom of God and the Messianic Age. See also Chronology of Jesus.
Era of the Apostles
Acts of the Apostles Paul of Tarsus
Shortly after the Crucifixion of Jesus (Nisan 14 or 15), the Jerusalem church was founded as the first Christian church with about 120 Jews and Jewish proselytes (Acts 1:15), followed by Pentecost, the Ananias and Sapphira incident, Pharisee Gamaliel's defense of the Apostles (Acts 5:34–39), the stoning of Saint Stephen (see also Persecution of Christians) and the subsequent dispersal of the church (Acts 7:54–8:8) which led to the baptism of Simon Magus in Samaria (Acts 8:9–24), and also an Ethiopian eunuch (Acts 8:26–40). Paul's conversion to "Apostle to the Gentiles" is first recorded in ( Acts 9:13–16, cf. Gal 1:11–24). Peter baptized the Centurion Cornelius, who is traditionally considered the first Gentile convert to Christianity (Acts 10). The Antioch church was founded. It was there that the term Christian was first used (Acts 11:26). Saint James was executed by Agrippa I (ruled 39–44) during a Passover (Nisan 15) (Acts 12:1–3).
44 Death of Agrippa I (JA19.8.2, Acts 12:20–23)
44–46? Theudas beheaded by Procurator Cuspius Fadus for saying he would part the Jordan river (like Moses and the Red Sea) (JA20.5.1, Acts 5:36–37 places it before the Census of Quirinius)
45–49? Paul's first mission ( Acts 13:1–14:28), with Barnabas, to Cyprus, Pisidian Antioch, Iconium, Lystra and Derbe (there they were called "gods ... in human form"), then return to Syrian Antioch
47? The Church of the East is created by Saint Thomas
48–100 Herod Agrippa II appointed King of the Jews by Claudius, seventh and last of the Herodians
49 "Since the Jews constantly made disturbances at the instigation of Chrestus, he, Claudius, expelled them from Rome." (Suetonius, Lives of the Twelve Caesars, Claudius XXV.4, Loeb Classics) (referenced in Acts 18:2)
50 Passover riot in Jerusalem, 20–30,000 killed (JA20.5.3, JW2.12.1)
50? Council of Jerusalem and the "Apostolic Decree", Acts 15:1–35, same as Galatians 2:1–10?, which is followed by the "Incident at Antioch" at which Paul publicly accused Peter of "Judaizing" ( Galatians 2:11–21)
50–53? Paul's second mission ( Acts 15:36–18:22), split with Barnabas, to Phrygia, Galatia, Macedonia, Philippi, Thessalonica, Berea, Athens, Corinth, "he had his hair cut off at Cenchrea because of a vow he had taken", then return to Antioch; 1 Thessalonians, Galatians written?
52? Saint Thomas Christians of India
53–57? Paul's third mission ( Acts 18:23–22:30), to Galatia, Phrygia, Corinth, Ephesus, Macedonia, Greece, and Jerusalem where James the Just challenged him about a rumor of teaching antinomianism (Acts 21:21). He addressed a crowd in their language (most likely Aramaic), Romans, 1 Corinthians, 2 Corinthians, Philippians written?
55? "Egyptian Prophet" (allusion to Moses) and 30,000 unarmed Jews doing the Exodus reenactment massacred by Procurator Antonius Felix (JW2.13.5, JA20.8.6, Acts 21:38)
58? Paul arrested, accused of being a revolutionary, "ringleader of the sect of the Nazarenes", teaching resurrection of the dead, imprisoned in Caesarea (Acts 23–26)
59? Paul shipwrecked on Malta. There he was called a god. (Acts 28:6)
60? Paul in Rome: greeted by many "brothers" (NRSV: "believers"), three days later called together the Jewish leaders, who had not received any word from Judea about him, but were curious about "this sect", which everywhere is spoken against; he tried to convince them from the "Law and Prophets", with partial success, said the Gentiles would listen and spent two years proclaiming the Kingdom of God and teaching the "Lord Jesus Christ" (Acts 28:15–31); Epistle to Philemon written?
62 James the Just stoned to death for law transgression by High Priest Ananus ben Artanus. Popular opinion against act results in Ananus being deposed by new procurator Clodius Albinus. (JA20.9.1)
63–107? Simeon, second Bishop of Jerusalem, crucified under Trajan
63? Glastonbury Abbey founded according to tradition, but date disputed
64–68 after July 18 Great Fire of Rome, Nero blamed and persecuted the Christians, earliest mention of Christians, by that name, in Rome, see also Tacitus on Jesus, Paul beheaded? ( Col 1:24, Eph 3:13, 2 Tim 4:6–8 NRSV, 1Clem 5:5–7), Peter crucified upside down? ( Jn 21:18, 1 Pet 5:13, Tertullian's Prescription Against Heretics chapter XXXVI, Eusebius' Church History Book III chapter I), "...a vast multitude, were convicted, not so much of the crime of incendiarism as of hatred of the human race. And in their deaths they were made the subjects of sport; for they were wrapped in the hides of wild beasts and torn to pieces by dogs, or nailed to crosses, or set on fire, and when day declined, were burned to serve for nocturnal lights." (Annals (Tacitus) XV.44)
Early Christianity
Early Christianity
65? Q document, a hypothetical Greek text thought by many critical scholars to have been used in writing of Matthew and Luke
66–73 Great Jewish Revolt: destruction of Herod's Temple, Qumran community destroyed, site of Dead Sea Scrolls found in 1947
68–107? Ignatius, third Bishop of Antioch, fed to the lions in the Roman Colosseum, advocated the Bishop (Eph 6:1, Mag 2:1,6:1,7:1,13:2, Tr 3:1, Smy 8:1,9:1), rejected Jewish Sabbath on Saturday in favor of The Lord's Day (Sunday). (Mag 9.1), rejected Judaizing (Mag 10.3), first use of term Christianity (Mag 10).
70(±10)? Gospel of Mark, written in Rome, by Peter's interpreter (1 Peter 5:13), original ending apparently lost, endings added c. 400, see Mark 16
70? Signs Gospel written, hypothetical Greek text used in Gospel of John to prove Jesus is the Messiah
70–100? additional Pauline Epistles
70–200? Didache; Other Gospels: Unknown Berlin Gospel, Gospel of Peter, Gospel of Thomas, Oxyrhynchus Gospels, Egerton Gospel, Fayyum Fragment, Dialogue of the Saviour; Jewish Christian Gospels: Gospel of the Ebionites, Gospel of the Hebrews, Gospel of the Nazarenes
80(±20)? Gospel of Matthew, based on Mark and Q, most popular in Early Christianity
80(±20)? Gospel of Luke, based on Mark and Q, also Acts of the Apostles by same author
88–101? Clement, fourth Bishop of Rome, wrote Letter of the Romans to the Corinthians (Apostolic Fathers)
90? Council of Jamnia of Judaism (disputed)
90(±10)? 1 Peter
94 Testimonium Flavianum, disputed section of Jewish Antiquities by Josephus in Aramaic, translated to Koine Greek
95(±30)? Gospel of John and Epistles of John
95(±10)? Book of Revelation written, by John (son of Zebedee) and/or a disciple of his
100(±30)? Epistle of Barnabas (Apostolic Fathers)
100(±25)? Epistle of James
100(±10)? Epistle of Jude written, probably by doubting relative of Jesus (Mark 6:3), rejected by some early Christians due to its reference to apocryphal Book of Enoch (v14). Epistle to the Hebrews written.
100–150? Apocryphon of James, Gospel of Mary Magdalene, Gospel of James, Infancy Gospel of Thomas, Secret Gospel of Mark (Complete Gospels, published by Jesus Seminar)
110–130? Papias, bishop of Hierapolis, wrote: "Expositions of the Sayings of the Lord", lost, widely quoted (Apostolic Fathers)
110–160? Polycarp, bishop of Smyrna, Letter to the Philippians, (Apostolic Fathers)
125(±5)? 2 Peter written, not accepted into canon until early 400s, drew upon Epistle of Jude, "catholic" epistle, Pastoral Epistles written
125? Rylands Library Papyrus P52, oldest extant NT fragment, p. 1935, parts of Jn18:31–33,37–38
130–250? "Christian Apologists" writings against Roman religion: Justin Martyr, Athenagoras, Apology of Aristides, Theophilus of Antioch, Tatian, Quadratus, Melito of Sardis, Apollinaris Claudius, Felix Marcus Minucius, Arnobius, Epistle to Diognetus
132–135 Bar Kokhba's revolt: final Jewish revolt, Judea and Jerusalem erased from maps, region renamed Syria Palæstina (the term Palestine was originally coined by Herodotus), Jerusalem renamed Aelia Capitolina
142–144? Marcion of Sinope, bishop according to Catholic Encyclopedia, went to Rome, possibly to buy the bishopric of Rome, upon rejection formed his own church in Rome, later called Marcionism, rejected Old Testament, decreed canon of one Gospel, one Apostolicon (10 Letters of Paul) and one Antithesis which contrasted the Old Testament with the New Testament, cited Western text-type, see also Expounding of the Law#Antithesis of the Law
150? "Western Revisor" adds/subtracts from original Acts to produce Western version which is 10% larger and found in Papyrus P29,38,48 and Codex Bezae (D)
150? Valentinius, most famous Christian Gnostic, according to Tertullian narrowly lost election for Bishop of Rome
150(±10)? Shepherd of Hermas, written in Rome (Apostolic Fathers)
155? Montanus, claimed to be the Paraclete ("Counselor") of John 14:16
160? Martyrdom of Polycarp (Apostolic Fathers)
170? Dionysius , bishop of Corinth, claimed Christians were changing and faking his own letters just as [he knew] they had changed the Gospels (Eusebius' EH 4 c.23 v.12;Ante-Nicene Fathers, v.8)
170? Tatian produces "Diatessaron" (Harmony) by blending four "Western" text-type Gospels into one
170? Symmachus the Ebionite, new Greek translation of Hebrew Bible
180? Hegesippus
180–202? Irenaeus, Bishop of Lyon, combated heresies, cited "Western" Gospel text-type (Ante-Nicene Fathers)
185–350? Muratorian fragment, 1st extant canon for New Testament after Marcion?, written in Rome by Hippolytus?, excludes Hebrews, James, 1–2 Peter, 3 John; includes Wisdom of Solomon, Apocalypse of Peter
186? Saint Apollonius, used the term catholic in reference to 1 John
188–231 Saint Demetrius, bishop of Alexandria, condemned Origen
189–198 Pope Victor I, 1st Latin Pope, excommunicated Eastern churches that continued to observe Easter on Nisan 14 Quartodeciman
196? Polycrates, bishop of Ephesus (Ante-Nicene Fathers)
199–217? Caius , presbyter of Rome, wrote "Dialogue against Proclus" in Ante-Nicene Fathers, rejected Revelation, said to be by Gnostic Cerinthus
200? Papyrus 46: 2nd Chester Beatty, Alexandrian text-type; Papyrus 66: 2nd Bodmer, John, 1956, "Alexandrian/Western" text-types; Papyrus 75: Bodmer 14–15, Luke and John, earliest extant Luke, ~Vaticanus; 200? Papyrus 32: J. Rylands Library: Titus 1:11–15;2:3–8; Papyrus 64 (+67): Mt3:9,15; 5:20–22,25–28; 26:7–8,10,14–15,22–23,31–33
200? Sextus Julius Africanus
200? Antipope Natalius , rival bishop of Rome, according to Eusebius's EH5.28.8–12, quoting the Little Labyrinth of Hippolytus, after being "scourged all night by the holy angels", covered in ash, dressed in sackcloth, and "after some difficulty", tearfully submitted to Pope Zephyrinus
217–236 Antipope Hippolytus, Logos sect?
218–258 Cyprian, Bishop of Carthage, cited "Western" NT text-type, claimed Christians were freely forging his letters to discredit him (Ante-Nicene Fathers)
220? Clement of Alexandria, cited "Alexandrian" NT text-type and Secret Gospel of Mark and Gospel of the Egyptians; wrote: "Exhortations to the Greeks"; "Rich Man's Salutation"; "To the Newly Baptized"; (Ante-Nicene Fathers)
220?–340? Codex Tchacos, manuscript containing a copy of the Gospel of Judas, has been written.
223? Tertullian, sometimes called "father of the Latin Church" because he coined trinitas, tres Personae, una Substantia, Vetus Testamentum, Novum Testamentum, convert to Montanism, cited "Western" Gospel text-type (Ante-Nicene Fathers)
225? Papyrus 45: 1st Chester Beatty, Gospels (Caesarean text-type), Acts (Alexandrian text-type)
235–238 Maximinus Thrax, emperor of Rome, ends Christian schism in Rome by deporting Pope Pontian and Antipope Hippolytus to Sardinia where they soon die
248–264 Dionysius, Patriarch of Alexandria see also List of Patriarchs of Alexandria
250? Apostolic Constitutions, Liturgy of St James, Old Roman Symbol, Clementine literature
250? Letters of Methodius, Pistis Sophia, Porphyry Tyrius, Commodianus (Ante-Nicene Fathers)
250? Papyrus 72: Bodmer 5–11+, pub. 1959, "Alexandrian" text-type: Nativity of Mary; 3Cor; Odes of Solomon 11; Jude 1–25; Melito's Homily on Passover; Hymn fragment; Apology of Phileas; Ps33,34; 1Pt1:1–5:14; 2Pt1:1–3:18
250? Origen, Jesus and God one substance, adopted at First Council of Nicaea in 325, compiled Hexapla; cites Alexandrian, Caesarean text-type; Eusebius claimed Origen castrated himself for Christ due to Mt19:12 (EH6.8.1–3)
251–424? Synods of Carthage
251–258 Antipope Novatian, decreed no forgiveness for sins after baptism
254–257 Pope Stephen I; major schism over rebaptizing heretics and apostates
258 "Valerian's Massacre": Roman emperor issued edict to execute immediately all Christian bishops, presbyters, and deacons, including Pope Sixtus II, Antipope Novatian, Cyprian of Carthage (CE: Valerian, Schaff's History Vol 2 Chap 2 § 22)
264–269 Synods of Antioch, condemned Paul of Samosata, Bishop of Antioch, founder of adoptionism (Jesus was human until Holy Spirit descended at his baptism), also condemned term homoousios adopted at Nicaea
265 Gregory Thaumaturgus (Ante-Nicene Fathers)
270? Anthony begins monastic movement
275? Papyrus 47: 3rd Chester Beatty, ~Sinaiticus, Rev9:10–11:3,5–16:15,17–17:2
276 Mani (prophet), crucified, founder of the dualistic Manichaean sect in Persia
282–300? Theonas, bishop of Alexandria (Ante-Nicene Fathers)
290–345? St Pachomius, founder of Christian monasticism
296–304 Pope Marcellinus, offered pagan sacrifices for Diocletian
301 Armenia, first to adopt Christianity as state religion
303–312 Diocletian's Massacre of Christians
303 Saint George, patron saint of England, and other states
304? Victorinus, bishop of Pettau
306 Synod of Elvira, prohibited relations between Christians and Jews
310 Maxentius deports Pope Eusebius and Heraclius to Sicily (relapse controversy)
312 Lucian of Antioch, founded School of Antioch, martyred
312 Vision of Constantine: while gazing into the sun he saw a cross with the words by this sign conquer. See also Labarum. He was later called the 13th Apostle and Equal-to-apostles.
313 Edict of Milan, Constantine and Licinius end persecution, establish toleration of Christianity
313? Lateran Palace given to Pope Miltiades for residence by Constantine
314 Council of Arles , called by Constantine against Donatist schism
314–340? Eusebius, bishop of Caesarea, church historian, cited Caesarean text-type, wrote Ecclesiastical History in 325 
317? Lactantius
321 Constantine decreed Sunday as state "day of rest" (CJ3.12.2), see also Sol Invictus
Era of the Seven Ecumenical Councils
Constantine called the First Council of Nicaea in 325 to unify Christology, also called the first great Christian council by Jerome, the first ecumenical, decreed the Original Nicene Creed, but rejected by Nontrinitarianism such as Arius, Theonas, Secundus, Eusebius of Nicomedia, and Theognis who were excommunicated, also addressed Easter controversy and passed 20 Canon laws.
325 The Kingdom of Aksum (Modern Ethiopia) declares Christianity as the official state religion becoming the second country to do so
325 Church of the Nativity in Bethlehem, ordered by Constantine
326, November 18 Pope Sylvester consecrates the Basilica of St. Peter built by Constantine the Great over the tomb of the Apostle.
328–373 Athanasius, bishop of Alexandria, first cite of modern 27 book New Testament canon
330 Old Church of the Holy Apostles, dedicated by Constantine
330, May 11 Constantinople solemnly inaugurated. Constantine moves the capital of the Roman Empire to Byzantium, renaming it New Rome.
335 Council in Jerusalem, reversed Nicaea's condemnation of Arius, consecrated Jerusalem Church of the Holy Sepulchre
337 Mirian III of Georgia, second to adopt Christianity as state religion
May 22, 337: Constantine the Great dies. Baptized shortly before his death.
343? Council of Sardica
350? Julius Firmicus Maternus
350? Codex Sinaiticus(א), Codex Vaticanus(B): earliest Christian Bibles, Alexandrian text-type
350? Ulfilas, Arian, apostle to the Goths, translated Greek NT to Gothic
350? Comma Johanneum 1Jn5:7b–8a(KJV)
350? Aëtius, Arian, "Syntagmation": "God is agennetos (unbegotten)", (Anomoean)
350? School of Nisibis founded
351 2nd Council of Sirmium, Anomoean, condemned Council of Nicaea
353–367 Hilary, bishop of Poitiers
355–365 Antipope Felix II, Arian, supported by Constantius II, consecrated by Acacius of Caesarea
359 Council of Rimini, Dated Creed (Acacians)
 360: Julian the Apostate becomes the last non-Christian Roman Emperor.
363–364 Council of Laodicea, canon 29 decreed anathema for Christians who rest on the Sabbath, disputed canon 60 named 26 NT books (excluded Revelation)
366–367 Antipope Ursicinus, rival to Pope Damasus I
367–403 Epiphanius, bishop of Salamis, wrote Panarion against heresies
370–379 Basil the Great, Bishop of Caesarea
370? Doctrine of Addai at Edessa proclaims 17 book NT canon using Diatessaron (instead of the 4 Gospels) + Acts + 15 Pauline Epistles (inc. 3 Corinthians) Syriac Orthodox Church
372–394 Gregory, Bishop of Nyssa
373 Ephrem the Syrian, cited Western Acts
374–397 Ambrose, bishop and governor of Milan
375–395 Ausonius, Christian governor of Gaul
379–381 Gregory Nazianzus, Bishop of Constantinople
380, February 27 Emperor Theodosius issues the edict De Fide Catolica declaring Catholic Christianity as the official state religion of the Roman Empire
November 24, 380: Emperor Theodosius I is baptised.
381 First Council of Constantinople, second ecumenical, Jesus had true human soul, Nicene Creed of 381
382 Council of Rome under Pope Damasus I sets the Biblical Canon, listing the inspired books of the Old Testament and the New Testament (disputed)
383? Frumentius, Apostle of Ethiopia
385 Priscillian, first heretic to be executed?
390? Apollinaris, bishop of Laodicea, believed Jesus had human body but divine spirit
391: The Theodosian decrees outlaw most pagan rituals still practiced in Rome.
396–430 Augustine, bishop of Hippo, considered the founder of formalized Christian theology (Nicene and Post-Nicene Fathers)
397? Saint Ninian evangelizes Picts in Scotland
398–404 John Chrysostom Patriarch of Constantinople, (Nicene and Post-Nicene Fathers)
400: Jerome's Vulgate Latin edition and translation of the Bible is published.
400? Ethiopic Bible: in Ge'ez, 81 books, standard Ethiopian Orthodox Bible
400? Peshitta Bible in Syriac (Aramaic), Syr(p), OT + 22 NT, excludes: 2Pt, 2–3Jn, Jude, Rev; standard Syriac Orthodox Church Bible
406 Armenian Bible, translated by Saint Mesrob, standard Armenian Orthodox Bible
24 August 410: Sack of Rome by Alaric and the Visigoths.
412–444 Cyril, bishop of Alexandria, expelled Jews, killed Hypatia with oyster shells, coined Hypostatic union
418–419 Antipope Eulalius rival to Pope Boniface I
420 St. Jerome, Vulgate translations, Latin scholar, cited expanded ending in Mark after Mark 16:8, Pericope of the Adultress addition to John (John 7:53–8:11) (Nicene and Post-Nicene Fathers)
423–457 Theodoret, bishop of Cyrrhus, noted Tatian's Diatesseron in heavy use, wrote a Church History
431 Council of Ephesus, third ecumenical, repudiated Nestorianism, decreed Mary the Mother of God, forbid any changes to Nicene Creed of 381, rejected by Assyrian Church of the East
432 St Patrick begins mission in Ireland. Almost the entire nation is Christian by the time of his death in a conversion that is both incredibly successful and largely bloodless.
440–461 Pope Leo the Great, sometimes considered the first pope, stopped Attila the Hun at Rome, issued Tome in support of Hypostatic Union, approved Council of Chalcedon but rejected canons in 453
447 Council of Toledo added Filioque clause to Nicene Creed of 381
449 Second Council of Ephesus, Monophysite: Jesus was divine but not human
450? Codex Alexandrinus(A): Alexandrian text-type; Codex Bezae(D): Greek/Latin Gospels + Acts; Codex Washingtonianus(W): Greek Gospels; both of Western text-type
450? std. Aramaic Targums, Old Testament in Aramaic
450? Socrates Scholasticus Church History of 305–438; Sozomen Church History of 323–425
451 Council of Chalcedon, fourth ecumenical, declared Jesus is a Hypostatic Union: both human and divine in one, Chalcedonian Creed, rejected by Oriental Orthodoxy
455: Sack of Rome by the Vandals. The spoils of the Temple of Jerusalem previously taken by Titus are allegedly among the treasures taken to Carthage.
456? Eutyches of Constantinople, Monophysite
452: Pope Leo I (the Great) dissuades Attila the Hun, the Scourge of God, from sacking Rome.
465? Prosper of Aquitaine
476, September 4 Emperor Romulus Augustus is deposed in Rome, marked by many as the fall of the Western Roman Empire
484–519 Acacian Schism, over Henoticon divides Eastern (Greek) and Western (Latin) churches
491 Armenian Orthodox split from East (Greek) and West (Latin) churches
495 May13 Vicar of Christ decreed a title of Bishop of Rome by Pope Gelasius I
496 Clovis I, King of the Franks, baptized
498–499,501–506 Antipope Laurentius, rival of Pope Symmachus, Laurentian schism
500? Incense introduced in Christian church service, first plans of Vatican
524 Boethius, Roman Christian philosopher, wrote: Theological Tractates, Consolation of Philosophy;
525 Dionysius Exiguus defines Christian calendar (AD)
527 Fabius Planciades Fulgentius
530 Antipope Dioscorus, possibly a legitimate Pope
530 Rule of St Benedict, St. Benedict founds the Benedictines
535–536 Unusual climate changes recorded
537–555 Pope Vigilius, involved in death of Pope Silverius, conspired with Justinian and Theodora, on April 11, 548, issued Judicatum supporting Justinian's anti-Hypostatic Union, excommunicated by bishops of Carthage in 550
541–542 Plague of Justinian
543 Justinian condemns Origen, disastrous earthquakes hit the world
544 Justinian condemns the Three Chapters of Theodore of Mopsuestia (d.428) and other writings of Hypostatic Union Christology of Council of Chalcedon
550 St. David converts Wales, crucifix introduced
553 Second Council of Constantinople, fifth ecumenical, called by Justinian
556–561 Pope Pelagius I, selected by Justinian, endorsed Judicatum
563 Columba goes to Scotland to evangelize Picts, establishes monastery at Iona
567 Cassiodorus
589 Third Council of Toledo, Reccared and the Visigoths convert from Arianism to Catholicism
590–604 Pope Gregory the Great, whom many consider the greatest pope ever, reforms church structure and administration and establishes Gregorian chant, seven deadly sins ...
591–628 Theodelinda, Queen of the Lombards, began gradual conversion from Arianism to Catholicism
596 St. Augustine of Canterbury sent by Pope Gregory to evangelise the Jutes
600? Evagrius Scholasticus, Church History of AD 431–594 https://web.archive.org/web/20090913125757/http://www.ccel.org/p/pearse/morefathers/evagrius_0_intro.htm 2009-09-13 
604 St Paul's Cathedral in London
607 Pope Boniface III, first Bishop of Rome to be called "Pope" and "Universal Bishop" by decree of Emperor Phocas
609 Pantheon, Rome renamed Church of Santa Maria Rotonda
612? Bobbio monastery in northern Italy
613 Abbey of St. Gall in Switzerland
614 Khosrau II of Persia conquered Damascus, Jerusalem, took Holy Cross of Christ
624 Battle of Badr, considered beginning of Islamic Empire
625 Paulinus of York comes to convert Northumbria
628 Babai the Great, pillar of Assyrian Church of the East, died
628–629 Battle of Mut'ah, Heraclius recovered Cross of Christ and Jerusalem from Islam till 638
632 Eorpwald of East Anglia baptized under influence of Edwin of Northumbria
634–644 Umar, second Sunni Islam Caliph, capital at Damascus, conquered Syria in 635, defeated Heraclius at Battle of Yarmuk in 636, conquered Egypt and Armenia in 639, Persia in 642
635 Cynegils of Wessex baptized by Bishop Birinus
640 Library of Alexandria, "The Center of Western Culture," with 300,000 ancient papyrus scrolls, is completely destroyed.
664 Synod of Whitby unites Celtic Christianity of British Isles with Roman Catholicism
680–681 Third Council of Constantinople, 6th ecumenical, against Monothelites, condemned Pope Honorius I, Patriarch Sergius I of Constantinople, Heraclius' Ecthesis
681–686 Wilfrid converts Sussex
687–691 Dome of the Rock built
690? Old English Bible translations
692 Orthodox Quinisext Council, convoked by Justinian II, approved Canons of the Apostles of Apostolic Constitutions, Clerical celibacy, rejected by Pope Constantine
698 Fall of Carthage
711–718 Umayyad conquest of Hispania
717–718 Second Arab siege of Constantinople
718–1492 Reconquista, Iberian Peninsula retaken by Christendom
718 Saint Boniface, an Englishman, given commission by Pope Gregory II to evangelize the Germans
720? Disentis Abbey of Switzerland
730–787 First Iconoclasm, Byzantine Emperor Leo III bans Christian icons, Pope Gregory II excommunicates him
731 English Church History written by Bede
750? Tower added to St Peter's Basilica at the front of the atrium
752? Donation of Constantine, granted Western Roman Empire to the Pope, later proved a forgery
756 Donation of Pepin recognizes Papal States
781 Nestorian Stele, Daqin Pagoda, Jesus Sutras, Christianity in China
787 Second Council of Nicaea, seventh ecumenical, ends first Iconoclasm
793 Sacking of the monastery of Lindisfarne marks the beginning of Viking raids on Christendom.
Middle Ages
Middle Ages
800 King Charlemagne of the Franks is crowned first Holy Roman Emperor of the West by Pope Leo III.
849–865 Ansgar, Archbishop of Bremen, "Apostle of the North", began evangelisation of North Germany, Denmark, Sweden
855 Antipope Anastasius, Louis II, Holy Roman Emperor appointed him over Pope Benedict III but popular pressure caused withdrawal
863 Saint Cyril and Saint Methodius sent by the Patriarch of Constantinople to evangelise the Slavic peoples. They translate the Bible into Slavonic.
869–870 Catholic Fourth Council of Constantinople, condemned Patriarch Photius, rejected by Orthodox
879–880 Orthodox Fourth Council of Constantinople, restored Photius, condemned Pope Nicholas I and Filioque, rejected by Catholics
897, January Cadaver Synod, Pope Stephen VI conducts trial against dead Pope Formosus. Public uprising against Stephen led to his imprisonment and strangulation.
909 Abbey of Cluny, Benedictine monastery in France
948? Einsiedeln Abbey of Switzerland
966 Mieszko I duke of Poland baptised. Poland becomes a Christian country.
984 Antipope Boniface VII, murdered Pope John XIV, alleged to have murdered Pope Benedict VI in 974
988 Baptism of Kievan Rus'
997–998 Antipope John XVI, deposed by Pope Gregory V and his cousin Holy Roman Emperor Otto III
999 Much speculation and fear regarding the approach of the millennium
1012 Antipope Gregory VI, removed by Henry II, Holy Roman Emperor
1030 Battle of Stiklestad, considered victory of Christianity over Norwegian paganism
1045 Sigfrid of Sweden, Benedictine evangelist
1046 Council of Sutri, Pope Silvester III exiled, Pope Gregory VI admitted to buying the papacy and resigned, Pope Benedict IX resigned, council appointed Pope Clement II
1054 East-West Schism split between Eastern (Orthodox Christianity) and Western (Roman Catholic) churches formalized
1058–1059 Antipope Benedict X, defeated in war with Pope Nicholas II and Normans
1061–1064 Antipope Honorius II rival of Pope Alexander II
1065 Westminster Abbey consecrated
1073–1085 Pope Gregory VII, Investiture Controversy with Henry IV, Holy Roman Emperor, proponent of clerical celibacy, opponent of simony, concubinage, Antipope Clement III
1079 Stanislaus of Szczepanów, patron saint of Poland
1082 Engelberg Abbey of Switzerland
1093–1109 Anselm, Archbishop of Canterbury, wrote Cur Deus Homo (Why God Became Man), a landmark exploration of the Atonement
1095–1291 Ten Crusades, first called by Pope Urban II at Council of Clermont against Islamic empire to reconquer the Holy Land for Christendom
1098 Foundation of the reforming monastery of Citeaux. Leads to the growth of the Cistercian order.
1101 Antipope Theodoric and Antipope Adalbert deposed by Pope Paschal II
1118 Knights Templar founded, to defend Holy Land
1123 Catholic First Lateran Council
1128 Holyrood Abbey in Scotland
1130 Peter of Bruys, burned at the stake
1131 Tintern Abbey in Wales
1131–1138 Antipope Anacletus II
1139 Catholic Second Lateran Council
1140? Decretum Gratiani, Catholic Canon law
1142 Peter Abélard, Letters of Abelard and Heloise
1144 The Saint Denis Basilica of Abbot Suger is the first major building in the style of Gothic architecture.
1154–1159 Pope Adrian IV, first (and to date only) English pope
1155 Theotokos of Vladimir arrives to Bogolyubovo
1155 Carmelites founded
1163 Notre Dame de Paris, construction begun
1173 Waldensians founded
1179 Catholic Third Lateran Council
1191 Teutonic Knights founded
1204–1261 Latin Empire of Constantinople
1205 Saint Francis of Assisi becomes a hermit, founding the Franciscan order of friars, renounces wealth and begins his ministry; the Rosary is reportedly given to St. Dominic (who founded Dominican Order) by an apparition of Mary
1215 Catholic Fourth Lateran Council, decreed special dress for Jews and Muslims
1220–1263 St Alexander Nevsky, holy patron of Russia
1231 Charter of the University of Paris granted by Pope Gregory IX.
1245 Catholic First Council of Lyon
1252 May 15, Ad exstirpanda, Pope Innocent IV authorized use of torture in Inquisitions
1260 Date which a 1988 Vatican-sponsored scientific study places the origin of the Shroud of Turin
1274 Summa Theologiae, written by Thomas Aquinas, theologian and philosopher, landmark systematic theology which later became official Catholic doctrine
1274 Catholic Second Council of Lyon
Renaissance
Renaissance
1305–1378 Avignon Papacy, Popes live in Avignon, France
1311 Divine Comedy, by Dante Alighieri
1311–1312 Catholic Council of Vienne, disbanded Knights Templar
1314 Jacques de Molay, last Grandmaster of Knights Templar, burned at the stake
1326 Metropolitan Peter moves his see from Kiev to Moscow
1341–1351 Orthodox Fifth Council of Constantinople
1342 Marsilius of Padua
1345 Sergii Radonezhskii founds a hermitage in the woods, which would grow into the Troitse-Sergiyeva Lavra
1378–1418 Western Schism in Roman Catholicism
1380–1382 Wyclif's Bible, by John Wycliffe, eminent theologian at Oxford, NT in 1380, OT (with help of Nicholas of Hereford) in 1382, translations into Middle English, first complete translation to English, included deuterocanonical books, preached against abuses, expressed anti-catholic views of the sacraments (Penance and Eucharist), the use of relics, and Clerical celibacy
1408 Council of Oxford forbids translations of the Scriptures into the vernacular unless and until they are fully approved by Church authority
1409 Council of Pisa, declared Roman Pope Gregory XII and Avignon Pope Benedict XIII deposed, elected Pope Alexander V (called the Pisan Pope)
1414–1418 Catholic Council of Constance, asked Gregory XII, Benedict XIII, Pisan Pope John XXIII to resign their papal claims, then elected Pope Martin V; condemned John Wycliffe and Jan Hus who was burned at the stake
1423–1424 Council of Siena
1425 Catholic University of Leuven
1430? Andrei Rublev, the greatest of medieval icon-painters
1431 St. Joan of Arc, French national heroine, burned at the stake
1431–1445 Catholic Council of Basel-Ferrara-Florence
1439 Notre-Dame de Strasbourg, highest building in the world till 1874
1453 Fall of Constantinople, overrun by Ottoman Empire
1455 Gutenberg Bible, first printed Bible, by Johann Gutenberg
1473–1481 Sistine Chapel built
1478 Spanish Inquisition established by Pope Sixtus IV
1484 December 5, Summis desiderantes against witchcraft issued by Pope Innocent VIII
1498 Girolamo Savonarola, Dominican priest, Bonfire of the Vanities
1506 Pope Julius II orders the Old St. Peter's Basilica torn down and authorizes Donato Bramante to plan a new structure. Demolition completed in 1606. Vatican Swiss Guard founded.
1508–1512 Michelangelo frescoes the Sistine Chapel's vaulted ceiling
1512–1517 Catholic Fifth Council of the Lateran, condemned Conciliarism
Reformation
Reformation
1517 95 Theses of Martin Luther begins German Protestant Reformation
1521 Diet of Worms condemns Luther
1521 Ferdinand Magellan claims the Philippines for Spain. First mass and subsequent conversion to Catholicism, first in East Asia.
1522 Luther's NT2024-08-09 User:Cewbot/log/20201008/configuration Martin Luther#Luther's German Bible , German NT translation
1525 Anabaptist movement begins
1526 Tyndale's NT, English NT translation from 1516 Greek text of Erasmus, first printed edition, used as a vehicle by Tyndale for bitter attacks on Catholicism, reflects influence of Luther's NT in rejecting priest for elder, church for congregation, banned in 1546 by Henry VIII
1530 Augsburg Confession, Luther founds the Lutheran Church
1531 Huldrych Zwingli, Protestant Reformation in Switzerland, independent of Luther
1531 Our Lady of Guadalupe in Mexico
1534 Henry VIII established independent Church of England, see also English Reformation
1534 Jesuit order founded by Ignatius of Loyola, helped reconvert large areas of Poland, Hungary, and S. Germany and sent missionaries to the New World, India, and China
1535–1537 Myles Coverdale's Bible, used Tyndale's NT along with Latin and German versions, included Apocrypha at the end of the OT (like Luther's Bible of 1534) as was done in later English versions. 1537 edition received royal license, but banned in 1546 by Henry VIII.
1535 Thomas More refused to accept King Henry VIII's claim to be the supreme head of the Church in England, and was executed.
1536 Desiderius Erasmus, Dutch scholar, Greek NT used in many 16th century translations
1536 Tyndale put to death, left his OT translation in manuscript. English ecclesiastical authorities ordered his Bible burned because it was thought to be part of Lutheran reform.
1536 Institutes of the Christian Religion written by John Calvin (Calvinism)
1536 John of Leiden, fanatic Dutch Anabaptist
1536 Jacob Hutter founder of Hutterites
1536 Helvetic Confessions of the Reformed Churches of Switzerland
1536–1540 Dissolution of the Monasteries in England, Wales and Ireland
1537 Christian III of Denmark decreed Lutheranism state religion of Norway and Denmark
1537–1551 Matthew Bible, by John Rogers, based on Tyndale and Coverdale, received royal license but not authorized for use in public worship, numerous editions, 1551 edition contained offensive notes (based on Tyndale)
1536–1541 Michelangelo paints the Last Judgement
1539–1569 Great Bible, by Thomas Cromwell, first English Bible to be authorized for public use in English churches, defective in many places, based on last Tyndale's NT of 1534–1535, corrected by a Latin version of the Hebrew OT, Latin Bible of Erasmus, and Complutensian Polyglot, last edition 1569, never denounced by England
1541 John Calvin returns to Geneva to establish a theocracy
1542 Roman Inquisition established by Pope Paul III
1543 Parliament of England bans Tyndale's translation as a "crafty, false and untrue translation"
1545–1563 Catholic Council of Trent, counter-reformation against Protestantism, clearly defined an official theology and biblical canon
1549 original Book of Common Prayer of the Church of England by Thomas Cranmer
1551 The Stoglav Church Council (One Hundred Chapters) Moscow, Russia
1552 Francis Xavier, Jesuit missionary, "Apostle of the Indies"
1553 Pontifical Gregorian University founded at Vatican City
1553 Michael Servetus founder of Unitarianism, burned at the stake in Geneva under Calvin
1553–1558 Queen Mary I of England, Bloody Mary, persecuted reformers: John Rogers, Hugh Latimer, Nicholas Ridley, Thomas Cranmer; of 238 burned at the stake
1559 Military Order of the Golden Spur founded by Pope Paul IV
1560 Geneva Bible, NT a revision of Matthew's version of Tyndale with use of Theodore Beza's NT (1556), OT a thorough revision of Great Bible, appointed to be read in Scotland (but not England), at least 140 editions, first Bible with chapter and verse numbers
1560 Scots Confession, Church of Scotland, Scottish Reformation
1560–1598 French Wars of Religion
1560–1812 Goa Inquisition, persecution of Hindus and Jews in India
1561 Menno Simons founder of Mennonites
1563 Thirty-Nine Articles of Church of England, also decreed biblical canon
1563 Heidelberg Catechism of Reformed churches
1566 Roman Catechism
1569 Metropolitan Philip of Moscow strangled by Malyuta Skuratov
1571 Dutch Reformed Church
1572 John Knox, founded Scotch Presbyterian Church, due to disagreement with Lutherans over sacraments and church government
1572–1606 Bishops' Bible, a revision of the Great Bible checked against the Hebrew text, first to be published in England by episcopal authority
1579 Discovery of the holiest Russian icon, Our Lady of Kazan
1580 Book of Concord of Lutheranism
1582 St Terese of Avila
1582 Gregorian calendar adopted at different times in different regions of the world
1587 Toyotomi Hideyoshi expelled Jesuits from Kyūshū
1587? Mission Nombre de Dios in St. Augustine, Florida, considered first mission to North America 
1589 Metropolitan Jove is elected the first Patriarch of Moscow
1590 Michelangelo's dome in St Peter's Basilica completed
1592 Clementine Vulgate of Pope Clement VIII, replaced Sistine Vulgate of 1590, standard Latin Catholic Bible till reforms of the Second Vatican Council
1596 Ukrainian Catholic Church forms when Ukrainian subjects of the king of Poland are reunited with Rome, largest Byzantine Catholic Church
17th century
1600 Giordano Bruno, Dominican priest, burned at the stake
1604 Fausto Paolo Sozzini Socinianism
1606 Carlo Maderno redesigns St Peter's Basilica into a Latin cross
1609 Baptist Church founded by John Smyth, due to objections to infant baptism and demands for church-state separation
1609–1610 Douay-Rheims Bible, first Catholic English translation. OT published in two volumes, based on an unofficial Louvain text corrected by Sistine Vulgate. NT is Rheims text of 1582.
1611–1800 King James Version (Authorised Version) is released, based primarily on Wycliffe's work and Bishop's Bible of 1572. Translators are accused of being "damnable corrupters of God's word". Original included Apocrypha.
1614 Fama Fraternitatis, Rosicrucian manifesto
1618–1648 Thirty Years' War
1620 Plymouth Colony founded
1621 Robert Bellarmine
1622–1642 Armand Jean du Plessis, Cardinal Richelieu
1630 City upon a Hill, sermon by John Winthrop
1636 Founding of what was later known as Harvard University as a training school for ministers – the first of thousands of institutions of Christian higher education founded in the USA
1636–1638 Cornelius Jansen, bishop of Ypres, founder of Jansenism
1637–1638 Shimabara Rebellion
1638 Anne Hutchinson banished as a heretic from Massachusetts
1641 John Cotton, advocate of theonomy, helps to establish the social constitution of the Massachusetts Bay Colony.
1643 Acta Sanctorum
1644 Long Parliament directed that only Hebrew canon be read in the Church of England (effectively removed the Apocrypha)
1646 Westminster Standards produced by the Assembly, one of the first and undoubtedly the most important and lasting religious document drafted after the reconvention of the Parliament, also decreed biblical canon
1648 George Fox founds the Quaker movement
1650 James Ussher, calculates date of creation as October 23, 4004 BC
1653–56 Raskol of the Russian Orthodox Church
1660–1685 King Charles II of England, restoration of monarchy, continuing through James II, reversed decision of Long Parliament of 1644, reinstating the Apocrypha, reversal not heeded by non-conformists
1672 Greek Orthodox Synod of Jerusalem, decreed biblical canon
1675 Philipp Jakob Spener publishes Pia Desideria, which becomes a manifesto for Pietism
1678 John Bunyan publishes Pilgrim's Progress
1682 Avvakum, leader of the Old Believers, burned at the stake in the Far North of Russia
1684 Roger Williams (theologian), advocate of separation of church and state, founder of Providence, Rhode Island
1685 Edict of Fontainebleau outlaws Protestantism in France
1685 Orthodoxy introduced to Beijing by Russian Orthodox Church
1692 Salem witch trials in Colonial America
1692–1721 Chinese Rites controversy
1693 Jacob Amman founder of Amish
18th century
1701 Old Catholic Church of the Netherlands splits with Roman Catholicism
1721 Peter the Great substituted Moscow Patriarchate with the Holy Synod
1728 The Vicar of Bray (song)
1730–1749 First Great Awakening in U.S.
1735 Welsh Methodist revival
1738 Methodist movement, led by John Wesley and his hymn-writing brother Charles, begins
1741 Sinners in the Hands of an Angry God, famous fire and brimstone sermon
1754 An Historical Account of Two Notable Corruptions of Scripture, by Isaac Newton, published
1767–1815 Suppression of the Jesuits
1768 New Smyrna, Florida, Greek Orthodox colony founded
1768 Reimarus dies without publishing his radical critic work distinguishing Historical Jesus versus Christ of Faith
1769 Mission San Diego de Alcala, first California mission
1772 Emanuel Swedenborg, founded Swedenborgianism
1774 Ann Lee leader of American Shakers
1774 Gotthold Ephraim Lessing starts publishing Reimarus works on historical Jesus as Anonymous Fragments, starting Liberal Theology Era (in Christology)
1776–1788 Gibbon's The History of the Decline and Fall of the Roman Empire, critical of Christianity
1776 Mission Delores, San Francisco
1779 Virginia Statute for Religious Freedom, "Jesus never coerced anyone to follow him, and the imposition of a religion by government officials is impious"
1780 Robert Raikes begins Sunday schools to reach poor and uneducated children in England
1784 American Methodists form Methodist Episcopal Church at so-called "Christmas Conference", led by bishops Thomas Coke and Francis Asbury
1789–1815 John Carroll, Roman Catholic Archdiocese of Baltimore, first Roman Catholic US bishop
1789–1801 Dechristianisation of France during the French Revolution
1791 First Amendment to the United States Constitution
1793 Herman of Alaska brings Orthodoxy to Alaska
1795 The Age of Reason written by Thomas Paine, advocated Deism
1796 Treaty with Tripoli (1796), article 11: "the Government of the United States of America is not, in any sense, founded on the Christian religion"
19th century
Industrial Revolution
1800 Friedrich Schleiermacher publishes his first book, beginning Liberal Christianity movement
1811 The Campbells begin Restoration Movement
1815 Peter the Aleut, orthodox Christian, tortured and martyred in Catholic San Francisco, California
1816 Bishop Richard Allen, a former slave, founds the African Methodist Episcopal Church, the first African-American denomination
1819 Thomas Jefferson produced the Jefferson Bible
1824 English translation of Wilhelm Gesenius' ...Handwörterbuch...: Hebrew-English Lexicon, Hendrickson Publishers
1828 Plymouth Brethren founded, Dispensationalism
1830 Charles Finney's revivals lead to Second Great Awakening in America
1830, April 6 Church of Jesus Christ of Latter Day Saints (Mormonism) founded by Joseph Smith, Jr. as a result of reported visitations and commandment by God the Father, Jesus Christ, and later the Angel Moroni. Book of Mormon also published in 1830.
1832 Church of Christ (Disciples) organized, made up of Presbyterians in distress over Protestant factionalism and decline of fervor
1833 John Keble's sermon "National Apostasy" initiates the Oxford Movement in England
1838–1839 Saxon Lutherans objecting to the Prussian Union emigrate from Germany to the United States; settle in Perry County, Missouri. Leads to formation of the LC-MS
1843 schism within the established Church of Scotland
1844, October 22 Great Disappointment, false prediction of Second Coming of Christ by Millerites
1845 Southern Baptist Convention formed in Augusta, Georgia
1848 Epistle to the Easterns and Encyclical of the Eastern Patriarchs response
1848 Perfectionist movement in western New York state
1854 Missionary Hudson Taylor arrives in China
1854 Immaculate Conception, defined as Catholic dogma
1855 Søren Kierkegaard, founder of Christian existentialism
1863 Seventh-day Adventist Church officially formed twenty 20 years after the Great Disappointment
1865 Methodist preacher William Booth founds the Salvation Army, vowing to bring the gospel into the streets to the most desperate and needy
1869–1870 Catholic First Vatican Council, asserted doctrine of Papal Infallibility, rejected by Christian Catholic Church of Switzerland
1870 Italy declared war on the Papal States. The Italian Army enters Rome. Papal States ceased to exist.
1871–1878 German Kulturkampf against Roman Catholicism
1879 Church of Christ, Scientist founded in Boston by Mary Baker Eddy
1881–1894 Revised Version, called for by Church of England, used Greek based on Septuagint (B) and (S), Hebrew Masoretic Text used in OT, follows Greek order of words, greater accuracy than AV, includes Apocrypha, scholarship never disputed
1884 Charles Taze Russell founded Bible Student movement known today as Jehovah's Witnesses
1885 Baltimore Catechism
1886 Moody Bible Institute
1894 The Kingdom of God is Within You, by Leo Tolstoy, start of Christian anarchism
1897 Christian flag, conceived in Brooklyn, New York
1899 Gideons International founded
20th century
1905 French law on the separation of Church and State
1906 Albert Schweitzer publishes The Quest of the Historical Jesus (English translation 1910)
1906 Biblia Hebraica
1906–1909 Azusa Street Revival in Los Angeles, California, begins modern Pentecostal movement
1907–1912 Nicholas of Japan, Archbishop of Japanese Orthodox Church
1909 Scofield Reference Bible
1909–1911 The Rosicrucian Fellowship, an international association of Christian mystics, founded at Mount Ecclesia
1910 Edinburgh Missionary Conference launches modern missions movement and modern ecumenical movement; five-point statement of the Presbyterian General Assembly, also used by Fundamentalists
1910–1915 The Fundamentals, a 12-volume collection of essays by 64 British and American scholars and preachers, a foundation of Fundamentalism
1913 Our Lady of Fatima appears to three young people, in Portugal. They were Jacinta Marto, Tiago Veloso and Lúcia (Sister Lucia).
1913 Catholic Encyclopedia
1914 Welsh Church Act 1914
1914 Iglesia ni Cristo incorporated in the Philippines
1915–1917 Armenian Genocide
1916 Father Divine founded International Peace Mission movement
1916 And did those feet in ancient time
1917 Restitution of the Moscow Patriarchy with Tikhon as patriarch
1917 True Jesus Church founded in Beijing
1918 Execution of Holy Martyrs of Russia, including the last tsar, Nicholas II, and his wife, Alexandra Feodorovna
1919 Karl Barth's Commentary on Romans is published, critiquing Liberal Christianity and beginning the neo-orthodox movement
1921 Oxford Group founded at Oxford
1923 Aimee Semple McPherson built Angelus Temple
1925 Scopes Trial, caused division among Fundamentalists
1925 United Church of Canada formed
1926 Father Charles Coughlin's first radio broadcast
1927 Pope Pius XI decrees Comma Johanneum open to dispute
1929 Lateran Treaty signed containing three agreements between kingdom of Italy and the papacy.
1930 Rastafari movement founded
1931 Majority of Bible Students adopt name Jehovah's Witnesses, see 1884 for more information.
1931 Christ the Redeemer (statue) in Rio de Janeiro, Brazil
1933 Catholic Worker Movement founded
1934 Herbert W. Armstrong founded Radio Church of God
1935 Dr. Frank C. Laubach, known as "The Apostle to the Illiterates", working in the Philippines, developed a literacy program that continues to teach millions of people to read.
1935 Rahlf's critical edition of the Koine Greek Septuagint
1935 Billy Sunday, early U.S. radio evangelist
1939 Southern and Northern US branches of the Methodist Episcopal Church, along with the Methodist Protestant Church reunite to form the Methodist Church. Slavery had divided the church in the 1800s.
1940 Monumento Nacional de Santa Cruz del Valle de los Caidos, world's largest cross, 152.4 meters high
1942 National Association of Evangelicals founded
1945 Roman Catholic sex abuse cases begin
1945 Dietrich Bonhoeffer is executed by the Nazis
1945 Ludwig Müller
1945 The Nag Hammadi library is discovered.
1946–1952 Revised Standard Version, revision of AV "based on consonantal Hebrew text" for OT and best available texts for NT, done in response to changes in English usage
1947 Uneasy Conscience of Modern Fundamentalism by Carl F. H. Henry, a landmark of Evangelicalism versus Fundamentalism in US
1947 Oral Roberts founded Evangelistic Association
1947 Dead Sea scrolls discovered
1948 World Council of Churches is founded
1948 Declaration of the Establishment of the State of Israel, see also Christian Zionism
1949 Evangelist Billy Graham preaches his first Los Angeles crusade
1950 New World Translation of the Christian Greek Scriptures released
1950 Assumption of Mary decreed by Pope Pius XII
1950 Missionaries of Charity founded by Mother Teresa
1951 The Last Temptation, a fictional account of the life of Jesus, written by Nikos Kazantzakis, wherein Christ's divinity is juxtaposed with his humanity, is published, and promptly banned in many countries.
1951 Campus Crusade for Christ founded at UCLA
1952 Novum Testamentum Graece, critical edition of Greek NT, basis of modern translations
1952 C. S. Lewis' Mere Christianity
1954 Unification Church founded
1954 U.S. Pledge of Allegiance modified by act of Congress from "one nation, indivisible" to "one nation under God, indivisible"
1956 In God We Trust designated U.S. national motto
1956 Anchor Bible Series
1957 United Church of Christ founded by ecumenical union of Congregationalists and Evangelical and Reformed, representing Calvinists and Lutherans
1957 English translation of Walter Bauer's Wörterbuch ...: A Greek-English Lexicon of the New Testament and Other Early Christian Literature, University of Chicago Press
1958 Sedevacantism
1961 New World Translation of the Holy Scriptures released
1962–1965 Catholic Second Vatican Council, announced by Pope John XXIII in 1959, produced 16 documents which became official Roman Catholic teaching after approval by the Pope, purpose to renew "ourselves and the flocks committed to us"
1963 Martin Luther King leads a civil rights march in Washington, D.C.
1963 campaign by Madalyn Murray O'Hair results in U.S. Supreme Court ruling prohibiting reading of Bible in public schools
1965 Reginald H. Fuller's The Foundations of New Testament Christology Rousas John Rushdoony founds Chalcedon Foundation
1966 Raymond E. Brown's Commentary on the Gospel of John
1968 United Methodist Church formed with union of Methodist Church and Evangelical United Brethren Church, becoming the largest Methodist/Wesleyan church in the world
1970s The Jesus movement takes hold in the U.S. One-way.org
1970 Mass of Paul VI replaces Tridentine Mass
1971 New American Standard Bible
1973 Trinity Broadcasting Network founded
1974 Jim Bakker founds PTL television ministry
1975 Bruce Metzger's Textual Commentary on the Greek New Testament
1977 Focus on the Family founded by James Dobson
1978 New International Version of the Bible is first published (revised in 1984), using a variety of Greek texts, Masoretic Hebrew texts, and current English style
1978–2005 Pope John Paul II, reaffirmed moral traditions (The Splendor of Truth)
1979 Moral Majority founded by Jerry Falwell
1979 Jesus, most watched movie of all time according to New York Times
1979–1982? New King James Version, complete revision of 1611 AV, updates archaisms while retaining style
1985 Jesus Seminar founded
1985 E. P. Sanders' Jesus and Judaism
1988 Christian Coalition
1988 The Last Temptation of Christ, directed by Martin Scorsese, is released by Universal Pictures, and promptly attacked as heretical by organized Christian and Catholic groups.
1989 New Revised Standard Version
1991 John P. Meier's series A Marginal Jew: Rethinking the Historical Jesus, v. 1
1992 Catechism of the Catholic Church
1994 "Evangelicals & Catholics Together" 
1994 Porvoo Communion
1994 Answers In Genesis founded by Ken Ham
1997, Mar 5–10 World Council of Churches: Towards a Common Date for Easter https://web.archive.org/web/20081205073725/http://www.wcc-coe.org/wcc/what/faith/easter.html 2008-12-05 , see also Reform of the date of Easter
1998, April 6 PBS Frontline: From Jesus to Christ
1999 International House of Prayer https://web.archive.org/web/20080315103136/http://www.ihop.org/ 2008-03-15 in Kansas City begins non-stop 24/7 continual prayer
1999, Oct 31 signing of the Joint Declaration on the Doctrine of Justification between the Lutheran World Federation and the Catholic Church
21st century
2001 The Way of the Master founded
2004 Mel Gibson's film The Passion of the Christ is released
2005 Death of Pope John Paul II, election of Pope Benedict XVI
2006, July 18 World Methodist Council voted unanimously to adopt the Joint Declaration on the Doctrine of Justification http://webarchive.loc.gov/all/20060725190303/http://www.catholicnews.com/data/stories/cns/0604186.htm 2006-07-25 
2012 Woman bishops rejected by the Church of England
2013 Pope Benedict XVI abdicates, replaced by Pope Francis.


Marie Curie: Maria Salomea Skłodowska–Curie (Marie Curie) (7 November 1867 – 4 July 1934) was a Polish physicist and chemist. She did research on radioactivity. She was also the first woman to win a Nobel Prize. She was the first woman professor at the University of Paris. She was the first person to win two Nobel Prizes. She received a Nobel Prize in physics for her research on uncontrolled radiation, which was discovered by Henri Becquerel.
She died because of too much exposure to radiation in her laboratory. She had no protection against the effects of radiation. Its effects were not understood at that time.
Early life
Skłodowska-Curie was born on 7 November 1867 in Warsaw, Poland. She lived there until she was 22. Her original name was Maria. Maria Skłodowska-Curie was the fifth child in her family. At the age of 10, her sister Zofia died. Her mother died one year later. Her father was a math teacher. As a young girl, she was interested in physics. She was top of her high school class. She graduated at 15. Maria became a teacher so she could earn money to go to school in Paris, France. She also went to an unaccredited college in Poland. 
Eventually, she left Poland and went to France under the name “Marie" after one of her big sisters gave her the chance. In Paris, she earned higher degrees and did her important scientific work. She founded the Curie Institutes in Paris and Warsaw.
Scientific career 
Marie Skłodowska-Curie and her husband created a theory of radioactivity. This was a term made by her husband Pierre Curie. They found different ways to separate radioactive isotopes and discovered two new elements: polonium, 400 times more radioactive than uranium, and radium, 5000 times more radioactive than polonium. The term polonium was named after Poland, her home country; radium named after the Greek word for ray. Radium gave rise to radiology. She used her own studies in radioactivity to develop a new treatment for cancer. These treatments use the radioactive isotopes. She was the first woman to win the Nobel Prize and the first person to win two Nobel Prizes.
 Discovery of radium 
Marie Skłodowska-Curie discovered radium. It is one of the most radioactive and dangerous metals. She shared this discovery with Pierre Curie and Gustave Bemont. The three found radium in 1898. They discovered it when using a uranium ore. It gave off a lot of radiation. They decided that it was coming from more than uranium. The group found radium in the uranium. Radium is now used for many different things. For example, doctors used to use it to kill cancer cells. Radium was found in paint and watches. Many workers who made radium-containing products developed bone cancer.
Personal life
Even though Skłodowska-Curie became a French citizen, Skłodowska-Curie never lost her Polish identity. She graduated first in her class in 1893. One year later she earned a master's degree in mathematics. Later, she met her husband, Pierre, at the Municipal School of Industrial Physics and Chemistry. They were married in July 1895 after only one year. They also started to work together on scientific discoveries. Maria and Pierre had their first daughter, Irene, in 1897. Their second daughter, Eve, was born in 1904. Pierre died on April 19, 1906, after he was hit by a horse-drawn wagon.
 Fund raising 
After the war, Maria started to raise money for a hospital. The hospital raised money for radiation research. She was invited to tour the United States to recommend and speed up her project. She sailed for the United States in 1921. She collected enough money and equipment for a new laboratory. She then started speaking at meetings to raise more money and became a celebrity. She also supported world peace by serving on the council of the League of Nations.
Death
Near the 1920s, Skłodowska-Curie and many of her colleagues began to suffer from symptoms of cancer. Skłodowska-Curie began to lose her sight. Cataract surgeries to try to bring back her sight did not help. Skłodowska-Curie knew that the element (radium) she discovered might have been causing the symptoms, but she did not want to admit it to herself or others. In the early 1930s, Skłodowska-Curie’s health started to quickly get worse. Doctors diagnosed her with pernicious anemia. Pernicious anemia is a blood anemia that happens when someone is overly exposed to radiation. The doctors didn't tell the public or Skłodowska-Curie herself what was going on. On July 4, 1934, at 66 years old, she died in a Sanitorium at the French Alps. She was then buried next to her husband in Sceaux, France. Maria Skłodowska-Curie was a physicist and chemist best known for her work on radioactivity; however, she also discovered the elements polonium and radium. She was awarded two Nobel Prizes — one in physics which she won jointly with her husband and Henri Becquerel, and another in chemistry — and was the first person to win two Nobel Prizes. She is still one of only four people (along with Linus Pauling, John Bardeen and Frederick Sanger) to accomplish that feat. Skłodowska-Curie is responsible for establishing the theory of radioactivity, but unfortunately she unwittingly also discovered the fatal effect radioactivity can have on your health; she died on July 4, 1934, of aplastic anemia caused by radiation exposure.


Ancient Egypt: Ancient Egypt, or the Kingdom of Kemet, was a society that began around 3150 BC and lasted until 30 BC, when it was invaded by the Roman Empire.
Egypt grew along the Nile River and was at its most powerful in the 2nd millennium BC. Its land stretched from the Nile Delta to Nubia, a kingdom located mostly in present-day Sudan.
With the water from the Nile, crops were generally good. They were grown after the Nile flood water went down.
The Egyptians created a way of writing using hieroglyphs. They also built huge temples and tombs, traded with other areas, and had a powerful army. 
Their religion had many gods, and its priests were powerful and rich. The Egyptian rulers, called pharaohs, were thought to be close to the gods.
 History 
 Farming begins 
People have lived along the Nile for a very long time, according to archaeologists, who study objects left by ancient people. The fertile flood plains of the Nile allowed people to begin farming. By the 10th millennium BC, the people in Egypt had begun growing cereal grains like wheat and barley. 
Because they were farming, people stayed in one place instead of living a nomadic lifestyle. Because they were settled, their society became more complex. That was an important step in the history of human civilization.
This period in Egyptian history is called "predynastic," as it happened before the large dynastic kingdoms were formed.
 Cultures develop 
By about 5500 BC, small tribes living in the Nile Valley had developed into a series of cultures. Each had begun farming crops and animals. Each had their own types of pottery and personal items, such as combs, bracelets, and beads. In Upper Egypt, the south part of the country, the Badarian was one of the earliest cultures. It is known for its high-quality pottery, stone tools, and its use of copper. It was followed by the Amratian and Gerzian cultures.
 Periods in history 
The different periods of ancient Egyptian history are:
 Predynastic Period (5500 – 3000 BC)
 Early Dynastic Period (1st & 2nd Dynasties, 3000 – 2700 BC)
 Old Kingdom (3rd to 6th Dynasties, 2700 – 2180 BC)
 First Intermediate Period (7th to 11th Dynasties, 2180 – 2050 BC)
 Middle Kingdom (11th to 14th Dynasties, 2080 – 1640 BC)
 Second Intermediate Period (15th to 17th Dynasties, 1640 – 1560 BC; the Hyksos)
 New Kingdom (18th to 20th Dynasties, 1560 – 1070 BC)
 Third Intermediate Period (21st to 25th Dynasties, 1070 – 664 BC)
 Late Period (26th to 31st Dynasties, 664 – 323 BC; the Persians)
 Greco-Roman Egypt (323 – 30 BC; Ptolemaic to Roman)
During some of the Intermediate periods, the traditional system broke down, the country was divided, or it was invaded by foreign rulers. During some periods, the Egyptian government was challenged and sometimes overthrown. Still, Egypt's culture and climate were relatively stable compared to those of other parts of the Middle East.
 Government 
 Districts 
Ancient Egypt was divided into many different districts, called sepats. The first divisions were created during the Predynastic Period, but they became small city-states that ruled themselves. 
When the first pharaoh came to power, the sepats remained and were much like the counties in many countries today. They stayed basically the same for a long time. There were 42 of them, and each was ruled by a governor, chosen by the pharaoh. In later years. the districts were called nomes, and the governor was called a nomarch.
 Taxes 
Ancient Egypt had many different taxes, but there was no real money, so people paid each other with goods or work. The person who watched the tax collection was a scribe, and every tax collector in Egypt had to state every day how many taxes they had collected. 
Each person paid different taxes based on the work that they did: for example, craftsmen paid in goods while hunters and fishermen paid with food. Every household in the country paid a labour tax every year by helping with work for the country (like mining or working on canals). Many rich Egyptians paid poorer people to do that for them.
 Language 
Ancient Egyptian language developed within six time periods.
 Archaic Egyptian (before 3000 BC) 
This language was found on pottery carvings. Archaic means 'very old.'
 Old Egyptian (3000 BC to 200 BC) 
This language was used during the Old Kingdom and First Intermediate Period. It has been found in pyramids and Egyptian tombs. It was the first version of the language that had plural tense, which shows that people were discussing more than one object at a time.
 Middle Egyptian (2000 BC to 1300 BC) 
This language is called Classic Egyptian. It is found all over objects and tombs in Egypt, including Egyptian coffins. Books on science and society were written during this time, and many of the things that we know about religion of the time are written in Classic Egyptian. Even after people stopped speaking this kind of Egyptian, writers still used it when they wrote books.
 Late Egyptian (1300 BC to 700 BC) 
This is the language of the New Kingdom, which was the best time in Egypt's history. There was a lot of knowledge being shared during this time and so we have many very old books that were written in Late Egyptian. Many people believe that this version of the language was much like what the Egyptians spoke.
 Demotic and Coptic 
Demotic Egyptian was used from around 700 BC to 400 AD.
Coptic Egyptian was used from around 300 AD to 1700 AD.
 Writing 
 Hieroglyphics 
Egypt had writing called hieroglyphics, which is one of the two oldest written languages in history. (The other is Sumerian cuneiform). Hieroglyphic writing dates to c. 3200 BC and has around 500 symbols. A hieroglyph represents a word, a sound, or a symbol to show what the sign means. The same symbol can serve different purposes in different contexts. 
Hieroglyphs on stone monuments and in tombs were for public purposes. It was art and often propaganda.
 Hieratic script 
Priests used this script for everyday writing on papyrus, wood or cloth. It was a cursive form of writing, called hieratic, which was quicker and easier. 
Formal hieroglyphs may be read in rows or columns in either direction, but are typically written from right to left. Hieratic was always written from right to left, usually in horizontal rows.
 Demotic script 
This was the script that ordinary people used. It became the main writing style in ancient Egypt. This form of writing and formal hieroglyphs accompanies the Greek text on the Rosetta Stone.
 Coptic script 
The Coptic script is a modified Greek alphabet. The Coptic language is the last stage of the Egyptian language. (Today, Egyptians speak a dialect of Arabic).
 Literature 
Some ancient Egyptian literature has survived to the present day. There are teaching texts such as the Maxims of Ptahhotep, the Instructions of Amenemope, and the Ebers papyrus. The Ebers papyrus is one of the earliest medical texts ever found.
There are also poems and stories. 
 The story of Sinuhe
An Ancient Egyptian murder mystery written around 1800 BC.
 Ipuwer papyrus
A poem about the ruin of Egyptian society--some think it is about the story in Exodus, a book in the Jewish/Christian Bible.
 Westcar papyrus
A series of stories about the Pharaoh Khufu told by his sons.
 Papyrus Harris I
The longest papyrus ever found in Egypt.
 Story of Wenamun
An ancient adventure story about a priest who goes to collect gifts from a king.
 Religion 
Religion was very important to Ancient Egyptians. The centre of any Egyptian town was the temple, a building that was used for everything from the town hall to a university in addition to its religious services.
Because they were so religious, Egyptians created a lot of art depicting many different kinds of divine (holy) creatures, including the pharaoh, who was thought to be a god.
The afterlife was also very important to Egyptians, who are known for mummifying their dead. The mummies are important to scientists today because they provide information about how the Egyptians lived.
 Gods and goddesses 
All of the gods were important, but some were more important than others. 
Isis was the goddess of the sky. Another major god was Ra, who was the god of the sun. The less well-known god of the Nile and crocodiles was named Sobek, which is a rather unusual name. 
Bastet was the goddess of cats, so the Ancient Egyptians mummified cats in her honour. She was also the goddess of protection, joy and families.
 Agriculture 
 Rich soil 
The rich fertile soil came from annual floodings of the Nile River. The ancient Egyptians were able to produce plenty of food, which allowed the population to devote more time and resources to cultural, technological, and artistic pursuits. Ancient Egyptian taxes were assessed based on the amount of land a person owned.
Most animals were kept as food. Some animals were kept as pets. All kinds of animals were important to Egypt. Ancient Egyptians understood the animals that they kept: goats, pigs, ducks, cows and geese.
 Farming 
Farming in Egypt was dependent on the cycle of the Nile. The Egyptians recognized three seasons: Akhet (flooding), Peret (planting), and Shemu (harvesting). The flooding season lasted from June to September. The flooding on the river's banks left a layer of mineral-rich silt ideal for growing crops. 
After the floodwaters had receded, the growing season lasted from October to February. Farmers plowed and planted seeds in the fields, which were irrigated with ditches and canals. Egypt receives little rainfall, so farmers relied on the Nile to water their crops.p514 
From March to May, farmers used sickles to harvest their crops, which were then threshed with a flail to separate the straw from the grain. Winnowing removed the chaff from the grain, which was then ground into flour, brewed to make beer, or stored for later use.p506
 Agricultural products 
Flax plants were grown for the fibers of their stems. The fibers were split along their length and spun into thread, which was used to weave sheets of linen and to make clothing. 
Papyrus growing on the banks of the Nile River was used to make paper. 
Vegetables and fruits were grown in garden plots, close to homes and on higher ground. They had to be watered by hand. Vegetables included leeks, garlic, melons, squashes, pulses, lettuce, and other crops. In addition, grapes were made into wine.p577; 630
 Medicine 
Ancient Egyptians had some advanced medical knowledge for their time. They performed surgery, set broken bones, and even used medicines like honey, breast milk, and gazelle's milk. These had medicinal benefits, but people also thought they kept evil spirits and demons away. 
The Edwin Smith papyrus is the world's oldest surviving surgical document, written around 1600 BC. The text provides detailed descriptions of anatomy and the examination, diagnosis, treatment, and prognosis of 48 types of medical problems.
 Pyramids 
Ancient Egyptian pyramids are shaped stone masonry structures. They are the best-known pyramid structures and are some of the largest ever buildings. Over 130 pyramids have been discovered in Egypt. Most were built on the western side of the Nile in desert areas. Egyptian pyramids are often contain chambers and passages and were built as the burial places of the Egyptian kings before the start of the Old Kingdom until the end of the Middle Kingdom. Because the Egyptians kept written records, we know about the building of some pyramids.
The Great Pyramid, at Giza, is the largest and most famous pyramid. It was built for Pharaoh Khufu. is over 140 metres high, and took 20 years to build. It is listed as one of the Seven Wonders of the World. The step pyramid at Saqqara is the earliest pyramid that is still standing today. Built in 2630 BC, it was a burial place of the Pharaoh Djoser. Its architect was Imhotep.
 Other achievements 
Engineering was an important activity in Egypt. Engineers measured and surveyed the distance between two points. They designed and made the pyramids, which are nearly perfect geometrically. They also make cement and developed large irrigation networks.
Science was also important. Mathematics was used, and the golden ratio was used in the construction of the pyramids.
Another ability of the Egyptians was glassmaking. Archaeologists have found many pieces of beads, jars, figures, and ornaments in tombs across the nation. In 2005, the remains of an ancient glassmaking factory was found.
 Timeline 
 Predynastic 
 3500 BC: Senet, a board game, is invented
 3500 BC: Egyptian faience, the world's oldest earthenware, or pottery, is created. It is not the same as modern faience pottery.
 Dynastic 
 3300 BC: Bronze works are first created
 3200 BC: Hieroglyphs are developed
 3100 BC: Decimal system in use
 3100 BC: Mining occurs on Mount Sinai
 3100 BC: Ships are built in Abydos, an Egyptian city
 3000 BC: Trading takes place between Egypt and Palestine
 3000 BC: Copper plumbing in use
 3000 BC: Papyrus, or ancient paper, is first used
 3000 BC: First documented use of medicine
 2900 BC: Perhaps the first steel use in the ancient world
 2700 BC: First surgery performed
 2700 BC: Surveying used by engineers
 2700 BC: Hieroglyphs no longer show only little pictures of words but become based on sounds
 2600 BC: The Great Pyramids of Giza created
 2600 BC: Shipping expeditions occur
 2600 BC: First use of barges
 2600 BC: Pyramid of Djoser created
 2600 BC: Menkaure's Pyramid and the Red Pyramid created
 2200 BC: Government in Egypt collapsed, meaning many different people tried to become pharaoh
 1900 BC: Possible Nile to Red Sea canal created
 1650 BC: The Rhind Mathematical Papyrus is written, which shows knowledge of geometry, arithmetic and algebra
 1600 BC: The Edwin Smith Papyrus is written, which shows knowledge of advanced medical techniques
 1550 BC: The Ebers Medical Papyrus is written, the first document on the topic of tumours
 1500 BC: Glassmaking
 1258 BC: First known peace treaty (Ramesses II)
 1160 BC: The Turin Papyrus is written, the first geologic and topographic map


History of racial segregation in the United States: Racial segregation means separating people because of their races. In the United States, racial segregation has existed since before the United States was its own country. Slavery, racist laws, racist attitudes, and many other things caused the United States to segregate white and non-white people for century. Although segregation is now against the law, racist attitudes still remain, and new forms of segregation have formed over time.
 Segregation of African-Americans 
 Background 
The first West African slaves were brought to America in 1619. This was just nine years after British settlers created the first permanent settlements in America, at Jamestown, Virginia.
People in all thirteen American colonies used slaves. Many of the Founding Fathers of the United States owned slaves, including George Washington, Thomas Jefferson, Benjamin Franklin, John Hancock, James Madison, Patrick Henry, and John Jay.
Abolitionists started trying to make slavery illegal in the mid-1700s. By 1804, all of the northern states had ended slavery. However, none of the Southern states had. The Southern states believed that slavery was their right, and they did not want to give it up. Cotton had become a very important crop in the South. Owners of large cotton plantations were used to having slaves to do work for free, which made the plantation owners richer because they did not have to pay anybody to work.pp. 232–233
Eventually, the South tried to leave the United States.p. 278 This caused the American Civil War. The North won, and in 1865, the Thirteenth Amendment to the United States Constitution made slavery illegal everywhere in the country. In 1868 and 1870, the Fourteenth and Fifteenth Amendments gave African-Americans citizenship, and gave them the right to vote.
Segregation continues in the South
Losing the Civil War did not change people's ideas about African-American people. During slavery, slave owners had not seen slaves as humans. They saw them as property, things to buy and sell, like animals you would use on a farm. After the War, many European-American people still did not see African-Americans as equal to European-Americans.
Starting in 1890, the all-white legislatures in the Southern states began to pass state laws that required segregation. These racist laws became known as Jim Crow laws. For example, blacks could not:
 Go to the same schools, restaurants, or hospitals as whites
 Use the same bathrooms as whites, or drink from the same water fountains
 Sit in front of whites on buses
In 1896, in a case called Plessy v. Ferguson, the Supreme Court ruled that these laws were legal. They said that segregation was fine, as long as things were "separate but equal." In the South, everything was separate. However, places like black schools and libraries got much less money and were not as good as places for whites. Things were separate, but not equal.
Segregation kept African-Americans from having the basic rights that the Founding Fathers had written into the Constitution of the United States. Law-makers, government officials, voting officials, and police officers were all white. This prevented African-Americans from having any say in their government; being able to get the same voting rights as European-American people; having police officers protect them; or being able to get justice for crimes against them. Because they could not count on all-white police forces to protect them, violence against African-Americans, especially lynchings, increased. Because African-Americans could not vote, they also could not serve on juries. This meant that if a black person was ever on trial for a crime, the jury would be all-white.
Across the United States
Problems were worst in the South. However, African-Americans went through different kinds of segregation in other places.
Across the United States, segregation in housing was a problem. Many African-Americans could not get mortgages to buy houses. Realtors would not sell black people houses in the suburbs, where white people lived. They also would not rent apartments in white areas. Until the 1950s, the federal government did nothing about this.
When he was elected in 1913, President Woodrow Wilson made government offices segregated. He believed that segregation was best for everyone.
Black people fought in both World War I and World War II. However, the military was segregated; black officers even had to enter some military bases through separate entrances from white officers. Black soldiers also were not given the same opportunities as white soldiers. Finally, in 1948, President Harry Truman de-segregated the military.
Early activism
African Americans tried to fight back against discrimination in many ways. Mostly, they tried to use the courts to get justice. For example, in 1909, the National Association for the Advancement of Colored People (NAACP) was created. Its goal was to end race discrimination through lawsuits, education, and lobbying.
However, eventually, many African Americans became frustrated and began to dislike the idea of using slow, legal strategies to achieve desegregation. Instead, African American activists decided to use a combination of protests, nonviolence, and civil disobedience. This is how the Civil Rights Movement of 1954-1968 began.
Civil Rights Movement
From about 1954 to 1968, many African-American people and white allies fought to end racial segregation. The movement depended on non-violent protests, sit-ins, marches, civil disobedience, and lawsuits. Its victories included:
 Brown v. Board of Education (1954) which made segregation in schools illegal
 The Montgomery Bus Boycott (1955-1956), which ended all bus segregation in Alabama
 Getting federal soldiers to de-segregate Little Rock Central High School for its first nine black students (1957)
 Sit-ins (1958-1960), which de-segregated some stores, lunch counters, and other places throughout the country
 Getting United States Soldiers to force the Mississippi Southern College and the University of Alabama to let in their first black students
 De-segregating businesses in downtown Birmingham, Alabama
 Getting the Civil Rights Act of 1964, the Voting Rights Act of 1965, and the Civil Rights Act of 1968 passed. These federal laws made it illegal to discriminate against black people, keep them from voting, and keep them from having fair housing
These victories were not easy. Protesters were often threatened and attacked. Leaders' homes were bombed. In Birmingham, the police attacked protesters, including children, with police dogs and fire hoses, then took them to jail. In other cities, police beat protesters with clubs and fired into student protests. Three of the movement's leaders Martin Luther King, Jr., Malcolm X, and Medgar Evers were murdered.
Nobody knows exactly how many people were killed during the Civil Rights Movement. However, at least 37 people were murdered, either because they were doing civil rights work, or because racist white groups like the Ku Klux Klan and the White Citizens' Council wanted to terrorize black people.See the "Deaths" section of the Civil Rights Movement page for additional citations and details. Twelve of these people were children or teenagers when they were murdered.
Eventually, the Movement was successful in removing the laws that allowed segregation. However, attitudes are harder to change, and racism still exists in the United States.
Single parenthood
One study finds that African Americans who live in segregated metro areas have a higher likelihood of single-parenthood than blacks who live in more integrated places. Those in poverty also show an increased chance in becoming single parents.
Public spending
Research shows that segregation along racial lines contributes to public goods inequalities. Whites and blacks are vastly more likely to support different candidates for mayor than whites and blacks in more integrated places, which makes them less able to build consensus. The lack of consensus leads to lower levels of public spending.
Costs
In April 2017, the Metropolitan Planning Council in Chicago and the Urban Institute, a think-tank located in Washington, DC, released a study estimating that racial and economic segregation is costing the United States billions of dollars every year. Statistics (1990–2010) from at least 100 urban hubs were analyzed. This study reported that segregation affecting Blacks economically was associated with higher rates of homicide.
Segregation of Native Americans
In the early 1800s, the United States was growing farther into the South. European-Americans wanted more land to plant cotton. However, many different Native American tribes lived in the lands the United States wanted to take over.
Andrew Jackson was a big supporter of "Indian removal" convincing or forcing Native Americans to leave the South and move west, outside of the United States. First as a Major General in the United States Army, and then as President, he led the United States' "Indian removal" program.
Indian removal
The program started in 1814, when Jackson led a group of soldiers who defeated the Creek Indians. He forced them to sign a treaty giving up over 20 million acres of their land to the United States. Over the next ten years, Jackson got nine other tribes to sign treaties giving up their land.
In 1829, Jackson became President. That same year, gold was found in Georgia, which caused a gold rush. This only made white people in the United States want control of the South even more. In 1830, Jackson passed the Indian Removal Act of 1830. This law said Jackson could give land west of the Mississippi River to Indian tribes if they agreed to give up their lands in the South. The law promised the tribes that they could live on their new lands forever, and be protected by the United States government. By the time his presidency ended in 1837, Jackson had gotten Native Americans to sign almost 70 treaties giving up their land. Almost 50,000 Native Americans moved to "Indian Territory" west of the Mississippi River. However, the government already had a plan to force them into a smaller area, in what is now eastern Oklahoma.
The Trail of Tears
The Cherokee Nation refused to leave their lands. They even got the United States Supreme Court to rule that they were sovereign and did not have to follow the laws of the United States. Jackson simply ignored this ruling. In 1835, he got a small group of Cherokee to sign a treaty agreeing to leave their lands. The rest of the Cherokee Nation tried to keep their lands. However, in 1838, the United States Army and the Georgia militia forced them to leave their lands. On what is known as the "Trail of Tears," about 15,000 Cherokee were forced to walk over 2,000 miles to Oklahoma. About 4,000 died along the way.
By the 1840s, except for a few Seminole Indians living in Florida, there were no Native Americans left in the American South.
Reservations
In 1851, the United States Congress passed a law that created Indian reservations in Oklahoma. European settlers had already begun to move into the lands the Native Americans had been forced to move to. This was causing conflicts between European Americans and Native Americans. The goal of the reservations was to segregate the Native Americans from European settlers.
In 1868, President Ulysses S. Grant decided to create more reservations, and force Native American tribes that lived in the west to move to them. Along with segregating the Native Americans and clearing their land for white use, Grant planned to have church officials run the reservations so they could teach Christianity to the tribes.
Many tribes refused to leave their lands, and were forced onto reservations by the United States Army. If Native Americans left their reservations, the Army went after them to try to force them back onto the reservations. This led to massacres of Native Americans, and some wars.
In 1887, Congress passed the Dawes Act. This law stopped giving land to whole tribes, and broke up the land into small pieces for individual families to use for farming. Natives who took the land, started living alone instead of with their tribes, and started farming were viewed as "civilized," and they were made United States citizens. Indians who refused to segregate themselves even more on small pieces of land were not allowed to be citizens. Whatever land was left was sold to white settlers, which made the reservations even smaller.
It was not until 1975 that the Supreme Court ruled that tribes are sovereign over tribal lands and members of the tribe.
As of 2015, all of the Indian reservations in the United States, together, make up 87,800 square miles an area about the size of Idaho. However, Native Americans are now allowed to live or work anywhere they want to, and as of 2016, more than half have left the reservations.
 Japanese-American internment 
On December 7, 1941, Japan attacked Pearl Harbor in Hawaii and declared war on the United States. This caused the United States to enter World War II and start fighting Japan, as well as Nazi Germany and Italy.
In February 1942, President Franklin D. Roosevelt signed an order that allowed the military to force people to leave the West Coast. However, Japanese-Americans were the only people on the West Coast who were forced to leave. They were given 48 hours to leave their homes for internment camps. These were camps where Japanese-Americans were kept separate from everybody else. The camps were surrounded by barbed wire and guarded by soldiers with guns.
The United States government forced over 110,000 Japanese-American people into internment camps. (This was over 80% of the Japanese-American people who lived in the continental United States at the time.) More than three out of every five of these people were born in the United States, and were United States citizens. About half were children.
Because the United States was fighting Nazi Germany and Italy as well as Japan, some German-Americans and Italian-Americans were forced into internment camps too. So were some Jewish refugees from Nazi Germany. However, none of this was as common as it was with Japanese-Americans.
In 1945, the year World War II ended, the United States let people out of the camps. However, many of the people who were interned had lost everything they had. In 1988, the United States government finally apologized and said there was no reason for the internment other than racism.


India: yes
July 2025
June 2024
July 2022 
India (hi भारत 85% Bhārat Gaṇarājya) officially the Republic of India, also known as Hindustān, is a country in South Asia. It is the seventh-largest country by area. It is also the most populated country in the world. It is the world's largest democracy by number of people since 1947.Metcalf Metcalf 2012 327 : "Even though much remains to be done, especially in regard to eradicating poverty and securing effective structures of governance, India's achievements since independence in sustaining freedom and democracy have been singular among the world's new nations."Fisher 2018 184–185 : "Since 1947, India's internal disputes over its national identity, while periodically bitter and occasionally punctuated by violence, have been largely managed with remarkable and sustained commitment to national unity and democracy."
India is a peninsular country. It has the Indian Ocean to the south, the Arabian Sea in the southwest, the Bay of Bengal in the southeast, and the Himalayas up north. It has six neighbours: Pakistan in the northwest;The Government of India also gives Afghanistan as a neighbouring country. It claims all of Kashmir as the part of India. But Pakistan disputes this claim. Pakistan controls the region of Kashmir bordering Afghanistan. Source: China, Nepal and Bhutan in the north; and Bangladesh and Myanmar in the east. Sri Lanka and the Maldives are nearby to the south. Its Andaman and Nicobar Islands share water borders with Indonesia, Myanmar and Thailand.
Humans came to the Indian subcontinent from Africa more than 55,000 years ago. They have lived there for long time. At first, they had lived in the subcontinent as hunter-gatherers. The Indian subcontinent is the second most diverse region after Africa. Humans began to create settlements in the subcontinent 9,000 years ago, on the western banks of the Indus River. The settlements became parts of the Indus Valley Civilisation in the third millennium BCE. By 1200 BCE, Sanskrit, an Indo-European language, spread to India from the northwest. The first presence of Sanskrit is found in the hymns (songs of worship) of the Rigveda. The hymns were spread from one person to another orally, not by any book. They show the early forms of Hinduism. The Indo-Aryan languages replaced the Dravidian languages in the northern and western regions of India. By 400 BCE, the caste system was developed within Hinduism. Buddhism and Jainism were also developed in India at the same time.
India has been a federal republic since 1950. Its government is a democratic parliamentary system. It is a multilingual (multiple languages) and multicultural (multiple cultures) society. The capital city of India is New Delhi. India has the second largest military force in the world and is also a nuclear weapon state. India's economy became the world's fastest growing in the G20 developing nations during 2014, replacing the People's Republic of China. India's literacy and wealth are also rising.
India has the fourth largest economy by nominal GDP, the third largest by GDP (PPP) and is one of the fastest growing major economy. According to New World Wealth, India is the fifth richest country in the world with a total individual wealth of $12.6 trillion. However, it still has many social and economic issues, for example poverty, pollution, social equality, religious extremism, terrorism and corruption. India has reduced its rate of poverty. But its economic inequality has increased. 
India is a founding member of the World Trade Organisation (WTO), and has signed the Kyoto Protocol. It is also a member of the G20 developing nations. India has its own space agency (ISRO). It has done much research throughout the Solar System. It has sent spacecraft to the Moon and Mars. Indian movies, music and spiritual teachings are becoming more important in global culture. Sources describe it as a potential superpower, because of its rising economy and increase in global influence. India is a country with nuclear weapons. It also has a high rank in military expenditure. It has disputes over Kashmir with its neighbours, Pakistan and China, since the middle of the 20th century. 
India has the fourth largest number of spoken languages per country in the world, only behind Papua New Guinea, Indonesia, and Nigeria. Most of Indians follow Hinduism at 80%, but people of different religions such as Buddhism, Sikhism and Islam also live there.
Origin of the name
The Oxford English Dictionary (third edition - 2009) says that the name "India" comes from the Classical Latin name India. It was originally used for the Indian subcontinent and the areas to its east. Latin took the name from Hellenistic Greek India (Ἰνδία), from ancient Greek Indos (Ἰνδός) and then from Old Persian Hinduš. The Old Persian name was used for the eastern province of the Achaemenid Empire. The name has a relation with the Sanskrit word sindhu. It means "river", especially the Indus River.Thieme 1970 447–450 The ancient Greeks called Indians as Indoi (GRC Ἰνδοί), which means "the people of the Indus".Kuiper 2010 86
The name Bhārat (hi भारत; ˈbʱaːɾət pron hi-Bharat.ogg) is found in both Indian epic poetry and the Constitution of India.Clémentin-Ojha 2014 It is used in different Indian languages in different forms. Bhārat is a modern form of the older name Bharātavarṣa (sa भारतवर्ष). It original meaning was the northern part of India.Singh 2017 253 It has become a very popular name for India since the middle of the 19th century.Clémentin-Ojha 2014Barrow 2003
Hindustān (ɦɪndʊˈstaːn Hindustan.ogg) is a Middle Persian name for India. It became popular by the 13th century. It is used widely since the Mughal Empire.
 History 
 Ancient India 
In 300 BCE, a king named Chandragupt Maurya built the Maurya Empire and under Ashoka united most of the Indian subcontinent under a centralized state.
One of the oldest languages of the world, Tamil, was born in today's India. It is more than 3000 years old. 
 Indian Empires & dynasties 
The Gupta Empire managed to reunite large parts of the Indian subcontinent after the collapse of the Mauryan Empire. The Gupta period is traditionally considered India's Golden age as there were great developments in culture, religion and Mathematics. 
There were also many other Indian dynasties (empires) such as the Chalukyas, Cholas, Pallavas, and Pandyas. Southern India at that time was famous for its science, art, and writing. 
The Cholas of Thanjavur were pioneers at war in the seas and influenced Malaya, Borneo, Cambodia. The influence of Cholas are still noticeable in Southeast Asia.
The Vijayanagara empire was another significant Indian empire. 
In the 16th century India came under Mughal rule. The Taj Mahal was built during the Mughal period. 
As Mughal rule weakened other empires like the Maratha empire and Sikh empire replaced it. 
 British Raj 
In the 1600s, India came under European colonization, and by 1856 the British controlled most of India.
British Colonial exploitation resulted in the deaths of millions of Indians due to starvation and famine. The British also introduced railways and banned Widow burning.
In the early 1900s, millions of people peacefully started to protest against British rule. One of the people who led the freedom movement was Mahatma Gandhi, who only used peaceful tactics, including a way called "ahimsa", which means "non-violence". 
On 15 August 1947, India peacefully became free and independent from the British Empire. India's constitution was founded on 26 January 1950. Every year, on this day, Indians celebrate Republic Day. The first official leader (Prime Minister) of India was Jawaharlal Nehru.
 After independence 
After 1947, India had a socialist planned economy. It is one of the founding members of the Non-Aligned Movement and the United Nations. It has fought many wars since independence from Britain, including wars in 1947-48, 1965, 1971, and 1999 with Pakistan and in 1962 with China. India also fought a war to capture Goa, a Portuguese-built port and a city that was not a part of India until 1961. The Portuguese refused to give it to India, so India used force and defeated the Portuguese. 
India’s early general elections saw the Congress Party, led by Jawaharlal Nehru, dominate until his death in 1964. Lal Bahadur Shastri briefly took over, followed by Indira Gandhi, who won elections in 1967 and 1971. After declaring a state of emergency in 1975, public dissatisfaction led to the Congress losing power in 1977, with the Janata Party taking over. However, this government lasted only about two years, with Morarji Desai and Charan Singh serving as prime ministers. 
Congress returned to power in 1980, and after Indira Gandhi’s assassination in 1984, her son Rajiv Gandhi won a landslide election. The party lost again in 1989, with a short-lived National Front coalition government under V.P. Singh and Chandra Shekhar. By 1991, no party secured a majority, but Congress formed a minority government led by P.V. Narasimha Rao.
India performed nuclear tests in 1974 and 1998. It is one of the few countries that have nuclear bombs. 
Since 1991, India has been one of the fastest-growing economies in the world.
Geography
India is the seventh biggest country in the world by land. It is the main part of the Indian subcontinent. The countries next to India are Pakistan, Bangladesh, Myanmar, China, Bhutan and Nepal. It is also near Sri Lanka and the Maldives, two island countries. The Andaman and Nicobar Islands, a union territory of India, is near Thailand, Indonesia and Myanmar.
 Terrain 
There are many mountains in the northern part of India. The most famous mountain range there is the Himalayas, which have some of the tallest mountains in the world. 
There are many rivers in India. The main rivers are the Ganges, the Brahmaputra, the Yamuna, the Godavari, the Kaveri, the Narmada, and the Krishna.
 Coastline 
India is a peninsula, which means that it is surrounded on three sides by water. In the west is the Arabian Sea, in the south is the Indian Ocean, and in the east is the Bay of Bengal.
India's total coastline is 7517 km mi -2 on off long. The mainland's coastline is 5423 km mi -2 on off long. The Andaman, Nicobar and Lakshadweep islands have 2094 km mi -2 on off long coastlines in total.Kumar Pathak Pednekar Raju 2006 
Based on Indian naval hydrographic charts, 43% of the mainland coast are sandy beaches, 11% are rocky shores and cliffs, and 46% are mudflats or marshy shores.Kumar Pathak Pednekar Raju 2006
 Climates 
India has different climates. In South India, the climate is mainly tropical, which means it can get very hot in summer and cool in winter. The northern part, though, has a cooler climate, called subtropical. The mountainous regions can be alpine. The Himalayas, in the alpine climate region, can get extremely cold. 
The Himalayas block cold Central Asian winds from blowing into the Indian subcontinent. It keeps the most of the subcontinent warmer than most places at same latitudes.Posey 1994 118Wolpert 2003 4 
There is very heavy rainfall along the west coast and in the Eastern Himalayan foothills. The west, though, is drier. 
 Monsoon 
Because of some of India's deserts, the entire country gets rain for four months of the year. That time (usually around June to September) is called the monsoon. It happens because the deserts attract water-filled winds from the Indian Ocean, which give rain when they come into India. 
When the monsoon rains come late or not so heavily, droughts (when the land dries out because there is less rain) are possible.
Politics
1
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 Rashtrapati Bhavan Wide New Delhi India.jpg
 The Rashtrapati Bhavan in New Delhi is the official residence (house where a person lives) of the President of India.
 Glimpses of the new Parliament Building, in New Delhi (2).jpg
 The Parliament House (Sansad Bhavan) in New Delhi is the place where the Parliament of India meets. 
India is a parliamentary republic with a multi-party system.Burnell Calvert 1999 125 It is the largest democracy in the world by the number of people. It has sixnational parties, for example the Indian National Congress (INC) and the Bharatiya Janata Party (BJP). It also has more than 50regional parties.Election Commission of India The Congress is known as centre in Indian political culture, while the BJP is known as right-wing.Malik Singh 1992 318–336Banerjee 2005 3118 The Congress was the majority in the Parliament from 1950 to the end of the 1980s. From the end of the 1980s, the BJPSarkar 2007 84 and the powerful regional parties are getting more seats in the Parliament over time. This forced the national parties to create coalition governments.Chander 2004 117
Government
India is ruled under the Constitution of India. It is the country's highest document of law. It came into effect on 26 January 1950.Pylee 2003a 4 Its original form said that India would be a "sovereign, democratic republic". In 1971, the statement was changed to "sovereign, socialist, secular, democratic republic".Dutt 1998 421 
India has been said to be a "quasi-federal" form of government. That means a strong federal government with weak state governments.Wheare 1980 28 The federal government is often called the "union government" or the "central government". But after political, economic and social changes at the end of the 1990s, the government became federal.Echeverri-Gent 2002 19–20Sinha 2004 25
 Branches of government 
The union government is divided into three parts: the legislature (the one that make laws), the executive (the one that applies laws), and the judiciary (the one that makes sure that the laws are obeyed). All three parts are in New Delhi, the capital city of India.
The legislature of India is called the Parliament (hi संसद hi ISO Sansad). It is divided into two houses: the upper house Rajya Sabha (Council of States); and the lower house Lok Sabha (House of the People).Gledhill 1970 127 The Rajya Sabha has 245 members. They remain members for six years.Sharma 2007 161 Most members are elected indirectly by the legislatures of state and union territories.Sharma 2007 162 The Lok Sabha has 545 members. They remain members for five years. They are elected directly by the people's vote.Sharma 2007 143
The executive is made up of the President, the Vice President, the Prime Minister and the Union Council of Ministers. The President is the head of state of India.Sharma 2007 31 The presidents are elected by an electoral college for a period of five years. The electoral college is made up of members of central and state legislatures.Sharma 2007 138Gledhill 1970 112 The Prime Minister is the head of government of India. The President can choose the Prime Minister, who has most of the power.Sharma 2007 162 The President has less power than the Prime Minister. The Union Council of Ministers helps the Prime Minister. It is similar to a cabinet in many countries.
The judicial branch is made up of three types of courts of law: the Supreme Court, the 24 High Courts and a number of trial courts.Neuborne 2003 478 The Chief Justice of India is the head of the Supreme Court. The members of the court have the power to stop a law being passed by Parliament if they think that the law contradicts (opposes) the Constitution.Sripati 1998 423–424 They can make any government action invalid if it contradicts the Constitution.Pylee 2003b 314
Divisions
For administration purposes, India has been divided into smaller pieces. Most of these pieces are called states; others are called union territories. In total, there are twenty-eight states and eight union territories.
States and union territories differ in the way they are represented. Most union territories are ruled by administrators (called Lieutenant Governors) sent by the central government. All the states (and the territories of Delhi and Puducherry) elect their local government themselves. 
States:
Union territories:
 Military 
The Indian Armed Forces is the country's military. It is made up of an Army, Navy and Air Force. There are other parts like Paramilitary and Strategic Nuclear Command. Its Commander-in-Chief is the President of India, but the Ministry of Defence manages the military. 
In 2010, the Indian Armed Forces had 1.32 million active personnel, making it one of the largest militaries in the world.
The Indian Army is becoming more modern by buying and making new weapons. It is also building defenses against missiles of other countries. In the years 2018-2022, India imported more arms than any other nation in the world. Since its independence in 1947, India fought four wars with Pakistan and a war with China.
 National symbols 
 Emblem 
The national emblem of India shows four lions standing back-to-back. The lions symbolize power, pride, confidence, and courage. Only the government can use this emblem, according to the State Emblem of India (Prohibition of Improper Use) Act, 2005.
 Name 
The name India comes from the Greek word Indus. This came from the word sindhu, which, over time, turned into Hind, Hindi, or Hindu. 
The preferred endonym (the name given to the country by its own people) is "Bhārat" in Hindi and other Indian languages. This differs with names that outsiders use for the country.
 Symbols 
Some of the national symbols are:
 National anthem: Jana Gana Mana
 National song: Vande Mataram
 National animal: Tiger
 National bird: Peacock
 National flower: Lotus
 National tree: Banyan
 National river: Ganges (Ganga)
 National Aquatic Animal: Ganges River Dolphin
 National fruit: Mango
 National heritage animal: Elephant
 National heritage bird: Indian eagle
 Border disputes 
Different countries disagree about where India's borders lie. For example, India claims Jammu and Kashmir as an Indian state. However, Pakistan and China do not recognise this area as part of India. Similarly, the Republic of India does not recognise the Pakistani and Chinese parts of Kashmir.
In 1914, British India and Tibet agreed on the McMahon Line, as part of the Simla Accord. Indians and Tibetans see this line as the official border. However, in July 1914, China withdrew from the agreement. Neither mainland China nor Taiwan recognize that Arunachal Pradesh belongs to India. According to them, it is a part of South Tibet, which belongs to China.
 Economy 
 Growth 
India's economy is among the world's fastest growing. It is the 7th largest in the world with a nominal GDP of $2,250 billion (USD). In terms of PPP, the economy is 3rd largest (worth US$8.720 trillion). The growth rate is 8.25% for fiscal year 2010. However, that is still $3678 (considering PPP) per person per year. 
 Sectors 
India's economy is based on:
 Service sector: 43%
 Industries: 41%
 Information technology: 7%
 Farming: 7%
 Outsourcing: 2%.
India's economy is diverse. Major industries include automobiles, cement, chemicals, consumer electronics, food processing, machinery, mining, petroleum, pharmaceuticals, steel, transportation equipment, and textiles.
 Poverty 
Despite its economic growth, India continues to suffer from poverty. Over one quarter of the population (27.5%) was living in poverty in 2004–2005. In 2007-2008, 80.4% of the population lived on less than US $2 a day. By 2009, this number had decreased to 68%.
 People 
There are 1.4 billion people living in India. In 2023, India passed China to become the world's most populous country. About 65% of Indians live in rural areas, or land set aside for farming. The largest cities in India are Mumbai, Kolkata, Delhi, Chennai, Bangalore, Hyderabad, and Ahmedabad. Hindi and English are Official languages of India. India has 23 officially recognised languages. Altogether, 1,625 languages are spoken in India.
 Languages 
 Language families 
There are many different languages and cultures in India. There are two main language families in India, the Indo-Aryan and the Dravidian languages. About 69% of Indians speak an Indo-Arayan language, and about 26% speak a Dravidian language. Other languages spoken in India come from the Austro-Asiatic group. Around 5% of the people speak a Tibeto-Burman language.
 Hindi & English 
Hindi is the official language in India with the largest number of speakers. It is the official language of the union. Native speakers of Hindi represented about 41% of the Indian population in the 2001 Indian census. 
English is also used, mostly for business and in administration. It has the status of a 'subsidiary official language'. 
 Other languages 
The constitution also recognises 21 other languages - either because many people speak them, or because they are very important for Indian culture. There may be as many as 1,652 different dialects in India.
In the south of India, many people speak Kannada, Telugu, Tamil and Malayalam. In the north, many people speak Punjabi, Bengali, Gujarati, and Marathi, Odia, and Maithili.
India has 23 official languages. Its constitution lists the name of the country in each of the languages. Hindi and English (listed in boldface) are the "official languages of the union" (Union meaning the Federal Government in Delhi); Tamil, Sanskrit, Telugu, Kannada, Malayalam, and Odia are officially the "classical languages of India."
 Culture 
Religion in India
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 Religion
 Percent
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Cave paintings from the Stone Age are found across India. They show dances and rituals and suggest there was a prehistoric religion. During the Epic and Puranic periods, the earliest versions of the epic poems Ramayana and Mahabharata were written from about 500–100 BCE, although these were orally transmitted for centuries before this period. Other Indian Stone Age sites apart from Pakistan are in modern India, such as the Bhimbetka rock shelters in central Madhya Pradesh and the Kupgal petroglyphs of eastern Karnataka, contain rock art showing religious rites and evidence of possible ritualised music.
Several modern religions are linked to India, namely modern Hinduism, Jainism, Buddhism and Sikhism. All of these religions have different schools (ways of thinking) and traditions that are related. As a group they are called the Eastern religions. The Indian religions are similar to one another in many ways: The basic beliefs, the way worship is done and several religious practices are very similar. These similarities mainly come from the fact that these religions have a common history and common origins. They also influenced each other.
The religion of Hinduism is the main faith followed by 79.80% of people in the Republic of India; Islam – 14.23%; Christianity – 2.30%; Sikhism – 1.72%; Buddhism – 0.70% and Jainism – 0.37%.
 Technology 
India sent a spacecraft to Mars for the first time in 2014. That made it the fourth country and first Asian country to do so, successfully. It was called the Mars Orbiter Mission.
ISRO launched 104 satellites in a single mission to create a world record. India became the first nation in the world to have launched over a hundred satellites in one mission. That was more than the 2014 Russian record of 37 satellites in a single launch.
This historic event of Chandrayaan-III successfully landed on the South Pole of the moon, being the first one to do so.
 Pop culture 
India has the largest movie industry in the world. The Hindi film industry is known as Bollywood, and is mainly based in Bombay, now known as Mumbai. Other industries include Tollywood, Kollywood, Sandalwood, Mollywood, Jollywood, Dhollywood, etc. It makes 1,000 movies a year, about twice as many as Hollywood.
 Sports 
 Cricket 
Cricket is the most popular sport in India. The Indian cricket team won the 1983 and 2011 Cricket World Cup and the 2007 ICC World Twenty20. They shared the 2002 ICC Champions Trophy with Sri Lanka and won the 2013 ICC Champions Trophy and 2025 ICC Champions Trophy. 
Cricket in India is controlled by the Board of Control for Cricket in India or BCCI. Domestic tournaments are the Ranji Trophy, the Duleep Trophy, the Deodhar Trophy, the Irani Trophy, and the Challenger Series. There is also the Indian cricket league and Indian premier league Twenty20 competitions.
 Other sports 
Indians have excelled in hockey. They have also won eight gold, one silver, and two bronze medals at the Olympic Games. 
Tennis has become popular due to the victories of the India Davis Cup team. 
Association football is also a popular sport in northeast India, West Bengal, Goa and Kerala. The Indian national football team has won the South Asian Football Federation Cup many times. 
Chess, which originated in India, is also becoming popular. The number of Indian Grandmasters has increased recently. 
Traditional sports include kabaddi, kho kho, and gilli-danda, which are played throughout India.


Michael Jackson: the British writer Michael Jackson (writer)
Michael Joseph Jackson (August 29, 1958 – June 25, 2009), also commonly known by his initials MJ, was an American singer-songwriter, dancer, composer, arranger, record producer, actor, businessman, and philanthropist. Dubbed the "King of Pop", he is regarded as one of the most culturally significant figures of the 20th century. Over a four-decade career, his music achievements broke racial barriers in America and made him a dominant figure across the world. Through songs, stages, and fashion, he proliferated visual performance for artists in popular music; popularizing street dance moves including the moonwalk, the robot, and the anti-gravity lean. Jackson is often deemed the greatest entertainer of all time based on his acclaim and records.
The eighth child of the Jackson family, Michael began performing in 1964 with his brothers in the Jackson 5 (later known as the Jacksons) at the age of 6. After signing with Motown in 1968, they gained worldwide fame with him as the group's lead singer and recorded multiple successful singles. In the early 1970s, he began his solo career, releasing the albums Got to Be There and Ben (both 1972), Music & Me (1973), and Forever, Michael (1975). Later, he rose to global stardom with the release of the albums Off the Wall (1979), Thriller (1982), Bad (1987), Dangerous (1991), HIStory: Past, Present and Future, Book I (1995), and Invincible (2001). When he died in 2009 at age 50, he had spent 44 years working in the music industry. 
Jackson remains a global figure in popular culture. He created some of the best-selling albums in music history. His contributions to music, dance, and fashion had a major cultural impact. Finally, his highly publicized personal life kept him in the public eye. Jackson died in 2009 from an overdose of propofol administered by Dr. Conrad Murray. Murray's trial was widely publicized, and he went to prison for involuntary manslaughter. Jackson's legacy lives on.
Jackson influenced artists across many music genres. Through stage and video performances, he popularized complicated dance moves such as the moonwalk, the robot, and the anti-gravity lean. Jackson is the most awarded individual music artist in history. His awards include 15 Grammy Awards, 6 BRIT Awards, a Golden Globe, 39 Guinness World Records, including "Most Successful Entertainer of All Time". He is included in the Rock and Roll Hall of Fame, the Vocal Group Hall of Fame, the Songwriters Hall of Fame, the National Rhythm & Blues Hall of Fame, and the Dance Hall of Fame. Jackson is one of the best-selling music artists of all time, with estimated sales of over 500 million records worldwide. 
Early life and career
Early life
Michael Joseph Jackson was born to a family of Jehovah's Witnesses on August 29, 1958, at St Mary's Mercy Hospital in Gary, Indiana. He was the eighth of Katherine and Joe Jackson's ten children. 
Jackson's father Joseph was a steel mill worker who played guitar in a rhythm and blues band to earn extra money for the family.
 1964: The Jackson Brothers 
On January 1, 1964, Jackson and his brother Marlon joined The Jackson Brothers, a band that their older brothers Jackie, Tito, and Jermaine had started. When they did their first public performance, Jackson was just five years old.
When Jackson was 8, he and Jermaine became the group's main singers. The group's name then changed to The Jackson 5. 
 1965: The Jackson 5 
See the main article: The Jackson 5 
The members of the Jackson 5 were the same as the "Jackson Brothers": Jackie, Tito, Jermaine, Marlon, and Michael Jackson.
The group won an important talent show in 1966. Two years later they were signed to a famous record label called Motown Records. Their first Motown single I Want You Back reached No. 1 in the Billboard Hot 100, a list of the 100 top songs in the United States.
They became quite popular and performed many original songs, including "ABC" and "I'll Be There". They were managed by their father Joe Jackson, who was very strict.
 1971-1973 
In 1971, Jackson embarked on his solo career and released his studio albums Got to Be There and Ben (both in 1972), and Music & Me (1973).
Got to Be There produced the song of the same name, as Jackson's debut solo single. Ben released one single, the title track "Ben", which was a commercial success.
1974-1981
In 1974, Jackson hosted the first American Music Awards with Donny Osmond, Rodney Allen Rippy, and Ricky Segall.
In June 1975, the Jackson 5 left Motown for CBS Records and changed their name to "The Jacksons". That same year, he released his fourth solo studio album Forever, Michael.
In 1976, The Jacksons got their own TV show on CBS. The show was cancelled in March 1977.
On October 24, 1978, a movie called The Wiz was released. The movie was a remake of The Wizard of Oz with all black actors. Jackson acted as the Scarecrow.
On December 17, 1978, The Jacksons' twelfth album was released. It was the first album they had produced. Jackson wrote the album's second single "Shake Your Body (Down to the Ground)" with Randy Jackson. It reached No.7 on the Billboard Hot 100.
In December 1978, Jackson started making his fifth and first solo album on Epic Records: Off the Wall with record producer Quincy Jones. It was released on August 10, 1979. The album got good reviews and a Grammy Award for Best Male R&B Vocal Performance.
The Jacksons' thirteenth album, Triumph, was released in 1980.
 1982-1983 
In 1982, Jackson made "Someone in the Dark" for the E.T.: the Extra-Terrestrial soundtrack. It won a Grammy for Best Recording for Children in 1984.
On October 18, 1982, the first single from his sixth studio album Thriller, "The Girl Is Mine", was released. It was sung with Paul McCartney. Some people thought that the album wasn't going to be very good because of the song.
On November 30, 1982, Thriller was released, which went on to become the best-selling album of all time. Jackson didn't do a tour to promote the album. The album sold around 70 million copies worldwide.
Thriller includes famous songs like "Beat It" and "Billie Jean" and "Thriller".
"Thriller" has a unique music video, in which shows Jackson and others dancing like zombies. The popularity of these videos helped bring the television channel MTV to fame. 
That year, Jackson won seven other Grammys for his studio album Thriller. 
In 1983, Jackson wrote three songs with Queen's lead singer Freddie Mercury. That same year, he performed "Billie Jean" during an NBC special called Motown 25, Yesterday, Today, Forever, where he debuted the "moonwalk", in which became his signature dance move in his repertoire.
1984-1985
 Pepsi commercial 
On January 27, 1984, Michael's hair caught on fire while he was filming a Pepsi Cola commercial with the rest of The Jacksons. He received severe burns and was rushed to the hospital.
Pepsi paid $1.5 million to Jackson, who gave it to the Brotman Medical Center in Culver City, California. The accident left him with severe chronic pain, and he started taking narcotic pain medications. 
 Songs and albums 
In May 1984, "Farewell My Summer Love", a song that Jackson wrote it 1973, was released as a single. It reached number seven in the UK Singles Chart.
"Somebody's Watching Me", a single by Rockwell with Jackson singing on the chorus, was released January 14, 1984. It reached number one in Spain and France.
The Jacksons' album Victory was released on July 2, 1984. Between July and December 1984 Jackson toured with his brothers. He won eight awards at the 1984 American Music Awards, the most anyone has ever won at once. He also won Best International Solo Artist and Best International Album at the BRIT Awards.
Jermaine Jackson released his tenth album, Jermaine Jackson. Michael sang on a song from the album, "Tell Me I'm Not Dreaming' (Too Good to Be True)". It was nominated for Best R&B Performance by a Duo or Group with Vocals at the 1985 Grammy Awards.
In August 1985, Jackson bought music publisher ATV Music for $47.5 million. They owned the rights to The Beatles.
Jackson wrote "We Are the World" with Lionel Richie in 1985. The song was recorded by USA for Africa. It was released as a single around the world to raise money to give to starving people in Africa. It sold over 20 million copies. It also won four Grammy Awards.
1986-1990
In August 1987, his seventh studio album Bad, was released. Jackson wanted it to sell 100 million copies; it has sold over 45 million. 
Five of Bad's seven singles were No.1 in the U.S.:"I Just Can't Stop Loving You", "Bad", "The Way You Make Me Feel", "Man in the Mirror" and "Dirty Diana". Until Katy Perry's success with her 2010 album Teenage Dream, Jackson was the only musician to ever have had that many singles from one album be No.1. 
From September 1987 to January 1989, Jackson did the Bad World Tour. This was the first tour he did on his own. 
In 1988, Moonwalk, a book Jackson wrote about his life, was published. It took Jackson four years to write. The book sold 200,000 copies. Jackson then made and released Moonwalker. In 1989, some video games about the movie were released by U.S. Gold.
In 1986, Disneyland and Epcot started showing a short film called Captain EO that starred Jackson. 
Jackson sang "You Were There" at Sammy Davis Jr.'s 60th birthday celebration. He was nominated for an Emmy Award for his performance.
The Jacksons released their last album, 2300 Jackson Street, in 1989. Michael sang on the album's second single "2300 Jackson Street" with his brothers and two of their sisters, Janet and Rebbie. Michael was also in the song's music video.
Jackson won the Grammy Award for Best Music Video, Short Form in 1989 for "Leave Me Alone".
1991-1993
On November 26, 1991, Jackson released his eighth studio album, Dangerous. It is a new jack swing album produced with Teddy Riley. Jackson included a rapper on the album for the first time and nine singles from the album. It contains the number-one single "Black or White". 
On June 27, 1992, Jackson started the Dangerous World Tour. Its goal was to raise money for charities such as the Heal the World Foundation. Jackson promised to donate all of the tour's income to charitable organizations. Jackson performed to 3.5 million people in 70 concerts, and grossed $100 million in donations.
The Dangerous World Tour was supposed to last until Christmas 1992. However, on November 11, Jackson ended the tour early because he was hospitalized.
In January 1993, Jackson performed at the halftime show at Super Bowl XXVII.
1994-1996
On July 16, 1995, Jackson released his ninth studio album, HIStory: Past, Present and Future, Book I. This album has two discs. The first is a collection of Jackson's greatest hits (his most popular songs). The second contains fifteen songs that Jackson recorded in late 1994 and early 1995. Thirteen of those songs were new at the time, and two of them are cover versions.
HIStory won the Grammy Award for Album of the Year. In August 1995, the album's single "You Are Not Alone" became the first single ever to go straight to No.1 on Billboard's Hot 100 (a list of the 100 most popular songs in the United States). 
The video for Jackson's single "Scream" entered the Guinness Book of World Records for being the most expensive short film ever made. 
In 1996, he started his HIStory World Tour, which ended the following year. Over 4.5 million fans attended a show on the tour - more than any other tour in Jackson's career. Jackson performed 82 concerts in 58 different cities, within 35 countries, on five continents. The tour grossed a total of $165 million. 
In 1997 Jackson released a short film called Ghosts in 1997, which he wrote with Stephen King.
1997-1999
In 1997, Jackson released Blood on the Dance Floor, the best-selling remix album ever made. The album and its first single reached No.1 in the United Kingdom. Blood on the Dance Floor contained five new songs, including the album's first single - also called "Blood on the Dance Floor". 
2000-2003
Jackson won Artist of the 1980s at the American Music Awards in 2000.
On October 30, 2001, Invincible, Jackson's last studio album, was released. The album got good and bad reviews. It was No.1 in 12 countries and sold 13 million copies around the world. But compared to Jackson's earlier albums, it was unsuccessful. The album's first single "You Rock My World" was nominated for the Grammy Award for Best Male Pop Vocal Performance.
In 2002, Jackson won his 22nd American Music Award for Artist of the Century.
On November 18, 2003, Jackson released a collection of his popular songs called Number Ones. The album also includes a new song called "One More Chance", which was released as a single. It reached number one in three countries. The album was released as a DVD too.
2004-2009
In 2006, Sony released twenty of Jackson's popular singles on video called Visionary: The Video Singles.
In March 2009, Jackson told the press that he was going to do a tour called This Is It. He said that he might stop making music after this. Jackson practiced his singing and dancing for the tour in Los Angeles with Kenny Ortega. Jackson died of an overdose of Propofol on June 25, 2009, after having a cardiac arrest, and his personal physician, Conrad Murray, was convicted of involuntary manslaughter.
During an Interview on YouTube during the BBC UK Show featuring "Michael Jackson's This Is It" Michael talked about the future of his career and that he "may" be retiring after his "This Is It" Tour, but he wasn't sure if he would or not. However, due to his death in 2009, the show was cancelled. Some show-goers who paid for tickets wanted refunds but the Jackson Estate did not provide any.
2009-2010
Jackson won Entertainer of the Year at the 2009 Soul Train Awards. That year he also won five American Music Awards.
On October 26, 2009, a two-disc album called Michael Jackson's This Is It was released. The album's only single "This Is It" was nominated for the Grammy Award for Best Male Pop Vocal Performance in 2011. On October 28, 2009, Michael Jackson's This Is It was released. It was a documentary movie. The movie showed recordings of Jackson's rehearsals for his This Is It tour. Jackson died before he could do the tour. It made $72,091,016 in the United States. It has made $261,183,588 around the world. It got good reviews from movie critics. On 26 January 2010 the movie was released on DVD. It sold over a 1.5million copies in the US in the first week it was released. This was more than any other music DVD had sold in its first week.
Jackson won the Grammy Lifetime Achievement Award in 2010. His children, Prince and Paris collected the award for Jackson.
A video game called Michael Jackson: The Experience was released by Ubisoft in November 2010 for the Nintendo DS, PlayStation Portable and Wii.
2011-2012
In April 2011, Mohamed Al-Fayed, who was friends with Jackson when he was alive, showed the public a 7ft 6in statue of Jackson outside Craven Cottage football stadium. A lot of people did not like the statue. In July 2013 Fayed sold his football club to Shahid Khan. In September 2013 Khan chose to have the statue was removed. It was given back to Fayed. Man in the Music: The Creative Life and Work of Michael Jackson, a book written by Joseph Vogel about Jackson's life, was published in 2011.
Jackson was voted as the Greatest Singer of All Time by people who did a poll on NME.com.
In 2011, there was a criminal trial for Jackson's doctor Conrad Murray. Murray was found guilty of involuntary manslaughter of Jackson. He was sentenced to four years in prison. On October 28, 2013, Murray was released from prison. He was interviewed by 60 Minutes. He said that he did not think that Jackson's death was his fault in any way. The journalist Liz Hayes asked Murray if he thought that Jackson was a pedophile. Murray stared at her for 13 seconds and would not give an opinion. He said that he would not answer because he did not want to make anything up.
An extinct species of hermit crab was called Mesoparapylocheles michaeljacksoni after Jackson in January 2012.
Bad 25, a documentary movie about Jackson's album Bad, was released in August 2012.
In 2012 he sold almost 8 albums in the United States. He is thought to have sold 2 albums around the world in 2012. His estate makes $1 a year.
2013-2014
Jackson made more money than any other dead celebrity in 2013.
In May 2013, Wade Robson said that Jackson sexually abused him from the age of 7 to 14. In 2005 he had been a defense witness for Jackson's child molestation trial. In June 2014 there will be a hearing where it is decided whether Robson can sue Jackson's estate over the abuse.
In November 2013, Billboard magazine's issue, 44 did a cover with Michael on it. It said 'Life After Death'. Inside the magazine there was an article about the success of Michael Jackson: The Immortal World Tour.
In January 2014, a judge ruled that Jackson's family could not have another trial against AEG Live. Xscape was released on May 9, 2014.
Voice
Jackson had a unique voice. Between 1971 and 1975, it changed from boy soprano to spinto tenor. 
Jackson had a three and a half octave vocal range. He is the best-known musician to use the 'vocal hiccup'. He first used it in 1973 on It's Too Late to Change the Time on The Jackson 5's G.I.T.: Get It Together album. Jackson also sang 'come on' wrongly on purpose so that it sounded like 'shamone'.
Personal life
Jackson lived a well-publicized personal life, even though he tried to stay private. He was often in celebrity and tabloid magazines. Later in his life, he was in magazines because of his personal life more than for his music.
Marriages and children
In 1994, Jackson married Lisa Marie Presley, the daughter of rock musician Elvis Presley. He divorced her in 1995 and married nurse Debbie Rowe in 1996. 
Three months after Rowe and Jackson's marriage she gave birth to a son, Michael Joseph Jackson Jr. The next year she gave birth to a daughter, Paris-Michael Katherine Jackson. The couple divorced in April 2000. 
Prince Michael II was born on February 21, 2002. Jackson never said who the mother was. He is better known as Blanket. When Blanket was 8 months old, Jackson held him over a balcony with a towel over Blanket's head. At the time, people did not know that he was called Blanket. Jackson made a public apology after people got upset. 
After Jackson died, his mother Katherine was made the guardian of his children. In August 2012, Jackson's nephew TJ was made the children's co-guardian.
Bubbles
In the 1980s, Jackson bought a chimpanzee from a Texas research facility. He named it Bubbles and used it for a pet. 
Bubbles frequently traveled with Jackson, who had a strong attachment to the animal. The chimp, for example, was permitted to use Jackson's personal toilet. As a result, people started to see Jackson as an eccentric. 
The media mocked Jackson and called him "Wacko Jacko," which he hated. Media coverage often focused on Bubbles, rather than on Jackson's music, and many false stories about the animal were told. One such story claimed that Bubbles was not a single ape, but one of several.
 Claims of sexual abuse 
In 1993, he was accused of child molestation, but there was no trial; the case was settled out of court.
In 2003, he was accused a second time of child molestation. In a TV documentary called Living With Michael Jackson, Jackson held hands with a 12-year-old boy called Gavin Arvizo and said that he shared his bed with children. When he was 13, Gavin Arvizo accused Jackson of sexually abusing him. This time Jackson was tried in court, and in 2005 he was found not guilty of fourteen criminal charges.
In May 2013, on the Today show, a dancer called Wade Robson alleged that Jackson sexually abused him for 7 years. Prior to this, Robson had vehemently defended Jackson, including twice under oath.
 Appearance and health 
 Hair 
Over the years, Jackson's face and skin color changed. This attracted a lot of attention.
However, when he was filming a Pepsi commercial in 1984, Jackson got second-degree burns to his scalp. These were extremely painful, and Jackson started taking painkillers. 
In his later years Jackson always wore a hairpiece or wig that blended with his natural hair. His autopsy found that his scalp was tattooed black so that it blended in with his wigs.
 Face 
Jackson's face appeared to go through major changes during his career.
People especially talked about Jackson's nose. Jackson had an immune condition called discoid lupus. According to Dr. Richard Strick, Jackson had an immune condition called discoid lupus that "destroyed part of the skin of his nose". 
Jackson denied having plastic surgery to his face on more than a few occasions. When people pointed out that his face changed, he said that puberty, weight loss and his vegetarian diet were at fault. But the change was so drastic that few people believed him.
Jackson's autopsy found that his lips were tattooed pink. 
 Skin color 
Jackson's skin color varied a lot during the course of his career. It seemed to get lighter over time. People accused Jackson of wanting lighter skin and bleaching his skin to make it that way.
In truth, Jackson had vitiligo, a rare skin condition that creates light spots on the skin. (The skin around these spots keep their normal color.) Large areas of Jackson's body were very pale. He used makeup and medication to try to make his skin color look the same all over his body. This made it look like his skin tone was getting lighter.
Jackson first revealed that he had vitiligo in a 1993 television interview with Oprah Winfrey. Later, his autopsy confirmed that Jackson did have vitiligo, with large sections of white or lightened skin on his body. It also noted that Jackson used a skin-bleaching cream called Benoquin to treat his vitiligo.
 Substance abuse 
Jackson was allegedly addicted to prescription drugs. In fact, he died of a drug overdose. In 2009 his personal physician, Dr. Conrad Murray, gave him intravenous Propofol for his insomnia. The insomnia was actually a side effect of Jackson's addiction to Demerol. While Murray was out of the room, Jackson's heart stopped and he died. 
Jackson had many physicians (including Dr. Murray) who supplied him with medications, including controlled substances like Demerol. 
 Mental health and trauma 
Michael's father, Joe Jackson, abused him physically and emotionally during rehearsals. When he found out his son was self-conscious about his appearance, his father called him "big-nose." 
Some people have suggested that Jackson had body dysmorphic disorder. As a teenager, he had acne. In Living With Michael Jackson, Jackson told Martin Bashir how he went home and cried after a woman called him ugly because of his acne. The disorder is often triggered by appearance-related bullying. 
Some people think that Jackson had anorexia nervosa. In 1984, Jackson weighed 105 pounds. He was 5"9 tall. This would have made his BMI 15.5, which is very underweight. He weighed 112 lbs. when he died. This is in the unhealthy range.
 Physical health 
Jackson may have had a rare genetic disease called Alpha-1 antitrypsin deficiency, according to a biographer called Ian Halperin. Halpern wrote that Jackson's genetic disease had caused him to lose 95% of the vision in his left eye. In fact, Jackson's doctor Conrad Murray said that he thought Jackson was "legally blind" and had phlebitis.
 Controversies 
Aspects of Jackson's personal life, including his changing appearance, personal relationships, and behavior, generated controversy. He was accused of child sexual abuse in 1993, but the case was settled out of court. In 2003, Jackson was charged with child sexual abuse by Gavin Arvizo. In 2005, Jackson was found not guilty of all charges.
 Death 
On June 25, 2009, Jackson was found without a heartbeat and taken by ambulance to the Ronald Reagan UCLA Medical Center. He had been unresponsive since 12:15. He arrived at the hospital with no signs of life. Though he was not pronounced dead when he arrived at the hospital, by 1pm he had already died. His death was announced that day at 2:25pm, and confirmed by the Los Angeles coroner at 4:30pm.
Jackson died just two months before his 51st birthday. The news of his death spread around the world very quickly. People around the world grieved on a scale never seen before. Rumors and news items about Jackson's death broke records for web traffic. Jackson's death gave Google, Twitter, Facebook, and Yahoo the most page views they had ever encountered. This enormous amount of Internet traffic caused a cyberspace traffic jam. 
 Dr. Murray 
Jackson's doctor Conrad Murray, who supplied the Propofol, claimed Jackson took the overdose himself. However, the Coroner ruled the death was a homicide. Murray was charged with involuntary manslaughter and served four years in prison. 
Propofol is used as anesthesia for major surgeries and requires heavy monitoring, including nurses and medical equipment. Conrad Murray admitted to police that he had none of these when he gave Jackson the Propofol. His autopsy discussed how dangerous Murray's actions were. It also noted that Jackson had an increased risk of respiratory failure because he had a lung injury.
 Memorial service 
A two-hour memorial service was held at the Staples Center in downtown Los Angeles on July 7, 2009. It began with Smokey Robinson reading comments by Nelson Mandela, Diana Ross and other close friends of Jackson's who could not attend the memorial. 
Mariah Carey sang "I'll Be There" at the memorial service, followed by a speech given by Queen Latifah. Lionel Richie performed "Jesus is Love". Berry Gordy, Motown founder, spoke next, offering condolences. Kobe Bryant and Magic Johnson also spoke, with Magic describing the event as a "celebration of Jackson's life and works" rather than a funeral. 
Jennifer Hudson sang "Will You Be There" accompanied by a music video. Reverend Al Sharpton then gave a speech about how Jackson kept rising and "never stopped". John Mayer played the guitar as he did in Michael Jackson's song Human Nature. This was followed by Brooke Shields speaking. 
Jermaine Jackson, Jackson's older brother, then performed Smile, Michael's favorite song written by comic drama legend Charlie Chaplin. Next to speak were Martin Luther King III and Bernice King. Congresswoman Sheila Jackson Lee followed them, claiming "people are innocent until proven guilty." (This was a reminder to people who accused Jackson of unproven child molestations). She also said that Jackson's humanitarian efforts should be praised. 
Usher then sang "Gone Too Soon", followed by a montage of old videos of Jackson himself. Shamim sang next, with Kenny Ortega introducing him afterward. Kenny Ortega explained that Michael Jackson saw the Staples Center as his home, which is why the funeral service was held there. Ortega then sang a tribute to Jackson, including "We Are the World" and "Heal the World". 
The service ended with speeches by members of Michael's family, including Jermaine, Marlon and daughter Paris. Paris began to cry and said that "Daddy was the best father anyone could have." She added "I will miss him" before leaving the microphone and turning into Janet Jackson's arms.
Burial
At first, Michael Jackson's custom-made quarter-million dollar golden casket, nicknamed "The Promethean," was not expected to appear at the memorial service. However, due to a change in the family's plans, the casket did appear.
Viewing parties were held all over the world for the broadcast. Movie theaters showed the memorial service in Times Square, the Apollo Theater, Raleigh, and Berlin. The broadcast was replayed a few times the next day. An estimated 1 billion people tuned into the farewell concert.
Over 3,000 police officers were assigned to the event, the largest amount assigned to a single event since the 1984 Summer Olympics. It cost the City of Los Angeles 1.4 million dollars.
Jackson's funeral took place nine weeks after he died, in Glendale, California on September 3, 2009. He was laid to rest at 9:45 pm in the mausoleum, above the ground. Some family members had wanted him to be buried below ground in the mausoleum, while Jermaine Jackson wanted him buried on Neverland ranch. However, Michael's mother Katherine made the final decision.
 Legacy 
Through music videos and live performances, Jackson is known for popularizing dance moves such as the robot, the anti-gravity lean, the side slide, the crotch grab, and the moonwalk. 
He won many awards and broke records. He is the most successful entertainer of all time, according to Guinness World Records. 
Jackson gave to many charitable organizations and pioneered efforts to raise funds for charities in the entertainment industry.
Jackson traveled the world attending events honoring his humanitarianism. In 2000, the Guinness World Records recognized him for supporting 39 charities, more than any other entertainer. 
People continue to buy Jackson's albums and listen to his songs. He is one of the best-selling music artists in history, with worldwide sales approaching 400 million records.
Many of Michael Jackson's songs are still extremely popular. These include:
 "Bad"
 "Beat It"
 "Billie Jean"
 "Black or White"
 "Earth Song"
 "Heal the World"
 "Thriller"
Aftermath
 Recent releases 
Jackson recorded several songs before his death. He had recently released a compilation album called Michael (2010), featuring remixed songs and new songs such as "Hold My Hand" a duet between him and popular singer Akon, and "Monster", a strong song with lots of attitudes and a hint of dislike for the paparazzi. Also "(I Like) The Way You Love Me", "Keep Your Head Up", and "Much Too Soon".
In 2014, he released the second posthumous album, Xscape which includes the songs "Love Never Felt So Good" featuring Justin Timberlake, "Slave to the Rhythm", and "A Place With No Name".
A biopic based on Jackson's life and career was officially announced and will star Jermaine Jackson's son Jaafar Jackson as Michael Jackson. The movie will be released in October 2025.


Islam: Islam (Arabic: إِسْلَام) is an Abrahamic monotheistic religion founded by Muhammad and centered on the Quran and Hadith (the teachings of Muhammad). There are approximately 2 billion Muslims worldwide. A person who believes in Islam is called a Muslim. Islam means submission of one's will to the will of God.
Most teachings and beliefs of Islam are written out in the Quran (the words from God) (also spelled Qur'an), the central holy scripture of Islam. Alongside the Qur'an, Muslims also believe in the previous revelations of God, such as the Tawrat (Torah), the Injeel (Gospel), Muslims believe that the Quran was revealed to Muhammad by the angel Gabriel. The Quran is regarded as the word of God (or Allah), while Muhammad is regarded as the last prophet and messenger of God. Other beliefs and rules about what Muslims should do may come from hadiths. 
Muslims believe that there were many other prophets before Muhammad since the dawn of humanity, beginning with the Prophet Adam and including the Prophet Noah (Nuh), the Prophet Abraham (Ibrahim), the Prophet Moses (Musa), the Prophet David (Dawuud), and the Prophet Jesus (Isa). They believe that all these prophets were given messages by God to their communities, but Satan (referred to as 'Shaytan شيطان' in Arabic) made the past communities deviate from them. Muslims believe that the content of the Quran (written in Arabic) is protected by Allah as mentioned in the Quran and is the final message of God for all of mankind until the Day of Judgement.
Most Muslims belong to one of two groups. The most common is Sunni Islam (75–90% of all Muslims are Sunni Muslims). The second is Shia Islam (10–20% of all Muslims are Shias – also called Shiites). There are also non-denominational Muslims who do not follow any sect and school of thought (madhab); they make up a majority of the Muslims in eight countries (and a plurality in three others): Albania (65%), Kyrgyzstan (64%), Kosovo (58%), Indonesia (56%), Mali (55%), Bosnia and Herzegovina (54%), Uzbekistan (54%), Azerbaijan (45%), Russia (45%), and Nigeria (42%).
With about 1.75 billion followers (24% of the world's population), Islam is the second-largest religion in the world. Islam is also the fastest-growing religion in the world.
 History 
Muslims believe the Qur'an was first revealed to Muhammad by the archangel Gabriel in a cave on the mountain of Hira in Mecca, and then over a period of twenty-three years until his death. The Quran was written in Arabic language.
After Muhammad died, the Arab Muslim leadership was assumed by Abu Bakr. He was followed by Umar, Uthman ibn Affan, Ali, and Mu'awiya I, who established the Umayyad Caliphate. Under these caliphs, Islam became one of the most important religions in the world. Under Umar, more than two thirds of the Eastern Roman Empire was conquered by the Arab Muslims. The Arab Islamic empire reached its largest geographical extent under the Umayyad Caliphate.
Beliefs and practices 
According to the Qur’an, Muslims believe in God, his angels, his books, his messengers, the Last Day, and Fate. In accordance with a Qur’anic verse: “We have created everything with predestination As much is good and bad". And in hadith the Messenger Muhammad when he said that faith is: “to believe in God, his angels, his books, his messengers, and the Last Day, and believe in the destiny of good and bad.” Muslims believe that God is the one God who created the universe with everything in it. The Qur’an was revealed to the Prophet Muhammad through Gabriel. They believe that he is the final messenger of all messengers that are sent before him. The Prophets are human beings, whom God chose to be his messengers. Muslims believe that the prophets are not gods, but merely human beings with some miracles to prove their prophethood. They are the ones who receive divine revelation.
The Quran mentions the names of many prophets, including Adam, Noah, Abraham, Moses, Jesus, and others. According to the Qur’an, all of the prophets were Muslims who preached Islam, but with different laws. Islam is defined in the Qur’an as “the instinct of God upon which people have broken in.” "Therefore set your face to the religion purely, the upright creation upon which He originated people. There is no change in the creation of Allah. This is the valuable religion, although most people do not know} (The Romans -Ar-Rum Surah, versus 30). Muslims also believe that Hanifism is the basis of Abraham's religion. And they see that the difference between the Abrahamic religions is in the Sharia (Law) only and not in the creed and that the Sharia of Islam abrogates what preceded it from the Sharia. this means that Islamic religion consists of Belief and Sharia.
As for belief, it is the set of principles that a Muslim must believe in, and it is fixed and does not differ according to the different prophets. As for Sharia (Law), it is the name for practical rulings that differ according to the different messengers.
 The Five Pillars of Islam 
According to Islamic tradition, there are five basic things that Muslims should do. They are called "The Five Pillars of Islam":
Shahadah: The Testimony (faith in English) is the core of the Muslim belief that there is no God but Allah himself, and that Muhammad is his last messenger.
 Salat: the salat is observed three or (most commonly) five times every day at prescribed times. When Muslims pray, they face the Kaaba, a large cubic structure located at the holy city of Mecca. Salat is namaz in Persian, Urdu and Turkish. Shia Muslims pray the afternoon and evening prayers right after each other. 
 Zakat: Muslims who have money must give 1/40th of the amount which they've had for one year as charity to help people who do not have money or need help.
 Sawm (Also spelled as Siyam or Sawm): Fasting during Ramadan, the ninth month of the Islamic year. Muslims do not eat or drink from sunrise till sunset for one lunar month. After Ramadan, there is a holiday called Eid al-Fitr (which means "festival of end-fast" in English). On Eid al-Fitr, Muslims usually go to the mosque in the morning after sunrise for a special Salaah.
 Hajj (Pilgrimage in English): During the month of Zulhejja, the 12th month of the Islamic Calendar is the pilgrimage season where many Muslims go to Mecca, the holiest city of Islam. However, if a Muslim is financially unable to perform the Hajj, it is not necessary for them to do so. Those who possess great financial capacity were the most obligated to perform the Hajj.
Note: The Five Pillars of Islam is a term in the view of Sunni Islam that gathered out of the hadith. There is another term Usool ul-Din (Religion Principles in English) in Shia Islam. That contains five beliefs : Tawheed, Adl, Nabuwwah, Imamah, Maad.
 Quran 
In Islamic belief, the Quran is the holy book of Islam and contains what Muslims claim Allah (God) conveyed to the Prophet Muhammad through the archangel Jibraeel (Gabriel), who had been tasked since the times of Adam to convey the words of God as guidance to mankind. The Quran is the central point of reference and is a link which connects humanity with God.
The Qur'an contains many passages and chapters which cover the entire aspect of humanity, down to the most minute detail. From the creation and conception of human children, to the details of the Earth, and beyond. In the aspect of human life, it contains stories and tales of old civilizations, past prophets, and their life chronicles. The Quran contains the Sharia law or hudud, and emphasizes the equal rights of man and women alike, with mothers given special status, where it is sinful to even glare at them.
The Qur'an has a total of 30 Juzuks. In each Juz, there are many Surahs or verses, with 114 Surahatun which begin with Surah al-Fatiha (The Beginning) and ended with Surah an-Naas (Humanity). A Hafiz is a Muslim who has memorised the Quran and can accurately say every word in the Quran without flipping a single page and apply them to daily life.
Other important teachings in Islam are previous revelations of God, such as the Tawrat (Torah), the Zabur (Psalms), the Injeel (Gospel), the Scrolls of Abraham, and the Scrolls of Moses, as well as the Sunnah (which tell about Muhammad's life) and the Hadith (which are collections of dialogues of conversation that Muslims believe Muhammad said). 
The Qur'an is considered in Islam as a manual for all of humanity and its teachings are to be implemented and shared by its readers.
Place of worship / Quran readings
Muslims pray in a place of worship called the mosque. A mosque is called a masjid in Arabic. Most mosques were mostly seen having at least a single dome, and some have one or more towers called Minarat, where the Muezzin gives the Adhan, the Call for Muslim Prayer which is 13 or 15 sentences. But many mosques were built without either domes or towers.
Muslims take their shoes off before entering the masjid to pray. Prayer is one of the most important things that a Muslim does.
 Prayer 
The Muslim is called to prayer or salah 5 times a day. This call to prayer is called Adhan. The muezzin, a man chosen to make the call to prayer, uses a loudspeaker, which carries his voice to the people nearby. The call to prayer is often done out loud, in public, in Muslim countries. Being called to solah is a normal part of daily life for most people in Muslim countries.
Muslims pray on a mat, which is called a prayer mat or prayer rug in English. Common Arabic names for the prayer mat include sajjāda and namaz.
When it is time to pray, Muslims made Wudu, then face the direction of Qibla - the direction they are supposed to pray in, towards the Kabah. They then roll out their prayer mat, and perform their prayers to God.
Peace be upon him
According to Islamic teachings, Muslims must say "صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّمَ" shortened as "ﷺ" whenever they hear or say the Prophet's ﷺ name or ﷺ being a common noun.
Islam in the world
In 2009, a study was done in 193+1+=(195)+37 countries and territories. This study found that 23% of the global population or 1.57 billion people are Muslims. Of those, between 75% and 90% are Sunni and between ten and twenty five percent are Shi'a. A small part belong to other Islamic sects. In about fifty countries, more than half of the people are Muslim. Arabs account for around twenty percent of all Muslims worldwide. Islam has three holy sites:Jerusalem, Mecca and Medina.
Most Muslims live in Asia and Africa. Around 62% of the world's Muslims live in Asia, with over 683 million followers in Indonesia, Pakistan, India, and Bangladesh.
In the Middle East: The non-Arab countries such as: Turkey, and Iran are the largest Muslim-majority countries. In Africa: Egypt and Nigeria have the biggest Muslim communities.
Most estimates indicate that the People's Republic of China has about 20 to 30 million Muslims (1.5% to 2% of the population). However, data provided by the San Diego State University's International Population Center to U.S. News & World Report suggests that China has 65.3 million Muslims. Islam is the second largest religion after Christianity in many European countries,
and is slowly catching up to that status in the Americas.
European Islam is the term used for Muslims from the Balkans, former Yugoslavia and Crimea, it including People like Xoraxane Roma, Albanians, Bosniaks, Pomak, Gorani, Torbesh, Turks from Bulgaria, North Cyprus, Greece, Romania, North Macedonia like the Yörüks and East Thrace, the European side in Turkey like the Amuca tribe and Crimean Tatars, the majority belong to the Bektashi Sufism Dervish Tarika.
 Different denominations 
Like with other religions, over time different movements have developed in Islam. These movements are based on different interpretations of the scriptures. The following sections list the most common movements.
 Non-denominational Muslims are Muslims who do not follow any branch and simply call themselves Muslim.
 The Muwahidin or Muwahid Muslims are a Muslim restoration movement that accepts mainstream Islam, but prefer to orient themselves towards a primacy of God's commands on issues pertaining to sharia law. Muwahidists believe that modern Islam has been mixed with many cultural traditions and they want to change that.
 The Shi'ites believe that just as only God can appoint a prophet, he can appoint a second leader after the prophet. Shi'a Muslims believe that God chose Ali as the leader after Muhammad. About 10-20% of Muslims are Shi'a which means that there are about 120 million world wide. Shi'a Muslims form the majority of Muslims in Iran, Azerbaijan, Bahrain, Iraq, and Lebanon. The largest adhab in Yemen is Zaydi Shia. Shias commonly gather for Day of Ashura in Karbala. They accept four hadiths. 
 Sunnism considers Abu Bakr to be the successor of Muhammad. Sunnis make up roughly 75% of Muslims. Sunnis believe that leaders of Islam should be chosen by the people of the Muslim world. After Abu Bakr died, Omar took his place, then Uthman, and then Ali. All of them were companions of Muhammad and lived in Medina. Sunni beliefs are typically based on the Qur'an and the Kutub al-Sittah (six hadiths). Sunnis are sometimes called Bukharists.
 The Sufi are a branch Sunnism that focuses more on the spiritual and mystic elements of Islam. Sufis usually conclude their prayers with dhikr recitations.
 Ahmadiyyas are Muslims who follow Mirza Ghulam Ahmed whom they consider to be the mahdi. They are divided into two subgroups; the Ahmadiyya Muslim Community and the Lahore Ahmadiyya Movement. However, they are not recognised as Muslims by most of the Muslim community.
 The Quraniyoon accept the "Quran alone" as generally reject the authority of the hadiths. Such Muslims, also known as Quranists and Ahle Quran, believe that the Quran is the only source of guidance. They say the hadiths are not endorsed by the Quran, and some call them an innovative bid'ah.
 Ibadis are Muslims who originated from the Kharijites. Ibadis today have reformed beliefs from original Kharijites.


Computer science: Computer science deals with the theoretical foundations of computation and practical techniques for their application.
Computer science is the science of information. Computer scientists study different ways of reading, using, and encoding information.
There are many different areas within computer science. In some areas, scientists only work with ideas "on paper". In other areas they use those ideas to make things like computers and computer programs.
A person who works in computer science will often need to understand logic and mathematics.
 Common tasks for a computer scientist 
 Asking questions 
This is so people can find new and easier ways to do things, and the way to approach problems with this information.
While computers can do some things easily (like simple math, or sorting out a list of names from A-to-Z), computers cannot answer questions when there is not enough information, or when there is no real answer. Also, computers may take too much time to finish long tasks. For example, it may take too long to find the shortest way through all of the towns in the USA - so instead a computer will try to make a close guess. A computer will answer these simpler questions much faster.
 Answering the question 
Algorithms are a specific set of instructions or steps on how to complete a task. For example, a computer scientist wants to sort playing cards. There are many ways to sort them - by suits (diamonds, clubs, hearts, and spades) or by numbers (2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen, King, and Ace). By deciding on a set of steps to sort the cards, the scientist has created an algorithm. The scientist then needs to test whether this algorithm works. This shows how well and how fast the algorithm sorts cards.
A simple but slow algorithm is: pick up two cards and check whether they are sorted correctly. If they are not, reverse them. Then do it again with another two, and repeat them all until they are all sorted. This is called a bubble sort. This method will work, but it will take a very long time.
A better algorithm is: find the first card with the smallest suit and smallest number (2 of diamonds), and place it at the start. After this, look for the second card, and so on. This algorithm is much faster, and does not need much space. This algorithm is called a "selection sort".
Ada Lovelace wrote the first computer algorithm in 1843, for a computer that was never finished. Computers began during World War II. Computer science separated from the other sciences during the 1960s and 1970s. Now, computer science has its own methods, and has its own technical terms. It is related to electrical engineering, mathematics, and language science.
Computer science looks at the theoretical parts of computers. Computer engineering looks at the physical parts of computers (hardware). Software engineering looks at the use of computer programs and how to make them.
 Parts of computer science 
 Central math 
 Boolean algebra (when something can only be true or false)
 Computer numbering formats (how computers count)
 Discrete mathematics (math with numbers a person can count)
 Symbolic logic (clear ways of talking about math)
Order of operations (which math operations are performed first)
 How an ideal computer works 
 Algorithmic information theory (how easily can a computer answer a question?)
 Complexity theory (how much time and memory does a computer need to answer a question?)
 Computability theory (can a computer do something?)
 Information theory (math that looks at data and how to process data)
 Theory of computation (how to answer questions on a computer using algorithms)
 Graph theory (math that looks for directions from one point to another)
 Type theory (what kinds of data should computers work with?)
 Denotational semantics (math for computer languages)
 Algorithms (looks at how to answer a question)
 Compilers (turning words into computer programs)
 Lexical analysis (how to turn words into data)
 Microprogramming (how to control the most important part of a computer)
 Operating systems (big computer programs, e.g. Linux, Microsoft Windows, Mac OS) to control the computer hardware and software.
 Cryptography (hiding data)
 Parallel computing (many instructions are carried out simultaneously)
 Theoretical computer science (how information can be processed)
 Computer science at work 
 Artificial intelligence (making computers learn and talk, similar to people)
 Computer architecture (building a computer)
 Computer graphics (making pictures with computers)
 Computer networks (joining computers to other computers)
 Computer program (how to tell a computer to do something)
 Computer programming (writing, or making, computer programs)
 Computer security (making computers and their data safe)
 Databases (a way to sort and keep data)
 Data structure (how to build or group data)
 Distributed computing (using more than one computer to solve a difficult problem)
 Information retrieval (getting data back from a computer)
 Programming languages (languages that a programmer uses to make computer programs)
 Program specification (what a program is supposed to do)
 Program verification (making sure a computer program does what it should do, see debugging)
 Robots (using computers to control machines)
 Software engineering (how programmers write programs)
 Blockchain (use blockchain technology for security, and privacy)
 What computer science does 
 Benchmark (testing a computer's power or speed)
 Computer vision (how computers can see and understand images)
 Collision detection (how computers help robots move without hitting something)
 Data compression (making data smaller)
 Data structures (how computers group and sort data)
 Data acquisition (putting data into computers)
 Design patterns (answers to common software engineering problems)
 Digital signal processing (cleaning and "looking" at data)
 File formats (how a file is arranged)
 Human-computer interaction (how humans use computers)
 Information security (keeping data safe from other people)
 Internet (a large network that joins almost all computers)
 Web applications (computer programs on the Internet)
 Optimization (making computer programs work better)
 Software metrics (ways to measure computer programs, such as counting lines of code or number of operations)
 VLSI design (the making of a very large and complex computer system)


Sociobiology: Sociobiology is a field of scientific study which is based on the assumption that social behaviour has resulted from evolution. It attempts to explain and examine social behaviour in that way.
A branch of ethology and sociology, sociobiology draws from anthropology, evolution, zoology, archaeology, population genetics, and other disciplines. As a study of human societies, sociobiology is allied to Darwinian anthropology, ethology and evolutionary psychology.
Ethology investigates collective animal behaviour, such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that selection pressure led to the genetic evolution of advantageous social behaviour. In other words, a typical behaviour pattern is inherited because it has raised the inclusive fitness of individuals as compared to other behaviours. This is mainstream biology. Its extension into human social behaviour is for ethologists absolutely normal, but for others it may be controversial.
While the term "sociobiology" can be traced to the 1940s, the concept did not get recognition until 1975 with the publication of E.O. Wilson's book, Sociobiology.
Sociobiology is based upon two fundamental premises:
 Certain behavioural traits are inherited,
 Inherited behavioural traits have been honed by natural selection.
 Therefore, these traits were probably adaptive in the species` original environment.
 Humans are animals
 Therefore, their behaviours have been modified by natural selection
 Therefore, the root of human behaviour is inherited, and our ability to change it by social means has limits. Humans are not blank slates.
It is this last point which is most controversial.
 Criticism 
Wilson's book had almost 700 pages, which were almost entirely devoted to social behaviour in animals. His ideas on the evolution of human behaviour was in a short section of 30 pages at the end of the book. Yet because of this section, the (apparently) new field of sociobiology became the subject of heated controversy. The criticism was driven by political events of the day.
"The mid-1970s were years of intense political activity on campuses, much of it initiated by left-wing professors and their students who opposed the war in Vietnam. At Harvard University [Wilson's employer] the war... came under fire from a number of scholars of the Marxist or semi-Marxist persuasion... Marxist philosophy is founded on the premise of the perfectability of human institutions through ideological prescription. Therefore, persons with Marxist views were particularly unreceptive to the notion that an evolved 'human nature' exists".
Criticism by Richard Lewontin and Stephen Jay Gould, and the Sociobiology Study Group hinted that there was some relationship between these ideas and some of the worst events in history. The main concern of the critics seemed to be the idea that sociobiology provided aid and comfort for those who would maintain social injustice and inequality.p545
Actually, there was no political content in Wilson's last chapter, and Wilson himself was and is a liberal thinker. In the 25th anniversary edition of his book Wilson gives his own account of the controversy.
To avoid some of the controversy, though their ideas are rather similar to Wilson's, some psychologists and anthropologists founded the related field of evolutionary psychology. This shares with sociobiology a belief in the evolutionary origin of behaviour patterns. However, it is more aimed at human behaviour, where sociobiology arose out of experiments on animal behaviour (ethology).
 A human case study 
Why do men have standards of beauty which they apply to women? This is a question to which a typical femininist sociologist would reply: it is culturally determined, a belief system which serves to keep males dominant over females.
To this, John Alcock asks: "What are the actual data? Are the standards of beauty in Western culture arbitrary?" The standards of beauty are consistent with youth and good health. Young, healthy women are more likely to become pregnant and give birth successfully than older or unhealthy women. Alcock asks:
"How likely is it that millions of years of natural selection on humans... would produce a male psyche... indifferent to the cues associated with fertile women? The answer is obvious".p137
Alcock gives the evidence that the signs of youth and beauty are consistent with high reproductive value.p138
 An avian case study 
In some ways, it is easier to study the behaviour of other animals because our own experiences and prejudices are not involved. And we can do experiments on them which might not be possible with humans.
Songbird species almost always have a song which is characteristic of the species. In most cases the details of the song are not inherited. Instead, they inherit an ability to learn at a certain age. If a young male White-crowned Sparrow (Zonotrichia leucophrys) is raised in isolation from the sound of other members of the species, it cannot sing their song. Eventually, it produces a song which is only vaguely like the proper song. But if the experimenter plays a tape of the adult male song, the young will later produce the complete and perfect song when they get to the right age. However, if the young bird is made deaf, it cannot learn the song. From this we learn
 that the capacity to learn is inherited rather than the song itself
 that hearing the adult song triggers the learning process
 that the young bird has to compare the sound it makes to the model song
 a young bird offered two or more songs on tape always learns the one characteristic of its own species.
 but if the young male is only allowed to meet a mature male of another species, it does learn the "alien" song.
This allows us to be sure that the song, as such, is not inherited, but there is inherited a strong learning bias, which makes sense. In order to live and reproduce successfully, it pays for a male to attract a female of the same species, and defend its territory against other males of its species. The right song does both these jobs.p163/5
 Sociobiology today 
In recent years the supporters of sociobiology have claimed to be "winning". They feel its basic ideas are quite sound. We are not blank slates, and our human nature is as much a product of evolution as the rest of us. Even our widespread love of pet animals may be explained by their improving our survival in a prehistoric past.p35/9
 Books


Cancer: October 2014
Cancer is a type of disease where cells grow out of control, divide and invade other tissues. In a person without cancer, cell division is under control. In most tissues, healthy cells divide in a controlled way and copy themselves to create new healthy cells. With cancer, this normal cell division goes out of control. Cells change their nature because mutations have occurred in their genes. All the daughter cells of cancer cells are also cancerous. Such cells are responsible for growing more cancer cells in the body.
If the abnormal cells do not invade other tissues or organs, but just divide and swell up their original tissue, this is not called "cancer". It is called a tumour (when there are multiple they are tumours). Tumours are usually not a threat to life because they can be cut out. However, some tumours occur in places where they cannot be cut out, and they can be fatal. Some brain tumours are of this type.
The symptoms of cancer are caused by the cancerous cells invading other tissues. This is called metastasis. Metastasis is when cancer cells move through the bloodstream or lymphatic system. When this happens, a person's cancer can be spread to other places in the body. Eventually those other tissues cannot work as well, and the whole body begins to get worse, and may die.
Cancer can affect anybody at any age. Most types of cancer are more likely to affect people as they get older. This is because as a person's DNA gets older, their DNA may become damaged, or damage that happened in the past may get worse. One type of cancer that is more common in young men, rather than older people, is testicular cancer (cancer of the testicles).
Cancer is one of the biggest and most researched causes of death in developed countries. Studying cancer and its treatment is called oncology.
 Causes 
Cancer is one of the most common causes of death around the world. It causes about 16% (or one out of every six) of all deaths worldwide, according to the World Health Organization.
Different types of cancer have different causes. Some things are known to cause cancer in a specific body part; other things are known to be able to cause many different types of cancer. For example, using tobacco (smoked or smokeless) can cause many types of cancers, such as lung, mouth, tongue, and throat cancers. 
Other things that are known to be able to cause cancer, or make a person more likely to get cancer, include: radiation including sunlight and X-rays in large or many doses, and exposure to radiation (for example in a nuclear power plant), chemicals and materials used in building and manufacturing (for example, asbestos and benzene), high-fat or low-fiber diets, air and water pollution, eating very little fruits and vegetables, obesity, and other unhealthy diets, alcohol, not enough physical activity, and certain chemicals commonly used at home. Some cancers can also be caused by viruses. Many people who are exposed to these things do not get cancer.
 Kinds 
There are many different kinds of cancers. The most common cancers in the world are: breast cancer, lung cancer, colorectal cancer, prostate cancer and stomach cancer.
 Treatment of cancer 
There is no sure cure for cancer. It can only be cured if all of the cancerous cells are cut out or killed in place. This means that the earlier the cancer is treated, the better the chances are for a cure (because the cancer cells may not have had enough time to copy themselves and spread so much that the person cannot be cured).
There are a few different types of treatments that may kill cancer cells. These treatments are:
 Radiotherapy (radiation therapy), which uses radiation to kill cancer cells
 Chemotherapy, which uses strong medications to kill cancer cells
 Surgery to take out part or all of a tumour. After surgery, many patients may need radiotherapy or chemotherapy to keep the tumour from growing again.
 Immunotherapy works by "inducing, enhancing, or suppressing an immune response".
 Treating cancer is complicated 
There are a few reasons why treating cancer is complicated. For example:
 Most things that kill cancer cells also kill normal, healthy cells. This can cause many side effects, like hair loss and vomiting.
 The body's immune system usually will not attack cancer cells, even though they could easily kill the body. This is because the cancer has actually become a part of the body by invading cells and tissues. So the immune system sees the cancer as part of the body it is trying to protect, not as a threat to be attacked.
 There are many different types of cancer, and each has its own symptoms and causes. Even with the same type of cancer, different people may have different symptoms, and may react to treatments differently; their cancer also may grow or spread at different speeds. Treatment has to be a good fit to both the type of cancer and the individual patient who has the cancer.
Many people in countries around the world study cancer and work on finding treatments. There has been some good progress in finding treatments, and many kinds of cancers are treated with success. Along with looking for different medical treatments to treat cancer, some studies also look for things that people with cancer can do themselves to try to make themselves healthier. For example, one study showed that if a person with lymphedema (a swelling of the arm linked to breast cancer) lifts weights, he may be able to fight his cancer better than somebody who does not lift weights.
 History 
Cancer has been around for many thousands of years. Today, a lot of the medical terms used to describe cancer come from ancient Greek and Latin. For example, the Latinized Greek word carcinoma is used to describe a malignant tumour - a tumour made up of cancer cells. The Greeks also used the word "karkinos", which would be translated by Aulus Cornelius Celsus into the Latin word cancer. The prefix 'carcino' is still used in medical words like carcinoma and carcinogenic. A famous Greek doctor, Galen, helped create another word that is very important to medicine today by using the word "onkos" to describe all tumours. This is where the word oncology, the branch of medicine that deals with cancer, comes from.
 Ancient history 
Hippocrates (a very famous ancient doctor who is often called the father of modern medicine) named many kinds of cancer. He called benign tumours (tumours that are not made up of cancer cells) oncos. In Greek, onkos means 'swelling'. He called malignant tumours karkinos. This means crab or crayfish in Greek. He used this term because he thought that if a solid malignant tumour was cut into, its veins looked like a crab: "the veins stretched on all sides as the animal the crab has its feet, whence it derives (gets) its name". Hippocrates later added -oma (Greek for 'swelling') after the word 'carcinos'. This is how the word carcinoma came about.
Because the ancient Greeks did not believe in opening up dead bodies to study them, Hippocrates was only able to describe and make drawings of tumours he saw from the outside of the body. He drew tumours that had been on the skin, nose, and breasts.
Hippocrates and other doctors at that time treated people based on the humor theory. This theory said that there were four types of fluid in the body (black, yellow bile, blood, and phlegm). Doctors tried to figure out whether these four "humors" (or body fluids) were in balance. They would then use treatments like blood-letting (cutting the patient and letting him bleed so that he would lose blood); laxatives (giving the patient foods or herbs to make him go to the bathroom), and/or changing the patient's diet. The doctors thought that these treatments would work to get the patient's four humors back into the right balance. The humor theory treatment was popular until the 19th century (the 1800s), when cells were discovered. By this time, people had realized that cancer can happen anywhere in the body.
 Early surgery 
The oldest known document that talks about cancer was discovered in Egypt and is thought to be from about 1600 B.C. The document talks about using surgery to treat eight cases of ulcers of the breast. These were treated by cauterization - by burning them - using a tool called "the fire drill". The document also says about cancer, "There is no treatment".
Another very early type of surgery used to treat cancer was written about in the 1020s. In The Canon of Medicine, Avicenna (Ibn Sina) said that treatment should involve cutting out all diseased tissue. This included the use of amputation (removing a part of the body completely) or removing veins that ran in the direction of the tumour. Avicenna also suggested that the area that had been treated should be cauterized (or burned) if needed.
 The 16th and 17th centuries 
In the 16th and 17th centuries (the 1500s and 1600s), doctors started to be allowed to dissect bodies (or cut them open after death) in order to figure out the cause of death. Around this time, there were many different ideas about what caused cancer. The German professor Wilhelm Fabry believed that breast cancer was caused by a clot of milk in the part of a woman's breast that produces milk. The Dutch professor Francois de la Boe Sylvius believed that all disease was caused by chemical processes. He thought that cancer, in particular, was caused by acidic lymph. Nicolaes Tulp, who lived at the same time as Sylvius, believed that cancer was a poison that slowly spreads and was contagious.
A British surgeon named Percivall Pott was the first person to figure out one of the real causes of cancer. In 1775, he discovered that cancer of the scrotum was a common disease among chimney sweeps (people who cleaned out chimneys). Other doctors started studying this topic and coming up with other ideas about what causes cancer. Doctors then started working together and coming up with better ideas.
 The 18th century 
In the 18th century (the 1700s), many people started to use the microscope, and this made a big difference in helping doctors and scientists understand more about cancer. Using the microscope, scientists were able to see that the 'cancer poison' spread from one tumour through the lymph nodes to other sites ("metastasis"). This was first made clear by the English surgeon Campbell De Morgan, between 1871 and 1874.
Before the 19th century (the 1800s), using surgery to treat cancer usually had bad results. Doctors did not understand how important hygiene (or keeping things clean) is for preventing disease, especially after surgery. Because things were not kept clean during or after surgery, patients often got infections and died. For example, one well-known Scottish surgeon, Alexander Monro, kept records and found that 58 patients out of every 60 who had surgery for breast tumours died within the next two years.
 The 19th century 
In the 19th century, surgical hygiene got better because of asepsis. Doctors realized that dirtiness and germs cause infections, so they started to keep things cleaner and do things to kill germs in order to prevent their patients from getting infections. It became more common for people to survive after having surgery. Surgical removal of the tumour (taking the tumour out of the body by doing surgery) became the first-choice treatment for cancer. For this kind of treatment to work, the surgeon doing the operation had to be very good at removing tumours. (This meant that even if people had the same kind of cancer, they could get very different results, with some getting good treatment that worked and others getting treatment that did not work, because of differences in how good different surgeons were.)
In the late 1800s, doctors and scientists started to realize that the body is made up of many kinds of tissues, which in turn are made up of millions of cells. The discovery started the age of cellular pathology (studying cells to learn about diseases and figure out what is wrong with the body).
 Discovery of radiation 
In the 1890s, French scientists discovered radioactive decay. Radiation therapy became the first cancer treatment that worked and did not involve surgery. It required a new multi-disciplinary approach to cancer treatment (people doing different jobs were working together to treat patients). The surgeon was no longer working by himself - he worked together with hospital radiologists (people who gave and read X-rays) to help patients. This team approach meant changes in how they worked. The different people on the team had to communicate with each other and work together, which they were not used to doing. It also meant that treatment had to be done in a hospital rather than at the patient's home. Because of this, patients' information had to be put together into files kept at the hospital (called "medical records"). Because this information was now being kept and written down, scientists were able to do the first statistical patient studies using numbers to study questions like how many people who have a certain type of cancer or get a certain treatment survive.
 The 20th century 
Another important step forward in understanding cancer happened in 1926, when Janet Lane-Claypon published a paper on cancer epidemiology. (Epidemiology is a field of study which looks at how common a disease is, what patterns the disease takes in different kinds of people, and what this means for understanding and treating the disease.) This historic paper was a comparative study, which tries to find out what causes a disease by looking at a group of people who have the disease and figuring out how they are different from another group that does not have the disease. Lane-Clayton's study looked at 1000 people who all had the same background and lifestyle (or way of living): 500 people with breast cancer and 500 control patients (people without breast cancer). These people were the same in many ways, but some got breast cancer and some did not. To figure out what might be causing certain people to get breast cancer, the study looked at what was different about these people when they were compared to (or looked at alongside) the people who did not get cancer.
Lane-Clayton's study was published by the British Ministry of Health. Her work on cancer epidemiology was continued by Richard Doll and Austin Bradford Hill. They used the same ways of studying cancer as Lane-Clayton, but they looked at a different kind of cancer: lung cancer. In 1956, they published their results in a paper called "Lung Cancer and Other Causes of Death In Relation to Smoking. A Second Report on the Mortality of British Doctors" (also called the British doctors study). Later, Richard Doll left the London Medical Research Center (MRC), and started the Oxford unit for Cancer epidemiology in 1968. By using computers, this unit was able to do something new and very important: it brought together large amounts of cancer data (pieces of information about cancer). This way of studying cancer is very important to cancer epidemiology today, and it has also been very important in shaping what we now know about cancer and what the rules and laws about the disease and public health are today. Over the past 50 years, many different people have done a lot of work to collect data from different doctors, hospitals, areas, states, and even countries. This data is used to study whether different kinds of cancer are more or less common in different areas, environments (for example, in big cities compared to the countryside), or cultures. This helps people who study cancer to figure out what makes people more or less likely to get different kinds of cancer.
 Effects of World War II 
Before World War II, doctors and hospitals were getting better at collecting (or getting and keeping) data about their patients who had cancer, but it was rare for this data to be shared with other doctors or hospitals. This changed after WWII, when medical research centers found out that different countries had very different number of cases of cancer. Because of this, many countries created national public health organizations (which studied public health issues in an entire country). These national public health organizations began to bring together health data from many different doctors and hospitals. This helped them figure out some of the reasons why cancer was so much more common in certain places. For example, in Japan, people studying cancer found out that people who had survived the atomic bombings of Hiroshima and Nagasaki had bone marrow that was completely destroyed. This helped them realize that diseased bone marrow could also be destroyed with radiation, which was a very important step in figuring out that leukemia (a blood cancer) can be treated with bone marrow transplants.
Since World War II, scientists have kept finding better cancer treatments. However, there are some things that still need to get better. For example, while there are good treatments for many kinds of cancer, there are still no treatments for certain kinds of cancer, or for some cancers once they progress (or get worse) to a certain stage of the disease. Also, the cancer treatments that do exist are not all standardized (there is not one agreed-upon way of giving every treatment which is used each time the treatment is given). Cancer treatments are also not available everywhere in the world. People need to keep studying cancer epidemiology and forming international partnerships (where different countries work together) to find cures and make cancer treatments available everywhere.


Vice President of the United States: a list of vice presidents List of vice presidents of the United States
The vice president of the United States (VPOTUS) is the second highest executive officer of the U.S. federal government after the president of the United States. The vice president ranks first in the presidential line of succession and is also the officer of the legislative branch, president of the Senate and the presiding officer of the Senate.
JD Vance is the 50th and current vice president of the United States, in office since January 20, 2025.
 Constitutional roles and duties 
 President of the United States Senate 
Article I, Section 3, Clause 4, gives the vice president the title President of the Senate, authorizing the vice president to preside over the Senate. The vice president is responsible for maintaining order, allowing members to speak, and explain the Senate's rules and practices. This position also has the authority to cast a tie-breaking vote.
 Presiding over impeachment trials 
As the president of the Senate, the vice president may preside over impeachment trials, although the Constitution does not specifically require it. When the president is on trial, the constitution requires that the chief justice of the United States must preside. No vice president has ever been impeached.
 Presiding over electoral vote counts 
The Twelfth Amendment allows the vice president, as the president of the Senate, receive the Electoral College votes and opens the sealed votes. The votes are counted during a joint session of Congress every four years on January 6.
 Presidential advisor 
Lyndon B. Johnson, vice president under John F. Kennedy, helped Kennedy navigate complex legislative issues, especially civil rights. Johnson’s influence, with his decades of experience of the Senate, helped push through important legislation, including the Civil Rights Act of 1964.
George H. W. Bush, vice president under Ronald Reagan, worked closely with Reagan, especially in foreign policy, and was often trusted to handle sensitive international relations, like the relationship with China and the Soviet Union.
Al Gore, vice president under Bill Clinton, served as a key advisor to President Clinton on environmental issues, particularly on climate change. Additionally, Gore represented the U.S. abroad, attending international summits and strengthening diplomatic ties, during the Clinton administration's focus on global environmental policy.
Dick Cheney, vice president under George W. Bush, was one of the most powerful vice presidents in U.S. history. He was a close advisor to President Bush, particularly in shaping foreign policy. Cheney played a crucial role in the decision-making process before the Iraq War, where he was seen as a strong influence on Bush's policies, especially regarding national security and defense.
Joe Biden, vice president under Barack Obama, was deeply involved in the administration's policy discussions. He played a key role in foreign affairs and domestic policy, especially during the economic recovery following the 2008 financial crisis. His decades of experience in the Senate made him an important advisor, especially on matters of legislative strategy and foreign relations.
Kamala Harris, vice president under Joe Biden, played a key role in advising Biden, especially in areas like social policy, racial equity, and health care. Her experience as a senator and attorney general has made her a crucial advisor on legal and policy matters. Additionally, she played a central role in helping Biden connect with diverse voters during the 2020 election.
 Diplomatic representation 
The vice president frequently represents the U.S. in diplomatic meetings with foreign leaders. In some cases, they act as a direct representative of the president, displaying U.S. policies, strengthening relationships, and advancing the country’s interests abroad. Joe Biden played a key role in strengthening U.S.-European Union relations during his trips to Europe, especially concerning economic issues and NATO.
Vice presidents often meet with foreign officials to discuss mutual concerns and strengthen diplomatic ties. They may sign agreements, attend ceremonial events, or offer speeches aimed at boosting international relations. Kamala Harris traveled to Southeast Asia in 2021 to reaffirm U.S. commitment to the region, meet with leaders in Vietnam and Singapore to issues like trade, security, and climate change.
On foreign trips, vice presidents are tasked with promoting U.S. interests, whether economic, political, or military. They might attend trade discussions, promote American business and culture, or engage in multilateral talks. Dick Cheney traveled extensively to strengthen U.S. allies in the Middle East and Europe during the Iraq War.
Vice presidents sometimes visit U.S. military personnel deployed overseas to boost and offer support. Lyndon B. Johnson visited U.S. troops during the Cold War to offer support and assess the situation.
One of the vice president’s primary roles on a foreign trip is to build and maintain relationships with foreign leaders. This can include private meetings, public speeches or participating in official ceremonies. Joe Biden traveled to Ukraine in 2011 to strengthen relations and offer support for democratic reforms.
 Congressional liaison 
The vice president is seen as an important liaison between the presidential administration and Congress. Joe Biden worked closely with Congress to pass major laws like the Affordable Care Act and economic recovery plans. Walter Mondale helped push important policies, such as creating the U.S. Department of Education and energy laws by working with Congress.
 National Security Council member 
Since 1949, the vice president has legally been a member of the National Security Council. The vice president is first in line to become president if the sitting president dies resigns, or becomes incapacitated, the vice president must stay well-informed about national security issues.
The vice president often acts as a close advisor to the president. The NSC allows them to participate in discussions and decisions about the country's defense, intelligence, and foreign policy, which are critical to national security. The vice president has the opportunity to influence decisions on military strategy, foreign policy, and other national security concerns. 
 Eligibility and requirements 
Article II, Section 1, Clause 5 of the constitution states for a person to serve as vice president must:
 be a natural-born citizen of the United States.
 be at least thirty-five years old.
 be a permanent resident in the United States for at least fourteen years.
 Election process 
The vice president is elected by the people through the Electoral College to a four-year term, along with the presidential candidate or the incumbent president as their running mate. The presidential candidate or incumbent president must have at least 270 electoral college votes in order to win the election.
 Vice President-elect of the United States 
The vice president-elect of the United States is the candidate who has won the United States presidential election along with the presidential candidate and is awaiting inauguration to become the vice president.
 Inauguration 
The president elect, vice president-elect, or incumbent president and vice president immediately began their four-year team on inauguration day every four years on January 20. The original inauguration date was held on March 4, but was later changed in 1933.
 Presidential line of succession 
The vice president ranks first in the presidential line of succession, if the president dies, resigns, or is impeached. Only eight vice presidents have succeeded the president in resignation or death such as John Tyler, Millard Fillmore, Andrew Johnson, Chester A. Arthur, Theodore Roosevelt, Calvin Coolidge, Harry S. Truman, Lyndon B. Johnson and Gerald Ford. 
The speaker of the House ranks second in the presidential line of succession if the vice president dies, resigns or is impeached from office.
John C. Calhoun and Spiro Agnew are the only U.S. vice presidents to have resigned from office.
 Office of the Vice President 
The Office of the Vice President includes personnel staff who directly support or advise the vice president of the United States. The main office is in the Eisenhower Executive Office Building. There are also offices for the vice president in the West Wing of the White House, United States Capitol, and in the vice president's residence.
 Travel and Transportation 
File:USAF C-32A.jpg Air Force Two – the vice presidential airplane used for carrying the vice president domestically and on foreign trips Vice President Harris disembarks Marine Two - 2024.jpg Marine Two – the vice presidential helicopter used for carrying the vice president Vice President attends Air Force Academy graduation (8440429).jpg Vice Presidential Motorcade – the car used for driving the vice president center packed 160 
 Residence 
Number One Observatory Circle; December 2017.jpg Number One Observatory Circle – the official residence of the vice president center packed 160 
Number One Observatory Circle is the official residence of the vice president and the second family of the United States. It has been the official residence of every U.S. vice president since Nelson Rockefeller in 1974.
 Protection 
The United States Secret Service is in charge of protecting the vice president and the second family at all times. As part of their protection, the vice president, second spouse and immediate family members are given Secret Service codenames. The use of codenames are used due to security and safety reasons.
List of living former vice presidents
There are six current living former vice presidents. 
  center
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 National Veterans Day Observance 2019 (49051656176) (cropped).jpg Dan Quayle 1989–1993 – served under George H. W. Bush
 President Joe Biden presents the Medal of Freedom to Al Gore (cropped).jpg Al Gore 1993–2001 – served under Bill Clinton
 Dick Cheney (5446793522) (cropped).jpg Dick Cheney 2001–2009 – served under George W. Bush
 President Joe Biden 2025.jpg Joe Biden 2009–2017 – served under Barack Obama
 Mike Pence (53299483780) (cropped).jpg Mike Pence 2017–2021 – served under Donald Trump
 Kamala Harris - 53915644463 (cropped).jpg Kamala Harris 2021–2025 – served under Joe Biden


Climate change: climate change now Global warming
Climate change refers to long-term changes in temperature, precipitation, and other atmospheric conditions on Earth. It primarily involves the warming of the planet due to increased concentrations of greenhouse gases, like carbon dioxide and methane, from human activities such as burning fossil fuels, deforestation, and industrial processes. These changes can lead to a variety of impacts, including more extreme weather events, rising sea levels, and disruptions to ecosystems and agriculture. 
When people talk about climate change they are usually talking about the problem of human-caused global warming, which is happening now (see global warming for more details). But the climate of the Earth has changed over not just thousands of years, but tens or hundreds of millions of years. 
The earth's climate changes over time, so it could be hotter or colder at a certain time. For example about 60 million years ago there were a lot of volcanoes, which burnt a lot of underground organic matter (squashed and fossilized dead plants and animals became coal, gas and oil). A large amount of carbon dioxide and methane went up in the air. 
At times in the past, the temperature was much cooler, with the last glaciation ending about ten thousand years ago. Ice Ages are times when the Earth got colder, and more ice froze at the North and South Poles. There have been times when Earth has been covered in ice, and was much colder than today. 
There is no one reason why there are Ice Ages. Changes in the Earth's orbit around the Sun, and the Sun getting brighter or dimmer are events which do happen. Also how much the Earth is tilted compared to the Sun might make a difference. Another source of change is the activities of living things (see Great Oxygenation Event and Huronian glaciation).
 Hot Earth 
Sometimes, before there were people, the Earth's climate was much hotter than it is today. For example about 60 million years ago there were a lot of volcanoes, which burnt a lot of underground organic matter (squashed and fossilized dead plants and animals like coal, gas and oil) so a lot of carbon dioxide and methane went up in the air like nowadays. This made the Earth hot enough for giant tortoises and alligators to live in the Arctic.
 Cold Earth 
 Glaciations 
At times in the past, the temperature was much cooler, with the last glaciation ending about ten thousand years ago.
 Ice Ages 
Ice Ages are long times (much much longer than glaciations) when the Earth got colder, and more ice froze at the North and South Poles. Sometimes even the whole Earth was covered in ice, and was much colder than today. There is no one reason why there are Ice Ages. Changes in the Earth's orbit around the Sun, and the Sun getting brighter or dimmer are events which do happen. Also how much the Earth is tilted compared to the Sun might make a difference. Another source of change is the activities of living things (see Great Oxygenation Event and Huronia glaciation).
 History of climate change studies 
Joseph Fourier in 1824, Claude Pouillet in 1827 and 1838, Eunice Foote (18191888) in 1856, Irish physicist John Tyndall (1820–1893) in 1863 onwards, Svante Arrhenius in 1896, and Guy Stewart Calendar (1898–1964) discovered the importance of carbon dioxide (CO2) in climate change. Foote's work was not appreciated, and not widely known. Tyndall proved there were other greenhouse gases as well. Nils Gustaf Ekholm in 1901 invented the term.
 The Sun 
The Sun gets a little bit hotter and colder every 11 years. This is called the 11-year sunspot cycle. The change is so small that scientists can barely measure how it affects the temperature of the Earth. If the Sun was causing the Earth to warm up, it would warm both the surface and high up in the air. But the air in the upper stratosphere is actually getting colder. Therefore the changes in the Sun are not causing the global warming which is happening now.
According to the United Nations’ Intergovernmental Panel on Climate Change (IPCC), the current scientific consensus is that long and short-term variations in solar activity play only a very small role in Earth’s climate. Warming from increased levels of human-produced greenhouse gases is actually many times stronger than any effects due to recent variations in solar activity.
For more than 40 years, satellites have observed the Sun's energy output, which has gone up or down by less than 0.1 percent during that period. Since 1750, the warming driven by greenhouse gases coming from the human burning of fossil fuels is over 270 times greater than the slight extra warming coming from the Sun itself over that same time .
 Sustainable energy and environment 
Renewable energy or sustainable energy includes any energy source that cannot be exhausted. It can remain viable for a long period of time without running out or lasts forever. Examples are solar, wind, hydropower (water), geothermal, tidal and biomass. 
Sustainable energy choices play a crucial role in mitigating the impact of human activities on the environment. Here's an overview of some key sustainable energy options and their environmental impacts according to research: 
 Solar energy 
Sunlight from the Sun when converted produces solar energy. It is in abundance and freely available. The type of energy obtained is clean and easily renewable. It has low maintenance cost and can generate energy in any climate.
 Wind energy 
Another clean form of energy is wind. This energy is a plentiful source of renewable energy source. However, it is only available sometimes.
Through history, the use of wind power has waxed and waned, from the use of windmills in centuries past to high tech wind turbines on wind farms today.


Leonardo da Vinci: Leonardo Vinci
Leonardo Da Vinci (15 April 1452 – 2 May 1519) was an Italian polymath who lived during the Renaissance. He is famous for his paintings. He was also a scientist, mathematician, engineer, inventor, anatomist, sculptor, architect, botanist, musician, and writer. Leonardo wanted to know everything about nature, and wanted to know how everything worked. He was very good at studying, as well as designing and making all sorts of inventions.
The art historian Helen Gardner said that no one has ever been quite like him because he was interested in so many things that he seems to have had the mind of a giant, and yet what he was like as a person is still a mystery.
Leonardo was born in Vinci, a small town near Florence, Italy. He was trained to be an artist by the sculptor and painter Verrocchio. He spent most of his life working for rich Italian noblemen. In his last years, he lived in an expensive home given to him by the King of France.
Two of his paintings are among the best-known in the world: the Mona Lisa and The Last Supper. He did many drawings. His best-known drawing is Vitruvian Man. Leonardo often thought of new inventions. He kept notebooks with notes and drawings of these ideas. Most of his inventions were never made. Some of his ideas were a helicopter, a tank, a calculator, a parachute, a robot, a telephone, evolution, and solar power.
 Life 
 Childhood, 1452–1466 
Leonardo was born on the 15th of April, 1452, in the Tuscan hill town of Vinci, in the valley of the Arno River. His grandfather, Antonio da Vinci, wrote down the details of the birth. Leonardo's parents were not married. His father was a Notary, Ser Piero da Vinci. His mother, Caterina, was a servant. She may have been a slave from the Middle East, or from China. His father later took custody of Leonardo, and his mother remarried and had 5 more children. Leonardo's full name was "Leonardo di ser Piero da Vinci", which means "Leonardo, the son of Messer (Mister) Piero da Vinci".
Leonardo spent his first five years living in a farmhouse with his mother. After that, he lived in Vinci with his father, his father's new wife Albiera, his grandparents, and uncle Francesco. When Leonardo grew up, he only wrote down two memories from his childhood. He remembered that when he was lying outside in his cradle, a large bird flew from the sky and hovered over him. Its tail feathers brushed his face. Leonardo's other important memory was when he found a cave while exploring in the mountains. He was terrified that some great monster might be hiding there, but he was also very excited and wanted to find out what was inside.
Leonardo started painting major works when he was about 29 or 30 years old. His first major painting was the Adoration of the Magi, and his last major painting was The Virgin and Child with Saint Anne, painted when he was about 66 or 67 years old. Giorgio Vasari wrote about Leonardo's life shortly after his death. He tells many interesting stories about how clever Leonardo was. He says that Leonardo painted a round wooden shield with a picture of snakes spitting fire. Messer Piero took his son's painting to Florence and sold it to an art dealer.
 Verrocchio's workshop, 1466–1476 
In 1466, when Leonardo was fourteen, his father took him to Florence, to be an apprentice to the artist Verrocchio.
Florence was an exciting place for a young person who wanted to be an artist. Many famous artists had lived in Florence, starting with Cimabue and Giotto in the 1200s. Everywhere a person looked, there were famous and beautiful artworks. The huge cathedral had an enormous new dome. The church of St John had doors that gleamed with gold and were said to be the most beautiful doors in the world. Another church had statues all around it by the most famous sculptors, including one by Leonardo's teacher Verrocchio.
If an artist was lucky, they would find a rich patron who would buy lots of their paintings. The richest family in Florence were the Medici. They had built themselves the finest palace in Florence, and liked buying paintings, statues and other beautiful things. They were also interested in the study of literature and philosophy. Many young artists hoped to get work from the Medici and their friends.
Verrocchio had a big workshop that was one of the busiest in Florence. Leonardo was learning to be an artist, so he had to learn drawing, painting, sculpting and model-making. While he was at the workshop, he learned many other useful skills: chemistry, metallurgy, metal working, plaster casting, leather working, mechanics and carpentry.
Leonardo was not the only young painter at Verrocchio's workshop. Many other painters trained there, or often visited. Some of them later became famous: Ghirlandaio, Perugino and Botticelli. These artists were all a few years older than Leonardo.
Giorgio Vasari tells an interesting story from this time in Leonardo's life. Verrocchio was painting a large picture of the Baptism of Christ. He gave Leonardo the job of painting one of the angels holding Jesus' robe on the left side of the picture. Vasari said that Leonardo painted the angel so beautifully that Verrocchio put down his brush and never painted again. When the painting is examined closely, it is possible to see that many other parts of the picture, such as the rocks, the brown stream and the background may have been painted by Leonardo as well. Verrocchio made a bronze statue of David at this time. It is believed that he used Leonardo as his model.
In about 1472, when he was twenty, Leonardo joined the Guild of St Luke, an organization of artists and doctors of medicine. Even after his father set him up in his own workshop, Leonardo still enjoyed working at Verrocchio's workshop. Leonardo's earliest known work is a drawing in pen and ink of the Arno River valley. It has the date 5 August, 1473. It is now in the Uffizi Gallery.
 Working life 1476–1499 
When Vasari writes about Leonardo, he uses words like "noble", "generous", "graceful," and "beautiful". Vasari tells us that as an adult, Leonardo was a tall handsome man. He was so strong that he could bend horseshoes with his bare hands. His voice was so beautiful that it charmed everyone that heard it. Almost everyone wanted to be his friend. He loved animals, was a vegetarian and would buy birds at the market to set free.
Very little is known about Leonardo's life and work between 1472 and 1481. People think he was busy in Florence. In 1478, he had an important commission to paint an altarpiece for the Monks of San Donato a Scopeto. The painting was to be the Adoration of the Magi (The Three Wise Men). The painting was never finished because Leonardo was sent away to Milan.
Leonardo was a very talented musician. In 1482, he made a silver lyre (a musical instrument) in the shape of a horse's head. At that time there was a new ruler in the city of Milan, in the north of Italy. Duke Ludovico il Moro was making other rulers nervous. Lorenzo Medici sent Leonardo to Milan as an ambassador. Lorenzo de' Medici wanted Leonardo to give Ludovico the lyre as a present from him. Leonardo wrote a letter to the Duke of Milan, telling him about all the clever and useful things that he could do, like making war machines. He wrote in the letter that he could "also paint". Leonardo did not know at the time that it was for painting that he would be mostly remembered. Leonardo stayed in Milan and worked for the Duke between 1482 and 1499. Part of his work was to design festivals and carnival processions. In Leonardo's notebooks are drawings of theatre costumes, amazing helmets and scenes that might be for the theatre.
Leonardo, like most other well-known artists of his time, had servants, young students and older assistants in his workshop. One of his young students was a boy whose name was Gian Giacomo Caprotti da Oreno. He was a handsome boy with beautiful long golden curls. He looked perfect as an artist's model for an angel. But he was such a difficult and dishonest boy that Leonardo called him "Salai" or "Salaino" which means "the little devil". Leonardo wrote in his notebook that Salai was very greedy, that he was a liar and that he had stolen things from the house at least five times. Salai stayed in Leonardo's household for thirty years as a pupil and a servant.
 Gran Cavallo 
Leonardo's most important work for Duke Ludovico was to make a huge statue of the previous ruler, Francesco Sforza, on horseback. He started with the horse. After studying horses and drawing designs, he made a huge horse of clay. It was called the "Gran Cavallo". It was going to be cast in bronze, and it was going to be the biggest bronze horse made in more than a thousand years. Unfortunately, the bronze horse was never made. In 1494, Ludovico had the bronze made into cannons because the French army was invading Milan. The huge clay horse was still standing when the French army invaded again in 1499. It was used for target practice and completely destroyed.
 The Virgin of the Rocks 
While Leonardo was working for Duke Ludovico, he had two important painting commissions. One was an oil painting to go in a big altarpiece for the Confraternity of the Immaculate Conception. Leonardo did the painting twice. He left one with the monks in Milan, and took the other painting to France. It is now displayed in the Louvre Museum. Both paintings are called the Virgin of the Rocks. They show a scene of the Virgin Mary and the child Jesus in a rocky mysterious landscape. Mary and Jesus are meeting with John the Baptist. There is a story (which is not in the Bible but is part of Christian tradition) about how the baby John and the baby Jesus met on the road to Egypt. In this scene John is praying and the baby Jesus raises his hand to bless John. The paintings have a strange eerie light with soft deep shadows. In the background is a lake and mountains in the mist. No paintings like this had ever been done before.
 The Last Supper 
Leonardo's other important painting in Milan is even more famous: The Last Supper. The painting shows the last meal shared by Jesus with his disciples, before his capture and death. Leonardo chose to paint the moment when Jesus said "one of you will betray me". Leonardo tells the story of the surprise and upset that this caused to the twelve followers of Jesus. He shows this through the actions and faces of the people in the painting. Some are talking, some have stood up, and some are raising their hands in horror.
The novelist Matteo Bandello saw Leonardo at work. Bandello wrote that on some days he would paint from morning till night without stopping to eat. Then for three or four days he would not paint at all. He would often just stand and look at the painting. Vasari said that the prior of the convent was very annoyed. He asked Ludovico to tell Leonardo to work faster. Vasari said that Leonardo was worried because he did not think that he could paint the face of Jesus well enough. Leonardo told the Duke that he might use the face of the prior as his model for Judas, the traitor.
When it was finished, everyone that saw it said that the painting was a masterpiece. But Leonardo had not used proper fresco for the painting. He had used tempera over gesso, which is not usually used for wall painting. Soon the painting started to grow mold and flake off the wall. In a hundred years it was "completely ruined".
Even though in some places the paint has fallen right off the wall, the painting is so popular that it is printed and copied more that any other religious painting in the world.
 Working life 1499–1513 
In 1499, Ludovico il Moro was overthrown. Leonardo left Milan with his servant Salai and a friend, Luca Pacioli, a mathematician. They went to Venice, where Leonardo worked as a military architect and engineer. Because Venice is a city on many islands, Leonardo tried to think of ways to defend the city from a naval attack.
In 1500, Leonardo went back to Florence, taking his "household" of servants and apprentices with him. The monks from the monastery of The Holy Annunciation gave Leonardo a home and a large workshop. In 2005 when some buildings which were used by the Department of Military Geography were being restored, the restorers discovered that part of the building used to be Leonardo's studio.
 The Virgin and Child with St Anne and John the Baptist 
Leonardo started work on a new painting. He drew a large "cartoon" (a drawing that is a plan for the painting). The cartoon showed the Virgin Mary sitting on the knee of her mother, St Anne. Mary holds the baby Jesus in her arms. Jesus stretches out his hands to his young cousin John the Baptist. Vasari says that everyone was so amazed by the beautiful drawing that "men and women, young and old" came in large groups to see it "as if they were attending a great festival". The drawing is now in the National Gallery, London. Even though it is old, faded, and kept in a dark room, people go to the gallery to sit in front of it every day.
 The Battle of Anghiari 
In 1502 and 1503, Leonardo worked for Cesare Borgia, a powerful noble who was the son of Pope Alexander VI. Leonardo travelled around Italy with Borgia as a military architect and engineer. Late in 1503, Leonardo returned to Florence. He rejoined the Guild of St Luke.
He was given a very important commission. The Signoria (Town Council) of the City of Florence wanted two large frescos painted on the walls of the most important room of the Signoria Palace. Michelangelo was to paint The Battle of Cascina and Leonardo was to paint The Battle of Anghiari. Leonardo began the project by studying and drawing the faces of angry men and fighting horses. These drawings can still be seen in his notebooks. But unfortunately, this was to be another failure for Leonardo. When he painted the picture on the wall, instead of using fresco, he mixed the paints with oil. The paint would not dry. Leonardo lit some fires to dry it, and the painting melted. Peter Paul Rubens drew a copy of the middle part. After a time, the town council covered it up and got somebody else to paint the wall. Michelangelo did not finish his painting either, because the Pope called him to Rome.
 Mona Lisa 
In about 1503 Leonardo began painting the portrait of a woman known as Mona Lisa, the most famous portrait that has ever been painted. He continued working on it for many years. It is a small picture, painted in oil on a wooden panel. It shows the face, upper body and hands of a woman. She is very plainly dressed. For a portrait, a woman would usually put on her best clothes and jewellery. Mona Lisa has a dark dress and a fine black veil over her head. Leonardo often left symbols in his paintings that give clues about the person. The unusual thing about this picture is the smile. The smile is the clue to her name: Mona Lisa Giacondo. Giacondo means "the joking one". (Mona is short for Madonna which means "My Lady".)
The reason why the painting is so famous is that it seems to be full of mystery. Mona Lisa's eyes look out at the viewer. But no-one can guess what she is thinking. Her eyes and her mouth seem to be smiling. This is very unusual in a portrait painting. Most people in portraits look very serious. It is hard to tell what Mona Lisa's exact expression is. When a person wants to read another person's feelings, they look at the corners of their mouth and eyes. But Leonardo has painted soft shadows in the corners of Mona Lisa's mouth and eyes, to disguise her expression. The soft shadows are also found on the sides of her face, her neck and hands. The way that Leonardo uses shadow is called "sfumato" (which is an Italian word for "smoke"). Vasari said that the picture was so beautifully painted that every other artist who looked at it thought that they could never paint so well.
 Working life, 1506–1516 
In 1506, Leonardo went back to Milan with his pupils, and lived in his own house in Porta Orientale. D'Oggione made several copies of the Last Supper. Luini made a copy of the Virgin of the Rocks. Boltraffio (and the others) painted many Madonna and Child pictures which can still be seen in art galleries and churches. One of pupils was a young nobleman called Count Francesco Melzi. Melzi never became a very good painter, but he loved Leonardo and stayed with him until the day he died.
In September 1513 Leonardo went to Rome and lived there until 1516. He lived in the Vatican. The three greatest painters of the High Renaissance, Leonardo, Michelangelo and Raphael were all working in Rome at the same time. Even though their names are often said together as if they were friends, they were not. Leonardo at this time was in his sixties, Michelangelo was middle-aged. He was not friendly to either Leonardo or Raphael. Raphael was a very clever young painter who learnt a lot by looking at the pictures painted by Leonardo and Michelangelo. But neither of them was ever his teacher.
In October 1515, King Francis I of France captured Milan. On December 19, there was a meeting of Francis I and Pope Leo X, in Bologna. Leonardo went to the meeting with Pope Leo. Leonardo made an amazing toy to entertain King Francis. It was a life-sized mechanical lion that could walk. It had doors in its chest which opened, and a bunch of lilies came out. Lilies were the royal symbol of the French Kings.
 Old age, 1516–1519 
In 1516, Francis I invited Leonardo to go to France with him. He gave Leonardo a beautiful house called Clos Lucé (sometimes called "Cloux"). It is near the king's palace, Chateau Amboise. Leonardo spent the last three years of his life at Clos Lucé, with his faithful friend and apprentice, Count Melzi. The king gave Leonardo a pension of 10,000 scudi. One of the last paintings that Leonardo did was a picture of John the Baptist. His model was Salai, with his beautiful long curling hair.
When Leonardo was dying, he asked for a priest to come, so that he could make his confession and receive Holy Communion. Leonardo died at Clos Lucé, on May 2, 1519. King Francis had become a close friend. Vasari says that the King held Leonardo's head in his arms as he died. In his will, he asked that sixty beggars should follow his casket in procession. He was buried in the Chapel of the Chateau Amboise.
Leonardo had never married and had no children of his own. In his will, he left his money, his books and most of his paintings to Count Melzi. Leonardo also remembered his other pupil Salai and his servant Battista di Vilussis, who each received half of Leonardo's vineyards near Milan. Leonardo left to his serving woman a black cloak with a fur edge. Salai was the owner of Leonardo's most famous oil painting, the Mona Lisa. He still owned it a few years later when he died, after fighting in a duel.
King Francis said: "There had never been another man born in the world who knew as much as Leonardo, not so much about painting, sculpture and architecture, as that he was a very great philosopher."
 Drawings 
Leonardo did not paint very many pictures. But he drew hundreds of quick sketches, plans, maps and detailed drawings. This is how he recorded all the interesting things that he saw, studied and thought about. Some of Leonardo's drawings are "studies" for paintings. In these drawings Leonardo planned the things he was going to paint. Some studies are plans for whole paintings. One of these paintings is the large beautiful drawing of the Madonna and Child with St Anne and St John the Baptist that is now in the National Gallery, London. Many of the studies show "details" that Leonardo wanted to get just right. One study shows a very detailed perspective drawing of the ruined buildings in the background of the painting of the Magi. Other studies show hands, faces, drapery, plants, horses and babies. The earliest drawing by Leonardo that has a date on it, is a Landscape of the Arno Valley, 1473, which shows the river, the mountains, Montelupo Castle and the farmlands beyond it in great detail.
 Leonardo's notebooks 
Leonardo studied things throughout his life. He did not go to university to study. He studied by observing things in the world around him, to see how they were made and how they worked. He drew things that he saw and discoveries he made into his notebooks. Many of his notebooks are now in museums. There are about 13,000 pages of notes and drawings in his notebooks, which are mostly scientific studies.
Leonardo's notebooks are hard to read because he wrote backwards in "mirror writing". Some people think that perhaps he was trying to keep his work secret. This is not true. Leonardo wrote (and sometimes drew) with his left hand. In those days pens were made from a quill (a large feather) that was cut with a pen-knife on the end. It is hard for a left-handed person to write with a quill in the ordinary way, but quite easy to write backwards.
It is likely that Leonardo planned to publish the studies in his notebooks. He organized many pages carefully, with one study taking up the front and back of each page. There is a page with drawings and writing about the human heart and a page about the womb and the fetus. One page shows drawings of the muscles of a shoulder and another page shows how an arm works.
The notebooks were not published in Leonardo's lifetime. After he died, they were divided between different people who had known him. They are nearly all in museums or libraries such as Windsor Castle, the Louvre, and the British Library. The Biblioteca Ambrosiana (a library) in Milan has the twelve-volume Codex Atlanticus.
 Studies 
Some of the things that Leonardo studied are: 
 The geology of the Earth, with its mountains, valleys, rivers and rocks.
 The anatomy of the human body with its skeleton, muscles, veins and internal organs. Leonardo was given dead bodies by a hospital. He dissected thirty dead bodies and carefully drew many of the parts. His drawings of bones and muscles were to help other artists to paint the human body properly.
 The anatomy of horses, cows, dogs, and bears.
 The expressions on human faces.
 The flight of birds .
 The weather and its phenomena.
 The way that water flows.
 The botany of plants.
 Light, shadows, mirrors and lenses.
 Perspective and the way to make things look near or far.
 The geometry of solid objects. He drew many careful pictures which were used by the mathematician Luca Pacioli in a book called De Divina Proportione.
 Designs and inventions 
Many of the drawings and notes in Leonardo's notebooks are designs, plans and inventions.
Some of the things that Leonardo designed are: 
 Costumes for parades, carnivals and theatre. These were probably for Duke Federico's court. They include armour, and a ferocious dragon.
 War machines such as an armour-plated tank, an enormous cross bow and a horrible horse-driven leg-chopper. None of these things were ever made in Leonardo's lifetime.
 Dams and canals for rivers.
 A wooden bridge that could be carried flat on wagons and unfolded and put together at the river.
 Flying things with wings that flapped, a helicopter, a parachute and a hang glider. One of Leonardo's servants was injured, trying out the hang glider. The parachute has been made and tested in modern times, and it does work.
 Church (building) and castles. It is possible that the Castle of Locarno, in the south of Switzerland was designed by Leonardo. No other building that he designed was built.
 Leonardo's studies, designs and inventions


Camarão Indians' letters: Camarão Indians' letters (cartas dos índios Camarões) is the name for six letters the Potiguara Indians wrote during 1645. They were written because of the Dutch Invasion of Brazil. They are also known as Tupi letters from Camarão Indians (cartas tupis dos Camarões).SAMPAIO 1906 They are the only known texts written by Brazilian Indians until the Independence of Brazil. The Camarão Indians' letters are also the only record of Old Tupi writing in Colonial Brazil. Today, the letters are in the archives of the Royal Library of the Netherlands; they have been there for almost 400 years.NAVARRO 2005NAVARRO 2013BARBOSA BARROS MONSERRAT 2020
The letters are known since 1885. People tried to translate them, but failed. Eduardo de Almeida Navarro, a philologist , published the first complete translation in October 2022. He also transcribed the letters, and left some comments.NAVARRO 2022
A seventh letter was later found in the National Archive, in the city of Rio de Janeiro.
 Context 
In 1624, the Dutch organized an invasion of the Brazilian Northeast. They did this using the West India Company. They were not successful. They later returned to Europe with some natives. Among them we Antonio Paraupaba and Pedro Poti. Both converted to Calvinism in Europe, where they lived for five years. They also got an education in Dutch.COSTA 2021
Five years later, in 1630, the Dutch again invaded Pernambuco in order to establish a colony in Brazil.NAVARRO 2005 They came with more than seven thousand men and 67 ships. They succeeded, and by 1640 they already dominated a considerable portion of the northeastern coast. — Maranhão, Paraíba, Pernambuco, Rio Grande do Norte and Sergipe.NAVARRO 2005 However, in 1644 the Dutch governor Jean Maurice (Johan Maurits) of Nassau returned to the Netherlands. He had managed to balance the complicated relations between the West India Company and the indebted sugar plantation owners, and to enforce religious freedom.
Because the Dutch always came to collect the debts, the sugarcane farmers wanted to expel the Dutch. When Maurice of Nassau left, religious conflicts started agaiin. In 1645, the Dutch killed faithful Catholics, in Cunhaú, in the town of Canguaretama. In October, another slaughter was recorded, this time in Uruaçu.
In the same year, the Pernambuco Insurrection pt Insurreição Pernambucana began, a movement opposed to Dutch rule and commanded by André Vidal de Negreiros, Henrique Dias, and Antônio Filipe Camarão.NAVARRO 2005
A Tupi-speaking Potiguara, Filipe Camarão was responsible for leading the Christian Indians (like his uncle Jaguarari Simão Soares ptThe versions "Jaguarary", "Jaguari" and "Jaguary" are also found. Among the Portuguese, he was known only as "Simão Soares". and his cousin Diogo Pinheiro Camarão) against the Dutch. Some Indians supported the Dutch side, among them the caciques Pedro Poti, also a cousin of Filipe Camarão, and Antônio Paraupaba.NAVARRO 2005
That is the context in which the letters were written and exchanged among the Portuguara. Those on the side of the Portuguese sent letters to the allies of the Dutch, to persuade them to change sides. The messages were written in Old Tupi because their recipients, Pedro Poti and Antônio Paraupaba,The versions "Paraopaba" and "Paraopeba" are also found. had been literate in Dutch, unlike their senders who were literate in Portuguese. The Old Tupi language was therefore a means of communication between the two sides of the conflict.
 Translation 
 History 
In 1906, the engineer Teodoro Fernandes Sampaio attempted to translate the letters in his article Cartas tupis dos Camarões (Camarão Indians' Tupi letters). He received them from historian José Higino Duarte Pereira pt, who had discovered them in 1885. Sampaio confessed that only with great difficulty could he understand them, and he could not translate them all. He therefore limited himself to only two letters.
Until the 1990s, there are no other documented attempts at translating them. In the 1990s, Aryon Rodrigues, a professor at Unicamp and a linguist went to the Netherlands, to look for them.NAVARRO 2013 He tried to translate them, but was unable to. At the same time, philiogist Eduardo de Almeida Navarro came in cxontact with the letters. He said the were hard to translate, because there were no Tupi dictionaries. In 2013, Eduardo Navarro published published a dictionary. He also devoted himself to the letters, and produced a microfilm version. This versionis at the Hague Library.NAVARRO 2013
Eight years later, in 2021, , Eduardo Navarro announced that he had translated the six letters. This was widely covered by the Brazillian press. The transcription and annotated full translation of the Camarão Indians' letters were published in the periodical Boletim do Museu Paraense Emílio Goeldi in October 2022.NAVARRO 2022
 Challenges 
According to Eduardo Navarro, the letters' contents were mysterious because few people knew about the Tupi language, Few systematic studies about the language, such as dictionaries, had been created.
Tupi was mostly a spoken language. As a result, the same word can be spelled a number of different ways.SAMPAIO 1906 In some cases, words were written separately, in others they were written as one word. Teodoro Sampaio also said this.SAMPAIO 1906
Other problems with the translation were that words were often abbreviated, but that not all people used the same abbreviations. Finally, there are differences in punctuation. What is more, the peope writing the letters were literate in Portuguese, the wrote their native language as they heard it. Like a Portuguese speaker, they wrote "taquesse" instead of "táxi". They also dd not use certain phonemes, nor puctuationb markers or accents.NAVARRO 2022 The letters also present a Tupi that was spoken in a colloquial way, which is different from the formal writings of the Jesuits.
 Content 
 Letters 
Roughly speaking, the pro-Portuguese natives asked those who were allied with the Dutch to return to the Portugese side, calling the Protestants heretics.NAVARRO 2005 This is the argument used by Filipe Camarão in his first letter to Pedro Poti, dated August 19, 1645. He also states that the Dutch are in "the Devil's fire".
Pedro Poti ordered that the messenger of such a letter be killed, and its answer is known only through Dutch summaries by Pastor Johannes Edwards,BARBOSA BARROS MONSERRAT 2020 because the Portuguese did not preserve the letters of the indigenous people. The cacique Pedro Poti is said to have criticized the Portuguese forcefully, saying that he could not switch to the Portuguese side, because they had only harmed his people by enslaving and killing them.
In general, the letters show that the Indians were disstified with the dituation they were in. They wanted their relatives to unitte, to stop fighting each other, and to go back to living according to their old traditions. They are desperate efforts in an attempt to save their people from destruction, The disruption of their traditional world is noticeable in all six letters.NAVARRO 2022
In his letters, Filipe Camarão tried to appeal to the sense of identity among the Potiguaras. He also assured Pedro Poti and Antônio Paraupaba that the natives would be forgiven if they went over to the Portuguese side, but said that if they resisted, they would be killed, since the honors bestowed by the Dutch on the natives were not valid for the PortuguesePedro Poti, when captured by the Portuguese, was tortured and, as predicted by Filipe Camarão, died. The exact location of his death is uncertain, so some say he died in a Portuguese prison, and others say he died in a ship bound for Portugal, where he would be judged. — when Europeans were captured, they were not killed, but turned into prisoners and used as bargaining chips.
 Legacy 
 Importance 
The letters are important today, because they are written by people who have always been oppressed. They were written by indigenous people.LODEWIJK 2006 The letters show that these people were not content with their situation. They also show that there were conflicts between the different Europeans, and that the native people wanted to rescue past traditions. The letters also bring to light previously unknown information, such as place names and other indigenous combatants, as well as revealing details about battles.
As far as the scientific study of language is concerned, the letters of the Camarão Indians are considered the most valuable documents in the field of Brazilian Indigenous linguistics indigenous linguistics pt Linguística indígena.NAVARRO 2022 They show how Old Tupi was actually spoken by the people writing the letters. They also show that the Jesuit missionaries correctly described the Tupi language. There are some scholars, such as Joaquim Mattoso Câmara Júnior pt who claim that the Jesuits adapted the language to their own interests, pejoratively calling it "Jesuit Tupi".'''NAVARRO 2022
Furthermore, the letters of the Camarão Indians also help to understand the linguistic evolution of Old Tupi, influenced by Portuguese. In fact, these writings display the use of the gerund in constructions analogous to the Portuguese "pt estou falando no" (I'm speaking), when it was Tupi's nature to invert this logic and say "falo estando" ([I] speak being).BARBOSA 1956
The letters also reveal the predominance of a subject-verb-object syntax (tpn aîmondó ã xe "soldados" ebapó — "pt eis que enviei meus soldados para aí no" [I have sent my soldiers there]), although there were still examples of subject-object-verb syntax (tpn emokûeî bé mokõî kunhã aîmondó — "pt para aí também duas mulheres enviei no" [there also two women I sent]), primitive Tupi tendency, as recorded in Quinhentismo quinhentist pt Quinhentismo texts.NAVARRO 2021
 Popular culture 
In March 2022, Natal mayor Álvaro Costa Dias pt met with Eduardo Navarro and agreed that the city would distribute didactic material about the letters to public school students and tourists. The mayor showed his intention to democratize the access to information about the correspondence between the Potiguaras.


Article Two of the United States Constitution: December 2013
Constitution of the United States of America#Article II Article Two of the United States Constitution
Article Two of the United States Constitution creates the executive branch of the United States government. The executive branch includes the President; the Vice President; the Cabinet; executive departments, like the Department of State; independent agencies, like the Central Intelligence Agency (CIA); and other things like committees and commissions.
Section 1Section 1: President and Vice President
Section 1, Clause 1Clause 1: Executive Power
Section One begins by giving federal executive power to the President only. This is part of the separation of powers that the Founding Fathers built into the Constitution. To prevent any part of the government from getting too powerful, they split the power between three branches. This clause gives executive power to the President. Another clause in Article One of the Constitution gives federal legislative (law-making) power to the United States Congress only. A third clause in Article Three gives judiciary power to the federal courts. No branch is allowed to do a job that the Constitution has given to another branch. For example, the President cannot make laws; that is the Legislature's job.
This clause says the President is the head of the Executive Branch. It also mentions the Vice President, though the Constitution does not give him any executive powers. However, the Constitution does say that the President and Vice President must be elected at the same time, for the same term (amount of time), and by the same constituency. The Founding Fathers wanted to make sure the Executive Branch would survive, and stay independent, if the Vice President had to become the President.
Section 1, Clause 2Clause 2: Method of choosing Electors
Under the U.S. Constitution, the President and Vice President are chosen by Electors. The Constitution allows each state legislature to decide how they will choose Electors. Since the 1820s, state legislatures have usually chosen Electors through an indirect popular vote. This means that people in the state will get to vote on which Electors they want. The ballot that people use to vote will have the Electors' names on it. Usually, it will also say what Presidential and Vice Presidential candidates they plan to support. This allows the people to choose Electors who support the candidates they like.
Each state has two United States Senators and a certain number of United States Representatives representing them in Congress. (The number of Representatives depends on how many people live in the state.) Each state gets a number of Electors that is equal to the number of Members of Congress the state has. (For example, if a state has 2 Senators and 10 Representatives, they have 12 total Members of Congress, so they get 12 Electors.)
The only people who cannot be Electors are Senators, Representatives, and federal officers. This is meant to make sure that the Electoral College is made up of regular Americans, not politicians.
Section 1, Clause 3Clause 3: Electors
This clause talks about Electors and how they choose a President. Once they are chosen, the Electors meet in their states to vote for the President and Vice President. Originally, candidates only ran for President; there were no candidates for Vice President. Each Elector voted for two different candidates for President. They had to vote for at least one candidate who did not live in the Elector's home state. The candidate who got more than half of the votes became President. The candidate who got the next highest number of votes (the second-place winner) became Vice President.
This clause gives instructions for several possible problems:
 Ties: 
 If two candidates get the same number of votes, the House of Representatives can choose which of the two candidates becomes President
 If there is a tie for Vice President (because two second-place candidates got the same number of votes), the Senate votes on which person should get the job
 No majority: 
 If no candidate wins more than half of the votes, then the House can choose any one of the five candidates who got the most votes
 Quorum:
 For the House and Senate to choose a President and Vice President, there must be a quorumA "quorum" is the fewest people that is needed in a group in order for the group to make important decisions. in both Houses of Congress. This means that a certain number of members of Congress have to be there for the vote:
 At least one Representative from two-thirds (67%) of the states in the House; AND
 At least two-thirds of the Senators in the Senate
Changes
The Twelfth Amendment changed this process in a few ways:
 Since it was passed in 1804, electors are only allowed to vote for one Presidential candidate and one Vice President. They do not have to vote for someone from a different state. 
 If no Presidential candidate gets a majority of votes, the House chooses from the top three candidates (not five). 
 The Vice President to get a majority of votes to be elected. If no Vice Presidential candidate gets a majority, the Senate chooses from the two candidates who got the most votes. 
 To be the Vice President, a person must meet the Constitution's requirements for being President (see Clause 5: Qualifications for office).
Section 1, Clause 4Clause 4: Election day
Article Two allows Congress to set a national Election Day.
Section 1, Clause 5Clause 5: Qualifications for office
This clause simply means that to be President, a person must meet three requirements:
 They must be a natural born citizen
 They are at least 35 years old
 They have lived in the United States for at least fourteen years
If a person does not meet all of these requirements, they cannot be President.
Note there is ongoing controversy over the exact meaning of "natural born citizen". The term has not been exactly defined in law. Neither has there been a definitive decision made by the Supreme Court on the meaning.
Changes
Two later amendments changed these rules about who can be President and Vice President:
The Twelfth Amendment (1804) says that to be Vice President, a person must meet all three of the requirements for President
The Twenty-second Amendment (1951) says a President cannot be elected more than twice
Section 1, Clause 6Clause 6: Vacancy and disability
This clause talks about the possibility that the Presidency might become "vacant". This might happen because:
 Congress takes away the President's job because he committed a crime (see Section 4: Impeachment)
 The President dies
 The President resigns
 The President is unable to do the things a President needs to do - for example, because he or she is very sick. This is called the Disability Clause.
If the Presidency becomes vacant, the Vice President becomes President. If the Vice President is also unable to be President, Congress can decide who will become President. Whoever takes over the Presidency will act as President until the actual President gets better (if he is sick or disabled), or until a President is elected in the next Presidential election.
Congress has come up with a "line of succession" a list of the people who would become President, and in what order, if both the Presidency and Vice Presidency became vacant. As of 2016, the order is: the Speaker of the House of Representatives; the President pro tempore of the Senate; and then the fifteen Cabinet Secretaries, in order of when their Departments were first created.
Changes
This clause was partially changed by the Twenty-fifth Amendment in 1967. That Amendment creates a process for filling a vacancy in the office of the Vice President. It also says that the Vice President can become Acting President (temporary President) if:
 The President himself says he cannot discharge his duties (he cannot do his job); OR 
 The Vice President, and most of the Cabinet, agree that the President cannot do his job. 
If the President declares himself unable to discharge his duties, he can take the Presidency back at any time. For example, in 2002, George W. Bush became the first President to formally use the Disability Clause. He gave power to his Vice President for about two hours while he had a medical test which required anesthesia. Once he felt ready to be President again, Bush took back the Presidency.
If the Vice President and the Cabinet say a President is unable to do his job, the President can still try to take control back. However, if the Vice President and the Cabinet still think the President cannot do his job, they can challenge the President's return. If two-thirds of both the House and Senate agree, the President is declared unable to discharge his duties and the Vice President stays in control of the Presidency.
Section 1, Clause 7Clause 7: Salary
This means the President can receive a salary. However, the salary cannot be changed during the President's four-year term in office. Also, the President cannot receive any other salary, either from the federal government, or from any state government.
Section 1, Clause 8Clause 8: Oath or affirmation
Before he becomes President, Clause 8 requires the new President to take an oath, promising that he will do his best as President, and will also do his best to protect and defend the Constitution. Usually, the Chief Justice of the United States gives the oath ("swears in" the new President) at the President's inauguration.
Section 2Section 2: Presidential powers
Section 2 talks about the powers that Article Two grants to the President.
Section 2, Clause 1Clause 1: Command of military; Opinions of cabinet secretaries; Pardons
The Constitution gives the President the most powers in areas that have to do with national security and protecting the country.
The President is the military's Commander-in-Chief. However, as part of the system of checks and balances in the Constitution, Article One says that only Congress can declare war. Still, the President can take actions like sending soldiers to certain places without needing Congress's approval, or a declaration of war.
The President may ask the "principal (head) officer" of any executive department to give him advice in writing. The Constitution actually does not require a formal Cabinet. However, America's first President, George Washington, organized his principal offices into a Cabinet, and every President has done the same since.
The President may grant pardons or reprieves to people who were convicted of crimes (except when the person was impeached). A "reprieve" cancels or changes a punishment for example, changing a death sentence to a sentence of life in prison.
Section 2, Clause 2Clause 2: Advice and Consent Clause
This part of Section 2 is called the Advice and Consent Clause. It gives the President powers, but he has to use them with the "advice and consent" (agreement) of the Senate. This is another example of checks and balances in the Constitution.
Treaties
Here, the Constitution gives the President the power to make treaties with other countries. However, two-thirds of the Senators must agree with the treaty for it to take effect. If two-thirds of the Senate does not agree with the treaty, it is not approved, and there is nothing the President can do about it.
The Constitution does not say how the United States can end a treaty. Since the Constitution has passed, the government has done this in a few ways. In 1798, the first time the government wanted to end a treaty (the 1778 Treaty of Alliance with France), Congress passed a law ending the treaty. Other times, in the 1800s, a few Presidents ended treaties after Congress asked them to. The first time a President ended a treaty without Congress's approval was in the 1970s, when President Jimmy Carter ended a treaty with the Republic of China. In a lawsuit called Goldwater v. Carter, members of Congress asked the Supreme Court to clarify whether a President could end a treaty on his own. The Supreme Court could not agree on a decision, and the case was dismissed (ended without a decision).
Appointments
The President may also choose judges, ambassadors, consuls (diplomats), ministers, and other officers; but again, he needs the advice and consent of the Senate.
If Congress chooses, it can let the President, heads of executive departments, or the courts appoint less important officials on their own, without needing Congress's approval.
Once the Senate gives advice and consent to the President (approves the President's choice for a job), and that person is given the job, the Senate cannot go back and change its mind. It cannot take away its advice and consent once the person gets the job.
However, after the Senate grants advice and consent, the President can change his mind, and decide not to give the job to the person he nominated.
It is not clear whether the President can fire a person who was hired with the advice and consent of the Senate. Congress has limited this power many times. For example, during the Reconstruction Era, President Andrew Johnson wanted to fire people that Congress had approved. Congress passed a law saying he could not do that, but Jackson ignored the law. Later, Congress impeached him, but the Senate did not convict him.
A Supreme Court case called Bowsher v. Synar (1986) decided that Congress can fire a person it approved. Congress can do this by repealing the law that gave the President permission to appoint that person.
Section 2, Clause 3Clause 3: Recess appointments
Clause 3 has to do with Senate recesses (times when the Senate is not meeting). In the past, fast transportation was not available, and it could take a long time for members of Congress to get to Washington, D.C. Because of this, Congress would usually meet only during planned "sessions," so everyone would have time to get there. After the planned sessions were over, the Senate would go into recess, and the Senators would go home.
During Senate recesses, the President may appoint officers to stand in for the missing Senators. However, these officers are temporary, and their permission to act as Senators expire (end) when the Senate finishes its next session.
Section 3Section 3: Presidential responsibilities
Section 3, Clause 1Clause 1: State of the Union
Clause 1 of Section 3 is called the State of the Union Clause. It says that "from time to time," the President must give Congress information on the "State of the Union." ("State of the Union" basically means "The Situation in the United States.")
Originally, Presidents personally delivered State of the Union Addresses to Congress every year. Thomas Jefferson thought this was too much like a King speaking from a throne. Instead, he would send Congress written messages, and clerks (assistants) would read them. Other Presidents did the same for over 100 years, until President Woodrow Wilson went back to speaking in front of Congress. Every President since Wilson has kept doing that 2016 to this day.
The purpose of the State of the Union is to make sure the President shares information with Congress, as well as the entire country. This information helps Congress decide whether anything is happening that they need to pass laws for. It also lets the people in the country know what is happening in their government.
Section 3, Clause 2Clause 2: Making recommendations to Congress
The President has the power to suggest to Congress anything he thinks is "necessary [needed] and expedient [appropriate]". This is called the Recommendation Clause.
The Recommendation Clause is another part of the checks and balances in the Constitution. The President cannot just do anything he thinks is needed; he has to get Congress's approval. If the President gives recommendations to Congress, Congress can approve them. However, if the President gives no suggestions to Congress, Congress has no power to force him to.
Also, just by asking Congress, the President shows that he respects them as equals, and is not more powerful or important than they are, like a King would be. One scholar explains: "The Recommendation Clause empowers the President to represent the people before Congress, by recommending measures for the reform of government, for the general welfare, or for the redress of grievances [for problems to be fixed]."p. 43
Section 3, Clause 3Clause 3: Calling Congress into extraordinary session; adjourning Congress
Clause 3 gives the President the right to call one or both Houses of Congress "on extraordinary Occasions." This clause is meant to allow the government to act quickly in case a major emergency comes up when Congress is not in session. If the two Houses of Congress cannot agree on a date for when to adjourn a special session, the President may adjourn both Houses whenever he thinks it is appropriate.
Presidents have called extraordinary sessions 27 times in history to deal with crises like wars or emergencies with the economy. The last time this happened was in 1948, when President Harry S Truman called a special session to try to get civil rights, Social Security, and health care laws passed.
After airplane travel became common around the 1950s, Congress began meeting year-round. Since that time, no President has had to call a special session.
Section 3, Clause 4 Reception ClauseClause 4: Receiving foreign representatives
The President receives (greets and hosts) all foreign Ambassadors. This clause of the Constitution is called the Reception Clause.
Section 3, Clause 5Clause 5: Caring for the faithful execution of the law
The President must "take care that the laws be faithfully executed [used and followed]." This clause in the Constitution is sometimes called the Take Care Clause, the Faithful Execution Clause, or the Faithfully Executed Clause.
This clause gives the President power, limits, and a duty, all at the same time:pp. 3–4
 It gives him the power to carry out the laws in any way that is legal and follows the Constitution
 It gives him the limit of not being able to ignore the laws. He cannot refuse to enforce a law or follow part of the Constitution
 It gives him the duty to carry out the laws (even if he disagrees with them). It also gives him the duty to make sure the rest of the government (including state governments) carry out the laws too
Supreme Court cases have focused on the duties and limits the Take Care Clause puts on the President. For example:
 The President must make sure everyone in the Executive Branch follows the laws made by Congress
 The President cannot stop enforcing, change, or ignore whatever laws he does not like. This is unconstitutional because it basically gives him power over lawmaking, and the Constitution gives that power only to Congress
 When Congress passes a law that approves money for a program, the President, or executive departments, cannot refuse to spend the money on that program. They cannot spend the money on anything else, because this would go against a law made by Congress.
Section 3, Clause 6Clause 6: Officers' commissions
The President commissions "all the Officers of the United States." (This means he gives these officers the power to do their jobs.) These include officers in both the military and foreign service (people who work for the United States government in other countries, like Ambassadors). However, Article One of the Constitution, Section 8, gives each state the power to appoint officers in their own militias.
Section 4Section 4: Impeachment
The Constitution also allows some government officials to be removed from office (fired). The President, Vice President, Cabinet Secretaries, and other executive officers, as well as judges, may be impeached by the House of Representatives, and then tried in the Senate.
Anyone who is convicted by impeachment is fired immediately. The Senate may also choose to prevent the person from holding any federal office in the future. These are the only punishments that an impeachment proceeding can give. However, the person can still be tried for civil and criminal charges in the courts, and punished if they are found guilty.
Impeachment is a power that only Congress has. In Nixon v. United States (1993), the Supreme Court ruled that even they cannot review or change the Senate's decision in an impeachment trial. Its impeachment powers give Congress a way to make sure that no executive officials or judges are getting corrupt.
 "High crimes and misdemeanors" 
The Constitution says clearly that officials can be impeached for treason or bribery. But it does not say exactly what "High crimes and Misdemeanors" includes or does not include. "High crimes" is a phrase from old British law that means crimes committed by people with political power. However, in British history, "high crimes and misdemeanors" could include many different things (even losing a ship by not tying it up). After the Constitution was written, Alexander Hamilton explained in The Federalist Papers what kind of causes for impeachment the Founders had in mind: "offences which [come] from the abuse or violation of some public trust. [They cause] injuries done immediately to the society itself."
Congress has made the meaning of "high crimes and misdemeanors" clearer by who they have chosen to impeach, and why. Since the Constitution was ratified, the House of Representatives has impeached 19 people - mostly judges, but also three Presidents.President Richard Nixon was going to be impeached in 1974 for obstruction of justice, abuse of power, and contempt of Congress. However, he resigned before the full House could decide whether to impeach him. All but three of these 19 were impeached for crimes other than treason or bribery.Judge West Hughes Humphreys (1862) was convicted of supporting the Confederacy; Judges Robert Woodrow Archbald (1912) and Alcee Hastings (1988) were convicted of bribery. For example:
 President Andrew Johnson was impeached in 1868 for breaking a federal law (he was acquitted by the Senate)
 President Bill Clinton was impeached in 1998 for perjury and obstruction of justice (he was acquitted)
 President Donald Trump was impeached twice. His first impeachment was in 2019 for abuse of power and obstruction of Congress and his second impeachment was in 2021 for incitement of insurrection (he was acquitted by the Senate both times)
 The judges were mostly impeached for:
 Being unfair, not being impartial, and making rulings that broke laws
 Abusing their power
 Being corrupt
 Tax evasion and lying about how much money they had


History of the United States: April 2020
History of the United States is what happened in the past in the United States, a country in North America.
Native Americans lived in the Americas for thousands of years. English people in 1607 went to the place now called Jamestown, Virginia. Other European settlers went to the colonies, mostly from England and later Great Britain. France, Spain, and the Netherlands also colonized North America. In 1775, a war between the thirteen colonies and Britain began when the colonists were upset over paying taxation to their government in the UK, but were not being given any chance to vote in the UK/British elections, to contribute to how that money was spent.
Just after dawn on April 19, 1775, the British attempted to disarm the Massachusetts militia at Concord, Massachusetts, thus beginning the war. On July 4, 1776, Founding Fathers wrote the United States Declaration of Independence. They won the American Revolutionary War and started a new country. They signed the constitution in 1787 and the Bill of Rights in 1791. General George Washington, who had led the war, became its first president. During the 19th century, the United States gained more land in the West and began to become industrialized. In 1861, several states in the South attempted to leave the United States to start a new country called the Confederate States of America. This caused the American Civil War. After the war, Immigration resumed. Some Americans became very rich in this Gilded Age, and the country developed one of the largest economies in the world.
In the early 20th century, the United States became a world power, fighting in World War I and World War II. Between the wars, there was an economic boom called the Roaring Twenties, when many people became richer, and a bust, called the Great Depression, when most were poorer. The Great Depression ended with World War II.
The United States and the Soviet Union entered the Cold War. This included wars in Korea and Vietnam. During this time, African-Americans, Chicanos, and women sought more rights. In the 1970s and 1980s, the United States started to make fewer things in factories. The country then went through the worst recession it had since the Great Depression. In the late 1980s, the Cold War ended, helping the United States out of recession. The Middle East became more important in American foreign policy, especially after the September 11 attacks and War on terror in 2001. In the 2010s, Barack Obama's presidency helped many domestic problems in the country such as the auto business and healthcare coverage. After Obama, the country saw a rise in populist politics with the presidency of Donald Trump. In 2020, the country oversaw the COVID-19 pandemic, social unrest over racial justice and disputes over the 2020 election results which led to violent reactions.
 Pre-Columbian America 
History of North America
The Pre-Columbian Era is the time before Christopher Columbus went to the Americas in 1492. At that time, Native Americans lived on the land that is now controlled by the United States. They had various cultures: Native Americans in the Eastern Woodlands hunted game and deer; Native Americans in the Northwest fished; Native Americans in the Southwest grew corn and built houses called pueblos; and Native Americans in the Great Plains hunted Bison. Around the year 1000, the Vikings visited Newfoundland. However, they did not settle there.
 Colonial America 
The English tried to settle at Roanoke Island in 1585. The settlement did not last, and no one knows what happened to the people. In 1607, the first lasting English settlement was made at Jamestown, Virginia, by John Smith, John Rolfe and other Englishmen interested in gold and adventure. In its early years, many people in Virginia died of disease and starvation. The colony in Virginia lasted because it made money by planting tobacco, rice and cotton.
In 1621, a group of Englishmen called the Pilgrims settled at Plymouth, Massachusetts. A bigger colony was built at Massachusetts Bay by the Puritans in 1630. The Pilgrims and the Puritans were interested in making a better society, not looking for gold. They called this ideal society a "city on a hill". A man named Roger Williams left Massachusetts after disagreeing with the Puritans, and started the colony of Rhode Island in 1636.
Great Britain was not the only country to settle what would become the United States. In the 1500s, Spain built a fort at St. Augustine, Florida. France settled Louisiana, and the area around the Great Lakes. The Dutch settled New York, which they called New Netherland. Other areas were settled by Scotch-Irish, Germans, and Swedes. However, in time Britain controlled all of the colonies, and most American colonists adopted the British way of life. The growth of the colonies was not good for Native Americans. Many of them died of smallpox, a disease brought to America by the Europeans. The ones who lived lost their lands to the colonists.
In the early 1700s, there was a religious movement in the colonies called the Great Awakening. Preachers such as Jonathan Edwards preached sermons. One of them was called "Sinners in the Hands of an Angry God". The Great Awakening may have led to the thinking used in the American Revolution.
By 1733, there were thirteen colonies. New York City, Philadelphia, Boston, and Charleston were the largest cities and main ports at that time.
From 1756 to 1763, England and France fought a war over their land in America called the Seven Years' War or the French and Indian War, which the British won. After the war, the Royal Proclamation of 1763 said that the colonists could not live west of the Appalachian Mountains. Many colonists who wanted to move to the frontier did not like the Proclamation.
 American Revolution 
After the French and Indian War, the colonists began to think that they were not getting their "rights as freeborn Englishman". This meant they wanted to be treated fairly by the English government. This was mainly caused by new taxes the British made the colonies pay to pay for the war. Americans called this "No taxation without representation", meaning that the colonists should not have to pay taxes unless they had votes in the British Parliament. Each tax was disliked, and replaced by another which led to more unity between the colonies. In 1770, colonists in Boston known as the Sons of Liberty got in a fight with British soldiers. This became known as the Boston Massacre. After the Tea Act, the Sons of Liberty dumped hundreds of boxes of tea in the sea. This was known as the Boston Tea Party (1773). This led to the British Army taking over Boston. After that, leaders of the 13 colonies formed a group called the Continental Congress (1774). Many people were members of the Continental Congress, but some of the more important ones were Benjamin Franklin, John Adams, Thomas Jefferson, John Hancock, Roger Sherman and John Jay.
In 1776, Thomas Paine wrote a pamphlet called Common Sense. It argued that the colonies should be free of English rule. This was based on the English ideas of natural rights and social contract put forth by John Locke and others. On July 4, 1776, people from the 13 colonies agreed to the United States Declaration of Independence. This said that they were free and independent states, and were not part of England any more. The colonists were already fighting Britain in the Revolutionary War at this time. The Revolutionary War started in 1775 at Lexington and Concord. Though American soldiers under George Washington lost many battles to the British, they won a major victory at Saratoga in 1777. This led to France and Spain joining the war on the side of the Americans. In 1781, an American victory at Yorktown helped by the French led Britain to decide to stop fighting and give up the colonies. America had won the war and its independence.
 The Federal Period (1781–1815) 
United States Constitution War of 1812
In 1781, the colonies formed a confederation of states under the Articles of Confederation, but it lasted only six years. It gave almost all the power to the states and very little to the central government. The confederation had no president. It could not remove Native Americans or the British from the frontier, nor could it stop mob uprisings such as Shays' Rebellion. After Shays' Rebellion, many people thought the Articles of Confederation were not working.
In 1787, a constitution was written. Many of the people who helped write the Constitution, such as Washington, James Madison, Alexander Hamilton and Gouverneur Morris, were among the major thinkers in America at the time. Some of these men would later hold important offices in the new government. The constitution created a stronger national government that had three branches: executive (the President and his staff), legislative (Congress, the House of Representatives and the Senate), and judicial (the federal courts).
Some states agreed to the Constitution very quickly. In other states, many people did not like the Constitution because it gave more power to the central government and had no bill of rights. To try and get the Constitution passed, Madison, Hamilton and Jay wrote a series of newspaper articles called the Federalist Papers. Very soon after, the Bill of Rights was added. This was a set of 10 amendments (changes), that limited the government's power and guaranteed rights to the citizens. Like the Declaration of Independence, the Constitution is a social contract between the people and the government. The main idea of the Constitution is that the government is a republic (a representative democracy) elected by the people, who all have the same rights. However, this was not true at first, when only white males who owned property could vote. Because of state laws as well as the 14th, 15th, 19th, 24th and 26th Amendments, almost all American citizens who are at least 18 years old can vote today.
In 1789, Washington was elected the first President. He defined how a person should act as President and retired after two terms. During Washington's term, there was a Whiskey Rebellion, where country farmers tried to stop the government from collecting taxes on whiskey. In 1795, Congress passed the Jay Treaty, which allowed for increased trade with Britain in exchange for the British giving up their forts on the Great Lakes. However, Great Britain was still doing things that hurt the U.S., such as impressment (making American sailors join the British Royal Navy).
John Adams defeated Thomas Jefferson in the election of 1796 to become the second President of the United States. This was the first American election that was between two political parties. As president, Adams made the army and navy larger. He also got the Alien and Sedition Acts passed, which were much disliked.
In the election of 1800, Jefferson defeated Adams. One of the most important things he did as President was to make the Louisiana Purchase from France, which made the United States twice as big. Jefferson sent Lewis and Clark to map the Louisiana Purchase. Jefferson also tried to stop trade with England and France so that the United States would not become involved in a war the two countries were fighting. Fighting broke out between the United States and England in 1812 when James Madison was President. This was called the War of 1812.
 Expansion, Industrialization, and Slavery (1815–1861) 
One of the problems of this period was slavery. By 1861, over three million African-Americans were enslaved in the South. This means that they worked for other people, but had no freedom and received no money for their work. Most worked picking cotton on large plantations. Cotton became the main crop in the South after Eli Whitney invented the cotton gin in 1793. There were a few slave rebellions against slavery, including one led by Nat Turner. All of these rebellions failed. The South wanted to keep slavery, but by the time of the Civil War, many people in the North wanted to end it. Another argument between the North and South was about the role of government. The South wanted stronger state governments, but the North wanted a stronger central government.
After the War of 1812 the Federalist Party faded away, leaving an "Era of Good Feelings" in which only one party was important, under Presidents James Madison and James Monroe. Under Monroe, the United States' policy in North America was the Monroe Doctrine, which suggested that Europe should stop trying to control the United States and other independent countries in the Americas. Around this time, Congress called for something called the "American System". The American System meant spending money on banking, transportation and communication. Due to the American System, bigger cities and more factories were built. One of the big transportation projects of this time was the Erie Canal, a canal in the state of New York. By the 1840s, railroads were built as well as canals. By 1860, thousands of miles of railroads and telegraph lines had been built in the United States, mostly in the Northeast and Midwest.
In the early 19th century, the industrial revolution came to America. Many factories were built in Northern cities such as Lowell, Massachusetts. Most of them made clothes. Many factory workers were women, and some were children or people from Ireland or Germany. Despite this industrialization, America was still a nation of farmers.
In the early and mid-1800s, there was a religious movement called the Second Great Awakening. Thousands of people gathered at large religious meetings called revivals. They thought they could bring about a Golden Age in America through religion. New religious movements such as the Holiness Movement and the Mormons started, and groups like the Methodist Church grew. The Second Great Awakening led to two movements in reform, that is, changing laws and behaviors to make society better. One of these was the Temperance movement, which believed that drinking alcohol was evil. The other was abolitionism, which tried to end slavery. People such as Harriet Beecher Stowe and William Lloyd Garrison wrote books and newspapers saying that slavery should stop. They also formed political movements, which included the Liberty Party, the Free Soil Party and the Republican Party. Some abolitionists, such as Frederick Douglass, were former slaves. By 1820, slavery was very rare in the North, but continued in the South.
In the 19th century, there was something called the “cult of domesticity” for many American women. This meant that most married women were expected to stay in the home and raise children. As in other countries, American wives were very much under the control of their husband, and had almost no rights. Women who were not married had only a few jobs open to them, such as working in clothing factories and serving as maids. By the 19th century, women such as Lucretia Mott and Elizabeth Cady Stanton thought that women should have more rights. In 1848, many of these women met and agreed to fight for more rights for women, including voting. Many of the women involved in the movement for women’s rights were also involved in the movement to end slavery.
In 1828, Andrew Jackson was elected President. He was the first president elected from the Democratic Party. He changed the government in many ways. Since many of his supporters were poor people who had not voted before, he rewarded them with government jobs, which is called "spoils" or "patronage". Because of Jackson, a new party was formed to run against him called the Whigs. This was called the "Second Party System". Jackson was very much against the National Bank. He saw it as a symbol of Whigs and of powerful American businessmen. Jackson also called for a high import tax that the South did not like. They called it the "Tariff of Abominations". Jackson’s Vice-President, John C. Calhoun, was from the South. He wrote that the South should stop the tariff and perhaps leave the Union (secession). These words would be used again during the Civil War.
People started to move west of the Mississippi River and the Rocky Mountains at this time. The first people who moved west were people who caught and sold animal skins such as John Colter and Jim Bridger. By the 1840s, many people were moving to Oregon by wagon, and even more people went west after the California Gold Rush of 1849. Many new states were added to the first thirteen, mostly in the Midwest and South before the Civil War and in the West after the Civil War. During this period, Native Americans lost much of their land. They had lost military battles to the Americans at Tippecanoe and in the Seminole War. In the 1830s, Indians were being pushed out of the Midwest and South by events such as the Trail of Tears and the Black Hawk War. By the 1840s, most Native Americans had been moved west of the Mississippi River.
 The MexicanAmerican War (1846—1848) 
In 1845, Texas, which was a nation after it left Mexico, joined the United States. Mexico did not like this, and the Americans wanted the land Mexico had on the West Coast (“Manifest destiny”). This led to the U.S. and Mexico fighting a war called the Mexican–American War. During the war, the U.S captured the cities of San Francisco, Los Angeles, Monterrey, Veracruz and Mexico City. As a result of the war, the U.S. gained land in California and much of the American Southwest. Many people in the North did not like this war, because they thought it was just good for Southern slave states.
 Civil War 
In the 1840s and 1850s, people in the Northern states and people in the Southern states did not agree whether slavery was right or wrong in the territories—parts of the United States that were not yet states. People in the government tried to make deals to stop a war. Some deals were the Compromise of 1850 and the Kansas-Nebraska Act, but they did not really work to keep the Union together. People in the South were angry at books like Uncle Tom's Cabin that said that slavery was wrong. People in the North did not like a Supreme Court decision called Dred Scott that kept Scott a slave. People from the South and people from the North started killing each other in Kansas over slavery. This was called "Bleeding Kansas". One of the people from Bleeding Kansas, John Brown, took over a town in Virginia in 1859 to make a point about slavery being wrong and to try to get slaves to fight their owners.
In the election of 1860, the Democratic Party split and the Republican candidate for President, Abraham Lincoln, was elected. After this, many Southern states left the Union. Eventually, eleven states left. They tried to start a new country called the Confederate States of America, or the "Confederacy". A war started between the Union (North) and the Confederacy (South). Not having factories made it harder for Southern soldiers to get guns or uniforms. The South could not get supplies because Northern ships blockaded the Southern coast.
Early in the war, Confederate generals such as Robert E. Lee and Stonewall Jackson won battles over Union generals such as George B. McClellan and Ambrose Burnside. In 1862 and 1863, the Union Army tried to take the Confederate capital of Richmond, Virginia several times, but failed each time. Lee's army invaded the North twice, but was turned back at Antietam and Gettysburg. In the middle of war, Lincoln made the Emancipation Proclamation, which freed all slaves in the Confederacy, and started letting black men fight in the Union Army. The war started going the Union’s way after the battles of Gettysburg and Vicksburg in 1863. Gettysburg stopped Lee from invading the North, and Vicksburg gave the Union control over the Mississippi River. In 1864, a Union Army under William T. Sherman marched through Georgia and destroyed much of it. By 1865, Union General Ulysses S. Grant had taken Richmond and forced Lee to give up the fight at Appomattox.
 Reconstruction and the Gilded Age 
Reconstruction of the United States
In April 1865, Lincoln was shot and killed while watching a play. The new president, Andrew Johnson, had to go through the process of reconstruction, which was putting the United States back together after the Civil War. During this time, the 13th, 14th, and 15th Amendments to the Constitution were passed, freeing slaves, making them citizens and allowing them to vote. Congress was run by "Radical Republicans", who wanted to punish the South after the Civil War, and they did not like Johnson, who almost got removed from office. They also sent many soldiers to the South, installed unpopular "scalawag" governments, and made the South pass the 14th and 15th Amendments. The South did not like this, so they made "Jim Crow" laws that placed blacks in lower roles. White Southern Democrats started a group called the Ku Klux Klan that attacked blacks and stopped them from voting.
During this time, many people moved to the United States from other countries, such as Ireland, Italy, Germany, Eastern Europe, and China. Many of them worked in large factories and lived in big cities, such as New York City, Chicago, and Boston, often in small, poor, close-together apartments called "tenements" or "slums". They often were used by "political machines", who gave them jobs and money in exchange for votes.
Major politicians were chosen by political machines and were corrupt. The government could do little and leaders of big businesses often had more power than the government. At this time, there were several very big businesses called trusts. People who ran trusts made millions of dollars while paying their workers low wages. Some of these people were John D. Rockefeller, Andrew Carnegie, and J. P. Morgan.
After the Civil War, people continued to move west where new states were formed. People now could get free land in the West due to an 1862 law called the Homestead Act. Most of the land in the West was owned by the government, railroads, or large farmers. The Transcontinental Railroad, finished in 1869, helped get people and goods from the west to the rest of the country. Chicago became the center of trade between West and East because many rail lines met there. There were problems between the white settlers and the native Indians as more people began to move west. Because of this, many more Indians were killed at battles such as Wounded Knee. Almost all the Indians' land was taken away by laws like the Dawes Act.
Many Americans thought the railroads charged farmers so much money that it made them poor. Workers led several strikes against the railroad that were put down by the army. Also, farmers started groups to fight the railroad, such as the Grange. These groups became the Populist Movement, which almost won the presidency under William Jennings Bryan. The Populists wanted reforms such as an income tax and direct election of Senators. The Populist Party died out after 1896. Many of the things the Populists wanted would happen during the Progressive Era.
 Progressive era and imperialism 
In the United States, progressivism is the belief that the government should have a larger role in the everyday life of Americans to provide good living standards for people, especially workers. Imperialism was the belief that the U.S. should build a stronger navy and conquer land.
In the late nineteenth and early 20th centuries, the U.S. started being more active in foreign affairs. In 1898, the United States fought a war with Spain called the Spanish–American War. The United States won, and gained Puerto Rico, Guam, Guantanamo and the Philippines. Combined with the purchase of Alaska and the taking-over of Hawaii, the United States had gained all the territory it has today, plus some it would later lose after World War II. Around this time, the U.S. and European nations opened up trade with China. This was because they had beaten China in the Opium Wars and the Boxer Rebellion. The U.S. and Europe were able to trade with China through the Open Door Policy.
In 1901, Republican Theodore Roosevelt became President. He had been a soldier in the Spanish–American War. He called for a foreign policy known as the "Big Stick". This meant having a large navy and exercising control over Latin America. Between 1901 and 1930, the United States sent soldiers into Latin America several times. When Roosevelt was president, work was begun on the Panama Canal, a link between the Pacific and Atlantic Oceans that made travel around the world much faster.
During this time, people started to notice the poor condition of American cities. A group of people called the “muckrakers” wrote books and newspaper articles about subjects like the power of big business, unclean practices in factories, and the condition of poor people. Roosevelt and Congress answered their concerns with laws such as the Pure Food and Drug Act. The Act controlled the way food was made to make sure it was safe. Another response to the muckrakers was something called "trust-busting", where big businesses were broken up into smaller ones. The biggest business broken up this way was the Standard Oil Company in 1911.
In 1912, Woodrow Wilson became President. He was a Progressive, but not quite the same as Roosevelt. He fought the "triple wall of privilege", which was big business, taxes, and fees on goods coming into the United States. During this time, the Sixteenth and Seventeenth Amendments to the U.S. Constitution were passed. They allowed for a federal income tax and direct election of U.S. Senators.
 World War I 
The United States did not want to enter World War I but wanted to sell weapons to both sides. In 1915 a German submarine sank the RMS Lusitania, a Cunard Line ship carrying Americans. This angered Americans, and Germany stopped attacking passenger ships. In January 1917 Germany started attacking them again, and sent the Zimmermann Telegram to Mexico about invading the U.S. The United States joined the war against Germany, and it ended a year and a half later. Wilson worked to create an international organization called the League of Nations. The main goal of the League was preventing war. However, the United States did not join because isolationists rejected the peace treaty. At the end of World War I, a flu pandemic killed millions of people in the U.S. and Europe. After the war, the United States was one of the richest and most powerful nations in the world.
 Boom and bust (1919–1939) 
 The "Roaring Twenties" 
The 1920s were an era of growth and increased wealth for the United States. Many Americans began buying consumer products, such as Ford Model T and appliances. Advertising became very important to American life. During this time, many black people moved out of the South and into large cities such as New York City, Chicago, St. Louis and Los Angeles. They brought with them jazz music, which is why the 1920s are called the "Jazz Age". The 1920s were also the Prohibition Era after the 18th Amendment passed. During the 1920s, drinking alcohol was illegal, but many Americans drank it anyway. This led to much rum-running and violent crime.
Racism was strong in the 1920s. The Ku Klux Klan was powerful once again, and attacked black people, Catholics, Jews and immigrants. People blamed the war and problems in business on immigrants and labor leaders, whom they said were Bolsheviks (Russian communists). Many people also thought that the United States had lost touch with religion. They handled that by changing religion, and some of them by attacking science.
After World War I, the United States had an isolationist foreign policy. That meant it did not want to enter into another global war. It passed laws and treaties that supposedly would end war forever, and refused to sell weapons to its former allies.
In 1921, Warren G. Harding became President. He believed that the best way to make the economy good was for the government to be friendly to big business by cutting taxes and regulating less. While the economy was doing very well under these policies, America had the largest difference between how much money the rich had and how much money the poor had. Harding's presidency had several problems. The biggest one was Teapot Dome over oil drilling in the Navy Oil Reserve. Harding died in 1923, and Calvin Coolidge became President. Coolidge believed that the government should keep out of business, just like Harding, and continued many of Harding's policies. Coolidge chose not to seek the presidency in 1928 and Herbert Hoover became president.
 The Great Depression 
Great Depression New Deal
In 1929, a Great Depression hit the United States. The stock market crashed (lost much of its value). Many banks ran out of money and closed. By 1932, over a quarter of the nation had no jobs, and much of the nation was poor or unemployed. Many people were driven off farms, not only because of the Depression, but also because of a storm known as the "Dust Bowl" and because farmers had not been doing well during the 1920s.
President Hoover tried to do something about the Depression, but it did not work. In 1932, he was defeated and Franklin D. Roosevelt became President. He created the New Deal. It was a series of government programs which would give relief (to the people who were hurt by the bad economy), recovery (to make the economy better), and reform (to make sure a depression never happens again).
The New Deal had many programs such as Social Security, the National Recovery Administration (regulated wages), Works Progress Administration (built thousands of roads, schools, government buildings and works of art), the Civilian Conservation Corps (gave young people jobs to help the environment), and Tennessee Valley Authority (built dams and electric lines in the South). These programs put millions of Americans to work, though often at low pay. Many of these programs were started early in Roosevelt's term in a time called the "Hundred Days" or in 1935 in a time called the "Second New Deal". Programs like Social Security grew out of populist movements by people such as Huey Long that were called "Share Our Wealth" and "Ham and Eggs". The New Deal also led to the rise of worker's unions such as the Congress of Industrial Organizations.
The New Deal is often called the period that "saved capitalism", and stopped America from becoming a Communist or Fascist state. Although the New Deal improved the economy, it did not end the Great Depression. The Great Depression was ended by World War II.
 World War II 
As World War II was beginning, the United States said they would not get involved in it. Most Americans thought the United States should remain neutral, and some people thought the United States should enter the war on the side of the Germans. Eventually, the U.S. did try to help the Allied Powers (Soviet Union, Britain, and France) with the Lend Lease Act. It gave the Allies a lot of money and guns in trade for use of air bases throughout the world.
On December 7, 1941, Japan attacked Pearl Harbor, a U.S.Naval base in Hawaii. The U.S. was no longer neutral, and it declared war on the Axis Powers (Germany, Japan, Italy). The U.S. entering World War II ended the Great Depression because the war created many jobs. While some of the battles the U.S. fought in were air and naval battles with Japan, the U.S. mainly fought in Europe and Africa. The U.S. opened up several fronts, including in North Africa and Italy. The U.S. also bombed Germany from airplanes, blowing up German cities and factories. On June 6, 1944 (D-Day), American and British forces invaded Normandy. A year later, the Allies had freed France and taken Berlin. In 1945, Roosevelt died, and Harry Truman became president. The U.S. decided to drop two atomic bombs on Japan. Japan gave up soon afterwards, and the war ended.
The war meant different things for women and minorities. During the war, many women worked in weapons factories. They were symbolized by a character called "Rosie the Riveter". Many African-Americans served in the army, but often in segregated units with white officers. Japanese-Americans on the West Coast were forced to live in internment camps, though a few also served in the Army.
 Postwar era (1945–1991) 
 Cold War 
Korean War Vietnam War Cuban Missile Crisis Space Race Reagan Era
After World War II, the Soviet Union and the United States were the two most powerful countries left in the world. The Cold War was a period of tension between the two countries over ways of life. The two countries tried to get other countries on their side. The Soviet Union tried to get countries to become Communist and the United States tried to stop them from being Communist. American and Soviet soldiers never fought in battles, but they fought indirectly in the Korean War (1950s) and the Vietnam War (1950s–1970s).
The Korean War lasted only a few years, but led to American soldiers being in Korea since then. The Vietnam War lasted much longer. It started with a few American troops in Vietnam, but by the 1960s thousands of Americans were being sent to Vietnam. Both wars were between a Northern Communist government helped by the Soviet Union and Communist China and a Southern government helped by the U.S. The Korean War resulted in a split Korea, but the Vietnam War resulted in a Communist Vietnam after the United States left due to American people wanting to end the war. Over a quarter million Americans died or were wounded in Vietnam, which was very much a military failure. The U.S. and Soviet Union argued about where they could place nuclear weapons. One of these arguments was the Cuban Missile Crisis. During the Cuban Missile Crisis, the U.S. and Soviet Union came very close to attacking each other with nuclear weapons.
During the Cold War, the United States had a "Red Scare" where the government tried to find people it thought were Communist. The House of Representatives had a group called the House Un-American Activities Committee to deal with this, and Joseph McCarthy led hearings in the Senate. The Red Scare led to people losing their jobs, going to jail, and even being executed. Many actors and authors were put on blacklists, which meant they could not get jobs in movies or get credit for their writings.
The Cold War began with an arms race between the United States and the Soviet Union to see who could have more and better weapons. This started after the Soviets were the second country to develop an atomic bomb. In the United States, this started something called the "Military Industrial Complex", which meant business and government working together to spend a lot of money on large-scale weapons projects. Business and government helped each other to get more money and more power. Part of the Complex was something called the Marshall Plan, which rebuilt Europe while making them buy American goods. The Complex allowed for a growing middle class, but also kept the Cold War going.
Besides the arms race, another part of the Cold War was the "Space Race". This started when the Soviets launched a satellite into space called Sputnik in 1957. Americans became worried that the United States was falling behind the Soviet Union, and made their schools focus more on mathematics and science. Within a few years, both the United States and the Soviet Union had sent satellites, animals and people into orbit. In 1969 the Apollo 11 mission put Neil Armstrong and Buzz Aldrin on the Moon.
United States foreign policy changed in the 1970s when the United States left Vietnam and Richard Nixon left office due to a political scandal called Watergate. In the 1970s and 1980s, the United States had a policy of "detente" with the Soviet Union. This meant that the two countries signed treaties to stop use of weapons. Under Nixon and Reagan, the United States sent troops and money to many Latin American governments to stop them from being Communist. This led to violence in Latin America. Around this time, the economy suffered because the United States was not making as many things as it used to, and because some countries in the Middle East were not giving the U.S. as much oil as it wanted (this was called an "oil embargo"). The Middle East became very important in American foreign policy after several Americans were kidnapped in Iran in 1979. In the 1980s, people in the U.S. government sold weapons to people in Iran and gave the money to "contra" soldiers in Nicaragua. This was called the "Iran-Contra affair". In the 1970s and 1980s, the U.S. normalized relations with China. The Cold War came to an end as Communist governments in the Soviet Union and other countries fell apart.
 Domestic and social issues 
The United States once again had prosperity. Millions of white people moved out of the cities and into suburbs, and into Southern and Western states known as the "Sunbelt". They bought new cars and television sets. The birth rate in the 1940s and 1950s rose, in what was called the "Baby Boom" The "Space Age" inspired "Googie" style art and architecture. Many more people became part of the middle class, but there were still many people who were poor.
Poverty was most common among African-Americans. Most lived in poor neighborhoods in Northern cities, or in the South where they faced racism and "Jim Crow" segregation. These conditions led to the Civil Rights Movement of the 1950s, led by Martin Luther King Jr. and others. In 1954, the Supreme Court found school segregation illegal in Brown v. Board of Education, though it would be several years before school segregation was ended. In 1955, King led a bus boycott in Montgomery, Alabama. In the late 1950s and 1960s, King got help from Presidents John F. Kennedy, who was shot, and Lyndon B. Johnson. In 1963, he led a march on Washington calling for civil rights. Soon after, Congress passed laws that made most segregation illegal. Johnson also passed a program called the Great Society that helped poor people and minorities.
Gays and lesbians, who had often been persecuted, also started to ask for rights, beginning with the Stonewall riots in 1969. Chicanos, Native Americans, old people, consumers, and people with disabilities also fought for rights, as did women. Though women had had jobs during World War II, most of them went back to the home after the war. Women did not like that they often held jobs that paid less than men or that fewer opportunities were open to them. People like Betty Freidan and Gloria Steinem founded groups such as the National Organization for Women to try and solve these problems. NOW and other groups wanted an Equal Rights Amendment that would guarantee them equality in all areas. In the 1970s and 1980s, many more jobs and opportunities were opened to women. There were some women like Phyllis Schlafly who opposed Freidan and Steinem and were known as "anti-feminists". It was partly because of the anti-feminists that the Equal Rights Amendment was defeated, but also because women had already gained equality in many areas and they did not want to be drafted into the army.
In the 1960s, the counterculture was created. Some of the followers of the counterculture were called hippies. They had long hair, and lived communally, smoking marijuana and practicing free love. The counterculture, along with college students, were the groups most against the Vietnam War. They also were the groups that listened to new music known as rock and roll.
In 1973, the Supreme Court issued a decision called Roe v. Wade, which made many abortions legal. The many changes led to a reaction by Jerry Falwell and other conservatives who called themselves the "Religious Right" and the "Moral Majority".
 Reagan Era 
Ronald Reagan was elected President in 1980. He defeated incumbent Jimmy Carter by winning 44 out of the 50 American states. During the Reagan Era, the country was facing through inflation, a bad economy, and the American foreign policy were not as good. When Ronald Reagan became president, he signed the Economic Recovery Tax Act of 1981 which lowered taxes for corporations, supposedly so they could reinvest the surplus profits back into business. During Reagan's presidency, he expanded the American military creating more jobs, but also raising the deficit due to overspending. During his first term, the economy went from a 4.5% to 7.2%.
In 1984, Reagan won in a major landslide by winning 49 out of the 50 American states. During his second term, Reagan focused on ending the Cold War. He held many meetings between Margaret Thatcher, Pope John Paul II, and Soviet leader Mikhail Gorbachev. They first met at the Geneva Summit in 1985. Later they both discovered their passion of ending the war. Reagan met four times with Soviet leader Mikhail Gorbachev, who ascended to power in 1985, and their summit conferences led to the signing of the Intermediate-Range Nuclear Forces Treaty.
Also during his second term, Reagan's Invasion of Grenada and bombing of Libya were popular in the US, though his backing of the Contras rebels was mired in the controversy over the Iran–Contra affair that revealed Reagan's poor management style.
Since leaving office in 1989, Reagan became one of the most popular Presidents of the United States.
Post-Cold War and beyond (1991–present) 
Post-Cold War era
In the late 1980s and early 1990s, Republican President Ronald Reagan brought the Cold War to an end. This was due to the Russian leader Mikhail Gorbachev starting a policy called perestroika, the fall of the Berlin Wall, and the Soviet Union breaking into different countries. Around this time, the United States cut down on its production of cheap goods, and had many people working in service jobs. Part of these service jobs were in computers and the internet, which came into wide use in the 1990s. By this time, the United States had a very large trade deficit, meaning it received more goods from other countries, such as China, than it sent to other countries.
The Middle East became the main focus of U.S. foreign policy. In 1991, the United States fought a war with Iraq called the First Gulf War or Operation Desert Storm. This was to stop Iraqi leader Saddam Hussein from occupying Kuwait, a small oil-producing country.
In 1992, Bill Clinton became President. Under Clinton, the United States sent soldiers into Bosnia as part of a United Nations mission. The United States also agreed to a trade pact called the North American Free Trade Agreement (and repealed Glass–Steagall Legislation). Clinton was impeached for lying in court about his relationship with Monica Lewinsky, but the Senate voted against removing him as President.
 21st century 
Bush presidency
In 2000, George W. Bush was elected President. Terrorists attacked the World Trade Center on September 11, 2001. Thousands of people died. Soon after the attacks, the U.S. and NATO went to Afghanistan to find Osama bin Laden and others who they believed planned the September 11 attacks. In 2003, the United States invaded Iraq. The wars in Iraq and Afghanistan have lasted many years. By 2011, American soldiers started leaving Iraq, and combat there started to slow down.
In 2005, the southern United States was hit by Hurricane Katrina. Much of the city of New Orleans was destroyed. In 2006, the Democrats won back Congress because Americans did not like the way Bush dealt with War in Iraq or Katrina.
Obama presidency
Barack Obama was elected President in 2008. The United States had entered the worst recession since the Great Depression a while before. Barack Obama was the first African-American President of the United States. During his first years in office, Obama and Congress passed reforms on health care and banking, skyrocketing the cost of health insurance. They also passed a large stimulus bill to try to help the economy during the recession, but it only ultimately extended it's duration. During the recession, the government used large amounts of money to keep the banking and auto industries from falling apart. There was also a large oil spill in the Gulf of Mexico. In 2010, Congress passed the Patient Protecton and Affordable Care Act, a sweeping overhaul of the health care system. Dubbed "Obamacare", it was faced with fierce criticism from conservative media, as it exponentially increased the cost of health care. However, it was praised by Democrats who said it helped give more people access to healthcare. It continues to be a big deal to this day.
A "Tea Party movement" started during Obama's presidency. This group opposes Obama's health care plan and other policies they see as "big government." Due to the recession, the Tea Party and a dislike of what Obama did, Republicans won a large number of House and Senate seats in the 2010 election. In 2011, Tea Party members of Congress almost shut down the government and sent the U.S. into default (not being able to pay people the government owes money). A few months later, many young people protested against organized and concentrated wealth during the Occupy movement. In 2012, Obama was reelected to a second term. Following reelection, Obama faced major obstruction from Congressional Republicans. This polarization in the political atmosphere and the media, lead to events such as the 2013 Federal Government Shutdown and the stalling of Obama's Supreme Court pick, Judge Merrick Garland to replace Justice Antonio Scalia. In 2014, Republicans took control of both houses of Congress, further adding to the gridlock. In foreign policy, President Obama helped craft the Paris Climate Agreement, a major global commitment to fighting "climate change". He also forged the Iran Nuclear Agreement, which was widely seen as an enormous failure. He also opened relations with Cuba for the first time in fifty years.
First Trump presidency
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  House Speaker Nancy Pelosi announces the vote count on Article I and II of House Resolution 755.
The 2016 presidential election attracted much attention. Main popular candidates of the election were Republicans Donald Trump and Senator Ted Cruz and Democrats Hillary Clinton and Senator Bernie Sanders. Trump and Clinton won their respective primaries. On November 9, 2016, Trump defeated Clinton, despite most polls saying otherwise. At 70 years old, Trump became the oldest person elected to the presidency, and the first with no prior military or government experience. Trump was inaugurated on January 20, 2017. Afterwards, there were many protests against Trump across the country.
On January 27, President Trump signed an executive order that stopped refugees from entering the country for 120 days and denied entry to citizens of Iraq, Iran, Libya, Somalia, Sudan, Syria, and Yemen for 90 days due to security concerns about terrorism. The next day, thousands of protesters gathered at airports and other locations throughout the United States to protest the signing of the order and detainment of the foreign nationals. Later, the administration reversed a part of the order to exempt visitors with a green card.
On May 3, 2017, Puerto Rico filed for bankruptcy after a massive debt and weak economy. It is the largest bankruptcy case in American history.
On September 24, 2019, Speaker of the House Nancy Pelosi announced that the House of Representatives would begin an impeachment inquiry into Trump. On October 31, 2019, the House voted 232–196 to created procedures for public hearings. On December 16, the House Judiciary Committee released a report specifying criminal bribery and wire fraud charges as part of the abuse of power charge. The house voted to impeach Trump on December 18, 2019, making him the third president in American history to be impeached. Trump was acquitted by a narrow 52-48 vote in the Senate. No conclusive evidence of any criminal wrongdoing has ever been found or produced concerning this impeachment.
During most of 2020, the United States was impacted by the COVID-19 pandemic that has impacted the world. The country became the highest infected from the pandemic and had the most people dead from the infection, although there is criticism concerning how the data was gathered. The Trump administration received negative responses for their handling of the virus, despite the very successful Operation Warp Speed that produces the first vaccine to fight the virus. Some people have refused to wear surgical masks to help stop the transmission of the virus. In some states, governors locked down their states in an attempt to stop the spreading of the virus.
In May 2020, racial tensions in the country began to intensify due to the police murder of George Floyd causing massive protests and rioting across the country. The Black Lives Matter movement began to grow in popularity, although it had a mixed reception.
On November 7, 2020, former vice president Joe Biden defeated President Trump in the country's presidential election with the highest voter turnout. At nearly 78 years old, Biden became the oldest person elected to the office and the first to be from the state of Delaware. Biden's running mate, U.S. senator Kamala Harris, was the first woman, African-American, and Asian-American to be elected Vice President. Harris became the highest-ranked elected official in the country.
On January 6, 2021, while members of the United States Congress met to certify Biden's electoral victory, alleged supporters of President Trump stormed into the United States Capitol attempting to overthrow the results of the 2020 election. Five people died. This led to the United States House of Representatives to impeach Trump for a second time, making him the only U.S. President to be impeached twice. Trump was again acquitted, with a 57-43 victory in the Senate.
Biden's Presidency
Joe Biden was inaugurated on January 20, 2021. At 78 years old, he replaced Donald Trump as the oldest person to be inaugurated as president and replaced Ronald Reagan as the oldest serving president.
U.S. troops withdrew from Afghanistan on August 31, 2021. The withdrawal coincided with the 2021 Taliban offensive, culminating in the fall of Kabul.
On June 24, 2022, the Supreme Court, in a landmark ruling, determined that abortion is not a protected right under the Consititution. The ruling, Dobbs v. Jackson Women's Health Organization, overturned Roe v. Wade and Planned Parenthood v. Casey. It sparked protests outside of the Supreme Court building and across the country.
Ketanji Brown Jackson succeeded Justice Stephen Breyer upon his retirement from the court on June 30, 2022. She became the first black woman and the first former federal public defender to serve on the Supreme Court upon her swearing in.
On November 15, 2022, Donald Trump announced that he was running for reelection to a second term in 2024, despite many then-ongoing legal troubles. Biden announced his run for reelection to a second term in April 25, 2023, despite having turned 80 the previous year. In early 2024, Trump and Biden handily won their respective parties' presidential primaries. On May 30, 2024, Trump became the first president to be found guilty of a felony and a crime in general.
On July 13, Trump was nearly assassinated at one of his rallies in Pennsylvania. After a poor debate performance on June 27, many Democrats called for Biden to leave the presidential race, which he did on July 21. He selected his running mate, Kamala Harris, to become the Democratic presidential nominee.
Trump won the election on November 5, becoming the second president to serve two terms that are not in a row, after Grover Cleveland (1885–1889, 1893–1897). At 78 years old, Trump once again became the oldest individual elected to the presidency, as well as the first criminal to be elected president.
 Second Trump presidency 
Trump was inaugurated for the second and final time on January 20, 2025. In the first three months of his presidency, Trump signed more than 100 executive orders, many of which are being challenged in court. Trump attempted to cut government spending by trying to shut down government services such as the United States Agency for International Development and the Department of Education.
 A changing country 
The United States faces many political issues. One of these is what kind of government the United States should become. Liberals want a large government, while the Tea Party and other groups want a smaller government. One of these debates is over health care. Health care costs have risen. Conservatives and liberals also disagree on social issues such as abortion and gay marriage. Many more people have come to accept gays and gay marriage as an acceptable part of American society. There are also many trends and developments that the U.S. must deal with. One of these is immigration. Many people are coming to the U.S. from Latin America and Asia, especially Mexico. This is called the "browning of America". Baby Boomer Americans are getting older and a larger fraction of the people are retired. Other issues facing the United States are a growing concern about the environment. This has led to the creation of many "green jobs", or jobs that create clean or renewable energy, often overlooking the negative effects that can occur from these initiatives, such as droughts caused by mining lithium for electric car batteries.


Evolution: Evolution is a biological process. It is how living things change over time and how new species develop. The theory of evolution explains how evolution works, and how living and extinct things have come to be the way they are. 
The theory of evolution is an essential idea in biology. Theodosius Dobzhansky, a well-known evolutionary biologist, said: "Nothing in biology makes sense except in the light of evolution".
Evolution has been happening since life started on Earth and is happening now. Evolution is caused mostly by natural selection. Living things are not identical to each other. Even living things of the same species look, move, and behave differently to some extent. Some differences make it easier for living things to survive and reproduce. 
Differences may make it easier to find food, hide from danger, or give birth to offspring which survive. The offspring will have some of the things which made it easier for their parents to have and raise them. Over time, these good differences continue and are spread through the population. Many generations pass and living things change enough to become new species.
Individuals who have differences that make it harder to find food, have offspring or avoid being eaten are likely not to have offspring at all and so will not be parents of future generations.
It is known that living things have changed over time, because their remains can be seen in the rocks. These remains are called 'fossils'. They prove that the animals and plants of today are different from those of long ago. The older the fossils, the bigger the differences from modern forms. Evolution is what made this happen. Evolution is a fact, and there is a lot of evidence that shows it is true. Scientists continue to study evolution to learn more about it.
Comparing DNA sequences helps scientists group living things based on how similar their DNA is. In 2010, a study compared DNA to family trees of evolution. This showed that all life comes from a common ancestor. Now, there is clear proof that life is connected through evolution.
 Evidence 
The evidence for evolution is given in a number of books. Some of this evidence is discussed here.
 Fossils show that change has occurred 
The realization that some rocks contain fossils was a very important event in natural history. There are three parts to this story:
1. The realization that things in rocks which looked organic actually were the altered remains of living things. This was settled in the 16th and 17th centuries by Conrad Gessner, Nicolaus Steno, Robert Hooke and others.
2. The realization that many fossils represented species which do not exist today. It was Georges Cuvier, the comparative anatomist, who proved that extinction occurred and that different strata contained different fossils.p108
3. The realization that early fossils were simpler organisms than later fossils. Also, the later the rocks, the more like the present day are the fossils.
"The most convincing evidence for the occurrence of evolution is the discovery of extinct organisms in older geological strata... The older the strata are...the more different the fossil will be from living representatives... that is to be expected if the fauna and flora of the earlier strata had gradually evolved into their descendants. Ernst Mayr p13
 Geographical distribution 
Where species live is a topic which fascinated both Charles Darwin and Alfred Russel Wallace. When new species occur, usually by the splitting of older species, this takes place in one place in the world. Once it is established, a new species may spread to some places and not others.
 Australasia 
Australasia has been separated from other continents for many millions of years. In the main part of the continent, Australia, 83% of mammals, 89% of reptiles, 90% of fish and insects, and 93% of amphibians are endemic. Its native mammals are mostly marsupials like kangaroos, bandicoots, and quolls. By contrast, marsupials are today totally absent from Africa and form a small portion of the mammalian fauna of South America, where opossums, shrew opossums, and the monito del monte occur (see the Great American Interchange).
The only living representatives of primitive egg-laying mammals (monotremes) are the echidnas and the platypus. They are only found in Australasia, which includes Tasmania, New Guinea, and Kangaroo Island. These monotremes are totally absent in the rest of the world. On the other hand, Australia is missing many groups of placental mammals that are common on other continents (carnivora, artiodactyls, shrews, squirrels, lagomorphs), although it does have indigenous bats and rodents, which arrived later.
The evolutionary story is that placental mammals evolved in Eurasia, and wiped out the marsupials and monotremes wherever they spread. They did not reach Australasia until more recently. That is the simple reason why Australia has most of the world's marsupials and all the world's monotremes.
 Evolution of horses 
The evolution of the horse family (Equidae) is a good example of the way that evolution works. The oldest fossil of a horse is about 52 million years old. It was a small animal with five toes on the front feet and four on the hind feet. At that time, there were more forests in the world than today. This horse lived in woodland, eating leaves, nuts and fruit with its simple teeth. It was only about as big as a fox.
About 30 million years ago the world started to become cooler and drier. Forests shrank; grassland expanded, and horses changed. They ate grass, they grew larger, and they ran faster because they had to escape faster predators. Because grass wears teeth out, horses with longer-lasting teeth had an advantage.
For most of this long period of time, there were a number of horse types (genera). Now only one genus exists: the modern horse, Equus. It has teeth which grow all its life, hooves on single toes, great long legs for running, and the animal is big and strong enough to survive in the open plain. Horses lived in western Canada until 12,000 years ago, but all horses in North America became extinct about 11,000 years ago. The causes of this extinction are not yet clear. Climate change and over-hunting by humans are suggested.
So, scientists can see that changes have happened. They have happened slowly over a long time. How these changes have come about is explained by the theory of evolution.
 Hawaiian Drosophila (fruit flies)
In about 6500 sqmi km2 on, the Hawaiian Islands have the most diverse collection of Drosophila flies in the world, living from rainforests to mountain meadows. About 800 Hawaiian fruit fly species are known.
Genetic evidence shows that all the native fruit fly species in Hawaii have descended from a single ancestral species that came to the islands, about 20 million years ago. Later adaptive radiation was caused by a lack of competition and a wide variety of vacant niches. Although it would be possible for a single pregnant female to colonise an island, it is more likely to have been a group from the same species.
 Distribution of Glossopteris 
The combination of continental drift and evolution can explain what is found in the fossil record. Glossopteris is an extinct species of seed fern plants from the Permian period on the ancient supercontinent of Gondwana.
Glossopteris fossils are found in Permian strata in southeast South America, southeast Africa, all of Madagascar, northern India, all of Australia, all of New Zealand, and scattered on the southern and northern edges of Antarctica.
During the Permian, these continents were connected as Gondwana. This is known from magnetic striping in the rocks, other fossil distributions, and glacial scratches pointing away from the temperate climate of the South Pole during the Permian.p103
 Common descent 
When biologists look at living things, they see that animals and plants belong to groups which have something in common. Charles Darwin explained that this followed naturally if "we admit the common parentage of allied forms, together with their modification through variation and natural selection".p402p456
For example, all insects are related. They share a basic body plan, whose development is controlled by master regulatory genes. They have six legs; they have hard parts on the outside of the body (an exoskeleton); they have eyes formed of many separate chambers, and so on. Biologists explain this with evolution. All insects are the descendants of a group of animals who lived a long time ago. They still keep the basic plan (six legs and so on) but the details change. They look different now because they changed in different ways: this is evolution.
It was Darwin who first suggested that all life on Earth had a single origin, and from that beginning "endless forms most beautiful and most wonderful have been, and are being, evolved".p490 Evidence from molecular biology in recent years has supported the idea that all life is related by common descent.
 Vestigial structures 
Strong evidence for common descent comes from vestigial structures.p397 The useless wings of flightless beetles are sealed under fused wing covers. This can be simply explained by their descent from ancestral beetles which had wings that worked.p49
Rudimentary body parts, those that are smaller and simpler in structure than corresponding parts in ancestral species, are called vestigial organs. Those organs are functional in the ancestral species but are now either nonfunctional or re-adapted to a new function. Examples are the pelvic girdles of whales, halteres (hind wings) of flies, wings of flightless birds, and the leaves of some xerophytes (e.g. cactus) and parasitic plants (e.g. dodder).
However, vestigial structures may have their original function replaced with another. For example, the halteres in flies help balance the insect while in flight, and the wings of ostriches are used in mating rituals and aggressive displays. The ear ossicles in mammals are former bones of the lower jaw.
"Rudimentary organs plainly declare their origin and meaning..." (p262). "Rudimentary organs... are the record of a former state of things, and have been retained solely through the powers of inheritance... far from being a difficulty, as they assuredly do on the old doctrine of creation, might even have been anticipated in accordance with the views here explained" (p402). Charles Darwin.
In 1893, Robert Wiedersheim published a book on human anatomy and its relevance to man's evolutionary history. This book contained a list of 86 human organs that he considered vestigial. This list included examples such as the appendix and the 3rd molar teeth (wisdom teeth).
The strong grip of a baby is another example. It is a vestigial reflex, a remnant of the past when pre-human babies clung to their mothers' hair as the mothers swung through the trees. Human babies' feet curl up when they are sitting down, while primate babies can grip with their feet as well. All primates except modern man have thick body hair which an infant can grasp, unlike modern humans. The grasp reflex allows the mother to escape danger by climbing a tree using both hands and feet.
Vestigial organs often have some selection against them. The original organs take resources to build and maintain. If they no longer have a function, reducing their size improves fitness. There is direct evidence of selection. Some cave crustacea reproduce more successfully with smaller eyes than do those with larger eyes. This may be because the nervous tissue dealing with sight now becomes available to handle other sensory input.p310
 Embryology 
From the eighteenth century, it was known that embryos of different species were much more similar than the adults. In particular, some parts of embryos reflect their evolutionary past. For example, the embryos of land vertebrates develop gill slits like fish embryos. Of course, this is only a temporary stage, which gives rise to many structures in the neck of reptiles, birds, and mammals. The proto-gill slits are part of a complicated system of development: that is why they persisted.
Another example is the embryonic teeth of baleen whales. They are later lost. The baleen filter is developed from different tissue, called keratin. Early fossil baleen whales did actually have teeth as well as the baleen.
A good example is the barnacle. It took many centuries before natural historians discovered that barnacles were crustacea. Their adults look so unlike other crustacea, but their larvae are very similar to those of other crustacea.
 Artificial selection 
Charles Darwin lived in a world where animal husbandry and domesticated crops were vitally important. In both cases, farmers selected individuals for breeding that had desirable characteristics and prevented the breeding of individuals with less desirable characteristics. The eighteenth and early nineteenth centuries saw growth in scientific agriculture. Some of that growth was due to artificial breeding.
Darwin discussed artificial selection as a model for natural selection in the 1859 first edition of his work On the Origin of Species, in Chapter IV: Natural selection: 
"Slow though the process of selection may be, if feeble man can do much by his powers of artificial selection, I can see no limit to the amount of change... which may be effected in the long course of time by nature's power of selection".p109
Nikolai Vavilov showed that rye, originally a weed, came to be a crop plant by unintentional selection. Rye is a tougher plant than wheat: it survives in harsher conditions. Having become a crop like wheat, rye was able to become a crop plant in harsh areas, such as hills and mountains.
There is no real difference in the genetic processes underlying artificial and natural selection, and the concept of artificial selection was used by Charles Darwin as an illustration of the wider process of natural selection. There are practical differences. Experimental studies of artificial selection show that "the rate of evolution in selection experiments is at least two orders of magnitude (that is 100 times) greater than any rate seen in nature or the fossil record".p157
 Artificial new species 
Some have thought that artificial selection could not produce new species. It now seems that it can.
New species have been created by domesticated animal husbandry, but the details are not known or not clear. For example, domestic sheep were created by hybridisation, and no longer produce viable offspring with Ovis orientalis, one species from which they are descended. Domestic cattle, on the other hand, can be considered the same species as several varieties of wild ox, gaur, yak, etc., as they readily produce fertile offspring with them.
The best-documented new species came from laboratory experiments in the late 1980s. William Rice and G.W. Salt bred fruit flies, Drosophila melanogaster, using a maze with three different choices of habitat such as light/dark and wet/dry. Each generation was put into the maze, and the groups of flies that came out of two of the eight exits were set apart to breed with each other in their respective groups.
After thirty-five generations, the two groups and their offspring were isolated reproductively because of their strong habitat preferences: they mated only within the areas they preferred, and so did not mate with flies that preferred the other areas.
Diane Dodd was also able to show how reproductive isolation can develop from mating preferences in Drosophila pseudoobscura fruit flies after only eight generations using different food types, starch, and maltose.
Dodd's experiment has been easy for others to repeat. It has also been done with other fruit flies and foods.
 Observable changes 
Some biologists say that evolution has happened when a trait that is caused by genetics becomes more or less common in a group of organisms. Others call it evolution when new species appear.
Changes can happen quickly in smaller, simpler organisms. For example, many bacteria that cause disease can no longer be killed with some antibiotic medicines. These medicines have only been in use since the 1940s, and at first, they worked extremely well. The bacteria have evolved so that they are less affected by antibiotics. The drugs killed off all the bacteria except a few which had some resistance. These few resistant bacteria reproduced, and their offspring had the same drug resistance.
The Colorado beetle is famous for its ability to resist pesticides. Over the last 50 years it has become resistant to 52 chemical compounds used in insecticides, including cyanide. This is natural selection sped up by artificial conditions. However, not every population is resistant to every chemical. The populations only become resistant to chemicals used in their area.
 History 
Although there were a number of natural historians in the 18th century who had some idea of evolution, the first well-formed ideas came in the 19th century. Four biologists are considered the most important.
 Lamarck 
Jean-Baptiste de Lamarck (1744–1829), a French biologist, claimed that animals changed according to natural laws. He said that animals could pass on traits they had acquired during their lifetime to their offspring, using inheritance. Today, his theory is known as Lamarckism. Its main purpose is to explain adaptations by natural means. He proposed a tendency for organisms to become more complex, moving up a ladder of progress, plus use and disuse.
Lamarck's idea was that a giraffe's neck grew longer because it tried to reach higher up. This idea failed because it conflicts with heredity (Mendel's work). Mendel made his discoveries about half a century after Lamarck's work.
 Darwin 
Charles Darwin (1809–1882) wrote his On the Origin of Species in 1859. In this book, he put forward much evidence that evolution had occurred. He also proposed natural selection as the way evolution had taken place. But Darwin did not understand genetics and how traits were actually passed on. He could not accurately explain what made children look like their parents.
Nevertheless, Darwin's explanation of evolution was fundamentally correct. In contrast to Lamarck, Darwin's idea was that the giraffe's neck became longer because those with longer necks survived better.p177/9 These survivors passed their genes on, and in time the whole species got longer necks.
 Wallace 
Alfred Russel Wallace OM FRS (1823–1913) was a British naturalist, explorer, biologist, and social activist. He proposed a theory of natural selection at about the same time as Darwin. His idea was published in 1858 together with Charles Darwin's idea.
 Mendel 
An Austrian monk called Gregor Mendel (1822–1884) bred plants. In the mid-19th century, he discovered how traits were passed on from one generation to the next.
He used peas for his experiments: some peas have white flowers and others have red ones. Some peas have green seeds and others have yellow seeds. Mendel used artificial pollination to breed the peas. His results are discussed further in Mendelian inheritance. Darwin thought that the inheritance from both parents blended together. Mendel proved that the genes from the two parents stay separate, and may be passed on unchanged to later generations.
Mendel published his results in a journal that was not well-known, and his discoveries were overlooked. Around 1900, his work was rediscovered. Genes are bits of information made of DNA which work like a set of instructions. A set of genes are in every living cell. Together, genes organise the way an egg develops into an adult. With mammals, and many other living things, a copy of each gene comes from the father and another copy from the mother. Some living organisms, including some plants, only have one parent, so get all their genes from them. These genes produce the genetic differences that evolution acts on.
 Darwin's theory 
Darwin's On the Origin of Species has two themes: the evidence for evolution, and his ideas on how evolution took place. This section deals with the second issue.
 Variation 
The first two chapters of the Origin deal with variations in domesticated plants and animals, and variations in nature.
All living things show variation. Every population which has been studied shows that animals and plants vary as much as humans do.p90 This is a great fact of nature, and without it evolution would not occur. Darwin said that, just as man selects what he wants in his farm animals, so in nature the variations allow natural selection to work.
The features of an individual are influenced by two things, heredity and environment. First, development is controlled by genes inherited from the parents. Second, living brings its own influences. Some things are entirely inherited, others partly, and some not inherited at all.
The colour of eyes is entirely inherited; they are a genetic trait. Height or weight is only partly inherited, and language is not at all inherited. The fact that humans can speak is inherited, but what language is spoken depends on where a person lives and what they are taught. Another example: a person inherits a brain of somewhat variable capacity. What happens after birth depends on many things such as home environment, education, and other experiences. When a person is an adult, their brain is what their inheritance and life experience have made it.
Evolution only concerns the traits which can be inherited, wholly or partly. The hereditary traits are passed on from one generation to the next through genes. A person's genes contain all the characteristics that they inherit from their parents. The accidents of life are not passed on. Each person lives a somewhat different life, which increases the differences.
Organisms in any population vary in reproductive success.p81 From the point of view of evolution, 'reproductive success' means the total number of offspring which live to breed and leave offspring themselves.
 Inherited variation 
Variation can only affect future generations if it is inherited. Because of the work of Gregor Mendel, we know that much variation is inherited. Mendel's 'factors' are now called genes. Research has shown that almost every individual in a sexually reproducing species is genetically unique.p204
Genetic variation is increased by gene mutations. DNA does not always reproduce exactly. Rare changes occur, and these changes can be inherited. Many changes in DNA cause faults; some are neutral or even advantageous. This gives rise to genetic variation, which is the seed corn of evolution. Sexual reproduction, by the crossing over of chromosomes during meiosis, spreads variation through the population. Other events, like natural selection and drift, reduce variation. A population in the wild always has variation, but the details are always changing.p90
 Natural selection 
Evolution mainly works by natural selection. What does this mean? Animals and plants which are best suited to their environment will, on average, survive better. There is a struggle for existence. Those who survive will reproduce and create the next generation. Their genes will be passed on, and the genes of those who did not reproduce will not. This is the basic mechanism which changes the characteristics of a population and causes evolution.
Natural selection explains why living organisms change over time, and explains the anatomy, functions, and behavior that they have. It works like this:
 All living things have such fertility that their population size could increase rapidly forever.
 However, population sizes do not increase forever. Mostly, population sizes remain about the same.
 Food and other resources are limited. Therefore, there is competition for food and resources.
 No two individuals are alike. Therefore, they will not have the same chances to live and reproduce.
 Much of this variation can be inherited. Parents pass traits to their children through their genes.
 The next generation can only come from those that survive and reproduce. After many generations of this, the population will have more helpful genetic differences, and fewer harmful ones. Natural selection is really a process of elimination.p117 The elimination is being caused by the relative fit between individuals and the environment they live in.
 Selection in natural populations 
There are now many cases where natural selection has been proved to occur in wild populations. Almost every case investigated of camouflage, mimicry and polymorphism has shown strong effects of selection.
The force of selection can be much stronger than was thought by the early population geneticists. The resistance to pesticides has grown quickly. Resistance to warfarin in Norway rats (Rattus norvegicus) grew rapidly because those that survived made up more and more of the population. Research showed that, in the absence of warfarin, the resistant homozygote was at a 54% disadvantage to the normal wild type homozygote.p182 This great disadvantage was quickly overcome by the selection for warfarin resistance.
Mammals normally cannot drink milk as adults, but humans are an exception. Milk is digested by the enzyme lactase, which switches off as mammals stop taking milk from their mothers. The human ability to drink milk during adult life is supported by a lactase mutation which prevents this switch-off. Human populations have a high proportion of this mutation wherever milk is important in the diet. The spread of this 'milk tolerance' is promoted by natural selection, because it helps people survive where milk is available. Genetic studies suggest that the oldest mutations causing lactase persistence only reached high levels in human populations in the last ten thousand years. Therefore, lactase persistence is often cited as an example of recent human evolution. As lactase persistence is genetic, but animal husbandry a cultural trait, that is gene–culture coevolution.
 Adaptation 
Adaptation is one of the basic phenomena of biology. Through the process of adaptation, an organism becomes better suited to its habitat.
Adaptation is one of the two main processes that explain the diverse species we see in biology. The other is speciation (species-splitting or cladogenesis). A favourite example used today to study the interplay of adaptation and speciation is the evolution of cichlid fish in African rivers and lakes.
When people speak about adaptation they often mean something which helps an animal or plant survive. One of the most widespread adaptations in animals is the evolution of the eye. Another example is the adaptation of modern horses' teeth to grinding grass. Camouflage is another adaptation; so is mimicry. The better-adapted animals are the most likely to survive and reproduce successfully (natural selection).
An internal parasite (such as a fluke) is a good example: it has a very simple bodily structure, but still the organism is highly adapted to its particular environment. From this we see that adaptation is not just a matter of visible traits: in such parasites, critical adaptations take place in the life cycle, which is often quite complex.
 Limitations 
Not all features of an organism are adaptations.p251 Adaptations tend to reflect the past life of a species. If a species has recently changed its life style, a once valuable adaptation may become useless, and eventually become a dwindling vestige.
Adaptations are never perfect. There are always tradeoffs between the various functions and structures in a body. It is the organism as a whole that lives and reproduces, therefore it is the complete set of adaptations that is passed on to future generations.
 Genetic drift and its effect 
In populations, there are forces that add variation to the population (such as mutation), and forces that remove it. Genetic drift is the name given to random changes which remove variation from a population. Genetic drift gets rid of variation at the rate of 1/(2N) where N = population size.p29 It is therefore "a very weak evolutionary force in large populations".p55
Genetic drift explains how random chance can affect evolution in surprisingly big ways, but only when populations are quite small. Overall, its action is to make the individuals more similar to each other, and hence more vulnerable to disease or to chance events in their environment.
 Drift reduces genetic variation in populations, potentially reducing a population’s ability to survive new selective pressures.
 Genetic drift acts faster and has more drastic results in smaller populations. Small populations usually become extinct.
 Genetic drift may contribute to speciation (starting a new species) if the small group does survive.
 Bottleneck events: when a large population is suddenly and drastically reduced in size by some event, the genetic variety will be very much reduced. Infections and extreme climate events are frequent causes. Occasionally, invasions by more competitive species can be devastating. ♦ In late 1800s, hunting reduced the Northern elephant seal to only about 20 individuals. Although the population has rebounded, its genetic variability is much less than that of the Southern elephant seal.♦ Cheetahs have very little variation. We think the species was reduced to a small number at some recent time. Because it lacks genetic variation, it is in danger of infectious diseases.
Founder events: these occur when a small group buds off from a larger population. The small group then lives separately from the main population. The human species is often quoted as having been through such stages. For example, when groups left Africa to set up elsewhere (see human evolution). Apparently, we have less variation than would be expected from our worldwide distribution. Groups that arrive on islands far from the mainland are also good examples. These groups, by virtue of their small size, cannot carry the full range of alleles to be found in the parent population.
 Species 
How species form is a major part of evolutionary biology. Darwin interpreted 'evolution' (a word he did not use at first) as being about speciation. That is why he called his famous book On the Origin of Species.
Darwin thought most species arose directly from pre-existing species. This is called anagenesis: new species by older species changing. Now we think most species arise by previous species splitting: cladogenesis.
 Species splitting 
Two groups that start the same can become very different if they live in different places. When a species gets split into two geographical regions, a process starts. Each adapts to its own situation. After a while, individuals from one group can no longer reproduce with the other group. Two separate species have evolved from one.
A German explorer, Moritz Wagner, during his three years in Algeria in the 1830s, studied flightless beetles. Each species is confined to a stretch of the north coast between rivers which descend from the Atlas mountains to the Mediterranean. As soon as one crosses a river, a different but closely related species appears. He wrote later:
"... a [new] species will only [arise] when a few individuals [cross] the limiting borders of their range... the formation of a new race will never succeed... without a long continued separation of the colonists from the other members of their species".
This was an early account of the importance of geographical separation. Another biologist who thought geographical separation was critical was Ernst Mayr.
One example of natural speciation is the three-spined stickleback, a sea fish that, after the last ice age, invaded freshwater, and set up colonies in isolated lakes and streams. Over about 10,000 generations, the sticklebacks show great differences, including variations in fins, changes in the number or size of their bony plates, variable jaw structure, and colour differences.
The wombats of Australia fall into two main groups, common wombats and hairy-nosed wombats. The two types look very similar, apart from the hairiness of their noses. However, they are adapted to different environments. Common wombats live in forested areas and eat mostly green food with lots of moisture. They often feed in the daytime. Hairy-nosed wombats live on hot dry plains where they eat dry grass with very little water or nutrition in it. Their metabolic rate is slow and they sleep most of the day underground.
When two groups that started the same become different enough, then they become two different species. Part of the theory of evolution is that all living things started the same, but then split into different groups over billions of years.
 Modern evolutionary synthesis 
This was an important movement in evolutionary biology, which started in the 1930s and finished in the 1950s. It has been updated regularly ever since.
The synthesis explains how the ideas of Charles Darwin fit with the discoveries of Gregor Mendel, who found out how we inherit our genes. The modern synthesis brought Darwin's idea up to date. It bridged the gap between different types of biologists: geneticists, naturalists, and palaeontologists.
When the theory of evolution was developed, it was not clear that natural selection and genetics worked together. But Ronald Fisher showed that natural selection would work to change species. Sewall Wright explained genetic drift in 1931.
Evolution and genetics: evolution can be explained by what we know about genetics, and what we see of animals and plants living in the wild.
Thinking in terms of populations, rather than individuals, is important. The genetic variety existing in natural populations is a key factor in evolution.
Evolution and fossils: the same factors which act today also acted in the past.
Gradualism: evolution is gradual, and usually takes place by small steps. There are some exceptions to this, notably polyploidy, especially in plants.
Natural selection: the struggle for existence of animals and plants in the wild causes natural selection. The strength of natural selection in the wild was greater than even Darwin expected.
Genetic drift can be important in small populations.
The rate of evolution can vary. There is very good evidence from fossils that different groups can evolve at different rates, and that different parts of an animal can evolve at different rates.p292, 397
 Some areas of research 
 Co-evolution 
Co-evolution is where the existence of one species is tightly bound up with the life of one or more other species.
New or 'improved' adaptations which occur in one species are often followed by the appearance and spread of related features in the other species. The life and death of living things is intimately connected, not just with the physical environment, but with the life of other species.
These relationships may continue for millions of years, as it has in the pollination of flowering plants by insects. The gut contents, wing structures, and mouthparts of fossilized beetles and flies suggest that they acted as early pollinators. The association between beetles and angiosperms during the Lower Cretaceous period led to parallel radiations of angiosperms and insects into the late Cretaceous. The evolution of nectaries in Upper Cretaceous flowers signals the beginning of the mutualism between hymenoptera and angiosperms.
 Tree of life 
Charles Darwin was the first to use this metaphor in biology. The evolutionary tree shows the relationships among various biological groups. It includes data from DNA, RNA and protein analysis. Tree of life work is a product of traditional comparative anatomy, and modern molecular evolution and molecular clock research.
The major figure in this work is Carl Woese, who defined the Archaea, the third domain (or kingdom) of life. Below is a simplified version of present-day understanding. 
 Macroevolution 
Macroevolution: the study of changes above the species level, and how they take place. The basic data for such a study are fossils (palaeontology) and the reconstruction of ancient environments. Some subjects whose study falls within the realm of macroevolution:
 Adaptive radiation, such as the Cambrian Explosion.
 Changes in biodiversity through time.
 Mass extinctions.
 Speciation and extinction rates.
 The debate between punctuated equilibrium and gradualism.
 The role of development in shaping evolution: heterochrony; hox genes.
 Origin of major categories: cleidoic egg; origin of birds.
It is a term of convenience: for most biologists it does not suggest any change in the process of evolution.p87 For some palaeontologists, what they see in the fossil record cannot be explained just by the gradualist evolutionary synthesis. They are in the minority.
 Altruism and group selection 
Altruism – the willingness of some to sacrifice themselves for others – is widespread in social animals. As explained above, the next generation can only come from those who survive and reproduce. Some biologists have thought that this meant altruism could not evolve by the normal process of selection. Instead a process called "group selection" was proposed. Group selection refers to the idea that alleles can become fixed or spread in a population because of the benefits they bestow on groups, regardless of the alleles' effect on the fitness of individuals within that group.
For several decades, critiques cast serious doubt on group selection as a major mechanism of evolution.
In simple cases it can be seen at once that traditional selection suffices. For example, if one sibling sacrifices itself for three siblings, the genetic disposition for the act will be increased. This is because siblings share on average 50% of their genetic inheritance, and the sacrificial act has led to greater representation of the genes in the next generation.
Altruism is now generally seen as emerging from standard selection. The warning note from Ernst Mayr, and the work of William Hamilton are both important to this discussion.
 Hamilton's equation 
Hamilton's equation describes whether or not a gene for altruistic behaviour will spread in a population. The gene will spread if rxb is greater than c:
where:
  is the reproductive cost to the altruist,
  is the reproductive benefit to the recipient of the altruistic behavior, and
  is the probability, above the population average, of the individuals sharing an altruistic gene – the "degree of relatedness".
 Sexual reproduction 
At first, sexual reproduction might seem to be at a disadvantage compared with asexual reproduction. In order to be advantageous, sexual reproduction (cross-fertilisation) has to overcome a two-fold disadvantage (takes two to reproduce) plus the difficulty of finding a mate. Why, then, is sex so nearly universal among eukaryotes? This is one of the oldest questions in biology.
The answer has been given since Darwin's time: because the sexual populations adapt better to changing circumstances. A recent laboratory experiment suggests this is indeed the correct explanation.
"When populations are outcrossed genetic recombination occurs between different parental genomes. This allows beneficial mutations to escape deleterious alleles on its original background, and to combine with other beneficial alleles that arise elsewhere in the population. In selfing populations, individuals are largely homozygous and recombination has no effect".
In the main experiment, nematode worms were divided into two groups. One group was entirely outcrossing, the other was entirely selfing. The groups were subjected to a rugged terrain and repeatedly subjected to a mutagen. After 50 generations, the selfing population showed a substantial decline in fitness (= survival), whereas the outcrossing population showed no decline. This is one of a number of studies that show sexuality to have real advantages over non-sexual types of reproduction.
 What evolution is used for today 
An important activity is artificial selection for domestication. This is when people choose which animals to breed from, based on their traits. Humans have used this for thousands of years to domesticate plants and animals.
More recently, it has become possible to use genetic engineering. New techniques such as 'gene targeting' are now available. The purpose of this is to insert new genes or knock out old genes from the genome of a plant or animal. A number of Nobel Prizes have already been awarded for this work.
However, the real purpose of studying evolution is to explain and help our understanding of biology. After all, it is the first good explanation of how living things came to be the way they are. That is a big achievement. The practical things come mostly from genetics, the science started by Gregor Mendel, and from molecular and cell biology.
 Evolution gems 
In 2010 the journal Nature selected 15 topics as 'Evolution gems'. These were:
 Gems from the fossil record 
Land-living ancestors of whales
From water to land (see tetrapod)
The origin of feathers (see origin of birds)
The evolutionary history of teeth
The origin of vertebrate skeleton
 Gems from habitats 
Natural selection in speciation
Natural selection in lizards
A case of co-adaptation
Differential dispersal in wild birds
Selective survival in wild guppies
Evolutionary history matters
 Gems from molecular processes 
Darwin's Galapagos finches
Microevolution meets macroevolution
Toxin resistance in snakes and clams
Variation versus stability
Nature is the oldest scientific weekly journal. The link downloads as a free text file, complete with references. The idea is to make the information available to teachers.
 Responses to the idea of evolution 
 Debates about the fact of evolution 
The idea that all life evolved had been proposed before Charles Darwin published On the Origin of species. Even today, some people still discuss the concept of evolution and what it means to them, their philosophy, and their religion. Evolution does explain some things about our human nature. People also talk about the social implications of evolution, for example in sociobiology.
Some people have the religious belief that life on Earth was created by a god. In order to fit in the idea of evolution with that belief, people have used ideas like guided evolution or theistic evolution. They say that evolution is real, but is being guided in some way.
There are many different concepts of theistic evolution. Many creationists believe that the creation myth found in their religion goes against the idea of evolution. As Darwin realised, the most controversial part of the evolutionary thought is what it means for human origins.
In some countries, especially in the United States, there is tension between people who accept the idea of evolution and those who do not accept it. The debate is mostly about whether evolution should be taught in schools, and in what way this should be done.
Other fields, like cosmology and earth science also do not match with the original writings of many religious texts. These ideas were once also fiercely opposed. Death for heresy was threatened to those who wrote against the idea that Earth was the center of the universe.
Evolutionary biology is a more recent idea. Certain religious groups oppose the idea of evolution more than other religious groups do. For instance, the Roman Catholic Church now has the following position on evolution: Pope Pius XII said in his encyclical Humani Generis published in the 1950s:
"The Church does not forbid that (...) research and discussions (..) take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter," Pope Pius XII Humani Generis
Pope John Paul II updated this position in 1996. He said that Evolution was "more than a hypothesis":
"In his encyclical Humani Generis, my predecessor Pius XII has already said that there is no conflict between evolution and the doctrine of the faith regarding man and his vocation. (...) Today, more than a half-century after (..) that encyclical, some new findings lead us toward the recognition of evolution as more than an hypothesis. In fact it is remarkable that this theory has had progressively greater influence on the spirit of researchers, following a series of discoveries in different scholarly disciplines," Pope John Paul II speaking to the Pontifical Academy of Science
The Anglican Communion also does not oppose the scientific account of evolution.
 Using evolution for other purposes 
Many of those who accepted evolution were not much interested in biology. They were interested in using the theory to support their own ideas on society.
 Racism 
Some people have tried to use evolution to support racism. People wanting to justify racism claimed that certain groups, such as black people, were inferior. In nature, some animals do survive better than others, and it does lead to animals better adapted to their circumstances. With humans groups from different parts of the world, all evolution can say is that each group is probably well suited to its original situation. Evolution makes no judgements about better or worse. It does not say that any human group is superior to any other.
 Eugenics 
The idea of eugenics was rather different. Two things had been noticed as far back as the 18th century. One was the great success of farmers in breeding cattle and crop plants. They did this by selecting which animals or plants would produce the next generation (artificial selection). The other observation was that lower class people had more children than upper-class people. If (and it's a big if) the higher classes were there on merit, then their lack of children was the exact reverse of what should be happening. Faster breeding in the lower classes would lead to the society getting worse.
The idea to improve the human species by selective breeding is called eugenics. The name was proposed by Francis Galton, a bright scientist who meant to do good. He said that the human stock (gene pool) should be improved by selective breeding policies. This would mean that those who were considered "good stock" would receive a reward if they reproduced. However, other people suggested that those considered "bad stock" would need to undergo compulsory sterilization, prenatal testing and birth control. The German Nazi government (1933–1945) used eugenics as a cover for their extreme racial policies, with dreadful results.
The problem with Galton's idea is how to decide which features to select. There are so many different skills people could have, you could not agree who was "good stock" and who was "bad stock". There was rather more agreement on who should not be breeding. Several countries passed laws for the compulsory sterilisation of unwelcome groups. Most of these laws were passed between 1900 and 1940. After World War II, disgust at what the Nazis had done squashed any more attempts at eugenics.
 Algorithm design 
Some equations can be solved using algorithms that simulate evolution. Evolutionary algorithms work like that.
 Social Darwinism 
Another example of using ideas about evolution to support social action is social Darwinism. Social Darwinism is a term given to the ideas of the 19th century social philosopher Herbert Spencer. Spencer believed the survival of the fittest could and should be applied to commerce and human societies as a whole.
Again, some people used these ideas to claim that racism, and ruthless economic policies were justified. Today, most biologists and philosophers say that the theory of evolution should not be applied to social policy.
 Controversy 
Some people disagree with the idea of evolution. They disagree with it for a number of reasons. Most often these reasons are influenced by or based on their religious beliefs instead of science. People who do not agree with evolution usually believe in creationism or intelligent design.
Despite this, evolution is one of the most successful theories in science. People have discovered it to be useful for different kinds of research. None of the other suggestions explain things, such as fossil records, as well. So, for almost all scientists, evolution is not in doubt.


Christianity: Christianity is a Abrahamic monotheistic world religion which is based on the life and teachings of Jesus, his crucifixion and death, and his resurrection. Many Christian churches, branches, and denominations believe and teach that Jesus was the messiah (Christ) and the Son of God – the Logos incarnation – who was sent by God, his father, to preach and teach the Gospel (the Good News) to the world and his followers, was arrested and executed by crucifixion on Good Friday for the sins and wrongdoings of humanity, physically resurrected from the dead two days later on Easter Sunday for the salvation of humanity and went to heaven to God, his father, and is in his kingdom, sitting on his right hand. Many Christian churches, branches, and denominations also believe and teach in his Second Coming, the belief that Jesus will one day return to the world, to judge us, and in the Trinity which teaches that there are three distinct persons in One God (i.e. God the Father, God (i.e. Jesus) the Son, and the Holy Spirit). Many Christians also pray using the trinity. Christianity is the world's largest and most widespread religion, and is followed by over 2.38 billion people worldwide, comprising around 28.8% of the entire world population. It's members and adherents known as Christians are estimated to make up a majority of the population in 157 countries, states, and territories worldwide. Christianity is culturally diverse in its Western Christian and Eastern Christian branches and churches, and also doctrinally diverse concerning justification and the nature of salvation and its attainment, ecclesiology, ordination, Christology (study of Christ), and Mariology (study of Mary, mother of Christ). The four canconical gospels of Matthew, Mark, Luke, and John – who are four of the twelve apostles of Jesus – are found in the New Testament of the Bible, and describe the life, ministry, and teachings of Jesus, as preserved in early Christianity, with the Old Testament of the Bible serving as the gospel's respected background for the coming of the messiah Jesus and his teachings. Christianity started as a minor religious sect of ancient Second Temple Judaism – with Hellenistic influences – founded in Judea around 30 AD, by Jesus and his followers, and developed and became a minor religion by the 2nd century AD, after Jesus's apostles, disciples, and followers spread the gospel and teachings of Jesus throughout the Roman Empire and later in areas outside the Roman Empire (such as in the Sassanian Empire, Britiain, Armenia, India, Eithiopia, and other kingdoms and areas), and converted many people to Christianity, despite the severe persecution, mass killings, and genocide of Christians for their faith and belief in Jesus by the Romans and others. Christianity became separated from the religion Judaism in the 2nd century AD and became it's own religion when many of the Gentiles who converted to Christianity refused to use or recognize any Jewish practices, beliefs, and customs. Although Christianity was illegal and strictly forbidden in the Roman Empire and in some other kingdoms such as India, the religion continued to grow and attract more followers from different areas – both inside and outside of the Roman Empire – despite many of the followers being severely persecuted by torture, mutilation, dismemberment, and murder horribly in the genocide against Christians in the Roman Empire. A lot of times, Christians who were captured by the Romans would be imprisoned, would be put in public places such as streets, festivals, theatres or arenas, where Roman audiences would gather to see Christians – including Christian adults and children – being horribly beaten, humiliated, tortured, mutilated, dismembered, and killed before the crowd. The torture and killings of Christians continued in the Roman Empire until the 4th century AD. Even though the Roman Emperor Constantine I, together with his co-emperor Licinius I, legalized Christianity by issuing the Edict of Milan in 313 AD, and banned Christians (and others from persecuted groups) from being tortured, mutilated, dismembered, and killed for their faith, and the Emperor Constantine himself converted to Christianity and followed Jesus, a lot of Christians in several provinces of the Eastern Roman Empire continued to be tortured and killed in the genocide until around 325 AD or so, especially by Roman authorities and soldiers, despite the tortures and killings being illegal and strictly forbidden. When the tortures and killings of Christians ended alltogether and the genocide stopped all together in almost all areas of the Roman Empire around 325 AD, with Emperor Constantine making the penalty for the crime of torturing and killings of Christians (or anybody else from a previously persecuted group) much harsher and enforcing the law harder, stating that all groups of people deserve to live unmolested and unpersecuted in peace. In the year, 325 AD, the First Council of Nicaea was convened in Niceaea and Christian bishops and priests from all over the Roman Empire came to meet and talk about the theology of Christianity. The priests and bishops wrote rules and theology of Christianity and the christology of Jesus that was agreed and decided on in the Nicene Creed and aldo adopted the Trinity (the idea of three distinct persons in One God] which was followed by mainstream Nicene Christianity. Most Christian churches, branches, and denominations who rejected the Trinity and the Nicene Creed followed Gnosticism, and became Gnostic denominations such as the Arians and Donatists for exmaple. Christianity was then consolidated in the Roman Empire and Emperor Theodosius I made Christianity the official state of religion of the Roman Empire in 381 AD, with the First Council of Constantinople. Nestorianism and the Oriental Orthodox churches both split into different Christian denominations and churches due to differences in their own theology and Christology in the 5th century AD, after the Council of Ephesus and the Council of Chalcedon, while the Catholic Church and Eastern Orthodoxy split in the Great Schism of 1054, with Eastern Orthodoxy being predominant in Eastern European and some Levantine countries and cultures and the Catholic Church being predominant in Western countries and cultures, while Protestantism split from the Catholic Church, during the Reformation Era in the 16th century, and split into numerous denominations, branches, and churches, while Restorationism split from Protestantism, when certain new sects, denominations, and churches with new beliefs and theology emerged, especially throughout the 19th and the 20th centuries such as the Mormon Church of Jesus Christ of Latter-day Saints and the Jehovah's Witnesses, and believed that the original teachings, practices, and beliefs of Jesus and his apostles, disciples, and followers were lost and/or misinterpreted, and required a restoration. During the early Middle Ages, Europe underwent a large Christianization process, with many cultures, tribes, and kingdoms being converted to Christianity. Christianity expanded worldwide due to missionary work, evangelism, colonization, immigration, and extensive trade, and split into numerous denominations, branches, and churches with their own theology, due to differences and reformations in theology and Christology. Christianity, especially the Catholic Church, played a extremely prominent role in the development of Western civilization during the Middle Ages, and has heavily influenced Western music, art, and culture.
The main branches of Christianity include: the Catholicism (around 1.3 billion followers), Protestantism (825 to 900 million followers), 
Jesus Christ: 
The most basic part of Christianity is the belief in Jesus as the Son of God and Messiah (Christ). The title "Messiah" comes from the Hebrew word he מָשִׁיחַ (māšiáħ) meaning anointed one. The Greek translation Χριστός (Christos) is the source of the English word "Christ". Jesus is English for the Hebrew word Yeshua. 
Christians believe that, as the Messiah, Jesus was anointed by God as ruler and savior of all people. Christians also believe that Jesus' coming was the fulfillment of prophecies of the Old Testament. The Christian belief of the Messiah is much different than the contemporary Jewish concept. The main Christian belief is that, through the death and resurrection of Jesus, sinful humans can be reconciled to God. Through this, they believe they are given salvation and eternal life.
There have been many theological disagreements over the nature of Jesus over the first centuries of Christian history. But Christians generally believe that Jesus is God incarnate and "true God and true man." Jesus, having become fully human, suffered the pain and temptations of a mortal man, but he did not sin. As fully God, he defeated death and came back to life again. According to the Bible, "God raised him from the dead," he ascended to heaven, is "seated at the right hand of the Father" and will return again to fulfill the rest of Messianic prophecy such as the Resurrection of the Dead, the Last Judgment, and the final creation of the Kingdom of God.
The Gospels of Matthew and Luke say that Jesus was conceived by the Holy Spirit and born from the Virgin Mary. Only a little of Jesus' childhood is written in the canonical gospels, but infancy gospels were popular in antiquity. However, the time of Jesus' adulthood the week before his death is written much about in the gospels. Some of the Biblical writings of Jesus' ministry are: his baptism, miracles, preaching, teaching, and deeds.
 Death and resurrection of Jesus 
Christians believe the resurrection of Jesus to be the main part of their faith (see 1 Corinthians 15) and the most important event in human history because it would show that Jesus has power over death and has the authority to give people eternal life. 
Among Christian beliefs, the death and resurrection of Jesus are two main events of Christian doctrine and theology. From what the New Testament says, Jesus was crucified, died a physical death, was buried in a tomb, and rose from the dead on the third day afterwards. Most Christians place his death on a Friday each year, which is the first day of his death. Saturday is the second day, and Sunday is the third day. The New Testament writes that after rising from the dead Jesus appeared many times before his Twelve Apostles and disciples. Once He appeared before "more than five hundred brethren at once". This was before Jesus' Ascension to heaven. Jesus' death and resurrection are remembered by Christians in their worship services, and most commonly during Holy Week, which has Good Friday and Easter Sunday in the week. The date for Holy Week changes from year to year as it is partially based on the Jewish lunar calendar. 
Salvation of Christ
Protestantism teaches that eternal salvation is a gift that is given to a person by God's grace. It is sometimes called "unmerited favor." This would mean that Salvation is God bringing humans into a right relationship with God through faith in Jesus Christ. It is the belief that one can be saved (rescued) from sin and the eternal death of hell. Many Protestants believe in the "assurance of salvation"—that God can put confidence in a believer that he has truly received salvation from Jesus Christ.
Catholicism teaches that although in most cases someone must be baptized a Catholic to be saved, it is sometimes possible for people who have not fully joined the Catholic Church to be saved. Catholics normally believe in the importance of "faith working through love" and sacraments in receiving salvation. The Catholic Church teaches that good works and piety, such as obedience to commands, taking the sacraments, going to church, doing penance giving alms, saying prayers, and other things, are important in becoming holy, but strongly emphasize that salvation is through God's grace alone, and all we can do is receive it.
Different denominations and traditions of Christianity believe in forms divine grace. Roman Catholicism and Eastern Orthodoxy teach the complete importance of the free will to work together with grace. Reformed theology teaches the importance of grace by teaching that a person is completely incapable of self-redemption, but the grace of God overcomes even the unwilling heart. Arminianism believes in a synergistic view, while Lutheran and most other Protestant denominations teach justification by grace through faith alone.
 Scriptures 
Christianity uses the Bible, a collection of many canonical books in two parts, the Old Testament and the New Testament. It is believed by Christians that they were written by people who were inspired by the Holy Spirit, and therefore it is most often believed to be the word of God. The Bible has been translated into over 600 languages. The translators are able to verify accuracy by using thousands of handwritten copies of the scriptures which are in the original languages of Hebrew Aramaic, and Greek.
 Creeds 
Creeds (from Latin credo meaning "I believe") are direct doctrinal statements or confessions, usually of religious beliefs. They started as formulas used when someone was baptised. During the Christological controversies of the 4th and 5th centuries they became statements of faith.
Some main Christian creeds are:
 The Apostles' Creed (Symbolum Apostolorum)
 The Nicene Creed
Many Christians accept the use of creeds, and often use at least one of the creeds given above. A smaller number of Protestants, notably Restorationists, a movement formed in the wake of the Second Great Awakening in the 19th century of the 19th century United States, oppose the use of creeds.
 Trinitarianism 
The Bible mentions God the Father, God the Son, and the Holy Spirit, which are three persons of the one True God. This idea, called Trinity, was developed at the First Council of Nicaea, in 325, and formalized during several church meetings or councils. Currently, many Christian churches are trinitarian. The Oriental Orthodox Churches agree with the ideas in the First Council of Nicaea, but they disagree with other councils.
Trinitarianism is the teaching that God is three different persons, or has three different relations, within One God; the Father, the Son (Jesus Christ), and the Holy Spirit. In the words of the Athanasian Creed, "the Father is God, the Son is God, and the Holy Spirit is God, and yet there are not three Gods but one God."
Trinitarianism is the group of Christians who believe in the doctrine of Trinity. Today, most Christian denominations and Churches believe this. Churches have different teachings about the trinitarian formula. Some say the Spirit comes only from the Father. Others say the Spirit comes both from the Father and the Son. This is known as filioque. Nontrinitarianism (also called Oneness) is the beliefs systems that reject the Trinity. Many different Nontrinitarian views, such as adoptionism or modalism, existed in early Christianity but were refuted by the majority of Christians, leading to the disputes about Christology.
An example of a more recent movement that claims the title of Christian but rejects trinitarianism is the Church of Jesus Christ of Latter-day Saints. The Latter-Day Saints started in the first half of the 19th century, in the United States. There are other smaller groups who also reject trinitarianism.
 The afterlife and end times 
Christians believe that human beings will receive judgement from God and are given either eternal life or eternal damnation. This includes the "Last Judgment" as well as the belief of a judgement particular to the soul after death.
There are also some differences among Christians in this belief. For example, in Roman Catholicism, those who die in a state of grace, go into purgatory, where they are cleansed before they can go into heaven.
Christians believe that at the second coming of Christ at the end of time, all who have died will be raised up from the dead for the Last Judgment, when Jesus will establish the Kingdom of God. There is also the belief of Universal Reconciliation. That is the belief that all people will someday be saved, and that hell is not forever. Christians who believe in this view are known as Universalists.
Christians have different ways to talk about the purpose of Jesus' coming: 
 to learn the best way to live and to follow his example
 to pay the price of sin in our lives by being the perfect sacrifice, without sin. (John 3:16)
 to tell people that their mistakes and sins will be forgiven and will be saved if they believe and have faith in the Lord Jesus and confess that they have sinned (1 John 1:9) (John 3:16) (Ephesians 1:7) (Romans 10:9)
 to display to people his immense power and why they should fear him.
 to teach people to forgive each other and repent of their own sin through grace. (Matthew 6:14)
 to "destroy the devil's work" (1 John 3 v 8)
 to help people share in his life through the gift of God's Spirit.
 Worship 
Worship is thought by most Christians to be a very important part of Christianity all through its history. Many Christian theologians have called humanity homo adorans, which means "worshiping ," and so the worship of God is at the very center of what it means to be human. This would mean that because God created all humanity, Christians should worship and give praise to God.
Most Christian worship has Scripture reading, talk about Scripture from a leader, singing, prayer together, and a small time for Church work. Christians may meet in special buildings, also called Churches, or outdoors, or at schools, or anywhere Christians feel they are needed.
The main worship service in Catholic Churches is the Mass and the main worship service in many Orthodox Churches is called the Divine Liturgy. In both of these Churches, along with the other parts of worship, the Eucharist or Communion is central. Here a priest by prayer asks God to change a small amount of bread and wine into what Catholics and Orthodox believe is Jesus's real body and blood, but without changing the accidents (appearance, taste, colour, etc.) of the bread and wine. Then the people each may receive a portion. Many Protestant churches have worship services similar to the Mass, some every week, others a few times a year. Some Protestants believe Jesus is really present at the Communion service, and some believe the bread and wine are symbols to help them remember what Jesus did
The Catholic Church has developed a short ceremony, Eucharistic Benediction, worshiping Jesus present in the Eucharist. They also may visit a Church building to pray in the presence of the Eucharist, Eucharistic Adoration.
The Orthodox and Catholic Churches spirituality place importance on the use of human senses such as sight and on the use of beautiful things. Catholic spirituality often involves the use of statues and other artistic representations, candles, incense, and other physical items as reminders or aids to prayer. The Orthodox Churches also use candles, incense, bells, and icons, but not statues. Orthodox and Catholic worship also makes use of movements, such as the Sign of the Cross, made by each person touching first the forehead, then chest, one shoulder, then the other shoulder. There is also bowing, kneeling, and prostration in Catholic and Orthodox worship.
 Sacraments 
In Catholic belief and practice, a sacrament is a religious symbol or often a rite which shows divine grace, blessing, or sanctity for the Christian who receives it. Examples of sacraments are Baptism and the Mass." The word is taken from the Latin word sacramentum, which was used to translate the Greek word for mystery.
The two most regularly used sacraments are Baptism and Eucharist (communion). Most Catholics use seven Sacraments: Baptism, the ritual immersion of a candidate to welcome them into the church; Confirmation, the sealing of the Covenant; the Eucharist, a ritual where consecrated bread (discs of unleavened, toasted bread) and wine representing Jesus' body and blood are consumed; Holy Orders, Reconciliation of a Penitent (confession), Anointing of the Sick, and Marriage. Some Christian denominations prefer to call them ordinances. These are the Orders from Christ to all believers found in the New Testament.
 Liturgical calendar 
Roman Catholics, Anglicans, Eastern Christians, and traditional Protestant groups center their worship around a liturgical calendar. Some events that are part of this calendar are the "holy days", such as solemnities which honor an event in the life of Jesus or the saints, times of fasting such as Lent, and other events, such as memoria. Christian groups that do not follow a liturgical tradition often keep some celebrations, such as Christmas, Easter,and Pentecost. A few churches do not use a liturgical calendar.
 Symbols 
These are some symbols that some denominations or individual churches may use:
 Alpha and Omega - The Greek letters Alpha and Omega are the first and last letters of the Greek alphabet. Alpha and Omega is a reference to God, who calls himself the "Alpha and Omega" (the first and the last letter of the Greek alphabet) in the Book of Revelation.
 Chi - The Greek letter Chi is the first letter of 'Christ' (Χριστός "Christos").
 Chi Rho - The Greek letters Chi and Rho are the first two letters of 'Christ' in Greek: Christos. Usually, the long stem of Rho (ρ) runs up and down through the cross of the Chi (χ).
 Christian cross - The cross is the most common symbol of Christianity. Christians believe that their savior Jesus Christ was crucified by the Romans. The cross is important because Jesus died as a sacrifice for the sins of believers. It represents God's love for humanity.
 Crucifix - The crucifix is a cross with the body of Jesus still hanging on it. It is a more popular symbol with Catholics and Eastern Orthodox. It has the same meaning as the cross.
 Dove - The dove is a bird and a symbol of the Holy Spirit. When Jesus was baptized, the Holy Spirit came to him in the form of a dove and rested on him.
 Ichthys - In Greek, the word ichthys /iktheews/ means 'fish', and forms an acronym, "Ίησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ", meaning "Jesus Christ, God's Son, Saviour" in Greek.
 Lamb - A lamb may be a symbol of Jesus himself, portrayed as the sacrifice for humans.
 Shepherd - A shepherd is also a symbol of Jesus himself and is used in the earliest Christian art. In the Bible, Jesus calls himself the good shepherd who cares for his sheep.
 INRI - INRI is an acronym in Latin "Iēsus Nazarēnus, Rēx Iūdaeōrum" meaning "Jesus the Nazarene, King of the Jews." This is the message that was put on the cross as being the crime for which he was being punished. Christians now use it as a symbol that Jesus is the Messiah, or King of all kings.
 Interlocking rings - Three interlocking rings are a symbol of the Trinity. Each ring is a complete circle, representing each complete person of the Trinity. But each ring is locked with the other two rings, showing that each divine person cannot be separated from the Trinity.
 History 
Christianity has had a large history from the time of Jesus and his apostles to the present time. Christianity began in the 1st century AD as a Jewish sect but quickly spread throughout the Greco-Roman world. Although it was originally persecuted under the Roman Empire, it later became the state religion. In the Middle Ages it spread into Northern Europe and Russia. During the Age of Exploration, Christianity expanded throughout the world, and is now the largest religion of the world.
The religion had schisms and theological disputes that had as result ten main branches or groupings: Catholicism, Eastern Orthodoxy, the Church of the East (Nestorianism), Oriental Orthodoxy (Miaphysitism), Lutheranism, the Reformed churches (Calvinism), Anglicanism, Anabaptism, Evangelicalism—these last five often grouped and labeled as Protestant—and Nontrinitarianism.
 Types of Christianity 
People who call themselves Christians may show or live their faith in different ways. They may also believe different things. Through history, the six main groups or "denominations" of Christianity have been:
 Catholic
 Protestant (including Anglican, Lutheran, Reformed, Anabaptist, Evangelical)
 Eastern Orthodox
 Oriental Orthodox (Miaphysite)
 Church of the East (Nestorian)
 Nontrinitarian (including Jehovah's Witnesses, Mormonism)
Not all Christians use these titles. Some believe Christianity is bigger and includes others. Some believe Christianity is smaller and does not include all these churches.
 Disagreements 
Some of these groups could not agree on certain points about Christian teaching (called “doctrine”) or practice. The first split was in the 5th century after the Church Council of Ephesus. The council agreed Nestorianism was wrong. The Assyrian Church of the East did not agree and split from the rest. The argument was about the nature of Jesus. Should he be regarded as God and human in one combined nature, or in two separate natures? Most of the bishops, following the Pope (the Bishop of Rome), refused to stay in communion with any bishop who would not say "two separate natures". This was also discussed at the Council of Chalcedon, about 20 years later. The Christians who did not agree with the decision of the Council to excommunicate them, became the non-Chalcedonian Orthodox. The largest Non-Chalcedonian Churches are the Coptic Orthodox in Egypt, the Ethiopian Orthodox, the Armenian, and some Lebanese Orthodox Churches. In general, these churches are known as Oriental Orthodox Churches. Recent discussions between the Roman Catholic Pope John Paul II and the Coptic Orthodox Pope Shenouda III concluded that they believe many of the same things after all, even though the Coptic Church does not recognize the Pope of Rome as its leader.
The third split happened in the 11th century. It is called the Great Schism. It was mostly based on the creed being translated incorrectly from Greek into Latin. The disagreements were made worse because the two cultures often did not understand one another. Also, many Crusaders from Western Europe behaved badly. The Christians in Western Europe were led by the Bishop of Rome, known also as the Pope. They are called the Catholic Church. Most Christians in Eastern Europe, Russia, the Middle East and South Asia, and northeast Africa belong to Orthodox, Nestorian, and Miaphysite Christianity, led by the Bishops of other cities or areas.
In the 15th century, the invention of the printing press made it easier for more people to read and study the Bible. This led many thinkers over the years to return to biblical ideas and to break away from the Catholic Church. They started the Protestant Reformation. The most important Protestant leaders were Jan Hus, Martin Luther, and John Calvin. Later some of these groups disagreed amongst themselves so that these denominations split again into smaller groups. The largest Protestant denominations today are within Evangelical, Lutheran, and Reformed Christianity. In England, a similar protest against the Pope, first political and later religious, led to the Church of England which has bishops and officially calls itself Reformed Catholic but is often referred to as Protestant. The Anglican communion of churches includes several churches called "Episcopal" or "Episcopalian" because they have bishops. Some Anglican Churches have a style of worship that is closer to the Protestant services, others worship more like Catholics, but none of them accept the Pope, or are accepted by him. The Anabaptists also arose from disagreements with Lutheran and Reformed Protestants during what is often called the Radical Reformation. The Evangelical churches arose in reaction to what they views as needs for reform within mainstream Protestantism. This can be seen in the rise of non-conformist movements against the Anglican church in Britain and during revivalist movements, prominently in the several Great Awakenings in Britain and North America. Denominations that arose or surged as a result of these Evangelical reform, renewal, and revival movements include Quakers, Baptists, Moravians, Methodists, the Restoration (Stone-Campbell) movement, Adventists, the Holiness movement, Pentecostals, the Fundamentalist movement, the Charismatic movement, Messianic Judaism, among others including many independent and non-denominational churches. In general, some Protestant denominations, especially within Anabaptism and Evangelicalism, differ from the Catholic, Orthodox, Nestorian, and Miaphysite churches in having given up some of the traditional sacraments, having no ordained priesthood, and not having the same fondness for Mary, the mother of Jesus, that the Catholic and Eastern churches have.
 Groups have different ideas on the nature of God.
 Groups have different ideas on the nature and work of the Holy Spirit in a believer's life.
 The pope is the leader of all Catholics. Other churches have leaders similar to the pope. For example, in the Eastern Orthodox Church, these are called Patriarchs. Still other groups let each church decide about things. 
 Some Christians say that women may not become priests or pastors.
 Some Christians say married people may not become priests.
 Some Christians say that priests can forgive sins by giving out the forgiveness of God, others say that only God can do this.
 In modern times, the rise of atheism and scientific challenges to the traditional Christian story of creation have caused some to believe in "Young Earth Creationism", or a literal interpretation of the first chapters of the Bible, and others to argue that those parts of the Bible are not literally true, but more like poetry.
 Most Christians worship on Sunday, but some believe that Saturday is the true "Sabbath" and should be kept.
 Some Christians believe that baptism must mean going fully under water, others put some water on the head.
 Some Christian groups baptize babies, while Baptists only baptize persons who have chosen for themselves to follow Jesus .
 Demographics 
With an estimated number of Christians being somewhere around 2.2 billion, split into around 34,000 different denominations, Christianity is the world's largest religion. The Christian share of the world's population has been around 33% for the last hundred years. This has caused Christianity to spread throughout the world, mainly in Europe and North America. It is still the main religion of Europe, the Americas, the Philippines, and Southern Africa. However it is becoming smaller in some areas, some of them are; Oceania (Australia and New Zealand), Northern Europe (with Great Britain, Scandinavia and other places), France, Germany, the Canadian provinces of Ontario, British Columbia, and Quebec, the Western and Northern parts of the United States, and parts of Asia (especially the Middle East, South Korea, Taiwan and Macau).
In most countries in the developed world, the number of people going to church who claim to be Christians has been dropping over the last few decades. Some believe that this is only because many no longer use regular membership in places, for example, churches, while others believe it is because people may be thinking that religion is no longer important.
 Ecumenism 
Most churches have for a long time showed that they want to be tolerant with other belief systems, and in the 20th century Christian ecumenism (the uniting of Christians from different backgrounds), advanced in two ways. One way was more cooperation between groups, such as the Edinburgh Missionary Conference of Protestants in 1910, the Justice, Peace and Creation Commission of the World Council of Churches started in 1948 by Protestant and Orthodox churches, and similar national councils, for example the National Council of Churches in Australia with Roman Catholics.
The other way was creating unions for different churches to join together. Congregationalist, Methodist, and Presbyterian churches joined together in 1925 to form the United Church of Canada, and in 1977 to form the Uniting Church in Australia. The Church of South India was formed in 1947 by the union of Anglican, Methodist, Congregationalist, Presbyterian, and Reformed churches. And other such formations have been done by different Christian groups throughout the years.


University of Cambridge: The University of Cambridge (also called Cambridge University) is in Cambridge, England. It is the second-oldest university in all English-speaking countries. It is one of the world's leading places of learning.
The University started as a group of scholars in the city of Cambridge. This may have started in 1209 when scholars left Oxford after a fight with local people. The universities of Oxford and Cambridge are often called Oxbridge. This is not a different university. It is a way of saying Oxford and Cambridge together. Cambridge University and Oxford University are both crucial to the history of England.
Cambridge is usually ranked in the world's top five universities. UK rankings and tests on the quality of its research also rate it very highly. Cambridge has more than 18,000 students and many sports clubs and societies.
Many important people studied at the University of Cambridge, including scientists, poets, artists, politicians and members of the British Royal Family. 121 former students and staff from Cambridge later won a Nobel Prize.
 History 
The official creation of the University was in 1231 when King Henry III of England gave people the right to teach students and lower taxes. A letter from Pope Gregory IX in 1233 also gave the right to everyone who got a degree from Cambridge to teach in any place in the Christian world.
In 1290, Pope Nicholas IV called Cambridge a studium generale (name for a university in Medieval times). From that point, many researchers and teachers from other European universities started to come to Cambridge to work or give lessons.
 Building the colleges 
Colleges started as places for students and teachers to live. They were called hostels at first. The students paid money to build and run these hostels. All colleges were formed after the beginning of the University. Over the years, colleges bought all of these hostels back. However, some old names still resist today, such as Garret Hostel Lane which was named after Garret Hostel.
Peterhouse was the first official college to be created in 1284. Many followed over the centuries and today there are 31. The last one, Robinson, was built in the 1970s. Many of these have a chapel because the members should have prayed for the soul of the founders (the people who created the college).
 The role of the University in the Protestant Reformation 
The University was one of the most important places where the Protestant Reformation began. The Protestant Reformation was a movement in Europe where people started disagreeing with certain teachings of the Catholic Church In fact, people started talking about Lutheranism - a type of Protestantism - very early in Cambridge. Thomas Cranmer, who became a central figure in reform, studied at Cambridge.
A century later, some people in Cambridge started to think that the Church of England was still too much like the Catholic church. They started the Puritan movement. This produced more than 20,000 people who left for New England around 1620 in search of a place with better religious beliefs. Oliver Cromwell, a very important member of this movement, was a student at Sidney Sussex College during this time.
 Mathematics and Physics 
Cambridge has been strong in applied mathematics since Isaac Newton was a student here in the 17th century. Every student had to study maths to obtain a degree. The degree was awarded as a Bachelor of Arts which mixed both arts and science subjects. Several important early physicists studied at Cambridge. They include James Clerk Maxwell, Lord Kelvin and Lord Rayleigh. Pure mathematics was slower to catch up, but Cambridge is still famous for it thanks to people like G.H. Hardy.
Six maths graduates from Cambridge won Fields Medals and one got an Abel Prize. These are the world's highest awards for mathematicians. Four other researchers at Cambridge also won Fields Medals.
 Important discoveries 
People at the University of Cambridge have made many important scientific discoveries. These are some of the best-known ones:
 Understanding the scientific method, by Francis Bacon
 The laws of motion and the development of calculus, by Sir Isaac Newton
 The development of the thermodynamics, by Lord Kelvin
 The discovery of the electron, by J. J. Thomson
 The splitting of the atom, by Ernest Rutherford and of the nucleus, by Sir John Cockcroft and Ernest Walton
 The unification of electromagnetism, by James Clerk Maxwell
 The discovery of hydrogen, by Henry Cavendish
 The theory of evolution by natural selection, by Charles Darwin
 A way of understanding natural selection with Mendelian genetics in a mathematical way, by Ronald Fisher
 The Turing machine, a basic model for computation, by Alan Turing
 The structure of DNA, by Francis Crick and James D. Watson 
 The development of quantum mechanics, by Paul Dirac
 The development of string theory, by Michael Green
 Women's education 
For many years only men were allowed to study at Cambridge. In 1869 Girton, the first college for women was built. Women could take exams from 1882, but only in 1948 did they start to be considered full members of the university. For a certain time, they even received ad eundem degrees (degrees from a University you have not studied at, but you deserve) from the University of Dublin.
Over the years, more women-only colleges were built, until in 1972 Churchill was the first one to become mixed. Many others followed, and in 1988 Magdalene was the last men-only college to open to women. However, there are still some colleges for women only. Cambridge is the only university that still has this characteristic. All other universities in the UK, including Oxford, now have only mixed colleges.
 Myths, legends and traditions 
Since it is very old, the University has many legends and traditions. These are often passed on by older students to the younger ones. Tour guides also tell these stories to tourists.
The wooden spoon tradition was to give this type of spoon to the student who was the worst in the year for mathematics but still passed the exams. This was because the students used to be ranked in order of their results. After 1909 this was changed and so the wooden spoon cannot be given anymore. However, still today in many sports competitions a wooden spoon is given to the last person in the rankings.
Many legends exist about places in Cambridge. For example, there is a story about the Mathematical Bridge in Queen's College. Newton built it without using any bolts or screws. Some people then took it down to see how it was made. When they tried to put it up again they could not do it, so they had to insert many bolts.
Another tradition is that the King's College choir sings the Nine Lessons and Carols church service. This is recorded by the BBC and sent around the world since 1928 by the radio. From 1954 it can also be seen on television. Many people watch it on Christmas Eve in Great Britain.
 Organisation 
The University of Cambridge is a "collegiate" university. This means it is divided into colleges, and every student and teacher joins one college only. Every one of these colleges has its property and money. They all have many Fellows who can teach all the subjects between them. Then there are Departments and Faculties, which are buildings where only one subject is studied. Some Schools bring different Departments and Faculties together. The overall head of the University is called the Vice-Chancellor. They are heads of the Senate and Regent House which make decisions for the whole University.
 Colleges 
There are 31 colleges in Cambridge:
 Christ's College (1505)
 Churchill College (1960)
 Clare College (1326)
 Clare Hall (1965) †
 Corpus Christi College (1352)
 Darwin College (1964) †
 Downing College (1800)
 Emmanuel College (1584)
 Fitzwilliam College (1966)
 Girton College (1869)
 Gonville and Caius College (1348)
 Homerton College (1976)
 Hughes Hall, Cambridge (1885) ‡
 Jesus College (1496)
 King's College (1441)
 Lucy Cavendish College (1965) * ‡
 Magdalene College (1428)
 Murray Edwards College (1954) *
 Newnham College (1871) *
 Pembroke College (1347)
 Peterhouse (1284)
 Queens' College (1448)
 Robinson College (1979)
 St Catharine's College (1473)
 St Edmund's College (1896) ‡
 St John's College (1511)
 Selwyn College (1882)
 Sidney Sussex College (1596)
 Trinity College (1546)
 Trinity Hall (1350)
 Wolfson College (1965) ‡
66%
- Only for women
†Only for Postgraduate students
‡Only for students older than 21
There are also 3 smaller affiliated colleges: Westcott House, Westminster College and Ridley Hall. These are not part of Cambridge University, but students there can follow the University's lessons. They are only for theology, the study of religion. These three colleges together form the Cambridge Theological Federation.
 Teaching 
The teaching is done through lectures and practical classes (where students do experiments in science subjects) organised by the Department. The colleges also organise supervision. These are small lessons in groups of 1 to 4: the students do some homework and then talk about it with a teacher. This is often considered one of the best things about studying at Cambridge. The teaching is very personal; students can ask questions and understand the subject.
 Schools, faculties and departments 
There are more than 150 different faculties and departments in Cambridge. These are then grouped into "Schools". These have a supervisory body, a group of people who check that the departments are doing ok. There are six Schools:
 Arts and Humanities
 Biological Sciences
 Clinical Medicine
 Humanities and Social Sciences
 Physical Sciences
 Technology
 Academic year 
The year is divided into three parts. The first one is Michaelmas Term, which is from October to December and takes its name from St Michael's day and Christmas. The second one is Lent Term which goes from January to March. The last one is Easter Term, from April to June. Within these times, there is 8 weeks called Full Term. Most lessons and exams happen in Full Term. All students need to live in college for this period. There is a University rule which says that students can get their degree only if they have stayed for at least 9 terms (3 years) at a distance of fewer than 10 miles from the main Church in Cambridge.
 Central administration 
 Chancellor and Vice-Chancellor 
The head of the University is the Chancellor. As of 2013, he is David Sainsbury. He was elected in 2011 after Prince Philip, Duke of Edinburgh said he did not want to do it anymore. Prince Philip had been Chancellor for 25 years. The position of Chancellor is mainly ceremonial. That means that the Chancellor does not take part in many decisions. He is just there because an overall head of the University is needed.
The Vice-Chancellor instead is the one that makes most decisions. For example, he/she approves and signs new rules. The role is given to a person for at least five years. The current Vice-Chancellor is Stephen J. Toope.
 Senate and Regent House 
The Senate House is a building in Cambridge. The degree ceremony takes place there. Any Cambridge student who has an MA degree is a member of the Senate. It is also the place where the important people in the University meet to take decisions. These important people are different Officers and Fellows of the colleges. They are also called the Regent House. This is not another building, it is just a way of calling these people. They can make and change rules when they meet. News and information are printed and given out in the Cambridge University Reporter. This is the official newspaper of the university.
 Finances 
The university had £7.1 billion in endowments in 2019. This money was given over lots of time by many people. This is the largest amount of money for any university in Europe. Every college controls its money on its own. They are all considered charitable organisations. The British Government also gives money to research grants: these are for postgraduate students and their teachers. There is also some income produced by Cambridge University Press.
In 2000, Cambridge received a very large donation of US$210 million from the Bill & Melinda Gates Foundation. This was to set up a scholarship so that US and other international students could study in Cambridge more easily. Bill Gates was also made a Knight by the Queen because of his generosity. Between 2005 and 2012, a campaign was made to get £1 billion from old students. This was at the same time as the University's 800th anniversary. The campaign got to the target early in 2010.
 Location 
 Sites 
The University is spread around the town of Cambridge. The older colleges are on the river Cam. The departments and faculties are spread in different places, usually grouped in sites. There are nine main sites:
66%
Addenbrooke's
Downing Site
Madingley/Girton
New Museums Site
Old Addenbroke's
Old Schools
Silver Street/Mill Lane
Sidgwick Site
West Cambridge
Addenbrooke's Hospital is where the medicine students go to learn how to cure patients. The Judge Business School is another important building: this is where courses about business and finance are taught. Since the different sites are quite close to each other, many students like to use bicycles to move around. A fifth of the journeys in the town is made by bike. Students are also not allowed to drive a car while they are in Cambridge.
 Town and Gown 
Local people from Cambridge don't always like the students. "Town and Gown" is a phrase to talk about this relationship. "Town" means the Cambridge locals while "Gown" means the students and teachers, from the type of dress they wear. Since the University began, there have been some fights between the two groups. In 1381, many things were stolen from the university and colleges. The Chancellor was then given extra power to control the order in the town. When the plague arrived in Cambridge in 1630, many colleges closed up. They did not want to help the locals who had the disease.
However, more recently there have been fewer fights. The University also means more jobs and money for the population. There are many small industries that were created in Cambridge because the University was near. This effect is called The Cambridge Phenomenon. Between 1960-2010 there have been 1,500 new companies and 40,000 new jobs in Cambridge just thanks to the University.
 Libraries and Museums 
The University has 114 libraries. The main one is called Cambridge University Library. It is a legal deposit, which means every book that is printed in the United Kingdom goes into this library. Many departments have their own library as well. They usually have special books for their subjects only. All colleges have a library. This is mainly for the undergraduates so that they can read basic books about their subjects. Some colleges also have very precious books and manuscripts. For example, the Parker Library (Corpus Christi College) has special books from Medieval times.
The university also has 8 museums and a botanical garden:
 Fitzwilliam Museum for art
 Kettle's Yard for contemporary art
 Museum of Archaeology and Anthropology, University of Cambridge for archaeological objects 
 Cambridge University Museum of Zoology for the study of animals
 Museum of Classical Archaeology
 Whipple Museum of the History of Science
 Sedgwick Museum of Earth Sciences for geology
 Scott Polar Research Institute that has a museum for the Arctic and Antarctic 
 Cambridge University Botanic Garden that was created in 1831
 University life 
 Research 
One of the main aims of the University of Cambridge is to do scientific research. All the departments are always studying and discovering new things. Many important people have done research in Cambridge. This is because the university has a lot of money and resources like laboratories and books. It had £283.7 M in 2011 to spend on research; this was mainly given by the UK Government and the European Commission.
 Admission 
Students need to pass some tests and Interviews to be allowed in Cambridge. For undergraduates, the application is done through UCAS. This is as with any other university in the UK. Students need to be very good to enter Cambridge. If they study A-levels, they are asked to get at least A*AA. Because many good students apply, the interview is very important to choose the best ones. These are done by Fellows. Usually about 25% of the applicants get a place. However, the number changes depending on the subjects. Some of them, like medicine and economics, are very hard to get into. Students need to choose a college before doing the application. They may later have to change it if the college thinks they are good but does not have enough places for them.
For postgraduates the application is different. They need to ask professors (teachers) in the departments they want to work in. After an interview, they can be given a place. They then have to get some funding (money to do the project). This can be given from a government or another institution.
 Access 
Some people think that admission to Cambridge is not very fair. This is because it is easier to get in if you go to a private school instead of a state school. In 2007-2008, only 57% of students who got a place were coming from a state school. However, about 93% of British children go to them. If a student goes to a private school, he/she is also more likely to get a place after the interview. In 2011, only 25% of students that applied from state schools got a place, while the percentage was 33% for private school students. The University is trying to make things better by making the admission process easier and giving scholarships for the poorer students. Another problem is that year after year there are also fewer people from state schools applying.
 Reputation and rankings 
Cambridge does very well when the quality of research is tested. In 2001, it was ranked first in the British Government Assessment Exercise. Cambridge also gives out more PhDs in a year than any other UK university.
The following table has Cambridge results over the years in various College and university rankings.
The colleges also have a ranking between them. This is called the Tompkins Table. It is published every year by The Independent newspaper. Trinity College and Emmanuel College usually do very well in it.
 Public examinations 
The University also runs many public examinations. This can be for people who want to take language tests in English for example. Some of the A-level and GCSEs exams are also written and organized here.
 Associations 
The University of Cambridge is a member of
 the Russell Group, a network of research-led British universities;
 the Coimbra Group, an association of leading European universities;
 the League of European Research Universities;
 the International Alliance of Research Universities.
It is also considered part of the "Golden Triangle", a geographical concentration of UK university research.
 Student life 
 Students' Union, JCR and MCR 
The Cambridge University Students' Union (CUSU) represents all the students within the University. All new students become members when they arrive in Cambridge. It was started in 1964 as the Students' Representative Council (SRC). There are six important positions in the Union which are taken by students who take a year off work. These people have meetings with the Vice-Chancellor and other university officers to talk about new rules or how to change them.
Inside the colleges, there are also groups of students who represent all of the others. These are called JCR (Junior Common Room) for undergraduates and MCR (Middle Common Room) for postgraduates. They organize things like Fresher's Week, the first week in October when new first-year students arrive. They also make sure every student is happy about his life in Cambridge.
 Sport 
Sport has always been very important in Cambridge. Many students try rowing because the Cam river is a good one to play this sport. There are many boat races between the different colleges. These are called bumps: because the river is too small, boats start one behind the other. To win, a boat needs to hit (or "bump") the one ahead. Every year in London there is also the famous Boat Race between Oxford and Cambridge. Many other sports are played between colleges and universities.
Places to do sports, like gyms and fields, are run by single colleges. A new University-wide sports complex is being built.
 Societies 
Cambridge is also full of societies: these are small groups of people that meet together to do something that they like. These can be speaking a language, playing chess, acting in theatres, or playing a musical instrument. In 2010, there were 751 societies. There can also be smaller clubs in the colleges.
 Newspapers and radio 
There are three students newspapers, that tell things that happen around the university. Varsity, created in 1947, is the oldest one. The Cambridge Student and The Tab are newer ones; The Tab has funny articles and is less serious. There is also a radio station called Cam FM. This is run with help from Anglia Ruskin University, which is another university in Cambridge.
 Formal Halls and May Balls 
Formal Halls are special dinners where students and Fellows eat together. Everyone wears a suit and there is good food. There is a prayer in Latin at the beginning and the end. These dinners are a tradition and the idea is that people in the college should get to know each other at them. After the exams, there is May Week when students make parties. A May Ball happens in every college: it lasts all night and there is lots of music and food.
 Important students 
Many people who later became very famous in their subject studied at Cambridge. 89 people linked with Cambridge have won a Nobel Prize. This includes 29 prizes in physics, 26 in medicine, 21 in chemistry and 9 in economics. People from Cambridge have also done great things in the arts and sports.
 Mathematics and sciences 
Cambridge has a very strong tradition in this field. Students include Isaac Newton, who made lots of experiments at Trinity College. Francis Bacon developed the Scientific method which is the starting point of today's science. G. H. Hardy and Srinivasa Ramanujan did a lot in pure mathematics. James Clerk Maxwell found out more about electromagnetism. In biology, Charles Darwin made his theory about natural selection while Francis Crick and James D. Watson discovered the structure of DNA. Also, David Attenborough, who is now a television presenter, was a science student at Cambridge.
In nuclear physics, the discoveries of Ernest Rutherford, Niels Bohr, J. J. Thomson and James Chadwick made people really understand what is inside an atom: electrons, protons and neutrons. J. Robert Oppenheimer studied here and later went on to develop the atomic bomb. In astronomy, Paul Dirac, Stephen Hawking, John Herschel and Georges Lemaître found out many things about the universe, from the Big Bang to black holes.
 Humanities, music and art 
Desiderius Erasmus was really important for starting studies about Greek and Latin at the University. In economics, John Maynard Keynes, Thomas Robert Malthus and Milton Friedman all started their theories in Cambridge. Known philosophers are Bertrand Russell, Ludwig Wittgenstein, George Santayana, Karl Popper and Muhammad Iqbal. Many Archbishops of Canterbury also studied at Cambridge, like Rowan Williams. William Wilberforce helped to stop the slave trade. Thomas Cranmer was an Archbishop who was then killed because of his ideas.
In music, Ralph Vaughan Williams, Charles Villiers Stanford, William Sterndale Bennett, Orlando Gibbons and more recently John Rutter all started their education at Cambridge. Some members of the band Radiohead were also here. In the arts, Quentin Blake was an undergraduate here.
 Literature 
Students in this field include Christopher Marlowe, writer of many tragedies; Samuel Pepys, after who the library in Magdalene College is called; William Makepeace Thackeray, famous for his satire; E. M. Forster, a more contemporary author and C. S. Lewis, fantasy writer. Virginia Woolf did not study here but based her books around the colleges. Poets include Edmund Spenser, John Donne, John Milton, John Dryden, Lord Byron and Samuel Taylor Coleridge who started the Romantic movement.
Known actors and directors are Ian McKellen, Derek Jacobi, Michael Redgrave, James Mason, Emma Thompson, Stephen Fry, Hugh Laurie, John Cleese, Eric Idle, Graham Chapman, Tilda Swinton, Thandie Newton, Rachel Weisz, Sacha Baron Cohen, Tom Hiddleston all studied at the university.
 Sports 
More than 50 people who won medals at the Olympic Games had studied in Cambridge, as George Mallory did, who might have been the first to reach the top of mount Everest.
 Politics 
Finally, Cambridge is also strong in politics because it educated:
15 British Prime Ministers, including Robert Walpole, thought to be the first Prime Minister of Great Britain.
At least 23 foreign Heads of Government, including the Prime Ministers of India, Singapore and Jordan.
At least 9 monarchs, HRH Charles, Prince of Wales and a large number of other royals.
3 people who signed of the United States Declaration of Independence.
Oliver Cromwell, Lord Protector of England (1653–58).
 Cambridge in books and popular culture 
Due to its long history, the University has been named in many books and works by different authors.
In Pride and Prejudice, some of the main characters studied at Cambridge
In Gulliver's Travels, the narrator starts from Emmanuel College
In A Tale of Two Cities, one of the characters is a professor in Cambridge
Sherlock Holmes has been an undergraduate at this University
Porterhouse Blue and Grantchester Grind are funny books about life in Cambridge as a student


Science tourism: November 2018
Science tourism is a travel topic grouping scientific attractions. It covers interests in visiting and exploring scientific landmarks, including museums, laboratories, observatories and universities.
Access
Many of the listed laboratories have ongoing scientific research, and may not be open to the general public, although they may offer occasional special public access opportunities. Observatories are usually open to the public and have tours showcasing their astronomical research.
Museums
Europe
Northern Europe
 Nobel Museum It has exhibitions about the Nobel Prize.
 Sweden Solar System in greater Stockholm, contains the world's largest scale model of the Solar System.
 Heureka in Vantaa is an interactive science museum, with different kinds of exhibitions about technology, physics, chemistry, medicine, astronomy and so on. Really exciting for children interested in science.
Central Europe
 Peenemünde – A place where the Germans developed some of the world's first rockets before and during WW2.
 Marie Curie Museum– History of radioactivity
 Auto & Technik Museum in Sinsheim, Baden-Württemberg (southwestern Germany). Has interesting displays of many vintage and historic cars, motorcycles, other machinery, and an extensive collection of aircraft, including a Soviet Tu 144 and French/Britain Concorde.
 Deutsches Museum – Probably the closest anybody is ever going to get to a "museum of everything" or at least a museum of "everything technology" and a whole lot more. One of the greatest scientific and technical museums in the world, it is one of the most important sights in the area and absolute "must see's" of Munich, visited by roughly 1.5 million visitors per year. Topics range from aviation to brewing, from computer sciences to bridge building. There are many guided tours on specific themes and in different languages. There is a planetarium and two branch offices in other locations, which show vehicles that found no place in downtown Munich.
 Zeppelin Museum in the city of Friedrichshafen offers a museum dedicated to zeppelins, and another to Dornier aircraft.
Western Europe
 Science Museum London
  Down House – In Kent, this is the home of Charles Darwin, preserved as a museum. Darwin worked out his theory of evolution by natural selection here. He wrote On the Origin of Species here. The house also has his garden, which was the basis of several of his later works. 
 James Clerk Maxwell's Birthplace and Museum – Edinburgh's answer to Newton and Einstein. His equations unified the forces of Electricity and Magnetism and paved the way for Einstein's theory of special relativity. Most modern electrical technology comes from the discoveries of James Clerk Maxwell
Southern Europe
 Leonardo da Vinci Museum of Science and Technology – Located in Milan. As the name tells, it is a museum to learn more about science and technology. Hosted in a former monastery, San Vittore al Corpo.
 South Tyrol Museum of Archaeology
Eastern Europe
 Memorial Museum of Astronautics in the outskirts of Moscow there are a couple of sites dedicated to the Soviet and Russian contributions to science and technology. These include the Memorial Museum of Astronautics, the All-Russia Exhibition Centre and the Monument to the Conquerors of Space. 
 Ostankino Tower – 540 m ft on high concrete transmission tower, Ostankino Tower.
 Akademgorodok – Out in the Siberian taiga near Novosibirsk, Akademgorodok (literally "academy town") was built during the Soviet era, so that the academic elite could conduct their research in relative freedom, prosperity, and isolation. The planned city with tree lined streets hosts several museums, institutes, as well as a beach on the Ob Sea, an artificial reservoir.
North America
 Exploratorium in San Francisco
 Kennedy Space Center in Cape Canaveral - The launch site for NASA's space missions. All 12 persons who have traveled to the Moon so far have started their journeys from here.
 National Air and Space Museum in Washington, D.C.
 National Museum of Mathematics or Momath in New York
 National Museum of Natural History in Washington, D.C.
 Space Center Houston in Webster, Texas - NASA space museum, plus tram tours of Johnson Space Center, including astronaut training facilities, Mission Control, and the actual Apollo and Mercury launch vehicles.
Oceania
 Powerhouse Museum – The Powerhouse Museum is a large museum, essentially of popular culture. It has displays on the history of fashion and transport, decorative arts, music, and space exploration exhibits. It also partly plays on a sci-tech theme, with interactive hands-on and discovery displays of technology, design and industry There is usually a special exhibition on as well. There are in-depth displays for all ages, but also displays especially created for young children to discover and play.
 Questacon – an interactive museum of science with exhibits illustrating scientific ideas from the principles of physics to the motion of an earthquake. Great for kids and excellent science books can be picked up here. Allow at least half a day.
South America
 Alcântara in Northeast Brazil, is the rocket launch site for the Brazilian Space Agency, and hosts a museum on the site
 Kourou in French Guiana hosts the Guyana Space Centre, the primary rocket launch site for the European Space Agency.
 Gold Museum in Bogotá, Colombia
 The Archeology Museum in Bogotá, Colombia
 Casa Marqués de San Jorge in Bogotá, Colombia
 Laboratories 
Europe
Many European countries participate on the European Organization for Nuclear Research, which has his laboratories including the famous Large Hadron Collider on the French/Swiss border. Plus the bigger European countries like France, Germany, Italy and UK operate national laboratories. Most laboratories have open days for public visits.
 Commissariat à l'énergie atomique et aux énergies alternatives – The CEA has 5 divisions: nuclear energy, technological research, life sciences, sciences of matter and military applications. It has one of the top 100 supercomputers in the world, the Tera-100.
 CEA Saclay – The biggest research center of the CEA hosts nuclear research reactors.
 CERN – the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. The Large Hadron Collider (LHC) is the world's largest experiment and most complex scientific accelerator. Founded in 1954, the CERN laboratory sits astride the Franco-Swiss border near Geneva. The weak force got discovered here in 1973 and in 1983 subsequently the W and Z bosons. In 1995 it created the first Anti-Hydrogen atoms of which the ASACUSA experiment can since 2014 produce a beam of. In 2012 the ATLAS and CMS experiment announced the discovery of a boson with 125 GeV, whose properties got confirmed to be the long-sought Higgs boson.
 Microcosm – In front of the entrance of the CERN laboratory there is a permanent exposition retracing its history.
 CERN Guided Tours – Both as individual or as group it is possible from time to time to visit the experiments.
 DESY (Hamburg)
 FAIR
 Gran Sasso
 National Physical Laboratory – the birthplace of atomic timekeeping. In the 1950s, Louis Essen and John Parry constructed the atomic clock, Caesium Mk. 1. This new clock kept time more accurately. It paved the way for redefining the second in 1967, based on the fundamental properties of CS atoms, rather than the quite irregular Earth rotation. The facilities in Teddington are among the world's most extensive and sophisticated for measurement science. On 20 May 2014, NPL Open House will give people the chance to explore much of the science that goes on at NPL and the facilities that are used to do it: NPL Open House 2014 https://web.archive.org/web/20140818025838/http://www.npl.co.uk/open-house/register/ 2014-08-18 . While children are allowed, the exhibits are aimed for adults, and children must be kept under adult supervision at all times.
 Rutherford Appleton Laboratory – a national scientific research laboratories in the UK operated by the Science and Technology Facilities Council. It is a multidisciplinary centre for research both in physical and life sciences. It had in 1957 a 50 MeV proton linear accelerator. RAL hosts ISIS, a spallation neutron source and the Central Laser Facility. RAL organises a monthly public scientific lecture: Talking Science.
North America
DOE Laboratories
In the United States of America overseen by the United States Department of Energy (DOE) the Office of science operates ten national laboratories. In total there are 17 national laboratories funded by the DOE. Most of the sites hold open houses where the public can come in for free and see how American tax dollars are invested in research. This used to include nuclear facilities, but those have been restricted since 9/11.
 Ames Laboratory – conducts research into various areas, including the synthesis and study of new materials, energy resources, high-speed computer design, and environmental cleanup and restoration. The Ames Project purpose was to produce high purity uranium to accompany the Manhattan Project. It's most notable faculty member Dan Shechtman won the 2011 Chemistry Nobel price. Contact the Lab in advance of your visit. Group tours can be arranged through the public affairs office.
 Argonne National Laboratory – founded in 1946 to carry out Enrico Fermi's work on nuclear reactors as part of the Manhattan Project. Today Argonne is a multidisciplinary science and engineering research center, to address vital national challenges in clean energy, environment, technology and national security. Argonne welcomes all members of the public age 16 or older to take guided tours of the scientific and engineering facilities and grounds. Tours last about two and a half hours and are by reservation only (call or email).
 Brookhaven National Laboratory – a multipurpose research institution funded primarily by the U.S. Department of Energy’s Office of Science. Located on the center of Long Island, New York, Brookhaven Lab operates large-scale facilities for studies in physics, chemistry, biology, medicine and applied science. It is the home of the Relativistic Heavy Ion Collider, which first observed/created the Quark-Gluon-Plasma. Brookhaven scientists won 7 Nobel prices including the Ribosome discovery (2009). The lab is open to the public on Sundays during the summer for tours and special programs.
 Fermi National Accelerator Laboratory – a US Department of Energy national laboratory specializing in high-energy particle physics. Hence many components of the Large Hadron Collider got engineered and tested here. The Top quark was discovered in 1995 by both the CDF and DØ experiments of the Tevatron accelerator at Fermilab. The 2008 Nobel price was given for the prediction of the third generation of quarks (Bottom and Top quarks). Fermilab visitors are allowed to visit two buildings on their own: the first and ground floor of Wilson Hall and the Lederman Science Center, Groups of six or more must book a visit by calling the Center.
 Lawrence Berkeley National Laboratory – founded in 1931 by Ernest Orlando Lawrence. 13 Nobel prizes have been awarded to LBNL scientists, the most recent one (2011) for the discovery of the accelerated expansion of the Universe. It started as a particle physics laboratory, became involved for the study of nuclear matter and discovered 16 chemical elements. It is today a multi-program research site. Visitors need special clearance or may take advantage of the open days. The site on top of the hill nicely overlooks the San Francisco Bay.
 Oak Ridge National Laboratory – a multiprogram science and energy laboratory, with scientific and technical capabilities spanning from basic to applied research. ORNL is famous to host the Titan supercomputer. The Spallation Neutron Source is an accelerator-based neutron source facility that provides the most intense pulsed neutron beams in the world for scientific research and industrial development. Oak Ridge National Laboratory hosts thousands of visitors every year. It is very important, if you are not a DOE or DOE contractor employee, to arrange your visit to ORNL ahead of time.
 Pacific Northwest National Laboratory – has many research projects for the U.S. Department of Homeland Security and the National Nuclear Security Administration. All PNNL visitors, regardless of nationality, will need to have visitor badges to go past the Lobby.
 Princeton Plasma Physics Laboratory – researches plasma physics and nuclear fusion science. PPPL is located on Princeton University's Forrestal Campus. The free tours are led by engineers and physicists who can answer questions about magnetic fusion. In order to visit email to request a tour and give PPPL two weekdays when you would like to visit and some background on your group, including where your group is from, how many people are in your group, the age-range and the educational background of your group.
 SLAC National Accelerator Laboratory – does experimental and theoretical research in elementary particle physics using electron beams and a broad program of research in atomic and solid-state physics, chemistry, biology, and medicine using synchrotron radiation. It discovered the charm quark, the quark structure inside the protons and neutrons and the tau lepton (3 Nobel prizes). At this time, all public and educational tours of the laboratory have been suspended. SLAC hopes to have them back and asks to check their website periodically for updates.
 Thomas Jefferson National Accelerator Facility – the Continuous Electron Beam Accelerator Facility, which is 1400m in length and accelerates electrons up to 6 GeV. The most powerful free-electron laser in the world has an output of over 14 kilowatts. The lab has an open house once a year that includes a tour of the accelerator tunnel and the free electron laser. No registration of visitors is required during the open house. The open house tours involve extended periods of walking, and many tour stops include stairs. Also, much of the event is outdoors.
Other Laboratories
 Biosphere 2 – designed as an artificially closed complete ecology, and was the setting for research on human interaction with natural systems. The site is now owned and maintained by the University of Arizona, which conducts tours for the public. Beware that the scientific credentials of the initial project phase is quite unclear as it started as theatre group. For example, no input was taken from the Antarctic research stations, where researcher experience extreme confinement.
Observatories
Observatory
Europe
 European Space Agency's Columbus Control Centre – used to control the Columbus research laboratory of the International Space Station, as well as a ground control centre for the Galileo satellite navigation system. It is located at a large research facility of the German Aerospace Centre. (DLR).
 Stjerneborg observatory on Hven Island, Sweden - Tycho Brahe's observatory.
 University Observatory Vienna – The Institute of Astronomy is part of the University of Vienna, located inside a fabulous historic building. The building and the Sternwartepark were closed for visitors up until recently. The park contains many rare trees. It has a mini observatory on the roof. Guided tours are available.
North America
 Mt Graham International Observatory – Operated by the University of Arizona, in the Pinaleño Mountains west of Safford, this observatory offers periodic tours for the public. Reservations required, preferably two or more weeks in advance. Tours depart from the Discovery Park Campus in Safford.
 Kitt Peak National Observatory – Operates several astronomical telescopes plus a large solar telescope. Several guided tours are available, as well as a nightly observation program (reservations required).
 McDonald Observatory
 Fred Lawrence Whipple Observatory – Call ahead for tour information.
 Lowell Observatory – Among other historical achievements, this is the observatory where Clyde Tombaugh discovered Pluto, and you can still see the telescope he used to do it.
 NRAO Very Large Array – Huge radio telescope array featured in numerous films and TV shows, still performing observations. Self-guided tour allows you to walk around the base of one of the dishes and see into the maintenance facility. Occasional guided tours (see website) give you a closer look.
 NRAO Green Bank Observatory – In a valley in the middle of the National Radio Quiet Zone in the West Virginia Mountains, ithis is the largest fully steerable single dish radio telescope in the world.
South America
While the headquarters of the European Southern Observatory are in Garching near Munich, Germany the observatories are in northern Chile.
 European Southern Observatory
 New Technology Telescope, La Silla, Chile
 Very Large Telescope, Paranal, Chile
 Atacama Large Millimeter Array/submillimeter Array, Llano de Chajnantor, Chile
 Africa 
 South Africa 
 Southern African Large Telescope – The SALT telescope is largest single optical telescope in the southern hemisphere and among the largest in the world.
 KAT-7, MeerKAT, PAPER, and SKA Africa – The SKA Telescope is the most powerful telescope ever conceived. Its precursor, MeerKAT, is already the most powerful telescope every built. Most of it is to be built in Africa under the auspices of SKA Africa. The African precursor, MeerKAT, is already the most powerful radio telescope every built. The core of the telescope is located near Carnarvon, on the Northern Cape, with more dishes in Botswana, Madagascar, Mozambique, Zambia, Namibia, Mauritius and Ghana.
 South African Astronomical Observatory – The national centre for optical and infrared astronomy in South Africa. The Observatory has a fascinating history dating back to 1820, which is when our main building was constructed, making it one of the oldest permanent structures in Cape Town. Owing to light and air pollution in the city, most of the actual observing happens in Sutherland in the Northern Cape, about 380 km from Cape Town. Some of the telescopes in Cape Town are still used for outreach and public events.
Namibia
 H.E.S.S. Telescope – One of the leading observatories studying very high energy (VHE) gamma-ray astrophysics.
Universities
The most prestigious universities generally attract excellent scientists and have fine science programs. University campuses are usually open to the public, though permission from guards is sometimes required, and there may be some café or cafeteria or mensa or restaurant or even a university shop on site. Universities usually offer public lectures about ongoing research. Otherwise, their seminars and buildings are reserved for the students and the working faculty including post-doctoral researchers or professors. On weekends or holidays, many universities require special permits to enter. Universities compete on a worldwide basis; hence, they are not ordered by geographical position or alphabetized. Below is a list of the 20 highest-ranked universities according to 2013/2014 QS world university ranking (of course rankings may differ according to year and specific subject).
 Massachusetts Institute of Technology – a private research university in Cambridge, Massachusetts.
 Harvard University – Established in 1636 in Cambridge, Massachusetts, Harvard is the oldest institution of higher education in the United States.
 University of Cambridge – a collegiate research university in Cambridge, England. It was founded in 1209 making it the world's third-oldest university. It includes 31 constituent colleges and academic departments which are organised into six Schools. 90 Nobel laureates count as affiliated.
 University College London – a public research university in London, England. It is based in the heart of London. It was founded in 1826. There are 27 Nobel Prize winners and three Fields Medallists amongst UCL's alumni and current and former staff.
 Imperial College London – a public research university in London, England specialised in science, engineering, medicine and business. The former constituent college of the federal University of London became independent in 2007. Imperial is locate in Central London. It lists currently 15 Nobel laureates and two Fields Medallists amongst Imperial's alumni and current and former faculty.
 University of Oxford – a collegiate research university in Oxford, England. Oxford publishes a leaflet Explore the University of Oxford, which contains a map and information on opening times of colleges, museums and other places of interest. The main places of interest are only a few minutes walk from the main rail and coach stations. Oxford open days in 2014 will be on the 2 July, 3 July and 19 September. Due to high demand, many colleges and some departments require advance booking for their events.
 Stanford University – a private research university in Stanford, California founded in 1885. 58 Nobel laureates have been affiliated with the university. The Stanford campus offers sightseeing and educational opportunities for tourists and first-time visitors. There are student led walking tours.
 Yale University – a private research university in New Haven, Connecticut. Fifty-one Nobel laureates have been affiliated with the University as students, faculty, or staff.
 University of Chicago – a private research university in Chicago, Illinois.
 California Institute of Technology – a private research university in Pasadena, California, United States. Caltech is a world-renowned research and education institution dedicated to advancing science and engineering. Tours are offered for prospective students on holidays or high school groups. Caltech also offers a self-guided walking tour with booklet.
 Princeton University – a private Ivy League research university in Princeton, New Jersey. It was founded in 1747.
 ETH Zürich – This Swiss Federal Institute of Technology is an engineering, science, technology, mathematics and management university. Twenty-one Nobel Prizes have been awarded to students or professors, the most famous of which is Albert Einstein in 1921. It is currently the top-ranked university in continental Europe.
 University of Pennsylvania
 Columbia University
 Cornell University
 Johns Hopkins University
 University of Edinburgh
 University of Toronto
 Ecole Polytechnique Fédérale de Lausanne
 King's College London (KCL)
Other
 Boltzmann's grave – The Boltzmann equation was originally formulated by Ludwig Boltzmann between 1872 and 1875. It relates the entropy S of an ideal gas to the quantity W, which is the number of microstates corresponding to a given macrostate. In the ideal gas limit it exactly corresponds to the proper thermodynamic entropy.
 Schwinger's grave – The first order correction to the fine structure constant (alpha) is engraved on Julian Schwinger's headstone at the Mt Auburn Cemetery.
 Schrödinger's grave – The Schrödinger equation is a partial differential equation that describes how the quantum state of some physical system evolves with time. It was formulated in late 1925. It is inscribed above his name on his grave site.
 Hofmeyr Skull, The Hofmeyr Skull is a specimen of a 36,000-year-old skull found in the 1950s near Hofmeyr, South Africa. The samples age supports the so-called "Out of Africa" theory that modern humans evolved from Africa.
 Groote Schuur Hospital, On December 3, 1967, 53-year-old Lewis Washkansky received the first human heart transplant at Groote Schuur Hospital in Cape Town, South Africa. The procedure was performed by Dr. Christiaan Barnard.


Mars: Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, nicknamed The Red Planet.
Mars is a terrestrial planet with caps of water and carbon dioxide. It has the largest volcano in the Solar System, and some very large impact craters.
Mars is named after the mythological Roman god of war because it appears of red color. Anything that has to do with Mars is called "Martian".
Space probes, such as the Viking program landers, are the main tools for the exploration of Mars.
 Appearance 
Mars is a terrestrial planet and made of rocks. The ground there is red because of iron oxide (rust) in the rocks and dust. The planet's atmosphere is very thin. It is mostly carbon dioxide with some argon and nitrogen and tiny amounts of other gases including oxygen. The temperatures on Mars are colder than on Earth, because it is farther away from the Sun and has less air to keep heat in. There is water ice and frozen carbon dioxide at the north and south poles. Mars does not have any liquid water on the surface now, but signs of run-off on the surface were probably caused by water.
The average thickness of the planet's crust is about 50 km (31 mi), with a maximum thickness of 125 km (78 mi).
 Moons 
Mars has two small moons, called Phobos and Deimos.
The origin of Mars' moons is unknown and controversial. One theory is that the moons are captured asteroids. However, the moons' near circular orbits and low inclination relative to the Martian equator are not in agreement with the capture hypothesis.
Estimates of the mass ejected by a large Borealis-size impact vary. Simulations suggest that a body about 0.02 of Mars mass (~0.002 Earth mass) in size can produce a sizable debris disk in Martian orbit. Much of the material would stay close to Mars. There are several other large impact basins on Mars that could also have ejected enough debris to form the moons.
 Physical geography 
 Lack of magnetic field 
Mars does not have a global magnetic field. Despite this, observations show that parts of the planet's crust have been magnetized. This suggests that polarity reversals have occurred in the past. This paleomagnetism is similar to the magnetic striping found on Earth's ocean floors. One theory is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo stopped working and the planet's magnetic field faded.
 Rotation and orbit 
A Martian day is called a sol, and is a little longer than an Earth day. Mars rotates in 24 hours and 37 minutes. It rotates on a tilted axis, just like the Earth does, so it has four different seasons. Of all the planets in the Solar System, the seasons of Mars are the most Earth-like, due to their similar axial tilt. The lengths of the Martian seasons are almost twice those of Earth's: Mars's greater distance from the Sun causes the Martian year to be almost two Earth years long.
Martian surface temperatures vary from lows of about −143 °C °F (at the winter polar caps) to highs of up to 35 °C °F (in equatorial summer). The wide range in temperatures is due mostly to the thin atmosphere which cannot store much solar heat. The planet is also 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight.
Its orbit is more eccentric than the Earth's (meaning less like a circle). Probably that is one reason why the Earth's climate varies so much. In other words, its orbit affects the climate of the Earth. That is just a theory at present.
 Water 
See main article, Water on Mars
A 2015 report says Martian dark streaks on the surface were affected by water.
Liquid water cannot exist on the surface of Mars due to its low atmospheric pressure (there is not enough air to hold it in), except at the lowest elevations for short periods. The two polar ice caps appear to be made largely of frozen water. The amount of ice in the south polar ice cap, if melted, would be enough to cover the entire planet's surface 11 meters deep. A permafrost mantle stretches from the pole to latitudes of about 60°.
Geological evidence gathered by unmanned missions suggest that Mars once had much liquid water on its surface. In 2005, radar data revealed the presence of large quantities of water ice at the poles, and at mid-latitudes. The Mars rover Spirit sampled chemical compounds containing water molecules in March 2007. The Phoenix lander found water ice in shallow Martian soil in July 2008.
Landforms seen on Mars strongly suggest that liquid water at some time existed on the planet's surface. Huge areas of ground have been scraped and eroded.
In August 2024, a reservoir of liquid water was discovered on Mars - deep in the rocky outer crust of the planet. The findings came from a new analysis of data from Nasa’s Mars Insight Lander, which recorded four years' of vibrations - Mars quakes - from deep inside the Red Planet.
 Polar caps 
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  Martian north polar cap.jpg 
  North polar early summer ice cap (1999)
  South Polar Cap of Mars during Martian South summer 2000.jpg
  South polar midsummer ice cap (2000)
Mars has two permanent polar ice caps. During a pole's winter, it lies in continuous darkness, chilling the surface and causing the deposition of 25–30% of the atmosphere into slabs of CO2 ice (dry ice). When the poles are again exposed to sunlight, the frozen CO2 sublimes (turns to vapor), creating enormous winds that sweep off the poles as fast as 400 km/h. Each season this moves large amounts of dust and water vapor, giving rise to Earth-like frost and large cirrus clouds and dust storms. Clouds of water-ice were photographed by the Opportunity rover in 2004.
The polar caps at both poles consist primarily of water ice.
 Atmosphere 
Mars has a very thin atmosphere with barely any oxygen (it is mostly carbon dioxide). Because there is an atmosphere, however thin it is, the sky changes colour when the sun rises and sets. The dust in the Martian atmosphere makes Martian sunsets somewhat blue. Mars's atmosphere is too thin to protect Mars from meteors, which is part of the reason why Mars has so many craters.
 Meteorite craters 
After the formation of the planets, they all experienced the "Late Heavy Bombardment". About 60% of the surface of Mars shows a record of impacts from that era. Much of the remaining surface is probably lying over the immense impact basins caused by those events. There is evidence of an enormous impact basin in the northern hemisphere of Mars, spanning 10600 by 8500 km mi on, or roughly four times larger than the largest impact basin previously known. This suggests that Mars was struck by a Pluto-sized body about four billion years ago. The event is thought to be the cause of the difference between the Martian hemispheres. It made the smooth Borealis Basin that covers 40% of the planet.
Some meteorites hit Mars with so much force a few pieces of Mars went flying into space even to Earth. Rocks on Earth are sometimes found which have chemicals that are exactly like the ones in Martian rocks. These rocks also look like they fell really quickly through the atmosphere, so it is reasonable to think they came from Mars.
 Recent hits 
Spacecraft Insight detected seismic waves made by the biggest meteorite impacts ever seen on Mars.
 Geography 
Mars is home to the highest known mountain in the Solar System, Olympus Mons. Olympus Mons is about 17 miles (or 27 kilometers) high. This is more than three times the height of Earth's tallest mountain, Mount Everest. It is also home to Valles Marineris, the third largest rift system (canyon) in the Solar System, 4,000 km long.
 Observation of Mars 
Our records of watching and recording Mars start with ancient Egyptian astronomers in the 2nd millennium BC.
Detailed observations of the location of Mars were made by Babylonian astronomers who developed methods using math to predict the future position of the planet. The ancient Greek philosophers and astronomers developed a model of the solar system with the Earth at the center ('geocentric'), instead of the sun. They used this model to explain the planet's motions. Vedic and Islamic astronomers estimated the size of Mars and its distance from Earth. Similar work was done by Chinese astronomers.
In the 16th century, Nicholas Copernicus proposed a model for the Solar System in which the planets follow circular orbits about the Sun. This 'heliocentric' model was the beginning of modern astronomy. It was revised by Johannes Kepler, who gave an elliptical orbit for Mars which better fit the data from our observations.
The first observations of Mars by telescope was by Galileo Galilei in 1610. Within a century, astronomers discovered distinct albedo features (changes in brightness) on the planet, including the dark patch and polar ice caps. They were able to find the planet's day (rotation period) and axial tilt.
Better telescopes developed early in the 19th century allowed permanent Martian albedo features to be mapped in detail. The first crude map of Mars was published in 1840, followed by better maps from 1877 onward. Astronomers mistakenly thought they had detected the spectroscopic mark of water in the Martian atmosphere, and the idea of life on Mars became popular among the public.
Yellow clouds on Mars have been observed since the 1870s, which were windblown sand or dust. During the 1920s, the range of Martian surface temperature was measured; it ranged from 85 to 7 oC. The planetary atmosphere was found to be arid with only traces of oxygen and water. In 1947, Gerard Kuiper showed that the thin Martian atmosphere contained extensive carbon dioxide; roughly double the quantity found in Earth's atmosphere. The first standard naming of Mars surface features was set in 1960 by the International Astronomical Union.
Since the 1960s, multiple robotic spacecraft and rovers have been sent to explore Mars from orbit and the surface. The planet has remained under observation by ground and space-based instruments across a broad range of the electromagnetic spectrum (visible light, infrared and others). The discovery of meteorites on Earth that came from Mars has allowed laboratory examination of the chemical conditions on the planet.
 Martian 'canals' 
During the 1877 opposition, Italian astronomer Giovanni Schiaparelli in Milan used a 22 cm on telescope to help produce the first detailed map of Mars. What caught people's attention was that the maps had features he called canali. These were later shown to be an optical illusion (not real). These canali were supposedly long straight lines on the surface of Mars to which he gave names of famous rivers on Earth. His term canali was popularly mistranslated in English as canals, and thought to be made by intelligent beings.
Other astronomers thought they could see the canals too, especially the American astronomer Percival Lowell who drew maps of an artificial network of canals on Mars.
Although these results were widely accepted, they were contested. Greek astronomer Eugène M. Antoniadi and English naturalist Alfred Russel Wallace were against the idea; Wallace was extremely outspoken. As bigger and better telescopes were used, fewer long, straight canali were observed. During an observation in 1909 by Flammarion with a 84 cm in on telescope, irregular patterns were observed, but no canali were seen.
 Search for life 
Because Mars is the one of the closest planets to Earth in the Solar System, many have wondered if there is any kind of life on Mars. Scientists have not found life on Mars (as of 2024). No sign of former life, has been found. 
Today we know that this life, if any, would be simple organisms, like bacteria.
 Meteorites 
NASA maintains a catalog of 34 Mars meteorites, that is, meteorites which originally came from Mars. These assets are highly valuable since they are the only physical samples available of Mars.
Studies at NASA's Johnson Space Center show that at least three of the meteorites contain possible evidence of past life on Mars, in the form of microscopic structures resembling fossilized bacteria (so-called biomorphs). Although the scientific evidence collected is reliable, and the rocks are correctly described, what made the rocks look like they do is not clear. To date, scientists are still trying to agree if it really is evidence of simple life on Mars.
Over the past few decades, scientists have agreed that when using meteorites from other planets found on Earth (or rocks brought back to Earth), various things are needed to be sure of life. Those things include:
 Whether the rock comes from the right time and place on the planet for life to exist.
 Whether samples contain evidence of bacterial cells (if they show fossils of some kind, even if very tiny).
 Whether there is any evidence of biominerals (minerals usually caused by living things).
 Whether there is any evidence of isotopes typical of life.
 Whether the features are part of the meteorite, and not contamination from Earth.
For people to agree on past life in a geologic sample, most or all of these things must be met. This has not happened yet, but investigations are still in progress. Reexaminations of the biomorphs found in the three Martian meteorites are underway.
 The significance of water 
Liquid water is necessary for life and metabolism, so if water was present on Mars, the chances of life evolving is improved. The Viking orbiters found evidence of possible river valleys in many areas, erosion and, in the southern hemisphere, branched streams. Since then, rovers and orbiters have also looked closely and eventually proved water was on the surface at one time, and is still found as ice in the polar ice caps and underground.
 As of 2024
Several space probes have gone to Mars to study it. Some have orbited (gone around) the planet, and some have landed on it. There are pictures of the surface of Mars that were sent back to Earth by the probes.
The Cheyava Falls rock was discovered on Mars in June 2024. NASA gave it a designation, as a "potential biosignature". The rock was core sampled by the Perseverance rover for possible return to Earth and further examination. Research has not shown (as of 2024) if the rock has a biological origin or abiotic origin.
The most recent probe to the planet is the Mars Science Laboratory. It landed on Aeolis Palus in Gale Crater on Mars on 6 August 2012. It brought with it a mobile explorer called 'Curiosity'. It is the most advanced space probe ever. Curiosity has dug up Martian soil and studied it in its laboratory. It has found sulfur, chlorine, and water molecules.
Some people are interested in sending astronauts to visit Mars. They could do a better search, but getting astronauts there would be difficult and expensive. The astronauts would be in space for many years, and it could be very dangerous because of radiation from the Sun. So far we have only sent unmanned probes.
 Popular culture 
Some famous stories were written about the idea of life on Mars. The writers used the name "Martians" for intelligent beings from Mars. In 1898, H.G. Wells wrote The War of the Worlds'', a famous novel about Martians attacking the Earth. In 1938, Orson Welles broadcast a radio version of this story in the United States, and many people thought it was really happening and were very scared. Beginning in 1912, Edgar Rice Burroughs wrote several novels about adventures on Mars.


Indian rupee: The Indian rupee (रुपया) (sign: ; code: INR) is the official currency of the Republic of India. The currency is issued and controlled by the Reserve Bank of India. During the past 15 years, the value has ranged from $1 USD = 0.01 INR or 1 euro = 0.01 INR (see below: Convertibility).
The modern rupee is sub-divided into 100 paise (singular paisa). The coins have values and of 5, 10, 20, 25 and 50 paise, as well as 1, 2, 5 and 10 rupees. The bank notes are available in values of 1, 2, 5, 10, 20, 50, 100, 200, 500 and 2000 rupees.
The Indian rupee symbol () is an amalgam of both the Devanagari consonant "र" (Ra). The design was presented to the public by the government of India on 15 July 2010.
The current abbreviation "INR" started in July 2010. Until then, the abbreviation "Rs" (or "Re") was used.
 Origin of name 
The word "rupee" originates from the Sanskrit word रौप्य(raupya) meaning "silver" or "made of silver". Many Indian languages use this root word, for example, రూపాయి (rūpāyi) in Telugu, ரூபாய் (rūbāi) in Tamil, रुपया (rupayā) in Hindi, રૂપિયો (rupiyo) in Gujarati, ರೂಪಾಯಿ (rūpāyi) in Kannada and Tulu, രൂപ (rūpā) in Malayalam and रुपये (rupaye) in Marathi.
However, in West Bengal, Tripura, Mizoram, Odisha, and Assam, the Indian rupee is officially known by names derived from the Sanskrit word टङ्क (Tanka) which means money. The rupee is called টাকা (Taka) in Bengali, টকা (tôka) in Assamese and ଟଙ୍କା (Tanka) in Odia and is written as such on Indian banknotes.
 Symbol 
On March 5, 2009, the Government of India announced a contest to create a symbol for the rupee. During the 2010 Union budget of India, Finance Minister Pranab Mukherjee mentioned that the proposed symbol would reflect and capture the Indian ethos and culture. Five symbols were shortlisted, and the Cabinet selected the definitive symbol created by D. Udaya Kumar on July 15, 2010. The symbol is derived from a combination of the Devanagari letter ‘र’ and English letter ‘R’. The parallel lines at the top (with white space between them) make an allusion to the tricolor and also depict an equality sign which symbolizes the nation's desire to reduce economic disparity. The Indian government has plans to adopt the symbol within six months in the country and globally within 18 to 24 months. Before the adoption of the symbol, the most commonly used symbols for the rupee were Rs, Re or if the text was in an Indian language, then an appropriate abbreviation in that language.
 Numeral system 
In Indian English, values at or above a hundred thousand Indian rupees are counted in terms of lakhs (one lakh = hundred thousand) and crores (one crore = ten million). For example, the amount 3,25,84,729.25 is read as three crores, twenty-five lakhs, eighty-four thousand, seven hundred and twenty-nine rupees and twenty-five paise. The use of million or billion, as is standard in American or British English, is not very common.
 History 
 Use in India 
India was one of the earliest issuers of coins (circa 6th century BC). The first "rupee" is believed to have been introduced by Sher Shah Suri (1486–1545), based on a ratio of 40 copper pieces (paisa) per rupee. Among the earliest issues of paper rupees were those by the Bank of Hindustan (1770–1832), the General Bank of Bengal and Bihar (1773–75, established by Warren Hastings) and the Bengal Bank (1784–91), amongst others. Until 1815, the Madras Presidency also issued a currency based on the fanam, with 12 fanams equal to the rupee.
Historically, the rupee, derived from the Sanskrit word raupya, which means silver, was a silver coin. This had severe consequences in the nineteenth century, when the strongest economies in the world were on the gold standard. The discovery of vast quantities of silver in the U.S. and various European colonies resulted in a decline in the relative value of silver to gold. Suddenly the standard currency of India could not buy as much from the outside world. This event was known as "the fall of the rupee".
India was not affected by the imperial order-in-council of 1825 that attempted to introduce the British sterling coinage to the British colonies. British India at that time was controlled by the British East India Company. The silver rupee continued as the currency of India throughout the entire period of the British Raj and beyond. In 1835, British India set itself firmly upon a mono-metallic silver standard based on the rupee. His decision was influenced by a letter, written in the year 1805, by Lord Liverpool that extolled the virtues of mono-metallism.
Following the Indian Mutiny in 1857, the British government took direct control of British India. Since 1851, gold sovereigns were being produced in large numbers at the Royal Mint branch in Sydney, New South Wales. In the year 1864 in an attempt to make the British gold sovereign become the 'imperial coin', the treasuries in Bombay and Calcutta were instructed to receive gold sovereigns. These gold sovereigns however never left the vaults. As was realized in the previous decade in Canada and the next year in Hong Kong, existing habits are not easy to replace. And just as the British government had finally given up any hopes of replacing the rupee in India with the pound sterling, they simultaneously realized, and for the same reasons, that they could not easily replace the silver dollar in the Straits Settlements with the Indian rupee, as had been the desire of the British East India Company.
Since the great silver crisis of 1873, a growing number of nations had been adopting the gold standard. In 1898, following the recommendations of the Indian Currency Committee, British India officially adopted the gold exchange standard by pegging the rupee to the British pound sterling at a fixed value of 1 shilling 4 pence (i.e., 15 rupees = 1 pound). In 1920, the actual silver value of the rupee was increased in value to 2 shillings (10 rupees = 1 pound). In British East Africa at this time, the decision was made to replace the rupee with a florin. No such opportunity was, however, taken in British India.
In 1927, the peg was once more reduced, this time to 18 pence (13⅓ rupees = 1 pound). This peg was maintained until 1966, when the rupee was devalued and pegged to the U.S. dollar at a rate of 7.5 rupees = 1 dollar (at the time, the rupee became equal to 11.4 British pence). This peg lasted until the U.S. dollar devalued in 1971.
The Indian rupee replaced the Danish Indian rupee in 1845, the French Indian rupee in 1954 and the Portuguese Indian escudo in 1961. Following independence in 1947, the Indian rupee replaced all the currencies of the previously autonomous states. Some of these states had issued rupees equal to those issued by the British (such as the Travancore rupee). Other currencies included the Hyderabad rupee and the Kutch kori. The nominal values during British rule (and the first decade of independence) were:
 1 damidi(pie) = 0.520833 paise
 1 kani(pice) = 1.5625 paise
 1 paraka = 3.125 paise
 1 anna = 6.25 paise (1 Anna)
 1 beda = 12.5 paise (2 Anna)
 1 pavala = 25 paise (4 Anna)
 1 artharupee = 50 paise (8 Anna)
 1 rupee = 100 paise (16 Anna)
In 1957, decimalisation occurred, and the rupee was divided into 100 naye paise (Hindi for "new paise"). In 1964, the initial "naye" was dropped. Many still refer to 25, 50 and 75 paise as 4, 8 and 12 annas, respectively, not unlike the usage of "bit" in American English for ⅛ dollar.
 The rupee on the East African coast and South Arabia 
In East Africa, Arabia, and Mesopotamia, the Rupee and its related coins were current at various times. The usage of the Rupee in East Africa extended from Somalia in the north, to as far south as Natal. In Mozambique, the British India rupees were overstamped. In Kenya, the British East Africa Company minted the rupee and its fractions as well as pice. The rise in the price of silver, immediately after the First World War, caused the rupee to rise in value to two shillings sterling. In 1920 in British East Africa, the opportunity was then taken to introduce a new florin coin, hence bringing the currency into line with sterling. Shortly after that, the Florin was split into two East African shillings. This assimilation to sterling did not however happen in British India itself. In Somalia the Italian colonial authority minted 'rupia' to exactly the same standard, and called the pice 'besa'.
 The rupee in the Straits Settlements 
The Straits Settlements were originally an outlier of the British East India Company. The Spanish dollar had already taken hold in the Straits Settlements by the time the British arrived in the nineteenth century, however, the East India Company tried to introduce the rupee in its place. These attempts were resisted by the locals, and by 1867 when the British government took over direct control of the Straits Settlements from the East India Company, attempts to introduce the rupee were finally abandoned.
 International use 
Pakistani rupee
With Partition, the Pakistani rupee came into existence, initially using Indian coins and Indian currency notes simply overstamped with "Pakistan". In previous times, the Indian rupee was an official currency of other countries, including Aden, Oman, Kuwait, Bahrain, Qatar, the Trucial States, Kenya, Tanganyika, Uganda, the Seychelles, and Mauritius.
The Indian government introduced the Gulf rupee, also known as the Persian Gulf rupee (XPGR), as a replacement for the Indian rupee for circulation exclusively outside the country with the Reserve Bank of India [Amendment] Act, 1 May 1959. This creation of a separate currency was an attempt to reduce the strain put on India's foreign reserves by gold smuggling. After India devalued the rupee on 6 June 1966, those countries still using it – Oman, Qatar, and the Trucial States (which became the United Arab Emirates in 1971) – replaced the Gulf rupee with their own currencies. Kuwait and Bahrain had already done so in 1961 and 1965 respectively.
The Bhutanese ngultrum is pegged at par with the Indian rupee, and both currencies are accepted in Bhutan. The Indian rupee is also accepted in towns in Nepal which lie near the border with India. However, the Indian Rupee denominations of 500 and 1000 are banned in Nepal.
 Convertibility 
Officially, the Indian rupee has a market-set exchange rate. However, the RBI trades actively in the USD/INR currency market to impact effective exchange rates. Thus, the currency regime in place for the Indian rupee with respect to the US dollar is a de facto controlled exchange rate. This is sometimes called a managed float. Other rates such as the EUR/INR and INR/JPY have volatilities that are typical of floating exchange rates. It should be noted, however, that unlike China, successive administrations (through RBI, the central bank) have not followed a policy of pegging the INR to a specific foreign currency at a particular exchange rate. RBI intervention in currency markets is solely to deliver low volatility in the exchange rates, and not to take a view on the rate or direction of the Indian rupee in relation to other currencies.
Also affecting convertibility is a series of customs regulations restricting the import and export of rupees. Legally, foreign nationals are forbidden from importing or exporting rupees, while Indian nationals can import and export only up to 5000 rupees at a time, and the possession of 500 and 1000 rupee notes in Nepal is prohibited.
RBI also exercises a system of capital controls in addition to the intervention (through active trading) in the currency markets. On the current account, there are no currency conversion restrictions hindering buying or selling foreign exchange (though trade barriers do exist). On the capital account, foreign institutional investors have convertibility to bring money in and out of the country and buy securities (subject to certain quantitative restrictions). Local firms are able to take capital out of the country in order to expand globally. But local households are restricted in their ability to do global diversification. However, owing to an enormous expansion of the current account and the capital account, India is increasingly moving towards de facto full convertibility.
There is some confusion regarding the interchange of the currency with gold, but the system that India follows is that money cannot be exchanged for gold, in any circumstances or any situation. Money cannot be changed into gold by the RBI. This is because it will become difficult to handle it. India follows the same gold-interchange principle as Great Britain and America.
Chronology
 1991 - India began to lift restrictions on its currency. A series of reforms remove restrictions on current account transactions including trade, interest payments & remittances and on some capital assets-based transactions. Liberalized Exchange Rate Management System (LERMS), a dual exchange rate system, introduced a partial convertibility of the Rupee in March 1992.
 1997 - A panel set up to explore capital account convertibility recommended India move towards full convertibility by 2000, but timetable abandoned in the wake of the 1997-98 East Asian financial crisis.
 2006 - The Prime Minister, Dr Manmohan Singh, asks the Finance Minister and the Reserve Bank of India to prepare a road map for moving towards capital account convertibility.


Barack Obama: December 2024
Barack Hussein Obama II (b ə ˈ r ɑː k _ h uː ˈ s eɪ n _ oʊ ˈ b ɑː m ə En-us-Barack-Hussein-Obama.ogg; born August 4, 1961) is an American politician and attorney. He was the 44th president of the United States from 2009 to 2017. He was the first African-American president in U.S. history. A member of the Democratic Party, he also served as member of the Illinois Senate from 1997 to 2004 and a United States senator from Illinois from 2005 to 2008.
Obama was born in Honolulu, Hawaii. He married Michelle Robinson in 1992. They have two daughters, Malia Obama and Sasha Obama.
Obama was inaugurated in January 2009, as the first African American mixed-race president. As president, he slowly ended US participation in the Iraq War, having prepared the country to defend itself. The al-Qaeda terrorist leader Osama bin Laden was killed while Obama was in office. Also, he contributed to the overthrow of Muammar Gaddafi in Libya. Obama signed the Patient Protection and Affordable Care Act (often called "Obamacare") which changed many health care laws. He also enacted many acts to create public works jobs to help the economy. He became the first president to openly express support for gay marriage, and proposed gun control as a result of the Sandy Hook school shooting.
He was reelected in 2012. During his second term, the government partially shut down. He was able to open diplomatic relations with Cuba. In 2015, the United States joined the Paris Climate Agreement. He attempted to nominate Merrick Garland to the Supreme Court but was unsuccessful in doing so.
Obama left office in January 2017 and was succeeded by Republican Donald Trump. He now lives in Washington, D.C. He has ranked high in presidential opinion polls.
 Early life 
Barack Hussein Obama II was born on August 4, 1961 in Kapiʻolani Medical Center for Women and Children (called Kapiʻolani Maternity & Gynecological Hospital in 1961) in Honolulu, Hawaii. He is the first President to have been born in Hawaii. His father was a black exchange student from Kenya named Barack Obama Sr. He died in a motorcycle accident in Kenya in 1982. His mother was a white woman from Kansas named Ann Dunham, who was an anthropologist and died in 1995, from uterine cancer. 
He spent most of his childhood in Hawaii and Chicago, Illinois, although he lived in Jakarta, Indonesia with his mother and stepfather from age 6 to age 10. He later moved back to Hawaii to live with his grandparents. Obama is one of 8 siblings. 
 Education 
He started college at Occidental College in Los Angeles, and graduated from Columbia University in New York City. After taking time off as a community organizer, Obama went to law school at Harvard University. After law school, Obama worked for a law firm in Hyde Park, Chicago.
 Marriage and family 
Obama has been married to Michelle Obama since 1992. She has a Juris Doctor degree from Harvard Law School. She worked as a lawyer. They have two daughters, Malia Ann, who was born in 1998 and Natasha ("Sasha"), born in 2001. They were born at University of Chicago Medical Center in Chicago. They lived in Chicago, but moved into the White House on January 20, 2009.
Obama promised his daughters that the family would get a dog if he was elected president. In April 2009, Senator Ted Kennedy, the brother of former President John F. Kennedy, gave Obama one of his dogs, a Portuguese water dog named Bo.
Obama has a half sister who is a teacher in Hawaii. His father died from a car accident in Kenya. His mother died of ovarian cancer. His maternal grandmother died just before Obama won the election to become President.
 Political career 
Obama worked for Alice Palmer, an Illinois state senator. In 1995, she chose not to run for re-election so that she could run for U.S. Congress, and Obama decided to run for her Illinois state senate seat. Palmer lost her election for U.S. Congress, so she tried to keep her seat in the state senate, but she did not have enough time to meet the rules of the election. Obama's team said that she could not be on the ballot, and the election rule makers agreed. Obama won the election and became an Illinois state senator. He was state senator from 1997 to 2004.
While he was Illinois state senator, he wrote a law that required police to keep records on the race of people they stopped. The law that he wrote also forced police to videotape when they talked to people they suspect of murder. He taught law part-time at the University of Chicago Law School. Judge and political teacher Abner J. Mikva taught Obama politics and became his mentor. During his early political career, Obama would make appearances and debate on Chicago Tonight.
Obama ran for the U.S. Senate. While running for Senate, John Kerry asked him to speak at the Democratic National Convention. He spoke on television. He was a U.S. Senator from 2005 to 2008.
Obama won the presidential election of 2008.
 2008 and 2012 presidential campaigns 
 2008 presidential campaign 
Obama's presidential campaign for the White House started in early June 2008, when he defeated Hillary Clinton in the 2008 Democratic primaries. Hillary Clinton was favored to win but Obama won many smaller state caucuses (local party elections) by having a lot of volunteers. He decided not to accept government money for his campaign so that he could accept more private money under Campaign finance reform in the United States. He raised the most amount of money ever for a presidential campaign. August 2016
Obama's campaign theme was that he was a man of hope and change. He was also against the war in Iraq. He was in favor of giving money to American car companies. He was in favor of sending more troops to Afghanistan.
During the campaign, some people said that Obama's friends were Tony Rezko, a landlord, and former revolutionary Bill Ayers; Obama said that they were not his friends. August 2016 Obama also had trouble when his minister at church, Jeremiah Wright, was videotaped criticizing America. During the campaign, Obama said that his opponent, Republican candidate John McCain, was just like George W. Bush, something that John McCain said was not true. He ran with Joe Biden as his candidate for Vice President.
He defeated McCain in the election on November 4 by a wide electoral majority of 365 to 173, meaning that he won the most votes in enough states to send 365 people to officially elect him. The popular vote (based on the total number of votes across the country) was closer, with Obama winning 53%, McCain 46%.
 2012 presidential campaign 
Obama announced he was running for president again in April 2011, when he posted a video on his website. Because he was already the president, there were very few other Democrats who tried to oppose him. He won the democratic nomination easily. Their opponents in the Republican party this time were Mitt Romney, who was running for president, and Paul Ryan, who was running for vice president.
In the election on November 6, Obama and Joe Biden defeated Romney and Ryan by a majority of 332 to 206 electoral votes. This meant that, even though it was still large, his majority was smaller than in 2008. In terms of the popular vote, Obama won 51.1% and Romney won 47.2%.
 Presidency, 2009–17 
 First term, 2009–13 
Obama was first sworn in as president on January 20, 2009. 
 Great Recession 
When Obama was sworn in, the United States was battling a tough recession. He asked Congress to spend an extra $787 billion ($787,000,000,000) to try to end the recession. He called the plan the stimulus bill. The stimulus bill funded many road projects, gave money to schools, gave tax credits to many Americans, and funded many science and research projects.
He continued the financial bailout that George W. Bush started, giving billions of dollars to car companies and banks so that they would not go bankrupt. He signed an act written by Barney Frank and Chris Dodd which would regulate Wall Street (the financial industry) to try to prevent another recession like this from happening again.
 Obamacare 
Obama said he would change the health care system in the United States in order to make healthcare more affordable for Americans. He signed the Patient Protection and Affordable Care Act (also known as Obamacare) in 2010. This brought health care reform to the United States.
 Nobel Peace Prize 
Obama received the 2009 Nobel Peace Prize on October 9, 2009. He noted that his efforts were humble, but he donated the prize money to several charities.
 Tea Party movement 
Though his popularity was very high (around 70% approval) when he entered office, his approval ratings fell to 45% percent during the year of 2010. He received much criticism from Republicans, conservatives, libertarians, and members of the Tea Party as they believed that the federal government was becoming too big and spending too much money, and that his programs were not the best for the country.
 War in Iraq 
Obama made a plan to slowly withdraw troops from Iraq, ending the War in Iraq by the end of 2011, while adding more troops to Afghanistan to help the United States win the War in Afghanistan. He also decided that the United States should help in the war against Libya. He has said several times that he wants to improve U.S. relations with the Muslim world. Obama reduced US participation in the Iraq War and continued the war on terror which resulted in the death of Osama bin Laden on May 2, 2011. Obama started a no-fly-zone policy on the Libyan civil war that ended in October 2011 with the killing of Muammar al-Gaddafi.
 Economic policy 
With rising economic deficits (the amount of money the government borrows each month) under his administration, he called for taxes to be increased on the rich. He criticized his Republican opponents for wanting to cut welfare benefits for the poor rather than raising taxes to help pay down the debt.
 LGBT rights 
He signed the Don't Ask Don't Tell Repeal Act of 2010 in 2010, allowing openly gay men and openly lesbian women in the armed forces. On May 9, 2012, he became the first sitting US President to openly support legalizing same-sex marriage.
 Gun control 
On December 14, 2012, after the school shooting in Newtown, Connecticut occurred, Obama had said, "We're going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics". On December 21, 2012, Obama and his White House staff observed a moment of silence because of the school shooting in Connecticut.
Before his second term began, there has been debating of guns because of the shooting in Newtown, Connecticut that happened on December 14, 2012, as well as shootings in the past.
 2012 re-election campaign 
On April 4, 2011 Obama said that he would run for re-election for a second term in 2012 in a video titled "It Begins with Us" that he posted on his website and filed election papers with the Federal Election Commission. He was officially nominated as his party's nominee on September 6, 2012. Mitt Romney was officially nominated as his opponent by the Republican party on August 30, 2012. While the election results were very close, Obama easily won the electoral college votes he needed to win a second term. Obama and Romney spent more than $2 billion on advertising during the election campaign.
On December 21, 2012, Obama nominated John Kerry for United States Secretary of State during his second term. Kerry was sworn in on February 1, 2013.
 Second term, 2013–17 
Obama was inaugurated for a second term privately (only his family members could see) on January 20, 2013, at the White House. The next day, January 21, 2013, he was inaugurated again, this time in public, at the United States Capitol. This was because January 20, 2013, was on a Sunday. 
The start of his second term in 2013 had a few setbacks. With the NSA, people were upset at the Obama administration that the government was possibly listening to their phone calls. His party (the Democrats) also lost the Congressional elections. Because of disagreements between Democrats and Republicans in Congress, neither side was getting anything done and Obama resulted in using his Executive Order (his power as president) to help reform things like the immigration system. 
He visited South Africa in late June 2013. Prior to visiting South Africa, he visited Senegal. He visited Robben Island, where Mandela was imprisoned. He did not meet with Nelson Mandela.
 2013 United States federal government shutdown 
The United States government shutdown occurred on October 1, 2013. On October 17, 2013, Obama signed a bill that ended the United States government shut down.
 Presidential Medals of Freedom 
Obama awarded several people, including former U.S. President Bill Clinton and media mogul Oprah Winfrey for the Presidential Medal of Freedom on November 20, 2013. He has awarded the Presidential Medal of Freedom to many people, such as Stephen Hawking, Sandra Day O'Connor, Chita Rivera, Loretta Lynn and George H. W. Bush.
 Death of Nelson Mandela 
On December 5, 2013, he gave a four-and-a-half-minute speech of Nelson Mandela after Mandela's death was announced. On December 9, 2013, he departed Washington, D.C. to go to South Africa for Mandela's memorial service. On December 10, 2013, Obama spoke at the memorial service of Nelson Mandela in Soweto, South Africa.
 Minimum wage and college 
He supported increasing the minimum wage, requiring women to be paid the same as men at the same job, and has called for the first 2 years of college to be fully government-funded for students who study full-time and get good grades.
 Legalization of same-sex marriage 
Obama supported LGBT members, and successfully convinced the courts in 2015 that same-sex marriage should be legal in the United States.
 Climate change 
Obama was also worried about climate change, and promoted the Paris Agreement on climate change.
 Nomination of Merrick Garland to the Supreme Court 
After the death of Supreme Court justice Antonin Scalia, Obama nominated Merrick Garland to replace him on March 16, 2016, but the nomination expired because the Senate refused to hold a vote for him.
 Post-presidency, 2017–present 
As it is not possible for a person to be president for three terms, Obama could not run for president again. He was succeeded by Republican Donald Trump in early 2017. He left office with a 60% approval rating.
Even though he is not the president anymore, Obama still owns a house in Washington, D.C.
Obama and his wife, Michelle, spend time making speeches and attending events. They also run a charity called the Obama Foundation, and own Higher Ground Productions, a company which makes movies. The company was hired by Netflix to make documentaries. One of their documentaries, American Factory, won an Academy Award for being the best documentary of 2019.
He released his presidential memoir, A Promised Land, on November 17, 2020.
In May 2020, Obama strongly criticized President Donald Trump for his response to the coronavirus pandemic, saying that it is "an absolute chaotic disaster".


Vaccine: A vaccine is a biological preparation. It is given to prevent a specific infectious or malignant disease. It only works against the microorganism for which it is prepared. It is usually given by injection, and called vaccination. 
At its best, vaccination gives immunity to an infectious disease caused by a particular microorganism (bacteria or virus). For example, the flu vaccine makes it very much less likely that a person will get the flu. The flu virus continually changes, and has many strains. That is why re-vaccination is needed every year. 
At first, vaccines were usually made from something that is alive, or was alive. Now they may be built up by viral biochemistry. Each vaccine has its own history, and what is true of one might not be true of another.
The word "vaccine" comes from the Latin vacca, meaning "cow"). In 1796, Edward Jenner used a milkmaid infected with cowpox (variolae vaccinae) to protect people against smallpox. The use of vaccines is called vaccination.
Vaccination had been done before Jenner. Powdered smallpox material was blown up the nostrils of the subject.
 History 
Edward Jenner created the first vaccine in the 1770s. At this time, smallpox was a deadly disease. Jenner noticed that people who had already had cowpox (a disease that is related to smallpox) usually did not get smallpox. He thought that getting cowpox protected people against smallpox.
To test this idea, Jenner gave a boy cowpox. Then he infected the boy with smallpox. The boy did not get sick because he had already had cowpox. Jenner was right: having cowpox protected people against smallpox.
Because cowpox inoculation made fewer people sick than smallpox inoculation, England made smallpox inoculation illegal in 1840. In 1853, they made another law that said every child had to be vaccinated against smallpox using Jenner's vaccine.
In the 19th century, Louis Pasteur made a rabies vaccine.
In the 20th century, scientists created vaccines to protect people against diphtheria, measles, mumps, and rubella. In the 1950s, Jonas Salk created the polio vaccine.
However, vaccines still do not exist for many important diseases, like malaria and HIV.
Many countries have passed compulsory vaccination laws – laws that require certain people to get vaccinated. For example, in many countries, children have to be vaccinated against certain diseases in order to go to public school. On the other hand, there are some religions which ban all forms of vaccination: the Seventh-day Adventist Church is an example.
Types of vaccines
There are many different types of vaccines.
One common type of vaccine is a "live vaccine". This type of vaccine contains a small amount of a live virus or bacteria. Before the vaccine is given, scientists weaken the virus or bacteria so it cannot make a person sick. When a person gets a live vaccine, their immune system learns to recognize and fight off that virus or bacteria. hen, if the person is exposed to the virus or bacteria in the future, their immune system will already "know" how to fight it off. Examples of live vaccines include vaccines for measles, mumps, and chickenpox.
Another common type of vaccine is an "inactivated vaccine". These vaccines contain dead viruses or bacteria. These do not cause the immune system to react as strongly as live vaccines. Because of this, people may need "booster shots" – extra doses of the vaccine, given at certain times, so their immune system can "learn" how to fight off the infection. Examples of inactivated vaccines include vaccines for pertussis (whooping cough), rabies, and hepatitis B.
In other vaccines, only a protein molecule from the virus or bacterium is injected into the patient. The protein is enough for the patient's immune system to recognize the whole germ.
With messenger RNA vaccines, only the messenger RNA (mRNA), which acts as a blueprint or recipe for the protein, is injected into the patient. The first mRNA vaccines were made in the 1990s, but scientists did not make large numbers of them until the 2010s. Some mRNA vaccines work against cancer and can make tumors smaller.
 Effectiveness 
Vaccines do not guarantee complete protection from a disease. In other words, a person can get a disease that they were vaccinated against.
Sometimes, this happens because the person's immune system did not respond to the vaccine (it did not "learn" how to fight off the disease after the person got the vaccine). This may happen because the person's immune system is already weak (for example, because of diabetes, HIV infection, old age, or steroid use). It may also happen because the person's immune system cannot make the particular B cells which make the antibodies that stick to the pathogen.
Some vaccines work better than others at protecting people from a disease. The decrease in getting the disease is called efficacy. For example, if 80% fewer vaccinated people get the disease, 80% is the efficacy. There are many reasons for different efficacy:
 Vaccination works better for some diseases than for others
 The vaccine may be for a certain strain of a disease. If a person gets a different strain of the disease, they can still get sick.
 Vaccines usually do not have permanent effects, so a person might need many different vaccinations on a schedule. If a person missed a scheduled vaccine, they might lose their protection against a disease.
 Some people are "non-responders" to certain vaccines. This means that their immune systems just do not create antibodies to fight off a disease, even after they are vaccinated correctly.
 Other things, like ethnicity, age, and genetics, can affect how a person reacts to a vaccine. In some cases, larger doses are used for older people (50–75 years and up), whose immune response to a given vaccine is not as strong.
Controversy
Since vaccines first existed, there have been people who did not agree with the idea of using vaccines. Around the world, most scientists and doctors agree that the benefits of using vaccines are much greater than the risks. The adverse effects from vaccines are rare. Not vaccinating people is a much greater risk, because vaccines prevent suffering and death from infectious diseases.
There have been controversies over using vaccines such as whether vaccines are safe, the amount of research and whether it is morally right to force people to get vaccinated.
Some religious groups do not allow uses of vaccines.
Some political groups argue that people should be able to choose whether or not to get vaccinated. They argue that laws requiring people to get vaccinated violate individual rights. In response, one study says: "Vaccine refusal not only increases the individual risk of disease but also increases the risk for the whole community".
Some parents choose not to follow the regular vaccine schedule for their children. One study looked at parents of children ages six months to six years old. It found that 13% of these parents reported following an alternative vaccination schedule. However, of these parents, less than 1 out of every 5 reported refusing all vaccines. Most refused only certain vaccines, and/or delayed some vaccines until the child was older.
Parents who delay vaccines until their children are older are often concerned about their child's immune system being too young and weak to handle getting many vaccines at once. However, this is a technical issue which is best decided by experts.
 Economics of development and patents 
One challenge in developing vaccines is economic. The diseases that most need vaccines today – HIV, malaria, and tuberculosis – exist mostly in poor countries. Companies that make vaccines would not make much money because many of the people who need them are too poor to pay for them. There would also be financial and other risks to these companies if they tried making new vaccines for these diseases.
Throughout history, most vaccines have been developed by governments, universities, and non-profit organizations. Many vaccines have been highly cost-effective and good for public health. In recent decades, the number of vaccines given throughout the world has increased dramatically. This increase, particularly in the number of different vaccines given to children before they start school, may be due to laws and support from governments.
Another obstacle to making new vaccines is that when a new vaccine is made, the maker usually files a patent on their vaccine. These patents can limit the process used to make the vaccine to the maker (in practice the right can be subcontracted). That way the patent makes money for the originator.
 Additional components in vaccines 
Vaccines often contain other things besides the active vaccine (the weakened or dead virus or bacteria). For example, vaccines may contain:
 Aluminum salts or gels. These are added to help the immune system respond earlier, and more strongly, to the vaccine. They allow a lower dose of the vaccine to be given.
 Antibiotics are added to some vaccines to prevent bacteria from growing while the vaccine is being made or stored.
 Egg protein is present in influenza and yellow fever vaccines, because they are made using chicken eggs. Vaccines may also contain other proteins.
 Formaldehyde is used to kill bacteria for certain vaccines. It is also used to kill unwanted viruses and bacteria that might get into the vaccine while it is being made.
 Monosodium glutamate (MSG) and 2-phenoxyethanol are used as stabilizers in a few vaccines to make sure the vaccine does not change if it is exposed to heat, light, acidity, or humidity.
 Thimerosal is a preservative that contains mercury. It is added to vials of vaccine that contain more than one dose, to keep harmful bacteria from growing in the vaccine.
Preservatives in vaccines, such as thiomersal, phenoxyethanol, and formaldehyde, prevent serious adverse effects. Thiomersal is more effective against bacteria, lasts longer in storage, and makes the vaccine stronger, safer, and more stable (less likely to be changed by things like heat). However, in the United States, the European Union, and a few other developed countries, it is no longer used as a preservative in childhood vaccines because it contains mercury.
If no preservative is added to a vaccine, harmful bacteria may grow in the vaccine. For example, in 1928, Staphylococcus bacteria grew in a diphtheria vaccine that had no preservative in it. Of 21 children who got that vaccine, 12 died.
Most versions of anti-coronavirus are kept at very low temperature before use. That helps preserve the vaccine in its most effective state.
 Use in veterinary medicine 
Animals are vaccinated to keep them from getting diseases, and to keep them from infecting humans with diseases. Pets as well as livestock are routinely vaccinated.
In some instances, populations of wild animals may be vaccinated. Sometimes, wild animals are vaccinated by spreading vaccine-laced food in a disease-prone area. This method has been used to try to control rabies in raccoons. Where rabies occurs, laws may require dogs to get rabies vaccinations.
Dogs can also be vaccinated against many other diseases, including canine distemper, canine parvovirus, infectious canine hepatitis, adenovirus-2, leptospirosis, bordatella, canine parainfluenza virus, and Lyme disease.
 Several trends in vaccine development 
 Nowadays, vaccines are given to people of all ages.
 Combinations of vaccines are becoming more common. Vaccines containing five or more parts are used in many parts of the world.
 New methods of giving vaccines are being developed. Some of these new delivery systems include skin patches, aerosols given through inhalation devices, and eating genetically engineered plants.
 Scientists are designing vaccines to make people's natural immune responses stronger.
 Scientists are trying to make vaccines to help cure chronic infections, instead of only preventing disease.
 Public health officials might change their strategies for giving vaccines based on differences in how men, women, and pregnant women react to vaccines.
Scientists are also working on vaccines against many noninfectious human diseases, such as cancers and autoimmune disorders. For example, the experimental vaccine CYT006-AngQb has been investigated as a possible treatment for high blood pressure.


The International Library of Psychology, Philosophy and Scientific Method: The International Library of Psychology, Philosophy and Scientific Method was a famous and important series of monographs published from 1922 to 1965. They were edited by Charles Kay Ogden, and published by Kegan Paul, Trench Trubner & Co. in London. This series published some important book on psychology and philosophy, especially the thought of the Vienna Circle in English. It published some of the best psychologists and philosophers of the time, such as Alfred Adler, C. D. Broad, Rudolf Carnap, F. M. Cornford, Edmund Husserl, Carl Jung, Kurt Koffka, Ernst Kretschmer, Bronisław Malinowski, Karl Mannheim, George Edward Moore, Jean Nicod, Jean Piaget, Frank P. Ramsey, Otto Rank, W. H. R. Rivers, Louis Leon Thurstone, Jakob von Uexküll, Hans Vaihinger, Edvard Westermarck, William Morton Wheeler, Ludwig Wittgenstein, J. N. Findlay and others. Most of the 204 books in the series have been reprinted, some in revised editions.
 List of books in the series 
Listed alphabetically by author, with date of original publication (many have been reprinted).
 Adler, Alfred. Individual psychology, 2ed (1924).
 Adler, Mortimer J. Dialectic (1927).
 Anton, John P. Aristotle's theory of contrariety (1957).
 Bentham, Jeremy. The theory of legislation (1931).
 Black, Max. The nature of mathematics (1933).
 Bogoslovsky, Boris. The technique of controversy: principles of dynamic logic (1928).
 Broad, C. D. The mind and its place in nature (1925).
 Buchanan, Scott. The doctrine of signatures (1938).
 Buchanan, Scott. Possibility (1927).
 Buchler, Justus. Charles Peirce's empiricism (1939). Foreword by Ernest Nagel.
 Bühler, Karl. The mental development of the child (1930).
 Burrow, Trigant. The social basis of consciousness: a study in organ psychology based upon a synthetic and societal concept of neuroses (1927).
 Burtt, Edwin Arthur. The metaphysical foundations of modern physical science (1924).
 Cairns, Huntington. Law and the social sciences (1935). Foreword by Roscoe Pound.
 Carnap, Rudolf. The logical syntax of language (1937).
 Cornford, F. M. Plato's theory of knowledge (1935).
 De Sanctis, Sante. Religious conversion (1927).
 Downey, June. Creative imagination: studies in the psychology of literature (1929).
 Florence, Philip Sargant. The statistical method in economics and political science (1929).
 Hartmann, Karl Robert Eduard von. Philosophy of the unconscious (1931).
 Horney, Karen. Neurosis and Human Growth (1951)
 Hulme, T. E. Speculations: essays on humanism and the philosophy of art (1924). Edited by Herbert Read.
 Humphrey, George. The nature of learning in its relation to the living system (1933).
 Jaensch, Erich Rudolf. Eidetic imagery and typological methods of investigation: their importance for the psychology of childhood (1930).
 Jung, Carl. Contributions to analytical psychology (1928).
 Jung, Carl. Psychological types (1923).
 Koffka, Kurt. Growth of the mind (1924).
 Köhler, Wolfgang. The mentality of apes (1925).
 Kretschmer, Ernst. Physique and character (1931).
 Ladd-Franklin, Christine. Colour and colour theories (1929).
 Laignel-Lavastine, Maxime. The concentric method in the diagnosis of psychoneurotics (1931).
 Lange, Friedrich Albert. History of materialism (1925). Introduction by Bertrand Russell.
 Lazerowitz, Morris. The structure of metaphysics (1955).
 Leuba, James H. The psychology of religious mysticism (1925).
 Liang Qichao. History of Chinese political thought during the early Tsin period (1930).
 Liao, Wen Kwei. The Individual and the Community: A Historical Analysis of the Motivating Factors of Social Conduct (1933).
 Lodge, Rupert. Plato's theory of education (1947).
 Malinowski, Bronisław. Crime and custom in savage society (1926).
 Mannheim, Karl. Ideology and utopia (1936).
 Marston, William Moulton. Emotions of normal people (1928).
 Masson-Oursel, Paul. Comparative philosophy (1926). Introduction by Francis Graham Crookshank.
 Moore, G. E. Philosophical studies (1922).
 Nicod, Jean. Foundations of geometry and induction (1930).
 Ogden, Charles Kay. Bentham's theory of fictions (1932).
 Ogden, Charles Kay and Richards, I. A. The meaning of meaning (1923).
 Paulhan, Frédéric. The laws of feeling (1930).
 Piaget, Jean. The language and thought of the child (1926).
 Piéron, Henri. Thought and the brain (1927).
 Ramsey, Frank P. Foundations: essays in philosophy, logic, mathematics and economics (1931).
 Rank, Otto. The trauma of birth (1929).
 Richards, I. A. Mencius on the mind: experiments in multiple definition (1964).
 Rignano, Eugenio. Biological memory (1926).
 Rignano, Eugenio. The nature of life (1930).
 Rignano, Eugenio. The psychology of reasoning (1923).
 Ritchie, Arthur David. Scientific method: an inquiry into the character and validity of natural laws (1923).
 Rivers, W. H. R. Medicine, magic, and religion (1921).
 Rohde, Erwin. Psyche: The cult of souls and the belief in immortality among the Greeks (1925).
 Russell, Bertrand. The analysis of matter (1927).
 Smart, Ninian. Reasons and faiths: an investigation of religious discourse, Christian and non-Christian (1958).
 Stephen, Karin. The misuse of mind: a study of Bergson's attack on intellectualism (1922). Preface by Henri Bergson.
 Smith, W. Whately. The measurement of emotion (1922).
 Taba, Hilda. Dynamics of education: a methodology of progressive educational thought (1932).
 Thalbitzer, Sophus. Emotion and insanity (1926). Translated by M. G. Beard. Preface by Harald Høffding.
 Thurstone, Louis Leon. The nature of intelligence (1924).
 Tischner, Rudolf. Telepathy and clairvoyance (1925).
 Uexküll, Jakob von. Theoretical biology (1926).
 Vaihinger, Hans. The philosophy of 'As If''' (1924).
 Vossler, Karl. The spirit of language in civilization (1932).
 Werblowsky, R.J. Zwi. Lucifer and Prometheus: A Study of Milton's Satan (1952).
 Westermarck, Edvard. Ethical relativity (1932).
 Wheeler, William Morton. The social insects: their origin and evolution (1928).
 Wittgenstein, Ludwig. Tractatus Logico-Philosophicus (1922).
 Woodger, Joseph Henry. Biological principles (1929).
 Zeller, Eduard. Outlines of the history of Greek philosophy, 13th edition (1931).
 Zuckerman, Solly. The social life of monkeys and apes'' (1931).


Abraham Lincoln: April 2020
Abraham Lincoln (ˈ l ɪ ŋ k ən LINK ən; February 12, 1809 – April 15, 1865) was an American politician who served as the 16th president of the United States from 1861 until his assassination in 1865. He led the United States through the American Civil War, defeating the Confederate States of America and abolished slavery in the United States. Lincoln has been remembered as the Great Emancipator because he worked to end slavery in the United States. Lincoln is ranked in presidential historians as the greatest president in U.S. history.
 Life 
Abraham Lincoln was born on February 12, 1809, in Hodgenville, Kentucky, United States. His parents were Thomas Lincoln and Nancy Hanks. His family was very poor. Abraham had one brother and one sister. His brother died in childhood. They grew up in a small log cabin, with just one room inside. Although slavery was legal in Kentucky at that time, Lincoln's father, who was a religious Baptist, refused to own any slaves. 
When Lincoln was seven years old, his family moved to Indiana. Later, they moved to Illinois. In his childhood he helped his father on the farm, but when he was 22 years old he left home and moved to New Salem, Illinois, where he worked in a general store.
Later, he said that he had gone to school for just one year, but that was enough to learn how to read, write, and do simple math. When he was 21, he worked on a flatboat that carried freight. In 1842, he married Mary Todd. They had four children, but three of them died when they were very young.
Abraham Lincoln was sometimes called Abe Lincoln or "Honest Abe" because of a legend stating that he ran miles to give a customer the right amount of change. The nickname "Honest Abe" came from a time when he started a business that failed. Instead of running away like many people would have, he stayed and worked to pay his debt.
 Early political career 
Lincoln started his political career in 1832 when he ran for the Illinois General Assembly, but he lost the election. He served as a captain in the Illinois militia during the Black Hawk War, a war with Native American tribes. When he moved to Springfield in 1837, he began to work as a lawyer. Soon, he became one of the most highly respected lawyers in Illinois.
In 1837, as a member of the Illinois General Assembly, Lincoln issued a written protest of its passage of a resolution stating that slavery could not be abolished in Washington, D.C.
In 1841, he won a court case (Bailey v. Cromwell). He represented a black woman who claimed she had already been freed and could not be sold as a slave. In 1847, he lost a case (Matson v. Rutherford) representing a slave owner (Robert Matson) claiming the return of fugitive slaves. After he moved to Illinois, he worked as a shopkeeper and postmaster. He rode the circuit of courts for many years.
In 1846, Lincoln joined the Whig Party and was elected to one term in the House of Representatives. After that, he ignored his political career and instead worked as a lawyer. In 1854, in reaction to the passage of the Kansas-Nebraska Act, Lincoln became involved in politics again. He joined the Republican Party, which had recently been formed in opposition to the expansion of slavery. In 1858, he wanted to become senator. He ran for senate against Stephen A. Douglas. Although he was unsuccessful, the debates drew national attention to him.
The Republican Party nominated him for the Presidential election of 1860.
 Presidency 
Lincoln was chosen as a candidate for the Republican Party, the second candidate to be nominated from the party. He was chosen in 1860 for different reasons. Among these reasons was that his views on slavery were less extreme than those of other people who wanted to be candidates. Lincoln was from what was then one of the Western states and had a bigger chance of winning the election there. Other candidates that were older or more experienced than him had enemies inside the party. Lincoln's family was poor, which added to the Republican position of free labor, the opposite of slave labor. Lincoln won the election in 1860 and was made the 16th President of the United States. He won with almost no votes in the South. For the first time, a president had won the election because of the large support he got from the states in the North. During his presidency Lincoln became well known because of his large stovepipe hat. He used his tall hat to store papers and documents when he was traveling.
 The Civil War 
After Lincoln's election in 1860, seven States (South Carolina, Mississippi, Alabama, Florida, Georgia, Texas and Louisiana) formed the Confederate States of America. When the United States refused to surrender Fort Sumter in Charleston, South Carolina, the Confederates attacked the fort, beginning the American Civil War. Later, four more states (Arkansas, Virginia, Tennessee, and North Carolina) joined the Confederacy for a total of eleven. In his whole period as president, he had to rebuild the Union with military force and many bloody battles. He also had to stop the "border states", like Kentucky, Missouri, and Maryland, from leaving the Union and joining the Confederacy.
Lincoln was not a general, and had only been in the army for a short time during the Black Hawk War. However, he still took a major role in the war, often spending days and days in the War Department. His plan was to cut off the South by surrounding it with ships, control the Mississippi River, and take Richmond, the Confederate capital. He often clashed with generals in the field, especially George B. McClellan, and fired generals who lost battles or were not aggressive enough. Eventually, he made Ulysses S. Grant the top general in the army.
 Emancipation Proclamation 
With the Emancipation Proclamation begun on January 1, 1863, Lincoln ordered the freedom of all slaves in those states still in rebellion during the American Civil War. It did not actually immediately free all those slaves however, since those areas were still controlled by the rebelling states of the Confederacy. Only a small number of slaves already behind Union lines were immediately freed. As the Union army advanced, nearly all four million slaves were effectively freed. Some former slaves joined the Union army after 1862.
The Proclamation also did not free slaves in the slave states that had remained loyal to the Union (the federal government of the US). Neither did it apply to areas where Union forces had already regained control, as in Tennessee. Until the Thirteenth Amendment to the U.S. Constitution in 1865, only the states had power to end slavery within their own borders, so Lincoln issued the proclamation as a war measure.
The Proclamation made freeing the slaves a Union goal for the war, and put an end to movements in European nations (especially in Great Britain and France) that would have recognized the Confederacy as an independent nation. Lincoln then sponsored a constitutional amendment to free all slaves. The Thirteenth Amendment, making slavery illegal everywhere in the United States, was passed late in 1865, eight months after Lincoln was assassinated.
 Gettysburg Address 
Lincoln made a famous speech after the Battle of Gettysburg in 1863 called the Gettysburg Address. The battle was very important, and many soldiers from both sides died. The speech was given at the new cemetery for the dead soldiers. It is one of the most famous speeches in American history.
 Second term and assassination 
Lincoln was re-elected president by a small number of votes in 1864 and re-inaugurated on March 4, 1865. Soon afterward, it appeared likely that the Union would win the Civil War. Lincoln wanted to make it easy for states that had rebelled to restore self-government. On April 9, 1865, the leading Confederate general, Robert E. Lee, surrendered his armies. On April 11, 1865, Lincoln gave a speech in which he promoted voting rights for black American citizens.
During the day on April 14, 1865, Lincoln signed the law that created the secret service, the US President's security force. On the evening of April 14, Lincoln went to attend a play with his wife, Mary Todd at Ford's Theater in Washington, D.C.. He had invited Ulysses S. Grant to attend the play with him and his wife Mary Todd, and Grant planned to attend. As a general, Grant would have brought his own extra military security force, but he did not attend the play because his wife Julia and Mary Todd did not get along well.
During the third act of the play, John Wilkes Booth, a well-known actor and a Confederate spy from Maryland, entered the presidential box and shot Lincoln at point-blank range, mortally wounding him and screamed "Sic semper tyrannis" ("Thus always to tyrants"). An unconscious Lincoln was carried across the street to Petersen House. He was placed diagonally on the bed because his tall frame would not fit normally on the smaller bed. He remained in a coma for nine hours before dying the next morning. According to some accounts, at his last drawn breath, on the morning after the assassination, he smiled broadly and then expired. Lincoln was the first American president to be assassinated.
Booth escaped but died from shots fired during his capture on April 26. 
 Legacy 
Lincoln has been consistently ranked both by scholars and the public as one of the greatest U.S. presidents. He is often considered the greatest president in American history for his leadership during the American Civil War and his eloquence in speeches such as the Gettysburg Address.


Native Americans in the United States: Native Americans in the United States (also known as American Indians) are the indigenous people from the areas of North America now part of the continental United States, including parts of Alaska. The US government recognizes 574 tribes. There are about 310 Indian reservations in the US. Most Native Americans do not live on a reservation anymore.
There were and still are many diverse groups of Natives in what is now the US. The diversity includes various and rich languages and cultures. The arrival of Europeans in the Americas drastically changed Native Americans in the US. The history of these Native Americans is a story of suppression and the forced removal from their lands. During American history, there were various Native responses to European colonization and American expansion. In the 20th century, Natives got more rights and were recognized as citizens.
There are still problems today that impact Native Americans in the United States. Natives Americans face discrimination from other groups. There is also racism and cultural appropriation. There are also public health issues connected to historical trauma and generations of misstreatment.
Cultural Areas 
Historians often break up the cultures of Indigenous peoples of North America in the United States into two ten regions: 
 Arctic, including Aleut, Inuit, and Yupik peoples
 Subarctic
 Northeastern Woodlands
 Southeastern Woodlands
 Great Plains
 Great Basin
 Northwest Plateau
 Northwest Coast
 California
 Southwest
 History 
 Settlement and Pre-Columbia Era 
Native Americans most likely originally came from Asia to the Americas. They most likely crossed over Beringia. This was a geographical bridge that connected what is now Russia and Alaska. This migration may be over 30,000 years old. The Clovis culture was one of the earliest cultures.
The Pre-Columbian Era was before Columbus and Europeans conquered the Natives. Scholars break this era into different stages. The lithic stage was important for the usage of new rock technologies. In the archaic period, there was mainly subsistence farming. After the archaic period, societies were more developed. There were more crafts, urban centers, military structures, and usages of metals. Examples of tribes include Eastern Woodlands culture, the Pacific Northwest Coast Indigenous peoples, the Mississippian culture, including the Cahokia), Pueblo peoples and Iroquois League of Nations.December 2024December 2024
 European Exploration and Colonization 
Europeans started to arrive in the 16th century. This caused diseases to spread, and many Natives died. The population of Natives became much smaller. There were many conflicts between American Indians and colonists even into the 19th century. Natives fought to protect their lands. Europeans also brought animals. Natives began to hunt more and move around more with these new animals. European trade led to the Columbian Exchange.
There were several wars. Native Americans often fought against each other and Europeans. They also made many alliances. The  Beaver Wars were in the 17th century. Iroquis became powerful and destroyed other tribes like  Huron, Neutral, Erie, Susquehannock, and Shawnee. Natives fought with the French and British during the Seven Year's War. King Philip's War was between Metacom and Colonists in New England. It was the last major war between Natives and Colonists.
During the American Revolution, many Natives fought with the British. At the Treaty of Paris (1783), Britain gave most Native lands to America. George Washington and Americans wanted to civilize and educate Natives. The Civilization Fund Act of 1819 supported this process. Americans thought that some Natives were civilized. These were the Five Civilized Tribes. They included the Cherokee, Chickasaw, Choctaw, Creek and Seminole tribes.
 19th Century 
In the 19th century, most of the lands in the Eastern United States were conquered. The lands in the west were still Native American Territory. Soon diseases also came to the Western territories. The European Americans wanted to move west. There was Native American resistance. Conflicts included  Tecumseh's War, the Creek War and Seminole Wars. However, Native Americans were in the Union and Confederate Armies during the Civil War.
President Andrew Jackson forced Natives to leave their lands. He passed the  Indian Removal Act of 1830. This led to the Trail of Tears. Americans justified this removal. This was called Manifest Destiny. In 1851, the Indian Appropriations Act set up preservations for Natives. Natives resisted in the Indian Wars. There was also the Dakota War, Great Sioux War, Snake War, Colorado War, and Texas-Indian Wars. In the Wounded Knee Massacre, the US army killed many Natives.
The Cherokee were the first Natives to become US citizens.
In 1871, Ulysses S. Grant recognized more Native tribes in the Indian Appropriations Act. The US government also created many boarding schools for Native Americans. The schools only taught Christianity and not Native American religions. Navajo were against teaching. Eventually, the schools included Indian history and self-esteem.
 20th Century 
In the 20th century, there were more rights for Natives. Politicians were more open to Natives. Woodrow Wilson allowed Natives who fought in World War I to become citizens. Calvin Coolidge signed the Indian Citizenship Act. This made all Natives American citizens. Republican Charles Curtis was a Native and Congressman. He became the Senate Minority Whip and Senate Majority Leader for several years. Today Americans have all the rights of the US constitution. The Indian Relocation Act of 1956 supported vocational training.
Many Natives fought and died in World War II. Soldiers respected the Natives. The legacy of the Native American warrior was still there.
There was also more self-determination for Natives. There was more activism with Natives. Notable events in the 1960s are the occupation of Alcatraz Island (1969–1971) and the formation of the American Indian Movement (AIM). In 1968, the Indian Civil Rights Act gave Natives protection to tribe members. The Indian Self-Determination and Education Assistance Act was passed in 1975. Tribal colleges were created. Many universities have added study programs about Natives Americans. This is partly due to Native activism.
 Contemporary Problems 
Native Americans are affected by some problems more than European Americans. For example Native Americans are six times more likely to suffer from alcoholism than average. About 24% live in extreme poverty. Native American and Native Alaskan women are more likely to be targets of sexual violence than other women. Natives says that they often face prejudice and mistreatment. Many Native Americans live in cities. They face poverty and bad working conditions.
Another problem is cultural appropriation. This is when a culture wrongly adopts and takes elements from another culture. This is a problem in sports with mascots. There are often Native American stereotypes. The Golden State Warriors stopped using Native American logos in the 1970s. In 2020, the Washington Redskins changed their name to Washington Commanders.
There has been controversy with names of Native Americans in the US. Native Americans were historically called Indians. This word has racist stereotypes. The term Native Americans is viewed to be more historically accurate. There is no agreement among Native Americans on what is the best term. Some criticize the term Native Americans, because the government chose it. Several Native tribes prefer the term American Indian. Native Americans prefer to be called by their tribal names.


Mahatma Gandhi: Mohandas Karmchand Gandhi (2 October 1869– 30 January 1948) was a leader of nationalism in British-ruled India. He is more commonly called Mahatma Gandhi. mahatma is an honorific meaning "great-soul" or "venerable" in Sanskrit. He was first called this in 1914 in Africa 
Gandhi on Mahabharata said he wished to live his life like Karna lived Like he sorrows life gave them and how they reacted upon them. You would be able to achieve what human history had never imagined." Gandhi was the Martyr of the Nation since 1948. Rabindranath Tagore gave him the title of 'Mahatma'.
Gandhi was one of the most important people involved in the movement for the independence of India. He was a non-violent activist, who led the independence movement through a non-violent protest.
Early life
Mohandas Karamchand Gandhi was born on 2 October 1869 in Porbander, India. Several members of his family worked for the government of the state. When Gandhi was 18 years old, he went to study law in England. After he became a lawyer, he went to the British colony of South Africa where he experienced laws that said people with dark skin had fewer rights than people with light skin. In 1897, Gandhi was attacked by a group of people in Durban Harbor, South Africa when he was going to work. He went to South Africa because he could not find work in India. When traveling through South Africa, Gandhi was also kicked out of a first class train because of his skin color. Then Gandhi started protesting against segregation. He decided then to become a political activist, so he could help change these unfair laws. He created a powerful, non-violent movement. During Gandhi's life, India was a colony of the British Empire, but wanted independence. He was a huge leader during that era and his thoughts helped catalyze the Indian independence movement.
Gandhi was a vegetarian almost all his life, because he believed in non-violence (ahimsa).
As an activist
On 9 January 1915 when Gandhi returned to India, he decided to again lead a march against a law called the Rowlatt Act. But then the protest turned violent and people started to kill the protesters.
On 12 March 1930 Gandhi led the Salt March.
When he returned to India, he helped cause India's independence from British rule, inspiring other colonial people to work for their independence, break up the British Empire, and replace it with the Commonwealth.
People of many different religions and ethnic groups lived in British India. Many people thought the country should break into separate countries so different groups could have their own countries. In particular, many people thought that Hindus and Muslims should have separate countries. Gandhi was a Hindu, but he liked ideas from many religions including Islam, Judaism, and Christianity, and he thought that people of all religions should have the same rights, and could live together peacefully in the same country.
In 1938, Gandhi resigned from Congress. He said he could no longer work through Congress to unite the divisions in caste and religion. He also felt that he had little to offer to the political process.
On 15 August 1947, the British Indian Empire split into India and Pakistan. Gandhi wanted independence but did not want the former Raj to split into two different countries. Instead of celebrating independence day, he was crying over the end of British India.
Gandhi's principle of satyagraha, often translated as "way of truth" or "pursuit of truth", has inspired other democratic and anti-racist activists like Martin Luther King, Jr. and Nelson Mandela. Gandhi often said that his values were simple, based upon traditional Hindu beliefs: truth (Satya), and non-violence (ahimsa).
Death
On 30 January 1948, he was shot to death by a Brahman activist Nathuram Godse, because Godse thought that Gandhi was too respectful to the Muslims. Godse was tried and executed by Indian officials.


Indian Council for Cultural Relations: The Indian Council for Cultural Relations (ICCR), is an autonomous body working under the aegis of the Ministry of External Affairs (MEA), Government of India, was founded in the year 1950 by Maulana Abul Kalam Azad, independent India’s first Education Minister. 
History
One of the aims of India's freedom struggle was to revive and strengthen the country's cultural ties with the outside world. This was reflected in the historic Asian Relations Conference held in New Delhi in 1946 wherein it was resolved to set up an Indian Council for Cultural Cooperation to revive and promote closer cultural ties with the other Asian Countries and to project the Indian personality and its rich culture through "Indian eyes". The Indian Council for Cultural Relations came to be set up some three years later. However, its scope was not confined to the Asian region alone. Prime Minister of India, Jawaharlal Nehru and Education Minister Maulana Abul Kalarn Azad (who was the Founder President of ICCR from 1950 till 1958) enlarged its mandate to include the task of forging closer cultural ties with the rest of the wide world.
The ICCR was established and formally inaugurated in April 1950. Its objectives as defined in the Memorandum of Association included the following:
 to establish, revive and strengthen cultural relations and mutual understanding between India and other countries.
 to promote cultural exchange with other countries.
 to adopt all other measures as may be required to further its objectives.
Right from its establishment until 1958, the ICCR was under the administrative jurisdiction of the Education Ministry, Government of India. This arrangement continued till 22 April, 1970, when the jurisdiction of the Council was transferred to the Ministry of External Affairs, Government of India, following a decision of the Cabinet Committee on Foreign Affairs. The proposal for the transfer was initiated in 1967 by Shri M.C. Chagla, following his appointment as the Minister of External Affairs from his earlier charge as the Minister of Education.
The Ministry of External Affairs assumed administrative and operational control of the Council in 1970-71 with a view to making the Council an effective instrument of India's foreign policy. In 1978, in keeping with the recommendations of the Asoka Mehta Committee, the Council took over from the Department of Culture all work pertaining to incoming and outgoing cultural delegations and delegated activities relating to implementation of cultural exchange programmes.
In the initial years, the aims and objectives of the ICCR were two-fold:
(a) to project  Indian culture and heritage on the international cultural map and to present India through Indian eyes so as to correct various distortions about India created by established stereotypes of the colonial era;
and
(b) to forge people-to-people contacts with the other countries, particularly the newly emerging nations.
By and large, the ICCR's activities have helped in achieving these broad Objectives.
Aim
The objective of ICCR is to actively participate in the formulation and implementation of policies and programmes pertaining to India’s external cultural relations; to foster and strengthen cultural relations and mutual understanding between India and other countries and to promote cultural exchange with other countries and people.
Locations
The ICCR Headquarter is situated at Azad Bhavan, I.P. Estate, New Delhi. The 38 Cultural Centres and 2 Centres in PPP model in different parts of the world promote awareness of India’s composite cultural heritage abroad. They are under the administrative control of the Council and their respective Indian Missions abroad. Paris and Washington are the new ICCs in the pipeline.
The Indian Cultural Centres (ICCs) are located in Georgetown, Paramaribo, Port Louis, Jakarta, Bali, Kabul, Budapest, Mexico City, Moscow, Berlin, Seoul, Cairo, London (Nehru Centre, London), Tashkent, Almaty, Durban, Port of Spain and Colombo. ICCR has opened new cultural centers in Dhaka, Thimpu, Sao Paulo, Kathmandu, Bangkok, Kuala Lumpur and Tokyo.
They also have zonal and sub-zonal offices in Bangalore, Guwahati, Kolkata, Lucknow, Mumbai, Patna, Pune, Jammu, Ahmedabad, Delhi NCR and Shillong.
Organisation
The activities of ICCR are broadly categorized under three important Heads, (i) Administration & Establishment, (ii) Culture and (iii) Education. 
One of the flagship programmes of ICCR includes offering of 3938 scholarships annually to foreign nationals from approximate 140 countries all over the world, under 26 schemes. Online admissions taking place on the A2A (Admissions to Alumni) portal launched by our EAM in January, 2018 ensures a smooth, efficient and transparent process. 
Towards meeting the primary mandate of the Council to create international understanding through culture, ICCR sponsors hundreds of Indian Outgoing Cultural Delegations (OCD) abroad, both within the ambit of India’s Cultural Exchange programme with different countries and outside it. The Council also hosts Incoming Cultural Delegations (ICD) to promote foreign cultural presentations in the country. In addition, the Council implements cultural projects on behalf of MEA, Ministry of Culture, the Parliament, etc. 
ICCR in consultation with Indian Missions abroad, has established 65 Indian Chairs in various foreign Universities, besides Nelson Mandela Chair in India. It also organises International Conferences under Conferences and Seminar on diverse subjects covering a wide spectrum. 
The ICCR hosts Exhibitions, Distinguished Visitor’s Programme, Academic Visitors Programme, Publication, maintenance of a well-stocked library and the manuscripts of Maulana Abul Kalam Azad, digitisation of rare manuscripts, publication of Gagnanchal (Hindi bi-monthly), promotion of Hindi, presentation of books, art objects and musical instruments to Institutions abroad. 
Besides the Jawaharlal Nehru Award for International Understanding and the Gisela Bonn Award for a German national, the ICCR has also instituted the Distinguished Alumni Award, the Distinguished Indologist Award and the World Sanskrit Award in 2015 respectively, to recognise the contributions of foreign scholars in the field of art, culture and literature. 
ICCR has been vigorously involved in coordinating International Yoga Day (IYD) celebrations at a global scale. The organisation of recently held Kumbh Mela witnessed participation of 186 delegations from 184 countries. ICCR is celebrating 150th birth anniversary of Mahatma Gandhi Ji globally. It is now coordinating the marking of 550th birth Anniversary of Guru Nanak Devji. 
Youth Seminar on “Teachings of Sri Guru Nanak Dev ji and Sikhism Contribution in Universal Well being” was organized by the Council on 6 November 2019 followed by visits to 03 Takhats to Patna, Amritsar and Nanded from 7-10 November 2019. 
The Council organised the first of its kind 2 days conference titled “Destination India-Making India the Preferred Hub of Education” in collaboration with Symbiosis International University and Savitribai Phule Pune University from 28-29 January, 2020 to brain storm ways and strategies of attracting foreign students to India and making India an attractive destination for higher education. The conference was inaugurated by Hon’ble Minister of Human Resource Development and witnessed the participation of reputed Government organisations like UGC, Ministry of Home Affairs, IITs several Art and cultural institutions, etc.
References


Sport psychology: Sport psychology means applying parts of psychology to sports and athletes. One of the main ways that sports psychologists use is to help athletes meet their goals. The main group of people that sports psychologists try to help are professional athletes. They can help non-professional athletes as well. Sports psychologists mainly focus on problems the athlete has on the field but they can also help athletes with problems that they have off the field. Sports psychology did not become a recognized area of study until recently, but it has been used in the past.
 History 
 European history and the beginnings 
Sports psychology began at the end of the nineteenth century in Europe. Sports and the body were now a more important part of people’s lives. During the 1880s, more sports were a part of the lifestyle of the people. But, the word psychology was not used in connection with the word sport before the late 1890s. In 1899 and 1900, the phrase, psychology of sport, appeared in the titles of two journal articles. The first one was by Balduin Groller. It was published in two parts in 1899, in the journal Die Wage under the title “Zur Psychologie des Sportes” (translated About the Psychology of Sport). This article said that there were parts of psychology that had not been researched at that time, that could be connected to sports and physical activities. Then in May 1900, an essay by the founder of the modern Olympic movement, Pierre de Coubertin, was published. It was titled “Le Psychologie du Sport” (translated The Psychology of Sport).
In 1875, Pyotr Francevich Lesgaft started a system of physical education. Lesgaft was a Russian scientist who studied the human body. His aim was to promote harmony between the body and soul or mind. The method Lesgaft suggested was to learn conscious control of the body; being able to think about controlling the body and then actually doing it. Then in 1884-1885, Karoly Budinsky wrote an article called “About Gymnastic Activity and the Development of Will”. The article was about how self-control and willpower could make the nervous system stronger through physical exercise.
Two scientists were at the beginning of European sport psychology: Angelo Mosso and Philippe Tissie. Angelo Mosso was an Italian who studied the human body. He was also interested in using science to study physical education, exercise, and sport. In his experiments, Mosso found that mental work causes weakness of the muscles. He also found that physical work causes weakness in mental performance. In 1894, Mosso conducted an experiment with his brother, Ugolino Mosso. He had ten Italian Mountain soldiers climb to the top of the mountain and live in a hut for ten days. He also had them perform physical exercises. There are two parts of his results that are related to sports psychology. The first one is called the pioneer effect. The pioneer effect is when in mountain climbing, the person who is leading the group will be more tired than all the others. The second is called the rivaling effect. The rivaling effect is when the soldiers, especially in periods of boredom, would begin to compete with each other in their weight lifting tests. Philippe Tissie viewed sports as a way to treat mental disorders. He published several articles between 1894 and 1909. These articles talked about how sports could help people with mental disorders. He thought that a combination of sports, gymnastics, and psychology could help people with mental disorders. He also thought that playing in too many sports could cause people to have mental disorders and behavioral problems.
In 1896, a French doctor named Charles du Pasquier published an article about how sports could help people with depression. In 1900, Eduard Bertz said that sports could help people maintain a healthy body and soul or mind. Later in 1913, Toby Cohn believed sports was a way for people to develop self-confidence, emotional health, and goal orientation. In 1914, Bernhard Berliner conducted the first study on what effect sports and exercise had on the mind and psychology. In his study, he looked at children who exercised and played sports while at a camp. His study found that children who played sports and exercised were able to concentrate better.
The first sports psychology laboratory was opened in 1920 in Berlin, Germany by Carl Diem. That same year, a psychological lab was opened by Robert Werner Schulte at the Deutsche Hochschue fur Leibesubungen near Berlin. This was a college for physical education. The lab was used to study the natural ability that people had for doing good in sports. Schulte also included sports psychology in his talks to students who took physical education. Then in 1921, he published his first book. This book was named Body and Mind in Sport. He then continued to go on to write many books about the topic of sport psychology. One of these books was called Aptitude and Performance Testing in Sport. The next development, in 1926, was the first psychoanalysis of what motivated people to want to play sports. This was done by Helene Deutsch. She found that playing in sports could help people with depression, anxiety and overcoming fears.
There were also major developments to the field of sports psychology that took place in Russia. In 1925, Russian sports psychologist Petr Antonovic Rudik did research on the development of skills and on reaction times. A reaction time is how quickly someone responds to something. In 1926, Alexander Netchayev did research on how perception, memory, imagination, and attention are influenced by sports and physical activities.
 North American history 
Sports psychology in North America began in the 1890s. E. W. Scripture began to study the reaction times of runners in his Yale lab. He also watched how athletes could be helped by experimental psychology. Experimental psychology uses experiments and science to study the brain and the mind. He also wrote papers about how sports affected who a person was. In his papers he argued that prisoners who participated in sports while in jail got a better attitude.
George Wells Fitz was also active in sports psychology at this time. Fitz created the first known physical education lab in North America. In 1895, Fitz ran an experiment. This experiment focused on studying the reaction times of people. He found one thing in his results: people who had quicker and more accurate reaction times would be better at sports. Fitz was the first to run experiments on reaction times in North America.
The next major event in sports psychology was an idea known as transfer of training. Transfer of training happens when you exercise one arm or one side of the body to make it stronger and the other side also becomes stronger without having any exercise. This area was first studied by Walter Wells Davis in the late 1800s. Davis ran an experiment that involved having people lift weights with one arm and not the other. His results proved the theory of transfer of training. William G. Anderson also studied this concept. In his experiments he found that people who squeezed an object on one side of the body also got stronger on the opposite side of the body.
The next developments came from Norman Tripplett. Norman Tripplett worked at the University of Indiana as a psychologist. He conducted an experiment that focused on competition. This experiment started to connect sports and psychology. His experiment also began to combine them into one field. In 1897, Tripplett started his study. He focused on how the performance of one person is influenced by other people being around. In 1898, he wrote about his results in his article, “The Dynamogenic Factors Involved in Pace-making and Competition”. His beliefs and findings were that cyclists were more likely to cycle faster when in the presence of a pacemaker or a competitor. People were more likely to cycle faster because the presence of another person caused them to put in more effort and use energy that they were not before. In 1898, Tripplett tried to confirm his predictions and beliefs he came up with during the cycling study by running an experiment in laboratory. This experiment consisted of people winding fishing line as fast as they could in order to move a flag around a course. The results of this experiment confirmed the results and predictions that were found in the cycling study.
In 1903, G.T.W Patrick studied the psychology of American football and why people loved the game so much. Next in 1912, Howard wanted to discover why people became so emotional while watching sports. Then in 1915, Karl S. Lashley and John B. Watson started a study that focused on the learning curve of people in sports. A learning curve is how people learn the skills they need to in order to succeed in sports. The sport that they focused their study on was archery. The results of their study lead them to argue that when people were participating in harder tasks, like archery, they were more likely to work harder to complete the task.
Sportswriter Hugh S. Fullerton is involved in the next development in the history of sports psychology. Fullerton brought New York Yankees player Babe Ruth to a psychology laboratory at Columbia University. Fullerton brought Ruth there to participate in a study run by Albert Johanson and Joseph Holmes. He wanted Ruth to participate in the study because he wanted to find a reason for why Ruth hit so many home runs. He also wanted to prove to other baseball scouts whether or not other players like Ruth existed. The study that Ruth participated in was used to study sensory-motor performance. Sensory-motor performance is how things that we perceive with our senses influence our movements. The study involved measuring the power of Ruth’s swing, his reaction time, his attention, his memory, and his motor skills. The results of this study offered a reason for why Ruth hit so many home runs. His skill for hitting home runs could be because on the tests his motor skills and reflexes scored above average. The next development that came regarded football. At Stanford University, B.C. Graves, a psychology graduate student, Walter Miles, a professor, and Glenn “Pop” Warner, a college football coach started an experiment. Their experiment studied reaction time. They ran their ran experiment so they could find the fastest way to get the offense to move together when the center hiked the ball. This led to the use of psychology as a way to gain an advantage over your opponent in a competition.
 Coleman Griffith 
Even though there were many developments to this field prior to this point, the most important did not come until the time of Coleman Griffith. Griffith was a professor at the University of Illinois. He is considered to be the father of sports psychology in North America. Griffith's first contribution was that he started a section in his introductory to psychology class that only athletes could take. Then in 1921, he gave the first public talk about psychology and athletics. In 1923, he started a special course focusing on psychology and sports. It was called Psychology and Athletics. The textbook that was used for this class was Griffith’s third book, called Psychology of Coaching. Later in 1924, Griffith began meeting with Knute Rockne, who was a football coach at Notre Dame. He met with Rockne to explore how coaching was affected by psychology.
The next major contribution that Griffith made was in 1925, when he opened the first sports psychology lab in North America. This lab was only able to stay open for six years. After the closure of the laboratory, Griffith was contacted in 1937 by Philip Wrigley. Wrigley was the owner of the Major League Baseball team the Chicago Cubs. He contacted Griffith to offer him a job. Griffith accepted the job. He called the project Experimental Laboratories of the Chicago National League Ball Club. While with the Cubs, Griffith studied how psychological factors influenced performance. Based on the results of his research Griffith made recommendations to Wrigley. These recommendations included psychological clinics for the players, holding fielding practice, and having achievement tests to measure the athletes’ basic skills. However, Wrigley did not follow these recommendations but was still impressed by Griffith’s work. Wrigley offered Griffith a full-time position as a sports psychologist in 1939. Griffith refused the job to stay with his family. After this Griffith did not conduct anymore major research in the area of sports psychology. Griffith was an important part of sport psychology's history. He was an important part because not only was he the first sports psychologist but he also opened the first laboratory in America that studied the relationship between sports and psychology.
 Sports Psychology after Griffith: The 20th century 
In the 1920s and 1930s, psychology was beginning to be taught at coaching schools. Some coaches used what they were learning about sports psychology while coaching their teams. Paul Brown was head coach of the Cincinnati Bengals. He began using psychological testing with his players. His tests eventually became known as the beginning of the National Football League’s tests that are still used today. During the 1940s, psychology was starting to be used as a way for athletes to improve their performance. Psychology professor Dorothy Hazeltine Yates helped a boxer try to improve his skills through psychology; the boxer then went on to have the best fights of his career. Also during the 1940s, hypnosis was starting to be used to help athletes to relax. During the 1950s, David F. Tracy began using psychological methods to help players on the St. Louis Browns, a major league baseball team, now known as the Baltimore Orioles.
In the late 1950s and early 1960s, sports were becoming more important to people. So, psychology of sports was more accepted because it helped athletes. Four things were important to expand the field of sports psychology. These were textbooks, graduate programs, associations, and journals. One of the main areas that was being studied during this time period was the effect stress had on athletes and their performance. In 1960, Warren R. Johnson continued the research he started in 1949. This research was about the effect stress had on an athlete. He continued this research by creating the first textbook on the topic. In 1961, Maxwell Howell started the first graduate school program in physical education. He did this at the University of Alberta in Canada. The creation of associations and journals was the next development of this time period. In 1967, the North American Society for the Psychology of Sport and Physical Activity or (NASPSPA)was created. It was created by a group of sport psychologists led by Warren Johnson. One of the first things that this organization did was to start publishing the "Sport Psychology Bulletin". The "Sport Psychology Bulletin" included research reports and the writings of the members of the NASPSPA. Then in 1970, the "International Journal of Sport Psychology" was started. During the 1970s and 1980s, there were many associations and journals that were started. These were the Association for the Advancement of Applied Sport Psychology, the American Psychological Association's Division 47 of Exercise and Sport Psychology, the Sport Psychology Academy of the American Alliance for Health, Physical Education, Recreation, and Dance, the "Journal of Sports Psychology", the "Journal of Sport Science", the "Sport Psychologist", and the "Journal of Applied Sport Psychology". The next major developments involved the United States Olympic Committee. In 1978, they started a Sports Medicine Council that included sports psychologists. In 1985, they created the first registry or list of sports psychologists.
 Modern sports psychology 
Now there are two types of sports psychology, academic and applied. Academic sports psychology does the research. Applied sports psychology uses that research to teach coaches and trainers. There are three main areas of need in applied sports psychology. They are what kinds of certification, education, or licenses are necessary to practice applied sports psychology, the need to provide proper training for people who are studying applied sports psychology, and developing new ways to help athletes.
Today the number of sports psychologists that are being used by athletes is increasing. In fact, so many athletes are being helped by sports psychologists, that some organizations are starting to limit how many coaches can be on the field during a game. Many athletes are now using sports psychology as part of their everyday lives and training for games.


Article One of the United States Constitution: Constitution of the United States of America#Article I Article One of the United States Constitution
Article One of the United States Constitution establishes the legislative branch of the federal government, the United States Congress. The Congress is a bicameral legislature consisting of a House of Representatives and a Senate
Section 1: Legislative power vested in Congress
Section 1 gives federal legislative power exclusively to Congress. Similar clauses are found in Articles II and III. The former gives executive power to the President. The latter grants judicial power to the federal judiciary. These three articles create a separation of powers among the three branches of the federal government.The Constitution does not explicitly say that the powers of the three branches of the federal government are to be separated. James Madison wanted to add an amendment saying so, but other members of Congress at the time felt that separation of powers was implicit in the Constitution itself. The separation of powers was intended to limit Congress to making law, the President to enforcing the law and the courts as interpreting the law in different cases.
There is no provision in the Constitution that gives Congress the power to investigate. However, before the adoption of the Constitution, assemblies| in the American colonies exercised that power. Before them, the British Parliament had investigative powers. Congress has always considered it an implicit power in the Constitution. In McGrain v. Daugherty (1927), the Supreme Court held that Congress did have the power to investigate.
Section 2Section 2: House of Representatives
Section 2, Clause 1Clause 1: Composition and election of Members
Section Two provides for the election every two years of members of the House of Representatives by the people of the respective states. The "electors" (voters) in the state are those who the state decides are eligible to vote for "the most numerous Branch of the State Legislature" are eligible to vote for members of the House of Representatives from that state.
Section 2, Clause 2Clause 2: Qualifications of Members
The Constitution provides three requirements for Representatives. A Representative must be at least 25 years old. He or she must live in the state in which he or she is elected. A Representative must also have been a citizen of the United States for the previous seven years.
Section 2, Clause 3Clause 3: Apportionment of Representatives and taxes
After much debate, the framers of the Constitution compromised and made population the basis of determining the number of seats (called apportionment) in the House of Representatives. It also used apportionment to determine the tax liability among the states. To accomplish this, the Constitution requires that a census be conducted every ten years. This is to determine the population of each state and of the nation as a whole. It also establishes a rule for who should and who should not be included in the count. Because the Constitution would go into effect before the completion of a national census, it provides for a temporary apportionment of seats in the House of Representatives.
Originally, the population of each state and of the nation as a whole was determined by adding to the whole number of free Persons, three-fifths the number of all other persons (slaves), but excluding non-taxed Native Americans. This Constitutional rule was known as the three-fifths compromise. It was used to determine the number of Representatives in the House. Larger states contributed more money and would have more seats in the House of Representatives. 
The Fourteenth Amendment removed the three-fifths rule and ordered the census to count everyone regardless of skin color. It stipulated that males over the age of twenty-one could vote. The Sixteenth Amendment removed the connection between apportionment and direct taxes. The 19th Amendment removed the restriction by sex allowing women to vote. The 26th Amendment reduced the voting age requirement to those 18 years of age and older. But none of these amendments changed congressional apportionment.
Since enactment of the Reapportionment Act of 1929, Congress set the number of House seats at 435, except in 1959 when Alaska and Hawaii were admitted as states. Then the number became 437 temporarily.
Section 2, Clause 4Clause 4: Vacancies
Section two, Clause four, provides that when vacancies occur in the House of Representatives, it is not the job of the House of Representatives to arrange for a replacement. It is the job of the State whose vacant seat is up for refilling. In addition, the Constitution does not authorize a State Governor to appoint a temporary replacement. He is to arrange for a special election to fill the vacancy. The original qualifications and procedures for holding that election are still valid.
Section 2, Clause 5Clause 5: Speaker and other officers; Impeachment
Section Two also provides that the House of Representatives may choose its Speaker and its other officers. The Constitution does not require it but every Speaker has been a member of the House of Representatives. The Speaker rarely presides over routine House sessions. Instead he chooses to deputize a junior member to accomplish the task.
Finally, Section Two grants to the House of Representatives the sole power of impeachment. Although the Supreme Court has not had an occasion to interpret this specific provision, the Court has suggested that the grant to the House of the "sole" power of impeachment makes the House the exclusive interpreter of what constitutes an impeachable offense.
This power, which is analogous to the bringing of criminal charges by a grand jury, has been used only rarely. The House of Representatives has initiated impeachment proceedings 62 times since 1789, and nineteen federal officials have been formally impeached as a result, including: three Presidents (Andrew Johnson, Bill Clinton, and Donald Trump), one Cabinet Secretary (William W. Belknap), one Senator (William Blount), one Supreme Court Associate Justice (Samuel Chase), and fourteen federal judges.
The Constitution does not specify how impeachment proceedings are to be initiated. Until the early 20th century, a House member could rise and propose an impeachment, which would then be assigned to a committee for investigation. Presently, it is the House Judiciary Committee that initiates the process. It does this only after investigating the allegations, prepares recommendations for the whole House's consideration. If the House votes to adopt an impeachment resolution, the Chairman of the Judiciary Committee recommends a slate of "managers," whom the House subsequently approves by resolution. These Representatives then become the prosecution team in the impeachment trial in the Senate (see Section 3, Clause 6 below).
Section 3Section 3: Senate
Section 3, Clause 1Clause 1: Composition; Election of Senators
The first Clause of Section Three provides that each state is entitled to have two Senators. It states they would be elected by its state legislature and serve six-year terms. Each Senator has one vote. By these provisions, the framers of the Constitution intended to protect the interests of the states as states. However, this clause has been superseded by the Seventeenth Amendment, ratified in 1913. Due to problems in the Senate, it was changed to Senators would now be elected by the people instead of the state legislatures.
Section 3, Clause 2Clause 2: Classification of Senators; Vacancies
Approximately one-third of the Senate is up for re-election every two years. But the entire body is never up for re-election in the same year. The Seventeenth Amendment changed how vacancies would be filled. Under the Seventeenth Amendment, if a Senator dies or has to leave office, his state governor may appoint a temporary Senator until a special election can be held.
Section 3, Clause 3Clause 3: Qualifications of Senators
A Senator must be at least 30 years of age, must have been a citizen of the United States for at least nine years before being elected, and must reside in the State he or she will represent at the time of the election. As with Representatives in the House, the Constitution sets the qualifications to be a Senator.
Section 3, Clause 4Clause 4: Vice President as President of Senate
Section Three provides that the vice president is the President of the Senate. When serving in this capacity, the vice president, who is not a member of the Senate, may cast a vote to break a tie. Early in the nation's history, vice presidents frequently presided over the Senate. In modern times, the vice president usually does so only during ceremonial occasions or when a tie in the voting is anticipated. A tie-breaking vote has been cast 243 times by 35 different vice presidents.
Section 3, Clause 5Clause 5: President pro tempore and other officers
Clause five provides for a President pro tempore of the Senate (meaning temporary), a Senator elected to the post by the Senate, to preside over the body when the Vice President is either absent or exercising the Office of the President.
The Senate's current practice is to elect a full-time President pro tempore at the beginning of each Congress, as opposed to making it a temporary office only existing during the Vice President's absence. Since World War II, the senior (longest serving) member of the majority party has filled this position. As is true of the Speaker of the House, the Constitution does not require that the President pro tempore be a senator, but by tradition, a senator is always chosen.
Section 3, Clause 6Clause 6: Trial of Impeachment
The House of Representatives votes to impeach a president, vice president or other civil officer, but the Senate serves as judge and jury. The defendant in the trial can be removed from office by a two-thirds vote of the Senate. Only three times has the Senate brought impeachment charges against a president still in office. This was in 1868 against Andrew Johnson, in 1998 against Bill Clinton, and in 2020 against Donald Trump. In each case, the president was not convicted and allowed to serve out his term of office.
Section 3, Clause 7Clause 7: Judgment in cases of impeachment; Punishment on conviction
If any officer is convicted on impeachment, he or she is immediately removed from office. He or she may be barred from holding any public office in the future. No other punishments may be used. Any person removed from office may still be criminally prosecuted. They may also be subject to lawsuits. 
Section 4Section 4: Congressional elections
Section 4, Clause 1Clause 1: Time, place, and manner of holding
State legislatures have the task of deciding how congressional elections are held. They may decide the scheduling of an election, where voters may cast ballots and how voters are to register. Congress has the right to change these rules. 
Section 4, Clause 2Clause 2: Sessions of Congress
Clause 2 fixes an annual date upon which Congress must meet. By doing so, the Constitution gives Congress the power to meet, whether or not the President called it into session. 
Section 5Section 5: Procedure
Section 5, Clause 1Clause 1: Qualifications of Members
Section Five states that a majority of each House constitutes a quorum to do business; a smaller number may adjourn the House or compel the attendance of absent members. In practice, the quorum requirement is all but ignored. A quorum is assumed to be present unless a quorum call, requested by a member, proves otherwise. Rarely do members ask for quorum calls to demonstrate the absence of a quorum; more often, they use the quorum call as a delaying tactic.
Section 5, Clause 2Clause 2: Rules
Each House can determine its own Rules (assuming a quorum is present), and may punish any of its members. A two-thirds vote is necessary to expel a member. Section 5, Clause 2 does not provide specific guidance to each House regarding when and how each House may change its rules, leaving details to the respective chambers.
Section 5, Clause 3Clause 3: Record of proceedings
Each House must keep and publish a Journal, though it may choose to keep any part of the Journal secret. The decisions of the House—not the words spoken during debates—are recorded in the Journal; if one-fifth of those present (assuming a quorum is present) request it, the votes of the members on a particular question must also be entered.
Section 5, Clause 4Clause 4: Adjournment
Neither House may adjourn, without the consent of the other, for more than three days. Often, a House will hold pro forma sessions every three days. Such sessions are held just to fulfill the constitutional requirement. They are not for the purpose of conducting business. Neither House may meet in any place other than that designated for both Houses (the Capitol), without the consent of the other House.
Section 6Section 6: Compensation, privileges, and restrictions on holding civil office
Section 6, Clause 1Clause 1: Compensation and legal protection
Senators and Representatives set their own compensation. Under the Twenty-seventh Amendment, any change in their compensation will not take effect until after the next congressional election.
Members of both Houses have certain privileges, based on those enjoyed by the members of the British Parliament. Members attending, going to or returning from either House are privileged from arrest, except for treason, felony or breach of the peace. One may not sue a Senator or Representative for slander that may happen during Congressional debate, nor may speech by a member of Congress during a Congressional session be the basis for criminal prosecution. 
Section 6, Clause 2Clause 2: Independence from the executive
Senators and Representatives may not simultaneously serve in Congress and hold a position in the executive branch. This restriction is meant to protect legislative independence by preventing the president from using patronage to buy votes in Congress. It is a major difference from the political system in the British Parliament, where cabinet ministers are required to be members of parliament.
Section 7Section 7: Bills
Section 7, Clause 1Clause 1: Bills of revenue
This establishes the method for making Acts of Congress that involve taxation. Accordingly, any bill may originate in either House of Congress, except for a revenue bill, which may originate only in the House of Representatives. 
This clause of the U.S. Constitution stemmed from an English parliamentary practice that all money bills must have their first reading in the House of Commons. This practice was intended to ensure that the power of the purse is possessed by the legislative body most responsive to the people, although the English practice was modified in America by allowing the Senate to amend these bills. 
Section 7, Clause 2Clause 2: From bills to law
This clause is known as the Presentment Clause. Before a bill becomes law, it must be presented to the President, who has ten days (excluding Sundays) to act upon it. If the President signs the bill, it becomes law. If he disapproves of the bill, he must return it to the House in which it originated together with his objections. This procedure has become known as the veto, although that particular word does not appear in the text of Article One. The bill does not then become law unless both Houses, by two-thirds votes, override the veto. If the President neither signs nor returns the bill within the ten-day limit, the bill becomes law, unless the Congress has adjourned in the meantime, thereby preventing the President from returning the bill to the House in which it originated. In the latter case, the President, by taking no action on the bill towards the end of a session, exercises a "pocket veto", which Congress may not override. In the former case, where the President allows a bill to become law unsigned, there is no common name for the practice, but recent scholarship has termed it a "default enactment."
What exactly constitutes an adjournment for the purposes of the pocket veto has been unclear. In the Pocket Veto Case (1929), the Supreme Court held that "the determinative question in reference to an 'adjournment' is not whether it is a final adjournment of Congress or an interim adjournment, such as an adjournment of the first session, but whether it is one that 'prevents' the President from returning the bill to the House in which it originated within the time allowed." Since neither House of Congress was in session, the President could not return the bill to one of them, thereby permitting the use of the pocket veto. In Wright v. United States (1938), however, the Court ruled that adjournments of one House only did not constitute an adjournment of Congress required for a pocket veto. In such cases, the Secretary or Clerk of the House in question was ruled competent to receive the bill.
Section 7, Clause 3Clause 3: Presidential veto
In 1996, Congress passed the Line Item Veto Act, which permitted the President, at the time of the signing of the bill, to rescind certain expenditures. The Congress could disapprove the cancellation and reinstate the funds. The President could veto the disapproval, but the Congress, by a two-thirds vote in each House, could override the veto. In the case Clinton v. City of New York, the Supreme Court found the Line Item Veto Act unconstitutional because it violated the Presentment clause. First, the procedure delegated legislative powers to the President, thereby violating the nondelegation doctrine. Second, the procedure violated the terms of Section Seven, which state, "if he approve [the bill] he shall sign it, but if not he shall return it." Thus, the President may sign the bill, veto it, or do nothing, but he may not amend the bill and then sign it.
Every bill, order, resolution, or vote that must be passed by both Houses, except on a question of adjournment, must be presented to the President before becoming law. However, to propose a constitutional amendment, two-thirds of both Houses may submit it to the states for the ratification, without any consideration by the President, as prescribed in Article V.
Section 8Section 8: Powers of Congress
Enumerated powers
Congress's legislative powers are enumerated in Section Eight:
Many powers of Congress have been interpreted broadly. Most notably, the Taxing and Spending, Interstate Commerce, and Necessary and Proper Clauses have been deemed to grant expansive powers to Congress.
Congress may lay and collect taxes for the "common defense" or "general welfare" of the United States. The U.S. Supreme Court has not often defined "general welfare," leaving the political question to Congress. In United States v. Butler (1936), the Court for the first time construed the clause. The dispute centered on a tax collected from processors of agricultural products such as meat; the funds raised by the tax were not paid into the general funds of the treasury, but were rather specially earmarked for farmers. The Court struck down the tax, ruling that the general welfare language in the Taxing and Spending Clause related only to "matters of national, as distinguished from local, welfare". Congress continues to make expansive use of the Taxing and Spending Clause; for instance, the social security program is authorized under the Taxing and Spending Clause.
Congress has the power to borrow money on the credit of the United States. In 1871, when deciding Knox v. Lee, the Court ruled that this clause permitted Congress to emit bills and make them legal tender in satisfaction of debts. Whenever Congress borrows money, it is obligated to repay the sum as stipulated in the original agreement. However, such agreements are only "binding on the conscience of the sovereign", as the doctrine of sovereign immunity prevents a creditor from suing in court if the government reneges its commitment.
Commerce Clause
The Supreme Court has seldom restrained the use of the commerce clause for widely varying purposes. The first important decision related to the commerce clause was Gibbons v. Ogden, decided by a unanimous Court in 1824. The case involved conflicting federal and state laws: Thomas Gibbons had a federal permit to navigate steamboats in the Hudson River, while the other, Aaron Ogden, had a monopoly to do the same granted by the state of New York. Ogden contended that "commerce" included only buying and selling of goods and not their transportation. Chief Justice John Marshall rejected this notion. Marshall suggested that "commerce" included navigation of goods, and that it "must have been contemplated" by the Framers. Marshall added that Congress's power over commerce "is complete in itself, may be exercised to its utmost extent, and acknowledges no limitations other than are prescribed in the Constitution".
The expansive interpretation of the Commerce Clause was restrained during the late nineteenth and early twentieth centuries, when a laissez-faire attitude dominated the Court. In United States v. E. C. Knight Company (1895), the Supreme Court limited the newly enacted Sherman Antitrust Act, which had sought to break up the monopolies dominating the nation's economy. The Court ruled that Congress could not regulate the manufacture of goods, even if they were later shipped to other states. Chief Justice Melville Fuller wrote, "commerce succeeds to manufacture, and is not a part of it."
The U.S. Supreme Court sometimes ruled New Deal programs unconstitutional because they stretched the meaning of the commerce clause. In Schechter Poultry Corp. v. United States, (1935) the Court unanimously struck down industrial codes regulating the slaughter of poultry, declaring that Congress could not regulate commerce relating to the poultry, which had "come to a permanent rest within the State." As Chief Justice Charles Evans Hughes put it, "so far as the poultry here in question is concerned, the flow of interstate commerce has ceased." Judicial rulings against attempted use of Congress's Commerce Clause powers continued during the 1930s.
In 1937, the Supreme Court began moving away from its laissez-faire attitude concerning Congressional legislation and the Commerce Clause, when it ruled in National Labor Relations Board v. Jones & Laughlin Steel Company, that the National Labor Relations Act of 1935 (commonly known as the Wagner Act) was constitutional. The legislation under scrutiny, prevented employers from engaging in "unfair labor practices" such as firing workers for joining unions. In sustaining this act, the Court, signaled its return to the philosophy espoused by John Marshall, that Congress could pass laws regulating actions that even indirectly influenced interstate commerce.
This new attitude became firmly set into place in 1942. In Wickard v. Filburn, the Court ruled that production quotas under the Agricultural Adjustment Act of 1938 were constitutionally applied to agricultural production (in this instance, home-grown wheat for private consumption) that was consumed purely intrastate, because its effect upon interstate commerce placed it within the power of Congress to regulate under the Commerce Clause. This decision marked the beginning of the Court's total deference to Congress' claims of Commerce Clause powers, which lasted into the 1990s.
United States v. Lopez (1995) was the first decision in six decades to invalidate a federal statute on the grounds that it exceeded the power of the Congress under the Commerce Clause. The Court held that while Congress had broad lawmaking authority under the Commerce Clause, the power was limited, and did not extend so far from "commerce" as to authorize the regulation of the carrying of handguns, especially when there was no evidence that carrying them affected the economy on a massive scale. In a later case, United States v. Morrison (2000), the justices ruled that Congress could not make such laws even when there was evidence of aggregate effect.
In contrast to these rulings, the Supreme Court also continues to follow the precedent set by Wickard v. Filburn. In Gonzales v. Raich it ruled that the Commerce Clause granted Congress the authority to criminalize the production and use of home-grown cannabis even where states approve its use for medicinal purposes. The court held that, as with the agricultural production in the earlier case, home-grown cannabis is a legitimate subject of federal regulation because it competes with marijuana that moves in interstate commerce.
Other powers of Congress
Congress may establish uniform laws relating to naturalization and bankruptcy. It may also coin money, regulate the value of American or foreign currency and punish counterfeiters. Congress may fix the standards of weights and measures. Furthermore, Congress may establish post offices and post roads (the roads, however, need not be exclusively for the conveyance of mail). Congress may promote the progress of science and useful arts by granting copyrights and patents of limited duration. Section eight, clause eight of Article One, known as the Copyright Clause, is the only instance of the word "right" used in the original constitution (though the word does appear in several Amendments). Though perpetual copyrights and patents are prohibited, the Supreme Court has ruled in Eldred v. Ashcroft (2003) that repeated extensions to the term of copyright do not constitute perpetual copyright; also note that this is the only power granted where the means to accomplish its stated purpose is specifically provided for. Courts inferior to the Supreme Court may be established by Congress.
Congress has several powers related to war and the armed forces. Under the War Powers Clause, only Congress may declare war, but in several cases it has, without declaring war, granted the President the authority to engage in military conflicts. Five wars have been declared in United States' history: the War of 1812, the Mexican–American War, the Spanish–American War, World War I and World War II. Some historians argue that the legal doctrines and legislation passed during the operations against Pancho Villa constitute a sixth declaration of war. Congress may grant letters of marque and reprisal. Congress may establish and support the armed forces, but no appropriation made for the support of the army may be used for more than two years. This provision was inserted because the Framers feared the establishment of a standing army, beyond civilian control, during peacetime. Congress may regulate or call forth the state militias, but the states retain the authority to appoint officers and train personnel. Congress also has exclusive power to make rules and regulations governing the land and naval forces. Although the executive branch and the Pentagon have asserted an ever-increasing measure of involvement in this process, the U.S. Supreme Court has often reaffirmed Congress's exclusive hold on this power (e.g. Burns v. Wilson, 346 U.S. 137 (1953)). Congress used this power twice soon after World War II with the enactment of two statutes: the Uniform Code of Military Justice to improve the quality and fairness of courts martial and military justice, and the Federal Tort Claims Act which among other rights had allowed military service persons to sue for damages until the U.S. Supreme Court repealed that section of the statute in a divisive series of cases, known collectively as the Feres Doctrine.
Congress has the exclusive right to legislate "in all cases whatsoever" for the nation's capital, the District of Columbia. Congress chooses to devolve some of such authority to the elected mayor and council of District of Columbia. Nevertheless, Congress remains free to enact any legislation for the District so long as constitutionally permissible, to overturn any legislation by the city government, and technically to revoke the city government at any time. Congress may also exercise such jurisdiction over land purchased from the states for the erection of forts and other buildings.
Necessary and Proper clause
Finally, Congress has the power to do whatever is "necessary and proper" to carry out its enumerated powers and, crucially, all others vested in it. This has been interpreted to authorize criminal prosecution of those whose actions have a "substantial effect" on interstate commerce in Wickard v. Filburn ; however, Thomas Jefferson, in the Kentucky Resolutions, supported by James Madison, maintained that a penal power could not be inferred from a power to regulate, and that the only penal powers were for treason, counterfeiting, piracy and felony on the high seas, and offenses against the law of nations.
The necessary and proper clause has been interpreted extremely broadly, thereby giving Congress wide latitude in legislation. The first landmark case involving the clause was McCulloch v. Maryland (1819), which involved the establishment of a national bank. Alexander Hamilton, in advocating the creation of the bank, argued that there was "a more or less direct" relationship between the bank and "the powers of collecting taxes, borrowing money, regulating trade between the states, and raising and maintaining fleets and navies". Thomas Jefferson countered that Congress's powers "can all be carried into execution without a national bank. A bank therefore is not necessary, and consequently not authorized by this phrase". Chief Justice John Marshall agreed with the former interpretation. Marshall wrote that a Constitution listing all of Congress's powers "would partake of a prolixity of a legal code and could scarcely be embraced by the human mind". Since the Constitution could not possibly enumerate the "minor ingredients" of the powers of Congress, Marshall "deduced" that Congress had the authority to establish a bank from the "great outlines" of the general welfare, commerce and other clauses. Under this doctrine of the necessary and proper clause, Congress has sweepingly broad powers (known as implied powers) not explicitly enumerated in the Constitution. However, the Congress cannot enact laws solely on the implied powers, any action must be necessary and proper in the execution of the enumerated powers.
Section 9Section 9: Limits on Congress
The ninth section of Article One places limits on Congress' powers:
Slave trade
The first clause in this section prevents Congress from passing any law that would restrict the importation of slaves into the United States prior to 1808. Congress could however, levy a Per capita duty of up to ten dollars for each slave imported into the country. This clause was further entrenched into the Constitution by Article V, where it is explicitly shielded from constitutional amendment prior to 1808. On January 1, 1808, the first day it was permitted to do so, Congress approved legislation prohibiting the importation of slaves into the United States.
Civil and legal protections
A writ of habeas corpus is a legal action against unlawful detainment that commands a law enforcement agency or other body that has a person in custody to have a court inquire into the legality of the detention. The court may order the person released if the reason for detention is deemed insufficient or unjustifiable. The Constitution further provides that the privilege of the writ of habeas corpus may not be suspended "unless when in cases of rebellion or invasion the public safety may require it". In Ex parte Milligan (1866), the Supreme Court ruled that the suspension of habeas corpus in a time of war was lawful, but military tribunals did not apply to citizens in states that had upheld the authority of the Constitution and where civilian courts were still operating.
A bill of attainder is a law by which a person is immediately convicted without trial. An ex post facto law is a law which applies retroactively, punishing someone for an act that was only made criminal after it was done. The ex post facto clause does not apply to civil matters.
Apportionment of direct taxes
Section Nine reiterates the provision from Section Two that direct taxes must be apportioned by state populations. This clause was also explicitly shielded from constitutional amendment prior to 1808 by Article V. In 1913, the 16th Amendment exempted income taxes from this clause. Furthermore, no tax may be imposed on exports from any state. Congress may not, by revenue or commerce legislation, give preference to ports of one state over those of another; neither may it require ships from one state to pay duties in another. All funds belonging to the Treasury may not be withdrawn except according to law. Modern practice is that Congress annually passes a number of appropriations bills authorizing the expenditure of public money. The Constitution requires that a regular statement of such expenditures be published.
Titles of nobility
The Title of Nobility Clause prohibits Congress from granting any title of nobility. In addition, it specifies that no civil officer may accept, without the consent of Congress, any gift, payment, office or title from a foreign ruler or state. However, a U.S. citizen may receive foreign office before or after their period of public service.
Section 10Section 10: Limits on the States
Section 10, Clause 1Clause 1: Contracts Clause
States may not exercise certain powers reserved for the federal government: they may not enter into treaties, alliances or confederations, grant letters of marque or reprisal, coin money or issue bills of credit (such as currency). Furthermore, no state may make anything but gold and silver coin a tender in payment of debts, which expressly forbids any state government (but not the federal government) from "making a tender" (i.e., authorizing something that may be offered in payment) of any type or form of money to meet any financial obligation, unless that form of money is coins made of gold or silver (or a medium of exchange backed by and redeemable in gold or silver coins, as noted in Farmers & Merchants Bank v. Federal Reserve Bank). Much of this clause is devoted to preventing the States from using or creating any currency other than that created by Congress. In Federalist no. 44, Madison explains that "... it may be observed that the same reasons which shew the necessity of denying to the States the power of regulating coin, prove with equal force that they ought not to be at liberty to substitute a paper medium in the place of coin. Had every State a right to regulate the value of its coin, there might be as many different currencies as States; and thus the intercourse among them would be impeded." Moreover, the states may not pass bills of attainder, enact ex post facto laws, impair the obligation of contracts, or grant titles of nobility.
The Contract Clause was the subject of much contentious litigation in the 19th century. It was first interpreted by the Supreme Court in 1810, when Fletcher v. Peck was decided. The case involved the Yazoo land scandal, in which the Georgia legislature authorized the sale of land to speculators at low prices. The bribery involved in the passage of the authorizing legislation was so blatant that a Georgia mob attempted to lynch the corrupt members of the legislature. Following elections, the legislature passed a law that rescinded the contracts granted by the corrupt legislators. The validity of the annulment of the sale was questioned in the Supreme Court. In writing for a unanimous court, Chief Justice John Marshall asked, "What is a contract?" His answer was: "a compact between two or more parties." Marshall argued that the sale of land by the Georgia legislature, though fraught with corruption, was a valid "contract". He added that the state had no right to annul the purchase of the land, since doing so would impair the obligations of contract.
The definition of a contract propounded by Chief Justice Marshall was not as simple as it may seem. In 1819, the Court considered whether a corporate charter could be construed as a contract. The case of Trustees of Dartmouth College v. Woodward involved Dartmouth College, which had been established under a Royal Charter granted by King George III. The Charter created a board of twelve trustees for the governance of the College. In 1815, however, New Hampshire passed a law increasing the board's membership to twenty-one with the aim that public control could be exercised over the College. The Court, including Marshall, ruled that New Hampshire could not amend the charter, which was ruled to be a contract since it conferred "vested rights" on the trustees.
The Marshall Court determined another dispute in Sturges v. Crowninshield. The case involved a debt that was contracted in early 1811. Later in that year, the state of New York passed a bankruptcy law, under which the debt was later discharged. The Supreme Court ruled that a retroactively applied state bankruptcy law impaired the obligation to pay the debt, and therefore violated the Constitution. In Ogden v. Saunders (1827), however, the court decided that state bankruptcy laws could apply to debts contracted after the passage of the law. State legislation on the issue of bankruptcy and debtor relief has not been much of an issue since the adoption of a comprehensive federal bankruptcy law in 1898.
Section 10, Clause 2Clause 2: Import-Export Clause
Still more powers are prohibited of the states. States may not, without the consent of Congress, tax imports or exports except for the fulfillment of state inspection laws (which may be revised by Congress). The net revenue of the tax is paid not to the state, but to the federal Treasury.
Section 10, Clause 3Clause 3: Compact Clause
Under the Compact Clause, states may not, without the consent of Congress, keep troops or armies during times of peace. They may not enter into alliances nor compacts with foreign states, nor engage in war unless invaded. States may, however, organize and arm a militia according to the discipline prescribed by Congress. (Article I, Section 8, enumerated powers of Congress.) The National Guard, whose members are also members of the militia of the United States as defined by 10 311, fulfill this function, as do persons serving in State Militias with federal oversight under 32 109.
The idea of allowing Congress to have say over agreements between states traces back to the numerous controversies that arose between various colonies. Eventually compromises would be created between the two colonies and these compromises would be submitted to the Crown for approval. After the American Revolutionary War, the Articles of Confederation allowed states to appeal to Congress to settle disputes between the states over boundaries or "any cause whatever". The Articles of Confederation also required Congressional approval for "any treaty or alliance" in which a state was one of the parties.
There have been a number of Supreme Court cases concerning what constitutes valid congressional consent to an interstate compact. In Virginia v. Tennessee, 148 503 1893, the Court found that some agreements among states stand even when lacking the explicit consent of Congress. (One example the court gave was a state moving some goods from a distant state to itself, it would not require Congressional approval to contract with another state to use its canals for transport.) According to the Court, the Compact Clause requires congressional consent only if the agreement among the states is "directed to the formation of any combination tending to the increase of political power in the States, which may encroach upon or interfere with the just supremacy of the United States". The congressional consent issue is at the center of the current debate over the constitutionality of the not yet effective National Popular Vote Interstate Compact entered into by several states plus the District of Columbia.


Democratic Party (United States): Democratic Party
The Democratic Party, also known as the Democrats, is one of the two biggest political parties in the United States. Since the mid-1850's, the party's main opponent has been the Republican Party. Both political parties have controlled American politics ever since.
Overview
The party sits at the center to center-left of the American political spectrum, with the Republican Party being positioned to their right.
Every four years, the party holds a National Convention where they agree on their candidate for president. The Democratic National Committee coordinates most of the activities of the Democratic Party in all 50 United States. Since Andrew Jackson's inauguration in 1829, there have been 16 Democratic presidents. The most recent is Joe Biden who took office as the 46th president of the United States in January 2021. The Democratic Party represents a broad spectrum of liberal and left-wing ideologies, including but not limited to classical liberalism, social democracy, progressivism, and social modern liberalism.December 2024
Philosophy
Democrats, also sometimes called the left, liberals or progressives make up one of the two main political parties in the United States. A mostly Democratic state is sometimes called a blue state. This comes from the party’s main color, which is blue, referring to a state supporting "blue" candidates.
Role of government
Democrats believe in a strong government with social assistance programs to help members of society. They prefer diplomatic solutions to conflicts, and take generally multilateralist views on trade, believing that trade must be free, but fair to protect American workers, consumers, local communities, and the environment. Some Democrats are economic centrists.
Social issues
Socially, most Democrats believe in sociocultural liberalism, taking pro-immigration, pro-marriage equality, and pro-choice views.
Beliefs
Currently, the Democratic Party is identified by progressivism, liberalism, and left-wing policies. Not all Democrats hold the same beliefs, but generally these are the things many Democrats support:
 Progressive income tax
 Higher corporate taxes and recapturing income from overseas profits
 Spending on business, education, infrastructure and clean energy
 Expanding spending on government programs
 Ending the death penalty
 Expanding rights to abortion
 Gun regulations to prevent citizens from hurting themselves and others with firearms
 Support same-sex marriage
 Universal healthcare
 Declare Washington D.C. an official state
 Helping students go to college or university for free without having to pay back the government
 Believe in allowing undocumented immigrants to work for their U.S Citizenship in the U.S. to stay, pay taxes, and oppose mass deportation
Most support for Democrats comes from states in the Northeast, Upper Midwest, and the Pacific Coast, as well as from the state of Hawaii.
Symbols
The symbol of the Democratic Party is the donkey. Since the election of 2000, the color blue has become a symbol for Democrats.
Historically, Thomas Jefferson, whom the party claims as its founder, has been often seen as symbols of the Democratic Party, particularly emphasized in the annual celebrations of Jefferson Day Dinners held since the days of Andrew Jackson. As such, the Democratic Party is also often referred to as the “Party of Jefferson.”
List of Democratic presidents
Select list of Democratic politicians
 Kamala Harris (California), Vice President and U.S. Senator from California
 John Kerry (Massachusetts), former Secretary of State, former Senator, former presidential nominee
 Patrick Leahy (Vermont), former President Pro Tempore, Senator, and Dean of the Senate
 Hillary Clinton (New York), former Secretary of State, former Senator, former First Lady, former presidential nominee
 Jim Clyburn (South Carolina), Representative and Assistant Democratic Leader
 Howard Dean (Vermont), former Governor and former head of the Democratic National Committee, former presidential nominee 
 Christopher Dodd (Connecticut), former Senator
 Mario Cuomo (New York), former Governor
 Dick Durbin (Illinois), Senate Whip
 George Moscone (California), former Mayor of San Francisco
 Chuck Schumer (New York), Senator, former Senate Majority Leader
 Harvey Milk (California), Member of the San Francisco Board of Supervisors
 William M. Daley (Illinois), candidate for Governor of Illinois, former White House Chief of Staff
 Frank Lautenberg (New Jersey), former Senator
 Pat Quinn, Governor of Illinois
 Paul Simon (Illinois), former Senator
 Arlen Specter (Pennsylvania), former Senator
 Bob Menendez (New Jersey), Senator
 Richard M. Daley (Illinois), former Mayor of Chicago
 Richard J. Daley (Illinois), former Mayor of Chicago
 Al Gore (Tennessee), former presidential candidate and vice-president
 John F. Kennedy, former President (Massachusetts)
 Robert F. Kennedy, former Senator, former presidential candidate, and brother of John F. Kennedy
 Daniel Inouye (Hawaii), former President Pro Tempore, former Senator, and former Dean of the Senate
 Steny Hoyer (Maryland), House Minority Whip
 Robert Byrd (West Virginia), former President Pro Tempore, former Senator, and former Dean of the Senate
 Tim Kaine (Virginia), Governor, 2016 vice presidential nominee and former head of the Democratic National Committee
 Dennis Kucinich (Ohio), Representative
 Janet Napolitano (Arizona), Secretary of Homeland Security
 Nancy Pelosi (California), Speaker of the House, former Speaker of the House.
 Brian Schweitzer (Montana), former Governor
 Harry Reid (Nevada), former Senate Minority Leader, former Majority Leader 
 Rahm Emanuel (Illinois), Mayor of Chicago, former White House Chief of Staff
 Harry F. Byrd, Jr. (Virginia), former Senator
 Bill Richardson (New Mexico), Governor
 Debbie Wasserman Schultz (Florida), Representative and former head of the Democratic National Committee
 Mark Warner (Virginia), Senator and former Governor
 Elizabeth Warren, Senator from Massachusetts
 Alexandria Ocasio-Cortez (New York), Representative
 Hakeem Jeffries, House Minority Leader
Independents who work with Democrats
 Bernie Sanders, Senator from Vermont
 Angus King, Senator from Maine
List of former Democrats
 Ronald Reagan (California), 40th president of the United States (1981–1989). Registered Democrat until 1962.
 Condoleezza Rice (Alabama), 66th United States Secretary of State (2005–2009). Registered Democrat until 1982.
 Rudy Giuliani (New York), 107th Mayor of New York City (1994–2001). Registered Democrat until 1975.
 Rick Perry (Texas), 14th United States Secretary of Energy (2017–2019), 47th Governor of Texas (2000–2015). Registered Democrat until 1989.
 Jesse Helms (North Carolina), United States Senator (1973–2003). Registered Democrat (1942–1970).
 Donald Trump (New York), 45th and 47th President of the United States (2017–2021), (2025–present) Registered Democrat on and off until 2009.


Capital punishment in the United States: Capital punishment has existed in the United States before it became a country. As of 2021, capital punishment is legal in 27 out of 50 states. The federal government and the United States military have capital punishment.
The United States is the only Western country that has capital punishment.
History
Colonial America
Virginia
Before the United States became an independent country, it was a colony of the British Empire. The first known death sentence in colonial America happened in 1608. Captain George Kendall was executed by firing squad at the Jamestown colony after being accused of spying for the Spanish government.
In colonial America, people could be executed for many things. In the Jamestown colony, the first set of rules and punishments the colony's Lieutenant Governor wrote was very strict. There were 48 different capital crimes (crimes that were punishable by death). They included:
 Picking flowers from a neighbor's garden
 Criticizing the British government (for the third time)
 Blasphemy (for the third time)
 Trading with Native Americans (for the first time)
 Leaving the colony (for the third time)
 Stealing food because of hunger (for the third time)
When some colonists decided they did not like these strict rules, they ran away from the colony to live with nearby Native Americans. They were brought back to the colony, tortured, and executed.
The Thirteen Colonies
Each of the Thirteen Colonies came up with its own death penalty laws. For example, in the Massachusetts Bay Colony, which was mostly Puritan, laws were harsh. Under its first capital punishment laws, which were effective from 1636-1647, people were executed for sodomy, adultery, witchcraft, blasphemy, bestiality, assault, rape, statutory rape, perjury in a capital trial, and murder. Later, the colony continued to execute people for witchcraft, including 20 people during the Salem Witch Trials. They also executed people for being Quakers and pirates.
Under the New York colony's Duke's Laws of 1665, a person could be executed for "denial of the one true God" or for hitting their mother or father.
Some colonies were not as strict. For example, the New Jersey colony had no death penalty, and in the Pennsylvania colony only murder and treason were capital crimes.
Revolutionary War era
By 1776, most of the colonies had similar laws about the death penalty. In most colonies, the capital crimes were arson, piracy, treason, murder, sodomy, burglary, robbery, rape, stealing horses, slave rebellion, and counterfeiting (making fake money). Usually, people sentenced to death were hanged.
During the American Revolutionary War, British Major John André was hanged by the Continental Army on October 2, 1780. He was convicted of spying and helping Benedict Arnold.
Slaves
The first slaves were brought to the Jamestown colony in 1619. Slavery was legal in the United States for the next 246 years, until the Thirteenth Amendment to the United States Constitution made it illegal in 1865. Until that time, slaves had no rights.
Slaves could be punished or tortured for any reason, or for no reason at all. Slaves who tried to escape or rebel were often tortured and executed where other slaves could see, to warn them not to do the same thing.
For example, in 1755, in the Massachusetts Bay Colony, a slave named Mark was accused of poisoning his "master." He was executed, then hung in chains at Boston Harbor so his body would rot. This was supposed to remind other slaves not to rebel every time they passed Mark's body.The Massachusetts Bay Colony, and other colonial cities by the ocean, also used this punishment on pirates. The goal was to warn other pirates who might be sailing by what the punishment would be if they were caught. Twenty years later, when Paul Revere made his "Midnight Ride," Mark's skeleton was still hanging in chains at Boston Harbor.
During the 1700s, in the Southern colonies, an unknown number of slaves were executed, sometimes for things like hitting another slave, "fussing," or "sassing" a white person. Laws in the Southern colonies were passed allowing cruel and unusual punishments as well as capital punishment for slaves.
Reforms
In the late 1700s, activists like Benjamin Rush began to argue that the death penalty should not be used. Between 1794 and 1815, eight states passed laws that made fewer crimes punishable by death. However, many southern states made more crimes punishable by death, especially for slaves.
Major reforms started to happen between 1833 and 1853. At that time, many executions were public events. By 1849, fifteen states had switched to private hangings.
Abolition
In 1846, Michigan became the first state to abolish the death penalty, just after it entered the United States.
In 1852, Massachusetts's state legislature voted to allow the death penalty only for first-degree murder. The next year, Wisconsin outlawed capital punishment. In 1887, Maine's state legislature banned the death penalty.
The focus on the death penalty slowed while the country was busy with the issue of slavery and the American Civil War. However, in 1897, the United States Congress passed a law that made fewer federal crimes punishable by death. In 1911, Minnesota abolished capital punishment. Several other states also abolished the death penalty, but would start using it again later.
Between 1957 and 1973, six other states permanently abolished the death penalty:
 Alaska and Hawaii, in 1957, before they became states
 Iowa, Vermont, and West Virginia, in 1965
 North Dakota, in 1973
Furman v. Georgia
In 1972, the Supreme Court of the United States ruled in Furman v. Georgia that the way death penalty laws were written made them unconstitutional. They ruled that sentencing rules were discriminatory, because black people got sentenced to death more often than whites for the same crimes. Because of this, the death penalty was cruel and unusual punishment, which violated the Eighth and Fourteenth Amendments to the Constitution. This ruling stopped all executions in the country. Between 1972 and 1976, there were no executions in the United States.
However, by early 1975, thirty states had passed new death penalty laws that they thought would satisfy the Supreme Court. They did. In Gregg v. Georgia (1976), the Supreme Court ruled that Georgia's new death penalty law was constitutional. It ruled that capital punishment was not always cruel and unusual punishment, as long as it was done fairly. This meant that states could start executing people again, as long as they had rewritten their death penalty laws like Georgia did, to say that the death penalty would be applied fairly. In 1977, executions began again in the United States.
Limitations
In two major cases, the Supreme Court has limited who may be executed. In Atkins v. Virginia (2002), the Court decided that executing people with intellectual disabilities is cruel and unusual punishment, and is against the Eighth Amendment. Before this decision, between 1984 and 1992, forty-four people with intellectual disabilities were executed in the United States.
Also, in Roper v. Simmons (2005), the Supreme Court made it illegal to execute a person who was younger than 18 when they committed their crime.
Number of executions
In 2004, two researchers named M. Watt Espy and John Ortiz Smykia put together a list of executions that became known as "The ESPY File." The Espy File says that between 1608 and 1991, in the American colonies and then the United States, 15,269 people were executed. The Espy File is "the most often cited and used list of America's legal executions." However, in a 2011 study, two researchers criticized The Espy File. They wrote that researchers should not use the File as a complete source of information about executions.
According to the United States Department of Justice, between 1930 and 2002, the United States executed 4,679 people. About two-thirds of these people (about 3,100 people) were executed between 1930 and 1950.
Between 1916 and 1955, the United States military executed 135 soldiers. The military has not executed anyone since 1955.
In 2016, only 5 of 50 or 10% of US states had executions. They were Alabama, Florida, Georgia, Missouri and Texas.
Methods
Throughout American history, different methods of execution have been used. During colonial times, cruel and painful methods like burning or crushing people to death were sometimes used. However, since 1776, all but a few executions have been carried out in one of five ways: hanging, firing squad, the electric chair, the gas chamber, or lethal injection.
Since the Bill of Rights was added to the United States Constitution in 1791, "cruel and unusual punishment" has been against the law in the United States. This means that even if a person commits a terrible crime, the Constitution says their punishment cannot be painful or cause suffering on purpose.
Hanging
Until the beginning of the 20th century, hanging was the most common method of execution in the United States.
However, hanging did not always work the way it was supposed to. If the rope and noose were not put in the correct position, a person could be decapitated. If the rope was not long enough, the person could slowly die of strangulation. People started looking for more 'civilized' ways to execute people.
Electric chair
After Thomas Edison discovered direct current (DC) electricity in 1882, his company showed how powerful it was by using it to kill animals. The idea of using electricity to kill humans grew out of this. New York built the first electric chair, and first used it to execute a prisoner on August 6, 1890. Other states also adopted the electric chair as a method of execution, believing that it was a less painful way to die than hanging.
However, it became clear, even to some members of the Supreme Court, that dying in an electric chair was very painful. Also, even up until the 1990s, electric chairs would work incorrectly, causing prisoners to catch fire or be awake while they were being electrocuted. Around the 1980s, most states began to use lethal injection instead.
Gas chamber
Still looking for a more "humane" methods of execution, in 1924, Nevada prison officials tried to secretly pump cyanide gas into death row prisoner Gee Jon's cell to kill him while he slept. This did not work, and they had to build a gas chamber. On February 8, 1924, Jon became the first person to be executed by gas chamber.
From 1924 to 1972, the United States executed about 600 people in gas chambers. Most states used hydrogen cyanide gas. However, by the mid-1970s and 1980s, many people had started to criticize the use of gas chambers. Death from hydrogen cyanide poisoning can be long and painful, and in some executions, prisoners suffered long deaths. After one of these executions, a federal court in California ruled that "execution by lethal gas under the California protocol is unconstitutionally cruel and unusual punishment."
Also, according to sociologist Clifton Bryant, the way it is used in the United States, "the gas chamber is ... the most dangerous, most complicated, and most expensive method of administering the death penalty." By the late 20th century, most states had switched to using lethal injection.
Lethal injection
In the 1970s, Oklahoma passed the first law that allowed executions by lethal injection. This was a practical decision: Oklahoma's old electric chair would need expensive repairs, and building a gas chamber would cost over $200,000. However, executing a person by lethal injection would only cost $10 to $15 per person. Lethal injection grew more and more popular in death penalty states. It was viewed as less painful, with less suffering, than the electric chair or gas chamber. Texas was the first state to execute someone by lethal injection, in 1982. Over the next 30 years, all of the death penalty states passed laws making lethal injection their first-choice (or only) method of execution.
However, in the 2010s, American prisons started having trouble getting enough of the medications used to carry out lethal injections. The states had been using three medications for lethal injections:
 Sodium thiopental (an anesthetic to put the prisoner to sleep)
 Pancuronium bromide (to paralyze the prisoner)
 Potassium chloride (to stop the prisoner's heart)
Then, in 2011, Hospira, the only American company that made sodium thiopental, stopped making the drug. The European Union makes other anesthetics, like propofol. However, since the European Union is against the death penalty, they made it illegal to export any product that could be used in an execution. Another anesthetic, pentobarbital, is also only made in the European Union, and the company that makes it has put limits on selling it to U.S. government customers. A few states have tried mixtures of other drugs, but those executions have not gone well.
As of 2016, many death penalty states have temporarily stopped using lethal injection until they can find a solution to this problem.
Other options
As of January 1, 2016, fifteen states have laws that allow them to use a method of execution other than lethal injection. Before the lethal injection drug shortages, these other methods were rarely used. From 1976 to March 23, 2016, there were 1,431 executions:
 1,256 (88%) were by lethal injection
 158 (11%) were by electric chair
 11 (0.8%) were by gas chamber 
 3 (0.2%) were by hanging
 3 (0.2%) were by firing squad
However, since they stopped being able to get lethal injection drugs, some states have thought about going back to other methods of execution. Here are the states whose laws allow them to use other methods, as of January 1, 2016:
Laws
This table shows the death penalty laws in 49 of the 50 states; Washington, D.C.; the federal government; and the United States military, as of January 1, 2016. Under the category "Status," there are four possibilities:
 Abolished. This state no longer uses the death penalty.
 Legal. This state still uses the death penalty.
 Moratorium. This means the death penalty law has been temporarily stopped.
 De facto moratorium. This means the death penalty is still officially legal. However, the state has not executed anyone in at least five years (except for people who ask to be executed).
Click on the little triangle at the top of each header box to sort the information in this table by a certain category.
Sentencing
In some areas, prosecutors ask for the death penalty, and judges grant the death penalty, more often than in other areas. Also, once people are convicted and are on "death row," how quickly they are executed depends on the state they are in. On average, in 2004, death penalty states had executed about 10% of the people on their "death rows." However, California had executed only 1% of its prisoners who are sentenced to death. Texas executed 40% of theirs.
Among races
One of the controversies about the death penalty is whether it is given unequally to people of different races.
In a report in 1983, David Baldus and others wrote a famous report that looked at whether the death penalty was applied equally to people of different races in Georgia. They found that:
 People are more likely to be sentenced to death for killing whites than for killing blacks
 Black defendants are more likely to get the death penalty than whites
In 1987, the Supreme Court decided a case called McCleskey v. Kemp. McCleskey's lawyers showed that in Georgia, where McCleskey lived, black people convicted of killing whites were four times more likely to get the death penalty than people convicted of killing non-whites. The Supreme Court accepted this, but ruled against McCleskey. They wrote: "[inequalities] in sentencing are an inevitable part of our criminal justice system." Since then, judges have not allowed lawyers to argue that racial bias plays a part in the death penalty.
Anti-death penalty groups like Amnesty International say:
 As of 2003, African Americans made up 41% of death row inmates, but only 12.6% of the United States population
 34% of the people executed since 1976 have been African American
 About the same number of blacks and whites are murdered. However, 80% of the people executed since 1977 were convicted of murdering white people
The United States Department of Justice says that between 1980 and 2008, African Americans committed 52.5% of the murders in the United States; whites committed 45.3%; and Native Americans and Asians committed 2.2%. This means African Americans are less likely to be executed on a per capita basis. The Department of Justice also says that as of 2009, Hispanic or Latino people make up 17.4% of the United States population, but only 13.5% of death row prisoners.
A 2012 study found that non-white soldiers in the United States military are twice as likely as white soldiers to be given the death penalty. Of the 16 soldiers the military has sentenced to death between 1985 and 2012, 10 (62.5%) were non-whites, one of the study's authors said.
Among sexes
The death penalty is definitely given much more often to men than women. As of October 1, 2014:
 98.12% of the people currently on death row are men (2,978 men); 1.88% (57) are women
 98.92% of the people executed since 1976 have been men (1,374 men); 1.08% (15) have been women
Exoneration
The University of Michigan Law School keeps a list of people who have been exonerated from death row. The list counts "exonerations" as cases where "a person who has been convicted of a crime is officially cleared based on new evidence of innocence."
According to the list, between 1989 and 2015, 116 people have been exonerated from death row. The most common reasons why these people were exonerated were:Some people were exonerated for more than one reason.
 The person was convicted at least partly because police, prosecutors, judges, or other government officials abused their power (88 people were exonerated at least partly for this reason. This is about 76% of the 116 exonerated people.)
 Somebody lied in court or lied when they accused the person of the crime: (85 people 73%)
 The person was convicted based on forensic evidence that was wrong, exaggerated, not proven to be good science, or was fake: 32 people (28%)
 The person's lawyer gave the person an "inadequate legal defense" (the lawyer did not give the person even a basic defense, or made very serious errors during the trial): 31 people (27%)
DNA evidence proved that 25 of these people about 22% were innocent of the crimes they were sentenced to death for.
Of the 116 people who were exonerated, 62 (about 53%) were black, 43 (37%) were white, 9 (8%) were Hispanic, and two were members of other races (2%). In the 88 cases where a government official abused their power, 51 of the exonerated people (about 58%) were black; 29 were Caucasian (33%); and 8 (9%) were Hispanic. Seventeen of the 31 people who received an "inadequate legal defense" (about 55%) were black; 12 (about 39%) were white; and two (about 6%) were Hispanic.
Arguments
The death penalty is a very controversial topic in the United States. People have argued about it since before the Thirteen Colonies became the United States. There are many different arguments for and against the death penalty. This list does not include all of them, just some of the most common ones.
Possibility of mistakes
People who do not agree with the death penalty (death penalty opponents) say our trial system is not perfect. Judges and juries make mistakes. One study done by Columbia Law School found that there were serious mistakes in two-thirds of all capital trials. In these trials, the defendants were sentenced to death anyway. However, when their cases were appealed, over 80% of the defendants were not sentenced to death; 7% were found not guilty.
Opponents argue that because mistakes are so common in capital trials, people can be executed even though they were innocent. As proof, they point the 116 people who were exonerated from death row between 1989 and 2015.
People who support the death penalty (death penalty supporters) say that mistakes are very rare, especially since new laws were made in the 1970s to add protections for death row inmates. For example, Steve Stewart, Deputy Prosecuting Attorney for the Clark County, Indiana, Fourth Judicial Court, says:
Preventing other crimes
Death penalty supporters say that capital punishment is a deterrent. This means that people are scared of the death penalty and are less likely to commit a capital crime if they know they could get the death penalty.
Supporters also argue that the next most serious punishment for capital crimes is life in prison. In some states, this means the person could be let out of prison someday. Also, even being in prison for life does not keep killers from killing more people in prison. Executing people is the only way to make sure they will never kill another person.
Opponents argue that nobody has ever proved that capital punishment is more of a deterrent than a long prison sentence. They point out that most states and countries that do not have the death penalty have lower murder rates than death penalty states. They also say that the death penalty is not a deterrent because people often commit murders when they are very upset and are not thinking about what might happen in the future.
Among scholars and researchers, there is no agreement about whether capital punishment is more of a deterrent than any other punishment. Some researchers have done studies that say the death penalty is a deterrent. Other studies have found that the death penalty is not a deterrent in the United States, or in other countries.
Whether the death penalty is applied unfairly
Opponents argue that defendants who are poor and/or non-white are more likely to get the death penalty than whites, even if they have committed the same crimes. Supporters say that opponents misuse statistics and exaggerate the situation. For more information, see the section on Sentencing: Among races farther up on this page.
Whether the death penalty is cruel and unusual punishment
Death penalty debaters argue about whether capital punishment is "cruel and unusual punishment" (which would be unconstitutional). Even the people on the Supreme Court have disagreed on this issue. In 2004, the Court ruled in Baze v. Rice that even if an execution causes pain, that does not make it cruel and unusual. However, in his dissenting opinion in Gregg v. Georgia, Justice William Brennan wrote that the death penalty is "an unusually severe punishment, unusual in its pain... [it] is today a cruel and unusual punishment prohibited by the ... Eighth and Fourteenth Amendments."
The American Civil Liberties Union (ACLU), an anti-death penalty group, adds that capital punishment is "unusual" because:
 The United States is the only western nation that uses the death penalty; and
 Only a very small number of murderers in the United States get the death penalty.
Morals and religions
Religion plays a complicated role in death penalty arguments. To support the death penalty, some people quote from the Old Testament of the Bible, which says: "An eye for an eye, a life for a life." This means that if you take a life, you should pay with your own life. However, others use parts of the New Testament, where Jesus talks about forgiveness and nonviolence, to oppose the death penalty. They say that no one has the right to take a life but God even if that person has taken a life himself.
In 1999, a group of Jewish rabbis and Catholic Bishops had this to say:
Opponents also point out:
Graphs and charts


Artificial intelligence: March 2025
Artificial intelligence (AI or A.I.) is a computer program or a machine that is able to learn and mimic human cognition. Sometimes, AI is used to talk about neural networks or deep learning.
Artificial intelligence is a system's ability to understand external data, to learn from that data, and to use what it has learned to achieve specific goals or tasks through adaptation.
Artificial intelligence is widely applied in speech recognition, image recognition, robotics, autonomous systems, natural language processing, machine translation, predictive analytics, medical diagnostics, fraud detection, and the control of physical processes.
 Origin of name 
John McCarthy came up with the name, "artificial intelligence" in 1956. Intelligence allows an organism to act in a meaningful way in its environment. It includes the ability to get sensory inputs, and to react to these.
 Laws 
The European Union made a law (2024's second quarter) about artificial intelligence. It is the world's first law that regulates AI.
Connecticut and Colorado tried to pass laws (in 2024) regarding use of AI.
 History 
AI research started with a conference at Dartmouth College in 1956. It was a month-long brainstorming session many people who like AI came to. At the conference, they wrote programs which were able to beat humans at checkers or solving word problems. The Department of Defense started giving a lot of money to AI research, and labs were created all over the world.
In a paper on AI, mathematician James Lighthill wrote "no aspect of the discipline has so far seen discoveries generated the huge influence that was previously anticipated In no part of the field have the discoveries made so far produced the major impact that was then promised.". The governments of the US and UK decided to spend money on other projects which caused little new research to be done. This was known as an "AI winter."
In the 90s and early 2000s, AI became important again in data mining and medical diagnosis. This was possible because of faster computers and focusing on solving more specific problems. In 1997, the chess computer Deep Blue became the first computer program to beat chess world champion Garry Kasparov. In 2011, IBM Watson beat the top two Jeopardy! players Brad Rutter and Ken Jennings. In 2016, Google's AlphaGo beat top Go player Lee Sedol 4 out of 5 times.
The idea is perhaps much older. Julien Offray de La Mettrie (1709-1751) was a materialist thinker of the Enlightenment. In his work of 1748, L'Homme Machine, he had the idea that both matter and life organized themselves. He is seen as one of the precursors of Darwin's theory of evolution. Today, one field of artificial intelligence, called strong artificial intelligence wants to build a machine that can think like a person. However, weak artificial intelligence is about building a system that can support a human. One of the key problems is to make systems that can model wikt:uncertainity. Most of the time, this is done with probability theory and statistics.
 Uses 
Artificial intelligence is used in many different areas today.
 Healthcare (see Artificial intelligence in healthcare) AI helps doctors diagnose diseases and find treatments for patients.
Industry-specific tasks; AI applications are used to solve problems in a workplace, industry, or institutions.
 Finance: Banks use AI to find fraud and make trading decisions.
 Customer service: Many companies use AI chatbots to answer customer questions and provide support.
 Personal assistants: AI assistants like Siri and Alexa help people manage their daily tasks.
 Entertainment: AI is used in video games to create smart, responsive characters and stories that change in fun ways based on what the player does. AI is used to create videos now-a-days by using different models like Sora.
Those subjects are part of Game artificial intelligence.
Military (Military artificial intelligence)
Generative AI (or Generative artificial intelligence)
Some software has become well-known, such as ChatGPT (a chatbot and virtual assistant).
 Domains 
There are different domains of artificial intelligence.
 Pattern recognition like speech, writing, and handwriting
 Knowledge engineering like logic programming and inference engines
 Expert systems for question answering and Chatbots
 Machine learning
 Artificial neural networks and deep learning
 Computer vision
 Robotics
 General game playing
 Artificial life
Types and classes
Researchers Kaplan and Haenlein say there are three types of AI system: analytical, human-inspired, and humanized artificial intelligence. 
Analytical A.I. has similarities with cognitive intelligence which tries to understand the world and make decisions based on that.
Human-inspired A.I. which tries to be more "human" with cognitive intelligence with emotional intelligence. 
Humanized A.I. is able to understand human social activity and is able to be self aware
Controversies
In 2025, a municipality in Norway made a report in regard to permanently closing down schools; The report used ghost source (or fictitious sources); Those sources were claimed to be the works of two (named) professors; The municipality admitted that the report was made [partly] by A.I.; The process of closing down schools, has stopped (as of March). An official that was involved, resigned (or left her job) one month later. (See Hallucination, artificial intelligence)
Other information
A.I. chips are a kind of computer chip, according to media.
Researchers didn't know how difficult several issues were. They still couldn't offer computers things like emotions or common sense.
Faster computers, deep learning, and more data have made AI popular throughout the world. 
An great intelligent machine is flexible and perceives what is around it. It would use what it learns to make its chance of success at some goal better.
AI has been successful with decoding human speech, playing games (like chess and Go), self-driving cars, and understanding complex data.
Someday, AI researchers hope to create computer programs that can learn, solve problems, and think logically. So far, most AI programs only do what computers can do well like searching databases or doing calculations. AI is not able to sense and understand what is happening around itself because of problems with what computers can do.
AI involves many different fields like computer science, mathematics, linguistics, psychology, neuroscience, and philosophy. Researchers hope to make a "general artificial intelligence" which can solve many problems instead of focusing on just one. Researchers are also trying to make creative and emotional AI which could create art. Alan Turing wrote in 1950 "I propose to consider the question 'can machines think'?"Turing 1950 1 He said the question should be changed from if a machine "thinks" to "whether or not it is possible for machinery to show intelligent behavior".Turing 1950 1 Alan Turing also created the Turing test. This is a very general test. If a human cannot tell if at the other end of the line, there is a machine or a human answering questions, the machine is intelligent.
The authors of Artificial Intelligence: A Modern Approach agree with Turing that AI must be defined by "acting" and not "thinking".Russell Norvig 2021 chpt. 2 But they don't think the test compares machines to people. "Aeronautical engineering texts do not define the goal of their field as making 'machines that fly so exactly like pigeons that they can fool other pigeons.Russell Norvig 2021 3 AI founder John McCarthy agreed, writing that "Artificial intelligence is not, by definition, simulation of human intelligence".Maker 2006
Computers can do some things like learning and problem solving, but not in the same way as people do.
Interestingly, advancements in AI have expanded its applications, including the use of Large language models (LLMs) to "humanize" AI-generated text. This reflects a growing interest in bridging the gap between machine outputs and human-like expression. 
AI and machine learning technology is used in applications including: search engines, recommendation systems, virtual assistants, autonomous vehicles, automatic language translation, facial recognition, image labeling, advertising, and driving internet traffic.
One interesting use of AI is in helping people with their personal relationships. For example, ChatGPT is a powerful AI tool that can create human-like text and assist in many communication tasks.
Optical character recognition is no longer thought of as an example of "artificial intelligence" since it's now commonly used.


Conservative Revolution: February 2025February 2025
The Conservative Revolution (German: Konservative Revolution), also called the German neoconservative movement or new nationalism, was a political movement in Germany and Austria from 1918 to 1933, between World War I and the rise of the Nazis. It was a national-conservative and ultraconservative movement that opposed modern ideas and wanted a different future for Germany.
The people in this movement, called conservative revolutionaries, unaccepted traditional Christian conservatism, democracy, and equality. They felt lost in the modern world and looked to older ideas from the 19th century. These included Friedrich Nietzsche’s dislike of Christian values and democracy, the anti-modern ideas of German Romanticism, the nationalist beliefs of the Völkisch movement, and the strong military traditions of Prussia. Many were also influenced by their experiences of war and comradeship during World War I.
The Conservative Revolution had a complicated connection with Nazism. Some historians see it as a form of early fascism, though it was not exactly the same as Nazism. Unlike the Nazis, it did not always focus on race, but it shared anti-democratic ideas that helped prepare German society for Nazi rule. When Hitler took power in 1933, the movement lost its influence. One of its key thinkers, Edgar Jung, was killed by the Nazis in 1934. Some members later opposed parts of Nazi rule, except for figures like Carl Schmitt.
Since the 1960s and 1970s, the Conservative Revolution has influenced right-wing political movements in Europe, especially in France and Germany. It has also helped shape the modern European Identitarian movement.
 Name and meaning 
Although conservative writers from the Weimar Republic, like Arthur Moeller van den Bruck, Hugo von Hofmannsthal, and Edgar Jung, called their political movement the "Conservative Revolution,"Woods 1996 1–2 the term became popular again after Armin Mohler's doctoral thesis in 1949.Feldman 2006 304 Mohler's post-war ideas about the "Conservative Revolution" have faced a lot of criticism, but many scholars now accept the concept of a "neo-conservative"Dupeux 1994 471–474 or "new nationalist" movement that was active during the Weimar years (1918–1933). This period sometimes includes the 1890s to 1910s and is seen as different from the 19th-century "old nationalism."
Some modern historians find the term "Conservative Revolution" confusing and suggest using "neo-conservative" instead. Sociologist Stefan Breuer suggested the term "new nationalism" to describe a dynamic and inclusive cultural movement that was distinct from the previous century's nationalism, which mainly aimed to maintain German institutions and their global influence. Despite seeming contradictions, Moeller van den Bruck's writings justify the connection between "Conservative" and "Revolution" by defining the movement as a desire to keep enduring values while also adapting ideals and institutions to address the challenges of modern life.Giubilei 2019 2
Historian Louis Dupeux, who studies the Conservative Revolution, viewed the movement as a thoughtful effort with its own clear logic. This effort aimed for 'intellectual power,' using modern techniques and ideas to promote conservative and revolutionary beliefs against liberalism, equality, and traditional conservatism. This shift in view, compared to 19th-century conservatism, is called 'affirmation' by Dupeux: Conservative Revolutionaries embraced their time as long as they could revive what they saw as 'eternal values' in modern society. Dupeux acknowledged that the Conservative Revolution was more of a counter-culture than a real philosophical idea, relying on 'feelings, images, and myths' rather than scientific reasoning. He also recognized the need to identify different views within its various beliefs.
Conservative Revolutionaries are, indeed, as politically reactive as their predecessors, but they display optimism—or at least a strong will—towards the modern world. They no longer fear the masses or technology. This change in attitude has led to significant effects—replacing past regrets with youthful energy—and has sparked broad political and cultural actions.— Louis Dupeux, 1994
Political scientist Tamir Bar-On describes the Conservative Revolution as a mix of extreme German nationalism, support for close-knit communities, modern technology, and a changed version of socialism. It saw workers and soldiers as examples for a new authoritarian state, moving beyond the perceived decline caused by liberalism, socialism, and traditional conservatism.Bar-On 2011 333
 Origin and development 
The Conservative Revolution is part of a bigger movement against the French Revolution of 1789, shaped by early 19th-century Romanticism's dislike for modern ideas and reason. This is seen especially in Germany and Prussia, where there was a strong military, authoritarian nationalism that opposed liberalism, socialism, democracy, and international cooperation.Woods 1996 1–2 Historian Fritz Stern described these people as confused thinkers caught in deep 'cultural despair'; they felt lost in a world controlled by what they considered 'middle-class reasoning and science'. Stern notes that their anger at modernity led them to mistakenly believe that all these modern problems could be solved by a 'Conservative Revolution'.Stern 1961
Terms like Konservative Kraft ('conservative power') and schöpferische Restauration ('creative restoration') became common in German-speaking Europe from the 1900s to the 1920s. The Konservative Revolution ('Conservative Revolution') became a recognized idea in the Weimar Republic (1918–1933) thanks to writers like Arthur Moeller van den Bruck, Hugo von Hofmannsthal, Hermann Rauschning, Edgar Jung, and Oswald Spengler.Klapper 2015 13–15
Alfred Hugenberg started the Alldeutscher Verband ("Pan-German League") in 1891 and the Jugendbewegung ("youth movement") in 1896. These helped the rise of the Conservative Revolution in the years that followed.Dupeux 1994 474–475 Moeller van den Bruck was the main leader of this movement until he took his own life on May 30, 1925. His ideas were first shared through the Juniklub he created on June 28, 1919, the day the Treaty of Versailles was signed.Dupeux 1994 474–475
Conservative Revolutionaries often called German philosopher Friedrich Nietzsche their mentor and saw him as the main thinker behind their movement. Even though Nietzsche's ideas are often misunderstood or misused by these thinkers, they kept his dislike for Christian morals, democracy, modern ways, and equality as key parts of their beliefs. Historian Roger Woods says that Conservative Revolutionaries created a version of Nietzsche who supported bold actions, strong self-assertion, conflict over peace, and trusting instincts more than reason.Woods 1996 57–58
Many thinkers in the movement were born in the late 1800s and saw WWI as a key event that shaped their political ideas.Breuer 1993 21 Their harsh experiences on the front line made most of them look for meaning in what they went through during the war.Woods 1996 1–2, 7–9 Ernst Jünger is a key figure in the Conservative Revolution, which aimed to maintain military values in peacetime and believed that the brotherhood among soldiers showed the real spirit of German socialism.
 Main thinkers 
As noted by Armin Mohler and other sources, key figures in the Conservative Revolution were:
 Ideology 
The German Conservative Revolution, as explained by historian Roger Woods' idea of the "conservative dilemma,"Woods 1996 59–60 can be characterized by its opposition to:
 the traditional conservative values of the German Empire (1871–1918), which include Christian equality; the push to restore the old Wilhelmine empire along its past political and cultural lines;Woods 1996 1–2
 the political system and business culture of the Weimar Republic; and democracy in general, because the national community should go beyond the usual left-right divide;Woods 1996 61–62
 the class ideas of socialism, defending an anti-Marxist "socialist revisionism,"Bar-On 2011 333 which Oswald Spengler called the "socialism of the blood" and was inspired by the brotherhood seen in World War I.Woods 1996 1–2
 New nationalism and morality 
Oswald Spengler, who wrote The Decline of the West, represented a cultural pessimism that partly defined the Conservative Revolution. Conservative Revolutionaries believed their nationalism was different from earlier forms of German nationalism or conservatism.Klapper 2015 13–15 They criticized traditional Wilhelmine conservatives for being backward and not fully grasping new ideas of the modern era, like technology, cities, and the working class.Woods 1996 61
Moeller van den Bruck described the Conservative Revolution as the intention to keep a set of values connected to a Volk (people). These lasting values could endure through changing times due to innovations in how they are organized and understood. Unlike the rigid reactionaries, who don’t create anything, and the pure revolutionaries, who only destroy, the Conservative Revolutionary aimed to shape things in a lasting way that ensures their survival:de Benoist 2014
Conserving is not just about passing down what we received, but about updating the structures and ideas to stay rooted in strong values, even with ongoing historical challenges. In an age of uncertainty, opposing the past is not enough; we must create new security by embracing the same risks that come with it. — Arthur Moeller van den BruckBalistreri 2004
Edgar Jung didn't accept the idea that true conservatives wanted to "stop history." The life they wanted to create, according to Oswald Spengler, was not based on any moral rules, but on "a clear, natural morality from good upbringing." This morality wasn't developed through thought, but was more like an instinct that has its own reasoning.Spengler 1923 891, 982 Conservative revolutionaries viewed moral values as natural and timeless, and they believed these were reflected in rural life. Spengler argued that this rural way of life was threatened by the city's artificial nature, which required theories and ideas to understand life, either from liberal democrats or scientific socialists. The goal of Conservative Revolutionaries was to bring back what they viewed as natural laws and values in the modern world:Woods 1996 103
We call Conservative Revolution the return of essential laws and values, without which humans lose their ties to Nature and God and can't create real order. — Edgar Jung, 1932Jung 1932 380
Influenced by Nietzsche, many opposed Christian ideas of helping each other and equality. Although a lot of Conservative Revolutionaries identified as Protestant or Catholic, they believed Christian principles forced the strong to help the weak when it should be a choice. On a global level, movement thinkers imagined a world where nations would ignore moral rules in their dealings with each other, following only their own interests.Woods 1996 1–2
Let thousands, even millions, die; how does their suffering matter compared to a state that absorbs all the worries and desires of the German identity! — Friedrich Georg Jünger, 1926.
The Völkischen were part of a racial and occult movement from the mid-19th century that affected the Conservative Revolution. They focused on opposing Christianity and wanted to return to a (reconstructed) German pagan belief or change Christianity to remove non-German (Semitic) influences.
 Volksgemeinschaft and dictatorship 
Thomas Mann thought that during World War I, Germany's military resistance to the West was stronger than its spiritual resistance. He believed this was mainly because the character of the German national community couldn't easily express itself in words, which made it hard to effectively challenge the strong arguments from the West. Since German culture was seen as a matter of the soul, not just something the mind could understand,Mann 1968 22–29 Mann believed the authoritarian state was what the German people naturally wanted. He argued that politics was always tied to democracy and therefore did not fit the German spirit.Woods 1996 102
There is no real democratic or conservative politician. You are either a politician or you are not, and if you are, you are a democrat. — Thomas Mann, 1915Mann 1968 22–29
Some scholars have argued whether these ideas are artistic and idealistic, or if they are a serious effort to analyze the politics of the time. Young Mann's writings have strongly influenced many Conservative Revolutionaries.Kroll 2004 In 1922, the right criticized Mann for softening his undemocratic views after he removed parts from his book, Betrachtungen eines Unpolitischen ('Reflections of a Nonpolitical Man'), first published in 1918. In a speech in the same year, 'On the German Republic', Mann openly supported the Weimar Republic and criticized figures linked to the Conservative Revolution, like Oswald Spengler, whom he called dishonest and immoral. In 1933, he called National Socialism the 'political reality of that Conservative Revolution.'
In 1921, Carl Schmitt wrote his essay Die Diktatur ('The Dictatorship'), where he examined the basics of the newly created Weimar Republic. He compared the strong and weak parts of the new constitution and pointed out that the role of the Reichspräsident was important, mainly because Article 48 gave the president the power to declare a state of emergency, which Schmitt quietly supported as a dictatorial power.Agamben 2005
 If a state's constitution is democratic, then any rejection of democratic rules and any use of state power without the majority's approval can be seen as dictatorship.— Carl Schmitt, 1921
Schmitt argued in Politische Theologie (1922) that a legal system cannot work without a supreme authority. He described sovereignty as the ability to declare a "state of emergency," which means setting aside the usual laws: "If there is someone in a government who can completely pause the law and then use outside legal means to restore order, that person is the sovereign in that government."Vinx 2010 He believed that every government should have in its rules the power to act quickly and effectively without needing long discussions in parliament.Agamben 2005 52–55 In 1934, he referenced Adolf Hitler to explain the actions taken during the Night of the Long Knives, stating: Der Führer schützt das Recht ('The leader defends the law').Schmitt 1934
 Front-line socialism 
Socialists generally agreed on getting rid of the worst parts of capitalism. Jung said that, while the economy should stay private, the greed of capital needs to be kept in check, and a community based on shared interests should be created between workers and employers. Another reason for dislike of capitalism was the profits made from war and inflation. Finally, many Conservative Revolutionaries were from the middle class, which made them feel trapped in the struggle between the wealthy capitalists and the threatening masses.Woods 1996 62–63
Even though they didn't accept communism as just a dream, many relied on some Marxist terms in their writings. For example, Jung highlighted the 'inevitable history' of conservatism replacing the liberal age, similar to the historical materialism of Karl Marx. Spengler discussed the decline of the West as an unavoidable trend, but he aimed to offer readers a 'new socialism' that would help them understand the meaninglessness of life, unlike Marx's vision of a paradise on earth. Mostly, the Conservative Revolution was influenced by vitalism and irrationalism, not materialism. Spengler believed Marx's materialist view came from nineteenth-century science, while the twentieth century would focus on psychology.
We don't believe reason has power over life anymore. We think life is what controls reason.— Oswald Spengler, 1932Spengler 1932 83–86
Ernst Niekisch, along with Karl Otto Paetel and Heinrich Laufenberg, was a key supporter of National Bolshevism, a small part of the Conservative Revolution seen as the 'left-wing of the right.' They promoted an extreme form of nationalism mixed with socialism, rejecting all Western influences on German culture, including liberalism, democracy, capitalism, Marxism, the middle class, the working class, Christianity, and humanism. Niekisch and the National Bolsheviks were even willing to team up temporarily with German communists and the Soviet Union to destroy the capitalist West.
 Currents 
In his PhD thesis guided by Karl Jaspers, Armin Mohler identified five groups within the Conservative Revolution: the young conservatives, the national revolutionaries, the folkish group, the leaguists, and the rural people's movement. Mohler noted that the last two groups focused more on action than on theory, with the rural movement providing direct resistance through protests and tax boycotts.Mohler 1950
French historian Louis Dupeux identified five divisions within the Conservative Revolutionaries. Small farmers differed from cultural pessimists and 'pseudo-moderns', mainly from the middle class. Supporters of an 'organic' society were different from those favoring an 'organized' society. A third division separated those who wanted major political and cultural changes from those who wanted a quick social revolution, even at the expense of economic freedom and private property. The fourth division focused on the 'drive to the East' and how to view Bolshevik Russia, debating Germany's position between a 'declining' West and a 'young and barbaric' East. The last division was a strong disagreement between the Völkischen and pre-fascist thinkers.Dupeux 1992
In 1995, historian Rolf Peter Sieferle talked about five groups in the Conservative Revolution: the 'völkischen', the 'national socialists', the 'revolutionary nationalists', the 'vital-activists', and a smaller group called the 'biological naturalists'.Sieferle 1995 25
Using earlier research by Mohler and Dupeux, French political scientist Stéphane François outlined the three key trends in the Conservative Revolution, which is the most common division among those studying the movement:
 the "young conservatives" (Jungkonservativen);
 the "national revolutionaries" (Nationalrevolutionäre);
 the Völkischen (from the Völkisch movement).
 Young conservatives 
"Young conservatives" were greatly affected by 19th-century ideas and styles like German romanticism and cultural pessimism. Unlike older Wilhelmine conservatives, the Jungkonservativen wanted to help bring back important and basic values—authority, the state, the community, the nation, and the people—while also being in tune with their time.Dupeux 1994 471–474
Moeller van den Bruck attempted to solve the issue of Kulturpessimismus by opposing decline to create a new political system.François 2009 In 1923, he published the important book Das Dritte Reich ('The Third Reich'), where he moved from theory to propose a practical plan to improve the political situation: a 'Third Reich' that would bring all classes together under a strict government that mixed right-wing nationalism and left-wing socialism.Klapper 2015 13–15
The Jung Conservatives didn't accept both a nation-state made up of one group of people and an imperial system based on various ethnic groups. Their goal was to achieve the Volksmission ("mission of the people") by creating a new Reich, meaning "the uniting of all peoples in a larger state, led by one guiding principle, under the main control of just one people," according to Armin Mohler.Mohler 1950 Edgar Jung summarized this in 1933:
 The idea of the nation-state is moving personal beliefs from people to the state itself. [...] The super-state (the Reich) is a type of government that operates above the people and can keep them separate. However, it does not aim to be completely controlling and will acknowledge local powers and independence.— Edgar Jung, 1933
Even though Moeller van der Bruck took his own life in May 1925 due to despair, his ideas still affected people of his time. One of them was Edgar Jung, who pushed for a corporatist state without class struggles or parliamentary democracy, aiming to bring back the spirit of the Middle Ages with a new Holy Roman Empire in central EuropeFrançois 2009. The idea of returning to medieval values and styles among 'young conservatives' came from a Romantic love for that time, which they saw as simpler and more united than today. Oswald Spengler admired medieval chivalry as the right way to stand against the decline of modern times.Spengler 1923 891, 982 Jung viewed this change as a slow process, much like the Protestant Reformation of the 16th century, rather than a sudden uprising like the French Revolution.Klapper 2015 13–15
 National revolutionaries 
Other conservative revolutionaries were influenced by their experiences during the First World War. Unlike the 'young conservatives' who worried about culture, Ernst Jünger and the national revolutionaries fully accepted modern techniques and used tools like propaganda and mass groups to overcome modern challenges and create a new political system. This system would be based on real life rather than just ideas, built on natural and structured communities, and led by a new group of capable leaders. Historian Jeffrey Herf called this idea 'reactionary modernism', which means having excitement for modern technology while rejecting Enlightenment ideas and liberal democracy.Herf 1986
That time is only worth wasting. But to waste it, you must understand it first. [...] You had to fully commit to the method, by mastering it in the end. [...] The tool itself was not worthy of praise — that was the risky part — it just needed to be used.— Franz Schauwecker, 1931
Jünger supported the rise of a new group of young intellectuals that would come from the trenches of WWI, ready to challenge capitalist society and represent a fresh nationalist revolutionary spirit. In the 1920s, he wrote over 130 articles in different nationalist magazines, mainly in Die Standarte or, less often, in Widerstand, the publication linked to Ernst Niekisch. However, as Dupeux noted, Jünger wanted to use nationalism as something powerful but not final, allowing the new order to develop on its own.François 2009 The connection between Jünger and the Conservative Revolutionaries is still debated among scholars.
Germany joined the League of Nations in 1926, which helped push the revolutionary side of the movement to become more extreme in the late 1920s. This was viewed as a sign of Western influence in a country that Conservative Revolutionaries imagined as the future Empire of Central Europe.Dupeux 1994 474–475
 Völkischen 
The word völkisch comes from the German idea of Volk (similar to the English word folk), which includes meanings of 'nation', 'race', and 'tribe'. The Völkisch movement started in the mid-1800s and was influenced by German Romantic ideas. It was based on the idea of Blut und Boden ('blood and soil') and was about race, popular feelings, farming, romantic nationalism, and antisemitism from the 1900s. Armin Mohler said that the Völkischen wanted to fight against 'desegregation' that was seen as a threat to the Volk by helping people become aware of their identity.Mohler 1950 81–83, 166–172
Inspired by writers like Arthur de Gobineau, Georges Vacher de Lapouge, Houston Stewart Chamberlain, and Ludwig Woltmann, the Völkischen developed a view of races that put Aryans (or Germans) at the top of the 'white race'. They used phrases like 'Nordic race' and 'Germanic peoples', but their idea of Volk could also mean a 'common language' or an 'expression of a landscape's soul', according to geographer Ewald BanseBanse 1928 469. The Völkischen romanticized the idea of an 'original nation', which they believed could still be found in rural Germany, structured as a form of 'primitive democracy led by their natural leaders.' For the Völkischen, the idea of 'people' (Volk) became a living and eternal being, similar to how they might write about 'Nature', instead of just a sociological group.Dupeux 1992 115–125
The political unrest after WWI created a good environment for the comeback of various Völkisch groups that were common in Berlin then.François 2009 The Völkischen became important by the number of groups during the Weimar Republic, even though they did not have many followers.François 2009 Some Völkischen aimed to bring back what they thought was a true German religion by bringing back the worship of ancient German gods.Boutin 1992 264–265 Different occult movements like Ariosophy were linked to Völkisch ideas, and there were also many artists among them, such as painters Ludwig Fahrenkrog and Fidus.François 2009 By May 1924, Wilhelm Stapel saw the movement as able to unite the entire nation: he believed the Völkischen had a vision to promote instead of a political plan, and they were led by 'heroes' not 'calculating politicians.'
Mohler mentioned these people as part of the Völkisch movement: Theodor Fritsch, Otto Ammon, Willibald Hentschel, Guido von List, Erich Ludendorff, Jörg Lanz von Liebenfels, Herman Wirth, and Ernst Graf zu Reventlow.Mohler 1950 81–83, 166–172
 Relationship to Nazism 
Even though they share significant intellectual ideas, this separate movement cannot be directly compared to Nazism.Woods 1996 111–115 Their anti-democratic and militaristic views definitely helped make the idea of an authoritarian government accepted by some educated middle-class people and youth, but the writings of Conservative Revolutionaries did not strongly shape National Socialist beliefs.Stern 1961 298 Historian Helga Grebing points out that whether people were open to National Socialism is not the same as understanding its roots and ideas.Woods 1996 2–4 This unclear connection has led some experts to describe the movement as a kind of 'German pre-fascism'Dupeux 1992 or 'non-Nazi fascism'.
In the 1920s to early 1930s, as the Nazi Party became powerful, some thinkers, as historian Roger Woods notes, failed to see the true nature of the Nazis. Their political problems and inability to clearly describe a new German government meant there were no strong alternatives from the right, leading to little resistance against the Nazis taking control.Woods 1996 134 Historian Fritz Stern adds that many conservative revolutionaries, even with doubts about Hitler's tactics, viewed him as their only chance to succeed. However, after Hitler's rise, many of Moeller's supporters lost faith, and the twelve years of the Third Reich showed a split between conservative revolution and national socialism.Stern 1961 296–297
A few months after their big election win, the Nazis didn't accept Moeller van den Bruck and claimed he was not a predecessor of National Socialism. They called his ideas 'unrealistic' and said in 1939 that they had 'nothing to do with actual history or practical politics' and that Hitler 'was not Moeller's heir.'Stern 1961 298 Conservative Revolutionaries often had mixed feelings about the Nazis,Bullivant 1985 66 but many turned against Nazism and the Nazi party after they took power in 1933. Some opposed its totalitarian and antisemitic nature, while others would have preferred a different kind of authoritarian regime. Stern summed up the relationship like this:
But we must ask, could there have been another 'Third Reich'? Can we reject reason, praise force, foresee the time of the empire's dictator, and condemn all current systems, without paving the way for the success of irresponsibility? The German critics did all this, showing the serious risks of politics based on cultural hopelessness.— Fritz Stern, 1961Stern 1961 298
 Opponents 
Many Conservative Revolutionaries opposed liberalism and supported the idea of a 'strong leader,' but they did not agree with the totalitarian or antisemitic aspects of the Nazi regime. Martin Niemöller, who initially backed Adolf Hitler, opposed the Nazis’ control over German Protestant churches in 1934 and their Aryan Paragraph. Although he made some comments about Jews that some scholars view as antisemitic, he led the anti-Nazi Confessing Church.
We chose to stay quiet. We are not innocent, and I keep thinking, what if in 1933 or 1934—there must have been a chance—14,000 Protestant pastors and all Protestant groups in Germany had stood up for what was right until the end? What if we had spoken out then, saying it was wrong for Hermann Göring to put 100,000 Communists in concentration camps to let them die?— Martin Niemöller, 1946
Rudolf Pechel and Friedrich Hielscher openly challenged the Nazi government, while Thomas Mann fled in 1939 and sent anti-Nazi speeches to Germany through the BBC during the war. Ernst Jünger turned down a position in the Nazi Reichstag both in 1927 and 1933, hated the "blood and soil" idea, and his home was searched multiple times by the Gestapo. Hermann Rauschning and Gottfried Reinhold Treviranus found safety abroad to continue opposing the regime. Georg Quabbe refused to work with the Nazis as a lawyer. Just before he died in 1936, Oswald Spengler predicted that "in ten years, a German Reich probably won’t exist anymore." In his private writings, he strongly criticized Nazi anti-Semitism.
Anti-Semitism often hides a lot of jealousy towards what others can do that one can't. [...] When someone would rather ruin businesses and education than accept Jews in those areas, they are being extreme, which is harmful to society. Foolish.— Oswald Spengler
Others like Claus von Stauffenberg stayed in the Reichswehr and later the Wehrmacht to quietly plot the July 20th attempt to remove Hitler in 1944. Fritz Stern noted that it showed the real spirit of the conservative movement that the conditions of the Third Reich led many of them to oppose it, sometimes quietly, often openly and at great cost. [...] In the last attempt against Hitler in July 1944, a few former conservative revolutionaries risked and lost their lives, becoming martyrs for the true beliefs they once had.
 Competitors 
Some Conservative Revolutionaries did not completely disagree with the fascist rule of the Nazis, but they wanted a different kind of strict government. Many of them were killed or put in prison for not following Hitler's leadership rule or Führerprinzip.
Edgar Jung, an important leader of the Conservative Revolution, was killed during the Night of the Long Knives by Heinrich Himmler's SS. The SS wanted to stop other nationalist ideas from challenging Hitler. After this event, many Conservative Revolutionaries stopped having mixed feelings about the Nazis. Jung believed that nations were like living beings, criticized individualism, and supported war and strong military power. He also wanted to fully use people and industries and liked modern ideas, similar to Italian Fascism.
Ernst Niekisch did not like Jews and supported a strong government, but he was against Hitler because he thought Hitler was not truly socialist. Instead, he admired Joseph Stalin's leadership. Because he criticized the government, he was sent to a concentration camp from 1937 to 1945.
August Winnig first supported the Nazis in 1933 but later opposed them because of his neo-pagan beliefs. In 1937, he wrote an essay that defended fascism and included antisemitism, but it did not fully match Nazi ideas about race. Since he remained quiet during Hitler’s rule, the Nazis mostly ignored him.
 Collaborators 
Known as the main lawyer of the Third Reich, Carl Schmitt did not regret his part in making the Nazi state even after 1945.Vinx 2010 While he thought Adolf Hitler was too crude, Schmitt took part in burning books by Jewish writers, celebrating the destruction of things he saw as un-German and anti-German, and asking for a bigger cleanup that included writers influenced by Jewish ideas. 
Hans Freyer was the leader of the German Institute for Culture in Budapest from 1938 to 1944. Along with Nazi historian Walter Frank, Freyer created a racist and anti-Jewish history during this time. Wilhelm Stapel joined the Deutsche Christen in July 1933 and strongly opposed the anti-Nazi Confessing Church led by Martin Niemöller and Karl Barth. He also supported the introduction of the Aryan paragraph in the Church. At the same time, Stapel worked with Reichsminister of Church Affairs Hanns Kerrl as his advisor. However, due to pressure from the Nazi leaders in 1938, he had to stop publishing his monthly magazine Deutsches Volkstum.
 Study and debate 
The early study of the Conservative Revolution began with the French historian Edmond Vermeil, who wrote an essay in 1938 called Doctrinaires de la révolution allemande 1918–1938 ("Doctrinarians of the German Revolution 1918–1938").François 2009 In the years right after WWII, many of the political thinkers who focused on the Conservative Revolution were far-right individuals strongly influenced by thinkers like Armin Mohler and Alain de Benoist. It wasn't until the 1980s and 1990s that research on this movement started to gain more attention across different political views, mainly because of its links to Nazism and its impact on the post-war European New Right.Woods 1996 1–2
 Post-war revival after Armin Mohler 
The modern idea of a "Conservative Revolution" was formed after WWII by philosopher Armin Mohler in his 1949 doctoral thesis, titled Die Konservative Revolution in Deutschland 1918–1932, supervised by Karl Jaspers. Mohler referred to Conservative Revolutionaries as the "Trotskyites of the German Revolution" and has often been accused of trying to reshape a pre-WWII far-right movement to fit a post-fascist Europe by downplaying the role of these thinkers in the rise of Nazism. The work was called "a handbook" and, according to historian Roger Griffin, was meant as a guide for those wanting to keep their values in today's world. Mohler thought the "Conservative Revolution" project had just been delayed by the Nazis taking power. At that time, he was also the secretary for Ernst Jünger, a key figure in the movement.Merlio 2003 125
In the 1970s, thinkers from the Conservative Revolution influenced new radical right movements, like the French Nouvelle Droite, led by Alain de Benoist.François 2017 Some scholars, mainly in West Germany, started to question Mohler's work due to his political ties to the idea. The reactionary and anti-modern aspects of the 'Conservative Revolution' were mainly highlighted during that decade, and many viewed the movement as just a breeding ground for Nazism, sharing similar totalitarian views.
German-American historian Fritz Stern used the term "Conservative Revolution" in his 1961 book The Politics of Cultural Despair to describe the life and ideas of Arthur Moeller van den Bruck. He highlighted the feelings of disconnection and "cultural despair" these writers had in the early modern world, which pushed them to share radical ideas. However, Stern placed Moeller van den Bruck within a bigger "Germanic ideology" that included earlier thinkers from the late 19th century like Paul de Lagarde and Julius Langbehn.Stern 1961
 Academic research since the 1980s 
In a 1981 meeting called "Conservative Revolution and Modernity", French historian Louis Dupeux noted that what Mohler called the "Conservative Revolution" was not really reactionary or completely against modern ideas (some were even hopeful about the modern world).Dupeux 1994 471–474 Three years later, American historian Jeffrey Herf backed this up in his book Reactionary Modernism, which showed that conservative thinkers of that time accepted modern techniques but didn't accept liberal democracy. Dupeux also pointed out that Conservative Revolutionaries opposed both forms of progressivism, which were liberalism and Marxism, and the cultural pessimism of reactionaries and conservatives. They tried to solve this by suggesting new types of reactionary governments that could fit into the modern world.Dupeux 1994 471–474
In his 1993 book Anatomy of the Conservative Revolution, German sociologist Stefan Breuer didn't accept Mohler's definition of "Conservative Revolution". He defined "conservatism" as wanting to keep the feudal structures of Germany, which were already dying during the Weimar period. Breuer saw Mohler's idea of the "Conservative Revolution" as a reflection of a new modern society aware of the problems of a simple modernity based only on science and technology. While he recognized the complexity of classifying that time intellectually, Breuer said he would have preferred the term "new nationalism" to describe a more engaging and complete version of German right-wing movements, as opposed to the "old nationalism" of the 19th century, which mainly focused on preserving traditional institutions and German influence globally.Merlio 2003 130
In 1996, British historian Roger Woods recognized that the idea was valid, but he emphasized that the movement was diverse and had trouble agreeing on a common plan, a political standstill he called the "conservative dilemma." Woods described the Conservative Revolution as "ideas that can't be simply explained as a political program, but are more like expressions of tension."Woods 1996 6 About the unclear connection with Nazism, which Mohler minimized in his 1949 thesis and 1970s analysts highlighted, Woods said that "even with some Conservative Revolutionary critiques of the Nazis, there remains a strong commitment to action, leadership, hierarchy, and a disregard for political programs. [...] Ongoing political issues lead to activism and a focus on hierarchy, which means there can be no strong opposition to the National Socialist rise to power."Woods 1996 134
Historian Ishay Landa has explained that the Conservative Revolution's idea of "socialism" is actually very capitalist. Landa indicates that Oswald Spengler's "Prussian Socialism" was strongly against labor strikes, trade unions, higher taxes on the wealthy, shorter workdays, and any government help for sickness, old age, accidents, or job loss. While rejecting any social welfare policies, Spengler praised private property, competition, imperialism, wealth gathering in the hands of the few elites, and capital growth. Landa describes Spengler's "Prussian Socialism" as working a lot for the least pay but being satisfied with it. Landa also describes Arthur Moeller van den Bruck as a "socialist supporter of capitalism" who valued free trade, active markets, the creativity of entrepreneurs, and the capitalist division of labor, aiming to replicate British and French imperialism. Landa points out that Moeller's criticism of socialism shares similarities with those of neoliberals like Friedrich von Hayek and states that "Moeller's writing is far from being against the capitalist spirit; it is full of it."
 Later influence 
The movement affected modern thinkers outside of German-speaking Europe. One notable figure is the Italian philosopher Julius Evola, who is linked to the Conservative Revolution.
The Nouvelle Droite, a French far-right group formed in the 1960s, aimed to adapt traditional and ethnically focused politics to post-WWII Europe and to separate itself from older far-right movements like fascism, mainly through a shared European nationalism. This group has been greatly shaped by the Conservative RevolutionFrançois 2017 and its German counterpart, the Neue Rechte.Pfahl-Traughber 1998 223–232
The ideas and framework of the Identitarian movement are largely influenced by the Nouvelle Droite, the Neue Rechte, and through them, the Conservative Revolution.


Indian Institute of Science: Indian Institute of Science (IISc) is a public university for scientific research. It is located in Bangalore, India. Jamshetji Tata gave active support to establish this institute. He is one of the earliest industrialists of India. IISc is well known as India's finest research university. 
History
In 1893, Jamshetji Tata had a chance meeting with Swami Vivekananda on a ship from Japan to Chicago. Then, Jamshetji Tata discussed his plan with Vivekananda to bring Iron and Steel industry to India. Five years later, Tata wrote a letter to Vivekananda about his desire to establish a research institution. He also asked Vivekananda for guidance in this matter. Vivekananda softly declined this proposal.
The government of Mysore donated (371 acres or 1.50 sq km) to build the institute. They also agreed to donate 50,000 rupees every year. The institute was established in 1909. It had two departments - Department of General and Applied Chemistry and Electro Technology. Morris Travers became the first director of IISc.
Campus
IISc campus is in Malleswaram, 4 km north of Bangalore City railway station. A number of other research institutes are nearby. These are Raman Research Institute, Central Power Research Institute and the Institute of Wood Science and Technology. There are regular bus services between them and IISc.
The campus is home to over 40 departments and centers of sciences. It has more than 3,000 students who are pursuing their undergraduate and postgraduate studies. The facilities on the campus include a library,gymnasium, dining halls and restaurants. There are dormitories for men and women and accommodation for staff members. A visitor's hostel was built in 1990. The campus is full of greenery. It has over 110 species of trees and rare and native plant species. The roads connecting the departments are named after species of trees. For example Arjun Marg (Marg means path in Hindi), Tala Marg and Silver Oak Marg.


2024 United States presidential election: July 2024
The 2024 United States presidential election was the 60th presidential election held every four years. The election was held on Tuesday, November 5, 2024, along with other state and federal elections. It was the first presidential election to use population information from the 2020 census. The Republican ticket of former President Donald Trump and Ohio U.S. senator JD Vance won the election. They defeated the Democratic ticket of incumbent Vice President Kamala Harris and Minnesota Governor Tim Walz.
President Joe Biden initially ran for reelection to a second term and became the Democratic Party's presumptive nominee, but ended his campaign on July 21, 2024 after a bad debate performance, concerns about his age and health, and declining popularity. He endorsed Vice President Kamala Harris for president. She picked Governor of Minnesota Tim Walz as her running mate. Had she won, she would have become the first female president in U.S. history. Harris is the second woman major party nominee to lose a U.S. presidential election after Hillary Clinton in 2016 (both lost to Trump). Harris was also the first nominee who did not participate in the primaries since Hubert Humphrey in 1968.
Donald Trump, who served as president from 2017 to 2021, ran for reelection to a nonconsecutive second term. He picked Ohio U.S. Senator JD Vance as his running mate. Trump is the first U.S. president to serve two nonconsecutive terms since Grover Cleveland in 1893. In 2023 and 2024, Trump was found liable and guilty in civil and criminal proceedings, becoming the first former president to be convicted of a crime. Trump narrowly survived an assassination attempt on July 13, 2024.
Some main campaign issues during the election cycle were abortion, border security and immigration, climate change, democracy, the economy, education, foreign policy, healthcare, and LGBT rights.
Trump won a decisive victory, winning 312 electoral college votes to Harris' 226. Additionally, Trump became the first Republican to win the national popular vote (majority of the vote share) since George W. Bush in 2004. Trump and Vance won the election in the early hours of November 6 as the next and 47th president and 50th vice president of the United States. Harris called Trump on November 6 to congratulate him. She delivered a concession speech later that day. Trump is the second president to be elected to a nonconsecutive second term, 132 years after Grover Cleveland won the 1892 election. Trump is also the oldest person ever elected president, at the age of 78. Harris is the most recent sitting vice president to run for the presidency and lose since Al Gore in 2000 and the most recent Democratic presidential nominee to lose the national popular vote since John Kerry in 2004.
 Background 
 Requirements 
Article Two of the United States Constitution states that for a person to serve as president, the person must be a natural-born citizen of the United States, be at least 35 years old, and have been a United States resident for at least 14 years. The Twenty-second Amendment prevents anyone from being elected president more than twice.
 Campaign topics 
 Abortion 
The Dobbs v. Jackson Women's Health Organization decision in June 2022 overturned the 1973 Roe v. Wade decision, allowing U.S. states to fully ban abortion for the first time in almost 50 years. This made abortion a campaign issue. The Republicans have been linked to Project 2025, which asks to completely ban abortion in the country.
 Crime 
Due to more mass shootings in the United States, President Biden has advocated a ban of assault weapons. This was most likely a major campaign topic in both parties.
 Inflation 
Republicans have blamed Democrats for the high inflation rates from 2021 to 2023.
 Democratic Party 
Joe Biden was the current president, elected for his first term in office in the 2020 election, and had said he planned to run for a second term in 2024. He was the oldest president, at age 78, and would've been 82 at the end of his first term and 86 at the end of a second term, if he was reelected.
During late 2021, as President Biden had low approval ratings in the polls, there was speculation that he would not run for reelection. If this happened, Vice President Kamala Harris and Secretary of Transportation Pete Buttigieg would be considered likely candidates for the Democratic presidential nomination, having both run for president in 2020. However, Biden said he had every intention of running for reelection.
In March 2023, author and 2020 presidential candidate Marianne Williamson announced her presidential campaign, challenging Biden. In April 2023, environmental lawyer Robert F. Kennedy Jr. announced his challenge to Biden, becoming the second Democratic challenger to Biden. On April 25, 2023, President Joe Biden announced he was running for re-election with Vice President Kamala Harris as his running mate.
In October 2023, Kennedy Jr. announced he would be withdrawing from the Democratic primary to run an Independent campaign for president. A few weeks later, U.S. Representative from Minnesota Dean Phillips announced his candidacy on October 26, 2023. Spiritual author Marianne Williamson ended her campaign on February 7, 2024. She would then re-enter the race a few weeks later after winning 3% of the vote in the Michigan primary. Williamson would end her campaign again on June 11, 2024.
During the first presidential debate in late June, many people saw that Biden did not do well with his polling numbers showing him losing to Trump by a bigger margin than before. Many Democrats wanted him to end his campaign with Marianne Williamson re-entering the race a third time. On July 21, 2024, Biden announced that he was ending his presidential campaign, allowing the Democratic Party to choose a new candidate. He endorsed Vice President Kamala Harris for the nomination. The next day, most of the delegates said they would vote for Harris, enough for her to become the presumptive nominee.
On August 6, 2024, Harris picked Governor of Minnesota Tim Walz as her running mate. Pennsylvania Governor Josh Shapiro, Kentucky Governor Andy Beshear, Illinois Governor J. B. Pritzker, Arizona U.S. Senator Mark Kelly and Secretary of Transportation Pete Buttigieg were seriously considered as running mate options and were vetted by the Harris campaign as well.
The Democratic National Convention was held in Chicago, Illinois at the United Center between August 19 to 22, 2024.
 Democratic nominee 
 Democratic Disc.svg
  Democratic Party (United States)
  2024 Democratic Party ticket
  Kamala Harris
  Tim Walz
  Kamala Harris Vice Presidential Portrait (cropped).jpg
  Tim Walz by Gage Skidmore (cropped).jpg
  49thVice President of the United States(2021–2025)
  41stGovernor of Minnesota(2019–present)
  Kamala Harris 2024 presidential campaign
  Harris Walz 2024 presidential campaign logo.svg
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 Withdrew after the primaries 
Withdrew during the primaries
 Republican Party 
Donald Trump was defeated by Joe Biden in 2020 and was impeached by the House of Representatives. He was found not guilty in his second impeachment in 2021 and was able to run again in the 2024 election. He is the second president, after Grover Cleveland, to serve two non-consecutive terms, making him both the 45th and 47th president of the United States.
House Democrats considered using the Fourteenth Amendment to prevent Trump from being eligible to run again. Trump is the first president since Richard Nixon to win his party's nomination three times.
The last president to run after leaving office was Theodore Roosevelt, who came in second in the 1912 election as the candidate of the Progressive Party, although Herbert Hoover did seek the Republican nomination at national conventions after leaving office in 1933. On November 11, 2022, former Montana Secretary of State Corey Stapleton became the first Republican major candidate.
On November 15, 2022, he officially announced his candidacy to a non-consecutive term. On February 14, 2023, former Ambassador to the United Nations Nikki Haley announced her candidacy. A week later, businessman Vivek Ramaswamy announced his campaign on February 21. On March 2, 2023, Michigan businessman and writer Perry Johnson announced his campaign after running ads during the Super Bowl in Iowa.
In April 2023, former Governor of Arkansas Asa Hutchinson announced his campaign and so did Texas businessman and pastor Ryan Binkley, while South Carolina U.S. Senator Tim Scott announced an exploratory committee for a possible presidential campaign. Scott would file to run on May 19, 2023. On April 20, conservative radio host and former 2021 California gubernatorial candidate Larry Elder announced his candidacy. On May 24, Governor of Florida Ron DeSantis announced his candidacy. Nearly two weeks later on June 5, former Vice President Mike Pence filed paperwork to run for president. The following day, former New Jersey Governor Chris Christie announced his campaign at a town hall event in New Hampshire. On June 7, Governor of North Dakota Doug Burgum announced his campaign. A week later on June 14, Miami Mayor Francis X. Suarez filed to run for president. On June 22, former Texas U.S. Representative Will Hurd announced his campaign.
Following the first debate, Suarez withdrew from the election on August 29, after saying non-debate qualified candidates should withdraw from the race. In early October 2023, Hurd and Stapleton withdrew from their candidacies with Hurd supporting Haley. By the end of the month, Johnson and Elder suspended their campaigns and endorsed Trump, whereas Pence dropped out without supporting anyone. On November 12, Senator Tim Scott ended his campaign after having low polling numbers. On December 4, Burgum ended his campaign after low polling numbers and failing to qualify for the last two debates.
On January 10, 2024, a week before the Iowa caucus, former Governor Chris Christie ended his campaign, after Trump critics urged him to drop out to help Nikki Haley in the New Hampshire primary. Following Trump's win in the Iowa caucus on January 15, 2024, Vivek Ramaswamy ended his campaign and endorsed Trump, whereas former Governor Asa Hutchinson ended his campaign the following day and endorsed Healey. On January 21, Governor Ron DeSantis ended his campaign and endorsed Trump. On February 27, pastor Ryan Binkley ended his campaign and endorsed Trump.
On July 13, 2024, just two days before the Republican National Convention, during a campaign rally in Butler, Pennsylvania, Trump was shot in the right ear in an attempted assassination. Two days after the shooting, Trump picked Ohio U.S. Senator JD Vance to be his running mate. North Dakota Governor Doug Burgum, South Carolina U.S. Senator Tim Scott and Florida U.S. Senator Marco Rubio were also seriously considered and vetted by the Trump campaign to be his running mate.
The Republican National Convention was held in Milwaukee, Wisconsin at the Fiserv Forum between July 15 and 18, 2024. Other cities considered to host the convention included Salt Lake City, Kansas City, Nashville and Pittsburgh.
Similar to other Presidential campaigns, Trump had the issue of age —he turned 78 in June 2024. He will be 82 when his term ends.
Republican nominee
 Republican Disc.svg
  Republican Party (United States)
  2024 Republican Party ticket
  Donald Trump
  JD Vance
  Official Presidential Portrait of President Donald J. Trump (2025).jpg
  JD Vance Inaugural Portrait (cropped).png
  45thPresident of the United States(2017–2021)
  U.S. Senatorfrom Ohio(2023–2025)
  Donald Trump 2024 presidential campaign
  TrumpVance2024.png
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 Withdrew during the primaries 
The candidate in this section have suspended their campaigns, or have otherwise ceased campaigning and ended their bids for the nomination during the primary season.
 Withdrew before the primaries 
The candidates in this section have suspended their campaigns, or have otherwise ceased campaigning and ended their bids for the nomination before any primary contests were held.
Other notable individuals who were not considered major candidates and who withdrew from the race before the beginning of the primary season include:
 Steve Laffey, mayor of Cranston, Rhode Island (2003–2007)
 Major Independents and third parties 
With majority ballot access
 Libertarian Party 
Chase Oliver was chosen by the Libertarian Party as its presidential nominee on May 26, 2024, at the 2024 Libertarian National Convention. May 2024, the party has ballot access in at least 37 states with a total of 380 electoral votes.
 Libertarian Disc.svg
  Libertarian Party (United States)
 black
  2024 Libertarian Party ticket
  Chase Oliver
  Mike ter Maat
  Chase Oliver by Gage Skidmore 2.jpg
  Mike Ter Maat on the "LibertyDad" Podcast.jpg
  Sales account executivefrom Georgia
  Economistfrom Virginia
  Chase Oliver 2024 presidential campaign
  Chase Oliver 2024 Campaign Logo.svg
  Gold
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Green Party
Jill Stein announced on May 26, 2024, that her campaign had accrued enough delegates to win the Green Party nomination. Stein was also the party's candidate in 2012 and 2016. The 2024 Green National Convention took place on August 15–18, 2024. June 2024, Stein has ballot access both on Green Party and Independent ballot lines in at least 22 states with a total of 273 electoral votes.June 2024
 Green Disc.svg
  Green Party of the United States
  2024 Green Party ticket
  Jill Stein
  Butch Ware
  Jill Stein by Gage Skidmore 3.jpg
  Butch Ware in 2024.jpg
  Physicianfrom Massachusetts
  Academicfrom California
  Jill_Stein_2024.png
  Jill Stein 2024 presidential campaign
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Party for Socialism and Liberation
Community organizer Claudia De la Cruz announced her campaign for president on September 7, 2023 with Karina Garcia as her running mate under the Party for Socialism and Liberation ticket. In 2024, Democrats have been working to keep PSL candidate Claudia De la Cruz along with some other third-party candidates like Cornel West off of ballots, while Republicans have been working to get them onto ballots.
 Party for Socialism and Liberation in a circle.png
  Party for Socialism and Liberation
  2024 Party for Socialism and Liberation ticket
  Claudia De la Cruz
  Karina Garcia
  Claudia De la Cruz (cropped).png
  Karina Garcia.png
  Activistfrom New York
  Activistfrom California
  ClaudiaKarina-Logo.svg
  Claudia De la Cruz 2024 presidential campaign
  ClaudiaKarina-Logo.svg
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Constitution Party
On March 29, 2024, anti-abortion activist Randall Terry declared his candidacy in the presidential election. He was nominated by the Constitution Party for president on April 27, 2024. He said he would not accept the nomination if Stephen Broden was not nominated for vice president.
  Constitution Party (United States)
  2024 Constitution Party ticket
  Randall Terry
  Stephen Broden
  Randall Terry by Gage Skidmore.jpg
  Stephen Broden (16405782316) (cropped).jpg
  Activistfrom Tennessee
  Pastorfrom Texas
  Terry Broden 2024 Campaign Logo.png
  Randall Terry 2024 presidential campaign
  Terry Broden 2024 Campaign Logo.png
  200px
- CCCCFF
American Solidarity Party
On June 2, 2023, the American Solidarity Party announced that former radio host and museum director Peter Sonski had been selected as the party's presidential nominee. He was selected after winning the party's online primary. Teacher and non-profit executive Lauren Onak from Massachusetts was selected as his running mate after being the only person to run for the vice presidential nomination.
 Parti de la solidarité américaine.png
  American Solidarity Party
  2024 American Solidarity Party ticket
  Peter Sonski
  Lauren Onak
  Museum directorfrom Connecticut
  Non-profit executivefrom Massachusetts
  American Solidarity Party 2024 Campaign Logo.png
  Peter Sonski 2024 presidential campaign
  American Solidarity Party 2024 Campaign Logo.png
  200px
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Notable Independents
Cornel West
Cornel West is a socialist activist and intellectual who announced a campaign as an independent after initially announcing a run as a People's Party and later a Green Party candidate. His running mate is Melina Abdullah, an academic and civic leader from California. West_POTUS_24.png
  Independent politician
  2024 independent ticket
  Cornel West
  Melina Abdullah
  Cornel_West_by_Gage_Skidmore.jpg
  Melina Abdullah (27700459240) (cropped).jpg
  Academic and activistfrom California
  Academic and civic leaderfrom California
  Cornel West 2024 presidential campaign
  West Abdullah black logo.png
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 Shiva Ayyadurai 
Shiva Ayyadurai is an activist, inventor and businessman whose career focuses on biological systems and computer science. He announced his Independent campaign for president on April 19, 2023. His running mate is Crystal Ellis, who is an entrepreneur and activist from Nebraska.
 Shiva2024 1 (cropped).png
  Independent politician
  2024 independent ticket
  Shiva Ayyadurai
  Crystal Ellis
  Shiva Ayyadurai Portrait.jpg
  Crystal Ellis cropped.jpg
  Scientist and Activistfrom Massachusetts
  Entrepreneur and Activistfrom Nebraska
  Shiva Ayyadurai 2024 presidential campaign
  S4P-Logo.png
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- A9A9A9
 Withdrawn candidates 
The following notable individual(s) announced and then suspended their campaigns before the election:
 Robert F. Kennedy Jr. (campaign), environmental lawyer (endorsed Trump)
 Kanye West, rapper and 2020 presidential candidate
 Debates 
Two presidential debates and one vice presidential debate were scheduled.
Opinion polling
 LOESS graph of the opinion polling between Harris and Trump taken during 2024. The dashed line is when Harris became the presumptive Democratic nominee.
 LOESS graph of the opinion polling between Harris and Trump since the 2020 U.S. presidential election. The dashed lines are when both candidates became the presumptive nominees for their respective parties.
 LOESS graph of the opinion polling between Harris and Trump since the 2020 U.S. presidential election with Independent candidates Robert F. Kennedy Jr. and Cornel West and Green Party candidate Jill Stein. The dashed lines are when both major candidates became the presumptive nominees for their respective parties.
 Results 
 Electoral results 
November 2024
 Results by state 
November 2024


Solar System: The Solar System is a group of space objects that are held together by gravity, with the Sun in the center. The Sun is a huge ball of hot glowing gas that gives off light and heat. Everything else in the Solar System moves around the Sun. The Solar System formed about 4.6 billion years ago when a giant cloud of gas and dust collapsed and started to spin. Most of the material went into forming the Sun, and the rest became planets and other objects. There are eight main planets, including Earth, and many moons that orbit them. There are also dwarf planets like Pluto, as well as asteroids, comets, meteoroids, and tiny particles called interplanetary dust. Our Solar System is part of a galaxy called the Milky Way. It lies in a part of the galaxy called the Orion Arm, about 27,000 light-years from the center of the Milky Way. 
There are eight planets in our Solar System. Starting from the closest to the Sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Scientists often group them into two main types. Terrestrial planets (Mercury, Venus, Earth, and Mars) are small and made mostly of rock and metal. Giant planets include gas giants (Jupiter and Saturn), made mostly of hydrogen and helium, and ice giants (Uranus and Neptune), which have more icy materials like water, methane, and ammonia. Each planet moves around the Sun in an oval-shaped path called an ellipse. These paths are all mostly in the same flat area of space, called the ecliptic plane. Many planets have moons, which are natural objects that orbit them. Some planets, like Saturn and Jupiter, also have rings made of ice and dust particles that circle around them.
Far beyond the planet Neptune is a region called the Kuiper Belt. This area is filled with icy objects, including small worlds called dwarf planets, like Pluto, Haumea, and Makemake. These objects are made mostly of rock and ice and orbit the Sun just like the planets, but they are much smaller. Even farther out is a zone called the scattered disk, and beyond that is a mysterious, faraway area called the Oort Cloud. Scientists think the Oort Cloud is a huge, invisible shell of icy objects surrounding the Solar System. It may be where long-period comets come from, those that take hundreds or thousands of years to travel around the Sun. These distant regions are at the edge of the Sun’s power. The Sun’s gravity and solar wind stretch out to form a giant bubble called the heliosphere. This marks the boundary of the Sun’s influence, even farther than where the planets orbit.
The Solar System has more than just planets and moons. It also has thousands of space rocks called asteroids. Most of these are found in a big area between the planets Mars and Jupiter. This area is called the asteroid belt. Some asteroids, called Trojan asteroids, share their paths around the Sun with planets. There are also comets. Comets are made mostly of ice and dust. They move in long, stretched-out paths around the Sun. When a comet gets close to the Sun, the heat makes it grow a glowing tail that points away from the Sun. Smaller pieces of rock and metal, called meteoroids, also float around in space. If one of these enters Earth’s atmosphere, it burns up and creates a bright streak in the sky. That’s what we call a meteor or a shooting star. If part of it survives the trip and lands on the ground, it is called a meteorite.
The Sun is by far the biggest and most powerful object in the Solar System. It makes up more than 99.8% of all the mass, which means almost all the weight in the Solar System comes from the Sun. The Sun is a type of star that produces energy in its center through a process called nuclear fusion. This means it turns a gas called hydrogen into another gas called helium. When it does this, it releases a huge amount of energy. This energy spreads out in all directions as light, heat, and other types of radiation. The Sun also sends out a flow of tiny, charged particles called the solar wind. This wind can hit the magnetic fields and atmospheres of planets like Earth. When this happens, it can cause things like the auroras, the colorful lights in the sky near the North and South Poles. The solar wind also affects space weather, which can sometimes interfere with satellites and power systems on Earth.
Scientists believe the Solar System formed from a big spinning cloud of gas and dust. This idea is called the nebular hypothesis. Over time, the cloud began to collapse and spin faster, forming a flat disk. Most of the material gathered in the center to form the Sun, while the rest started forming planets. Closer to the Sun, it was very hot, so only rocky materials could stick together. That’s why the inner planets like Mercury, Venus, Earth, and Mars are made of rock. Farther out, it was much colder, so gases and ices could join together to form the giant planets like Jupiter and Saturn. Over billions of years, the planets moved around, crashed into other objects, and were affected by gravity. These changes helped shape the Solar System into the way we see it today.
People have been studying the Solar System for thousands of years. Ancient civilizations watched the sky and noticed how the planets and stars moved. They used this knowledge to make calendars and guide their lives. A big change came in the 1500s, when a man named Nicolaus Copernicus said that the Sun, not the Earth, was at the center of the Solar System. This idea is called the heliocentric model, and it replaced the older belief that everything moved around the Earth. It was a major turning point in how people understood space. Later, in the 1600s, Isaac Newton came up with the laws of motion and gravity. These laws helped explain how the planets move and why they stay in orbit around the Sun. In more recent times, the 1900s and 2000s, we have sent robotic spacecraft to explore the Solar System. Missions like Voyager, Cassini, Juno, and the Mars rovers have taught us a lot about the planets, moons, and even the chance of finding life somewhere else in space.
 Formation and Evolution of the Solar System 
Formation of the Sun and Protoplanetary Disk
The formation and evolution of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. The solar nebula was the cloud of gas and dust that eventually formed the Sun and all the planets. This cloud did not just appear out of nowhere. It came from the interstellar medium, which is the thin, spread-out stuff that fills the space between stars. The part of space that formed our solar system was probably in a giant molecular cloud. These are cold, thick areas in space where new stars are often born. That’s why scientists sometimes call them stellar nurseries. These clouds were made mostly of hydrogen and helium, the two lightest elements. But they also had tiny amounts of heavier elements like carbon, oxygen, silicon, and iron. These heavier elements were made by older stars that had exploded in huge blasts called supernovas. When these stars exploded, they sent these elements out into space, mixing them into the cloud. Because of these ingredients, our part of the cloud had everything needed to form rocky planets like Earth and even the building blocks of life.
The formation of our Solar System began with a triggering event, something that caused part of a giant cloud of gas and dust to start collapsing. Scientists are not completely sure what started it, but there are a couple of good guesses. One idea is that a nearby supernova, a huge explosion at the end of a star’s life, sent out a powerful shockwave. This shockwave may have hit the cloud, pushing and squeezing the gas and dust until it became dense enough for gravity to take over. Another possibility is that small instabilities inside the cloud caused it to start collapsing on its own. Once gravity became stronger than the pressure trying to push the gas outward, the center of the cloud started to collapse inward. As it collapsed, it began to spin and flatten, forming a thicker, spinning area called the protosolar nebula. This was the early stage of what would eventually become the Sun and planets.
As the center of the giant cloud of gas and dust collapsed, it started to spin faster. This happened because of a rule in physics called conservation of angular momentum, kind of like how a figure skater spins faster when they pull their arms in. As the spinning increased, the cloud also flattened into a disk. In the middle of this spinning disk, more and more gas and dust gathered, making the center hotter and denser. As this cloud got smaller, most of the material started gathering in the center, forming a growing ball of gas called a protostar. This was the very early stage of what would become the Sun. As more gas and dust fell into the center, the protostar got hotter and denser. The particles inside began to crash into each other more often, causing the pressure to rise. When the core reached a temperature of about 10 million Kelvin, a powerful reaction called nuclear fusion started. During fusion, hydrogen atoms joined together to form helium, and this released a huge amount of energy. At this moment, the Sun officially came to life as a main-sequence star. Once fusion began, the Sun started giving off strong light, heat, and solar wind, a stream of tiny, charged particles. This wind helped blow away the extra gas and dust in the inner Solar System. This clearing-out process is called photoevaporation. It helped stop more material from falling into the Sun and made room for the planets to start forming. Even though the Sun was still young, it now had strong gravity and energy that controlled everything around it. The Sun had become the center of the Solar System.
Surrounding the young Sun was a large, spinning disk of gas and dust called the protoplanetary disk. This material was left over from the cloud that formed the Sun. The disk was flat like a pancake and rotated around the Sun. This disk was not the same all over, it had different temperatures in different places. The part closest to the Sun was very hot because of the Sun’s strong light and heat. In this hot area, only tough materials like metals and rocks could stay solid. These materials came together to form the rocky planets like Mercury, Venus, Earth, and Mars. Farther away from the Sun, the disk was much cooler. In this colder area, things like water, ammonia, and methane could freeze into ice. These icy and gassy materials helped form the gas and ice giants, planets like Jupiter, Saturn, Uranus, and Neptune. So, the different temperatures in the disk helped decide what kind of planets would form in different parts of the Solar System. This model, known as the nebular hypothesis, was developed in the 18th (1700s) century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. It has been adjusted by scientific disciplines such as astronomy, physics, geology, and planetary science. As our knowledge of space has grown, the models have been changed to account for the new observations.
One important part of the protoplanetary disk was something called the snow line (also known as the ice line). This was an invisible boundary in the disk that marked the point where it was cold enough for water and other gases to freeze into ice. Inside the snow line, closer to the Sun, it was too hot, so only rock and metal could stick together and form solid objects. That’s why the inner planets, like Earth and Mars, are made mostly of rock. Beyond the snow line, it was much cooler, and there were lots of ices in addition to rock. These ices made it easier for large planet cores to grow quickly. Once these big cores formed, they had strong enough gravity to pull in lots of gas from the disk around them. This is how the giant planets like Jupiter and Saturn were able to form.
Formation of the Planets
The process of forming planets began inside the spinning disk of gas and dust around the young Sun. It all started with tiny dust grains made of things like rock, metal, and ice. These grains were spread all throughout the disk. At first, the dust grains were tiny. But as they floated in the gas, they bumped into each other and started to stick together. This happened because of electrostatic forces, the same kind of static electricity that makes a person's hair stand up. Over time, the grains grew bigger and turned into pebbles, then clumps, and finally into objects that were about a kilometer wide. These larger bodies are called planetesimals, and they were the first real building blocks of planets. As the planetesimals (small space rocks) kept growing, something important started to happen, gravity became a big deal. The larger planetesimals had stronger gravity, which let them pull in more nearby dust and rocks. This made them grow even faster. This fast-growing phase is called runaway accretion. During runaway accretion, the biggest planetesimals kept getting bigger and bigger, leaving the smaller ones behind. These big ones started to take over certain parts of the disk, becoming the main objects in their areas. After most of the smaller pieces were gone, the growth slowed down. This slower stage is called oligarchic growth. In this phase, several large bodies, called planetary embryos, formed. These were about the size of the Moon or even Mars. Each embryo controlled a small area of the disk. Over millions of years, the large space rocks called planetary embryos began to crash into each other, join together, or pull on each other with gravity. These actions helped shape the final layout of the planets in the Solar System. In the inner part of the Solar System, where there were mostly rocky materials, these giant collisions eventually formed the rocky planets like Mercury, Venus, Earth, and Mars. In the outer part, beyond the snow line where it was much colder, some embryos grew so big that their gravity could pull in thick layers of gas, mainly hydrogen and helium. These became the huge gas and ice giants like Jupiter, Saturn, Uranus, and Neptune.
One of the most important events in the story of how planets formed is the creation of Earth’s Moon. Scientists believe the Moon was formed by a giant impact. This idea is called the giant impact hypothesis. According to this theory, about 4.5 billion years ago, a space object about the size of Mars, which we call Theia, crashed into the young Earth. The crash was so powerful that it melted parts of both worlds and sent a huge amount of debris into space around Earth. This debris, made mostly of rock from Earth’s outer layers, slowly came together because of gravity. Over time, the pieces joined to form the Moon. Scientists believe this theory is true because the Moon is made of materials very similar to Earth’s outer layers, especially the mantle. Also, the Moon does not have many gases or a large iron core, which supports the idea that it formed from Earth’s surface material, not from a separate object that was captured.
As young planets were forming, something important called planetary differentiation began to happen. This is the process where the inside of a planet becomes layered, with heavier materials sinking and lighter ones rising. As the planets grew bigger, they got hotter inside. This heat came from radioactive decay, big impacts, and the pressure of gravity squeezing the planet. The heat was so strong that parts of the inside of the planet began to melt. When a planet is melted, the materials inside can separate by weight. Heavy materials like iron and nickel sank to the center to form the core. Lighter materials, such as silicate rocks, floated upward to form the mantle and crust. Differentiation helped planets develop many important features. One major result was the formation of metallic cores inside planets like Earth. These cores moved and flowed, creating magnetic fields that protect the planet from harmful space radiation. At the same time, volcanoes released gases from inside the planet in a process called outgassing. These gases, along with materials delivered by space rocks, helped form the planet’s atmosphere. On Earth, this made it possible for life to eventually develop. The leftover heat from the planet’s formation, along with moving materials inside the planet, caused ongoing geological activity. This includes things like volcanoes, earthquakes, and tectonic plate movement. These processes helped shape the planet’s surface and kept the planet active.
The gas giants, like Jupiter and Saturn, formed in a different way than the smaller rocky planets like Earth. This is because they were born in the colder, outer parts of the Solar System, beyond a boundary called the snow line, where ices could form and last. Scientists have two main ideas about how these big planets formed. The most popular one is called the core accretion model. According to this idea, the process began with icy space rocks, called planetesimals, slowly sticking together to form a large solid core. This core had to be about 10 times the size of Earth to be strong enough. Once the core got that big, its gravity became powerful enough to pull in large amounts of gas, especially hydrogen and helium, from the surrounding disk. This made the planets grow very quickly and gain their thick, gassy outer layers. But this had to happen fast, within just a few million years, before all the gas in the protoplanetary disk disappeared. If the gas was gone, the planet could not grow into a gas giant. Another idea about how gas giants like Jupiter and Saturn formed is called the disk instability model. Instead of starting with a solid core, this theory suggests that parts of the gas disk around the Sun became unstable and collapsed under their own gravity. These collapsing clumps of gas could have turned directly into gas giants, without needing a rocky center first. This model could explain how gas giants formed very quickly, which is something the core accretion model struggles with. However, scientists do not have much direct evidence that this happened in our Solar System, so the core accretion model is still the more popular idea.
The ice giants, Uranus and Neptune, formed differently from both the rocky planets and the gas giants. They were born farther from the Sun, in a place where there was less material to build planets. According to the core accretion model, these planets started out by forming solid cores, just like Jupiter and Saturn. But because there was not as much gas around, or because the gas did not last very long, they could not pull in as much hydrogen and helium. So, they ended up with only thin layers of gas. Instead of having thick, gassy atmospheres, ice giants are made mostly of volatiles, substances like water, ammonia, and methane. Even though we call them “ice” giants, much of this material is actually in a hot, thick, fluid form deep inside the planets because of the high pressure. This is why Uranus and Neptune are smaller than Jupiter and Saturn and have a different makeup. At the same time as the planets were forming, the outer edges of the Solar System were creating dwarf planets and other icy objects. Far beyond Neptune, there’s a region called the Kuiper Belt. In this area, leftover pieces from the early Solar System came together to form objects like Pluto, Eris, and Haumea. These icy bodies are like frozen time capsules. They have not changed much since they first formed, so they give scientists clues about what the outer Solar System was like long ago. Their icy make-up and stable orbits tell us about the cold, quiet conditions far from the Sun. Some of these objects might not have started out in the Kuiper Belt. They may have formed closer to the Sun and were later pushed outward by the strong gravity of the moving gas giants, like Jupiter. This idea supports theories like the Nice model, which explains how the planets and other objects ended up where they are today.
Evolution of the Solar System
One of the most important steps in the Solar System's history was the clearing of the protoplanetary disk. This was the spinning cloud of gas and dust around the young Sun where planets were forming. As the Sun got older and became a full main-sequence star, it started sending out strong solar winds, streams of tiny, charged particles. It also gave off intense ultraviolet radiation. Together, these forces began to blow away the leftover gas and dust in the disk. This process is called photoevaporation. Photoevaporation was especially strong in the inner part of the Solar System, where the Sun's heat and light were most powerful. Once the gas was gone, planets could not grow much more, especially gas giants, because the materials they needed had disappeared. Scientists believe this clearing happened within about 10 million years after the Solar System began. We know this by looking at other young stars and their disks in space today. The clearing of the disk marked the end of major planet formation and shaped the Solar System as we know it.
After the planets finished forming and started to settle into their orbits, the Solar System went through a chaotic time called the Late Heavy Bombardment (LHB). This happened about 4.1 to 3.8 billion years ago and was a period when the inner planets, like Earth, the Moon, Mars, and Mercury, were hit by tons of asteroids and comets. Scientists know this happened because of rock samples from the Moon that were brought back by the Apollo missions. Scientists studied the craters on the Moon and used special techniques to figure out how old the rocks were. They found that many of the Moon’s biggest craters, like the Imbrium and Orientale basins, were all made around the same time. This shows that there was a sudden increase in space impacts, not just a slow decline over time. The same thing probably happened on Earth and other nearby planets. Meteorites found on Earth and information from Mars also support the idea that this was a Solar System-wide event with a huge number of collisions happening in a short period.
Scientists are still trying to figure out exactly what caused the Late Heavy Bombardment (LHB), but one popular idea is called the Nice model (named after a city in France). This model suggests that the giant planets, like Jupiter and Saturn, did not always stay in the same orbits. They might have moved. At some point in the early Solar System, Jupiter and Saturn may have crossed a special point in their orbits called a resonance. This happens when their orbits line up in a way that their gravitational pulls reinforce each other. In this case, it created a powerful gravitational effect that caused destabilized the orbits of many icy bodies in the Kuiper Belt and rocky objects in the asteroid belt. These objects were either flung out of the Solar System or sent crashing inward toward the inner planets, like Earth, Mars, and Venus. This sudden movement of so many objects led to the Late Heavy Bombardment, when the inner planets were hit by lots of asteroids and comets. These impacts helped shape the surfaces of the planets and may have even brought water and organic materials to Earth, ingredients that later made life possible.
One idea in planetary science is the Grand Tack hypothesis. This theory tries to explain some strange things about our Solar System by suggesting that Jupiter did not always stay where it is now. Instead, it says that Jupiter once moved inward, getting much closer to the Sun, about 1.5 times the distance from Earth to the Sun, before turning around and moving back outward to where it is today. This big change in direction, or "tack" (like a sailboat changing course), may have happened because of Saturn. After Jupiter formed, Saturn also started forming, and the gravity between the two may have caused Jupiter to change direction. As Jupiter moved inward, it would have pushed away or scattered a lot of dust, rocks, and planetesimals. This would have cleared out space in the Solar System and changed how the rocky planets, like Earth and Mars, formed. When Jupiter moved back outward, it may have pulled in a new mix of material, adding both rocky and icy objects into the asteroid belt. This helps explain why the asteroid belt today has a mix of different types of asteroids, some rocky, some icy.
One big area scientists study is how the orbits of planets, moons, asteroids, and comets change over time. These changes happen slowly and are often caused by gravity pulling on objects in special ways. One important idea is called a resonance. This happens when two objects go around the Sun in a regular pattern, like one going around twice for every three times the other one goes around. These simple ratios (like 2:1 or 3:2) can keep orbits stable or sometimes make them unstable. Resonances help explain why the asteroid belt looks the way it does, why certain moons are in just the right spots, and why icy objects beyond Neptune tend to cluster in certain areas. Another idea is called secular variation, which means slow, long-term changes in things like a planet’s orbit shape, tilt, or direction. These changes happen because planets gently pull on each other over millions of years. For example, Earth’s orbit and tilt slowly shift because of the gravity from Jupiter and Saturn. These changes affect Earth’s climate over a long time, in something called Milankovitch cycles. Sometimes, gravity can even throw objects off course or capture them. This is called gravitational scattering. For example, Neptune’s moon Triton orbits backward, which suggests it did not form around Neptune but was a Kuiper Belt object that got caught by Neptune’s gravity. Mars’s tiny moons, Phobos and Deimos, may also be captured asteroids because of their strange shapes and materials.
Another important force that helps shape the Solar System is tidal interaction, especially between planets and their moons. Tidal forces happen because of gravity. Planets pull on their moons, and moons pull back on their planets. This tugging creates bulges, which causes energy to be lost and leads to slow changes in orbits and rotation. One famous example is the Earth and Moon. Because of tidal forces, the Moon always shows the same side to Earth. This is called being tidally locked. Also, Earth’s rotation is slowly slowing down, and the Moon is very slowly moving farther away from us. Tidal forces can also create heat inside moons, especially those that orbit big planets like Jupiter and Saturn. For example, Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) are squeezed and stretched as they move around their planets. This squeezing, called tidal flexing, creates heat inside them. That heat might keep liquid oceans under their icy surfaces. These hidden oceans could have geysers or even cryovolcanoes (volcanoes that erupt ice instead of lava). Because of this, Europa and Enceladus are interesting places to look for life beyond Earth.
The Present-day Conditions of the Solar System
At the very center of the Solar System is the Sun, which is a middle-aged star called a G-type main-sequence star. The Sun is very massive, it holds more than 99.8% of all the mass in the Solar System. The Sun gives off light and heat, which make life on Earth possible. It also creates the gravity that keeps all the planets, moons, asteroids, and comets moving in their orbits. Even though the Sun looks calm in the sky, it is actually very active. It gives off radiation and sends out a stream of charged particles called the solar wind. This wind stretches far out into space and helps create the edge of a giant bubble called the heliosphere, which surrounds the entire Solar System.
Surrounding the Sun are the eight major planets, which are split into two main groups. The first group is the terrestrial planets, Mercury, Venus, Earth, and Mars. These are small, rocky planets made mostly of rock and metal. The second group includes the gas and ice giants, Jupiter, Saturn, Uranus, and Neptune. These planets are much bigger and made mostly of gases like hydrogen and helium, and ices such as water, ammonia, and methane. All the planets move in oval-shaped orbits (called elliptical orbits) around the Sun, and they mostly stay in the same flat area called the ecliptic plane. Most of them spin in the same direction as the Sun, but there are a couple of exceptions. Venus spins backward, and Uranus spins on its side. Besides the planets, the Solar System also has lots of smaller objects. Between Mars and Jupiter is the asteroid belt, which contains millions of space rocks. Some as small as dust, and others as big as the dwarf planet Ceres. Even farther out is the Kuiper Belt, which is full of icy objects like Pluto, Haumea, and Makemake. These are called trans-Neptunian objects (TNOs), and they are leftovers from the Solar System's early days. They never became planets because the gravity from the big planets, like Jupiter, kept pulling things around and disturbing them. Way beyond that, scientists think there is something called the Oort Cloud. It is a giant, round shell of icy objects that surrounds the Solar System. Scientists have not seen it directly, but they think it is there because it is likely the home of long-period comets. The ones that take hundreds or thousands of years to orbit the Sun. The Oort Cloud is believed to be the very edge of the Sun’s gravitational reach.
The Solar System is always changing. It is not just made of planets and moons, there are lots of smaller objects moving around too, like comets, meteoroids, and centaurs. Centaurs are unusual because they have features of both asteroids and comets. Sometimes, comets from faraway places like the Kuiper Belt or the Oort Cloud travel into the inner part of the Solar System. As they get closer to the Sun, the heat causes their ice to melt, creating bright tails of gas and dust. These tails can be really beautiful and are often visible from Earth. Meteoroids are small rocks that sometimes enter Earth’s atmosphere. When they burn up in the sky, we see them as meteors or "shooting stars." If a bigger piece makes it all the way to the ground, it is called a meteorite. While big impacts are rare, scientists still keep an eye on near-Earth objects (NEOs) just in case. Centaurs are icy objects with unstable orbits between Jupiter and Neptune. They might one day become short-period comets that visit the inner Solar System more often. In recent years, astronomers even discovered objects from outside our Solar System, like ‘Oumuamua and Comet 2I/Borisov. These interstellar visitors came from far beyond the Sun’s reach, giving us clues about how other star systems might form.
There are over 800 known moons in our Solar System, and they come in all shapes and sizes. Some moons are fiery and active, like Io, which has volcanoes constantly erupting. Others, like Europa and Enceladus, are covered in ice but may have liquid oceans hidden underneath. These icy moons are interesting because they might even have the right conditions for life. Some planets, like Saturn and Neptune, have lots of moons, creating huge moon systems that scientists are still exploring and learning about. Besides natural moons, the Solar System also has many spacecraft and satellites that humans have sent into space to learn more about our Solar System. Some of these orbit Earth, while others go much farther. For example, Voyager 1 has traveled so far that it has entered interstellar space, beyond the edge of the Solar System. Other missions like Juno (orbiting Jupiter), Perseverance (exploring Mars), the James Webb Space Telescope, and New Horizons (which flew past Pluto) are helping us study planets, moons, and stars in detail.
Over billions of years, the planets in our Solar System have settled into stable orbits. This means that even though their paths can slowly change, they mostly stay the same over time. These changes happen very slowly and are caused by gravity pulling on the planets from other planets and the Sun. The way the planets are arranged now is called the current epoch, and it is expected to stay stable for billions more years. The orbits might change a little in shape or tilt, but not in a way that causes big problems. This stability is really important because it means we can predict how planets move far into the future. It also helps keep Earth safe and habitable, making life possible for a long time.
Future of the Solar System
The future of the Solar System depends a lot on what happens to the Sun, since it is the star at the center and controls everything with its gravity and energy. Right now, the Sun is in the main part of its life, called the main sequence. During this time, it is turning hydrogen into helium through a process called nuclear fusion, which creates the light and heat Earth gets. But this would not last forever. In about 5 billion years, the Sun will start to run out of hydrogen fuel. When that happens, the core will shrink, and the outer layers will puff up, making the Sun grow much bigger. This next stage is called the red giant phase. As a red giant, the Sun will become so large that it might swallow up Mercury and Venus, and it could even reach Earth, depending on how much it expands.
When the Sun becomes a red giant, it will also start to lose a lot of its mass. This happens because strong solar winds will blow material off the Sun and into space. As the Sun gets lighter, its gravity will weaken, and the planets that survive will slowly move into wider orbits. Even if Earth is not swallowed by the Sun, it will still be in big trouble. The intense heat and radiation will likely destroy Earth's atmosphere and oceans, making it impossible for life to survive. Earth will become dry and lifeless. The inner Solar System will turn into a very dangerous and hostile place. The outer planets, like Jupiter, Saturn, Uranus, and Neptune, will probably survive, but their moons and rings might change. At some point, the core of the Sun will get hot enough to start burning helium. This process is called helium fusion. However, the Sun will only be able to burn helium for a short time compared to how long it burned hydrogen. The Sun is not big enough or heavy enough to fuse heavier elements like carbon or oxygen. So after the helium runs out, the nuclear reactions in the core will stop. Without these reactions, the Sun would not be able to hold up its outer layers.
After the Sun finishes its red giant phase, it will shed its outer layers and leave behind a small but very hot core called a white dwarf. A white dwarf is about the size of Earth, but it still holds about half the mass of the original Sun. Even though it would not make energy anymore, it will still be very hot and dense. When the Sun's outer layers float away into space, they might create a cloud of glowing gas called a planetary nebula. This is a bright shell of gas that shines in space for a short time. These outer layers are made of material that once belonged to the Sun, but now they contain heavier elements like carbon that were made inside the Sun over its lifetime. This gas will go back into the interstellar medium, the space between stars, where it can help form new stars and planets one day.
Over time, the white dwarf will cool down slowly, taking trillions of years to lose its heat. It would not shine like the Sun does now, but it will still have gravity strong enough to keep the outer planets and moons orbiting around it. However, over a very long time, the orbits of those planets might change slightly because there will be less gravity and other forces acting on them. Over an even longer period of time, tens or even hundreds of billions of years, the Solar System may start to break apart. Tiny changes, like the pull from passing stars or forces from the galaxy, can slowly change the orbits of planets and other space objects. Some planets or moons might get knocked out of the Solar System and drift off into deep space, becoming free-floating objects. Others might spiral inward and crash into the white dwarf that used to be the Sun. Eventually, the Solar System could completely fall apart, with its planets and moons scattered across the galaxy. This slow breakup is a natural part of how gravity works over a long time, and it would be the end of the Solar System.
General Characteristics of the Solar System
Overall Structure
The Solar System is held together by gravity, with the Sun at the center. The Sun is so huge that it makes up more than 99.8% of all the mass in the entire Solar System. Because of its strong gravity, all the major objects, like planets, moons, asteroids, and comets, orbit around the Sun. This setup is called the heliocentric system, which means “Sun-centered.” The Solar System is divided into different regions, and each region has its own kinds of space objects and special features.
Closest to the Sun are the terrestrial planets: Mercury, Venus, Earth, and Mars. These planets are small, rocky, and heavy, made mostly of rock and metal. This part of the Solar System is called the inner Solar System, and all the planets here are packed close together. Just past Mars is the asteroid belt. This is a doughnut-shaped area filled with many rocky objects. These space rocks did not come together to form a planet, mostly because Jupiter’s strong gravity kept pulling things apart. The asteroid belt is like a border zone between the inner rocky planets and the outer giant planets.
Farther from the Sun are the giant planets. First come Jupiter and Saturn, known as gas giants because they are made mostly of hydrogen and helium. Then come Uranus and Neptune, called ice giants because they have more icy materials like water, ammonia, and methane. These outer planets are very big, have many moons, and also have ring systems, though not all are as big as Saturn’s rings. Beyond Neptune is the Kuiper Belt, a cold, flat region full of icy objects, including dwarf planets like Pluto. There are also many tiny frozen bodies out there. Even farther away is something called the Oort Cloud. It is a giant, round cloud of icy objects that surrounds the Solar System. Scientists think this is where long-period comets come from. It is also where the Sun’s gravity starts to fade.
The objects in the Solar System are grouped into different categories based on how they move and what they are made of. First, there are the planets, like Earth and Jupiter. These are big enough to control their orbits by pulling in or pushing away other objects nearby. Next are dwarf planets, like Pluto, Eris, and Haumea. These are round like planets, but they do not clear their orbits, which means other objects still share their paths around the Sun. Then we have natural satellites, which are moons that orbit planets. Finally, there are small solar system bodies like asteroids, comets, and meteoroids. These are smaller chunks of rock, metal, or ice that travel through space in all kinds of orbits.
 Distances and scales 
The Solar System is huge, way bigger than what humans can easily imagine. The distances and sizes of the planets and other space objects are so big that it is hard to picture them using everyday ideas. The Sun is the biggest thing in the Solar System. It is so massive that it makes up almost all the mass in the entire Solar System. The Sun’s radius is about 700,000 kilometers (or 400,000 miles). Even though Earth feels big to us, about 1.3 million Earth's would fit inside the Sun. Jupiter is the largest planet. It is 5.2 times farther from the Sun than Earth and is so big that over 1,300 Earths could fit inside it. Its diameter is more than 11 times that of Earth. On the other hand, Mercury, the smallest planet, is just a little bigger than Earth’s Moon. And even smaller are dwarf planets like Pluto and tiny space rocks like comets and asteroids, which can be just a few kilometers wide.
Because the Solar System is so big, scientists use a special unit called the Astronomical Unit (AU) to measure distances in space. One AU is the average distance between the Earth and the Sun, which is about 149.6 million kilometers (or 93 million miles). Using AU makes it easier to talk about how far planets are from the Sun. For example, Venus is about 0.72 AU from the Sun, Mars is about 1.52 AU, and Neptune, the farthest main planet, is about 30 AU away. The Kuiper Belt, which contains icy objects like Pluto, stretches from around 30 AU to 50 AU. Even farther out is the Oort Cloud, a mysterious area that might reach 100,000 AU from the Sun. Usually, the farther a planet is from the Sun, the bigger the gap between it and the next planet. For instance, Venus is only about 0.33 AU farther from the Sun than Mercury, but Saturn is 4.3 AU farther out than Jupiter, and Neptune is 10.5 AU beyond Uranus. In the past, scientists tried to find patterns in these distances, like the Titius–Bode law or Kepler's ideas, but as more planets and objects were discovered, those ideas did not hold up.
There is a lot of empty space between the planets in our Solar System. Even though the planets follow paths around the Sun, the distances between them are huge compared to how big the planets are. For example, Earth is about 12,700 kilometers wide, but the closest it ever gets to Mars is around 96 million kilometers away. Because of these huge distances, even fast spacecraft take a long time, months or years, to travel between planets. The farther you go, the longer it takes. For instance, light from the Sun takes only 8 minutes to reach Earth, but it takes over 4 hours to reach Neptune. All this space makes it harder to explore and communicate with the outer planets. Sending missions to places like Neptune or beyond is a big challenge and a major achievement for science and engineering.
Some models of the Solar System are made to help people understand just how big and spread out everything really is. Since the real Solar System is way too large to picture easily, scientists and educators sometimes build scale models to shrink it down while keeping the sizes and distances in the right proportion. Some of these models are small and mechanical, like orreries, which are devices that show planets moving around the Sun. Others are huge and can stretch across cities or even entire regions. One of the biggest models is the Sweden Solar System. In it, the Avicii Arena in Stockholm represents the Sun, and it is about 110 meters wide (361 feet). In this model, Jupiter is a 7.3-meter ball (about 24 feet wide) located at an airport 40 kilometers (25 miles) away. Sedna, an object far out in the Solar System, is shown as a 10-centimeter ball (about 4 inches) placed 810 kilometers (500 miles) away. If we shrank the distance from the Sun to Neptune down to just 100 meters (about the length of a soccer field), then the Sun would only be about 3 centimeters wide (a little bigger than a marble), the giant planets would be all smaller than about 3 mm (0.12 in), and Earth and the other small planets would be tiny dots, smaller than a flea. These kinds of models help us understand that even though planets can be big, they are still tiny compared to the space between them.
Mass and Composition Distribution
The Solar System’s mass and the way its parts are spread out tell us a lot about how it formed and changed over time. Most of the Solar System’s mass, about 99.86%, is in the Sun, which is a huge ball made mostly of hydrogen and helium. The Sun’s gravity controls the movement of all the planets, asteroids, comets, and space dust. It’s incredibly massive, weighing about 1.989 × 10³⁰ kilograms. This huge mass creates a strong gravitational pull that keeps everything else in the Solar System in orbit, and it also helps determine how things spin and move. Only about 0.14% of the Solar System’s total mass is in everything else, like the eight planets, dwarf planets, moons, asteroids, objects in the Kuiper Belt, and the Oort Cloud. Out of this small portion, more than 70% is found in Jupiter, the largest planet. Jupiter weighs about 1.9 × 10²⁷ kilograms, which is 318 times heavier than Earth. Because of its size, Jupiter has a very strong gravitational pull. It affects the movement of asteroids, helps keep the orbits of other planets stable, and played a big role in clearing out leftover space rocks when the Solar System was still forming.
The giant planets, Jupiter, Saturn, Uranus, and Neptune, make up about 99% of the total mass of all the planets in the Solar System. This shows that the Solar System has a bimodal structure, meaning most of the mass is in these large gas and ice giants, not the smaller rocky planets closer to the Sun. Saturn is the second largest planet, with a mass about 95 times that of Earth. Like Jupiter, it is mostly made of hydrogen and helium, but Saturn has more ices and heavier elements deep inside. Uranus and Neptune are called ice giants. They also have atmospheres made of hydrogen and helium, but inside they have a lot of water, ammonia, and methane ices. Each of them has a mass between 14 and 17 times the mass of Earth.
On the other hand, the terrestrial (rocky) planets, Mercury, Venus, Earth, and Mars, have only a tiny amount of the Solar System’s mass. Earth makes up more than half of the total mass of these four rocky planets because it’s the biggest and densest. These inner planets are made mostly of silicate rock and metal, with common elements like iron, oxygen, silicon, and magnesium. They do not have much hydrogen or helium because, when the Solar System was forming, the area close to the Sun was too hot for light gases to stick around. The Sun’s heat pushed those gases away, so only heavier materials like rock and metal were left behind to form the inner planets.
Besides the major planets, the Solar System has many smaller objects. Even though these objects have only a small amount of mass compared to the planets, they are very important for helping scientists understand how the planets formed. One group of these small objects is the asteroid belt, which is found between Mars and Jupiter. The asteroid belt has less than 4% of the Moon’s mass, but it contains materials that were part of the early building blocks of the rocky planets. The biggest object in the belt is Ceres, which is about 940 kilometers wide. Ceres makes up about one-third of the asteroid belt’s total mass and is made mostly of rock and water ice. Farther away from the Sun is the Kuiper Belt, which holds thousands of icy objects. Some of the best-known are Pluto, Eris, Haumea, and Makemake. These objects are much smaller than the giant planets, but their mix of rock and ices like methane, nitrogen, and carbon monoxide helps scientists learn about the chemistry of the early outer Solar System. The total mass of the Kuiper Belt is only a small fraction of Earth’s mass, between 0.01 and 0.1 times the mass of Earth, because over billions of years, much of its mass was lost in space due to collisions and gravitational forces.
Even farther out is the Oort Cloud, which scientists think is a huge, round shell of icy objects surrounding the Solar System. It is believed to contain trillions of comets made mostly of water ice, carbon dioxide ice, and other frozen gases. The total mass of the Oort Cloud is not known for sure, but it might be several times the mass of Earth. It stretches as far as 100,000 astronomical units (AU) from the Sun (1 AU is the distance from Earth to the Sun). The Oort Cloud is thought to be the source of long-period comets, comets that take hundreds or thousands of years to orbit the Sun and sometimes come close enough to be seen from Earth.
Moons and rings around planets add a little bit of mass to the Solar System, but not very much compared to the planets. For example, Earth’s Moon is the fifth largest moon in the Solar System. It is pretty big compared to Earth, with a mass that is about 1.2% of Earth’s mass. The Moon is mostly made of silicate rock, which is similar to the material found in Earth’s crust and mantle. The outer planets have some very large moons too, like Ganymede, Titan, Callisto, and Io. These moons are made of a mix of rock and ice. Some of them, like Europa and Enceladus, even have oceans beneath their icy surfaces, which shows that there are many different kinds of icy, possibly habitable places beyond Earth.
The types of elements found in different parts of the Solar System also tell us a lot about how it formed. These elements were created in earlier generations of stars and then spread out into space. In the outer Solar System, there are more volatile elements (which are lighter and can turn into gas easily), while the inner Solar System has more refractory materials (which are heavier and can stay solid at high temperatures). This difference shows how temperature, sunlight, and the movement of planets affected where different materials could collect and form planets.
 Orbits of the planets 
The Earth's orbit around the Sun is nearly a perfect circle, but in a very slightly oval shaped orbit, an elliptical orbit. The other planets in the Solar System also orbit the Sun in slightly elliptical orbits. Mercury has a more elliptical orbit than the others, and there is obviously some explanation for this. Some of the smaller objects orbit the Sun in very eccentric orbits. The planets all orbit the Sun in the same direction.4-5
A full account of the planetary motion needs an account of the n-body problem, which is not treated on this wiki. A page can be found on En wiki.
 Discovery and exploration 
For thousands of years, people had no need for a name for the "Solar System". They thought the Earth stayed still at the center of everything (geocentrism). The Greek philosopher Aristarchus of Samos suggested that there was a special order in the sky. Nicolaus Copernicus was the first to develop a mathematical system that described what we now call the "Solar System". This was called a "new system of the world". In the 17th century, Galileo Galilei, Johannes Kepler and Isaac Newton began to understand physics more clearly. People began to accept the idea that the Earth is a planet that moves around the Sun, and that the planets are worlds, and that all worlds are governed by the same physical laws. More recently, telescopes and space probes sometimes let us see details directly. All inner planets have surface features. The gas giants (as the name suggests) have surfaces whose make-up is gradually being discovered.
 The eight planets 
In their order from the Sun:
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
The planets are the biggest objects that go around the Sun. It took people many years of using telescopes to find the objects that were farthest away. New planets might still be found, and more small objects are found every year. Most of the planets have moons that orbit around them just as the planets orbit the Sun. There are over 400 of these moons in the Solar System.
 Dwarf planets 
Pluto was discovered by American astronomer Clyde Tombaugh in 1930. It was declared the ninth planet of the Solar System. 
Pluto's planet status changed in 2006, when the International Astronomical Union (IAU) decided on a definition of the word "planet" for the first time. By this definition, Pluto was not a planet due to its irregular orbit and size. Thus, Pluto lost its planet status. 
Eris was first announced in 2005. It was found to be 27% more massive than Pluto. Pluto did not fit in with the rest of the planets. So, the IAU defined a new category called "dwarf planet", into which Pluto did fit, along with some other small Solar System bodies. These small bodies are sometimes called plutinos.
There is an unknown number of dwarf planets in the Solar System. As of 2025, these nine small Solar System bodies are often called dwarf planets:
 Pluto
 Ceres
 Haumea
 Eris
 Makemake
 Quaoar
 Sedna
 Orcus
 Gonggong
 Structure 
There are a few main parts of the Solar System. Here they are in order from the Sun, with the planets numbered, and dwarf planets marked with letters.
 Inner solar system 
The first four planets closest to the Sun are called the inner planets. They are small and dense terrestrial planets, with solid surfaces. They are made up of mostly rock and metal with a distinct internal structure and a similar size. Three also have an atmosphere. The study of the four planets gives information about geology outside the Earth. 
 Terrestrial planets region contains the four planets closest to the sun, all are rocky planets
 (1) Mercury
 (2) Venus
 (3) Earth
 (4) Mars
 Asteroid belt region contains;
 (a) Ceres (the only dwarf planet in this region)
 Asteroids
 Outer solar system 
 Giant planets region contains the four largest planets. Jupiter and Saturn are gas giants, while Uranus and Neptune are ice giants;
 (5) Jupiter
 (6) Saturn
 (7) Uranus
 (8) Neptune
 Trans-Neptune region 
 Kuiper belt region contains;
 (b) Pluto
 (c) Orcus
 (d) Haumea
 (e) Makemake
 (f) Quaoar
 Kuiper belt objects and possibly other dwarf planets
 short-period comets
 Scattered disc region contains;
 (g) Sedna
 (h) Gonggong
 (i) Eris
 Scattered disk objects and possibly other dwarf planets
 Oort Cloud 
The Oort cloud is separate from the trans-Neptune region, and much farther out. It contains the long-period comets.
 Ecliptic plane 
The plane of the ecliptic is defined by the Earth's orbit around the Sun. All of the planets orbit the Sun roughly around this same orbital plane. The farther away from this plane a planet orbits, the more inclined is its orbit to the ecliptic. If you could look at the Solar System "edge on" then all the planets would be orbiting more or less in the plane of the ecliptic.


World War I: World War I (WWI or WW1), also called the First World War, or the Great War, began on 28 July, 1914 and lasted until 11 November, 1918. It was a global conflict and lasted exactly 4 years, 3 months and 2 weeks. Most of the fighting was in continental Europe. 
Soldiers from many countries took part, and it changed the colonial empires of the European powers. Before World War II began in 1939, World War I was called the Great War, or the World War. 135 countries took part in World War I, and almost 10 million people died while fighting.
Before the war, European countries had formed alliances to protect themselves. However, that made them divide themselves into two groups. When Archduke Franz Ferdinand of Austria was assassinated on 28 June, 1914, Austria-Hungary blamed Serbia and declared war on it. Russia then declared war on Austria-Hungary, which set off a chain of events in which members from both groups of countries declared war on each other. 
The two sides were the Allied Powers (mainly Russia, France, the British Empire and later Italy and the United States) and the Central Powers (mainly German Empire, Austria-Hungary and the Ottoman Empire).
There was fighting in many different fronts (areas). The French and the British fought the Germans on the Western Front in France and Belgium. Germany had tried to defeat France quickly with the Schlieffen Plan but were stopped in the First Battle of the Marne. Most of the fighting on the western front was trench warfare. The Russians fought the Germans and Austro-Hungarians on the Eastern Front in Central and Eastern Europe. Fighting on the eastern front was not trench warfare as in the west, but mobile warfare. The other main areas of fighting were in the Middle East, in the Gallipoli region of the Ottoman Empire and between Italy and Austria-Hungary. Fighting also took place in southeastern Europe, Africa, China, at sea and in the air. World War I was the first major war in which tanks, airplanes and submarines (or U-boats) were important weapons.
 End 
In 1917, the Russian Revolution led to Russia leaving the war in March 1918. Also in 1917, the United States entered the war, but it took a year for most of its army to arrive. From the time of the Russian departure, before the American arrival, the Germans launched a huge attack in March 1918 to try to win the war, but it failed. 
From August to November 1918, the Allied Powers won a large victory against the Germans during the Hundred Days Offensive. Austria-Hungary and the Ottoman Empire then agreed to stop fighting. The German government collapsed, and a new government was forced to agree to stop the fighting on 11 November, 1918. Basically, the Germans ran out of men. 
Also, the influenza pandemic of 1918 had a big influence. It killed many people in Europe: it lasted for three years, from January 1918 to December 1920. About 500 million people were infected across the world which then had a population of 1.80 billion people.
The war was ended by the signing of many different treaties, the most important being the Treaty of Versailles. It also led to the creation of the League of Nations, which was meant to prevent wars. People were shocked by the size of the war, how many people it killed and how much damage it caused. They hoped it would be "the war to end all wars". Instead it led to another, larger, world war 21 years later.
 Background 
By 1914, trouble was on the rise in Europe, and many countries feared invasion from others. For example, Germany was becoming increasingly powerful, and the British Empire saw that as a threat. Countries formed alliances to protect themselves, but that divided them into two groups. Germany and Austria-Hungary had been allies since 1879 and formed the Triple Alliance with Italy in 1882. France and Russia became allies in 1894 and later formed the Triple Entente with Britain.
In 1908, Austria-Hungary had taken over Bosnia, a region next to Serbia. Some of those who lived in Bosnia were Serbs and wanted to be part of Serbia. The Black Hand was an organization that agreed with the idea and sent men to kill Archduke Franz Ferdinand of Austria while he was visiting Sarajevo, the capital of Bosnia. All of them failed to kill him with grenades while he passed through a large crowd. However, one of them, a Serbian student, Gavrilo Princip, shot him and his pregnant wife with a pistol.
Austria-Hungary blamed Serbia for the assassination. Germany supported Austria-Hungary and promised full support in case of war. Austria-Hungary sent the very harsh July Ultimatum to Serbia and threatened war unless Serbia agreed to all of its terms. Many historians think that Austria-Hungary already wanted a war with Serbia. Serbia agreed to most of the conditions, but Austria-Hungary still declared war on Serbia, which quickly led to a full-scale war. The countries had allies that entered the war in a matter of days.
Russia joined the war to help Serbia because both Serbs and Russians are Slavs. Russia began to assemble its army (mobilize), which caused Germany to begin to mobilize its forces. Germany declared war on Russia in support of Austria-Hungary and began to carry out its plan to fight a war in Europe.
Germany is in the middle of Europe and so it had to worry about enemies to its east and west. Germany's plan was the quick defeat of France in the west before Russia was ready to fight, then Germany would move its armies to the east to face Russia. However, Germany could not quickly invade France directly because France had put so many forts on the border. That made Germany invade the neighboring country of Belgium to invade France through the undefended French-Belgian border.
Britain then joined the war and said that it was to protect Belgium. However, some historians think that even if Germany had stayed out of Belgium, the British would have still joined the war to help France.
Soon, most of Europe became involved. The Ottoman Empire (now Turkey) joined the war on the side of Germany and Austria-Hungary. It is not clear why the Ottomans entered the war, but they had become friendly to Germany. Italy had allied with Germany and Austria-Hungary but refused to help them since those countries had not been attacked first. Italy noted that Austria-Hungary had attacked Serbia first. Also, Italy had long disliked Austria-Hungary and wanted to take part of its land. It later joined the war for the Allies because they had promised land across the Adriatic Sea.
 Germany against Russia 
Germany was afraid that because Austria-Hungary had attacked Serbia, Russia would attack Austria-Hungary to help Serbia. That made Germany feel that it had to help Austria-Hungary by attacking Russia first.
The problem was that Russia was allied to France, and the Germans thought that the French might attack them to help Russia. That made Germany decide that it could win the war by quickly attacking France first. The Germans could mobilize first since they had a list of all men who had to join the army, where they had to go, and the times of every train that would carry them to where they had to go.
France was slower in doing the same thing. The Germans thought that if they attacked France first, they could knock it out of the war before Russia could attack them.
Russia had a large army, but Germany mistakenly thought that it would take six weeks to mobilize and a long time before they could attack the Central Powers. However, the Russian Army mobilized in ten days and drove deep into Austria-Hungary.
In the east, the Russians attacked the Germans. The Russians pushed back the Germans, but the Germans then defeated the Russians at the Battle of Tannenberg.
 United Kingdom against Germany 
The United Kingdom quickly joined the war and said that it was to protect Belgian neutrality. Germany passed through Belgium to reach Paris before Russia could mobilize and open up a second front. On 4 August, 1914, the British declared war against Germany in support of Belgium. The British Empire was larger than any other empire and ruled over a quarter of the world. If Germany won in France, it might take British and French colonies and become the most powerful and largest empire in the world.
Britain was also worried about Germany's growing military power. Germany was developing its large army into one of the most powerful in the world. The British Army was quite small, but the Royal Navy was the largest and the best in the world, which in the 19th century was enough to keep other naval powers from attacking Britain.
Germany was a land power, and Britain was a sea power. However, Germany was building a large navy, which was seen as a threat to Britain. Germany's generals had decided that the best way to defeat France was to go through Belgium using a plan called the Schlieffen Plan by German Army Chief of Staff Alfred Von Schlieffen. The Germans could then attack the French army at the north side and the south side at the same time. The German Army went into Belgium on 4 August. The same day, the British declared war on Germany. The British had said in 1839 that they would not let Belgium be invaded, and they kept their promise.
When the Germans got to the Belgian city of Liège, the Belgians fought very hard to stop them from coming into the city. The Germans finally pushed the Belgians out of the city, but it had taken longer than the German generals had planned. The Germans then attacked the north side of the French army. The French and the British moved men up to fight the Germans because the Belgians had fought so long at Liège. However, the Germans pushed the French back at the frontiers, and the British held the Germans back at Mons, but they also fell back to join up with the retreating French Army until they were stopped at the river Marne. This was the First Battle of the Marne or "Miracle of the Marne".
The British government might have decided differently if anyone had foreseen how long the war would last and what a terrible price Britain would pay.
Most people thought that the war would be short. They thought the armies would move around quickly to attack each other and one would defeat the other without too many people getting killed. They thought the war would be about brave soldiers and did not understand how war had changed. Only a few people, such as Lord Kitchener said that the war would last long.
 Ottoman Empire 
The Ottomans joined the war because they were secretly allied to Germany, and two Ottoman warships, manned by German Navy personnel, bombarded Russian towns.
Britain fought against the Ottomans only for supporting Germany and had no other problem with them. However, by fighting them in the Mesopotamia region in what is now Iraq, in the Arabian Peninsula and in other places, Britain defeated them with the help from the British Indian Army. After the war ended, Britain got some Ottoman areas and added them to the British Empire.
Greece went into the war because its leader supported the Allied cause. Greece and Serbia had become independent, but many Greeks still lived in lands that had once been Greek but were now Ottoman. Having recently won the Balkan Wars, the Greeks wanted especially to control other land to the north that was under Bulgarian and Ottoman rule and so they declared war. The Ottomans killed most of the Greek Army as they tried to regain parts of the Ottoman Empire. Another war started when the Greeks bombed a train. The Ottomans swept the Greeks back into their own territory. From then on, the Greeks never again declared war, but the Ottomans had one of the largest armies in the world. The two main allies of the central powers in Africa were Lij Iyasu, a Muslim emperor of Abyssinia, and Sultan Diiriye Guure, the monarch of the Dervish Kingdom. The kingdom of Diiriye Guure in Taleh was destroyed in 1920, and that of Iyasu was replaced with the first female emperor Zewditu.
 Bulgaria against Serbia and Greece 
Bulgaria, like Greece and Serbia, had been part of the Ottoman Empire but later became independent. Bulgaria claimed a lot of Ottoman land. The Serbians and the Greeks felt cheated because they felt that the land belonged to them and took back the land. That angered Bulgaria and led to it becoming an Ottoman ally. Bulgaria declared war on Serbia and Greece but lost the war.
 Trench warfare 
Trench warfare killed many soldiers. New weapons, such as machine guns, and long-range artillery had an increased rate of fire that cut down huge numbers of soldiers during mass charges, a tactic left over from older warfare. The men on both sides took spades and dug holes because they did not want to be killed. The holes joined up into trenches until the lines of trenches went all the way from Switzerland to the North Sea. In front of the trenches was barbed wire to cut anyone who tried to climb over it and land mines to blow up anyone who tried to cross. Late in the war, poison gas also was an important weapon.
The new machine guns, artillery, trenches, and mines made it very difficult to attack. The generals had fought many wars without them and so they ordered their armies to attack in the old style of marching in rows, which allowed the enemy to shoot them down easily. At the 1916 Battle of the Somme, 60,000 British men died in a single day, one of the bloodiest days in the history of the British army. Late in the war, the British and French invented tanks and used them to attack entrenched Germans, but they could not make enough of them to make a big difference. The German Empire responded by making their own tanks but they had even fewer. The Germans also invented special Sturmabteilung tactics to infiltrate enemy positions. This was also too little, too late.
The British used whistles to communicate to other soldiers and so before they shelled the German trenches, they would sound the whistle. However, the Germans caught on to this tactic and so after the shelling, when the British soldiers came to finish off the German soldiers, the Germans were ready with their machine guns because they knew that the British were coming.
 Airplanes 
Airplanes were first used extensively in World War I. They were first used for reconnaissance, and pictures of enemy land were taken to help direct artillery. Generals, who are military leaders, were using airplanes as an important part of their attack plans at the end of the war. World War I showed that airplanes could be important war weapons.
Airplanes in World War I were made of wood and canvas, a type of rough cloth. They did not last long and could not fly very fast at the beginning of the war. They could only fly up to 116 kilometers per hour, or 72 miles per hour. At the end of the war, they could fly up to 222 km/h mph off, much slower than modern planes. Guns were put on planes for the first time during the war. Pilots, people who fly the plane, used the guns to shoot enemy planes. One pilot used metal sheets to armor his airplane. Other pilots began using metal sheets too. Pilots also made their airplanes better with machine guns, guns that shoot bullets much faster. That made fighting harder and more dangerous between airplanes.
Pilots had to wear certain clothes when flying an airplane in World War I because they flew high, where the air is cold. The pilots' clothes kept them warm and protected them from the wind and cold. Pilots wore a leather coat to protect their bodies, a padded helmet and goggles, which are large glasses with special lenses, to protect their head and face. They wore a scarf around their neck to keep the wind from blowing against their neck when they turned their head.
 United States against Germany 
The German leaders decided to use submarines, called U-boats, from the German word Unterseeboot (meaning "underwater boat"). The U-boats attacked passenger ships such as RMS Lusitania carrying civilians to the United Kingdom. They did not follow the laws of war because the British could easily destroy them otherwise. America was selling weapons to Germany's enemies but not to Germany and so was not neutral since the US had taken sides during the conflict. Many American and British noncombatants were killed by the submarines although they were not fighting.
Germany also wrote a secret telegram note to Mexico in code that suggest that both countries work together to attack the United States. This note is called the Zimmerman Telegram because it was sent by Arthur Zimmerman. It offered Mexico land in the Southwestern United States that the United States had taken in the Mexican-American War. British spies found out about the note and told the United States. The Americans became angry, and many decided that their country should enter the war against Germany. The Zimmermann Telegram and the sinking of American ships by German U-boats made the United States on 6 April, 1917 declare war against Germany and join the Allies.
 Russian Revolutions 
The defeat of Russia on the Eastern Front caused unrest there, which led to the Russian Revolutions. This made Russia fight both Germany and the Bolsheviks at the same time. Russia wanted to end the war against Germany and just fight the Bolsheviks in the Russian Civil War. Russia gave Germany money and land to stop the fighting between those two countries.
 First Russian Revolution 
In 1917, there was a revolution in Russia. Tsar Nicholas II had to give up power and a new government was established. At first, it was thought that Russia would fight harder now that he was gone. However, the Russians did not want to fight anymore because there was too little food, weapons or adequate roads to supply its army. The war had been putting burdens on the Russians, and many of them were poor and hungry. They began to hate their new government because it would not stop the war.
 Second Russian Revolution 
Another revolution happened in Russia in which the Mensheviks lost to the Bolsheviks (these were two rival groups of communists). The leader of the Bolsheviks was Vladimir Lenin (1870-1924). The new Bolshevik government asked the Germans for peace and signed the Treaty of Brest-Litovsk with the Central Powers in March 1918 at the city of Brest-Litovsk. Lenin later died in 1924 and was replaced by Joseph Stalin.
The Germans and Russians stopped fighting. Russia gave Germany parts of the Russian Empire in Eastern Europe and along the Baltic Sea, including the Baltic states, Poland, Ukraine and Belarus. Also, Finland gained its independence by the treaty.
 Treaty of Versailles 
After the war, the Germans had to agree to the Treaty of Versailles, which stated that Germany had to pay approximately $31.5 billion in reparations and had to take full responsibility for the war.
Also, the countries of the world were to come together to make an international organization to stop future wars: the League of Nations. The United States Senate did not agree with the League even though it was the idea of United States president Woodrow Wilson. Although Wilson tried to tell the American people to agree to join the League, the United States never joined it.
Problems with the treaty in Germany, where it was hated, later led to World War II in 1939.


Quantum mechanics: August 2023
Quantum mechanics explains how the universe works with things that are even smaller than atoms. It is also called quantum physics or quantum theory. Mechanics is the part of physics that explains how things move and quantum is the Latin word for 'how much'. A quantum of energy is the least amount possible (or the least extra amount), and quantum mechanics describes how that energy moves. 
Atoms were once believed to be the smallest pieces of matter, but modern science has shown that there are even smaller particles called subatomic particles, like protons, neutrons and electrons.August 2023 Quantum mechanics describes how the particles that make up atoms work.
Quantum physics also tells us how electromagnetic waves (like light) work. Wave–particle duality means that particles behave like waves and waves behave like particles. (They are not two kinds of things, they are something like both: this is called duality.) Much of modern physics and chemistry can be described and understood using the mathematical rules of quantum mechanics.
The math used to study subatomic particles and electromagnetic waves is very complex because they act in very strange ways.
 Waves and photons 
Photons are particles that are point-sized, tinier than atoms. Photons are like "packets" or packages of energy. Light sources such as candles or lasers produce light in bits called photons. 
The more photons a lamp produces, the brighter the light. Light is a form of energy that behaves like the waves in water or radio waves. The distance between the top of one wave and the top of the next wave is called a 'wavelength'. Each photon carries a certain amount, or 'quantum', of energy depending on its wavelength.
A light's color depends on its wavelength. The color violet (the bottom or innermost color of the rainbow) has a wavelength of about 400 nm ("nanometers") which is 0.00004 centimeters or 0.000016 inches. Photons with wavelengths of 10-400 nm are called ultraviolet (or UV) light. Such light cannot be seen by the human eye. On the other end of the visual spectrum, red light is about 700 nm. Infrared light is about 700 nm to 300,000 nm. Human eyes are not sensitive to infrared light either.
Wavelengths are not always so small. Radio waves have longer wavelengths. The wavelengths for an FM radio can be several meters in length (for example, stations transmitting on 99.5 FM are emitting radio energy with a wavelength of about 3 meters, which is about 10 feet). Each photon has a certain amount of energy related to its wavelength. The shorter the wavelength of a photon, the greater its energy. For example, an ultraviolet photon has more energy than an infrared photon.
Wavelength and frequency (the number of times the wave crests per second) are inversely proportional, which means a longer wavelength will have a lower frequency, and vice versa. If the color of the light is infrared (lower in frequency than red light), each photon can heat up what it hits. So, if a strong infrared lamp (a heat lamp) is pointed at a person, that person will feel warm, or even hot, because of the energy stored in the many photons. The surface of the infrared lamp may even get hot enough to burn someone who may touch it.
Humans cannot see infrared light, but we can feel the radiation in the form of heat. For example, a person walking by a brick building that has been heated by the sun will feel heat from the building without having to touch it.
The mathematical equations of quantum mechanics are abstract, which means it is impossible to know the exact physical properties of a particle (like its position or momentum) for sure. Instead, a mathematical function called the wavefunction provides information about the probability with which a particle has a given property. For example, the wavefunction can tell you what the probability is that a particle can be found in a certain location, but it can't tell you where it is for sure. Because of this uncertainty and other factors, you cannot use classical mechanics (the physics that describe how large objects move) to predict the motion of quantum particles.
Ultraviolet light is higher in frequency than violet light, such that it is not even in the visible light range. Each photon in the ultraviolet range has a lot of energy, enough to hurt skin cells and cause a sunburn. In fact, most forms of sunburn are not caused by heat; they are caused by the high energy of the sun's UV rays damaging your skin cells. Even higher frequencies of light (or electromagnetic radiation) can penetrate deeper into the body and cause even more damage. X-rays have so much energy that they can go deep into the human body and kill cells. Humans cannot see or feel ultraviolet light or x-rays. They may only know they have been under such high frequency light when they get a radiation burn. Areas where it is important to kill germs often use ultraviolet lamps to destroy bacteria, fungi, etc. X-rays are sometimes used to kill cancer cells.
Quantum mechanics started when it was discovered that if a particle has a certain frequency, it must also have a certain amount of energy. Energy is proportional to frequency (E ∝ f). The higher the frequency, the more energy a photon has, and the more damage it can do. Quantum mechanics later grew to explain the internal structure of atoms. Quantum mechanics also explains the way that a photon can interfere with itself, and many other things never imagined in classical physics.
 Quantization 
Max Planck discovered the relationship between frequency and energy. Nobody before had ever guessed that frequency is directly proportional to energy (this means that as one of them doubles, the other does, too). Under what are called natural units, then the number representing the frequency of a photon would also represent its energy. The equation would then be:
meaning energy equals frequency.
But the way physics grew, there was no natural connection between the units that were used to measure energy and the units commonly used to measure time (and therefore frequency). So the formula that Planck worked out to make the numbers all come out right was:
or, energy equals h times frequency. This h is a number called Planck's constant after its discoverer.
Quantum mechanics is based on the knowledge that a photon of a certain frequency means a photon of a certain amount of energy. Besides that relationship, a specific kind of atom can only give off certain frequencies of radiation, so it can also only give off photons that have certain amounts of energy.
 History 
Isaac Newton thought that light was made of very small things that we would now call particles (he referred to them as "Corpuscles"). Christiaan Huygens thought that light was made of waves. Scientists thought that a thing cannot be a particle and a wave at the same time.
Scientists did experiments to find out whether light was made of particles or waves. They found out that both ideas were right — light was somehow both waves and particles. The Double-slit experiment performed by Thomas Young showed that light must act like a wave. The Photoelectric effect discovered by Albert Einstein proved that light had to act like particles that carried specific amounts of energy, and that the energies were linked to their frequencies. This experimental result is called the "wave-particle duality" in quantum mechanics. Later, physicists found out that everything behaves both like a wave and like a particle, not just light. However, this effect is much smaller in large objects.
Here are some of the people who discovered the basic parts of quantum mechanics: Max Planck, Albert Einstein, Satyendra Nath Bose, Niels Bohr, Louis de Broglie, Max Born, Paul Dirac, Werner Heisenberg, Wolfgang Pauli, Erwin Schrödinger, John von Neumann, and Richard Feynman. They did their work in the first half of the 20th century.
 Beyond Planck 
Quantum mechanics formulae and ideas were made to explain the light that comes from glowing hydrogen. The quantum theory of the atom also had to explain why the electron stays in its orbit, which other ideas were not able to explain. It followed from the older ideas that the electron would have to fall in to the center of the atom because it starts out being kept in orbit by its own energy, but it would quickly lose its energy as it revolves in its orbit. (This is because electrons and other charged particles were known to emit light and lose energy when they changed speed or turned.)
Hydrogen lamps work like neon lamps, but neon lamps have their own unique group of colors (and frequencies) of light. Scientists learned that they could identify all elements by the light colors they produce. They just could not figure out how the frequencies were determined.
Then, a Swiss mathematician named Johann Balmer figured out an equation that told what λ (lambda, for wave length) would be:
where B is a number that Balmer determined to be equal to 364.56 nm.
This equation only worked for the visible light from a hydrogen lamp. But later, the equation was made more general:
where R is the Rydberg constant, equal to 0.0110 nm−1, and n must be greater than m.
Putting in different numbers for m and n, it is easy to predict frequencies for many types of light (ultraviolet, visible, and infared). To see how this works, go to Hyperphysics and go down past the middle of the page. (Use H = 1 for hydrogen.)
In 1908, Walter Ritz made the Ritz combination principle that shows how certain gaps between frequencies keep repeating themselves. This turned out to be important to Werner Heisenberg several years later.
In 1905, Albert Einstein used Planck's idea to show that a beam of light is made up of a stream of particles called photons. The energy of each photon depends on its frequency. Einstein's idea is the beginning of the idea in quantum mechanics that all subatomic particles like electrons, protons, neutrons, and others are both waves and particles at the same time. (See picture of atom with the electron as waves at atom.) This led to a theory about subatomic particles and electromagnetic waves called wave-particle duality. This is where particles and waves were neither one nor the other, but had certain properties of both.
In 1913, Niels Bohr came up with the idea that electrons could only take up certain orbits around the nucleus of an atom. Under Bohr's theory, the numbers called m and n in the equation above could represent orbits. Bohr's theory said electrons could begin in some orbit m and end up in some orbit n, or an electron could begin in some orbit n and end up in some orbit m. If a photon hits an electron, its energy will be absorbed, and the electron will move to a higher orbit because of that extra energy. Under Bohr's theory, if an electron falls from a higher orbit to a lower orbit, then it will have to give up energy in the form of a photon. The energy of the photon will equal the energy difference between the two orbits, and the energy of a photon makes it have a certain frequency and color. Bohr's theory provided a good explanation of many aspects of subatomic phenomena, but failed to answer why each of the colors of light produced by glowing hydrogen (and by glowing neon or any other element) has a brightness of its own, and the brightness differences are always the same for each element.
By the time Niels Bohr came out with his theory, most things about the light produced by a hydrogen lamp were known, but scientists still could not explain the brightness of each of the lines produced by glowing hydrogen.
Werner Heisenberg took on the job of explaining the brightness or "intensity" of each line. He could not use any simple rule like the one Balmer had come up with. He had to use the very difficult math of classical physics that figures everything out in terms of things like the mass (weight) of an electron, the charge (static electric strength) of an electron, and other tiny quantities. Classical physics already had answers for the brightness of the bands of color that a hydrogen lamp produces, but the classical theory said that there should be a continuous rainbow, and not four separate color bands. Heisenberg's explanation is:
There is some law that says what frequencies of light glowing hydrogen will produce. It has to predict spaced-out frequencies when the electrons involved are moving between orbits close to the nucleus (center) of the atom, but it also has to predict that the frequencies will get closer and closer together as we look at what the electron does in moving between orbits farther and farther out. It will also predict that the intensity differences between frequencies get closer and closer together as we go out. Where classical physics already gives the right answers by one set of equations the new physics has to give the same answers but by different equations.
Classical physics uses the mathematical methods of Joseph Fourier to make a math picture of the physical world, It uses collections of smooth curves that go together to make one smooth curve that gives, in this case, intensities for light of all frequencies from some light. But it is not right because that smooth curve only appears at higher frequencies. At lower frequencies, there are always isolated points and nothing connects the dots. So, to make a map of the real world, Heisenberg had to make a big change. He had to do something to pick out only the numbers that would match what was seen in nature. Sometimes people say he "guessed" these equations, but he was not making blind guesses. He found what he needed. The numbers that he calculated would put dots on a graph, but there would be no line drawn between the dots. And making one "graph" just of dots for every set of calculations would have wasted lots of paper and not have gotten anything done. Heisenberg found a way to efficiently predict the intensities for different frequencies and to organize that information in a helpful way.
Just using the empirical rule given above, the one that Balmer got started and Rydberg improved, we can see how to get one set of numbers that would help Heisenberg get the kind of picture that he wanted:
The rule says that when the electron moves from one orbit to another it either gains or loses energy, depending on whether it is getting farther from the center or nearer to it. So we can put these orbits or energy levels in as headings along the top and the side of a grid. For historical reasons the lowest orbit is called n, and the next orbit out is called n - a, then comes n - b, and so forth. It is confusing that they used negative numbers when the electrons were actually gaining energy, but that is just the way it is.
Since the Rydberg rule gives us frequencies, we can use that rule to put in numbers depending on where the electron goes. If the electron starts at n and ends up at n, then it has not really gone anywhere, so it did not gain energy and it did not lose energy. So the frequency is 0. If the electron starts at n-a and ends up at n, then it has fallen from a higher orbit to a lower orbit. If it does so then it loses energy, and the energy it loses shows up as a photon. The photon has a certain amount of energy, e, and that is related to a certain frequency f by the equation e = h f. So we know that a certain change of orbit is going to produce a certain frequency of light, f. If the electron starts at n and ends up at n - a, that means it has gone from a lower orbit to a higher orbit. That only happens when a photon of a certain frequency and energy comes in from the outside, is absorbed by the electron and gives it its energy, and that is what makes the electron go out to a higher orbit. So, to keep everything making sense, we write that frequency as a negative number. There was a photon with a certain frequency and now it has been taken away.
So we can make a grid like this, where f(a←b) means the frequency involved when an electron goes from energy state (orbit) b to energy state a (Again, sequences look backwards, but that is the way they were originally written.):
Grid of f
Heisenberg did not make the grids like this. He just did the math that would let him get the intensities he was looking for. But to do that he had to multiply two amplitudes (how high a wave measures) to work out the intensity. (In classical physics, intensity equals amplitude squared.) He made an odd-looking equation to handle this problem, wrote out the rest of his paper, handed it to his boss, and went on vacation. Dr. Born looked at his funny equation and it seemed a little crazy. He must have wondered, "Why did Heisenberg give me this strange thing? Why does he have to do it this way?" Then he realized that he was looking at a blueprint for something he already knew very well. He was used to calling the grid or table that we could write by doing, for instance, all the math for frequencies, a matrix. And Heisenberg's weird equation was a rule for multiplying two of them together. Max Born was a very, very good mathematician. He knew that since the two matrices (grids) being multiplied represented different things (like position (x,y,z) and momentum (mv), for instance), then when you multiply the first matrix by the second you get one answer and when you multiply the second matrix by the first matrix you get another answer. Even though he did not know about matrix math, Heisenberg already saw this "different answers" problem and it had bothered him. But Dr. Born was such a good mathematician that he saw that the difference between the first matrix multiplication and the second matrix multiplication was always going to involve Planck's constant, h, multiplied by the square root of negative one, i. So within a few days of Heisenberg's discovery they already had the basic math for what Heisenberg liked to call the "indeterminacy principle." By "indeterminate" Heisenberg meant that something like an electron is just not pinned down until it gets pinned down. It is a little like a jellyfish that is always squishing around and cannot be "in one place" unless you kill it. Later, people got in the habit of calling it "Heisenberg's uncertainty principle," which made many people make the mistake of thinking that electrons and things like that are really "somewhere" but we are just uncertain about it in our own minds. That idea is wrong. It is not what Heisenberg was talking about. Having trouble measuring something is a problem, but it is not the problem Heisenberg was talking about.
Heisenberg's idea is very hard to grasp, but we can make it clearer with an example. First, we will start calling these grids "matrices," because we will soon need to talk about matrix multiplication.
Suppose that we start with two kinds of measurements, position (q) and momentum (p). In 1925, Heisenberg wrote an equation like this one:
 (Equation for the conjugate variables momentum and position)
He did not know it, but this equation gives a blueprint for writing out two matrices (grids) and for multiplying them. The rules for multiplying one matrix by another are a little messy, but here are the two matrices according to the blueprint, and then their product:
Matrix of p
Matrix of q
The matrix for the product of the above two matrices as specified by the relevant equation in Heisenberg's 1925 paper is:
Where:
A=p(n←n-a)*q(n-a←n-b)+p(n←n-b)*q(n-b←n-b)+p(n←n-c)*q(n-c←n-b)+.....
B=p(n-a←n-a)*q(n-a←n-c)+p(n-a←n-b)*q(n-b←n-c)+p(n-a←n-c)*q(n-c←n-c)+.....
C=p(n-b←n-a)*q(n-a←n-d)+p(n-b←n-b)*q(n-b←n-d)+p(n-b←n-c)*q(n-d←n-d)+.....
and so forth.
If the matrices were reversed, the following values would result:
A=q(n←n-a)*p(n-a←n-b)+q(n←n-b)*p(n-b←n-b)+q(n←n-c)*p(n-c←n-b)+.....
B=q(n-a←n-a)*p(n-a←n-c)+q(n-a←n-b)*p(n-b←n-c)+q(n-a←n-c)*p(n-c←n-c)+.....
C=q(n-b←n-a)*p(n-a←n-d)+q(n-b←n-b)*p(n-b←n-d)+q(n-b←n-c)*p(n-d←n-d)+.....
and so forth.
Note how changing the order of multiplication changes the numbers, step by step, that are actually multiplied.
 Beyond Heisenberg 
The work of Werner Heisenberg seemed to break a log jam. Very soon, many different other ways of explaining things came from people such as Louis de Broglie, Max Born, Paul Dirac, Wolfgang Pauli, and Erwin Schrödinger. 
The math used by Heisenberg and earlier people is not very hard to understand, but the equations quickly grew very complicated as physicists looked more deeply into the atomic world.
 Further mysteries 
In the early days of quantum mechanics, Albert Einstein suggested that if it were right then quantum mechanics would mean that there would be "spooky action at a distance." It turned out that quantum mechanics was right, and that what Einstein had used as a reason to reject quantum mechanics actually happened. This kind of "spooky connection" between certain quantum events is now called "quantum entanglement".
When an experiment brings two things (photons, electrons, etc.) together, they must then share a common description in quantum mechanics. When they are later separated, they keep the same quantum mechanical description or "state." In the diagram, one characteristic (e.g., "up" spin) is drawn in red, and its mate (e.g., "down" spin) is drawn in blue. The purple band means that when, e.g., two electrons are put together the pair shares both characteristics. So both electrons could show either up spin or down spin. When they are later separated, one remaining on Earth and one going to some planet of the star Alpha Centauri, they still each have both spins. In other words, each one of them can "decide" to show itself as a spin-up electron or a spin-down electron. But if later on someone measures the other one, it must "decide" to show itself as having the opposite spin.
Einstein argued that over such a great distance it was crazy to think that forcing one electron to show its spin would then somehow make the other electron show an opposite characteristic. He said that the two electrons must have been spin-up or spin-down all along, but that quantum mechanics could not predict which characteristic each electron had. Being unable to predict, only being able to look at one of them with the right experiment, meant that quantum mechanics could not account for something important. Therefore, Einstein said, quantum mechanics had a big hole in it. Quantum mechanics was incomplete.
Later, it turned out that experiments showed that it was Einstein who was wrong.
 Heisenberg uncertainty principle 
In 1925, Werner Heisenberg described the Uncertainty principle, which says that the more we know about where a particle is, the less we can know about how fast it is going and in which direction. In other words, the more we know about the speed and direction of something small, the less we can know about its position. Physicists usually talk about the momentum in such discussions instead of talking about speed. Momentum is just the speed of something in a certain direction times its mass.
The reason behind Heisenberg's uncertainty principle says that we can never know both the location and the momentum of a particle. Because light is an abundant particle, it is used for measuring other particles. The only way to measure it is to bounce the light wave off of the particle and record the results. If a high energy, or high frequency, light beam is used, we can tell precisely where it is, but cannot tell how fast it was going. This is because the high energy photon transfers energy to the particle and changes the particle's speed. If we use a low energy photon, we can tell how fast it is going, but not where it is. This is because we are using light with a longer wavelength. The longer wavelength means the particle could be anywhere along the stretch of the wave.
The principle also says that there are many pairs of measurements for which we cannot know both of them about any particle (a very small thing), no matter how hard we try. The more we learn about one of such a pair, the less we can know about the other.
Even Albert Einstein had trouble accepting such a bizarre concept, and in a well-known debate said, "God does not play dice".
To this, Danish physicist Niels Bohr famously responded, "Einstein, don't tell God what to do".
 Uses of quantum mechanics 
Electrons surround every atom's nucleus. Chemical bonds link atoms to form molecules. A chemical bond links two atoms when electrons are shared between those atoms. Thus quantum mechanics is the physics of the chemical bond and of chemistry. Quantum mechanics helps us understand how molecules are made, and what their properties are.
Quantum mechanics can also help us understand big things, such as stars and even the whole universe. Quantum mechanics is a very important part of the theory of how the universe began called the Big Bang.
Everything made of matter is attracted to other matter because of a fundamental force called gravity. Einstein's theory that explains gravity is called the theory of general relativity. A problem in modern physics is that some conclusions of quantum mechanics do not seem to agree with the theory of general relativity.
Quantum mechanics is the part of physics that can explain why all electronic technology works as it does. Thus quantum mechanics explains how computers work, because computers are electronic machines. But the designers of the early computer hardware of around 1950 or 1960 did not need to think about quantum mechanics. The designers of radios and televisions at that time did not think about quantum mechanics either. However, the design of the more powerful integrated circuits and computer memory technologies of recent years does require quantum mechanics.
Quantum mechanics has also made possible technologies such as:
 Spectroscopy
 Lasers
 MRIs
 CDs and DVDs
 Why quantum mechanics is hard to learn 
Quantum mechanics is a challenging subject for several reasons:
 Quantum mechanics explains things in very different ways from what we learn about the world when we are children.
 Understanding quantum mechanics requires more mathematics than algebra and simple calculus. It also requires matrix algebra, complex numbers, probability theory, and partial differential equations.
 Physicists are not sure what some of the equations of quantum mechanics tell us about the real world.
 Quantum mechanics suggests that atoms and subatomic particles behave in strange ways, completely unlike anything we see in our everyday lives.
 Quantum mechanics describes things that are extremely small, so we cannot see some of them without special equipment, and we cannot see many of them at all.
Quantum mechanics describes nature in a way that is different from how we usually think about science. It tells us how likely to happen some things are, rather than telling us that they certainly will happen.
One example is Young's double-slit experiment. If we shoot single photons (single units of light) from a laser at a sheet of photographic film, we will see a single spot of light on the developed film. If we put a sheet of metal in between, and make two very narrow slits in the sheet, when we fire many photons at the metal sheet, and they have to go through the slits, then we will see something remarkable. All the way across the sheet of developed film we will see a series of bright and dark bands. We can use mathematics to tell exactly where the bright bands will be and how bright the light was that made them, that is, we can tell ahead of time how many photons will fall on each band. But if we slow the process down and see where each photon lands on the screen we can never tell ahead of time where the next one will show up. We can know for sure that it is most likely that a photon will hit the center bright band, and that it gets less and less likely that a photon will show up at bands farther and farther from the center. So we know for sure that the bands will be brightest at the center and get dimmer and dimmer farther away. But we never know for sure which photon will go into which band.
One of the strange conclusions of quantum mechanics theory is the "Schrödinger's cat" effect. Certain properties of a particle, such as their position, speed of motion, direction of motion, and "spin", cannot be talked about until something measures them (a photon bouncing off of an electron would count as a measurement of its position, for example). Before the measurement, the particle is in a "superposition of states," in which its properties have many values at the same time. Schrödinger said that quantum mechanics seemed to say that if something (such as the life or death of a cat) was determined by a quantum event, then its state would be determined by the state that resulted from the quantum event, but only at the time that somebody looked at the state of the quantum event. In the time before the state of the quantum event is looked at, perhaps "the living and dead cat (pardon
the expression) [are] mixed or smeared out in equal parts."
 Reduced Planck's constant
People often use the symbol , which is called "h-bar." . H-bar is a unit of angular momentum. When this new unit is used to describe the orbits of electrons in atoms, the angular momentum of any electron in orbit is always a whole number.
 Example 
The particle in a 1-dimensional well is the most simple example showing that the energy of a particle can only have specific values. The energy is said to be "quantized."
The well has zero potential energy inside a range and has infinite potential energy everywhere outside that range. For the 1-dimensional case in the direction, the time-independent Schrödinger equation can be written as:
Using differential equations, we can figure out that can be written as
or as
  (by Euler's formula).
The walls of the box mean that the wavefunction must have a special form. The wavefunction of the particle must be zero anytime the walls are infinitely tall. At each wall:
Consider x = 0
 sin 0 = 0, cos 0 = 1. To satisfy the cos term has to be removed. Hence D = 0
Now consider: 
 at , 
 If then for all x. This solution is not useful.
 therefore must be true, giving us
We can see that must be an integer. This means that the particle can only have special energy values and cannot have the energy values in between. This is an example of energy "quantization."


Biology: Biology is the science that studies life, living things, and the evolution of life. Living things include animals, plants, fungi (such as mushrooms), and microorganisms such as bacteria and archaea.
The term 'biology' is relatively modern. It was introduced in 1799 by a physician, Thomas Beddoes.
People who study biology are called biologists. Biology looks at how animals and other living things behave and work, and what they are like. Biology also studies how organisms react with each other and the environment. It has existed as a science for about 200 years, and before that it was called "natural history". Biology has many research fields and branches. Like all sciences, biology uses the scientific method. This means that biologists must be able to show evidence for their ideas and that other biologists must be able to test the ideas for themselves.
Biology attempts to answer questions such as:
 "What are the characteristics of this living thing?" (comparative anatomy)
 "How do the parts work?" (physiology)
 "How should we group living things?" (classification, taxonomy)
 "What does this living thing do?" (behaviour, growth)
 "How does inheritance work?" (genetics)
 "What is the history of life?" (palaeontology)
 "How do living things relate to their environment?" (ecology)
Modern biology is influenced by evolution, which answers the question: "How has the living world come to be as it is?"
History
The word biology comes from the Greek word βίος (bios), "life", and the suffix -λογία (logia), "study of".
Branches
 Algalogy
 Anatomy
 Arachnology
 Bacteriology
 Biochemistry
 Biogeography
 Biophysics
 Botany
 Bryology
 Cell biology
 Cytology
 Dendrology
 Developmental biology
 Ecology
 Endocrinology
 Entomology
 Embryology
 Ethology
 Evolution / Evolutionary biology
 Genetics / Genomics
 Herpetology
 Histology
 Human biology / Anthropology / Primatology
 Ichthyology
 Limnology
 Mammalology
 Marine biology
 Microbiology / Bacteriology
 Molecular biology
 Morphology
 Mycology / Lichenology
 Ornithology
 Palaeontology
 Parasitology
 Phycology
 Phylogenetics
 Physiology
 Taxonomy
 Virology
 Zoology


Moon: The Moon, also known as Luna, is Earth's only natural satellite (the only object which orbits the Earth and is not man-made). It is usually visible in the night sky, but is sometimes seen during the day.
The Moon is about one-fourth of the width of Earth. Because it is so far away it looks small in the sky, about half a degree wide.
The gravity on the Moon is one-sixth of the Earth's gravity. It means that an object will be one-sixth as heavy on the Moon compared to Earth. 
The Moon is a rocky and dusty place. It moves slowly away from the Earth at a rate of 3.8 centimeters per year due to the effect of tidal dissipation.
Some other planets also have moons or natural satellites. The giant impact hypothesis is a common explanation for how the Moon formed.
 Origin 
The giant impact hypothesis is the most common theory among scientists to explain how the Moon formed. According to this hypothesis, Earth collided with a Mars-sized proto-planet around 4.5 billion years ago, and the debris from the collision created the Moon.
Recent research has challenged this hypothesis. According to one article:[N]ew findings suggest that the Moon was primarily created from material ejected from Earth’s mantle, with minimal contribution from [the proto-planet].
 Characteristics 
 Gravity 
Because it is smaller, the Moon has only 1/6 of the gravity on Earth. So if a person weighs 60 kilograms on Earth, the person would only weigh 10 kilograms on the Moon. 
Even though the Moon's gravity is weaker than the Earth's gravity, it is still there. If a person dropped a ball while standing on the Moon, it would still fall down. However, it would fall much more slowly. A person who jumped as high as possible on the Moon would jump higher than on Earth, but still fall back to the ground. 
Because the Moon has no atmosphere, there is no air resistance, so a feather will fall as fast as a hammer.
 Atmosphere 
 Heat & cold 
Without an atmosphere, the Moon's environment is not protected from heat or cold. Astronauts wore spacesuits to survive and carried oxygen to breathe. These suits weighed about as much as the astronauts (though they were not as heavy as on Earth because of the Moon's weak gravity). The astronauts never took their gloves or spacesuits off on the Moon.
 Light 
On the Earth, the sky is blue because the Sun's blue rays bounce off the gases in the atmosphere. This makes it look like blue light is coming from the sky. On the Moon, there is no atmosphere for light to bounce off. This means the sky looks black, even in the daytime. 
 Craters 
Earth's atmosphere causes most meteorites (space rocks) to burn up. The Moon does not have this protection. Meteorites crash into it and create wide, shallow holes called craters. The Moon has thousands of them. Newer craters overlie older ones. 
 Water 
In 2009 Chandrayaan-1, India's first lunar exploration mission, found a lot of water on the Moon. However, the water is not liquid; it is in the form of hydrates and hydroxides. Liquid water cannot exist on the Moon because photodissociation quickly breaks down the molecules. However, based on the data received from Chandrayaan-1, liquid surface water may have once existed on the Moon.
 Phases 
Because the Moon is round, half of it is lit up by the Sun. As it goes around (or orbits) the Earth, sometimes the side that people on Earth can see is all lit brightly. Other times only a small part of the side we see is lit. 
This is because the Moon does not send out its own light. People only see the parts that are being lit the eclipse by the sunlight. These different stages are called Phases of the Moon.
It takes the Moon about a month (29 days, 12 hours, and 44 minutes) to complete the cycle, from big and bright to small and dim and back to big and bright. People throughout history have used the Moon's cycles to measure time.
The phases of the Moon are, in order:
 The "new Moon" (when the Moon passes between the Earth and Sun)
 The "waxing crescent"
 The "first quarter"
 The "waxing gibbous"
 A "full Moon" (when the Moon and Sun are on opposite sides of the Earth) 
 The "waning gibbous"
 The "third quarter"
 The "waning crescent",
 A new Moon again
 Tidal locking 
The Moon always shows the same side to Earth. Astronomers call this phenomenon tidal locking. This means that half of it can never be seen from Earth. The side facing away from Earth is called the far side or dark side of the Moon even though the Sun does shine on it—we just never see it lit.
 Exploration 
 Robots 
Before people stood on the Moon, the United States and the USSR sent robots to the Moon. Some of these robots orbited the Moon; others landed on its surface. The robots were the first man-made objects to touch the Moon.
 The first humans 
Humans finally landed on the Moon on July 21, 1969. Astronauts Neil Armstrong and Buzz Aldrin landed their lunar ship (the Eagle) on the surface of the Moon. Then, as half the world watched him on television, Armstrong climbed down the ladder of the Eagle and was the first human to touch the Moon as he said, "That's one small step for a man, one giant leap for mankind."
Even though their footprints were left on the Moon a long time ago, they could remain there for millions of years. There is no wind or rain on the Moon, so erosion happens extremely slowly. This means the footprints do not get filled in or smoothed out like they would on Earth.
 Future landings 
Ten more astronauts landed on the moon between 1969 and 1972. All were part of the United States' Apollo program.
The last spaceship to land on the Moon was Apollo 17. Eugene Cernan was the last person to touch its surface.
 Legal status 
During the Cold War, the United States Army thought about making a military base on the Moon so they could attack targets on Earth. They also considered testing a nuclear weapon on the Moon. The United States Air Force had similar plans. However, both plans were brushed off as NASA moved from a military agency to a civilian-based one.
Even though the Soviet Union left remains on the Moon, and the United States left a few flags, no country has control over the Moon. The U.S., the Soviet Union, and many other countries signed the Outer Space Treaty, which calls the Moon and all of outer space the "province of all mankind". This treaty also bans all use of the military on the Moon, including nuclear weapons tests and military bases.
Timekeeping
As of 2025's first quarter, there is no time standard on the Moon. The U.S. government has suggested Coordinated Lunar Time.


Nudity: Nudity (or nakedness) is when a human is not wearing clothing.
Humans evolved to be mostly hairless. All other primates have fur. Modern humans evolved about 300,000 years ago, and continued to be naked until they made the first clothing, 100,000 years ago. Before clothing, humans decorated their bodies with jewelry, paint, tattoos, and scars. They made belts and bags to carry tools. They made masks and disguises to be less visible while hunting. When they moved out of Africa, people used the same crafts to make things to cover their bodies. They did this to both protect them from the cold and also to protect them from the dust and sun of the desert. Humans wear decorations and clothes as nonverbal communication. It shows their personality and group membership. In the modern world, there can be many rules about nudity. Traditional Jewish, Christian, and Muslim people dress modestly. They are never without clothes in places where other people can see them. This may not include their spouses or family members of the same gender. Someone might be embarrassed for being seen naked.
Naturists believe being nude is good for health and well-being. Nudity might be a normal part of life in places like the Netherlands, Scandinavia, Japan, and Germany. 
Other words for nudity
With so many ways of thinking about nudity, there are also many words to use. In English, nude and naked both mean being unclothed, but sometimes have different meanings. Nude is from Norman French. Naked is from Anglo-Saxon. Being naked may mean not being fully dressed. Stark naked means to have no clothes at all. Being nude is more about the social meaning of not having clothes. There are euphemisms for nudity such as "birthday suit," "in the altogether," and "in the buff." Partial nudity usually does not cover parts of the body thought of as sexual. This includes the buttocks and the female breasts.
Functional nudity is when a person is nude by necessity, such as when group bathing or changing clothes in a locker room. A similar idea is called contextual nudity, which says that nudity may be normal only at a particular time and place, such as during medical treatment.
The nude is used to talk about unclothed people in works of art. In 1956, art historian Kenneth Clark wrote a book, "The Nude: A Study in Ideal Form," in which he says the nude in art may be beautiful, but being naked in real life is embarrassing. In 1972, artist and art critic John Berger said almost the opposite: that the nude in art is voyeurism, but being naked in real life is to be one's true self. 
 Why did humans lose their hair? 
The loss of body hair was one of a group of adaptations that are part of human evolution. Modern humans evolved in Africa from hunter-gatherers in terrain different from where hominins had lived before. There were fewer trees and more exposure to the Sun. Sweat drying on bare skin cooled the body better when hunting for food, so less hairy hominins survived.
Because the brain produces a lot of heat, better cooling of the body favors an increase in brain size. Early humans had learned to make tools and weapons, those with larger brains made them better. On the other hand, human heads are more vulnerable. In adapting to running and carrying weapons, humans became fully upright. Being upright was good for mothers to carry their babies, who no longer had fur to cling to. Being smarter and having their hands free, humans could also make better tools. Intelligence is a better reason. Being upright also reduced Sun exposure except for the top of the head, which remained covered with hair. Skin became darker as protection from the Sun.
Humans with modern bodies first existed between 350,000 and 260,000 years ago. They were large-brained, walked upright, had dark skin, and were naked. Modern human behaviors, such as making art, burying the dead, and wearing clothes began at least 100,000 years later. These behaviors were the beginnings of human culture.
One of the earliest works of art known is the Venus of Willendorf, a small statuette of a nude woman. The face of the woman is not visible. The belly of the woman as well as her breasts are exaggerated. It is not known what the statuette meant to the people who made it, or what importance it had.
Prehistory of clothing
There are many questions about the beginnings of clothing because little remains of the plant and animal materials used for clothing many thousands of years ago. What has been found are the stone and bones tools and some of the things made with them. An example is the shells with holes made to string into a necklace. Making string and a tool to make a small hole are some of the same technology needed to make clothing.
Humans migrated out of Africa during periods of warmer weather. During the last ice age, clothing was needed to survive in some of these places. Close-fitting clothes that hold in the heat of the body could not be made until people had the tools needed. The first sewing needles were found with the remains of cro-magnon people who lived about 40,000 years ago.
Another way of dating the origin of clothing is based upon the genetic difference between human head lice and the lice that live in clothing. A study shows that wearing clothes most of the time may have begun between 83,000 years ago and 170,000 years ago. This could mean that the use of clothing began before migration out of Africa, allowing humans to do so.
Clothing has become the customary covering for humans, but not for everyone at all times. In prehistory, clothes were worn only when needed to stay warm. Hunter-gatherers in the topics were naked most of the time, and are today in the remaining isolated communities.
Before clothing, people had ornamented their bodies with jewelry, scarification, tattoos, and body painting. Different ornaments and clothing showed both individuality and group membership. More and better clothing and ornaments were worn by people in higher positions in society. For many thousands of years, humans lived in tribes of about 150 individuals. They rarely met strangers. When populations grew, people began living in contact with larger groups. They met others that they did not know. The difference between private and public places began. Clothing and ornamentation worn in public became important to show others who they were and their position in the society.
Early civilization
At the end of prehistory, between 7 and 9 thousand years ago, people began to settle in one place, becoming the first civilizations. As civilizations became larger, clothing became more important to show social position. A Roman citizen wore a toga in public but was nude at the public baths. Not dressing properly might be uncomfortable, but not shameful. Only members of the Abrahamic religions; Judaism, Christianity, and Islam
believed that everyone feels shame about nudity and sex.
Early civilizations valued the naked body. Many made images of their deities as perfect humans without clothing. In Ancient Greek mythology, although male gods ruled, goddesses were the source of life. Gaia was mother of the titan Prometheus who created man out of mud, and the goddess Athena breathed life into his creation. The creation story of the Abrahamic religions begins with nudity as innocence that becomes shame with knowledge of good and evil. In present Western cultures, with both the Greek and Abrahamic history, nudity is thought of as shameful by some but by others as natural, innocent and beautiful.
 Early civilizations: Nude deities 160 160
  File:Lilith Periodo de Isin Larsa y Babilonia.JPG
 Statue of a Babylonian female deity
 The Burney Relief, First Babylonian Dynasty (about 1800 BC)
  File:7262 - Piraeus Arch. Museum, Athens - The Piraeus Apollo - Photo by Giovanni Dall'Orto, Nov 14 2009.jpg
 The Piraeus Apollo
  Apollo, one of the Greek gods of Olympia, 530-500 BC
  File:Greek Marble Statue of Aphrodite Anadyomene (Hair-Binding).jpg
 Marble statue of Aphrodite Anadyomene
  Aphrodite, 2nd century BC
In the earliest civilizations with warm climates, only people of high social positions would be clothed at all times in public. The average person in Mesopotamia and Ancient Egypt owned a single piece of cloth that was wrapped or tied to cover the genitals. Both men and women would be bare-chested and barefooted. Herders, fishermen, and others would be naked while doing work that was hot, dirty, or wet. Those of low social position and slaves might have no clothing. Children would be naked until about age 12. It was not until the New Kingdom of Egypt that upper-class women wore dresses and ornamentation which covered their breasts. This clothing is often shown in movies and television as representing Ancient Egypt in all periods.
 Early civilizations: Everyday nudity 160 160
  File:Fetekti3c.jpg
 Fresco of ancient Egyptian workers
  Ancient Egyptian workers on white plaster, Egypt about 2500–2300 BC
  File:Fresco of a fisherman, Akrotiri, Greece.jpg
 Ancient Greek fishermen
  Painting of a fisherman on white plaster, Greece 1600–1500 BC
  File:Musicians and dancers on fresco at Tomb of Nebamun.jpg
 Ancient Egyptian entertainers
  Musicians and dancers, on a tomb in Thebes, Egypt, about 1400 BC
Many think the Ancient Greeks were often nude, but public nudity was only for religious events. Most famous are the Ancient Olympics, at which the male athletes were nude. It was not until the 5th Century BC that Spartan women were bare-chested or nude for sports.
In stories written in China as early as the fourth century BC, nudity is an insult to human dignity. The belief was that "humanness" in Chinese society is earned by correct behavior.
Colonialism and racism
Modern colonialism and racism began when Christian and Muslim people more often had contact with Indigenous peoples of the tropics. In his diaries, Christopher Columbus writes that the people of Guanahaní in the Bahamas were entirely naked, and gentle. He also thought that they were less than fully human, and could be exploited. This led to the stereotype of the "naked savage".
At first, Islam was limited to large towns. In other places, paganism continued. Traveling in Mali in the 1350s, Muslim traveler Ibn Battuta was shocked by the nudity of female slaves and servants at the court of Sultans.
European explorers in the 17th century viewed the lack of clothing they found in Africa and Oceania as showing a lower state of nature. Colonizers valued nudity in art but thought nakedness in daily life was evidence of racial inferiority. Books and articles about naked savages became popular in Europe in the 18th century in stories of Pacific island women with bare breasts. Paintings and drawings showing Pacific island women with bare breasts were also popular. In the late 19th century, paintings such as Three Tahitian Women, by Paul Gauguin in 1896, showed island women with bare breasts.
Non-western peoples during the period were naked only by Western standards, the lower body of adults were covered most of the time. Lacking the idea of shame, clothing might be removed in public for useful or symbolic purposes. Children and sometimes women until marriage might be naked as having "nothing to hide". Indigenous peoples of North America also did not think of sexuality or nudity with shame. European colonizers found that Natives thought premarital and extramarital sex, homosexuality, and cross-dressing were normal. This increased their efforts to convert Natives to Christianity. However, thinking of others as less than human could be used to justify conquest and removal.
Sexuality and gender
Gender differences in nudity are shown from the beginning of history. In the first civilizations, male gods and heroes were naked. Female deities and goddesses were nude or clothed, depending upon the religious meaning they represented. In Ancient Greek art and in life, male nudity represented freedom, masculinity, privilege, and physical virtues. In the later Hellenistic period, nude women began appearing on vases in passive activities, such as bathing. With the beginning of the Christianity, women's bodies became a threat to civilized behavior that must be covered. Male nudity was of lesser importance, and might be necessary for hard labor.
Gender and nudity 180 180
 File:Stamnos women bath Staatliche Antikensammlungen 2411.jpg
 Three young women bathing, 440–430 BCE.
 File:Joaquin Sorolla Ninos A La Orilla Del Mar.jpg
 Children at the Seashore by Joaquín Sorolla (1903)
 File:Brazilian favela woman breastfeeding.jpg
 Breastfeeding in Natal, Brazil
 File:Ivoryso2.jpg
 An ad for soap showing ordinary behavior for men in the 20th century
 File:2000-158-19 Medal, Olympics, 1920, Antwerp, Gold, Obverse (7268561188) (cropped).jpg
 Medal from the 1920 Olympics references the nudity of athletes in the Ancient Olympics
Female nudity
Thinking women are more modest, more of the female body is covered in everyday life than the male. However, it is only in modern times that nudity includes the female breasts. Breasts were thought of first for feeding babies and were symbolic of loving kindness. It was not until the 17th century in Europe that women always had to cover their breasts in public.
Women breastfeeding in public is now protected as a legal right in many countries. In others, it is forbidden. Even in countries where public breastfeeding is allowed, mothers might not do so because other people may object. Soon after becoming Pope, Francis supported women's right to breastfeed in church.
Male nudity
From 1860 to 1937 men in the US and UK wore bathing suits that covered the chest in places where women were present. When only other men or boys were present, being nude was usual for swimming and bathing until the end of the 20th century. Poor and working-class men and boys swam nude in any river, pond, or lake. Women and girls either did not swim or went in the water dressed because it was thought that they must be modest at all times. When indoor pools were first built in the 1880s male nude swimming continued until the 1960s, when pools became coed.
Private versus public
Each culture, or way of life of a group of people, is unique. However, there are things that are shared by all humans but in different ways. Anthropology studies different cultures side by side, showing both what they have in common and how they differ. These common things and their differences are the dimensions of culture. An example is the value placed on individuals or groups. Some cultures place a high value on individuality, while other cultures place a high value on community. This is the cultural dimension of individualism and collectivism. Cultures are usual somewhere between the two ends of a dimension.
In thinking about nudity, an important dimension of culture is private-public and the behavior that is normal in each.
 In some cultures, private means being entirely alone, defining personal space. In other cultures, privacy includes family and friends.
 Semi-public includes people less well known, but familiar, defining social space.
 Being in public includes everyone. The meaning of public space changed as cities grew.
People wear different amounts of clothing in private places than in public. Semi-public nudity may be necessary, such as when changing clothes or showering after work or exercise. Usual behavior when nude with others include respect for personal space and the separation of genders. In the 21st century, this everyday, non-sexual nudity has become uncomfortable. Changing ideas of gender and sexuality threaten the idea of separating the sexes. Digital photography threatens keeping any behavior private. At the same time, modern media contain more images of sexualized nudity. There are fewer ways to learn that nudity is not always sexual. There are fewer places to see ordinary people naked and learn what is normal.
Private nudity
People vary in their comfort with private nudity. A 2018 survey in the US found that 65% of millennials slept in the nude. Thirty-nine percent of baby boomers slept in the nude. In a 2014 UK survey, 51% of men and 31% of women felt comfortable nude. 26% of men and 17% of women walked about the house nude when no one else was home.
Body image is the thoughts and feelings of a person has about their own body. In Western cultures, women often want to be thinner, men more muscular. In non-western cultures, body image has a different meaning. In some societies, people think of themselves as part of a group, not as individuals. Where getting enough food is a problem, being thinner is seen as unhealthy. Westernization of cultures has resulted in an increase in body dissatisfaction worldwide.
Naturists have long claimed social nudity leads to a better body image. Naturism has not often been studied objectively, but psychologist Keon West of Goldsmiths, University of London found that social nudity reduced body anxiety and increased well-being. People with a poor body image improved after a nude social activity.
Family nudity
In research by Gordon and Schroeder many differences in parental nudity were found from family to family. According to them, "there is nothing (..) wrong with bathing with children or otherwise appearing naked in front of them". Bath time can be a chance for parents to teach children about their bodies and the bodies of others. They say that by ages five to six, children begin to become modest, and recommend being sensitive to their children's wishes. Barbara Bonner recommends against nudity in the home if children are showing troublesome sexual behavior. In a 1995 Paul Okami found nothing negative in parental nudity. Three years later, his team found that, if anything, seeing parents nude had some good effects, especially for boys.
Semi-private nudity
Most of the places where people are nude with others are semi-private. Access is limited, usually by gender (men or women only), by age (as in schools), or other factors. Most of the places for practicing naturism are semi-private, limited by membership or entry fees. There are both written rules and informal expectations that must be observed. When an entire society understands naturism, as in Germany, clothing-optional areas within public spaces become semi-private.
In places so isolated that there is little chance of being seen, it has been understood to be safe for nudity. This includes "skinny-dipping" in any body of water, and hiking in the wild. In the United States, there is no law against nudity in national parks. When places become popular with naturists, new laws have been passed.
Childhood nudity
Until recently, it was thought children had no sexual feelings, and that the nudity of children was innocent.
Very young children want to be nude, not only at home but where others can see. They touch their own bodies and look at the bodies of others. This is part of growing up, with normal behavior at each age. Parents and caregivers need to understand these changes as normal to set boundaries on behavior without teaching shame. Signs of problems include children of very different ages touching. Children need to be taught that it is never okay for an older person to touch some of their body parts. A 2018 study of Danish childcare found disagreement between caregivers who wanted to continue allowing normal childhood nudity and administrators who have begun to worry about charges of sexual abuse being made.
It is normal for children to be naked at home, including outdoors, when visitors are present. Parents who see nothing wrong with this may allow it, accepting that most children become more modest as they near puberty. In the United States, other adults may not approve, creating problems. Problems include the nude child's playmates also removing their clothes, which the other parents might not want.
In Northern Europe, children play outdoors nude in public parks and fountains. Travel writer Rick Steves writes, "When the sun's out, Scandinavian parks are packed. ...American visitors will notice a lot of nudity — topless women and naked kids." In sub-Saharan Africa, it is normal for boys and girls in rural areas to play together nude until puberty.
The naturist point of view is that children are "nudists at heart" and that naturism provides the healthiest environment for growing up. Modern psychology agrees that children can benefit from an open environment where the bodies of others their own age of both sexes are not a mystery. However, there is less agreement regarding children and adults other than parents being nude together.
Until the 1990s in the United States, public swimming pools such as at the YMCA allowed parents to bring young children into the changing rooms. The children could see adults and other children of either sex nude. There was sometimes no specific age limit for the children, but in some places up to age 6. Soon after, rules were changed allowing only same-sex use of changing rooms. At some places today, family changing rooms have been added.
Public and childhood nudity
 File:Bundesarchiv Bild 183-1983-0804-409, Kreis Angermünde, FKK-Strand.jpg
 Nudist beach at Herzsprung, Germany.
 Nudist beach at Herzsprung, Germany (1983).
 File:Bundesarchiv Bild 183-1987-0702-020, Berlin, SEZ, Duschen.jpg
 Nude children and partially nude adults at a German amusement park
 Shower at an amusement park in Berlin, Germany (1987)
 File:Bundesarchiv Bild 183-1987-0609-302, Köritz, Duschraum des Kindergartens.jpg
 Communal shower in a kindergarten
 Communal showers in an East German kindergarten (1987)
Male nudity in swim class
In the United States, male nudity was required when indoor pools were first built at the end of the 19th century. Some were built by city governments, others by the YMCA. In the 20th century, schools began to build pools. Indoor pools were more common in northern states than in the south. Boys and girls had separate classes, so the boys swam nude while the girls usually wore suits. Male nudity was nationwide due to rules from public health organizations about indoor pools. The cleanliness of the pool water was given as the reason. Women's suits were made of cotton, which could be boiled to kill germs. Men's suits were made of wool, which would shrink if boiled. In the early years, fibers from wool suits clogging pool filters were also given as a reason. Bathing suits were allowed only for public competitions. Young boys might be nude while competing in public. Clothed girls and women sometimes attended boys' team practices. Women sometimes coached boy's teams. Male nudity continued until mixed-gender classes were allowed, and slowly stopped in the US when gender equality became law with Title IX of the Education Amendments of 1972. In the 21st century, public male nude swimming is largely forgotten, or denied having ever existed.
Communal bathing
Bathing is known for its benefits to health and well-being. Many societies also bathe for purification before or after other activities. Nude bathing in natural hot springs, steam rooms, and sweat lodges have existed since the Stone Age, and are found worldwide. Public bathing is not always "open to the public". There are fees, and rules that are understood before entry. Often there is separation by gender, but not always. In Finland and Germany, mixed gender bathing or using a sauna nude is a social activity. The Japanese idea of hadaka no tsukiai, or spending time together naked, means classmates, teammates, fellow employees, families or neighbors spend time together naked for social bonding. Usually, this is while bathing at a bathhouse or onsen. As the 21st century proceeds, almost no bathhouses in Japan are mixed gender. South Korean bathhouses (Jjimjilbang) have always been gender-segregated, but nudity is required. Although there may be local differences, in the United States, it is generally understood that nudity is not allowed in public saunas. This includes being wrapped only in a towel. Instead, the rules are only about what to wear, bathing suits or loose clothing. This is true even though most US saunas are in the single-sex areas.
Until recently in Western cultures, showering after sports with others of the same sex was expected or required. In the 21st century, students in the US and UK avoid showering with their classmates. Locker rooms in American fitness clubs are installing private showers and changing rooms for millennials.
Public nudity
In different counties and localities, public nudity is a matter of common understanding of proper behavior. More often, prohibitions regarding exposing the body are written into law. The basic prohibition is outlawing exposure of the genitals in public except where it is specifically allowed. The violation is often called indecent exposure or public indecency. Public exposure of breasts, or specifically the nipples, is often included in the legal definition. Most violations are considered minor, but may be crimes when there is intent to cause distress or harm to the person viewing the nudity. Serious crime is assumed when the target of the exposure is a child. Intent is difficult to establish, but is assumed when a single individual exposes their genitals suddenly to strangers in a public place. This is often called "flashing". Such exposure may be a sign of exhibitionism, a mental disorder marked by feelings of pleasure in exposing oneself.
Some countries allow nudity for recreation. People swim nude at "clothing optional" beaches. Often the beaches are public property owned by local or national government. It is not as common in the United States and Canada as in Europe. It is common on the Mediterranean. 
There are other types of nude recreation. There are some nude bicycle tours and nude hiking. Nude hiking in the Alps is popular with German tourists. In 2009, Appenzell Innerrhoden, a small Swiss canton, voted to stop nude hiking, imposing a fine.
Nudity in public may also be allowed, depending upon the openness of a society to individual expression. Exceptions are limited to specific times, places, or other factors. Nudity that is part of artistic performance, political protest, or events such as Carnival may have their own rules.
The brief public exposure of parts of the body as a form of expression has a long history. Running through a public area naked is called "streaking". Streaking was popular in the 1970s, and has become a tradition at a few university events. Exposing the buttocks or "mooning" an enemy before battle was recorded in ancient Rome.
Naturism
Naturism (or nudism) is a cultural and political movement which began at the end of the 19th century. Followers of this movement think that nudity, both in public and in private, has many benefits. Some naturist activists seek opening public recreation areas to nudity. Others groups practice naturism within privately owned camping grounds or resorts. Private places might only allow certain people to enter. It is common to only let families join, making for a safer environment for children.
The International Naturist Federation (INF) has members in forty countries. The INF definition of naturism is "Naturism is a way of life in harmony with nature characterised by the practice of communal nudity with the intention of encouraging self-respect, respect for others and for the environment." This definition has been basically the same since the INF began in 1974.
 Nude recreation 
When they spend their time together, some people also want to do recreational acivities while they are nude. The ancient Olympic Games were nude events. Some of these activities like bathing or swimming are commonly associated with being nude. Others include sports, where people are often not naked, or big events such as the world naked bike ride. Still others, such as body painting, may be artistic in nature. 
Nudity as protest
Nude protests
  File:Femen à Paris 4.jpg
 Femen protest in Paris
  Femen protest in Paris, to support Aliaa Magda Elmahdy, an Egyptian feminist and body freedom activist
  File:SF Nude Ban Protest IMG 3752.jpg
 Protest against the San Francisco, CA ban on public nudity
  People protesting against banning nudity in San Francisco, 2013
  File:WNBR London 2012.jpg
 People taking part in the World Naked Bike Ride in London, 2012
  People taking part in the World Naked Bike Ride in London, 2012
Some people use nudity as a form of direct protest, or to attract attention to a cause not related to nudity.
In the United States, a direct protest has been women seeking the same right to be bare-chested as men. Advocates call this "topfreedom" rather than being topless. In a few local cases, this has succeeded in changing laws to allow topfree sunbathing as non-sexual, but have failed to gain full equality with men.
When the city of San Francisco, California banned nudity after many years of allowing it, there were nude protesters.
People for the Ethical Treatment of Animals (PETA) had a protest for animal rights, "I'd rather go naked than wear fur." which was so effective in reducing the use of fur in fashion that it ended after 30 years, declaring victory. At first there were naked people protesting in front of clothing stores, but changed to ads by famous people. The Femen group demonstrates topless to call attention to a number of feminist issues. The World Naked Bike Rides are done annually in many cities in the world to protest dependence on automobiles and fossil fuels.
Nudity as punishment
In any culture where being naked is shameful, being deprived of clothing can be used as punishment or torture. An example happened during the invasion of Iraq in 2003 by the United States and its allies. Members of the United States Army Reserve tortured prisoners at Abu Ghraib. Photographs were circulated that showed prisoners nude and in degrading positions.
 Functional nudity 
When people are nude because of necessity, or because it is practical, this is called functional nudity, or contextual nudity. One of these examples is that when people are changing clothes, for example, from a wet swimsuit to a dry one. In many places of the world changing-rooms and communal showers are sex-segregated. Another example of functional nudity might be when visiting a doctor. For certain examinations or treatments, the patient has to be nude. Yet another example of functional nudity is when wearing clothes might simply be impractical. People visiting a sauna sweat a lot. Wearing clothes in such a setting is impractical. That's why, in many cases, people visiting a sauna are naked, and only have a towel on which they sit. Similarly, certain people want to be naked when they practice certain sports.
 Nudity and advertising 
Nudity is also used in advertising. This is done to attract the attention of the consumer to a product, a service, or simply a certain form of advertising. That way, people who are naked sometimes distribute flyers that advertise a given product, event or service. This is often done in conjunction with body painting. Ads and the covers of magazines often show nude people, or people wearing very little clothing. This is done, even when there is no relation between people being naked, and the product or service they advertise. Advertising with nudity often works, because nudity in public is rare. Also, people do not expect to see other people nude in public. On television, there are also special programmes, where being nude is part of the attraction of the programme. 
Cultural differences
Cultural differences are based upon thoughts and behaviours that operate below the level of awareness. Emotions about being nude or seeing others nude are one set of responses. People from another culture think only in terms of their own culture, and find it difficult to understand any other way of thinking. This occurs not only for distant cultures, but also those with much in common. Americans define privacy in terms of visual space. Private or personal space means not being seen by others. Americans think anyone nude where they can be seen has "no reasonable expectation of privacy". Americans think seeing someone nude in their own home through a window is "public indecency" subject to legal action.
For Europeans, privacy is defined by a personal sense of dignity that each individual carries with them. Europeans can keep this dignity while nude on a crowded beach. This sense of privacy comes from belief that nudity is not always sexual. Europeans have the shared norm that sunbathing and swimming are not sexual. They respect others privacy by not looking directly at anyone when they are naked.
Between Western and non-Western cultures, differences are greater. Many members of Western societies think that all humans feel shame when naked, or should. The unashamed behavior of children and indigenous peoples shows that shame is learned. Living in a climate perfectly suited to humans means growing up with few clothes or none, learning they have nothing to be ashamed of. Adults in these societies dress, but are nude when it makes sense to them. Colonialism continues in other ways. Religious people seek to change other cultures to live according Western beliefs. Other western travelers visit tropical counties to see people living in what they think of as simple ways of the past.
In counties that follow Islamic law, modesty (Hijab) is demanded. There are five schools of Islamic law. In the least strict, women in public must cover their bodies except hands and face. Clothing must also be loose and solid, showing nothing of the body. The belief is that non-Mehram (unknown) men cannot control sexual thoughts when seeing any part of a woman's body. Rules of modesty include men as well, but they need to only cover themselves from navel to knees. Not doing so may be thought badly of, but it is not a crime. In some Arabic countries, women wear the Niqāb, which also covers the face, leaving only a slit for the eyes. A woman's hands are also kept out of sight as much as possible. Worn mostly in Afghanistan, the burqa adds a screen over the slit, hiding the eyes. Muslim women who are against these rules may be imprisoned. In Iran, Mahsa Amini died after being arrested by "morality police" for not covering her hair correctly. This was followed by protests against the government that continued for a few months. A report by the Iranian Forensic Organisation stated that Amini died of illness due to a childhood condition rather then any beatings or blows. The Iranian government also states that the protests were started by outsiders, not Iranian women.
Some Christians have rules of dress close to Islam, but dresses need only reach below the knees and be very modest.
Africa
The cultures and peoples of Africa are divided between north and south by the Sahara desert. Humanity originated in Southern Africa.
North Africa is mainly desert, hot and dry. The indigenous clothing is light, loose fabric covering the entire body, protecting it from sun and blowing sand, but allowing for cooling breezes. This style of dress has not changed for thousands of years. Most of the peoples in the region are Muslim. The style of dress also matches the Islamic rules of modesty.
Sub-Saharan Africa is more varied in climate. Present day clothing is highly influenced by colonialism, both Christian and Islamic. Islamic counties in the south, Somalia, Djibouti, Comoros and Mauritania observe the rules of modesty.
Dressing Africans in European clothes to cover their nakedness was part of converting them to Christianity. In Christian countries today, European dress is normal in cities. Indigenous styles have been adapted for Western modesty, especially for women.
 Indigenous African dress
  File:Reed Dance Festival 2006-001.jpg
 A Swazi woman at the Reed Dance ceremony – 2006
  A Swazi woman participating in the Umhlanga ceremony in Eswatini – 2006
  File:Junge Hamer in Südäthiopien.jpg
 Young Hamer woman in southern Ethiopia (near Turmi) – 2006
  Young Hamer woman in southern Ethiopia – 2006
  File:Himba-Hirten.jpg
 Himba herders the Kaokoveld desert
  Himba herders the Kaokoveld desert
In rural areas, some tribes continue to be nude according to tradition. Some tribes are returning to pre-colonial dress for some events. In certain Togolese tribal areas, it is common for big families to not wear any clothes at all for certain festivities. Others do not wear any clothes below the waist. This makes it possible for young men to see women and girls whom they may marry. Stick-fighting tournaments are very popular places to do this. The Ugandan Kavirondo tribes are a mix of Bantu and Nilotic immigrants. Traditionally, they went mostly naked. Over time, the men began wearing clothing similar to men in western culture.
Asia
In much of Asia, traditional clothing covers as much of the body as in Europe. However, the emotion felt in being improperly dressed is social embarrassment, not shame about sex.
The mixed gender bathing culture of Japan is not thought of as public nudity, but private in the context of a communal culture. In world surveys of how likely people are to be nude on a beach, Japan is lowest at 4%. During the Meiji era (1868–1912) there had been attempts to eliminate Japan's normal states of undress due to leader's concerned with Japan's international reputation. Although often ignored, the law against public undress had the effect of sexualizing the body where it had not been erotic.
In India, some members of the Hindu and Jain religions reject all worldly possessions, including clothing.
Europe
European history
For a thousand years after the fall of the Roman Empire, proper behavior in Europe was defined by the Catholic Church. The church disapproved of sexual behavior outside of marriage, but was more tolerant of nudity than other Abrahamic religions. Sexual segregation was expected, but not required. Everyone other than the upper classes lived in close quarters and had more tolerance for functional nudity, sleeping and bathing without privacy. Until the Carolingian era, Christians were baptized naked to show that they emerged without sin. Small groups of Christians held worship services in the nude, reclaiming the innocence of man before the fall.
The nude had been a subject of European art since the ancient Greeks, which continued in the Roman era. With the rise of Christianity, nudity almost disappeared from art during the Middle Ages, except for Biblical stories such as Adam and Eve. Symbolic nudity in the fine arts increased in the Renaissance, with paintings and sculpture based upon classical mythology and Biblical scenes. The rediscovery of ancient Greek culture had increased the conflicting views of nudity as good or bad.
Nudity in European art
 File:David von Michelangelo.jpg
 Michelangelo's David
 Michelangelo's David (1504)
  File:Apollo and Daphne (Bernini) (cropped).jpg Apollo and Daphne (1622) by Gian Lorenzo Bernini
  File:Artemisia Gentileschi - Sleeping Venus.JPG Venus and Cupid (Sleeping Venus) (1625—1630), a rare painting by a female artist, Artemisia Gentileschi
  File:Rembrandt Harmensz. van Rijn 016.jpg Bathsheba at Her Bath (1654) by Rembrandt with his wife as the model.
It was leaders of the Protestant Reformation that thought nudity itself was sinful as a temptation for sexual behavior. Renaissance nude art was destroyed, or genitals were covered.
Modern Europe
The cultural division between northern and southern Europe can be traced to the sauna. Various methods of cleaning the body by wet or dry heat (causing sweating) are found worldwide. In Finland, almost everyone has access to a sauna. Sharing a sauna with others of all sexes and ages widens the definition of private nudity. Communal bathing breaks the connection between nudity and sexual activity, which is assumed by other cultures. Instead, modesty is in behavior, such as not calling attention to one's own body, and not staring at others.
In the United Kingdom, nudity may be allowed if there is no sexual display intended to cause alarm to the viewer, or create a public disturbance.
Southern Europe views nudity differently than the north. Catholic attitudes did not eliminate classical Greek and Roman history. Mediterranean beaches were the first to adopt the bikini, and then topless fashion. Bathing suits for men are also minimal. Nude beaches also followed, but with a different attitude than the north. Sexuality is less suppressed, part of the enjoyment of being naked. Clothing optional recreation is less widespread than in Northern Europe.
In modern European art, the nude became a symbol that could be used to express all parts of the human condition. The images of nude women that had been created for hundreds of years by male artists are seen by many feminists as degrading to women.
 North America 
Nudity in Canada
Officially, public nudity is disorderly conduct without a "lawful excuse". However, there is another law that a charge of nudity can only be made with the approval of the attorney general. The result is nudity by itself is rarely charged, only when there is another violation involved. There is also the context; nudity at a festival for example is not the same as in ordinary conditions. A woman's right to be top-free as men do has been established in Ontario and British Columbia.
Nudity in Mexico
There is one clothing-optional beach in Mexico, Playa Zipolite in Oaxaca.
Nudity in the United States
America has the greatest disapproval of nudity among Western cultures, and resistance to seeing it as non-sexual. German immigrants brought naturism to the US in the 1930s, but it was limited to "nudist camps" and not widely accepted. Finnish immigrants brought the sauna and mixed nudity to some rural areas, but this became gender segregated.
Nudity was more acceptable during the "counter-culture" of the 1960s-70s. Public nudity became part of music events such as the Woodstock Festival and political events such as Vietnam War protests. There were many unofficially clothing-optional places to swim, but few legal as in Europe. In the more conservative 21st century, many swimming places are again banning nudity.
Oceania
Including Australia, New Zealand and all the Pacific islands, Oceania has both European colonial culture and many indigenous peoples. Similar to other tropical climates, clothing was minimal and removed for both work and play. Colonialism changed this, but not always as expected. The Pacific islands were colonized later than Africa and South America, and the people and cultures more romanticized.
For centuries, clothing indigenous people was part of conversion to Christianity. Rarely, traditional clothing is allowed, as on Yap island where the Catholic Church includes in some celebrations women dancing in costumes that do not cover their breasts.
South America
 Indigenous peoples of the Amazon 160 160
  File:Tigi Nukak.jpg
 Nükák woman and her baby
  Woman and her baby, Nükák tribe, Columbia
  File:Zoe01.jpg
 Two women of the Zo'é tribe of Pará State, Brazil
  Two women of the Zo'é tribe, Brazil
  File:Alto orinoco5.jpg
 Yanomami children, Amazonas State, Venezuela
  Yanomami tribe, Amazonas State, Venezuela
The Awá people of the Amazon rainforest were isolated until recently, first contact being at the beginning of the 21st century. Although now wearing Western clothing at some times, men hunting in the jungle are naked except for a decoration of bird feathers tied to the end of their penises.


Renaissance man: The term Renaissance man or polymath is used for a very clever man who is good at many different things. It is named after the Renaissance period of history (from the 14th century to the 16th or 17th century in Europe). Two of the best-known people from this time were Leonardo da Vinci and Michelangelo. Leonardo da Vinci was a famous painter but was also a scientist, philosopher, engineer, and mathematician. Michelangelo was an extraordinary sculptor, painter, architect, and poet. They are known as two of the highest examples of Renaissance men.
However, the term "Renaissance man" is also often used for extraordinary people not from the Renaissance period. It can be used for anyone who is very clever at many different things, no matter when the person lived. Albert Schweitzer was a 20th-century "Renaissance man" who was a theologian, musician, philosopher and doctor. Benjamin Franklin was an 18th-century "Renaissance man" who was an author, printer, politician, scientist, inventor, and soldier.
 Renaissance period 
it Uomo Universale (Italian: "Universal Man") was the original concept of the Renaissance man abd was an ideal of the Italian Renaissance. One example is the saying by Leone Battista Alberti that "a man can do all things if he will." Many Renaissance men from this time are still famous today:
 Leonardo da Vinci (1452–1519) Italian painter, sculptor, engineer, astronomer, anatomist, biologist, geologist, physicist, architect, musician, philosopher, and humanist.
 Michelangelo (March 6, 1475 – February 18, 1564) was an Italian Renaissance painter, sculptor, architect, poet, engineer, and theologian.
 Niccolò Machiavelli (1469–1527) was a Florentine statesman, philosopher, poet, author, playwright, songwriter, classicist, military scientist, political thinker, and historian.
 Leone Battista Alberti (1404–1472) was an Italian author, artist, architect, poet, priest, linguist, philosopher, and cryptographer.
 Galileo Galilei (1564–1642) was an Italian scientist, mathematician, astronomer, physicist, and philosopher.
 Other polymaths 
 Ancient history 
 Aristotle (Greek: Ἀριστοτέλης, Aristotle) (384 BC – 322 BC) was a Greek philosopher who studied and wrote about many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, politics, government, ethics, biology and zoology.
 Archimedes (Greek: Ἀρχιμήδης; c. 287 BC – c. 212 BC) was a Greek mathematician, physicist, engineer, inventor, and astronomer.
 Medieval history 
 Abū Alī ibn Sīnā (Avicenna) (980–1037) was a Persian physician, pharmacologist, philosopher, mathematician, astronomer, chemist, Hanafi jurist and theologian, scientist, statesman and soldier.
 Ibn Rushd (Averroes) (1126–1198) was an Andalusian Arab philosopher, physician, jurist, astronomer, mathematician, and theologian.
 Roger Bacon, O.F.M. (c. 1214–1294), also known as Doctor Mirabilis (Latin: "wonderful teacher"), was an English Franciscan friar who was a philosopher, theologian and scientist. He was one of the first people to perform scientific experiments in a modern manner.
 Modern history 
 Johann Wolfgang von Goethe (1749–1832) was a German writer, poet, critic, playwright, and novelist.
 Robert Hooke (1635–1703) was an English scientist, mathematician, natural philosopher, and architect.
 Isaac Newton (1643–1727) was an English physicist, mathematician, astronomer, theologian, natural philosopher, and alchemist. His development of calculus and his three laws of motion were landmarks in applied mathematics.
 Gottfried Leibniz (1646–1716) was a German philosopher, theologian, physicist, mathematician, historian, librarian, and inventor.
 Mikhail Lomonosov (1711–1765) was a Russian poet, educator, artist, physicist, chemist, and educator.
 Thomas Jefferson (1743–1826). American president who was a horticulturist, architect, archaeologist, and inventor and the founder of a university.
 Rabindranath Tagore (7 May 1861 – 7 August 1941) was a Bengali poet, artist, playwright, novelist, educator, social reformer, nationalist, business-manager, and composer.
 Albert Einstein (14 March 1879 – 15 April 1955) was a German-American physicist, mathematician, cosmologist, professor, refrigeration engineer (patent), patent analyst, essayist, activist, pianist, and recital violinist.
 G. Spencer-Brown (2 April1923 -25 August 2016)) was an English mathematician and writer of Laws of Form.
References and notes


American Civil War: April 2020
The American Civil War (1861–1865) was a civil war in the United States of America. It was fought when 11 Southern states left the United States and formed the Confederate States of America (also called the Confederacy). The US government and the states that remained loyal to it were called the Union.
The main cause of the war was slavery, which was allowed in the South, including all 11 Confederate States. Slavery was illegal in most of the North. The Confederate States tried to leave the Union after Abraham Lincoln, who disliked slavery, was elected US president. The Union believed that it was illegal for the states to break away. There were five states that allowed slavery which stayed in the Union.
The war began on April 12, 1861, when Confederate forces attacked Fort Sumter, a fort in South Carolina that was held by Union soldiers. The war lasted four years and caused much damage in the South. Most battles were in northern states until 1862 and in southern states after 1862.
After four years of fighting, the Union won the war, and soon, slavery was made illegal everywhere in the United States of America.
 Background 
When the United States of America was founded in 1776, most states allowed slavery. However, over the next 84 years, the Northern states saw that slavery was a bad thing and banned it. The Southern states kept slavery legal. Slaves from Africa grew tobacco, cotton and other cash crops in those states. It was very different in the North, where the Industrial Revolution led to more people working in factories instead of on farms.
The United States became divided into slave and free states. By 1860, those groups were angry at each other. Few people wanted to end slavery in the South and so Americans argued on whether slavery should be allowed to spread to the territories and new states in the west. In the late 1850s, there was fighting in Kansas over whether the territory should allow slavery.
Abraham Lincoln from the Republican Party won the 1860 United States presidential election. He then did not want to ban slavery in the states. Like nearly everyone else, he believed that the US Constitution did not allow the federal government to ban slavery (the amendment to ban slavery was passed later, in 1865). He also thought that banning it suddenly would anger the South.
Instead, Lincoln and his Republican Party thought that slavery should be banned in US territories. They thought that slavery would die out if it could not go to new places.
Lincoln became president on March 4, 1861. In the four months between the election and the day that Lincoln became president, seven Southern states declared their independence from the Union. The outgoing US president, James Buchanan, said that was against the law but he could do nothing to stop them.
The Republican Party treated secession as a rebellion. No country in the world ever recognized the Confederacy as a separate nation. That was because of diplomacy on the part of the Union, anti-slavery feelings in Europe and the northern blockade of southern ports, and of war against the United States.
The first seven states to join the Confederacy were South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas. Four others joined after the fighting began: Virginia, Arkansas, Tennessee, and North Carolina. The Confederacy claimed Kentucky and Missouri belonged to them, but they never joined the Confederacy. Kentucky, Missouri, and Maryland were slave states that tried to avoid taking sides. Delaware supported the Union although it was a slave state. Also, the western counties of Virginia chose to remain in the Union and created a new state, West Virginia.
 Fighting begins 
Fighting started when the Confederates shot and threw bombs at Fort Sumter, a Union Army fort in South Carolina. Lincoln then asked the Union states to bring soldiers to fight the Confederates.
The Confederates said that all forts and other federal buildings in the South belonged to them. On April 12, 1861, Confederate forces attacked the fort and forced the Union soldiers in it to surrender. Lincoln then asked every Union state for volunteers to join the Union Army. Four more southern slave states joined the Confederates, rather than supply forces to fight against them.
The US Navy stopped other ships from going in or out of southern ports. That stopped the Confederacy from selling its cotton and other goods and also made it harder for the South to buy weapons and military supplies.
The war
The American Civil War was fought in three important land areas, or "theaters." The Eastern Theater was the land east of the Appalachian Mountains. The Western Theater included everything between the Appalachian Mountains and the Mississippi River and along the river. The Trans-Mississippi Theater included territory west of the Mississippi River.
Both the United States and the Confederacy had their capital cities in the Eastern Theater. Washington, DC, had been the US capital since 1800. When the South seceded, its first capital was Montgomery, Alabama, but it moved the capital to Richmond, Virginia. Richmond and Washington DC are only about 90 miles (145 km) apart.
One of the first battles of the war was fought in Virginia. The Union tried to march to Richmond, but the Confederates stopped them at the First Battle of Bull Run, on July 21, 1861. The Union Army of the Potomac then tried to capture Richmond in the Peninsula Campaign during the spring of 1862, but Robert E. Lee became leader of the Army of Northern Virginia and defeated the Union Army. He then won the Second Battle of Bull Run in August 1862. Lee tried to win the war by invading Maryland, but he lost the Battle of Antietam and retreated to Virginia. The Eastern Theater was the hardest fight for the Union, as they did not get far in Virginia until 1864. They did much better in other areas.
There was much fighting between ships in the war, but the Union had a stronger and bigger navy. Lincoln put the Confederates under a blockade and so the Union Navy would not let any ships into or out of southern ports. The Confederates used ships called blockade runners to bring things from Europe like weapons. The navies of each side also fought on the rivers. The ships included ironclads, which were protected by iron on their sides, and cottonclads, which used cotton along their sides. During the Battle of Hampton Roads, the Confederate ironclad Virginia fought against the Union ironclad Monitor. It was the first time in world history that two ironclads fought each other.
In the Western Theater, much of the fighting happened along the Mississippi River. Ulysses S. Grant was an important Union general in the West. The Confederates tried to send their soldiers into the state of Kentucky in the summer of 1861. In the early months of 1862, the Union Army made the Confederates retreat from Kentucky and from western Tennessee. They tried to recapture western Tennessee by attacking Grant's army at the Battle of Shiloh, but Grant won the battle. The Confederates then tried to send their soldiers into eastern Kentucky in the fall of 1862 but lost the Battle of Perryville and then left Kentucky. Over the next year, the Union took control of the rest of Tennessee.
The North won control of almost all of the Mississippi River by capturing the cities along the river in the fall of 1862 and the spring of 1863. However, the Confederacy still held Vicksburg, an important city and fort. If they held, the Confederates could move soldiers and supplies from one side of the river to the other. Grant started the Siege of Vicksburg during the month of May 1863. The siege continued until July 4, 1863, when the Confederates there surrendered to Grant. That was one of the turning points in the war by dividing the Confederacy into two parts.
There were also battles west of the Mississippi River Valley in the Trans-Mississippi Theater. For example, two important battles were the Battle of Wilson's Creek and the Battle of Pea Ridge. The Confederates tried to invade New Mexico in February and March 1862 but they were defeated at the Battle of Glorieta Pass. After the Union captured Vicksburg, the area became separated from the rest of the Confederate States. Other battles happened in the area after the capture of Vicksburg.
During the Siege of Vicksburg in the west, another turning point came in the east. After winning some battles, Lee decided to invade the North again. Lee and his Army of Northern Virginia went into Pennsylvania. The Confederate Army met the Union Army near Gettysburg, Pennsylvania and fought the Battle of Gettysburg, which lasted from July 1 to 3, 1863. More soldiers died at Gettysburg than in any other Civil War battle, which the Union won. Lee and his troops were pushed back into the South and could no longer invade the North.
From Vicksburg, Grant led the army to finish taking control of Tennessee in the Chattanooga campaign. Lincoln then decided that Grant was his best general and put Grant in control of all Union armies. Abraham Lincoln also made William Tecumseh Sherman the general in charge leading the Union troops from Tennessee to Georgia. Grant led many attacks on Lee's army in Virginia. The battles were made up the Overland Campaign.
The Union had more success when Sherman marched into Georgia in May 1864, into the middle of the Confederate States. In September, he captured Atlanta, an important city. Sherman then led a "march to the sea" and captured Savannah. He then marched north through South Carolina and North Carolina. Confederate General Joseph E. Johnston attacked Sherman at the Battle of Bentonville. Sherman won the battle. Even in the 20th century, Southerners remember Sherman's march as destroying many homes, farms, and railroads, but his soldiers are blamed for things that they could not have done since they were too far away.
By late 1864, Lee's army was struggling, as they had less soldiers and supplies than Grant's army. Helped by Philip Sheridan, Grant's army slowly started to push into Virginia. At the start of April 1865, they won several battles against Lee's army and captured Richmond. Lee decided that he had too few soldiers to keep on fighting. He surrendered to Grant on April 9, 1865 near Appomattox Court House. Later, many other Confederate armies surrendered as well. The last Confederate general to surrender was Brigadier General Stand Watie, who surrendered on June 23, 1865, in Oklahoma.
After the war ended, Lincoln pardoned all of the Confederate soldiers and so they could not be arrested or punished for fighting against the Union. The South would be allowed to rejoin the United States but only later. Some Confederates did not want to return to the United States and moved to places like Mexico or Brazil.
Why the Union won
Historians have had different ideas about whether the Confederacy could have won the war. Most of them, such as James McPherson, say that it would have been difficult but possible. The Union had far more people, money and industry.McPherson 1988 855Murray Bernstein Knox 1996 235HeidlerHeidlerColes 2002 1207–10 By most estimates, the Union had over 2 million soldiers while the Confederacy had 1 million.
One advantage the Confederacy had was that they only needed to defend their land, whereas the Union could only win if they took full control of the Confederate states.McPherson 1988 771–72 Furthermore, the Union could only fight the war if their people wanted them to keep fighting. Lincoln had opponents in the North (the Copperheads) who wanted the war to end. If the Confederacy had defended itself for long enough, it may have led to more people in the Union turning against the war and supporting the Copperheads. However, Lincoln held on to his support and won the 1864 election.McPherson 1988 771–72
The Union Navy blocked ships from going into the Confederate ports. Although some ships managed to get past, most could not. The Confederacy had big money problems because they could not sell cotton and other goods to other countries.McPherson 1988 382–88 The Confederacy collected less taxes than the Union, so they printed money to pay for the war. This caused inflation (rising prices).
Another factor was that the Confederacy could not get help from outside. They had hoped that Britain and France would support the Confederacy because they wanted to buy their cotton. However, Britain and France did not give them help. There were three reasons for this. Firstly, they thought that slavery was wrong. Secondly, they did not want to become enemies of the United States. Thirdly, they could get cotton from elsewhere.McPherson 1988 382–88
Most historians also think that Abraham Lincoln was a better leader than Jefferson Davis. Don E. Fehrenbacher says that Lincoln's skills helped keep the Border States and ordinary people on his side. Lincoln left his generals alone if they did a good job and fired them if they did not. Davis lacked a clear plan, tried to do too many tasks at once and often chose people to do jobs just because they were his friends. He annoyed his generals and other Confederate politicians. William Cooper says that better leadership helped the Union, but they were already more likely to win.
After the war
Many soldiers on both sides died during the war. Most of the war was fought in the South. Many railroads, farms, houses and other things were destroyed, and most people living there became very poor.
After the war, some of the Union Army's leaders went into politics. Generals like Grant, Hayes, Garfield, Harrison, and McKinley became US presidents. Other veterans were elected to other offices.
 Reconstruction 
The period after the war, called Reconstruction, lasted from the end of the war to 1877. The Union Army stayed in some Southern states and made them occupied territory. 
During Reconstruction, black Americans built schools and other social infrastructure. Some of the schools became the historically black colleges that still exist. After southern states rejoined the Union, most of them made laws that limited what black people could do.
The Southern states were allowed to ask to rejoin the union. When they were accepted, that could send senators and representatives to the US Congress again and make their own state laws. 
The Amnesty Act of 1872 restored the rights to vote and to hold political office for most former members of the Confederacy. Some of them also became politicians.
 New Amendments 
Three important amendments were added on to the US Constitution. The amendments were suggested by the US government. Although not every American supported them, they got enough support to pass.
The Thirteenth Amendment says that slavery is not allowed anywhere in the United States. This completed the work of the Emancipation Proclamation.
The Fourteenth Amendment makes it clear that all people born in the United States are citizens, and all citizens have equal rights.
The Fifteenth Amendment says that people in the United States cannot be kept from voting because of their race.


Mooresville, Indiana: October 2024
Mooresville is a town in Brown Township, Morgan County, Indiana, United States. Located approximately 16 miles southwest of downtown Indianapolis, Mooresville is known for its rich history, community spirit, and small-town charm. As of the 2020 census, the town had a population of approximately 9,300 residents.
History
Mooresville was founded in 1824 by Samuel Moore, a Quaker, who intended to create a community based on his values of simplicity, peace, integrity, community, and equality. The town quickly grew as a center for agriculture and commerce, thanks to the fertile land and strategic location. The Mooresville Friends Academy, established in 1861, played a significant role in the town's educational development.
Throughout the 19th and early 20th centuries, Mooresville became known for its apple orchards and canneries, which were major contributors to the local economy. The arrival of the railroad in the late 1800s further spurred growth and development. The town's historical significance is preserved in several well-maintained buildings and landmarks.
Geography
Mooresville is located in central Indiana and is part of the Indianapolis Metropolitan Area. The town covers an area of 6.34 square miles, featuring a mix of residential, commercial, and agricultural land. It is bordered by the White River to the east and includes several small lakes and parks within its boundaries. The town's landscape is characterized by rolling hills, lush greenery, and scenic waterways.
Demographics
As of the 2020 census, Mooresville had a population of around 9,300 residents. The town's population is diverse, with a mix of families, young professionals, and retirees. The median household income in Mooresville is comparable to state averages, and the town has a relatively high rate of homeownership. The community is known for its friendly and welcoming atmosphere.
Economy
The economy of Mooresville is primarily driven by small businesses, agriculture, and retail. The town has seen growth in recent years with the development of new housing and commercial projects. Major employers in the area include the Mooresville Consolidated School Corporation, local healthcare providers, and various retail stores. The town's proximity to Indianapolis also provides residents with additional employment opportunities in the city.
Mooresville has a growing tourism sector, with visitors drawn to its historic downtown area, local festivals, and outdoor recreational opportunities. The town's economic development efforts focus on supporting local businesses, attracting new investments, and enhancing the quality of life for residents.
Education
Mooresville is served by the Mooresville Consolidated School Corporation, which includes several elementary schools, one middle school, and Mooresville High School. The town is also home to the historic Mooresville Friends Academy, which has been a cornerstone of education in the community since its founding in the 19th century. The academy is known for its strong academic programs and commitment to Quaker values.
In addition to public education, there are several private and parochial schools in the area. Higher education opportunities are available in nearby Indianapolis, which is home to several colleges and universities, including Indiana University–Purdue University Indianapolis (IUPUI) and Butler University.
Culture and community
Mooresville hosts several annual events and festivals that celebrate its history and community spirit. The Old Settlers Festival, held every summer, is one of the town's most popular events, featuring parades, live music, food vendors, and carnival rides. The town also celebrates Independence Day with a large fireworks display and community gathering.
The Mooresville Park and Recreation District manages several parks and recreational facilities, providing residents with opportunities for outdoor activities and sports. Pioneer Park, the largest park in the town, offers walking trails, sports fields, playgrounds, and a swimming pool. The town also has a community center that hosts various programs and activities for all ages.
Notable people
 Paul Hadley: Designer of the Indiana state flag, was a resident of Mooresville.
 Karl Malden: Academy Award-winning actor, spent part of his childhood in Mooresville.
 John Wooden: Renowned basketball coach, began his coaching career at Mooresville High School.
Government
Mooresville operates under a town council form of government. The town council is responsible for enacting local ordinances, approving budgets, and overseeing municipal services. The town also has a clerk-treasurer who manages financial affairs and a town manager who oversees day-to-day operations. The local government is committed to maintaining the town's infrastructure, ensuring public safety, and promoting economic development.
Infrastructure
Mooresville is well-connected by a network of roads and highways, including State Road 67, which provides direct access to Indianapolis. Public transportation options are limited, but the town is served by several regional transit systems. The nearest major airport is Indianapolis International Airport, located about 10 miles northeast of Mooresville. The town also has access to rail services and is within driving distance of several major interstate highways.
Healthcare
Healthcare services in Mooresville are provided by a range of local clinics and medical practices. The town is also within easy reach of several major hospitals and healthcare facilities in Indianapolis, ensuring residents have access to comprehensive medical care. Mooresville's healthcare providers offer a wide range of services, including primary care, specialty care, and emergency medical services.


Republicanism in the United States: Republicanism in the United States is a set of ideas that guides the government and politics. These ideas have shaped the government, and the way people in the United States think about politics, since the American Revolution.
The American Revolution, the Declaration of Independence (1776), the Constitution (1787), and even the Gettysburg Address (1863) were based on ideas from American republicanism.
"Republicanism" comes from the word "republic." However, they are not the same thing. A republic is a type of government (one where the people can choose their leaders). Republicanism is an ideology set of beliefs that people in a republic have about what is most important to them.
Definition
Republicanism in the United States grew out of some very old ideas. It includes ideas from ancient Greece, ancient Rome, the Renaissance, and England.
Some of the most important ideas of republicanism are that:
 Liberty and "unalienable" rights (natural rights) are some of the most important things in a society
 Government should exist to protect these rights
 The people who live in a country, as a whole, should be sovereign (they should be able to choose who leads them and have a say in how their government is run)
 Power must always be given by the people, never inherited (like in a monarchy)
 People must all play a role in their government by doing things like voting
 Political corruption is terrible and has no place in a republic
Republicanism is different than other forms of democracy. In a "pure" democracy, the majority rules. If a majority of the people voted to take rights away from a certain group, that is what would happen. Alexis de Tocqueville, a famous French political thinker, called this the "tyranny of the majority." He meant that a pure democracy could still turn into an unfair, unequal, corrupt society if the majority of the people decided to take away others' rights.
However, republicanism says that people have "unalienable" rights that cannot be voted away. Republican governments are different than "pure" democracies, because they include protections to make sure people's rights are not taken away. In a true republican government, one group - even if it is a majority - cannot take another group's unalienable rights away.
The American Revolution
American republicanism was created and first practiced by the Founding Fathers in the 18th century. For them, "republicanism represented more than a particular form of government. It was a way of life, a core ideology, an uncompromising commitment to liberty, and a total rejection of aristocracy." Republicanism shaped what the Founders thought and did during the American Revolution, and after.
Creating American republicanism
The leaders of colonial America in the 1760s and 1770s read history carefully. Their goal was to compare governments and how well different types of governments worked. They were especially interested in the history of liberty in England. They modeled American republicanism partly after the English "Country Party." This was a political party which opposed the Court Party, which held power in England.
The Country Party was based on ancient Greek and Roman republicanism. The Party criticized the corruption in the "Court" Party, which focused mostly on the King's court in London. It did not focus on the needs of regular people in England, or on areas outside of the capital city.
By reading history, The Founders came up with a set of political ideas that they called "republicanism." By 1775, these ideas were common in colonial America. One historian writes: "Republicanism was the distinctive political [way of thinking] of the entire Revolutionary generation."
Another historian explains that believers of American republicanism saw government as a threat. He writes that colonists felt constantly "threatened by corruption." Government, to them, was "the [biggest] source of corruption and operat[ed] through such means as patronage, faction, standing armies ( [instead of] the ideal of the militia); [and] established churches" which people would have to belong to.
Cause of Revolution
By the 1770s, most Americans were dedicated to republican values and to their property rights. This helped cause the American Revolution. More and more, Americans saw Britain as corrupt; hostile; and a threat to republicanism, freedom, and property rights. Many people thought that the greatest threat to liberty was corruption not just in London, but at home too. They thought corruption went along with inherited aristocracy, which they hated.
During the Revolution, many Christians connected republicanism with their religion. When the Revolution started, there was a major change in thinking that "convinced Americans ... that God was raising up America for some special purpose," according to one historian. This made the Revolutionists believe that they had a moral and religious duty to get rid of the corruption in the monarchy.
Another historian, Gordon Wood, writes that republicanism led to American Exceptionalism: "Our beliefs in liberty, equality, constitutionalism, and the well-being of ordinary people came out of the Revolutionary era. So too did our idea that we Americans are a special people with a special destiny to lead the world toward liberty and democracy."
In his Discourse of 1759, Revolutionist Jonathan Mayhew argued that people should only obey their governments if they "actually perform the duty of rulers by exercising a reasonable and [fair] authority for the good of human society." Many American colonists were convinced that British rulers were not using their power "for the good of human society." This made them want to form a new government which would be based on republicanism. They thought a republican government would protect not threaten freedom and democracy.
Founding Fathers
The "Founding Fathers" were strong supporters of republican values, especially Samuel Adams, Patrick Henry, George Washington, Thomas Paine, Benjamin Franklin, John Adams, Thomas Jefferson, James Madison, and Alexander Hamilton.
For example, Thomas Jefferson once wrote that a government that had the most possible participation by "its citizens in mass" (all the people together) was the safest kind. He said a republic is:
The Founding Fathers often talked about what "republicanism" meant. In 1787, John Adams defined it as "a government, in which all men, rich and poor, magistrates and subjects, officers and people, masters and servants, the first citizen and the last, are equally subject to the laws."
Other ideas
Some other ideas also affected the Founding Fathers. For example, in the 1600s, John Locke, an English philosopher, had created the idea of the "social contract." This idea said that people agree to obey governments, and in return, those governments agree to protect the people and their rights. This is like a contract made between the people and the government. If the government breaks this contract, and does not protect the people's rights, then the people have the right to overthrow their leaders. This idea was important to the Revolutionists.
When they were writing state and national constitutions, the Americans used ideas from Montesquieu, an 18th-century French political thinker. Montesquieu wrote about how the perfect British constitution would be "balanced." The idea of a balance of power (also called "checks and balances") is a very important part of the Constitution. It is one of the strategies the Founders used to make sure their government would be republican and protect the people from government corruption.
The Constitution
The Founding Fathers wanted republicanism because its ideas guaranteed liberty, with limited powers checking and balancing each other. However, they also wanted change to happen slowly. They worried that in a democracy, the majority of voters could vote away rights and freedoms. They were most worried about poor Americans (who made up most of the United States) turning against the rich. They worried that democracy could turn into "mob rule."
To guard against this, the Founders wrote many protections into the Constitution. For example:
 They made sure the Constitution can only be changed by a "supermajority": two-thirds of the United States Congress and three-fourths of the state legislaturesThere are a few other ways that the Constitution can be changed, but they are not common. They also require supermajorities. For more information, see the page on Article Five of the United States Constitution. 
 They set up a court system that could help protect people's rights if the majority of Americans decided to take a group's rights away 
 They created an Electoral College, where a small number of elite people would select the President
 Soon, political parties controlled elections more than the Electoral College did
 They gave the states control of the United States Senate by letting state legislatures choose Senators (this changed over time)
 They set up a House of Representatives to represent the people
Most adult white males were able to vote. In 1776, most states required people to own property to be able to vote. However, at that time, America was 90% rural, and most people owned farms. As cities grew bigger and people started doing work in the cities, most states dropped the property requirement. By 1850, this requirement was gone in every state.
Republican motherhood
Under the new government after the Revolution, "republican motherhood" became an ideal. Abigail Adams and Mercy Otis Warren were held up as the perfect "republican mothers." This idea said that a republican mother's first duty was to teach her children republican values. Her second job was to live simply and avoid luxury, which the Founders linked with corruption.
Democracy
Many of the Founders did not think "democracy" was a good idea. Their idea of "democracy" was the "pure democracy" that de Tocqueville had described. They worried often about the problem of 'tyranny of the majority' that de Tocqueville had warned about. They wrote many protections into the Constitution to prevent this from happening. As historians Richard Ellis and Michael Nelson write: "The principles of republican government embedded in the Constitution represent an effort by the framers to [make sure] that the inalienable rights of life, liberty, and the pursuit of happiness would not be [destroyed] by majorities." Thomas Jefferson warned that "an elect[ed] despotism is not the government we fought for."
James Madison, in particular, worried about this, and wrote about it in The Federalist Papers. The Federalist Papers talk about democracy as being dangerous, because it allows a majority to take away the rights of a smaller group. However, Madison thought that as more people came to the United States, the country would get more diverse, and it would be harder to form a majority big enough to do this. In Federalist No. 10, Madison also argued that a strong federal government would help protect republicanism. The United States' first constitution, the Articles of Confederation, gave most power to the states and had a very weak federal government that could not get anything done. In Federalist No. 10, Madison argued that a small but powerful group might be able to take control of a small area, like a state. However, it would be much harder to take over an entire country. The bigger the country, he argued, the safer republicanism would be.
As late as 1800, the word "democrat" still had a very bad meaning to most Americans. It was mostly used to attack an opponent of the Federalist party. In 1798, George Washington complained that a "Democrat ... will leave nothing unattempted to overturn the Government of this Country." This changed over the next few decades.
Property rights
United States Supreme Court Justice Joseph Story (1779–1845) made the protection of property rights by the courts a major part of American republicanism. James Madison appointed Story to the Court in 1811. Story and Chief Justice John Marshall made the Court a protector of the rights of property against runaway democracy. Story believed that "the right of the citizens to the free enjoyment of their property" (if they got it legally) was "a great and fundamental principle of a republican government." Historians agree that Story—as much or more than Marshall or anyone else—reshaped American law in a conservative direction that protected property rights.
Military service
Republicanism saw military service as one of a citizen's most important duties. John Randolph, a Congressman from Virginia, once said: "When citizen and soldier shall be synonymous terms, then you will be safe."
However, at this time, the word "army" meant "foreign mercenaries." After the Revolutionary War, Americans did not trust mercenaries. Instead, they came up with the idea of a national army, made of citizens. They changed their definition of military service from a choice of careers to a civic duty something every good republican should do. Before the Civil War, people saw military service as an important show of patriotism, and a necessary part of citizenship. To soldiers, military service was something they chose to do, something they had a say in, and it showed that they were good citizens.
Legal terms
Republic
The term republic is not used in the Declaration of Independence. However, it does appear in Article Four of the Constitution, which "guarantee[s] to every State in this Union a Republican form of Government."
The United States Supreme Court has created a basic definition of what a "republic" is. In United States v. Cruikshank (1875), the court ruled that the "equal rights of citizens" were inherent to the idea of a republic. Later, the Court's decision from In re Duncan (1891) ruled that the "right of the people to choose their government" is also part of the definition of a republic.
Democracy
Over time, most Americans changed their opinion about the word "democracy." By the 1830s, most Americans saw democracy as a great thing, and members of the new Democratic Party proudly called themselves "Democrats."
After 1800, the limitations on democracy (like rules that limited who could vote) were removed one by one:
 By the 1820s, most states had ended rules saying that people had to own property in order to vote. By 1850, all of them had. 
 In 1870, the Fifteenth Amendment gave all men in the United States the right to vote, including ex-slaves. 
 In 1913, the Seventeenth Amendment allowed the people to elect their own United States Senators (before this, the state legislatures had chosen U.S. Senators). 
 The Nineteenth Amendment, passed in 1920, gave women the right to vote. 
 The Voting Rights Act of 1965 made the last rules that kept black people from voting illegal. 
 Finally, in 1971, the Twenty-sixth Amendment gave adults ages 18 to 20 the right to vote.


Indian independence movement: March 2021
The Indian independence movement was a movement from 1857 until 15 August 1947, when India and Pakistan got its independence from the British Raj.
 European Rule 
Vasco da Gama of Portugal had discovered a sea route to India. He had reached Calicut, Kerala in 1498. After this, many Europeans started coming to India for trading. They made their offices and forts in various parts of India. The British East India Company became the major force in India. The company's troops led by Robert Clive defeated the rulers of Bengal in 1757. This battle became famous as the Battle of Plassey. That was the beginning of British rule, known as the British Raj, in India. In 1764, the Battle of Buxar was won by the English forces. After this, the British got control over Bengal, Bihar and Orissa.
The Parliament of the United Kingdom passed many laws to help the British East India Company. The Regulating Act of 1773, the India Act of 1784, and the Charter Act of 1813 were designed to help trade with India.
Before the First War of Independence (1857), Indians in different parts of India had revolted against the British. Many such of the revolts and armed struggles had taken place in this Some examples include:
 Revolts by many local rulers of Tamil people in southern India like Dheeran Chinnamalai, Veerapandiya Kattabomman ...etc.
 In 1825 in Karnataka kittur Chennamma rejected Doctrine of Lapsi and refused British rulers any royalty. She defeated British in the war. Kittur was defeated by British army in the second war. Her lieutenant Sangolli Rayanna continued the revolt until he was killed.
 A revolt in 1787 took place in Goa against the rule of Portugal. The histo call this revolt as the Conspiracy of the Pintos.
 A rebellion by tribes of Jharkhand in India. Historians call this Santhal Rebellion
 Rebellion under the leadership of Titumir in Bengal.
 Revolt of 1857 
India's First War of Independence (by this name later a book was published by V.D Savarkar) was a revolt of Indian soldiers and people (rulers and peasants) against British rule. Historians had used the terms like the Indian Mutiny or the Sepoy Mutiny to describe this event. The rebellion by Indian troops of the British Raj started in May 1857 and continued until December 1858. Many reasons had combined to result in this rebellion.
The British rulers continued to forcibly take regions ruled by Indians and made these regions part of the British Raj. They did not give any respect to old royal houses of India like the Mughals and the Peshwa. They also made the Indian soldiers of their army use a special type of cartridge (immediate cause of the rebel). The soldiers had to open the cartridges with their teeth before loading them into their guns. The cartridges supposedly used cow and pig fat. For Hindus the cow is a sacred animal and they do not eat beef. Similarly, Muslims do not eat pork. Thus, the use of these cartridges made soldiers of both the religions turn against the British. Although the British tried to replace the cartridges, the feelings against them stayed.
Rebellion broke out when a soldier called Mangal Pandey attacked a British sergeant and wounded an adjutant. General Hearsey ordered another Indian soldier to arrest Mangal Pandey but he refused. Later the British arrested Mangal Pandey and the other Indian soldier. The British killed both by hanging them.
At the beginning the British were slow to respond. Then they took very quick action with heavy forces. They brought their regiments from the Crimean War to India. They also redirected many regiments that were going to China from India. The British forces reached Delhi, and they surrounded the city from 1st July 1857 until 31st August 1857. Street-to-street fights broke out between the British troops and the Indians. Ultimately, they took control of Delhi. The massacre at Kanpur (July 1857) and the siege of Lucknow (June to November 1857) were also important. The last important battle was at Gwalior in June 1858 in which the Rani of Jhansi was killed. With this, the British had practically suppressed the rebellion. However, some guerrilla fighting in many places continued until early in 1859 and Tantia Tope was captured and executed until April 1859.
 The Results 
India's First War of Independence was a major event in the history of modern India. The Parliament of the United Kingdom withdrew the right of the British East India Company to rule India in November 1858. The United Kingdom started ruling India directly through its representative called the Viceroy of India(earlier governor-general of India). It made India a part of the British Empire. They promised "the Princes, Chiefs, and People of India," equal treatment under the British law.
The British sent Bahadur Shah II, the last Mughal Emperor, out of India, and kept him in Rangoon (now called Yangon in Burmese), Burma where he died in 1862. The Mughal dynasty, which had ruled India for about four hundred years, ended with his death.
The British also took many steps to employ Indian higher castes and rulers into the government. They stopped taking the lands of the remaining princes and rulers of India. They stopped interference in religious matters. They started employing Indians in the civil services but at lower levels. They increased the number of British soldiers, and allowed only British soldiers to handle artillery.
 Organised movements 
The period following India's First War of Independence was an important period in the Indian independence movement. Many leaders emerged at the national and provincial levels, and the Indians became more aware of their rights. Social movements also helped in shaping people's outlook, tried for social changes, and tried to remove bad social practices and evils like illiteracy and caste system. During this period, many social and religious leaders worked to inspire the Indian society. They included men like Swami Vivekananda, Ramakrishna , Sri Aurobindo, Subramanya Bharathy, Bankim Chandra Chatterjee, Sir Syed Ahmed Khan, Rabindranath Tagore and Dadabhai Naoroji. They spread the message of self-confidence, removing of social evils, and making India free from domination of foreign power. Lokmanya Tilak was one such leader who was not very modest in his views. The British arrested him. In the court he declared: "Swaraj (independence) is my birthright". This concept of Swaraj later became a main policy and philosophy of India's independence movement in the following decades until India became independent. 
In 1885, at the suggestion of Allan Octavian Hume, a retired British civil servant, seventy-three Indian delegates met in Bombay. They founded the Indian National Congress. The delegates represented educated Indians in professions such as law, teaching, and journalism. A few years before, Dadabhai Naoroji had already formed the East India Association. It merged with the Indian National Congress to form a bigger party. 
To begin with, the Indian National Congress was not a very active political party. It met annually and gave some suggestions to the rulers of the British Raj. The suggestions generally related to civil rights and opportunities for Indians in the government jobs. Despite its claim to represent all Indians, it represented only the educated and higher class of the society. But, it failed to attract all Muslims. Many Muslims had become distrustful of Hindu reformers who raised their voice against matters like religious conversion and killing of cows for their meat. For Hindus, the cow is a sacred animal not to be killed. Sir Syed Ahmed Khan launched a separate movement for Muslims, and founded in 1875 a college in Aligarh, Uttar Pradesh state, India. Later, this college became Aligarh University in 1921. The objective of the college was to give modern education to India's Muslims. By 1900, the Indian National Congress had become a national party, but did not represent all groups of Indian society, particularly the Muslims.
Partition of Bengal
In 1905, Lord Curzon (George Nathaniel Curzon, 1st Marquess Curzon of Kedleston), the Viceroy and Governor-General (1899-1905) of India divided Bengal province into two provinces: Eastern Bengal & Assam, with its capital at Dhaka, and West Bengal, with its capital at Calcutta (Kolkata). At that time Calcutta was the capital city of the British Raj. The people became very angry at that partition (division), and created the phrase "divide and rule" for the policy followed by the British Empire. The leading intellectual figures of India at that time expressed their unhappiness at this partition. For example, Rabindranath Tagore, the most famous Indian poet (originally from Bengal) composed a poem against this partition.
 World War I 
During the First World War, Indians gave support to the United Kingdom. About 1.3 million Indian soldiers went to many parts of Europe, Africa, and the Middle East to fight. Many Indians, including the princes and rich people of India, contributed money and materials to the war funds of the United Kingdom. However, many Indian soldiers died in foreign lands. In India, flu called Spanish flu spread like an epidemic killing many people. The tax rates increased in India, and prices also increased. The Indians became restless.
In August 1917, Edwin Samuel Montagu, the Secretary of State for India, announced in the British Parliament about many steps to give more rights to Indians. A new law named the Government of India Act of 1919 gave many rights to the Indians in the provincial government. These rights related to farming, local government, health, education, and public works. The British administrators kept matters like taxation, finance, and law and order under their control.
 The Rowlatt Act 
In 1919 the British made a new law named the Rowlatt Act. Under this law, the government got many powers, including the ability to arrest people and keep them in prisons without a trial. They also obtained the power to stop newspapers from reporting and printing news. The people called this act the Black Act. Indians protested against this law in many places.
The positive impact of reform was seriously undermined in 1919 by the Rowlatt Act, named after the recommendations made the previous year to the Imperial Legislative Council by the Rowlatt Commission, which had been appointed to investigate "seditious conspiracy." The Rowlatt Act, also known as the Black Act, vested the Viceroy's government with extraordinary powers to quell sedition by silencing the press, detaining political activists without trial, and arresting any individuals suspected of sedition or treason without a warrant. In protest, a nationwide cessation of work (hartal) was called, marking the beginning of widespread, although not nationwide, popular discontent.
The agitation reached a peak in Amritsar (Punjab, India). In Amritsar, on 13th April 1919, about 10,000 Indians had assembled at Jallianwala Bagh. They had no idea of the law that they couldn't gather. The British military commander, Brigadier-General Reginald Dyer ordered his troops to fire at the civilians without any warning. The troops fired 1,650 times. Some historians estimate that the troops killed 379 and injured about 1,137 people. This incident came to be known as the Jallianwala Bagh massacre. With this killing of innocent people, the British lost the trust of the Indian people.
Congress forced Britishers to investigate massacre of jallianwala later, a tehkikat committee was made by congress.
 Gandhi's way 
Mohandas Karamchand Gandhi (also known as Mahatma Gandhi) had received his education at London. He was a barrister (lawyer). In 1893, he went to South Africa. After Gandhi was thrown off a train because he was a colored person sitting in a first-class seat, he took that emotion and used it to begin to fight the injustices that many people of color faced at the time. He became successful and the government of South Africa removed most of such rules and restrictions. Gandhi led the Salt March, an act of protest.
When Gandhi returned to India in 1915, few people knew him. Under the leadership of Gandhi, Indians began to use a different method to get freedom over the next few years.
 Civil disobedience 
In December 1929, the Indian National Congress Party agreed to start a movement for complete independence from British rule. The Party decided to start a movement named to disobey the British rule. It became the civil disobedience movement. They decided to observe 26th January 1930 as the complete Independence Day (this is the reason why India celebrate republic day on 26 January). Many other political parties and revolutionaries came together to support this movement.
Gandhi started this movement, leading 72 people on a 400 kilometer route from Ahmedabad to Dandi (both in the Indian state of Gujarat), on the coast of the Arabian Sea. There they made salt from the seawater and broke a law of British India prohibiting making salt without paying taxes, so this event is referred to as the Salt March. Thus the civil disobedience movement began, and it soon spread throughout India. Indians started to break unfair laws in a peaceful manner in protest against the British rule.The effect of civil disobedience movement in Kerala was at Payannur and Beypore.
 Revolutionary activities 
Many Indians did not believe in such peaceful protests, claiming that the British would not give independence to Indians so easily. They believed in armed struggle was necessary to oust the British from India. In some way, this had continued for years after the partition of Bengal in 1905. Many revolutionaries and leaders emerged from time to time. Bhagat Singh was one of them.
 The elections 
The rulers of the British Raj made a new law to govern India, named the Government of India Act 1935. This law aimed at constitutional process to govern India. It had three major aims: to establish a federal system with many provinces, to give self-ruling position (autonomy) to the provinces, and to give the Muslim minority protection through giving them some separate electorates. In such separate electorates only Muslims could stand for elections. In February 1937, elections took place for the provincial assemblies. The members of the Indian National Congress won in five provinces, and held upper position in two more provinces. The Muslim League's performance in the election was not good.
 The Indian move to freedom 
During the Second World War, the rulers of the British Raj declared India to be a party to the war. They did not discuss the matter with Indians and their leaders. The Indians and their leaders became divided over this matter. Some supported the British, while many did not. British rulers of India wanted the Indians to fight and die in the name of freedom, yet they had denied this freedom to India and the Indians for more than a hundred years. This created a lot of dissatisfaction among Indians, and two big movements for India's independence took shape. The first was the Indian National Army of Subhas Chandra Bose. The second was Quit India Movement of Mohandas Gandhi.
 The Indian National Army 
Subhas Chandra Bose and many leaders did not like the British decision to drag India into the Second World War. He had twice (in 1937 and 1939) become president of the Indian National Congress Party, the leading Indian political party of that time. However, he and many other leaders of the Indian National Congress Party differed on many matters. He resigned and formed a new party named All India Forward Bloc. The British government of India put him under house arrest, but he escaped in 1941. He reached Germany and secured the support of Germany and Japan to fight the British in India. In 1943, he traveled in submarines of Germany and Japan, and reached Japan. He organised the Indian National Army. The INA fought the troops of the British Raj in northeastern India. Despite many difficulties, INA recorded many victories. However, with the surrender of Japan in 1945, INA's operations stopped. Bose died in a plane crash, but circumstances of his death are not clear.
The British government of India put on trial three Indian National Army officers at the Red Fort in Delhi. The British had chosen for this trial one Hindu, one Sikh, and one Muslim of the INA. This made many Indians of all religions very angry. A naval mutiny also broke out in Bombay. Ultimately, the British ruled that these officers were guilty, but they set them free seeing the public anger. When India became independent, the government of India did not allow the former officers and soldiers of the INA to join the armed forces of the independent India. However, the government granted them very good pensions and other facilities. The Indian public also gave them much respect.
Many consider Netaji Subhas Chandra Bose a controversial figure due to his association with the Axis Powers. But, in India, people consider him a patriotic hero of the Indian independence movement.
 Quit India 
On 8th August 1942, the leaders of the Indian National Congress Party met in Bombay (Mumbai). The leaders adopted a policy to force the British out of India. Gandhi's slogan "Do or Die" became a national slogan, and the movement became the Quit India Movement. At the beginning of the Second World War, the Indian National Congress Party had supported the British, but they had demanded freedom for India after the war. The British did not agree to this proposal. On 14th July 1942, the Indian National Congress Party passed a resolution demanding complete independence from the British rule. However, this did not have support of some other political parties.
Gandhi had asked the people to keep the Quit India Movement as a peaceful movement. Many people started the movement in many places of India. But at some places, the movements turned violent. Gandhi refused to eat until the violence stopped. He was successful in ending the violence.
The British action was very quick. They arrested over 100,000 people. They levied fines on many people. They dropped bombs on the people who demonstrated against the British Raj. The troops of the British Raj even beat people with sticks and caned them. The British arrested all the leaders of the Congress Party. Gandhi's wife, Kasturba Gandhi, died during detention, as well as his secretary Mahadev Desai. Gandhi's health had also become very bad. In 1944, the British set him free fearing that Gandhi's death might result in a very large protest by Indians. Gandhi continued to oppose the British, and demanded that all other leaders be set free.
The Second World War had reduced the economic, political, and military strength of the British Empire. They were also aware that after the war Indians would begin a larger movement for independence. The mood of the British people and the British Army had also changed. After the Second World War, most of them were no longer willing to support the British ruling class in India. That position was now clear to the leaders of the United Kingdom. By early 1946, those leaders set free all the political prisoners held in India and opened independence discussions with the Indian National Congress Party. On the 14th of August 1947 Pakistan gained independence and a day later on the 15th of August India gained its independence as well.
 India's independence (1947 to 1950) 
On midnight of 14th and 15th August 1947, Britain handed India and Pakistan its formal political Independence. A short time after that, Gandhi, who was aging and ill, died from a bullet fired by a Hindu extremist named Nathuram Godse. The national leadership was then passed to his chief lieutenant, Jawaharlal Nehru. On 3rd June 1947, the Viceroy Lord Mountbatten announced partition of India into two countries: a Secular India, and an Islamic Pakistan. In this partition, many people died while others were separated from their families. On 26th January 1950, India adopted their constitution, the longest constitution in the world.


Republican Party (United States): GOP
The Republican Party, also known as the Grand Old Party (GOP) is one of the two biggest political parties in the United States. Since the mid-1850's, the party's main opponent has been the Democratic Party. Both political parties have controlled American politics ever since. The party sits at the right-wing of the American political spectrum, with the Democratic Party being positioned to their left. However, there also factions of the Republican Party that are center-right to far-right.
Ideologically, Republicans favor fiscal and social conservatism. It opposes single-payer healthcare, abortion, euthanasia, labor unions, affirmative action, marijuana legalization, gay marriage and a high minimum wage. It advocates for low taxes, limited government, gun rights, free markets, traditional values and free trade. It did, however, hold protectionist opinions during its early days, for example during Theodore Roosevelt’s presidency. It also held anti-free trade opinions during Donald Trump’s presidency.
The symbol of the Republican party is the elephant. This symbol was first used in 1874 in a political cartoon by Thomas Nast. The Republican National Committee, or the RNC, is the main organization for the Republican Party in all 50 states. The Republican Party is not the same political party as the Democratic-Republican Party. A state where most voters vote for Republican politicians is called a red state.
History
The Republican Party was founded in Ripon, Wisconsin in 1853, with the help of Francis Preston Blair. The Republican Party was formed by people who did not like the Kansas-Nebraska Act of 1854, which would let each territory allow slavery. The Republican Party was founded by past members of the Free Soil Party and the Whig Party who wanted to stop the expansion of slavery. The founders of the Republican Party wanted to stop the expansion of slavery because they believed it was against the ideals of the Constitution and Declaration of Independence. Some founders of the Republican Party wanted to abolish slavery everywhere in the United States. The Republican Party's first candidate for president of the United States was John C. Frémont in 1856.
As the Whig Party collapsed, the Republicans became one of two major political parties in the United States (the Democratic Party was the other major political party). In 1860 Abraham Lincoln, the first Republican president, was elected. For the rest of the second half of the 19th century, the country had mostly Republican presidents. From 1860 until 1912 the Republicans lost the presidential election just twice (non-consecutively to Democrat Grover Cleveland in 1884 and 1892). Republicans believed in protectionism (the belief that raising taxes on trades with other countries would protect the economy) during the second half of the 19th century and during the early half of the 20th century. After World War I, the 1920s had three Republican presidents: Warren Harding, Calvin Coolidge, and Herbert Hoover. It was called the Republican Decade for that reason. Harding and Coolidge made a plan for the economy which lowered taxes, made the government spend less money, and got rid of rules and laws that affected the economy.
Near the end of the 1920s, the stock market crashed and the Great Depression began. During the Great Depression, the Republican Party became less popular. No Republicans were president between 1933 and 1953, when Dwight Eisenhower began his first of two consecutive terms as president (he was re-elected in 1956). Richard Nixon lost the election in 1960 but was elected president on the Republican ticket in 1968 and again in 1972. Ronald Reagan, an actor and conservative political activist, was elected as president in 1980. Ronald Reagan became the first Republican president who was a former member of the Democratic Party. Ronald Reagan served two terms and his successor George H.W. Bush served one term. Reagan wanted fewer laws to affect the economy and wanted the military to be stronger. Bill Clinton (a Democrat) was elected president in 1992, and re-elected in 1996. However, a new Congress was elected in 1994, and Republicans gained control of both the House of Representatives and the Senate. They voted against many of Clinton's ideas and proposed ideas of their own such as a line-item veto and a balanced budget amendment. In 2000, George W. Bush was elected president, defeating Al Gore in a very close election. Bush was re-elected in 2004.
After elections held in 2006, Republicans lost control of Congress. Democrat Barack Obama was elected in 2008 and re-elected in 2012. Republican John Boehner was elected the Speaker of the House of Representatives in 2010 and re-elected in 2012. In 2014, Republicans gained control of the Senate and the House. Boehner resigned in early October 2015 and was eventually succeeded by Paul Ryan of Wisconsin on October 29, 2015. On November 9, 2016, Donald Trump was elected president, defeating Democrat Hillary Clinton in the Electoral College. Trump was the first Republican to take office as president since January 20, 2001, when George W. Bush was inaugurated. The Republicans lost the House and won the Senate in 2018. Paul Ryan retired in 2019 and was succeeded by Nancy Pelosi, who is a member of the Democratic Party. In 2020, the Republicans lost the presidency when Joe Biden defeated Donald Trump. In 2022, they were able to get control back of the House of Representatives, but not the Senate. In 2024, the Republicans won the presidency again when Donald Trump defeated Kamala Harris. They were also able to hold their control of the House of Representatives, as well as gain control of the Senate.
 Republican beliefs 
Currently, the Republican Party is identified by classical liberalism, conservatism, and right-wing policies.
Most Republicans believe in the same things, but generally, these are the things many Republicans support in all:
Small government
Federalism and subsidiarity 
 Capitalism, laissez-faire, and supply-side economics
 Reduced government spending
 Aiding the State of Israel, the United States' allies, and defending American interests in the Middle East.
 Lower taxes
 A strong military and strong national defense with increased military spending
 The 2nd Amendment and allowing people to own guns
 Educational choice, e.g. a voucher system such as the D.C. Opportunity Scholarship Program.
 Oppose illegal immigration and support of deportation
 Oppose government-run health care
 Oppose letting students go to college or university for free
 Oppose declaring Washington D.C. an official state. 
 Oppose abortion
 Oppose homosexuals & Transgenders
 Oppose gay marriage
Most supporters for the Republican Party come from states in the Southern, Deep South, parts of the Midwest, and the rural Northeast areas of the US, as well as from Montana; though they come from all over the United States, including the northern portion of California.
 List of Republican presidents 
List of famous Republicans
Buzz Aldrin (US astronaut)
Abraham Lincoln (US president)
Susan B. Anthony (women's rights activist, abolitionist activist)
Clara Barton (Union Army Civil War nurse, humanitarian, Red Cross founder)
 Jeb Bush (Former governor of Florida, son of Former President George H. W. Bush and brother of Former President George W. Bush)
 Jan Brewer (Former governor of Arizona)
Dr. Ben Carson (U.S. Secretary of HUD under President Trump, retired neurosurgeon)
 Dick Cheney (Vice President under President George W. Bush)
 Chris Christie (Former Governor of New Jersey)
Bing Crosby (American singer and actor)
 Thomas Dewey (Presidential candidate in 1944 and 1948)
 Bob Dole (presidential candidate in 1996, former Senator from Kansas)
Elizabeth Dole (former Senator from North Carolina, former U.S. Secretary of Labor under President George Bush, former U.S. Secretary of Transportation under President Reagan)
John Ford (American film director and producer)
 Newt Gingrich (former speaker of the U.S. House of Representatives)
 Rudy Giuliani (former mayor of New York City, former presidential candidate, former US attorney)
 Barry Goldwater (presidential candidate in 1964, former Senator from Arizona)
 Chuck Hagel (a former senator from Nebraska, former U.S. Secretary of Defense)
Nikki Haley (UN Ambassador, former Governor of South Carolina)
Sean Hannity (a well-known talk show host on Fox News)
 Dennis Hastert (former speaker of the U.S. House of Representatives)
Orrin Hatch (former President Pro-tempore of the Senate)
 Jack Kemp (vice-presidential candidate in 1996)
Jeane Kirkpatrick (former UN Ambassador, professor)
 Henry Kissinger (former U.S. Secretary of State)
 Rush Limbaugh (a radio talk show host)
 Mia Love (former U.S. Representative)
 Richard Lugar (former senator from Indiana)
 John McCain (presidential candidate in 2008, former Senator from Arizona)
 Mitch McConnell (Senate Majority Leader)
 Sarah Palin (vice presidential candidate in 2008, former Governor of Alaska)
Dr. Rand Paul (Senator from Kentucky, physician)
Dr. Ron Paul (former U.S. Congressman from Texas, physician, author)
 Colin Powell (general during Persian Gulf War, Secretary of State)
Paul Robeson (American singer, actor, and Civil Rights activist)
 Nelson Rockefeller (Vice President under President Gerald Ford, former Governor of New York)
 Mitt Romney (former Governor of Massachusetts, presidential candidate in 2012, Senator from Utah)
 Paul Ryan (former Speaker of the US House of Representatives, vice presidential candidate in 2012, U.S. Congressman)
 Condoleezza Rice (former U.S. Secretary of State)
 Karl Rove (former strategist to President George W. Bush)
 Donald Rumsfeld (U.S. Secretary of Defense under President George W. Bush)
 Mark Sanford (Governor of South Carolina)
Arnold Schwarzenegger (American actor, former governor of California)
Elizabeth Cady Stanton (abolitionist activist, women's rights activist)
 Kenneth Starr (U.S. prosecutor of Democrat Bill Clinton)
 Michael Steele (Former chairman of the Republican National Committee)
 Ted Stevens (Former Senator from Alaska)
Dr. Mary Edwards Walker (Union Army Civil War doctor and surgeon, abolitionist activist, women's rights activist)
John Wayne (American actor)


Isaac Newton: Sir Isaac Newton GBR FRS PRS (25 December 1643 – 31 March 1727) was an English physicist, mathematician and astronomer. He is well known for his work on the laws of motion, optics, gravity, and calculus also, he presents his theory of universal gravitation and three laws of motion.
Newton built the first practical reflecting telescope in 1668. He also developed a theory of light based on the observation that a prism decomposes white light into the colors of the rainbow. Newton also shares credit with Gottfried Leibniz for the development of calculus. 
Newton's ideas on light, motion, and gravity dominated physics for the next three centuries, until modified by Albert Einstein's theory of relativity.
After being knighted in 1705 because he was Master of the Royal Mint, he was "Sir" Isaac Newton.
 Life 
 Early life 
Isaac Newton was born (according to the Julian calendar, in use in England at the time) on Christmas Day, 25 December 1642 (N.S. 4 January 1643) "an hour or two after midnight", at Woolsthorpe Manor in Woolsthorpe-by-Colsterworth, a hamlet in the county of Lincolnshire, England. His father, also named Isaac Newton, died three months before his birth. When Newton was three, his mother, Hannah Ayscough, remarried with Reverend Barnabas Smith. Young Newton remained with his maternal grandmother, Margery Ayscough.
From 1655 to 1659, Newton was educated at The King's School, Grantham. When he was seventeen, he was removed from school. His mother tried to make him a farmer, but he did not like that.Westfall 1994 16–19 Henry Stokes, master at The King's School, requested his mother to send him back to school.White 1997 22
In June 1661, he was sent to the University of Cambridge to study. In 1666 the University closed temporarily due to the Great Plague of London and he went home to Woolsthorpe to study.
 Discoveries 
In 1666 Isaac Newton experimented with light, and found that different colors had different refractions. He began lecturing on this topic in 1670.
Newton explained the workings of the universe through mathematics. He described laws of motion and gravitation. These laws are math formulas that explain how objects move when a force acts on them. 
1687, Newton published his most famous book called the Philosophiæ Naturalis Principia Mathematica 1687 while he was a mathematics professor at Trinity College, Cambridge. In the Principia, Newton explained three basic laws that govern the way objects move. He then described his idea, or theory, about gravity. Gravity is the force that causes things to fall down. If a pencil fell off a desk, it will land on the floor, not the ceiling. In his book Newton also used his laws to show that the planets revolve around the suns in orbits that are oval, not round. Newton also discovered diffraction. This led him to enter the field of physics, where he prospered.
 Newton's Three Laws Of Motion 
Following are the three laws of motion.
 The first law (Law of Inertia)
 Newton's first law of motion states is that an object that is not being pushed or pulled by some force will stay still, or will keep moving in a straight line at a steady speed. It is easy to understand that a rocket will not move unless something pushes or pulls it. It is harder to understand that an object will continue to move without help. Think of the rocket again. If someone is flying a rocket and jumps off before the rocket is stopped, what happens? The rocket continues on until it goes into space. The tendency of an object to remain still, or keep moving in a straight line at a steady speed is called inertia.
 The second law (Law of Acceleration)
 The second law explains how a force acts on an object. An object accelerates in the direction the force is moving it. If someone gets on a bicycle and pushes the pedals forward the bicycle will begin to move. If someone gives the bicycle a push from behind, the bicycle will speed up. If the rider pushes back on the pedals the bicycle will slow down. If the rider turns the handlebars, the bicycle will change direction. The formula showing this law is F=m*a, or the force acting on an object is equal to mass times acceleration.
 The third law (Law of Reciprocal Actions)
 The third law states that if an object is pushed or pulled, the object will push or pull equally in the opposite direction. If someone lifts a heavy box, they use force to push it up. The box is heavy because it is producing an equal force downward on the lifter’s arms. The weight is transferred through the lifter’s legs to the floor. The floor presses upward with an equal force. If the floor pushed back with less force, the person lifting the box would fall through the floor. If it pushed back with more force the lifter would fly into the air.
One proposed "zeroth law" is the fact that at any instant, a body reacts to the forces applied to it at that instant. Likewise, the idea that forces add like vectors (or in other words obey the superposition principle ), and the idea that forces change the energy of a body, have each been proposed as a "fourth law".
 The discovery of the Law of Gravitation 
When people think of Isaac Newton, many think of him sitting under an apple tree watching an apple fall. Some people believe the apple fell onto his head. Newton understood that what makes things like apples fall to the ground is a specific kind of force — the force we call gravity. Newton thought that gravity was the force of attraction between two objects, such as an apple and the earth. He also thought that an object with more matter exerted the same force on smaller objects as they exerted on it. That meant that the large mass of the earth pulled objects toward it. That is why the apple fell down instead of up, and why people do not float in the air.
Isaac Newton went on thinking about gravity. Before Newton, people thought that only objects near to the earth would fall down. But Newton thought that gravity should not just be limited to the earth and the objects on it. What if gravity went to the moon and beyond?
Newton invented a formula for calculating the force of attraction between two bodies. He used it to calculate the force needed to keep the moon moving around the earth. Then he compared it with the force that made the apple fall downward. After allowing for the fact that the moon is much farther from the earth, and has a much greater mass, he discovered that the forces were the same. The moon is held in an orbit around the earth by the pull of earth’s gravity.
The formula invented by Newton is called the Law of gravitation.
 Impact 
Sir Isaac Newton’s calculations changed the way people understood the universe. No one had been able to explain why the planets stayed in their orbits. What held them up? Less than 50 years before Isaac Newton was born it was thought that the planets were held in place by an invisible shield. Isaac proved that they were held in place by the sun’s gravity. He also showed that the force of gravity was affected by distance and by mass. He was not the first to understand that the orbit of a planet was not circular, but more elongated, like an oval. What he did was to explain how this and other parts of celestial mechanics worked.
Isaac Newton was the first to discover the laws of gravitation and the laws of motion. He also established a new field in mathematics known as calculus, though the German Gottfried Leibniz had developed the ideas at the same time. His work has greatly contributed in the areas of science and mathematics making him one of the most influential scientists in human history and one of the greatest mathematician of all times.
The great physicist, Albert Einstein, thought that Newton's idea of gravity was not completely accurate. He corrected many of the things that Newton did.
 Death 
Isaac Newton died on 20 March 1728 in London, England.
He is buried in Westminster Abbey. He set the stage for many famous physicists to come. such as Albert Einstein, James Chadwick, and Stephen Hawking.


Slavery in the United States: Slavery in the United States was the legal institution of human slavery in the United States. Slaves were mostly Africans and African Americans. Slavery existed in the United States of America in the 18th and 19th centuries. Slavery existed in British America from early colonial days. Slavery was legal in all Thirteen Colonies at the time of the Declaration of Independence in 1776. It lasted in about half the states until 1865. This was when it was banned in the entire country by the Thirteenth Amendment.
By the time of the American Revolution (1775–1783), slaves had been institutionalized as a racial caste. The caste associated with African ancestry. When the United States Constitution was ratified in 1789, a small number of free people of color were able to vote. This was because they were men who owned property. During and shortly after the Revolutionary War, abolitionist laws were passed in most Northern states, and there was a movement created to end slavery. Slave states tried to extend slavery into new Western territories. They wanted to do this to keep their share of political power in the country. Southern leaders also wanted to annex Cuba as a slave territory. The United States became split over the issue of slavery. It was split into slave and free states. The Mason–Dixon line divided the country. The line divided (free) Pennsylvania from (slave) Maryland.
While Jefferson was president, Congress prohibited the importation of slaves, effective 1808. Although smuggling (illegal importing) through Spanish Florida was common. Slave trading within the United States, however, continued at a fast pace. This was because there was a need for labor due to the creation of cotton plantations in the Deep South. New communities of African-American culture were created in the Deep South. There were 4 million slaves in the Deep South before they were set free.
Colonial America
The first Africans came to the New World with Christopher Columbus in 1492. An African crew member named Juan Las Canaries was on Columbus's ship. Shortly after, the first enslavement happened in what would later be the United States. In 1508, Ponce de Leon created the first settlement near present-day San Juan. He started enslaving the indigenous Tainos. In 1513, to supplement the decreasing number of Tainos people, the first African slaves were imported to Puerto Rico.
The first African slaves in the continental United States came via Santo Domingo to the San Miguel de Gualdape colony (most likely in the Winyah Bay area of present-day South Carolina). It was created by Spanish explorer Lucas Vázquez de Ayllón in 1526.
On August 28, 1565, St. Augustine, Florida was created by the Spanish conquistador Don Pedro Menendez de Aviles. He brought three African slaves with him. During the 16th and 17th centuries, St. Augustine was the where a lot of the slave trade in Spanish colonial Florida happened. It was the first permanent settlement in the continental United States to have African slaves.
60 years later, in the early years of the Chesapeake Bay settlements, colonial officials found it difficult to convince people to come and work for them. This was because the weather and environment of the settlements was very harsh. There was a very high chance that people would die. Most people came from Great Britain as indentured laborers. They signed contracts that said they would pay with work for their transportation, their upkeep, and their training, usually on a farm. The colonies had agricultural economies. These people were often young people who wanted to become permanent residents. In some cases, convicted criminals were sent to the colonies as indentured laborers, rather than being sent to prison. These people were not slaves, but they were required to work for four to seven years in Virginia to pay for the cost of their transportation and maintenance. Many Germans, Scots-Irish, and Irish came to the colonies in the 18th century, settling in the backcountry of Pennsylvania and further south.
The first 19 or so Africans to reach the English colonies arrived in Jamestown, Virginia, in 1619. They were brought by English privateers who had seized them from a captured Portuguese slave ship. Slaves were usually baptized in West Africa before sending them. As English custom then considered baptized Christians exempt from slavery, colonists treated these Africans as indentured servants. The African indentured servants joined about 1,000 English indentured servants already in the colony. The Africans were freed after a period of time. They were also given the use of land and supplies by their former masters. 
There were no laws about slavery in Virginia's early history. However, in 1640, a Virginia court sentenced John Punch, an African, to slavery. This was because he tried to run away from his service. He ran away with two white people. The two white people were sentenced only to one more year of their indenture, and three years' service to the colony. This is the first legal sanctioning of slavery in the English colonies. It was one of the first legal distinctions made between Europeans and Africans.
In 1641, Massachusetts became the first colony to allow slavery through law. Massachusetts passed the Body of Liberties. It banned slavery in many cases, but it allowed slaves to be held if they were prisoners of war, if they sold themselves into slavery or were bought somewhere else, or if they were sentenced to slavery as punishment by the government. The Body of Liberties used the word "strangers" to refer to people bought and sold as slaves; they were generally not English subjects. Colonists believed this term referred to Native Americans and Africans.
During most of the British colonial period, slavery existed in all the colonies. Slaves in the North usually worked as house servants, artisans, laborers, and craftsmen. Most were in cities. Many men worked on the docks and in shipping. In 1703, more than 42 percent of New York City households had slaves. New York City had the second-highest proportion of slaves of any city in the colonies after Charleston, South Carolina. Slaves were also used as agricultural workers in farming communities. This included areas of upstate New York and Long Island, Connecticut, and New Jersey. By 1770 there were 397,924 Blacks in a population of 2.17 million. They were not spread out evenly. There were 14,867 in New England where they were 2.7% of the population; 34,679 in the mid-Atlantic colonies where they were 6% of the population (19,000 were in New York or 11%); and 347,378 in the five southern colonies where they were 31% of the population.
The South developed an agricultural economy. It relied on commodity crops. Its planters quickly got more slaves. This was because its commodity crops were labor-intensive.
Revolutionary Era
While there were some African slaves that were kept and sold in England, slavery in Great Britain had not been allowed by statute there. In 1772, it was made unenforceable at common law in England and Wales by a legal decision. The big British role in the international slave trade continued until 1807. Slavery continued in most of Britain's colonies. Many rich slave owners lived in England and had a lot of power.
In early 1775 Lord Dunmore, royal governor of Virginia, wrote to Lord Dartmouth. He wrote he was going to free slaves owned by Patriots in case they rebelled. On November 7, 1775, Lord Dunmore issued Lord Dunmore's Proclamation which declared martial law. He promised freedom for any slaves of American patriots who would leave their masters and join the royal forces. Slaves owned by Loyalist masters, however, were not going to be freed by Dunmore's Proclamation. About 1500 slaves owned by Patriots ran away and joined Dunmore's forces. Most died of disease before they could do any fighting. Three hundred of these freed slaves made it to freedom in Britain.
Many slaves used the war to run away from their plantations. They would run into cities or woods. In South Carolina, nearly 25,000 slaves (30% of the total enslaved population) ran away, migrated, or died during the war. In the South, many slaves died, with many due to escapes. Slaves also escaped throughout New England and the mid-Atlantic, joining the British who had occupied New York.
Slaves and free blacks also fought with the rebels during the Revolutionary War. Washington allowed slaves to be freed who fought with the American Continental Army. Rhode Island started enlisting slaves in 1778. Rhode Island promised money to owners whose slaves enlisted and lived to gain freedom. During the course of the war, about one fifth of the northern army was black. In 1781, Baron Closen, a German officer in the French Royal Deux-Ponts Regiment at the Battle of Yorktown, estimated the American army to be about one-quarter black. These men included both former slaves and free blacks.
In the 18th century, Britain became the world's biggest slave trader. Starting in 1777, the Patriots made importing slaves illegal state by state. They all acted to end the international trade. However, it was later reopened in South Carolina and Georgia. In 1807 Congress acted on President Jefferson's advice and made importing slaves from other countries a federal crime, as the Constitution permitted, starting January 1, 1808.
1790 to 1860
"Fancy ladies"
In the United States in the early nineteenth century, owners of female slaves could freely and legally use them as sexual objects. This is similar to the free use of female slaves on slave ships by the crews.83
"Fancy" was a code word that meant the girl or young woman was able to be used for or trained for sexual use.56 Sometimes, children were also abused like this. The sale of a 13-year-old "nearly a fancy" is documented.
Furthermore, females who were able to become pregnant were supposed to be kept pregnant, so they could make more slaves to sell. The differences in skin color found in the United States make it obvious how often black women were impregnated by whites.78–79 For example, in the 1850 Census, 75.4% of "free negros" in Florida were described as mulattos, of mixed race.2 Nevertheless, it is only very recently, with DNA studies, that any sort of reliable number can be provided, and the research has only begun. Light-skinned girls, who contrasted with the darker field workers, were preferred.
Blacks who owned slaves
Some slave owners were black. An African former indentured servant who settled in Virginia in 1621, Anthony Johnson, became one of the earliest documented slave owners in the American colonies. This was documented when he won a civil lawsuit to own a man named John Casor. In 1830, there were 3,775 black slave owners in the South. They owned a total of 12,760 slaves. 80% of the black slave owners lived in Louisiana, South Carolina, Virginia, and Maryland.
Last slaves and freedom (1865)
In 1865 general Gordon Granger of the Union Army led a military occupation army into Galveston, Texas and set the last slaves free.


2020 in the United States: 2020 the United States
Events from the year 2020 in the United States.
 Events 
 January 
 January 3 — A U.S. airstrike near Baghdad International Airport kills Iranian military general Qasem Soleimani, fueling the Persian Gulf crisis.
 January 16 – The impeachment trial of the President of the United States, Donald Trump, starts in the U.S. Senate.
 January 26 – Five-time NBA champion Kobe Bryant, his 13 year-old daughter Gianna and seven others are killed in a helicopter crash in Calabasas, California.
 January 28 — President Donald Trump and Israeli Prime Minister Benjamin Netanyahu announce the Trump peace plan.
 February 
 February 5 
Academy Award-winning actor Kirk Douglas died in Los Angeles, aged 103.
President Donald Trump is found innocent during his impeachment trial by the U.S. Senate.
 February 13 — NASA publishes a detailed study of Arrokoth, the most distant body ever explored by a spacecraft, which New Horizons passed by on its journey through the Kuiper Belt.
 February 27 – The Dow Jones Industrial Average plunges by 1,190.95 points, or 4.4%, to close at 25,766.64, its largest one-day points decline in history. This follows several days of large falls, marking the worst week for the index since 2008, triggered by fears of the spreading coronavirus. This would cause a massive global stock market crash.
 February 28 – Ambassadors of all 29 NATO Allies meet in the North Atlantic Council expressing solidarity with Turkey after 33 Turkish soldiers were killed in an air strike by the Syrian government forces during the ongoing Syrian civil war.
 February 29 
A truce is signed between American troops, Afghan troops, and the Taliban.
 March 
 March 3 - Several tornadoes tear through Nashville, Tennessee, killing 25.
 March 5 – The I.C.C. approves the Afghanistan War Crimes Inquiry to begin, allowing for the first time for U.S. citizens to be investigated.
 March 16 – Oil prices fall into the $20 range, down 10 percent from the previous day amid the coronavirus pandemic, as The Fed cuts interest rates to zero.
 March 20 – Country music singer Kenny Rogers dies at the age of 81.
 April 
 April 2 – 2019–20 coronavirus pandemic: Over 1,000,000 cases of COVID-19 are confirmed worldwide.
 April 5
 2019–20 coronavirus pandemic: The first case of COVID-19 in a zoo animal is reported; a four-year-old female Malayan tiger at the Bronx Zoo in New York.
 April 10 – 2019–20 coronavirus pandemic: The death toll from COVID-19 exceeds 100,000 globally, a ten-fold increase from March 20.
 April 12–13 – At least thirty people are killed in an Easter Sunday tornado outbreak in the Southeastern United States.
 April 15
 2019–20 coronavirus pandemic: The number of confirmed cases of COVID-19 passes 2 million worldwide.
 April 18–April 19 – At least 23 people are killed at random at several places in Nova Scotia, Canada. It was the deadliest attack of its kind in Canadian history.
 April 25 – 2019–20 coronavirus pandemic: The death toll from COVID-19 exceeds 200,000 globally. The U.K. becomes the fifth country to report 20,000 deaths.
 April 27 – 2019–20 coronavirus pandemic: The number of confirmed cases of COVID-19 passes 3 million worldwide, while the number of confirmed cases of COVID-19 in the United States passes 1 million.
 May 
 May 1
 In the aftermath of the 2020 Nova Scotia attacks, Canada bans assault-style weapons.
 2019–20 coronavirus pandemic: U.S. Food and Drug Administration authorizes emergency remdesivir use to treat the sickest COVID-19 patients.
 2019–20 coronavirus pandemic: The total number of recovered COVID-19 patient reached 1 million worldwide, according data from Johns Hopkins University.
 May 9 – Rock and Roll pioneer Little Richard dies at the age of 87.
 May 10
 COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 4 million worldwide.
 May 14
 COVID-19 pandemic:
 The global death toll from COVID-19 exceeds 300,000.
 The UN warns of a global mental health crisis caused by isolation, fear, uncertainty and economic turmoil.
 May 21 – COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 5 million worldwide, with 106,000 new cases recorded over the past 24 hours, the highest single-day figure so far.
 May 26 – Massive riots and protests break out in the United States following the police killing of George Floyd in Minneapolis, Minnesota.
 May 27
 U.S. Secretary of State Mike Pompeo says that Hong Kong is "no longer autonomous", as China backs a new security law that would make it a crime to undermine Beijing's authority in the territory.
 COVID-19 pandemic: The U.S. death toll passes 100,000 – more Americans then were killed in the Vietnam and Korean wars combined, and approaching that of the First World War, when 116,000 Americans died in combat. The total number of cases continues to rise, although the rate is slowing.
 May 30 – The first crewed flight of the Dragon 2 (initially scheduled for May 27 but delayed due to weather) is launched from Cape Canaveral, Florida, the first manned spacecraft to take off from U.S. soil since 2011.
 May 31 – COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 6 million worldwide.
 June 
 June 1 – Killing of George Floyd: After a week of rioting, U.S. President Donald Trump officially labels Antifa as a terrorist organization.
 June 2 – A US$5 billion lawsuit is filed against Alphabet Inc. and Google, saying that the company violates users' right to privacy by tracking them in Chrome's private browsing Incognito mode.
 June 3 – SpaceX successfully launches and deploys 60 satellites into a low Earth orbit from Cape Canaveral Air Force Station. This brings the total number of Starlink satellites in orbit to 482.
 June 7 – COVID-19 pandemic: The global death toll from COVID-19 exceeds 400,000.
 June 8
 COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 7 million worldwide.
 June 16
 COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 8 million worldwide.
 June 20 – Three people are killed and three more are injured during a terrorist knife attack at Forbury Gardens in Reading, Berkshire.
 June 28
 COVID-19 pandemic:
 The number of confirmed cases of COVID-19 passes 10 million worldwide. The U.S. continues to have the highest number of any country as it reaches 2.5 million, a quarter of all cases globally.
 The global death toll from COVID-19 exceeds 500,000.
 July 
 July 3 – COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 11 million worldwide.
 July 8
 COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 12 million worldwide.
 July 13 – C/2020 F3 (NEOWISE) can be seen by the naked eye and becomes one of the brightest visible to observers in the northern hemisphere since Comet Hale–Bopp in 1997.
 July 14 – The United States government passes the Hong Kong Autonomy Act.
 July 15 – The Twitter accounts of well known political figures, CEOs, and celebrities are hacked to promote a bitcoin scam.
 July 22 – COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 15 million worldwide.
 July 24 – Television host Regis Philbin dies at the age of 88.
 July 25 – Hurricane Hanna makes 2 landfalls in South Texas with 90 mph winds (145 km/h) mainly in Kennedy County, Texas.
 July 26 – Academy Award-winning actress Olivia de Havilland died in Paris, aged 104.
 July 30 – Successful launch of NASA's Mars 2020 mission to study the habitability of Mars in preparation for future human missions.
 August 
August 5
U.S. Secretary of Health and Human Services Alex Azar travels to Taiwan, the highest U.S. official visit to the country in 40 years. The PRC condemns the visit.
COVID-19 pandemic: The worldwide death toll from COVID-19 passes 700,000.
 August 10 
COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 20 million worldwide.
 August 12
It is reported that Britain's gross domestic product (GDP) fell by 20.4% in the second quarter of 2020, the biggest quarterly decline since records began in 1955, and the worst economic figure of any G7 nation.
 August 26 – Amazon CEO Jeff Bezos becomes the first person in history to have a net worth of $200 billion, according to Forbes.
 August 28 – Black Panther actor Chadwick Boseman dies of colon cancer at age 43.
 August 30 – COVID-19 pandemic: The number of confirmed cases of COVID-19 passes 25 million worldwide. India continues to record the highest daily increase of cases.
 September 
 October 
 November 
 December


2024 United States presidential debates: The 2024 United States presidential debates were a series of debates held during the upcoming 2024 U.S. presidential election. The first general election debate between two major party candidates was moderated by CNN and attended by then-presumptive Democratic nominee Joe Biden and then-presumptive (at that time) Republican nominee Donald Trump on June 27, 2024.Trump was not the Republican nominee until on July 15, 2024, when the 2024 Republican National Convention was opening. After the first debate, Biden withdrew from the race in July because of his poor performance, and Vice President Kamala Harris has replaced by being selected as the Democratic presidential nominee, while Trump became the official Republican nominee in the same month. The second debate, which was moderated by ABC, was held on September 10, 2024.
There were previously four debates sponsored by the Commission on Presidential Debates (CPD) scheduled between September 16 and October 9, 2024. Biden and Trump both objected and scheduled a debate themselves.
After Biden withdrew from the race, Trump suggested that the September 10 debate should be held by Fox News. Trump also suggested about additional debates on September 4 on Fox News and September 25 on NBC, the Harris campaign has not yet announced whether would participate in the two additional debates, instead of negotiating a presidential debate in October.
A vice presidential debate was held on October 1, 2024 on CBS News.
 List 
 Debates 
 First presidential debate 
The first presidential debate takes place on June 27, 2024, on Thursday, at 9:00 p.m. (U.S. Eastern Time) in Atlanta, Georgia. CNN held the debate.
The debate lasted 90 minutes. Trump spoke 4 minutes more than Biden (Trump spoke for 40 minutes and 12 seconds, Biden for 35 minutes and 41 seconds). There were 20 questions not counting the conclusion. Jake Tapper and Dana Bash were the moderators. During the debate, Biden often stuttered, spoke unclearly or even misspoke, which considered as the main reason of Biden withdrawal. Biden went off topic about 30% of the time during the debate, while Trump went off topic about 50% of the time. Both attacked each other during the debate.
There was no audience or handshake before the debate, similar to the 2020 debate four years earlier.
 Fast-checking 
Moderators were criticized for not fact-checking both during the debate, according to journalist Daniel Dale of CNN, Trump made about 30 false claims while Biden made about 9 false claims during the debate.
 Viewership 
CNN reported that 47.9 million people watched the first debate, down more than 20 million from 73 million viewers in 2020. But it was later re-reported at 51.3 million.
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 Reactions 
Trump was seen as the winner by many news, including The Hill, CNN, The New York Times, while some news, MSNBC and The Guardian, said neither Biden nor Trump won.
A CNN poll found that 67% of respondents said Trump won the debate, compared to 33% who said Biden won. Biden's performance was widely considered "a disaster" in the history of television and presidential debates by a sitting president.
Biden later claimed to have a cold and was tested for COVID-19 while at Camp David, which came back negative. Biden attended a debate watch party immediately after the debate, where many of his supporters and Biden called it the reason “America is so good.”
Biden also stated that "it's hard to argue with a liar," referring to Trump, then said that a New York Times article showed that Trump made more false claims than he did. Biden was congratulated on his performance by his wife, First Lady Jill Biden, at a post-debate conference. She told him on stage that he did “a fantastic job. He answered every question.” Biden’s running mate, Vice President Kamala Harris, said that although Biden “started slowly,” he managed to have a strong finish.
Several other Democrats have also called for unity and wished Biden well, adding that it is necessary to join hands to help Biden, such as California governor Gavin Newsom, two former Presidents Barack Obama and Bill Clinton.
Internationally, things are not looking good either, as top officials often worry or ridicule Biden for his poor performance, many European countries are extremely concerned about the debate, while Russian state media mocked Biden's performance.
 Calls for Biden to drop out 
Following the debate, many Democratic officials began calling for Biden to drop out. One day before Biden withdrew, 38 Democratic in House of Representatives and Senate called on Biden to stop running, including four independents that caucus with Democrats. With U.S. representatives Lloyd Doggett of Texas becoming the first to call on him to end his presidential campaign, a growing number of Democrats have since called on Biden to end his candidacy.
Biden has repeatedly refused to give up, the 2024 NATO summit in Washington is considered another motivation for Biden to ignore the doubts after the debate, but during the conference, Biden mistakenly called Vice President Kamala Harris 'Vice President Trump', as well as mistakenly called Ukrainian President Volodymyr Zelenskyy 'President Putin', which further raised doubts, and more and more people are calling for him to give up.
On July 21, 2024, Biden suspended his presidential campaign, endorsing Vice President Kamala Harris for president.
 Second presidential debate 
The second presidential debate takes place on September 10, 2024, on Tuesday, at 9:00pm (U.S. Eastern Time) at the National Constitution Center in Philadelphia, Pennsylvania. ABC held the debate. David Muir and Linsey Davis were the moderators.
Previously, Trump and Biden both agreed to a second debate, after Biden withdrew, Kamala Harris became the Democratic presidential candidate. Trump changed his mind and wanted to transfer ABC to Fox News as the manager. There were many doubts about whether the second debate would take place. Trump tweeted on Truth Social on September 2 that he was “terminating” the debate on ABC and moving it to Fox News instead. Harris said she would still appear on ABC as agreed whether Trump showed up or not. On August 8, Trump announced that he would rejoin the ABC debate, but he made it conditional on Harris participating in other debates. On August 27, Trump withdrew his request and pledged to rejoin the ABC debate.
Harris and Trump both met ABC's criteria to participate in the debate.
This is also the first time the two candidates from the two major parties have shaken hands, something that has not happened in any debate since 2016. Before the debate began, there were false reports that Haitian immigrants in Springfield, Ohio, were stealing and eating cats and dogs. Trump also raised the issue during the debate. His opponent, Harris, just laughed when he heard it.
During the debate, Harris often smirked, grinned or shook her head, looking at her opponent or the camera, when Trump answered, while Trump often showed annoyance and frowned. Trump also frequently refers to Harris as a Marxist and a communist, Trump also makes many false claims, disinformation, Harris and Trump often attack each other, Trump even compares Harris as "the worst vice president in US history" and Biden "the worst president in US history".
Harris and Trump also talked about crowd size at campaign rallies during debate.
Trump was also asked about the January 6 attack, whether he regretted it, to which he said no and changed the subject, criticizing then-House Speaker Nancy Pelosi for "not sending in the National Guard."
Trump and Harris were asked about the war between Russia and Ukraine. Trump did not directly answer, saying that he did not want anyone to die in the war and wanted the war to end. Harris said that Trump "supported" and "conceded" to Putin and said that if Russia invaded Ukraine while he was president, Putin "would be sitting in Kyiv". She also criticized Trump's statement that the war would end in 24 hours. Trump groused that Putin actually loves Harris: "Putin endorsed her last week. Said I hope she wins. And I think he meant it." Kremlin Spokesman Dmitry Peskov said later the debate that "Leave our president alone".
 Fast-checking 
Moderators fast-checked candidates during the debate, but were accused of fast-checking only Trump and leaving out Harris.
Both Harris and Trump made false claims, with Trump claiming that immigrants in Springfield, Ohio were eating pets, to which moderator David Muir responded that there were no credible reports of pets being harmed. Trump countered by claiming that he had seen TV interviews in which people said their dogs had been taken and eaten. Harris falsely claimed that during Trump's tenure there had been more unemployment than since the Great Depression. Harris also falsely claimed that no members of the US military were actively serving in a war zone, with the US military's Central Command soon after issuing a statement saying that they had engaged multiple Houthi targets in Yemen in the past 24 hours.
 Viewership 
Nielsen Media Research reported that 67.1 million viewers across ABC and 16 other television networks watched the debate, up from 51.3 million who watched the June 27 presidential debate between Biden and Trump, but still lose for more than 5 million viewers compared to the first 2020 presidential debate.
 Reactions 
Harris was seen as the winner by CNN, Politico, The New York Times, The Guardian, and MSNBC.
A CNN poll found that 63% of people believed Harris won the debate, while 37% thought Trump won. Trump's performance was widely seen as problematic, similar to Biden's.
One of Trump's statements, "They're eating the dogs ... they're eating the cats ... they're eating the pets," became an Internet meme, most notably on the short-form video sharing platform TikTok, along with Harris's expression. Trump's eating cat claims are considered his weakest point, while others find the claim unbelievable.
Despite being seen as the debate winner, Harris still struggles with public recognition and policy changes because she is still less well-known than Biden.
 Vice presidential debate 
The vice presidential debate was held on Tuesday, October 1, 2024, at 9:00 p.m. (U.S. Eastern Time) at the CBS Broadcast Center in New York City, New York. CBS News hosted the debate, with Margaret Brennan and Norah O'Donnell serving as moderators.
After Biden suspended his campaign, a vice presidential debate was in doubt, as previously after JD Vance was selected as the Republican vice presidential nominee, he hoped to debate Vice President Kamala Harris, after Harris selected Minnesota Governor Tim Walz as her running mate, Walz said he would love to debate Vance.
Both vice presidential candidates prepared before the debate.
The debate, broadcast by CBS News, lasted more than 90 minutes, with both candidates' microphones on while the other spoke, a precedent not seen in the 2024 presidential debates, although CBS said in a press release that it "reserves the right to mute candidates' microphones." Neither vice presidential candidate was allowed to ask questions of the other, only the moderator. At the end of the debate, Walz gave the first closing remarks, followed by Vance. CBS has said it will not fact-check, which will happen after the debate. Walz spoke more than Vance during the debate, Walz spoke for about 40 minutes and 42 seconds, while Vance spoke for 38 minutes and 59 seconds, according to CNN.
The two talked about climate change, the economy, immigration, abortion and even the carnivore allegations in Springfield, Ohio. As for the economy, Vance said Harris' economic agenda sounded pretty good, but implied that she "could do it as vice president if she wanted to, and he blamed her for many of the country's economic challenges, claiming that many voters trust Trump more on the economy." When Walz spoke about Amber Thurman, a woman lived in the state of Georgia who died after a delay in having fetal tissue removed from her body following a medication abortion, Vance said, “I agree with you. Amber Thurman should be alive.” Vance also said he does not support a nationwide abortion ban, although he did support a “national minimum standard” when he ran for the Senate. During the debate, Trump tweeted that he would veto any bill that would ban abortion nationwide.
 Fast-checking 
As mentioned above, CBS will not fact-check the candidates until the debate is over. However, moderators also questioned Vance about Haitian immigrants in Springfield, Ohio, which Vance later objected to due to CBS rules, adding that immigrants should not be considered legal because the federal government decided their protected status after they arrived in the United States, Walz rejected Vance's argument and the microphone was turned off while Vance was speaking.
 Viewership 
Nielsen Media Research reported that 43 million viewers tuned in to watch the debate, down more than 14 million viewers from the 57 million viewers who watched the 2020 vice presidential debate.
 Reactions 
Vance was declared the winner by The New York Times, The Wall Street Journal, USA Today, and The Los Angeles Times. A columnist from MSNBC said Walz the winner of the debate. According to polls, the debate was considered a tie, with a CNN poll showing Vance narrowly winning over Walz, with 51% of people thinking Vance won while 49% thought Walz won.
Vance's debate performance was positively reviewed by experts, with commentators from major newspapers such as The Washington Post and Reuters surprised by the focus on policy and civility towards each other compared to the two previous divisive presidential debates.
 Other debates 
Many debates and forums were held, mostly moderated by the Free and Equal Elections Foundation.


History of the United States (1789–1849): The History of the United States (1789–1849), sometimes called the Antebellum period, is the history beginning with the Presidency of George Washington and ending just before the American Civil War. The first government, formed under the Articles of Confederation, had ended and a new government based on the United States Constitution began. In the early 19th century, the country went though a number of dramatic changes. The country expanded its borders, cities became industrial centers and the economy grew. Sections of the United States developed differently leading to conflicts and eventually up to a civil war. 
 Federalist Era 
This is the period from 1789 to about 1801 when the Federalist Party controlled the American government.The word antebellum means the period before a war. It especially applies to the American Civil War. The years that made up the antebellum period are not agreed on by all historians. Some sources define the period as from 1820 to 1860. Others use the date 1789 as the beginning of the period leading up to the Civil War.
In 1789, Washington was elected the first President of the United States. The Constitution only gave a vague outline of what a president should be. Washington defined the position of President and left office after two terms. During Washington's term, there was a Whiskey Rebellion, where country farmers tried to stop the government from collecting taxes on whiskey. In 1795, Congress passed the Jay Treaty, which allowed for increased trade with Britain in exchange for the British giving up their forts on the Great Lakes. However, Great Britain was still interfering with the U.S., such as impressment (making American sailors join the British Royal Navy). 
John Adams defeated Thomas Jefferson in the election of 1796 to become the second President of the United States. This was the first American election that was between two political parties. Under Adams, the United States Navy was created on April 30, 1798. It replaced the earlier Continental Navy which had been disbanded by 1785. By the end of 1798 the U.S. Navy had 14 ships with more being built. Adams pushed for and signed the controversial Alien and Sedition Acts. 
In the election of 1800, Jefferson defeated Adams. One of the most important things he did as President was to make the Louisiana Purchase from France, which made the United States twice as big. By 1800 24 treaties had been signed with nine European powers.
 Jeffersonian period 
This is the period from 1800 through 1815 which includes the administrations of two Democratic-Republican Party presidents, Thomas Jefferson and James Madison. They are commonly called Jeffersonian Republicans. During this time the country nearly doubled in size with the Louisiana Purchase from France. This, in turn, was one of the causes behind the War of 1812, when Great Britain attempted to re-claim her former American colonies.<!Era of good feelings • http://www.ushistory.org/us/23a.asp -->
 Era of good feelings 
In 1816, the Federalist Party candidate Rufus King ran against the Democratic-Republican candidate James Monroe. Monroe received 183 electoral votes to King's 34. That was the last time the Federalist Party ran a candidate. The Congressional election of 1818 gave the Democratic-Republicans a majority of 85%. Monroe served for two terms from 1817 to 1825. Due to the dominance of one political party this is often called the "Era of Good Feelings". But the party was deeply divided by this time. Many of the Federalist policies of Alexander Hamilton were adopted during this time and Monroe continued many of the economic policies of Madison. Three in particular were a national bank, protective tariffs and federal funding of the infrastructure.
 Two party system 
The one-party Era of Good Feelings system of cooperation between politicians lasted only about a decade. It was replaced by a new two-party system,It is called a two party system because during the history of the United States there have usually been only two major political parties at any given time. These major parties are the only ones who had presidential candidates with a serious chance of becoming president. Many minor parties have existed and several have influenced American politics. A major party may break up from time to time, but it has been replaced by a new major party. which continues to today. Political parties took on the job of building coalitions between many different groups with different interests. This new system broke away from the patronage system based on personal loyalties. The Founding Fathers of the United States had never imagined a system based on political parties but by the 1830s they had become the main system of American politics.
The presidential election of 1824 had no Federalist party candidate. There were five candidates with Andrew Jackson winning the electoral college with 99 votes. Second to Jackson was John Quincy Adams with 84 votes and third was William H. Crawford who received 41 votes. Because nobody received a clear majority of electoral votes, following the Twelfth Amendment, the decision would be made by the House of Representatives.
The Speaker of the House was Henry Clay, another of the five candidates for President in 1824. Despite his state legislature instructing him to vote for Jackson, Clay formed a coalition to elect Adams president. On the first vote, Adams won the majority of votes. At first, Jackson accepted the decision gracefully. But after Adams became president he appointed Clay his Secretary of State. This brought cries of a "corrupt bargain" between Clay and Adams. Jackson's 1828 political campaign to end government corruption began immediately afterwards to make sure Adams would be a one-term president.
 Era of Jacksonian Democracy 
Andrew Jackson was elected president in 1828. He got nearly 70% of the electoral votes and over 60% participation in his election. This was largely due to Jackson's popularity as "Old Hickory", the hero of the Battle of New Orleans. His military career had included service in the Revolutionary War, the War of 1812 and the Seminole Wars. Jackson also benefited from the perceived corrupt bargain between Adams and Clay to expand his political base. 
During his presidency, Jackson founded the party that began calling itself the "American Democracy". Changes in the electoral rules and political campaigns also contributed towards the feeling the country was becoming more democratic than it had been up to this point. For both reasons this era was called Jacksonian democracy. The period itself was from 1828 into the 1840s but its influence lasted much longer. It was a period of democratic reforms in voting and changes to the structure of the federal government. Some historians see it as a contradiction in terms since it also defended slavery, the pushing of Native Americans westward and white supremacy. Jackson's policies during his two terms were best described as laissez-faire. 
 Democratic Party 
His Democratic Party stood for a smaller simpler government that did not involve itself in the economy or in regulating business. They opposed religious intrusion into government, especially in the forms of temperance, abolitionism and in officially keeping the Sabbath. Jackson and his Democrats wanted to keep government spending to a minimum.
The Democrats, under Jackson and his successor Martin Van Buren, became much better organized. They created a structure of local, state and national branches which controlled organizing membership as well as their caucuses and political conventions. They popularly claimed to be a grassroots party but were in fact controlled from Washington. They represented themselves as defending the common man against the "aristocrats" of the Whig Party. They started a spoils system of rewarding party loyalty with government jobs. After the War of 1812, Constitutional changes allowed more men to vote by erasing the requirement to own property. By Jackson's presidency, nearly all white men could vote. In 1812, only half of the states chose their electors in a presidential election by popular vote. By 1832, all states except South Carolina chose their presidential electors by popular vote. The Democrats were quick to take advantage of these changes. 
 Nullification Crisis 
Jacksonian Democrats fought against the Second Bank of the United States. They wanted to remove the political influence of bankers on the national economy. They helped farmers and planters by taking away the lands of Native Americans and making cheap land available for settlers. But this did not get them the support of all planters in the South. Mostly centered in South Carolina, some thought the Jacksonian egalitarianism might threaten the institution of slavery itself. This led to the Nullification Crisis of 1832-1833. Farmers and planters had hoped that when Jackson was elected, he would reduce the unpopular tariffs that benefited Northern manufacturers and hurt the economy of the South. South Carolina passed the Ordinance of Nullification which declared the federal tariffs of 1828 and 1838 illegal within the borders of South Carolina. They also began to raise funds for a military to defend themselves. 
In November 1832, Jackson sent a fleet of seven navy ships and one warship to Charleston. He called the state act "insurrection and treason". While other states in the south may have sympathized with South Carolina, they called the state's actions unconstitutional. South Carolina finally gave in and removed their objections to the tariff. In response, in 1833, Henry Clay got a bill through Congress that reduced the tariff in stages for any that were over 20%. So in the end South Carolina had shown it could force its will on Congress by resisting a federal law.
 Social reforms 
A number of reform movements began during this period after 1815. The improved economy after the War of 1812 provided a new class of people who had the time and financial resources to become involved in social movements. New technologies in printing increased the number of publications including those about subjects such as abolition. Better transportation meant lecturers could move from place to place more easily. A temperance movement began about 1819. A religious movement, sometimes called the Second Great Awakening, swept through the country during this time. Common themes ran through most of these reform movements. One of the most important was the belief that people had the ability to choose between right and wrong. For example, slavery was wrong. The term "slave" was used to show anything that was held to be wrong in society. Drunkards were "slaves" to alcohol, workers were "slaves" to the factory owners, and women were "slaves" to men. It was also common for those who believed in anti-slavement movements to also believe in women's rights, religious reforms and temperance reforms. People were given to joining local organizations because there were no strong political leaders championing these causes. There were no national church organizations to lead these causes. Reform movements went around the political and religious systems, at least until the 1840s. The movements themselves, such as the abolitionist movement, were not completely unified and had internal disagreements over what should be done or how to go about it.
 Antebellum slavery 
Slavery was mainly concentrated in the South by 1830. Slaves were used on small farms and large plantations. They were also used in towns as domestic workers and labor for various industries. Slaves were considered to be property because they were black. They were kept as slaves by the constant threat of violence. They were not allowed to forget they were slaves even though they lived with their masters. Many slaveowners genuinely cared about their slaves, but never saw them as their equal. But the largest percentage of Southerners did not own slaves. Most Southerners worked their own farms yet, curiously, they defended slavery as an institution. Many resented the wealth and power of the large plantation owners but at the same time held out the hope that someday they could join those ranks. Also, while poor Southerners were looked down on by rich plantation owners, they could themselves look down on blacks as an inferior group.
Cotton had become the largest cash crop. But plantations also grew corn, rice, sugarcane and tobacco. Slaves on plantations may have averaged 50 or less, but the largest plantations had hundreds of slaves. In addition to field work, slaves also were skilled in trades such as blacksmithing, carpentry and mechanics. Domestic slaves did the cooking for the family, raised their children and performed all the work in the household. They were always supervised and had to work at all times they were not sleeping. Domestic slaves had virtually no privacy. Young white children formed close attachment to their black nannies. But as they grew up they were educated as to how slaves were to be treated.
 The Agrarian South 
During this time period cotton plantations became very profitable in the South. Advances such as the cotton gin, power looms and the Sewing machine created a demand for cotton. It was exported from the South to New England and to England. Plantation owners needed more land and more slaves to grow more cotton. They were especially interested in expanding into new territories. They needed more slaves and after the ban on importing African slaves into the U.S., the prices went up. Small farmers found it profitable to sell their slaves to the large plantation owners. Wealth in the South often reflected how many slaves a planter owned. Slaves gave them political power and prestige.
 The industrial North 
The textile industry started the industrial revolution in the North. Other advances in manufacturing were in making paint, furniture, paper and glass. Between 1814 and 1865, the population grew by a factor of four. Manufacturing output grew to twelve times and the price of manufactured goods grew to eight times what it was before. Most of this growth was in New England. Rivers provided power for mills. In Pennsylvania coal and iron ore were mined. Agriculture remained an important industry in the North. Schools provided education provided a literate supply of workers and inventors. Large ports and ships provided transportation to foreign markets. Also railroads and water transportation such as the Erie Canal provided goods and services further west. A steady supply of immigrants provided much of the labor force that ran the Northern industries. During this period a number of social movements including anti-slavery began to have noticeable effects on society. In 1831 more radical forms of abolitionist movements emerged.
 U.S. presidents


Philosophy: Philosophy is the study of wisdom. grc Philosophia is the Ancient Greek word for the "love of wisdom".
A person who works in the field of philosophy is called a philosopher. A philosopher is a kind of thinker and researcher. A "philosophy" can also mean a group of ideas or way of living suggested by philosophers.
Philosophy is a way of thinking about the world, the universe, and society. In the past, natural sciences were a part of philosophy.
Ideas
The ideas in philosophy are often general and abstract. However, this does not mean that philosophy is not about the real world. For example, ethics talks about how to be good in our day-to-day lives. Metaphysics questions how the world works and what it is made of. Sometimes, people talk about how they have a ‘personal philosophy’, which means the way a person thinks about the world. This article is not about people's ’personal philosophies’. This article is about the ideas that have been discussed by philosophers.
Questions
Questions related to philosophy are called philosophical questions. Most philosophical questions can never be answered with certainty. They focus on important topics, such as the meaning of life, death, and morality. An example of a philosophical question is this: "Is there any knowledge in the world which is so certain that no reasonable man could doubt it?". Other questions asked by philosophers are:
 What should we do in our lives?
Why are we born?
Why are there so many difficulties in life?
How do we overcome suffering?
What is the importance of the material life?
Will the universe exist forever?
 What is beauty?
 Do we have free will?
 Does God exist?
 Does the world around us exist?
 What is truth? 
 What is evil?
 What is the relationship between mind and body?
 What is the meaning of life?
 If I discover the meaning of life and gain knowledge of the truth about the way everything in this universe works will it enhance any of the sensory ways in which we experience this physical existence or would my limited time here be better spent simply enjoying the here and now?
 What is consciousness?
 History 
The word 'Philosophy' directly translates to 'love of wisdom'. It comes from the Greek word 'Philosophia', with 'Philo' meaning 'lover' and 'Sophia' meaning 'wisdom.
There are different types of philosophy from different times and places. Some philosophers came from Ancient Greece, such as Plato and Aristotle. Others came from Asia, such as Confucius, Buddha, Adi Shankara, and Laozi. Some philosophers were from the Middle Ages in Europe, such as William of Ockham or Saint Thomas Aquinas.
Influential philosophers from the 1600s and 1700s include Thomas Hobbes, René Descartes, John Locke, Gottfried Leibniz, David Hume, and Immanuel Kant. Some major philosophers from the 1800s are Georg Hegel, Søren Kierkegaard, and Friedrich Nietzsche, whereas the 1900s gave us Martin Heidegger and Ludwig Wittgenstein.
 Areas of inquiry Philosophy seeks to understand truths about the world and how we view it. It tries to answer important questions by making conclusions based on observations of human nature and the real world.
Sometimes, philosophy tries to answer the same questions as religion and science. Philosophers give different answers to the same question. Many types of philosophy criticize or even attack the beliefs of religion.
In his work Critique of Pure Reason, Immanuel Kant asks the following questions:
What can I say? 
What shall I do?
What dare I hope?
What is man?
The answers to these questions give the different categories of philosophy.
 Categories in philosophy 
Philosophy can be divided into different groups based on the types of questions asked. Below is a list of the questions split into groups. One possible list of answers to these questions can be called a 'philosophy'. There are many different philosophies, because all of these questions have different answers according to different people. Not all philosophies ask the same questions. These are the questions that are usually asked by philosophers from the Western world:Metaphysics:
Metaphysics is sometimes split up into ontology (the philosophy of real life and living things), the philosophy of mind and the philosophy of religion; but these sub-branches are very close together.
Ontology:
 What is the world that we see around us? (What is reality?)
 Is there more to the world than what we see and hear?
 If nobody sees something happen, does that mean that it did not happen?
 What does it mean to say that something is possible? Do other worlds exist?
 Is there anything very special about being a human being, or being alive at all?
 If not, why do some people think that there is?
 What is space? What is time?
The philosophy of mind:
 What is a mind?
 What is a body?
 What is consciousness?
 Do people make choices, or can they only choose to do one thing? (Do people have free will?)
 What makes words or ideas meaningful? (What is the relation between meaningful words or ideas and the things that they mean?)
The philosophy of religion:
 Do people have souls?
 Is there a God who created the Universe?In epistemology:
 What is knowledge? 
 How can we know anything?
 What is science?
 What is truth?In ethics:
 What are right and wrong, good and bad?
 Should people do some things and not others?
 What is justice?In aesthetics:
 What is beauty? What if one person thinks a painting is beautiful, but another person thinks the painting is ugly? Can the painting be beautiful and ugly at the same time?
 Are true things beautiful?
 Are good things beautiful?
 What is art? We commonly think that a sculpture in a museum is art. If a sculptor sculpts a sculpture of a rock from clay, and puts it in a museum, many would call it art. But what if a person picks up a rock from the ground - is the rock a piece of art?In logic:
 What do the words we use mean?
 How can we say things (especially ideas) in a way that only has one meaning?
 Can all ideas be expressed using language?
 How does the truth of an argument's premise affect the truth of its conclusion?
 How can we reason correctly?In axiology'
 What has value?
 Is time really money? or have we made it so?
 Does love, beauty, or justice hold any value?
Other divisions include eschatology, teleology and theology. In past centuries, natural science were included in philosophy, and called "natural philosophy".
 Is philosophy good or bad? 
It is easy to argue that philosophy is a good thing because it helps people understand the world better. Philosophy helps people learn how to act and think. Philosophers believe that asking philosophical questions is useful because it helps people learn about themselves, the world, and others. It can be argued that "Is philosophy good or bad?" is a philosophical question itself.
However, some people think philosophy is harmful because it encourages free-thinking and questions the beliefs that others hold. Some philosophies also clash with religion, and oppose religious beliefs. For example, philosophies such as some existentialist views say that there is no meaning to life or human existence, except the meaning that we make up or invent. Most religions disagree with this belief.
Many major sciences, including physics, biology, psychology, and chemistry, were once considered a part of philosophy. As facts about nature became more understood, these subjects separated into their own fields. In modern times, subjects such as consciousness, decision theory, and applied ethics have found independence from philosophy. It can be argued that philosophy helped promote the development of these sciences, and that it has historically been an important field of study.
 Purpose 
A Philosopher asks questions about ideas, and tries to find answers to those questions. A philosopher also analyzes concepts, arguments, and problems in philosophy.
Some are academics that work for universities or colleges. These philosophers may write books and articles about philosophy and teach classes about the subject to university or college students.
Some are also monks, artists, or scientists. They also think about philosophical ideas and questions.
Philosophers often use both real and imaginary examples to make a point. For example, they may write about a real or fictional person in order to show what they think a good person or a bad person is like.
Some philosophers look for the simplest way to answer a question and say that is probably the right answer. This is a process called Occam's razor. Others believe that complicated answers to questions can also be right. For an example of a philosophical problem, see the God paradox.
Philosophers use logic to solve problems and answer questions. Logical consistency is a cornerstone of any acceptable theory. Philosophers who disagree with a theory will often try to find a logical contradiction in a theory. If they find a contradiction, this gives them a reason to reject that theory. If they do not find an inconsistency, the philosopher might show that the theory leads to a conclusion which is either unacceptable or ridiculous. This second approach is called reductio ad absurdum.
 Famous philosophers 
People listed here should be genuine philosophers, rather than social or political campaigners. The lists are not meant to be complete.
 The ancient Greek philosophers 
 Heraclitus
Socrates
Plato
Aristotle
Epicurus
Diogenes
 Later European/Western philosophers 
 Saint Augustine
 Saint Thomas Aquinas
 Duns Scotus
 Bonaventure
 William of Ockham
 George Berkeley
 Auguste Comte
 René Descartes
 Ralph Waldo Emerson
 Georg Wilhelm Frederich Hegel
 Thomas Hobbes
 David Hume
 Immanuel Kant
 Søren Kierkegaard
 Gottfried Wilhelm Leibniz
 John Locke
 Niccolò Machiavelli
 John Stuart Mill
 Jean-Jacques Rousseau
 Arthur Schopenhauer
 Baruch Spinoza
 William Whewell
 Friedrich Nietzsche
 Modern European and American philosophers 
 Louis Althusser
 G. E. M. Anscombe
 Simone de Beauvoir
 David Chalmers
John Dewey
Christian DeQuincey
 Martin Heidegger
 Karl Popper
 John Rawls
 Bertrand Russell
 Jean-Paul Sartre
 Ludwig Wittgenstein
 Albert Camus
 Latin American and Latina/o philosophers 
 Gloria E. Anzaldúa 
 Giannina Braschi 
 Sor Juana Inez de la Cruz 
 Maria Lugones 
 Ofelia Schutte
Eugenio María de Hostos
 Asian/Eastern philosophers 
 Avicenna
 Osho
 Confucius
 Siddhārta Gautama (the Gautama Buddha)
 Omar Khayyám
 Nanak
 Chuang Tzu
 Lao Tzu
 Sohrevardi
 Allama Iqbal
 Sun Tzu
 Adi Sankarachrya


2004: 2004
2004 (MMIV) was a leap year starting on Thursday in the Gregorian calendar.
 Events 
January
January 1 - Deiss becomes President of the Confederation in Switzerland.
January 2 - Several British Airways flights from London Heathrow Airport to Washington D.C. and Riyadh, Saudi Arabia are cancelled due to security fears.
January 3 - Flash Airlines Flight 604 crashes into the Red Sea off the coast of Egypt. All 148 aboard are killed.
January 3 - NASA's MER-A (Spirit) lands on Mars.
January 3 - Tony Blair goes to Basra, Iraq and talks to the British soldiers there. Very few people are told before he comes.
January 4 - Dr. Mikhail Saakashvili wins presidential elections in the Republic of Georgia.
  January 4 - A NASA rover lands on Mars and starts sending back photos of Mars.
January 5 - Britney Spears's marriage to childhood sweetheart Jason Allen Alexander is annulled (declared invalid) by a Las Vegas court after a surprise 55-hour marriage.
 January 5 - China confirms that a sick man in southern China has the SARS virus.
January 6 - An official look into the death of Diana, Princess of Wales begins in London. It is held by Michael Burgess, the coroner of The Queen's household.
January 12 - More than 100,000 people come together in Tel Aviv against Prime Minister Ariel Sharon's plan to withdraw from parts of Gaza and the West Bank.
January 13 - An Uzbekistan Airways plane crashes in Uzbekistan's capital of Tashkent. 37 are killed.
January 14 - The shock site Goatse.cx is placed on registry lock for violating the AUP.
January 15 - The South Korean Foreign Minister, Yoon Young-kwan resigns after he says he supports American policy towards North Korea.
January 20 - India signs a $1.5 billion deal with Russia to buy the 45,000 tonne aircraft carrier Admiral Gorshkov along with 28 MiG-29k fighter planes.
January 22 - The European Union bans the import of poultry from Thailand, as bird flu spreads throughout Southeast Asia.
January 24 - NASA's MER-B (Opportunity) lands on Mars.
January 28 - The findings of the Hutton Inquiry are published in London. The British Government is found not to have falsified information in the "sexed up dossier". The report criticises the BBC's role in the death of David Kelly, a weapons expert on Iraq.
January 28 - At a hearing of the Commission on Terrorist Attacks Upon the United States, it is revealed that the September 11, 2001 terrorists used mace (a brand of tear gas) or pepper spray to overpower the flight crew of American Airlines Flight 11.
January 31 - Mystery Science Theatre 3000 ends its run on the Sci-Fi Channel.
February
February 1 - A Hajj stampede in Mina, Saudi Arabia kills 251 pilgrims.
February 2 - An apartment building falls apart in Konya, Turkey, killing 92.
February 3 - The CIA admits that there was no immediate threat from weapons of mass destruction before the 2003 invasion of Iraq.
February 4 - Facebook is launched.
February 6 - A suicide bomber kills 41 people on a subway train in Moscow.
February 7 - His Royal Highness Charles, Prince of Wales begins a tour of the Middle East, visiting troops in Iraq, the Iranian earthquake zone at Bam and Saudi Arabia.
February 10 - At least 50 people are killed in a car bomb attack at a center for hiring police officers south of Baghdad.
February 10 - The French National Assembly votes to pass a law banning religious items and clothing from schools.
February 11 - Up to 47 people are killed in a car bomb attack on an army recruiting center in Baghdad.
February 12 - Same sex marriage in the United States: The City and County of San Francisco begins giving out marriage licenses to homosexual couples as an act of civil disobedience.
February 13 - Scientists in South Korea announce the cloning of 30 human embryos.
February 17 - 90482 Orcus is discovered (found)
February 18 - A train carrying gas, fertiliser and sulphur derails and explodes in Iran, killing 320 people.
February 20 - Iranian parliament election is held. Many reformist candidates are not allowed to run, resulting in a win by conservatives.
February 22 - A suicide bomber kills eight bus passengers in Jerusalem.
February 22 - Rebels capture Haiti's second-largest city, Cap-Haïtien.
February 24 - An earthquake in Morocco kills 571 people.
February 26 - Former British cabinet minister, Clare Short reveals that British Intelligence bugged the phone calls of United Nations officials, including Kofi Annan.
February 26 - The United States lifts a ban on travel to Libya, ending travel restrictions that had lasted for 23 years.
February 29 - 2004 Haiti Rebellion: Jean-Bertrand Aristide resigns as president of Haiti. The chief justice of the Haitian Supreme Court, Boniface Alexandre, is sworn in as interim (short-term) president. Aristide later says he was made to resign, and that he was taken from the country by American soldiers.
March
March 1 - Prime Minister Ahmed Qurie blasted ongoing Israeli extrajudicial executions of Palestinian activists, which claimed two more lives on Sunday, and blamed Israel for the weekend of violence, whilst accusing his Israeli counterpart’s government of trying "to kill any possibility for (achieving a) mutual cease-fire".
March 1 - Jean-Bertrand Aristide claims that his resignation as President of Haiti was forced and that he was kidnapped by American forces and forced to leave the country against his will. United States Vice President Dick Cheney rejects the accusation.
March 1 - President of Russia Vladimir Putin names Mikhail Fradkov as his new prime minister.
March 1 - Several hundred United States, French and Canadian troops are sent to Haiti.
March 2 - The Palestinian Authority's prisoners' affairs ministry states in its monthly statistical report that the number of Palestinian prisoners has risen to around 7,500. Of those 336 are children, 75 are female, and 943 are in need of medical treatment. Of the 166 prisoners who died, 41% died as a result of medical negligence, while 18% died as a result of torture.
March 2 - Israel's Central Bureau of Statistics reports 1,850 new housing units in the Jewish settlements Israel built in the West Bank and Gaza Strip in 2003, up by 35 percent from the previous year.
March 2 - John Kerry wins the Super Tuesday primaries in California, Connecticut, Georgia, Maryland, Massachusetts, New York, Ohio, and Rhode Island, and the caucus in Minnesota, effectively winning the nomination. Howard Dean wins in his home state of Vermont even though he is no longer actively campaigning. John Edwards is reported to be withdrawing from the race three hours before polls close in California and just as the caucuses begin in Minnesota.
March 2 - Jason West, mayor of New Paltz, New York is charged with 19 criminal counts of performing marriages without a license. If convicted, he faces up to a $500 fine and a year in jail on each count.
March 2 - Exploration of Mars: NASA announces that Mars rover Opportunity landed in an area where "liquid water once drenched the surface".
March 2 - Bernard Ebbers, ex-CEO of Worldcom, is indicted on three counts of conspiracy for his alleged role in that company's $11 billion accounting scandal in 2002. Worldcom's CFO Scott Sullivan pleads guilty and is expected to cooperate with prosecutors against Ebbers.
March 2 - Multiple explosions hit Shiite shrines in Baghdad and Karbala on the Shia festival of Ashura. Over 180 people are reported killed. A three-day long period of national mourning is announced.
March 2 - Iraq gets a Bill of Rights, including guarantees of freedom of religion and press, in the form of the Law of Administering the Iraqi State for the Transitional Period.
March 2 - The U.S. declares its 2,000-man force to have leadership over all foreign military forces in Haiti. President Bush chose not to wait for the UN Security Council but, instead, to intervene immediately to "restore order" in the western hemisphere's poorest country.
March 2 - The European Union imposes additional 5% tariffs on a wide range of goods imported from the United States, such as honey, paper, and nuclear reactors. The tariffs were sanctioned by the World Trade Organization in 2002 as punitive measures after a ruling declaring that United States tax law unfairly favors U.S.-based companies.
March 2 - The European Space Agency's Rosetta space probe is successfully launched aboard an Ariane 5 rocket on a mission to investigate the comet 67P/Churyumov-Gerasimenko.
March 3 - At the Walt Disney Company's Annual General Meeting, about 43% of Walt Disney stockholders, including several prominent pension funds, vote to oppose the re-election of chairman and CEO Michael Eisner. The board of directors replaces him as chairman with George J. Mitchell.
March 3 - Researchers at Harvard University announce that they will give scientists free access to 17 human embryonic stem cell lines created without U.S. federal funding. This move is expected to help stem cell research in the face of federal funding restrictions announced in 2001 by the Bush administration.
March 3 - A new government of Serbia, headed by Vojislav Kostunica, is approved by parliament.
March 3 - March 3 - Israeli aircraft destroy a car in the Gaza strip with missile fire, killing three people acknowledged by Palestinian officials as members of the militant group Hamas.
March 3 - March 3 - A group of Israelis join a court challenge against the Israeli West Bank barrier out of concern it could turn their good Palestinian neighbors into deadly enemies.
March 3 - New claims of bubble fusion are made, claiming that the results of previous experiments have been replicated under more stringent experimental conditions.
March 4 - Bomb blasts in Iraq threaten to de-stabilise the country.
March 4 - The guilty verdict for Moroccan al-Qaeda suspect Mounir el Motassadeq's involvement in the September 11, 2001 attacks is overturned by the German appeals court, which orders a retrial.
March 4 - Three American Muslims accused of using paintball games to train for a jihad holy war are found guilty of conspiracy charges.
March 4 - Chinese authorities release Wang Youcai, a day after Rabiya Kadeer's release 
March 4 - Israeli tanks around 15 armoured vehicles escorted by several bulldozers enter the town of Rafah in the southern Gaza Strip, exchanging gunfire with resistance and later demolishing a four-storey building, claiming "anti-terrorist operations".May 2022
March 4 - The Prime Minister of Malaysia dissolves the national parliament and all state assemblies except Sarawak's, paving the way for the general election to be held within 60 days as dictated by the constitution.
March 5 - CBS broadcasts tape recordings of Diana, Princess of Wales as she describes suicide attempts while pregnant with Prince William, Duke of Cambridge.
March 5 - The National People's Congress convenes in Beijing. Premier Wen Jiabao makes his first state address, saying that "solving the problems of agriculture, villages and farmers is one of the most crucial parts of our entire work".
March 5 - Last minute disagreement delays signing of Iraq's interim constitution.
March 5 - The Russian polar station will be evacuated. Russia launches rescue operation to evacuate 12 of its scientists stranded on a research station which partially sank near the North Pole.
March 5 - Tony Blair defends the war in Iraq, stating that "global threat we face in Britain and round the world is real and existential and it is the task of leadership to expose it and fight it, whatever the political cost." 
March 5 - Police hold a Haifa man, Eliran Golan, and his 54-year-old father in custody on suspicion of involvement in making and planting bombs over the last three years. Haifa Magistrate court extends for five days the remand of Yivgeny Grossman. Grossman denies any connection.
March 5 - Martha Stewart is found guilty by a jury on charges of conspiracy, obstruction of justice, and two counts of making false statements regarding alleged insider trading in December 2001. She faces up to 20 years in prison, though it is considered unlikely that she would be sentenced to that maximum. Sentencing is set for June 17.
March 5 - Nunavut general election, 2004: the new legislature returns Paul Okalik to office as Premier of Nunavut, the largest territory of Canada.
March 5 - Key Tokyo stock indexes Nikkei 225 and Topix hit 21-month highs.
March 5 - The trial of former Prime Minister of Finland Anneli Jäätteenmäki ends. She has been accused of leaking secret foreign ministry documents referring to her predecessor Paavo Lipponen's meetings with George W. Bush.
March 6 - Tens of thousands demonstrate in Caracas, Venezuela, against what they see as the government's fraud committed by the Consejo Nacional Electoral related to the realization of a presidential referendum in mid-2004.
March 6 - The United States puts forth a UN Security Council resolution seeking to freeze the assets of Charles Taylor, the exiled former President of Liberia. The U.S. also announces that it is pledging $35 million to help rebuild Liberia's armed forces and that it supports the cancellation of Liberia's international debt, providing that economic reforms are implemented.
March 6 - Palestinians are killed and wounded in attack on the main crossing point between the Gaza Strip and Israel. Hamas, Islamic Jihad, and the al-Aqsa Martyrs Brigades claim responsibility.
March 6 - Up to 80,000 people march through the Turkish capital Ankara against plans to reform the country's civil service. The marchers fear that the reforms could lead to the civil service becoming politicised or losing its secular status.
March 6 - The scientists of the Russian polar research station near the North Pole are evacuated from their shifting and cracking ice floe by two Russian helicopters via Norway's Spitzbergen island.
March 7 - The New York City medical examiner reveals that a body pulled from the East River is that of actor/writer Spalding Gray, who had been missing since January.
March 7 - Greek legislative election, 2004: New Democracy, led by Costas Karamanlis, wins over the Panhellenic Socialist Movement, led by George Papandreou.
March 7 - An explosion rocks a Moscow apartment block. Initial reports from police suggest that the explosion was caused by a bomb, in spite of increased security before the presidential election on March 14. Later reports state that the explosion was due to a gas leak.
March 7 - The White House reports that all of Libya's remaining nuclear weapons-related equipment has been sent to the United States.
March 7 - Palestinian sources say that 14 people died after an Israeli raid into the refugee camps of al-Bureij and Nusseirat. Israeli sources say it was a "pinpoint" operation against the "terrorist infrastructure".
March 7 - The 2004 Formula One championship gets under way with the Australian Grand Prix in Melbourne. Michael Schumacher wins.
March 7 - In Sweden some 15,500 skiers compete in the 80th installment of Vasaloppet, the oldest and longest cross-country ski race in the world. Norwegian Anders Aukland wins.
March 7 - In Austria there are elections in the states of Salzburg and Carinthia. In Salzburg, the SPÖ earns a majority for the first time. In Carinthia, the election is an unexpected success for Jörg Haider FPÖ.
March 7 - It is announced that Peter Maxwell Davies is to be the United Kingdom's next Master of the Queen's Music.
March 7 - The headquarters of the United States-led coalition in Baghdad come under rocket attack from Iraqi guerillas, the day before the new Iraqi temporary constitution is due to be signed.
March 8 - Dr. Jiang Yanyong, who exposed the SARS coverup in the People's Republic of China, sends a letter to the National People's Congress calling the forceful suppression of the Tiananmen Square protests of 1989 a "mistake." 
March 8 - Iraq's governing council unanimously approves the country's new constitution.
March 8 - On International Women's Day, Afghan President Hamid Karzai encourages men to allow their female relatives to vote in the upcoming election, but also suggests that they control those votes.
March 9 - March 9, 2004 attack of Istanbul restaurant in Turkey by two Islamic suicide bombers killing one, injuring five.
March 9 - New hubble Space Telescope images show deepest view of the universe yet.
March 9 - John Allen Muhammad is sentenced to death by a Virginia judge because he was part of the Beltway sniper attacks.
March 9 - A genetically modified crop, Bayer's Chardon LL maize, is approved for growing in England for animal feed from 2005 until October 2006. The Scottish Executive also approves the move, but asks Scottish farmers to hold off. MPs and farmers protest in anger as the science is questioned. The Welsh National Assembly's Environment Minister announces he is still opposed to approving the crop.
March 9 - Pakistan announces a successful first flight test of its Hatf VI / Shaheen II long-range nuclear-capable ballistic missile. The missile has a range of 2,000 km 1,250 mi and can carry a payload of 1,000 kg 2,200 lb.
March 9 - Five of the nine Britons held by American authorities at Guantanamo Bay under suspicion of having links to terrorist organisations are returned to Britain. They are to be questioned by British anti-terrorism police on arrival.
March 9 - The FBI arrests William Cottrell, a Caltech student and alleged member of the Earth Liberation Front, in connection with last summer's spate of arson attacks at a car dealerships which destroyed or damaged over one hundred vehicles, including many Hummer H2 luxury SUVs.
March 10 - Five British men released from detention at Camp Delta, Guantanamo Bay land at RAF Brize Norton. Four are immediately arrested by the Metropolitan Police and taken to Paddington Green high security police station in Central London for questioning.
March 10 - Lee Boyd Malvo is sentenced to life in prison without parole by a Virginia judge for his role in the Beltway Sniper Attacks.
March 11 - The Spirit rover takes first picture of Earth ever made from the surface of another planet.
March 11 - March 11, 2004 Madrid attacks: 10 bombs on Madrid commuter trains kill at least 180 people and hurt more than 1400, the most people ever hurt in any bombing in Europe the 1988 Lockerbie bombing killed more but wounded fewer.
March 11 - Four British prisoners who had been arrested on their return from Guantanamo Bay are released without charge. A fifth was not arrested on arrival. A further four remain in the Cuban camp. British newspapers vie for the rights to their stories, with offers in the range of £300,000. These five people are expected to sue the United States and UK governments.
March 11 - Same-sex marriage in the United States: The California Supreme Court issues an rule ordering San Francisco officials to stop issuing marriage licenses to same-sex couples. The court said it would hear oral arguments regarding the controversy in May or June. The state says it did not register any of the thousands of recent gay marriages.
March 11 - UN inspectors find weapons-grade uranium in Iran. Iran objects to UN and United States policy, considering it "unrealistic." 
March 11 - A Maryland woman and former Democratic congressional aide, Susan Lindauer, is arrested on charges of conspiracy against the United States, acting as an Iraqi spy before and during last year's invasion.
March 11 - An Australian Senate report on poverty is immediately dismissed by Prime Minister John Howard. The report shows between 2 and 3.5 million Australians, or up to 19 per cent of the population, are living in poverty.
March 12 - A Utah woman is charged with murder when her child is stillborn because she did not want to have a Caesarean section.
March 12 - Millions of people pack rainy streets across Spain in protest against the recent Madrid bombings.
March 12 - The parliament of South Korea votes to impeach President Roh Moo-hyun, saying he "breached election rules" by calling for support for the Uri party. Prime Minister Goh Kun will run the country until the Constitutional Court rules on the issue. Roh's supporters dismiss the move as a power play to influence the upcoming April elections. Thousands protest in support of Roh.
March 12 - Guantanamo Bay: Recently released British Camp X-Ray inmate Jamal al-Harith is interviewed by the Daily Mirror, alleging physical assaults and psychological torture.
March 13- His Royal Highness The Duke of Gloucester and the Spanish Ambassador to the United Kingdom attend the Changing of the Guard ceremony at Buckingham Palace where the Spanish national anthem is played to honour the victims of the Madrid train bombings. The death toll in the bombings rises to 200; investigators continue search for perpetrators, with suspicions against ETA complemented by the apprehension of five foreign citizens connected to terror attacks in Morocco.
March 13 - Fifteen teams that qualified for the DARPA Grand Challenge start on a 150–200 mile robotic race to Las Vegas, Nevada, for a $1 million prize. All of the teams break down within seven miles of the start line; none collect the prize.
March 13 - Nine people, including eight children, are found dead in Fresno, California. One of their family members is arrested for the deaths. The police speculate that the deaths may have been part of a ritual.
March 14 - The Spanish parliamentary elections of 2004 take place. The incumbent government led by Jose Maria Aznar is defeated by the Socialist José Luis Rodríguez Zapatero.
March 14 - Two suicide bombers kill 10 people in Ashdod, Israel.
March 14 - Madrid bombings: Spanish police receives a videotape where a man identifying himself as an al-Qaeda spokesman says the organisation claims responsibility for the attack, according to an announcement from the country's interior minister. The authenticity of the video has not been verified. The al-Qaeda claim overshadows voting in the general election.
March 14 - Occupation of Iraq: Six United States soldiers are killed over the weekend in three separate insurgent roadside bomb attacks, two in Baghdad and one in Tikrit. This occurs amidst the largest U.S. troop rotation since World War II.
March 14 - The people of Russia have a presidential election. Current president Vladimir Putin wins by a lot of votes. The election is widely criticised by external observers who said Russian state television was very biased towards Putin during the campaign.
March 14 - Pope John Paul II becomes the third-longest reigning pope in history, the other two being Saint Peter and Pope Pius IX.
March 14 - Several Kurds storm the Syrian embassy in Brussels protesting about violence and deaths in north-east Syria over the weekend.
March 14 - Presidential elections in Russia are held. Vladimir Putin easily wins a second term.
March 15 - Four U.S. Baptist missionaries working on a water purification project are killed in a drive-by shooting in the northern Iraqi city of Mosul.
March 15 - The city of Aliso Viejo, California, nearly bans foam cups when they learn they are produced from a substance known as Dihydrogen monoxide (water), a substance that could "threaten human health and safety." 
March 15 - Pavlo Lazarenko, former prime minister of Ukraine, stands trial in a U.S. federal court in San Francisco for money laundering.
March 15 - Same-sex marriage in the United States: Commissioners of Multnomah County, Oregon dismiss state attorney general Hardy Myers' non-binding opinion that same-sex marriages are illegal and vow to continue issuing marriage licenses to same-sex couples.
March 15 - Newly elected Spanish Prime Minister José Luis Rodríguez Zapatero announces his government's opposition to the invasion and continued occupation of Iraq and his intention to withdraw Spanish troops from Iraq by June 30, unless they are part of a U.N. force.
March 15 - Astronomers announce the discovery of Sedna, a Pluto-like planetoid which is the most distant individual object known to orbit the Sun.
March 15 - Exiled Syrian Kurds storm the Syrian consulate in Geneva and other Kurds protest in Turkey and Germany at weekend violence in northeast Syria.
March 16 - Spanish police identify six Moroccans suspected to have carried out the March 11 Madrid attacks. Five of the suspects are still at large but one is in custody.
March 16 - An explosion at an apartment building in Arkhangelsk, Russia, kills 32.
March 16 - The Federal Reserve votes to keep interest rates the same, primarily since there are not many new jobs in the United States.
March 17 - Unrest in Kosovo: After two Albanian children are found drowned in the Ibar river in Kosovo and Metohia, with a third still missing, riots erupt in the town of Kosovska Mitrovica and later spread to the entire province. Mitrovica Serbs are blamed by Albanian media for forcing the children into the river, but this is later denied by United Nations officials. At least 22 people are killed by the end of the day with hundreds injured in clashes between Serbs and Albanians; enclaves of Kosovo Serbs elsewhere in the province experience attacks by Kosovo Albanians as well as offices of UN officials which were abandoned. In reaction to the violence in Kosovo, demonstrators in Serbia march in Belgrade and set ablaze mosques in Belgrade and Nish.
March 17 - Occupation of Iraq: A car bomb flattens the Mount Lebanon Hotel in central Baghdad, killing at least 17 people and hurting 45 more people.
March 17 - Utah bans execution by firing squad.
March 18 - Howard Dean announces plans to form Democracy for America, a political organization intended to help progressive candidates holding similar views.
March 18 - Unrest in Kosovo: The North Atlantic Treaty Organisation (NATO) announces that it will reinforce its Kosovo peacekeeping force, following ethnic fighting there that has killed at least 31 people over the past two days. More Serbian Orthodox Churches have been set on fire by Albanians and violence has continued in and around Kosovo Serb enclaves. Russia and Serbia-Montenegro call for an urgent meeting of the UN Security Council. United Nations officials attempt to restore order in the province and blame the unrest on nationalist extremists on both sides. More demonstrations have taken place across Serbia, so far without the violence seen the previous day.
March 18 - Near-Earth asteroid 2004 FH is making the closest approach of an asteroid ever recorded. At 22:08 UTC it will pass 43,000 km above Earth's surface.
March 18 - Cleanup work at Love Canal has been completed, federal officials said. The EPA says it should be taken off the Superfund list.
March 18 - The United States House of Representatives all agree to double the reward for Osama bin Laden's capture to US$50 million.
March 19 - ICANN announces that a Toronto, Canada organization, the International Foundation for Online Responsibility (IFFOR), has applied to sponsor the .xxx top-level domain. IFFOR claims that a special domain would help stop children from seeing pornography. However, in February the Internet Engineering Task Force released RFC 3675, ".sex Considered Dangerous", detailing technical and administrative concerns with such proposals.
March 19 - The U.S. military drops all charges of alleged mishandling of classified information against Muslim Army chaplain Yousef Yee at Guantanamo Bay.
March 19 - Same-sex marriage in Canada: The Quebec Court of Appeal upholds a Quebec superior court ruling that same-sex marriages are valid under Canada's Charter of Rights and Freedoms. It joins Ontario and British Columbia in permitting same-sex marriage. The couple which brought the suit is scheduled to be wed on April 10, after a required 20-day waiting period.
March 19 - Äänekoski bus disaster: At least 24 young people are killed and 15 hurt, several of them seriously, in a collision on an icy road between a coach and a lorry carrying rolls of paper on Highway 4 near Äänekoski in Central Finland. The accident happened at around 2 a.m. local time (UTC +2).
March 19 - The newspaper USA Today admits that a former reporter, Jack Kelley, invented or distorted important parts of at least eight major stories. He was, for example, a finalist for the Pulitzer Prize in 2001 on the basis of an eyewitness account of a suicide bombing that, could not have happened as he described it.
March 20 - ROC presidential election: Chen Shui-bian is declared the winner over Lien Chan by fewer than 30,000 votes of nearly 13,000,000 cast (0.25%). Lien calls the result unfair and demands it be voided. A controversial referendum is invalidated by low turnout.
March 20 - Former Queen Juliana of the Netherlands dies aged 94.
March 20 - On the first anniversary of the 2003 invasion of Iraq, millions join protests in cities across the world to demonstrate against the war and the continued occupation. In London two Greenpeace protesters evade newly tightened security and scale the Houses of Parliament's Clock Tower to unfurl a banner calling for the truth to be told by the UK government.
March 20 - Stephen Harper is elected as leader of the Conservative Party of Canada, winning 56% of the possible points on the first ballot.
March 20 - A Methodist church jury in Bothell, Washington acquits a lesbian minister of violation of church rules.
March 21 - Malaysian general election: Secular ruling coalition Barisan Nasional wins a two-thirds majority and wrests back the state of Terengganu from Islamist party PAS. A recount is pending for the closely contested state of Kelantan.
March 21 - Measurements taken at Mauna Loa Observatory show carbon dioxide readings of 379 parts per million, up by 3 ppm in one year; average increase for the past decade has been 1.8 ppm. The reason for this accelerated buildup in a greenhouse gas requires further analysis.
March 21 - Al-Qaeda claims to have purchased "smart briefcase bombs" with nuclear capabilities on the black market.
March 21 - Salvadoran presidential election: Voting takes place to elect a new president of El Salvador.
March 21 - ROC presidential election: Taiwan's High Court has ordered all ballot boxes to be sealed, in order to preserve evidence. However, a recount of votes was not ordered. Various protests are held throughout the island.
March 22 - Palestinians protest in the streets after an Israeli helicopter gunship fires a missile at the entourage of Sheikh Ahmed Yassin in Gaza City, killing Yassin and 7 others.
March 22 - ROC presidential election, 2004: Chen Shui-bian's Democratic Progressive Party submits a bill to the Legislative Yuan to allow an immediate recount, per Lien Chan's demand, but the majority Pan-Blue Coalition says it is not necessary, because the President could issue an executive order instead.
March 22 - Salvadoran presidential election: Tony Saca of the Nationalist Republican Alliance (ARENA) declares victory over a former Communist Party guerrilla leader, with 60% of the votes.
March 22 - Israel assassinates Sheikh Ahmed Yassin, the spiritual head of Hamas, in the Gaza Strip. It then seals off both the West Bank and the Gaza Strip. Kofi Annan, and the British, French, and German governments, amongst others, condemn the killing.
March 22 - The former chief counter-terrorism aide to United States President Bush, Richard A. Clarke, claims that Bush diverted attention towards Iraq, ignoring the main threat of Al-Qaeda. Clarke was the administration's senior counter-terrorism official when 9/11 took place.
March 22 - Mijailo Mijailovic is sentenced to life imprisonment for the equivalent of First-degree murder, found guilty of assassination of Sweden's Foreign Minister Anna Lindh, September 10, 2003.
March 22 - Same-sex marriage in the U.S.: Benton County, Oregon commissioners, after receiving a letter from state attorney general Hardy Myers, reverse their earlier vote to begin issuing marriage licenses to same-sex couples this Wednesday. But, stating they will observe the principal of equal treatment under the law, the commissioners decide that the county will stop issuing any marriage licenses until the Oregon Supreme Court has ruled on the constitutionality of the law.
March 23 - Unrest in Kosovo: an UNMIK police patrol is attacked on the road Pristina-Podujevo. A UN police officer from Ghana is killed, a local police officer later dies of his wounds, and their translator is also wounded but in stable condition.
March 23 - United States Secretary of Defense Donald Rumsfeld and Secretary of State Colin Powell defend their pre-September 11th actions, saying that even if Osama Bin Laden had been killed, the attacks on the World Trade Center and The Pentagon would have still happened. Former Secretary of State Madeleine Albright and former Secretary of Defense William Cohen also testify before the National Commission on Terrorist Attacks Upon the United States.
March 23 - Abdel Aziz al-Rantissi is chosen to lead Hamas in the Gaza Strip, and the movement's exiled politburo chief Khaled Meshaal is chosen as its overall leader.
March 24 - The World Trade Organization makes a preliminary ruling that United States laws prohibiting Internet gambling violate international trade agreements, in response to a complaint by Antigua and Barbuda. The Bush administration vows to appeal, while some members of the United States Congress say they would rather allow a trade war or withdraw from future WTO talks than undo laws against online gambling.
March 24 - Danish artist Marco Evaristti paints an iceberg in Greenland red, using 780 gallons of paint.
March 24 - Elk Grove Unified School District v. Newdow: The United States Supreme Court hears oral arguments over the constitutionality of the "under God" clause of the Pledge of Allegiance.
March 24 - The British explorer David Hempleman-Adams sets an altitude record for a flight in a wicker basket balloon.
March 24 - The leader of Hamas states that the group has no plans to attack United States targets, retreating from earlier threats by its armed wing. However, Israeli Prime Minister Ariel Sharon is announced as a new target, instead.
March 24 - Sharon states that Israel has a "natural right" to pursue those who would destroy it.
March 24 - Hussam Abdo, a 14-year-old Palestinian suicide bomber fails to detonate his bomb-vest at an Israeli checkpoint outside Nablus. The child was paid $23 and promised sex in heaven as his reward. An armed wing of Fatah takes responsibility for sending the boy.
March 25 - The 2004 Abel Prize in mathematics is announced to be awarded to Michael F. Atiyah and Isadore M. Singer for their index theorem.
March 25 - The terrorist group AZF suspends its bombing campaign in France but continues to demand money from the government. News agencies report that the government placed notices in Libération newspaper to contact the terrorists.
March 25 - Novelist and movie maker Alain Robbe-Grillet is elected to the Académie française.
March 25 - Five planets (Mercury, Venus, Mars, Jupiter, and Saturn) array across the evening sky in a night show that will not happen again for another three decades.
March 25 - A prototype of a mechanized five-ton disaster-rescue robot, the T-52 Enryu, is unveiled in Japan.
March 26 - United Nations electoral expert and security support arrive in Baghdad.
March 26 - The first South Atlantic hurricane ever recorded forms 275 miles off the coast of Brazil.
March 26 - ROC presidential election, 2004: The controversial victory of Chen Shui-bian is confirmed by the state electoral commission, with a margin of only 29,518 votes – 0.2% of the total – separating the candidates. Pan-Blue protestors storm and hurl eggs at the Central Electoral Commission building.
March 26 - Israeli-Palestinian conflict: The United States vetoes a United Nations Security Council resolution (sponsored by Algeria and Libya) condemning the killing by Israel of Sheikh Ahmed Yassin along with six other Palestinians outside a mosque in Gaza City and calling for the end of executions. The veto is publicly motivated by the resolution making no mention of suicide bombings committed by Hamas and attributed to Yassin. 11 votes are recorded in favour, with three (United Kingdom, Germany, and Romania) abstaining and one (the United States) against.
March 27 - John F. Kerry joins other Democrats calling for National Security Advisor Condoleezza Rice to testify before the September 11 commission and states the White House should learn from President Franklin Delano Roosevelt's openness during an inquiry after Pearl Harbor.
March 27 - ROC presidential election, 2004: 500,000 Pan-Blue protesters take to the streets in Taipei to demand a recount.
March 27 - NASA succeeds in a second attempt to fly its X-43A experimental airplane from the Hyper-X project, attaining speeds in excess of Mach 7, the fastest ever air-breathing Hypersonic flight.
March 27 - A powerful cyclone hits the coast of southern Brazil. Brazilian and United States meteorologists disagree over whether Cyclone Catarina is a Hurricane, the first ever recorded in the South Atlantic.
March 28 - Abdel Aziz al-Rantissi, leader of Hamas, states that God has declared war on the United States.
March 28 - The University of Cambridge wins a controversial victory in the 150th Boat Race by 6 lengths, with a total time of 18:47 minutes.
March 28 - The Arab League summit is postponed. The meeting was put off indefinitely because people disagreed about ways to change things in the region, including democratization.
March 28 - Israeli State Attorney Edna Arbel recommends that Prime Minister Ariel Sharon be indicted for taking bribes.
March 28 - The French regional elections result in massive losses for the governing conservative parties and victories for socialist-green alliances in at least 20 of 22 regions, leading to Raffarin's resignation on March 30.
March 28 - A coup attempt in the Democratic Republic of the Congo fails.
March 29 - Dominica switches diplomatic recognition from the Republic of China to the People's Republic of China.
March 29 - An explosion occurs close to the main bazaar in Tashkent, Uzbekistan, killing two and injuring around twenty. Also in the capital, three police officers are shot dead. In the city of Bukhara, another explosion at a suspected terrorist bomb factory kills ten people. (Reuters) https://web.archive.org/web/20050408162832/http://www.reuters.com/newsArticle.jhtml?type=worldNews&storyID=4685593 2005-04-08 (BBC)
March 29 - The Republic of Ireland becomes the first country to ban smoking in all enclosed workplaces (including bars and restaurants). People who break this law risk a large fine.
March 29 - The North Atlantic Treaty Organisation (NATO) welcomes seven new members: Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia.
March 29 - Beauty company Dove is to use "real women" in advertising after a survey finds two-thirds of UK women feel depressed about their figures and have low body confidence as a result of beauty advertising.
March 29 - Scientists discover methane in the Martian atmosphere and believe it could mean there is life on the Red Planet.
March 30 - New Jersey physicist Greg Olsen pays $20 million to conduct environmental research for eight days aboard the International Space Station.
March 30 - Police in Uzbekistan raid a Hideout south of the capital, Tashkent. Fighting has caused 23 deaths in the area.
March 30 - The Philippines police stop a big bomb attack after arresting four members of the Muslim extremist Abu Sayyaf group.
March 30 - The White House allows Condoleezza Rice, the president's national security advisor, testify under oath about the September 11, 2001 terrorist attacks.
March 30 - Eight men are arrested after a series of raids in the UK under the Terrorism Act 2000. Half a ton of ammonium nitrate fertilizer was found during the raids.
March 31 - Nine Americans are killed during the war in Iraq.
March 31 - The International Court of Justice rules that the USA was wrong to sentence 51 Mexicans to death for murder and says their trials must be reviewed.
March 31 - A Canadian court rules that the Canadian Recording Industry Association did not prove that downloading music from the Internet breaks the rules of copyright.
April
April 2 - A bomb found on the Madrid to Seville train line is defused by Spanish police.
April 3 - A bomb explosion in a Madrid flat kills five suspected terrorists responsible for the Madrid train bombings on March 11, and a Spanish policeman.
April 5 - Her Majesty Queen Elizabeth II of the United Kingdom begins a state visit to France to celebrate the 100th anniversary of the Entente Cordiale
April 8 - Three Japanese citizens are taken Hostage in Iraq.
April 16 - India defeats Pakistan in their historic first cricket tour in 14 years.
April 17 - Israeli helicopters fire missiles at a convoy of vechiles in the Gaza Strip, killing the leader of Hamas, Abdel Aziz al-Rantissi
April 20 - Tony Blair announces that the UK will hold a referendum on the European constitution.
April 21 - Mordechai Vanunu is released from prison in Israel after an 18-year term for treason.
April 21 - The American TV network, CBS broadcasts pictures of Diana, Princess of Wales as she lay dying moments after the fatal car crash that killed her.
April 22 - Two trains carrying explosives and fuel collide in the North Korean town of Ryongchon, killing 161 people, injuring 1,300 and destroying thousands of homes.
April 22 - The last coal mine in France closes, ending nearly 300 years of coal mining.
April 24 - The christening of Lady Louise Windsor takes place at Windsor Castle.
April 25 - Greek Cypriots reject a United Nations plan to unite the island of Cyprus in a referendum.
May
May 1 - An enlargement of the European Union takes place, expanding the Union by 10 member-states: Poland, Lithuania, Latvia, Estonia, the Czech Republic, Slovakia, Slovenia, Hungary, Malta, and Cyprus.
May 2 - After 3 weeks of captivity, American contractor Thomas Hamill escapes from his captors in Iraq with just a gunshot wound to the arm and makes it to US Military personnel.
May 5 - Parliament grounds in New Zealand host 15,000 people protesting about the proposed law that would change the ownership of foreshore and seabed.
May 6 - The president of Georgia, Mikhail Saakashvili, announces that Adzharian leader Aslan Abashidze has left the country, ending a political crisis there.
May 6 - The final episode of Friends airs on NBC. Advertisers pay $2 million for 30 second ads.
May 9 - Chechen president Akhmad Kadyrov is killed by landmine placed under a VIP stage during a World War II memorial victory parade in Grozny, Chechnya.
May 10 - Canadian Sponsorship Scandal - The RCMP arrest Chuck Guite and Jean Brault in connection with the scandal.
May 10 - Final phase of elections to the Lok Sabha in India
May 10 - National election takes place in the Philippines for the presidency and almost all other elective positions.
May 11 - Explosion destroys a plastics factory in Glasgow, UK, killing nine people and injuring over a hundred.
May 11 - A bomb explodes in a crowded market in Iraq. It kills three people and wounds at least 23.
May 11 - Chechen President Akhmad Kadyrov is buried in his home village.
May 12 - An American civilian contractor in Iraq, Nick Berg, is shown being decapitated by a group with links to al-Qaida on a web-distributed video. They state it is retaliation for the abuse at Abu Ghraib prison.
May 12 - Semi final takes place in the Eurovision Song Contest 2004 in Turkey.
May 13 - In India, the Congress Party wins a shock victory in the elections to the Lok Sabha (lower house of Parliament).
May 13 - The season finale for Frasier is aired.
May 14 - The editor of the Daily Mirror newspaper in the UK, Piers Morgan, is sacked after the British army proves photographs in the newspaper, allegedly showing British soldiers abusing Iraqi detainees, to be fake.
May 14 - Danish Crown Prince Frederik has married Australian Mary Konadson in Copenhagen, Denmark.
May 15 - FIFA announces that South Africa will host the 2010 World Cup soccer tournament, making it the first African nation to do so.
May 20 - A 6.5-magnitude earthquake hits Taiwan. There is no immediate reports of damage or injuries.
June
June 5 - Former U.S. President Ronald Reagan dies of pneumonia at the age of 93.
June 11 - state funeral of former U.S. President Ronald Reagan is held.
June 12 - Former U.S. President Bush celebrates his 80th birthday by skydiving.
July
July 1 – The Cassini-Huygens spacecraft arrives at Saturn.
July 4 – Groundbreaking for the Freedom Tower begins at Ground Zero in New York City.
July 4 – In football, Greece wins the European Championships, after being rated as an 80-1 rank outsider.
August
August 13–August 29 – The 2004 Summer Olympics are held in Athens, Greece.
August 16 – The village of Boscastle in Cornwall is hit by a flash flood.
September
September 1 – Many schoolchildren are taken hostage at a school in Beslan, southern Russia. Many of them are massacred on September 3.
September 23 – Mount St. Helens becomes active again.
October
October 27 – The Boston Red Sox sweep the St. Louis Cardinals in four games to win the 2004 World Series. It is the Red Sox first World Series championship since 1918.
October 29 – King Norodom Sihanouk of Cambodia abdicates in favour of his son, Norodom Sihamoni.
November
November 2 – George W. Bush is reelected as President of the United States.
November 21 – The Orange Revolution begins in Ukraine.
December
December 26 - A strong earthquake from the Indian Ocean kills at least 140,000 people.
December 26 – In the wake of the Orange Revolution, Viktor Yushchenko is elected President of Ukraine.
December 31 – The Taipei 101 tower is opened in Taipei, Taiwan.
 Nobel prize winners 
 Chemistry – Aaron Ciechanover
 Chemistry – Avram Hershko
 Chemistry – Irwin Rose
 Economics – Finn E. Kydland
 Economics – Edward C. Prescott
 Literature – Elfriede Jelinek
 Medicine – Richard Axel
 Medicine – Linda B. Buck
 Peace – Wangari Maathai
 Physics – David J. Gross
 Physics – H. David Politzer
 Physics – Frank Wilczek


Physics: Physics is a branch of science. It is one of the most fundamental scientific disciplines. The main goal of physics is to explain how things move in space and time and understand how the universe behaves. It studies matter, forces and their effects.
The word physics comes from the Greek word ἡ φύσις, meaning "nature". Physics can also be defined as "that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events".
Physics is very important in engineering and developing new technologies, such as aviation, electronics and weapons. One reason for starting the mathematical field of calculus was to help develop mechanics, a branch of physics.
Modern physics connects ideas about the four laws of symmetry and conservation of energy, momentum, charge, and parity. 
Astronomy, now a part of physics, is the oldest natural science. In the past it was a part of 'natural philosophy' with other fields of science, such as chemistry and biology. During the scientific revolution, these fields became separate, and physics became a distinct field of knowledge.
 History 
 Ancient astronomy 
Astronomy is one of the oldest natural science. The Sumerians, and Ancient Egyptians studied the stars, mostly with a view to prediction and religion. The first Babylonian star maps date from about 1200 BC. That astronomical events are periodic also dates back to the Babylonians. Their understanding was not scientific, but their observations influenced later astronomy. Much astronomy came from Mesopotamia, Babylonia, Ancient Egypt, and Ancient Greece. Astronomers from Egypt built monuments that showed how objects in the sky moved, and most of the names for the constellations in the Northern hemisphere came from Greek astronomers.
 Natural philosophy 
Natural philosophy started in Greece around 650 BC when a movement of philosophers replaced superstition with naturalism, which refuted the spiritual. Leucippus and his student Democritus suggested the idea of the atom around this period.
 Physics in the medieval Islamic world 
Islamic scholars continued to study Aristotelian physics during the Islamic Golden Age. One main contribution was to observational astronomy. Some, like Ibn Sahl, Al-Kindi, Ibn al-Haytham, Al-Farisi and Avicenna, worked on optics and vision. In The Book of Optics, Ibn al-Haytham rejected previous Greek ideas concerning vision and proposed a new theory. He studied how light enters the eye, and developed the camera obscura. European scientists later built eyeglasses, magnifying glasses, telescopes, and cameras from this book.
 Classical physics 
Physics became a separate field of study after the scientific revolution. Galileo's experiments helped to create classical physics. Although he did not invent the telescope, he used it when he looked into the night sky. He supported Copernicus' idea that the Earth moved around the Sun (heliocentrism). He also investigated gravity. Isaac Newton used Galileo's ideas to create his three laws of motion and his law of universal gravitation. Together these laws explained the motion of falling bodies near the earth and the motion of earth and planets around the sun. 
In a couple centuries, the Industrial Revolution was in full swing and many more discoveries were made in many fields of science. The laws of classical physics are good enough to study objects that move much slower than the speed of light, and are not microscopic. When scientists first studied quantum mechanics, they had to create a new set of laws, which was the start of modern physics.
 Modern physics 
As scientists researched particles, they discovered what classical mechanics could not explain. Classical mechanics predicted that the speed of light varied, but experiments showed the speed of light stayed the same. This was predicted by Albert Einstein's theory of special relativity. Einstein predicted that the speed of electromagnetic radiation through empty space would always be the same. His view of space-time replaced the ancient idea that space and time were quite separate things.
Max Planck came up with quantum mechanics to explain why metal releases electrons when you shine a light at it, and why matter emits radiation. Quantum mechanics applies for very small things like the electrons, protons, and neutrons that make up an atom. People like Werner Heisenberg, Erwin Schrödinger, and Paul Dirac continued to work on quantum mechanics and eventually we got the Standard Model.
 Definition 
Physics is the study of energy and matter in space and time and how they are related to each other. Physicists assume the existence of mass, length, time and electric current and then define (give the meaning of) all other physical quantities in terms of these basic units. Mass, length, time, and electric current are never defined but the standard units used to measure them are always defined. In the International System of Units (abbreviated SI from the French Système International), the kilogram is the basic unit of mass, the metre is the basic unit of length, the second is the basic unit of time, and the ampere is the basic unit of electric current. In addition to these four units, there are three other ones: the mole, which is the unit of the quantity of matter, the candela which measures the luminous intensity (the power of lighting) and the kelvin, the unit of temperature.
Physics studies how things move, and the forces that make them move. For example, velocity and acceleration are used by physics to show how things move. Also, physicists study the forces of gravity, electricity, magnetism and the forces that hold things together.
Physics studies very large things, and very small things. For instance, physicists can study stars, planets and galaxies but could also study small pieces of matter, such as atoms and electrons.They may also study sound, light and other waves. As well as that, they could examine energy, heat and radioactivity, and even space and time. 
Physics not only helps people understand how objects move, but how they change form, how they make noise, how hot or cold they will be, and what they are made of at the smallest level. In short, physics is the branch of science that deals with properties of matter and energy along with the interaction between them.
 Physics and mathematics
Physics is a quantitative science because it is based on measuring with numbers. Mathematics is used in physics to make models that try to predict what will happen in nature. These predictions are compared to the way the real world works. Physicists are always working to make their models of the world better.
 Branches 
Classical mechanics contains major topics such as Newton's laws of motion, Lagrangian mechanics, Hamiltonian mechanics, kinematics, statics, dynamics, chaos theory, acoustics, fluid dynamics, continuum mechanics. Classical mechanics is all about forces acting on a body in nature, balancing forces, maintaining equilibrium state, etc. 
Electromagnetism is study of charges on a particular body. It contains subtopics such as Electrostatics, electrodynamics, electricity, magnetism, magnetostatics, Maxwell's equations, optics. 
Thermodynamics and statistical mechanics are related with temperature. It includes main topics such as Heat engine, kinetic theory. It uses terms such as heat(Q), work(W), and internal energy (U). First law of thermodynamics gives us the relation them by the following equation (ΔU = Q − W)
Quantum mechanics is the study of particle at the atomic level taking into consideration the atomic model. It includes subtopics Path integral formulation, scattering theory, Schrödinger equation, quantum field theory, quantum statistical mechanics.
 Relativity 
 Advanced knowledge 
 General description 
Physics is the science of matter and how matter interacts. Matter is any physical material in the universe. Everything is made of matter. Physics is used to describe the physical universe around us, and to predict how it will behave. 
Physics is the science concerned with the discovery and characterization of the universal laws which govern matter, movement and forces, and space and time, and other features of the natural world.
 Breadth and goals of physics 
The sweep of physics is broad, from the smallest components of matter and the forces that hold it together, to galaxies and even larger things. There are only four forces that appear to operate over this whole range. However, even these four forces (gravity, electromagnetism, the weak force associated with radioactivity, and the strong force which holds protons and neutrons in an atom together) are believed to be different parts of a single force.
Physics is mainly focused on the goal of making ever simpler, more general, and more accurate rules that define the character and behavior of matter and space itself. 
One of the major goals of physics is making theories that apply to everything in the universe. In other words, physics can be viewed as the study of those universal laws which define, at the most basic level possible, the behavior of the physical universe.
 Physics uses the scientific method 
Physics uses the scientific method. That is, data from experiments and observations are collected. Theories which attempt to explain these data are produced. Physics uses these theories to not only describe physical phenomena, but to model physical systems and predict how these physical systems will behave. Physicists then compare these predictions to observations or experimental evidence to show whether the theory is right or wrong.
The theories that are well supported by data and are especially simple and general are sometimes called scientific laws. Of course, all theories, including those known as laws, can be replaced by more accurate and more general laws, when a disagreement with data is found.
 Physics is quantitative 
Physics is more quantitative than most other sciences. That is, many of the observations in physics may be represented in the form of numerical measurements. Most of the theories in physics use mathematics to express their principles. Most of the predictions from these theories are numerical. This is because of the areas which physics has addressed work better with quantitative approaches than other areas. Sciences also tend to become more quantitative with time as they become more highly developed, and physics is one of the oldest sciences.
 Fields of physics 
Classical physics normally includes the fields of mechanics, optics, electricity, magnetism, acoustics and thermodynamics. Modern physics is a term normally used to cover fields which rely on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics, as well as the more modern fields of general and special relativity, but these last two are often considered fields of classical physics as they do not rely on quantum theory. Although this difference can be found in older writings, it is of little new interest as quantum effects are now understood to be of importance even in fields that before were called classical.
 Approaches in physics 
There are many ways to study physics, and many different kinds of activities in physics. The two main types of activities are the collection of data, and the development of theories.
Some subfields of physics can be studied by experiment. For example, Galileo Galilei invented kinematics by making experiments and studying the data. Experimental physics focuses mainly on an empirical approach. Some experiments are done to explore nature, and other experiments are performed to produce data to compare with the predictions of theories.
Some other fields in physics like astrophysics and geophysics are mostly observational sciences because most of their data has to be collected passively instead of through experimentation. Galileo, for example, could only look at Jupiter and discover that it has moons. However, observational programs in these fields use many of the same tools and technology that are used in the experimental subfields of physics. 
Theoretical physics often uses quantitative approaches to develop the theories that attempt to explain the data. In this way, theoretical physicists often use tools from mathematics. Theoretical physics often can involve creating quantitative predictions of physical theories, and comparing these predictions quantitatively with data. Theoretical physics sometimes creates models of physical systems before data is available to test and support these models.
These two main activities in physics, data collection, theory production and testing, use many different skills. This has led to a lot of specialization in physics, and the introduction, development and use of tools from other fields. For example, theoretical physicists use mathematics and numerical analysis and statistics and probability and computer software in their work. Experimental physicists develop instruments and techniques for collecting data, using engineering and computer technology and many other fields of technology. Often the tools from these other areas are not quite appropriate for the needs of physics, and need to be changed or more advanced versions have to be made.
It is frequent for new physics to be discovered if experimental physicists do an experiment that current theories cannot explain, or for theoretical physicists to generate theories which can then be put to the test by experimental physicists.
Experimental physics, engineering and technology are related. Experiments often need specialized tools such as particle accelerators, lasers, and important industrial applications such as transistors and magnetic resonance imaging have come from applied research.
 Physicists 
Prominent physicists
yes 20em
Galileo Galilei (1564–1642)
Christiaan Huygens (1629–1695)
Isaac Newton (1643–1727)
Leonhard Euler (1707–1783)
Joseph Louis Lagrange (1736–1813)
Pierre-Simon Laplace (1749–1827)
Joseph Fourier (1768–1830)
Nicolas Léonard Sadi Carnot (1796–1842)
William Rowan Hamilton (1805–1865)
Rudolf Clausius (1822–1888)
James Clerk Maxwell (1831–1879)
J. Willard Gibbs (1839–1903)
Ludwig Boltzmann (1844–1906)
Hendrik A. Lorentz (1853–1928)
Henri Poincaré (1854–1912)
Nikola Tesla (1856–1943)
Max Planck (1858–1947)
Albert Einstein (1879–1955)
Milutin Milanković (1879–1958)
Emmy Noether (1882–1935)
Max Born (1882–1970)
Niels Bohr (1885–1962)
Erwin Schrödinger (1887–1961)
Louis de Broglie (1892–1987)
Satyendra Nath Bose (1894–1974)
Wolfgang Pauli (1900–1958)
Enrico Fermi (1901–1954)
Werner Heisenberg (1901–1976)
Paul Dirac (1902–1984)
Eugene Wigner (1902–1995)
Robert Oppenheimer (1904–1967)
Sin-Itiro Tomonaga (1906–1979)
Hideki Yukawa (1907–1981)
John Bardeen (1908–1991)
Lev Landau (1908–1967)
Anatoly Vlasov (1908–1975)
Nikolay Bogolyubov (1909–1992)
Subrahmanyan Chandrasekhar (1910–1995)
John Archibald Wheeler (1911–2008)
Richard Feynman (1918–1988)
Julian Schwinger (1918–1994)
Feza Gürsey (1921–1992)
Chen Ning Yang (1922– )
Freeman Dyson (1923–2020 )
Gunnar Källén (1926–1968)
Abdus Salam (1926–1996)
Murray Gell-Mann (1929– )
Riazuddin (1930– )
Roger Penrose (1931– )
George Sudarshan (1931– )
Sheldon Glashow (1932– )
Tom W. B. Kibble (1932– )
Steven Weinberg (1933– )
Gerald Guralnik (1936–)
Sidney Coleman (1937–2007)
C. R. Hagen (1937–)
Ratko Janev (1939– )
Leonard Susskind (1940– )
Michael Berry (1941– )
Bertrand Halperin (1941–)
Stephen Hawking (1942–2018 )
Alexander Polyakov (1945–)
Gerardus 't Hooft (1946– )
Jacob Bekenstein (1947–)
Robert Laughlin (1950–)


Romania: Romania (old spelling: Rumania, Roumania; România, ro.mɨˈni.a) is a country in Eastern and Southeastern Europe. It is north of the Balkan Peninsula, on the Lower Danube River. Western Romania is circled by the Carpathian Mountains. Romania also has a border on the Black Sea. Most of the Danube Delta is found inside Romania. Romania shares borders with Hungary and Serbia to the west, Ukraine to the far northeast, the Republic of Moldova to the near northeast, and Bulgaria to the south.
Romania is a semi-presidential unitary state. It was created when Moldavia and Wallachia joined in 1859. It was given its independence in the Treaty of Berlin of 1878. At the end of World War II, some of its land (close by what is now known as Moldova) was occupied by the USSR. After the Iron Curtain fell in 1989 Romania was liberated from the communist regime. During the 2000s, Romania made changes to the country, such as reform the democratic system, human rights acts, freedom of speech acts, economy and law. That let Romania join the European Union on January 1, 2007.
Romania has the 9th biggest area of land and the 7th biggest population (with 19 million people) of the European Union member states. The capital and biggest city in Romania is Bucharest (București ), with a population of 1.6 million. One of the cities in Transylvania, Sibiu, was named a European Capital of Culture in 2007 and a city in Banat, Timișoara, held the same title in 2023. Romania joined NATO on March 29, 2004.
Origin
The word Romania (Rumania or România) comes from the Romanian word Român, which comes from the Latin word Romanus which means "Roman". English texts still used the word Rumania during World War II. This came from the French word Roumanie.
 History 
See main article History of Romania
Geography
Romania is a part of southeastern Europe. It borders the Black Sea and the Danube River. The Carpathian Mountains lie in the center.
Romania is the biggest country in southeast Europe by population. It has an area of 238391 km2 mi2 0 on. It is the twelfth-largest country in Europe. Most of Romania's border with Serbia and Bulgaria is made by the Danube. The Danube joins the Prut River. The Prut River makes the Moldovan–Romanian border. The Danube then flows into the area of the Black Sea inside Romania. This makes the Danube Delta. The delta is a biosphere reserve and a biodiversity World Heritage Site. Some of the other major rivers in Romania are the Siret, the Olt, and the Mureş. The Siret River runs from the north to the south of Moldavia. The Olt River runs from the Carpathian Mountains to Oltenia. The Mureş runs through Transylvania from the east to the west.
Landscape
The land in Romania is made up of equal parts of mountains, hills, and low-lying areas. The Carpathian Mountains make up a big part of the center of Romania. Fourteen of its mountain ranges are taller than 2000 m ft 0 on on. The tallest mountain in Romania is Moldoveanu Peak, with a peak altitude of 2544 m ft 0 on on.
Rivers
The Danube is the longest river in Romania. Its length inside Romania is about 1000 km mi 0 on. That is almost half of the length of the entire Danube. Almost all of the rivers in Romania are either direct or indirect tributaries of the Danube.
Weather
Romania has a climate that changes between temperate and continental climates. The reason for the climate changes is because Romania is near the coast. Romania has four different seasons. The average temperature during the year is 11 °C °F 1 on in southern Romania and 8 °C °F 1 on in the northern part.
Lots of rain and snow falls on the highest western mountains. Most of this falls as snow. In the southern parts of the country, the amount of rain and snow that falls is around 60 cm in 1 on.
The lowest temperature ever taken in Romania was -38.5 °C °F 1 on, at Braşov in 1944. The highest temperature ever recorded in Romania was 44.5 °C °F 1 on, near Calafat in the 1950s.
Society
These are the development regions of Romania:
 Northeast
 West
 Northwest
 Center
 Southeast
 South
 Bucharest-Ilfov
 Southwest
Language and culture
The official language of Romania is Romanian. The Romanian language is an Eastern Romance language.
Romania has its own culture because of where it is found. It is the point where 3 different areas meet: Central Europe, Eastern Europe, and the Balkans. Romanian culture is a mix of all these areas. The culture of Romania was influenced by the Greeks, Romans, and Slavs. Traditional Romanian cuisine includes mămăligă, a type of Polenta made out of Corn flour, mici, a type of Sausages, Sarmale and Chiftele, a type of meatballs. Popular types of meat in Romania include pork and beef. The most popular alcoholic drink in Romania is Țuică. Romania is a orthodox christian state, and borrows western holidays like Christmas and Easter, while having its own non-working holidays, like Great Union Day, celebrating Romania's union with Transylvania. Ie is a Romanian traditional costume, worm during Great Union Day and Little Union Day (holiday celebrating Wallachia's union with Moldavia). 
Religion
Romania is a secular state. This means Romania has no national religion. The biggest religious group in Romania is the Romanian Orthodox Church. It is an autocephalous church inside of the Eastern Orthodox communion. In 2002, this religion made up 86.7% of the population. Other religions in Romania include Roman Catholicism (4.7%), Protestantism (3.7%), Pentecostalism (1.5%), Islam (1%) and the Romanian Greek-Catholicism (0.9%).
Cities
Bucharest is the capital of Romania. It also is the biggest city in Romania, with a population of over 2 millions peoples.
There are 5 other cities in Romania that have a population of more than 300,000 people. These are Iaşi, Cluj-Napoca, Timişoara, Constanţa, and Craiova. Romania also has 5 cities that have more than 200,000 people living in them: Galaţi, Braşov, Ploieşti, Brăila, and Oradea but in [[Brașov Sacele is Lața Adrian stollen all monney 300 milions dolars for coruptions in USA , with Lața Viorel was Primary in this town ,în 2005 .this monney was from investitions for Sacele Brașov.prison 50 years for Familly gipsy Lața Viorel .]]
Thirteen other cities in Romania have a population of more than 100,000 people.
Arts
Romania was home to a mixture of great artists. Early pioneers of Romanian enlightenment include Dimitrie Cantemir, Ion Budai Deleanu and Dinicu Golescu. Romanian writers Mihai Eminescu, Ion Creangă, Ion Luca Caragiale and Ioan Slavici are hailed as "The great classics" of Romanian literature. 20th century writers that rose to prominence include Mihail Sadoveanu, Lucian Blaga, Mircea Eliade and Tristan Tzara. Nicolae Grigorescu and Theodor Aman are known as founders of modern Romanian art, while Constantin Brâncuși had international contributions to sculpture. The greatest Romanian composer was George Enescu. Great playwrights in Romania include Eugène Ionesco and Mihail Sebastian. The biggest architectural wonders in Romania include wooden churches, Casa poporului, the Romanian atheneum and the Parliamentary palace. 
Economy
Romania joined the European Union on January 1, 2007. Romania's economy is healthy. Currently, Romania makes around $350 billion in Gross domestic product and a GDP per capita of $16,540.
Long into the 1900s, Romania was still a largely agricultural country. During Communism 1947-1989, the country had planned economy. The transition from planned economy to a market economy after the communist regime led to economic collapse in the 1990s, the reasons was that more money was printed, expensive prices and substantial privatization of the companies, which initially leads to skyrocketing unemployment. The reforms in the 1990s allowed foreign investors for the first time to buy land in Romania. When it was going well for industry in the Latin countries such as France, Italy and Spain, they began to trade with Romania. Foreign companies have expanded in Romania since then, and spurs the market.
Romania has the highest percentage of homeowners in Europe. The fall of communism prompted many Romanians to purchase the flats they lived in cheaply while the country underwent a wave of privatisation and devaluation of the currency.
Education
In Romania school is compulsory for 10 years. Children have the opportunity to be part of a voluntary pre-school for age 3–6 years. After school, students can voluntarily take the entrance exam to high school, which has a range of practical and theoretical lines. There are over 40 higher educational institutions, including five universities and five technical colleges. Tuition is free and is a hot political commitment even at the university. The country's minorities can have instruction in their native language. Since 1989, education has been reformed. But it has been slow and the standard of education varies greatly in different parts of the country, Education has improved the standard of urban compared to rural areas where quality can be very low. Romania participates fully in the EU's education program.
Social welfare
The unemployment rate in Romania is 5% in 2023 and has been low for many years.
Living standards were very low at the end of the Communist era, but the situation improved a little bit during the 1990s. The large privatization resulted in high unemployment and rising prices. In 2010 nearly 10% of the population were in absolute poverty and of these, 90% live in rural areas. The State social insurance system has relatively broad coverage but resources are extremely small.
Reforms have been initiated and in 1999 the health insurance became privatized and paid by the employers and the employees. Several thousand local trade unions were founded after the revolution, which were later combined into federations. These unions and federations have helped organise students, pensioners and the unemployed; because these groups of people all have similar needs, concerns and goals.
By the first quarter of 2011 the average monthly household income is 2,318 Romanian leu (equivalent to approximately £862 USD). Income is 36% higher in the urban area than in the countryside.
The pension system is reformed.
The most worrying thing is the fact that there are more pensioners than the number of working people. because many who dismissed during the privatizations had per-retirement. Romanian Pensioners average pension at the month is at about 190 euros (equivalent to approximately £250-300 USD). The current low average retirement age (55 years for men and 57 years for women) will be gradually increased until 2014, when it gets to 60 years for women and 65 years for men.
Many of the country's Gypsies have no identity cards and are therefore are excluded from the social benefit systems, schools and health care. The State-run health care is free, but the care system is neglected and has deteriorated in recent years due to lack of resources and underpaid staff. In many cases, the patients pay "under the table" to get treatment. There is evidence to suggest that a patient's wealth plays an important role in how they receive medical treatment.
Science and technology
Historically, Romanian researches and inventors have made notable contributions to several fields, such as: aeronautics, medicine, mathematics, computer science/engineering, physics, biophysics, chemistry, biochemistry and biology. In the history of flight, Traian Vuia and Aurel Vlaicu built and flew some of the earliest successful aircraft, while Henri Coandă discovered the Coandă effect of fluidics. Preceding him, Elie Carafoli was a pioneering contributor to the field of aerodynamics in the world.
Victor Babeş discovered more than 50 germs and a cure for a disease named after him, babesiosis; biologist Nicolae Paulescu discovered insulin. Another biologist, Emil Palade, received the Nobel Prize for his contributions to cell biology. George Constantinescu created the theory of sonics, while Lazăr Edeleanu was the first chemist to synthesize amphetamine and also invented the modern method of refining crude oil. Costin Neniţescu found new methods for the synthesis of pirilium salts, of carbenes, tryptamine, serotonin, two new syntheses for the indole nucleus, and a new method of polymerisation of ethylene.
Several mathematicians distinguished themselves as well, among them: Gheorghe Ţiţeica, Spiru Haret, Grigore Moisil, Miron Nicolescu, Nicolae Popescu and Ştefan Odobleja; the latter is also regarded as the ideological father behind cybernetics.
Notable physicists and inventors also include: Horia Hulubei in atomic physics, Șerban Țițeica in theoretical physics, Mihai Gavrilă specialized in quantum theory and discoverer of the atomic dichotomy phenomenon, Alexandru Proca (known for the first meson theory of nuclear forces and Proca's equations of the vectorial mesonic field), Ştefan Procopiu known for the first theory of the magnetic moment of the electron in 1911 (now known as the Bohr-Procopiu magneton), Theodor V. Ionescu, the inventor of a multiple-cavity magnetron (1935), a hydrogen maser in 1947, 3D imaging for cinema/television in 1924 and hot deuterium plasma studies for controlled nuclear fusion, Ionel Solomon known for the nuclear magnetic resonance theory in solids, Solomon equations and photovoltaic devices, Petrache Poenaru, Nicolae Teclu and Victor Toma, with the latter known for the invention and construction of the first Romanian computer, the CIFA-1 in 1955.
The nuclear physics facility of the European Union's proposed Extreme Light Infrastructure (ELI) laser will be built in Romania. Romania currently has 1,400 MW of nuclear power capacity by means of one active nuclear power plant (Cernavodă) with 2 reactors, which constitutes around 18% of the national power generation capacity of the country. This makes Romania the 23rd largest user of nuclear power in the world.
Government
Politics
The Constitution of Romania is found to be based from the Constitution of France's Fifth Republic. It was passed into law on December 8, 1991. after a referendum was held. 73 amendments were added to the constitution in October 2003 to bring the constitution of Romania up to code with the constitution of the European Union.
The legislative branch of the Romanian government is known as the Parliament. It contains two chambers – the Senate, containing 140 members, and the Chamber of Deputies, which has 346 members. The members of both chambers are elected every four years through party-list proportional representation.
The judicial branch of the Romanian government is separate from the other branches. It is made up of a system of courts. The court with the most authority is the High Court of Cassation and Justice, which is the supreme court of Romania. Other courts, including appeal, county, and local courts also make up the judicial branch of the Romanian Government. The way the system of courts works in Romania is modelled off of the French model of law. It is based on civil law.
Divisions
Romania is divided into 41 counties, including the municipality of Bucharest, which is also its own county.
Romania is divided further into 319 cities and 2,686 communes. Each of the communes has its own council that is led by a mayor.
 Army 
The Romanian Army is made up of Land, Air, and Naval Forces, which are all led by a Commander-in-chief. The commander-in-chief is given orders by the Ministry of Defense. During war, the President leads the Army. 90,000 people were in the Romanian Army in 2003: 15,000 civilians and 75,000 military people. Of the 75,000 military people in the Romanian Army, 45,800 are in the land forces, 13,250 are in the air forces, 6,800 are in the naval forces, and 8,800 in other areas of the military.


Meitei people in the United Kingdom: Meitei
Meitei people (Mtei ꯃꯩꯇꯩ ꯃꯤꯌꯥꯝ), also referred to as the Manipuris (Mtei ꯃꯅꯤꯄꯨꯔꯤ ꯀꯥꯡꯂꯨꯞ), constitute a small diaspora community in the United Kingdom. Originating from the northeastern Indian state of Manipur and other parts of South Asia, the community is composed of individuals who have migrated for purposes including education, employment, and family reunification. While maintaining aspects of their linguistic and cultural identity, Meitei individuals in the UK participate in various sectors of society and are part of the broader South Asian diaspora in the region.
 Cuisines 
The British Meitei diaspora maintains traditional Meitei cuisine, which includes dishes such as Sareng Thongba, Rou Ataoba Thongba, Ooti, Chagem Pomba, Khamen Kanghau, Thambou Singju, and Bora. These dishes are typically prepared and consumed during Meitei festivals, such as Ningol Chakouba, observed by the diaspora community in Kent.
 Dance and music 
As part of its cultural initiatives aimed at engaging younger members of the British Meitei diaspora, the European Manipuri Association (EMA) organised a performance of Thoibi Jagoi (Mtei ꯊꯣꯏꯕꯤ ꯖꯒꯣꯏ) in traditional Meitei attire. The performance was accompanied by an explanatory segment outlining the symbolic elements and cultural significance of Meitei Jagoi (classical dance).
As part of its continued efforts to foster a sense of community and cultural identity among people of Manipuri origin, the European Manipuri Association (EMA) included a performance of the Meitei-language patriotic song "Ho Ima Poknafam Ima Nang-gumbi Leiroi Ima" (Mtei ꯍꯣ ꯏꯃꯥ ꯄꯣꯛꯅꯐꯝ ꯏꯃꯥ ꯅꯪꯒꯨꯝꯕꯤ ꯂꯩꯔꯣꯏ ꯏꯃꯥ), sung by its members. The performance took place in Worcester, United Kingdom, on 29th May 2013.
Mangka Mayanglambam (Mtei ꯃꯪꯀꯥ ꯃꯌꯥꯡꯂꯝꯕꯝ), a Manipuri folk artiste, performed at the Focus Wales International Music Festival 2022, held in the United Kingdom in May. She presented a selection of Manipuri folk songs, along with a collaborative piece performed with Welsh singer Eadyth Crawford. The performances took place at five concerts in Wrexham, Nottingham, and London from May 5 to 11. The event was part of Ziro FOCUS 2022, a collaboration between FOCUS Wales and the Ziro Festival of Music (India), supported by the British Council and Arts Council of Wales under the Connections through Culture programme.
 Festivals 
Ningol Chakouba (Mtei ꯅꯤꯉꯣꯜ ꯆꯥꯀꯧꯕ), a traditional Meitei festival, was observed by the European Manipuri Association (EMA) on 14th November 2015 in Borstal, Kent, UK, a day later than the traditional celebration in Manipur. The event saw the participation of both new and existing members of the Meitei diaspora from across Europe.
The European Manipuri Association (EMA) organized the Ningol Chakouba festival in Flaunden Village, Hertfordshire, UK, on November 2, 2024. The event was attended by Manipuris from various ethnic backgrounds across Europe.
 Games and sports 
Meitei traditional games Meitei traditional toys
As part of its cultural engagement initiatives targeting younger members, the European Manipuri Association (EMA) organised demonstrations of traditional Meitei sports, including Thouri-Chingnabi (Mtei ꯊꯧꯔꯤ ꯆꯤꯡꯅꯕꯤ) and Chaphu-Thugaibi (Mtei ꯆꯐꯨ ꯊꯨꯒꯥꯏꯕꯤ). These activities are regarded as integral components of Meitei cultural and sporting traditions.
On July 24, 2012, the European Manipuri Association (EMA) met all 10 Olympians from the Northeast India in London to extend best wishes ahead of the 2012 Summer Olympics. Out of 10 Olympians, 5 Olympians are from Manipur, namely MC Mary Kom (Boxing), L Bombayla (Archery), Ng Soniya (Weightlifting), Kh Kothajit (Hockey), and L Debendra (Boxing).
 International services 
The European Manipuri Association, United Kingdom, comprising members of the Manipuri diaspora, invested in the "Blooming Manipur" project, inspired by the flourishing of the United Kingdom. With permission from the government of Manipur, the association installed hanging flower pots in the historic Ima Keithel (Mtei ꯏꯃꯥ ꯀꯩꯊꯦꯜ), also known as the Mother's Market, a landmark over 500 years old, located in the heart of Imphal, the capital city of Manipur.
 Military service 
Lieutenant Khwairakpam Robin Singh (Mtei ꯈ꯭ꯋꯥꯏꯔꯥꯛꯄꯝ ꯔꯣꯕꯤꯟ ꯁꯤꯡꯍ), a Manipuri, who was a member of the British Royal Maritime Auxiliary Service (RMAS) Special Forces, was awarded the Conspicuous Gallantry Cross for his actions during a gunfight with Al Qaeda insurgents in Afghanistan in 2011. The award, which is the second-highest military honor, was presented to him on June 19, 2013. He was recognized alongside six other personnel. Additionally, a monetary award of £15,000 was granted in recognition of his bravery.
 Notable people 
 Bishwajit Elangbam (Mtei ꯕꯤꯁ꯭ꯋꯖꯤꯠ ꯑꯦꯂꯥꯡꯕꯝ), a Meitei originated from Manipur, is an Emergency Medicine Consultant and Governance Lead for the Sandwell Emergency Department in Birmingham, UK. He has been appointed as a Visiting Professor at Aston University, UK. He is the first Manipuri Visiting Professor of Emergency Medicine in the UK.
 Rina Nameirakpam Barua (Mtei ꯔꯤꯅꯥ ꯅꯥꯃꯩꯔꯥꯛꯄꯝ ꯕꯔꯨꯋꯥ), a non-resident Manipuri, selected as one of the four finalists for the Asian Women of Achievement Awards in the Businesswoman of the Year - Corporate category. She is an accomplished lawyer and currently holds the position of Vice-President and Legal Head at the UK-based TV channel B4U.
 Associations and organizations 
 The European Manipuri Association (EMA) was founded on 23rd September 2001 in Sheffield, United Kingdom, by a group of volunteers. It works to unite members of the Manipuri diaspora across Europe.


Sunderland: June 2019
Sunderland is in North East England. It was a county borough, and is now part of the City of Sunderland in Tyne and Wear. It sits at the mouth of the River Wear.
Sunderland started as three small villages:
 Monkwearmouth was created in 674 when Saint Benedict Biscop started a monastery. Monkwearmouth is on the north side of the river.
 Bishopwearmouth was founded in 930. It is on the south side of the river.
 Sunderland, at the mouth of the river was a small fishing village. It was given a charter in 1179. The charter gave the people of the small town some rights which people outside the town did not have.
Sunderland grew as a port, mostly selling coal and salt. In the 1300s people began to build ships along the river bank. By 1835, the port of Sunderland was so important that its name was used when the three old villages became a borough. Sunderland became a city in 1992.
A person born in Sunderland is sometimes called a Mackem.
 History 
 Early history 
In 674, Benedict Biscop built the Wearmouth (St. Peter's) monastery. He was given the land by King Ecgfrith of Northumbria. Biscop's monastery was the first monastery built of stone in Northumbria. Biscop brought glass makers from France. This was the start of glass making in Britain.
In 686, the community was taken over by Ceolfrid, and Wearmouth monastery and its other site in Jarrow became very important places of learning in Anglo-Saxon England. The library had about 300 books; all of them were hand written and painted.
The Codex Amiatinus, was written and painted at the monastery and was probably worked on by Bede who was born at Wearmouth in 673.
Bede wrote the Historia ecclesiastica gentis Anglorum (The Ecclesiastical History of the English People) in 731. This is why he is often called The father of English history.
In the late eighth century, the Vikings began to raid the coast, and by the middle of the ninth century, the monastery had been abandoned.
In 930, King Athelstan of England gave the land on the south bank of the river to the Bishop of Durham. This is why the area is still called Bishopwearmouth.
By 1100, the Bishopwearmouth parish included a small fishing village at the mouth of the river (modern day East End) known as 'Soender-land', or Asunder-land which became Sunderland. This settlement was granted a charter in 1179 by Hugh Pudsey, then the Bishop of Durham.
By 1346, ships were being built at Wearmouth. The merchant Thomas Menville started building ships so he could transport the things he wanted to sell.
In 1589, salt making started in Sunderland. Large vats, called ‘’panns’’, of seawater were put on coal fires. When the water boiled, the salt was left behind. This is known as salt panning. Today, the road leading to where the pans were is still called Pann's Bank. It is on the river bank near the city centre. As more coal was needed to heat the salt pans, coal mining started in the area. Only poor quality coal was used in salt panning; the best coal was sold and shipped out of the town. This is why the port began to grow. This put Sunderland in competition for the first time with its coal-trading neighbour Newcastle.
 17th and 18th centuries 
Before the English Civil War in 1642, King Charles I said Newcastle could be the only town in the east of England which could send coal by ship. This had a big impact on Sunderland, which was selling more and more coal. This created resentment towards Newcastle and towards the idea of having a king. When the civil war began, the mainly Protestant Sunderland sided with Parliament against the mostly Catholic Newcastle. This was good for Sunderland's business, because Parliament blockaded (blocked) the Tyne. This stopped the Newcastle coal trade and allowed the Sunderland coal trade to grow. When an army from Scotland came to fight the King, its base was set up in Sunderland.
The River Wear was not very deep, so the coal had to be loaded onto big boats called keels and taken downriver to the coal ships which were called colliers.
In 1719, Sunderland and Bishopwearmouth were too big for the only parish church, which was in Bishopwearmouth. A new parish of Sunderland was created and Holy Trinity, Sunderland parish church was built. The three original settlements of Wearmouth (Bishopwearmouth, Monkwearmouth and Sunderland) had started to join up. This was because of the success of the port of Sunderland as well as the salt panning and the shipbuilding along the banks of the Wear. Around this time, Sunderland was also known as 'Sunderland-near-the-Sea'.
 19th century 
 Cholera 
Local government was divided between the three churches (Holy Trinity, Sunderland, St. Michael's, Bishopwearmouth, and St. Peter's Church, Monkwearmouth). When cholera broke out in 1831, the "select vestrymen", as the church councillors were called, did not know what to do about the epidemic. Many were frightened to say that a disease has started because it might stop their businesses from making money. They printed notices which said there was no disease in the town, and saying that the doctors who said that there was disease did not know what they were talking about.
Sunderland was a big trading port at the time. It was the first British town to be affected by 'Indian cholera' epidemic. The first victim, William Sproat, died on 23 October 1831. Sunderland was put under quarantine, so that people could not leave the town. The port was blockaded, so that ships could not spread the disease to other ports. But in December of that year, cholera was in Gateshead and it spread across the country, killing about 32,000 people.
Jack Crawford was one of the first to die in the epidemic. There are two statues honouring Jack, one in Mowbray Park near the Civic Centre, and the other next to Holy Trinity Church.
Sunderland got its first Member of Parliament after the Reform Act of 1832, and the Borough of Sunderland was created in 1836, although impatient citizens elected Andrew White to be Mayor in December 1835.
Robert Rawlinson was sent to Sunderland in February 1850 by the General Board of Health. His report showed the problems because there was no sewage system or drains.
 Bridges 
The river at Sunderland is in a narrow valley, and the town grew up on plateaus high above the river. This meant it never had the problem of allowing people to cross the river without stopping high masted vessels. Rowland Burdon MP pushed for the Wearmouth Bridge, which was built in 1796. It was the second iron bridge ever built. Only the famous Iron Bridge itself is older, but Wearmouth bridge was over twice as long and only three-quarters the weight of the Iron Bridge. Wearmouth Bridge was the biggest single span bridge in the world. Farther up the river, another bridge, the Queen Alexandra Bridge, was built in 1910, linking the areas of Pallion and Southwick. It was designed for trains to run across, too, but the railway section was never completed.
 Victoria Hall Disaster 
The Victoria Hall was a large concert hall on Toward Road facing Mowbray Park. On 16 June 1883, 183 children died. During a variety show, children rushed down the stairs for treats. At the bottom of the staircase, the door only opened inward and was bolted so that only one child at a time could get through. The children pushed down the stairs to the door. Those at the front were trapped, and were crushed by the weight of the crowd behind them.
The Victoria Hall disaster is still the worst of its kind in Britain. A memorial statue, which is a crying mother holding a dead child, is now back in Mowbray Park with a protective canopy. The newspaper reports of the tragedy were so shocking that an inquiry was set up. This committee said that public buildings should have outward opening emergency exits. This led to the invention of 'push bar' emergency doors. This law still remains in full force to this day. The Victoria Hall was used until 1941 when it was destroyed by a German bomb.
 20th century to present 
As the traditional industries have declined, electronics, chemicals, and paper making have replaced them. Some of these new industries, are in Washington, which has more space to allow purpose built factories. The Nissan car plant and the nearby North East Aircraft Museum are on the site of the old Sunderland Airport.
Since 1990, industries along the banks of the Wear have changed a lot. Housing, shopping parks and business centres have been built where the shipbuilding yards were. The National Glass Centre is also there, next to the University of Sunderland’s new "St Peter’s Campus". On the south side of the river, the old Vaux Brewery site has been cleared so that new houses, shops and offices can be built close to the city centre.
Sunderland was the one of the most heavily bombed areas in England during World War II. As a result, much of the town centre was rebuilt in a boring concrete style. But some fine old buildings remain. These include Holy Trinity, built in 1719 for an independent Sunderland, St. Michaels's Church, built as Bishopwearmouth Parish Church and now known as Sunderland Minster and St. Peter's Church, Monkwearmouth, part of which dates from 674 AD, and was the original monastery.
St. Andrew's Roker, so-called "Cathedral of the Arts and Crafts Movement", contains work by William Morris, Ernest Gimson and Eric Gill.
 Civic history 
Sunderland was made a municipal borough of County Durham in 1835. Under the Local Government Act 1888, it was given further status as a county borough with independence from county council control. In 1974, under the Local Government Act 1972, the county borough was abolished and its area combined with that of other districts to form the Metropolitan Borough of Sunderland in Tyne and Wear. See City of Sunderland.
 Motto 
Sunderland has the motto of Nil Desperandum Auspice Deo. This means Never Despair, Trust In God
 Geography 
Much of the city is on a low range of hills running parallel to the coast. On average, it is around 80 metres above sea level. Sunderland is divided by the River Wear which passes through the middle of the city in a deep valley, part of which is known as the Hylton gorge. The only two road bridges connecting the north and south halves of the City are the Queen Alexandra Bridge at Pallion and the Wearmouth Bridge just to the north of the City centre. A third bridge carries the A19 trunk road over the Wear to the West of the City.
Most of the suburbs of Sunderland are west of the city centre with 70% of its population living on the south side of the river and 30% on the north side. The city extends to the seafront at Hendon and Ryhope (on the south) and Seaburn (on the north).
The area is part of the Anglican Diocese of Durham. It has been in the Roman Catholic Diocese of Hexham and Newcastle since the Catholic bishops returned in 1850.
 Alphabetical street naming of suburbs 
Some Sunderland suburbs have most streets beginning with the same letter:
 A: Farringdon
 B: Town End Farm
 C: Hylton Castle
 D: Seaburn (some parts)
 E: Carley Hill
 F: Ford Estate
 G: Grindon
 H: Hylton Lane
 K: Downhill
 M: Moorside
 P: Pennywell and Plains Farm
 R: Red House
 S: Springwell
 T: Thorney Close
 W: Witherwack
 Climate 
Sunderland has cool winters and warm summers. Being on the coast, Sunderland is a little warmer in the winter than the national average, but a little cooler in summer. Average rainfall is below the UK national average due to an east coast location.
As with most UK east-coast towns, Sunderland sometimes gets sea fog known locally as Fret. This is most common in the summer months (April - September). These frets can be very dense, are often very localised, and can appear and disappear in a matter of minutes.
 Demographics 
Sunderland is the largest city, by population and area, between Leeds and Edinburgh.
The City of Sunderland is the 22nd largest borough in England and the largest in the North East. However, as well as including the Sunderland it also includes a number of surrounding towns and villages, such as Washington, Houghton-le-Spring and Hetton-le-Hole.
 Ethnicity 
98.1% of the population are white, with 1% Asian and 0.4% mixed-race.
In 2001, the most ethnically mixed ward of the city was the (now abolished) Thornholme area - just to the south of the city centre Thornholme included the suburbs of Ashbrooke and Eden Vale. Here, 89.4% are white, 7.8% are Asian and 1.3% are mixed-race.
The least ethnically diverse wards are in the north of the city. The area of Castletown is made up of 99.3% white, 0.4% Asian and 0.2% mixed-race.
 Religion 
According to census statistics, 81.5% of Sunderland residents class themselves as Christian, 9.6% have no religion, 0.7% are Muslim and 7.6% did not wish to give their religion.
Only 114 people of Jewish faith live in Sunderland. There was no Jewish community before 1750, but then a number of Jewish businessmen from across the UK and Europe settled in Sunderland. A Rabbi from Holland was working in the city in 1790. The Jewish community has been shrinking since the mid 20th century. Many Sunderland Jews left for bigger Jewish communities in Britain or to Israel. The Jewish primary school, the Menorah School, closed in July 1983. The synagogue on Ryhope Road (opened in 1928) closed at the end of March 2006.
 Culture and attractions 
 Literature and art 
Lewis Carroll often visited to the area. He wrote most of "Jabberwocky" at Whitburn as well as "The Walrus and the Carpenter". Some parts of the area are believed to be the inspiration for his Alice in Wonderland stories, such as Hylton Castle and Backhouse Park. There is a statue to Carroll in Whitburn library. Lewis Carroll was also a visitor to the Rectory of Holy Trinity Church, Southwick, beforeSouthwick became a part of Sunderland. Carroll's connection with Sunderland, and the area's history, is documented in Bryan Talbot's 2007 graphic novel Alice in Sunderland.
More recently, Sunderland-born Terry Deary, writer of the series of Horrible Histories books, has become famous, and many others such as thriller writer Sheila Quigley, are following his lead.
The Manchester painter, L S Lowry, was another frequent visitor, staying in the Seaburn Hotel in Sunderland. Many of his paintings of seascapes and shipbuilding are based on Wearside scenes.
The Northern Gallery for Contemporary Art on Fawcett Street and Sunderland Museum and Winter Gardens have exhibitions and installations from new and established artists alike. Sunderland Museum has a big collection of LS Lowry. The National Glass Centre on Liberty Way also exhibits a number of glass sculptures.
 Music 
Sunderland has produced a number of musicians that have gone on to reach international fame, most notably Dave Stewart of the Eurythmics. Kenickie, which featured Lauren Laverne on vocals, also achieved a top ten album and wide critical acclaim in the mid-to-late-1990s.
In recent years, the underground music scene and the Sunderland Music Project have helped the likes of The Futureheads and Field Music gain national recognition. In 2004, music magazine NME put Sunderland came 8th in a list of the "coolest" music places in the UK.
Other famous Mackem musicians include punk rockers The Toy Dolls, who broke the top five of the charts with "Nellie the Elephant" in December 1984; the lead singer of dance outfit Olive, Ruth Ann Boyle, who now works with Enigma; A Tribe of Toffs made number 21 with their cult hit "John Kettley is a weatherman" in December 1988; Alex Kapranos of the band Franz Ferdinand also grew up in Sunderland and South Shields.
On the 7 and 8 May 2005, Sunderland hosted the BBC Radio 1 Big Weekend concert - the UK's largest free music festival. The event was held at Herrington Country Park, in the shadow of Penshaw Monument and was attended by 30,000 visitors.
Sunderland does not have a big music venue such as the MetroRadio Arena or the Carling Academy in Newcastle. The Empire Theatre sometimes plays host to music acts, and has attracted Deacon Blue and Journey South to the city in recent years. McFly played there in April 2007. In the past it has also welcomed major bands such as The Beatles and The Kinks.
Independent, a city centre nightclub/music venue, satisfies underground music lovers, having previously played host to Keane, Franz Ferdinand, Kasabian, Kaiser Chiefs, Maxïmo Park and Snow Patrol when they were largely unknown. More recently, Doves and Tim Burgess have performed DJ sets on club nights, and in summer 2007 the club hosted gigs from established bands such as The Zutons and The Maccabees. The Manor Quay, the students' union on the campus of the University of Sunderland has also hosted the Arctic Monkeys, Maxïmo Park, 911, the Levellers and Girls Aloud in the past three years.
Clint Boon sometimes deejays in indie venue Ku Club, and the Bluetones did a set there in 2006.
"CoSMOS", the City of Sunderland Millennium Orchestral Society’’ was set up in 2000 to mark the millennium.
 Theatre 
The Sunderland Empire Theatre, opened in 1907, is the largest theatre in the North East. It reopened in December 2004, following a big redevelopment, making the stage bigger. Now it can stage West End shows such as Miss Saigon, Starlight Express and My Fair Lady. The Empire is the only theatre between Leeds and Glasgow big enough to put on such shows.
The Birmingham Royal Ballet have a season at the Sunderland Empire every year, and it is thought of as the company's north-east home.
The Royalty Theatre is the home to the (amateur) Royalty Theatre group who also put on a number of low-budget productions throughout the year. Well-known movie producer David Parfitt belonged to this company before achieving worldwide fame.
 Events 
Each year on the last weekend in July, the city hosts the Sunderland International Airshow. It takes place along the sea front at Roker and Seaburn, and is attended by over 1.2 million people annually. It is the largest free airshow in Europe.
Sunderland also hosts the free International Festival of Kites, Music and Dance, which attracts kite-makers from around the world to Northumbria Playing Fields, Washington.
Every year, the city hosts a large Remembrance Day memorial, believed to be the largest in the UK outside of London.
HMS Ocean, a Helicopter Landing Ship is Sunderland's adopted Royal Navy ship. The crew of HMS Ocean regularly visit the city.
At Christmas, Sunderland has a German market in the city centre selling German-made wooden goods, and German food. It also hosts a large ice rink in Mowbray Park, which is part of the wider, regional North East Winter Festival.
 Attractions 
Traditional attractions for visitors to Sunderland include Penshaw Monument, the Souter Lighthouse (the first electrically powered lighthouse in the world), the 15th century Hylton Castle, the Wildfowl park in Washington, and the beaches of Roker and Seaburn.
The National Glass Centre opened in 1998, reflecting Sunderland's distinguished history of glass-making. The centre has never been as successful as hoped.
Sunderland Museum and Winter Gardens, on Borough Road, was the first publicly funded museum in the country outside London. It was opened by Ulysses S. Grant shortly after he stopped being US President. The museum has a big collection of the locally produced Sunderland Lustreware pottery. The new City Library Arts Centre, on Fawcett Street, also houses the Northern Gallery for Contemporary Art.
The City of Sunderland has been commended several times on its commitment to preserving its natural environment. Sunderland has won awards from the Britain in Bloom group in 1993, 1997 and 2000.
 Economy and industry 
 See: List of companies in Sunderland
Sunderland is one of the most deprived cities in the North of England. 11 of the 25 wards featuring in the list of the 2000 most deprived wards in England. The most deprived areas are Southwick to the north of the river and Thorney Close to the south - both with chronic levels of unemployment, although the city is performing better than the North East as a whole.
 Traditional industry 
Once called the "Greatest Shipbuilding Town in the World", ships were built on the Wear from at least 1346 onwards. The Port of Sunderland was expanded in the 1850s when the Hudsons Dock were built for the River Wear Commissioners. Robert Stephenson helped the engineers.
Competition from overseas caused a downturn in demand for Sunderland built ships toward the end of the twentieth century. The last shipyard in Sunderland closed in 1988.
Sunderland, part of the Durham coalfield, has a coal-mining heritage that dates back centuries. At the peak in 1923, 170,000 miners were employed in County Durham alone, as labourers from all over Britain, including many from Scotland and Ireland, entered the region. As demand for coal fell after World War II, mines began to close across the region, causing mass unemployment. The last coal mine closed in 1994. The site of the last coal mine, Wearmouth Colliery, is now the Stadium of Light, and a miner's Stephenson lamp monument stands outside of the ground to honour the heritage of the site.
Glass has been made in Sunderland for around 1,500 years. But overseas competition has forced the closure of all of Sunderland's glass-making factories. Corning Glass Works was one of the last. It was in Sunderland for 120 years, until 31 March 2007
Vaux Breweries was established in the town centre in the 1880s and for 110 years was a major employer. The brewery was finally closed in July 1999. Vaux in Sunderland and Wards Brewing Company in Sheffield had been part of the Vaux Group, when both breweries closed the group started to concentrate on its hotels which were in The Swallow Group. In the autumn of 2000 even this was taken over by Whitbread PLC.
 Rejuvenation 
Sunderland's economy began to get better after the 1980s.
The giant Nissan factory moved in, and new service industries arrived. Doxford International Business Park, in the south west of the city, has attracted a host of national and international companies.
The former shipyard areas along the River Wear have also been transformed. Instead of the old industry new developments have been built, including:
 St. Peter's Campus of the University of Sunderland;
 North Haven, executive housing and marina at the old North Dock at Roker;
 the National Glass Centre, by St. Peter's Church;
 the Stadium of Light the 49,000-capacity home of Sunderland A.F.C.;
 Hylton Riverside Retail Park, a large shopping outlet centre at Castletown.
 Echo 24 luxury apartments near the city centre.
Sunderland Corporation's massive post-war housing estate developments, such as Farringdon, Pennywell, Grindon, Hylton Red House, Hylton Castle, Thorney Close and Town End Farm, together with earlier developments, have all passed into the ownership of Gentoo (once called Sunderland Housing Group), a private company and a "Registered Social Landlord". Since the transfer in 2000 there have been a lot of improvements to the quality of social housing in the city.
The central business district of Sunderland has also been redeveloped and improved. In 2000, The Bridges shopping centre was extended to attract national chain stores. In November 2004, after several years with no cinema, a Cineworld multiplex opened in the new River Quarter, an entertainment complex towards the east of the City Centre. The Cinema was taken over by the Empire Multiplex Cinema Company in mid 2006. The previous ABC Cinema, situated on the corner of Park Lane and Holmeside, had been derelict for a number of years until it reopened late in 2005 as The Point, with three bars and the Union nightclub.
The arrival of Roy Keane as Sunderland AFC's new manager in August 2006 has had a massive impact in Sunderland's once limited tourism industry. Keane has proved a big pull for the city in terms of attracting tourists to Sunderland, with the Tourism Office reporting a dramatic rise in the number of football fans coming to the city "mentioning his name" as early as October 2006, just six weeks after Keane's appointment as manager. Airline Ryanair, moreover, recorded a 10% increase in passenger numbers travelling to Newcastle Airport on Fridays before a Sunderland home game, some 600 more than on other Fridays. The Tourism Office believes Keane's attachment to the city is causing a knock-on effect on local restaurants, bars and attractions in that more tourists are "making a weekend of it" after watching the football.
Sunderland panoramic riverside.jpg 900px Sunderland riverside at sunset
 Transport 
 Rail 
Sunderland station was rebuilt in November 1965 for football teams and officials from countries who were playing at Roker Park when England hosted the 1966 World Cup. It is served by Northern Rail services between Newcastle and Middlesbrough, and Grand Central services to York and London
 Metro 
In 2002, the Tyne and Wear Metro system was extended to Sunderland. The local Metro ends at South Hylton after calling at Sunderland Rail Station and Park Lane Bus Station. Metro trains are quite frequent and travel between Newcastle International Airport and Newcastle upon Tyne in the north and South Hylton at the southern end of the line. However, the Metro extension has not been viewed as a huge success with frequency of services cut due to a lack of demand.
 Bus 
A multimillion-pound transport interchange at Park Lane was opened on 2 May 1999 by the then Brookside actor Michael Starke. With 750,000 passengers per year it is the busiest bus and coach station in Britain after Victoria Station in Central London, and has won several design awards. A new Metro station was built underneath the bus concourse to provide a direct interchange as part of the extension to South Hylton in 2002.
 Cycle 
There are a number of cycle routes that run through and around Sunderland. The National Cycle Network National Route 1 runs from Ryhope in the south, through the centre of the city, and then along the coast towards South Shields. Britain's most popular long distance cycle route - The 'C2C' Sea to Sea Cycle Route - traditionally starts (or ends) when the cyclist dips their wheel in the sea on Roker beach. The 'W2W' 'Wear-to-Walney' route, and the 'Two-Rivers' (Tyne and Wear) route also end in Sunderland.
 Famous residents 
Developer of the electric lightbulb Joseph Swan, agony aunt Denise Robertson, rockers 'The Futureheads' and Alex Kapranos of 'Franz Ferdinand', Civil liberty campaigner Chris Mullin MP, radio DJ and singer Lauren Laverne, football manager Bob Paisley, actor James Bolam, movie producer David Parfitt, lead singer of 'Olive' Ruth-Ann Boyle, author Lewis Carroll, artist LS Lowry, journalist Kate Adie, and the Venerable Bede are a few of the many famous people born in or associated with Sunderland.


Isa: Isa or ISA may refer to:
Places
 Isa, Amur Oblast, Russia
 Isa, Kagoshima, Japan
 Isa, Nigeria
 Isa District, Kagoshima, former district in Japan
 Isa Town, middle class town located in Bahrain
 Mount Isa, Queensland, Australia
 Isa (river), a river in Belarus
People
 Isa (name), an Arabic name corresponding to Jesus in English
 Īsā, the name of Jesus in Islam
 Isa Tengblad (born 1998), Swedish singer using the mononym Isa
Isa, real name is Lee Chae-young, singer, member of STAYC
Arts, entertainment, and media
Fictional entities
 ISA (Days of Our Lives), spy agency in TV series
 Isa the iguana, in TV series Dora the Explorer
Interplanetary Strategic Alliance (ISA), military alliance in videogame saga Killzone
Other uses in arts, entertainment, and media
 Isa (album), a 2004 album by Enslaved
 Isa (comics), of graphic novel series Les Passagers du vent
 Isa (movie), a 2014 television movie
 Isa, a dance in music of the Canary Islands
Computing
 Industry Standard Architecture, a PC computer bus standard
 Instruction set architecture, the specification for data types, registers, instructions, etc. for a given computer hardware architecture
 Is-a, a relationship between abstractions in programming
 Internet Security and Acceleration, a network router, firewall, antivirus program, VPN server and web cache from Microsoft Corporation
Education
 Indian Squash Academy, Chennai, India
 Independent Schools Association (Australia), mainly for sports
 Independent Schools Association (UK)
 Iniciativa de Salud de las Americas, Spanish name for Health Initiative of the Americas
 Institute for the Study of the Americas, University of London, England
 Instituto Superior de Agronomia, an agronomy faculty in Lisbon, Portugal
 Instituto Superior de Arte, an art school in Havana, Cuba
 International School Amsterdam, the Netherlands
 International School Augsburg
 International School of Aleppo, Syria
 International School of Athens, Greece
 International School of the Americas, San Antonio, Texas
 International Studies Association
 Islamic Saudi Academy
Finance
 Income share agreement, US, a borrowing agreement sometimes used for tuition loans
 Individual savings account, UK
 International Standards on Auditing
 Israel Securities Authority
Government
 Independent Safeguarding Authority, former UK child protection agency
 Intelligence Services Act 1994, UK
 Intelligence Support Activity, of the US Army
 Internal Security Agency, secret service and counter-espionage agency in Poland
 International Seabed Authority, for mineral-related activities
 International Searching Authority, for patents
 International Solar Alliance
 Interoperability Solutions for European Public Administrations, EU
 Invention Secrecy Act
 Iranian Space Agency
 Israel Security Agency or Shin Bet, Israel
 Israel Space Agency
 Israel State Archives, the national archive of Israel
 Italian Space Agency
Organizations and brands
 Industry Super Australia, the peak body for Industry superannuation funds in Australia
 Information Systems Associates FZE, an aviation software house
 Innovative Software Applications, a company taken over by Sorcim in 1982
 International Seabed Authority
 International Socialist Alternative, an international association of Trotskyist political parties.
 International Society of Arboriculture, a non-profit botanical organization
 International Society of Automation, a non-profit professional organization for engineers, technicians, and students
 International Sociological Association
 International Soling Association
 International Surfing Association, the world governing authority for the sport of surfing
 Irish Sailing Association, the governing body for sailing in Ireland
 International Slackline Association
Science
 Isosaccharinic acid, a six-carbon sugar acid
 Intrinsic sympatheticomimetic activity, a term used with beta blockers that are partial agonists
 Infectious salmon anemia, a viral disease of salmon
 International Standard Atmosphere, an atmospheric model of the Earth
Other uses
 Intelligent speed adaptation, systems to automatically enforce vehicle speed limits
 International Symbol of Access, blue and white wheelchair symbol
 ISA Brown, type of chicken
 Ideological state apparatus, a theory by Louis Althusser
geo


Human: Human
  Akha cropped hires.JPG 
  An adult human male (left) and female (right) from the Akha tribe in Northern Thailand
  0.35 mya to present Middle Pleistocene – Recent
  Homo sapiens
  sapiens
  Linnaeus, 1758
  Subspecies
  World human population density map.png
  Homo sapiens population density
  LC
  IUCN3.1
A human is a member of the species Homo sapiens, which means 'wise man' in Latin. Carolus Linnaeus put humans in the mammalian order of primates. Humans are a species of hominid, and chimpanzees, bonobos, gorillas and orangutans are their closest living relatives.
Humans are mammals. They are also social animals. They usually live in groups. They help and protect each other. They care for their children. Humans are bipedal, which means they walk on two legs.
Humans have a complex brain, which is much larger than that of the other living apes. They use language, make ideas, and feel emotions. This brain, and the fact that arms are not needed for walking, lets humans use tools. Humans use tools far more than any other species. Their tools are very advanced.
Humans first came from Africa. There are humans living on every continent. As of 2023, there were over 8.1 billion living on Earth. Overpopulation is a problem.
 Important features 
Humans have a long period of development after birth. Their life depends less on instinct than other animals and more on learning. Humans are also born with their brains not so well developed as those of other mammals. This makes for an unusually long childhood, so family life is important. If their brains were better developed at birth, their head would be larger, and this would make birth more difficult. In birth, the baby's head has to get through the 'birth canal', the passageway through the mother's pelvis.
Many animals use signs and sounds to communicate with each other. But humans have language. It lets them express ideas by using words. Humans are capable of abstract ideas and can communicate them to others. Human language can express things which are not present or talk about events that are not happening at that time. The things might be elsewhere, and the events may also have occurred at another place or time.
No known animals have a system of communication that is as elaborate as human language. By using words to communicate with each other, humans make complex communities with laws, traditions and customs. Humans like to understand the world around them. They try to explain things through myth, science and philosophy. Wanting to understand things has helped humans make important discoveries.
Humans are the only species living today known to build fires, to cook their food and wear clothes. Humans use more technology than any other animal on Earth ever has. Humans like things that are beautiful and like to make art, literature and music. Humans use education and teaching to pass on skills, ideas and customs to the next generations.
Origins
Humans are part of the animal kingdom. They are mammals, which means that they give birth to their young, and females feed their babies with breast milk. Humans belong to the order of primates. Apes like gorillas, orangutans, chimps, and gibbons are also primates. 
The closest living relatives of humans are the two chimpanzee species: the common chimpanzee and the bonobo. Scientists have examined the genes of humans and chimpanzees and compared their DNA. The studies showed that 95% to 99% of the DNA of humans and chimpanzees is the same.
Biologists explain the similarity between humans and other hominoids by their descent from a common ancestor. In 2001, a hominid skull was discovered in Chad. The skull is about 7 million years old and has been classified as Sahelanthropus tchadensis. This skull may show that the date at which humans started to evolve (develop differently) from other primates is 2 million years earlier than scientists had previously thought.
Humans are part of a subfamily called the Homininae (or hominins), inside the hominids or great apes.
There used to be other types of hominins on Earth. They were similar to but not the same as modern humans. Homo sapiens are the only type of hominins who are alive today. The earliest known fossils of genus Homo have been called Homo habilis (handy man). The first fossils of Homo habilis were found in Tanzania. Homo hablilis is thought to have lived about 2.2 to 1.7 million years ago. Another human species thought to be an ancestor of the modern human is Homo erectus. There are other extinct species of Homo known today. Many of them were likely our 'cousins', as they developed differently to our ancestors. Different species of plants and animals moved from Africa to the Middle East, and then elsewhere. Early humans may have moved from Africa to other parts of the world in the same way.
 Out of Africa 
The first truly modern humans seem to have appeared between 300,000 and 200,000 years ago in East Africa. In paleontology, 200,000 years is a "short" time. So, scientists speak of a "recent single origin" of humans. Some of these early humans later moved out from Africa. By about 90,000 years ago, they had moved into Eurasia. This was the area where Neanderthals, Homo neanderthalensis, had been living for a long time (at least 350,000 years).
By about 42,000 to 44,000 years ago Homo sapiens had reached western Europe, including Britain. In Europe and western Asia, Homo sapiens replaced the Neanderthals by about 35,000 years ago. The details of this event are not known.
At roughly the same time, Homo sapiens arrived in Australia. Their arrival in the Americas was much later, about 15,000 years ago. All these earlier groups of modern man were hunter-gatherers.
 Civilization 
Early human history is commonly divided into three ages. The time periods are labeled with the material used for tools.
 The Stone Age
 The Bronze Age
 The Iron Age
The "Stone Age" is commonly subdivided into the Paleolithic, Mesolithic, and Neolithic periods.
Up to about 10 thousand years ago, most humans were hunter-gatherers. They did not live in one place. Instead, they moved around as the seasons changed. The start of planting crops for food, called farming, made the Neolithic revolution. Some people chose to live in settlements. This also led to the invention of metal tools and the training of animals. About 6,000 years ago, the first proper civilizations began in places, like Egypt, India, and Syria. The people formed governments and armies for protection. They competed for area to live and resources, and sometimes they fought with each other. About 4,000 years ago, some states took over or conquered other states and made empires. Examples include ancient Greece and the Roman Empire.
Some modern-day religions also began at this time, such as Judaism and Hinduism. From the Middle Ages and beyond, humanity saw an explosion of new technology and inventions. The printing press, the car, the train, and electricity are all examples of this kind of invention. As a result of the developments in technology, modern humans live in a world where everyone is connected, for example by telephone or by internet. People now control and change the environment around them in many different ways.
 Habitats, settlements and population 
In early times, humans usually settled near to water and other natural resources. In modern times, if people need things, they can transport them from somewhere else. Therefore, basing a settlement close to resources is no longer as important as it once was. Since 1800, the number of humans, or population, has increased by six billion. Most humans (61%) live in Asia. The rest live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%).
Most people live in towns and cities. This number is expected to get higher. In 2005, the United Nations said that by the end of that year, over half the world would be living in cities. This is an important change in human settlement patterns: a century earlier in 1900, only 14% of people lived in cities; in 2000, 47% of the world's population lived in cities. In developed countries, like the United States, 80% of the population live in cities.
Humans have a large effect on the world. Humans are at the top of the food chain and are generally not eaten by any animals. Humans have been described as super predators because of this. Because of industry and other reasons, humans are said to be a big cause of global climate change.
 Biology 
 Physical appearance 
Human body measurements differ. The worldwide average height for an adult human male is about 172, and the worldwide average height for adult human females is about 158. The average weight of an adult human is 54 - 64 kg lb on off 0 for females and 70 - 83 kg lb on off 0 for males. Body weight and body type is influenced by genetics and environment. It varies greatly among individuals.
Human hair grows on the underarms, the genitals, legs, arms, and on the top of the head in adults of both genders. Hair will usually grow on the face of most adult males and on the chest and back of many adult males. In human children of both genders, long hair grows only on the top of the head. Although it might look like humans have fewer hairs than most primates, they actually do not. The average human has more hair follicles, where hair grows from than most chimpanzees have. Human hair can be black, brown, red or blond. When humans get older, hair can turn grey or white.
Human skin colors vary greatly. They can be a very pale pink all the way to dark brown. There is a reason why people in tropical areas have dark skins. The dark pigment (melanin) in the skin protects them against ultraviolet rays in sunlight. The damage caused by UV rays can and does cause skin cancer in some people. Therefore, in more sunny areas, natural selection favors darker skin color. Sun tanning has nothing to do with this issue, because it is just a temporary process, which is not inherited. In colder climates, the advantage of light-coloured skin is two-fold. It radiates less heat and absorbs more sunlight. In weaker sunlight, a darker body produces less vitamin D than a lighter body. The selection for lighter skin is driven by these two reasons. Therefore, in less sunny areas,, natural selection favours lighter skin colour.
Humans are not as strong as other primates of the same size. An average female orangutan is at least three times as strong as an average human.
The average human needs 7 to 8 hours sleep a day. People who sleep less than this are generally not as healthy. A child needs even more sleep, 9 to 10 hours on average.
 Life cycle 
The human life cycle is similar in some ways to most other mammals. However, there are some differences. The young grow inside the female mother for nine months. After this time, the baby is pushed out of the woman's vagina, with its brain only half developed. 
Unlike most other mammals, human childbirth is somewhat dangerous. Babies' heads are large, and the mothers pelvis bones are not very wide. Since people walk on two legs, their hips are fairly narrow. This means that birth can be difficult. Rarely, mother or baby may die in childbirth. The number of mothers dying in childbirth is lower in the 21st century. This is because of better medication and treatment. If a difficult birth is foreseen, the foetus can be removed surgically, and incubated (developed, but not in the womb).
In many poor countries, the number of mothers dying is higher. Sometimes it is up to 10 times as many as richer countries.
In the human female, her fertile period in the oestrous cycle is hidden, and mating can take place at any time. That is quite unusual. In mammals generally, the fertile period is very noticeable. Mating only takes place when the female signals her fertility. The human cycle is unusual, and it is thought that there is a reason. Humans band together in tribes which have many people. It helps the tribe if the father of a child is not known for certainty. Men live together and work together in much larger groups than do chimpanzees (our nearest living relatives). They have a collective interest in the tribe. It is thought that the human mating system helps this.
The average human baby weighs 3–4 kg at birth and is 50–60 cm tall. Babies are often smaller in poorer countries and may die early because of this.
Humans have four stages in their lives: childhood, adolescence, adulthood and old age.
Life expectancy is how long you are expected to live. This depends on many things including where you live. The highest life expectancy is for people from Monaco, 89.52 years. The lowest is for people from Chad where life expectancy is only 49.81 years. Human lifespans can be longer than other mammals, even elephants.
 Psychology and neurology 
Psychology is the study of how the human mind works. The human brain is the main controller of what a person does. Everything from moving and breathing to thinking is done by the brain. The human neocortex is huge compared with other mammals. It gives us our thinking ability and the ability to speak and understand language.
Neurology is the study of how the brain works while psychology is the study of how and why people think and feel. Many aspects of life are also influenced by the hormone system, including growth and sexual development. The hormonal system (especially the pituitary gland) is partly controlled by the brain.
Human behaviour is hard to understand, so sometimes, psychologists study animals because they may be simpler and easier to know. Psychology overlaps with many other sciences, including medicine, biology, computer science and linguistics.
 Culture 
Language
Language at its most basic is talking, reading and writing. The study of language is called linguistics. Humans have the most complicated languages on Earth. Although almost all animals communicate, human language is unique. Its use of syntax and its huge learnt vocabulary are its main features. There are over 7,300 languages spoken around the world. The world's most spoken first language is Mandarin Chinese, and the most spoken language is English. This includes speakers of English as a second language.
 Reliability 
This is to explain the difference between features which are long established, and ones which are relatively recent in evolution. The human ability to walk and run upright on two legs is recent. The ability to speak is even more recent. Contrast those two with something ancient, like the way most land vertebrates walk on four legs. 
In every case, the older way is very reliable in its development, and the new tactic is more variable, and involves some learning.
 Art, music, and literature 
Art has existed almost as long as humans. People have been doing some types of art for thousands of years as the picture on the right shows. Art represents how someone feels in the form of a painting, a sculpture or a photograph.
Music has also been around for thousands of years. Music can be made with only your voice, but most of the time, people use instruments. Music can be made using simple instruments only such as simple drums all the way up to electric guitars, keyboards and violins. Music can be loud, fast, quiet, slow or many other different styles. Music represents how the people who are playing the music feel.
Literature is anything made or written using language. This includes books, poetry, legends, myths and fairy tales. Literature is important as without it many of the things we use today, such as Wikipedia, would not exist.
 Race and ethnicity 
Humans often categorize themselves by race or ethnicity. Modern biologists know that human gene sequences are very similar compared to many other animals. This is because of the "recent single origin" of modern humans. That is one reason why there is only one human race.360
Ethnic groups are often linked by linguistic, cultural, ancestral, and national or regional ties. Race and ethnicity can lead to different social treatment called racism.
 Religion and spirituality 
Religion is a belief of faith in a higher being, spirit, or any system of ideas that a group of people believe in. To have faith in a belief is to have the belief without proof that it is true. Faith can bring people together because they all believe in the same thing. Some of the things that religions talk about are what happens after death, why humans exist, how humans came to exist (creation), and what is good to do and not to do (morality). Some people are very religious. Many people believe in one all-powerful god; some people believe in more than one god; some people are atheists who do not believe in a god; and some people are agnostics who are not sure if there is a god.
 Science and technology 
Technology are the things and methods which humans use to make tasks easier. Science is understanding how the universe and the things in it work. Technology used to be quite simple. It was passed on by people telling others until writing was invented. This allowed technology to develop much quicker. Now people understand more and more about the world and the universe. The use of the telescope by Galileo, Einstein's theory of relativity, lasers, and computing are all scientific discoveries. Technology is important to science, to medicine, and to everyday life.
 Warfare 
A war is a lethal fight between large groups of people, usually countries or states. A war involves the use of lethal weapons as both sides try to kill the other. It is estimated that during the 20th century, between 167 and 188 million humans died because of war. The people who fight for a state in wars are called soldiers. The people who fight in wars, but not for a state, are usually called "fighters".
Modern wars are very different from wars a thousand or even a hundred years ago. Modern war involves sabotage, terrorism, propaganda, and guerrilla warfare. In modern-day wars, civilians (people who are not soldiers) are often targets. An example of this is the nuclear bomb dropped on Hiroshima and Nagasaki at the end of World War II. The bombs killed as many as 140,000 people in Hiroshima and 80,000 in Nagasaki by the end of 1945, about half on the days of the bombings. Since then, thousands more have died from wounds or illness because of exposure to radiation released by the bombs. In both cities, the overwhelming majority of the dead were civilians. In Germany, Austria, and Great Britain, conventional bombs were used. About 60,595 British and 550,000 German civilians were killed by planes bombing cities.


Science: Science is what we do to find out about the natural world. There are different kinds of science. Natural sciences study nature and the physical world. They include chemistry, biology, geology, astronomy, and physics. Social sciences study people and how societies work. They include, psychology, sociology, and economics. Applied sciences use the things we learn from science to solve problems. They include, engineering and medicine. Science uses mathematics, computer science and logic, which are sometimes called "formal sciences". Science makes observations and experiments. Science produces accurate facts, scientific laws, and theories. 'Science' also refers to the large amount of knowledge that has been found using this process.
Research uses the scientific method. Scientific research uses hypotheses based on ideas or earlier knowledge, which can be categorized through different topics. Then those hypotheses are tested by experiments. People who study and research science and try to find out everything about it are called scientists. Scientists study things by looking at them very carefully, by measuring them, and by doing experiments and tests. Scientists try to explain why things act the way they do, and predict what will happen.
The history of science is thousands of years old. The beginnings of modern science can be found in ancient Egypt and Mesopotamia (around 3000–1200 BCE). They developed early ideas in math, astronomy, and medicine. They influenced the Greeks, who tried to explain what happened in our world using natural causes. Later, during India’s Golden Age, more progress was made. This included the creation of the Hindu–Arabic number system.
After the Western Roman Empire fell during the Early Middle Ages (400–1000 CE), scientific progress in Europe slowed down. But progress started up again during certain periods. In the Islamic world, scholars kept, studied, and made Greek science better during the Islamic Golden Age. Later, when the Byzantine Empire got weaker, its scholars took Greek books to Western Europe, helping start the Renaissance.
From the 10th to 13th centuries, Europe re-learned Greek and Islamic science. This helped cause the scientific revolution in the 16th century. Science began to change a lot. New discoveries removed old ideas. The scientific method became more important. By the 19th century, science became more professional and organized. Instead of calling it “natural philosophy”, it was called “natural science”.
Etymology and Terminology
The history of the word “science” and the terms used in science tell us a lot about how the subject has changed over time and what it means in different cultures and philosophies. The word “science” comes from the Latin word “scientia,” which means “knowledge.” That word came from the verb “scire,” which means “to know.” In ancient Rome, scientia just meant any kind of knowledge you could get through learning or experience. It included many subjects like philosophy, speaking (rhetoric), and math. But back then, it did not mean what we now think of as science. In ancient Greece, a similar idea was called “epistēmē” (ἐπιστήμη). Philosophers like Aristotle and Plato used this word to mean knowledge that could be proven through reason. They saw it as different from “doxa,” which meant opinion, something that might not be true or could change.
The meaning of “science” started to change during the Scientific Revolution in the 1500s and 1600s. During this time, famous thinkers like Galileo Galilei, Johannes Kepler, Francis Bacon, and Isaac Newton began to create a new way of learning about the world. They used observation, experiments, and math to find answers. This method helped form the basis of what we now call modern science. Back then, people did not call it “science”, they called it “natural philosophy”, especially when studying the physical world like motion, planets, or light. The word “scientist” was not even invented until 1834. A man named William Whewell, who studied the history and philosophy of science, came up with it. He suggested “scientist” in a book review to describe someone who studies the natural world in a careful, organized way, just like the word “artist” describes someone who creates art.
Science words (or scientific terms) have changed and grown over time, just like science itself. In the past, many science terms came from Greek and Latin, because those were the main languages used by educated people in Europe for many centuries. For example, the word “biology” comes from the Greek words bios (which means “life”) and logos (which means “study”), so biology means “the study of life.” The word “physics” comes from the Greek word physis, meaning “nature.” “Chemistry” likely comes from the Arabic word al-kīmiyāʾ, which has roots in ancient Egyptian and Greek (Hellenistic) alchemy, a practice that tried to change substances and discover how materials work.
Scientific terms are very important because they help scientists be precise (use exact meanings), communicate clearly, and organize ideas and information. Each area of science has its own set of special words to describe things it studies. For example, in physics, words like “momentum,” “entropy,” and “quantum” have very specific meanings that are different from how they are used in everyday language. In biology, scientists name living things using a system called Linnaean binomial nomenclature. This system gives each organism a Latin name made of two parts: the genus and species. For example, humans are called Homo sapiens. Having standardized scientific words is important for making sure experiments can be repeated correctly (replicability), letting scientists check each other’s work (peer review), and helping scientists from all over the world work together, even if they speak different languages.
Many words used in science today come from the history and culture of the time when they were first used. Some scientific terms actually started out as jokes, creative ideas, or simple descriptions, but they became official because people started using them so much. For example, the term “Big Bang” was first used by astronomer Fred Hoyle in a radio broadcast in 1949. He did not believe in the Big Bang theory and actually used the name to make fun of it. But, the name caught on and is now the main word we use for how the universe began. Another example is the word “quark,” which is used for tiny particles that make up protons and neutrons. Physicist Murray Gell-Mann chose this word from a line in a book called Finnegans Wake by James Joyce. This shows how creativity and language play a role in science.
Scientific words often come from metaphors or comparisons to help people understand complex ideas. For example, the word “cell” in biology was first used by Robert Hooke in 1665. When he looked at cork under a microscope, he saw tiny box-like spaces that reminded him of the small rooms (cells) where monks lived. That is how the name “cell” was born. In computer science, the word “virus” is used to describe a program that can copy itself and infect other programs, just like real viruses do in the human body. Scientists used this name because it helped people understand how these harmful programs behave. These examples show that scientific words often come from real-world ideas, and they help us understand new or difficult concepts by connecting them to things we already know.
The language used in science is always changing to become more fair, clear, and inclusive. In the past, many scientific terms were based on ideas that focused too much on humans, Europe, or one gender. Over time, scientists have worked to replace these words with ones that are more neutral and accurate. For example, in astronomy, the word “planet” was officially redefined in 2006 by the International Astronomical Union (IAU). Because of this change, Pluto was no longer called a full planet, but instead a dwarf planet, which caused a lot of debate. In everyday science language, people now often say “human” instead of “man”, and “humankind” instead of “mankind”. These changes help make science feel more welcoming to everyone, no matter their background or identity.
As science keeps moving forward, new inventions and discoveries also bring new words. For example, scientists discovered CRISPR, a tool that can edit genes. The word CRISPR is an acronym (a short word made from initials) for “Clustered Regularly Interspaced Short Palindromic Repeats.” It shows how scientists create short terms to explain big, complex ideas. New fields like machine learning, artificial intelligence (AI), and quantum computing are also creating new words. These words need to be defined very clearly, so scientists from different areas can understand each other and work together without confusion.
History
Prehistoric science
The period of prehistoric science includes the Palaeolithic, Mesolithic, and Neolithic ages, which lasted from about 2.5 million years ago to around 3000 BCE. Even though these early efforts were not "science" the way we know it today, they showed careful observation, experiments, and the start of organized thinking. One of the first and most important forms of early science was making stone tools. It started with a human ancestor called Homo habilis and continued through different prehistoric cultures like the Acheulean, Mousterian, and Upper Paleolithic. People made tools like hand axes, scrapers, awls (used for poking holes), and spear tips. To do this, they had to understand how stones break, what kinds of rocks work best, and how to hit them with the right amount of force. Archaeologists (scientists who study ancient human history) have found evidence that these early humans learned by trial and error, and they shared their knowledge with others. Over time, they improved their tools to make them stronger and more useful. This kind of hands-on learning and passing down of skills is one of the earliest examples of using science to solve problems, especially in understanding materials and how to use them, what we now call materials science.
Early humans also showed basic knowledge of astronomy, the study of the sky. This can be seen in archaeological discoveries like the Blanchard bone (around 30,000 BCE) and the Lascaux Cave paintings (around 17,000 BCE). These objects and drawings may show that early people were watching the Moon’s phases or recognizing star groups like the Pleiades constellation. One of the earliest sky-watching structures is the Nabta Playa stone circle in southern Egypt, built around 6000 BCE. It is one of the oldest known examples of people using megaliths (large stones) to line up with the summer solstice sunrise, the longest day of the year. It may also have helped track seasonal rains, which were very important for survival in that dry area. These structures show that early people spent years carefully watching the sky, noticing patterns, and trying to predict natural cycles, like when rain or seasons would come. This was an early step toward the science of astronomy.
Another major scientific step happened during the Neolithic Revolution, around 10,000 BCE, when humans started farming. This time period was extremely important because people learned to grow plants and raise animals. They had to understand soil, water, and weather patterns to grow food successfully. Early farmers in places like the Fertile Crescent (in the Middle East), China’s Yellow River valley, and Mesoamerica (Central America) grew crops like wheat, barley, millet, rice, and maize (corn). They watched how these plants grew over many generations and chose the ones with the best traits, like more food, better taste, or the ability to survive without much water. This careful choosing is the beginning of genetics (even though they did not know that word), and their work helped people settle down, build villages, and eventually start civilizations. These farming skills are the beginning of what we now call agricultural science.
Even though prehistoric people did not write things down, they still had surprisingly advanced medical knowledge. One of the most amazing examples is trepanation, a kind of surgery where people removed parts of the skull. Scientists have found skulls from as far back as 7000 BCE in Europe, Africa, and South America that show signs of this surgery, and some of the skulls even show healing, which means people survived the operation. This suggests that early humans had basic knowledge of the body, special tools, and may have used natural medicines, like herbs, to reduce pain or stop infection. Another example is Ötzi the Iceman, a frozen body found in the Alps from around 3300 BCE. His body had tattoos that lined up with places used in acupuncture, a method of healing still used today. He was also carrying a medicinal fungus called Fomitopsis betulina, which may have been used to fight infection.
People in prehistoric times also began using math and measurement. They made tools like tally sticks to help them count. One of the oldest is the Lebombo bone from about 35,000 BCE, and another is the Ishango bone from around 20,000 BCE. These bones have carved marks that might show number patterns, multiples, or even prime numbers. Some scientists think they may also have tracked lunar cycles (the phases of the moon). Later, in places like Mesopotamia and the Indus Valley, early people started using standard measurements. They needed these for storing grain, trading goods, and building things. They created systems to measure volume and weight, which helped them with farming, business, and early forms of engineering.
In prehistoric times, early people showed amazing skills in building large stone structures, which we now call megalithic architecture. One of the oldest examples is Göbekli Tepe, built around 9600 BCE in what is now Turkey. It has huge stone pillars carved with animals, arranged in circles. These stones are very heavy, and moving and placing them would have taken many people working together, using simple tools and their understanding of leverage (how to move heavy things using force and angles). They probably also used basic measuring tools to plan where to put the stones. Other examples, like Stonehenge in England (about 3000 BCE) and the stone lines at Carnac in France, show that people in different places had similar building knowledge. These projects needed not just strength, but also careful planning, measuring, and even watching the sky to line up stones with seasons or sunrise points. This shows early knowledge of engineering and astronomy.
Early humans were also smart about taking care of the environment. They used fire in helpful ways. For example, Australian Aboriginals practiced something called fire-stick farming. They burned certain areas on purpose to help new plants grow, bring animals to the area, and make the land easier to manage. In the Andes Mountains (in South America), ancient farming communities built terraces (step-like farms on hills) and irrigation systems to control water. This helped them farm on steep land and stop soil from washing away. These people understood how to manage natural resources, like water and soil, in ways that are similar to today’s ideas of sustainability (protecting the environment while meeting human needs).
People also started to create ways to record and share information. Early forms of writing included cave art, petroglyphs (pictures carved in rock), and tokens (small clay objects used for counting). In Mesopotamia, around 8000 BCE, people used clay tokens to keep track of food and goods. Over time, this system turned into writing, known as cuneiform. Writing allowed people to store knowledge, like farm records and star charts, and pass it on to future generations. This step, moving from oral traditions (speaking stories and knowledge) to writing things down, helped humans build on knowledge over time. It was the beginning of being able to record science and discoveries so they would not be forgotten.
Ancient science
Ancient science was the early scientific knowledge and inventions created by some of the first civilizations in places like Mesopotamia, Egypt, the Indus Valley, ancient China, and Mesoamerica (Central America). This period lasted from around 3000 BCE to 600 BCE. In Mesopotamia, one of the first places where civilization began, science was used in areas like farming, government, and astronomy. The Sumerians and Babylonians created number systems, including one based on 60 (sexagesimal). This is why we still use 60 minutes in an hour and 360 degrees in a circle today. They were also great at studying the sky. On clay tablets written in cuneiform writing, they recorded things like star charts, calendars, and math problems. Babylonian astronomers carefully watched the Moon and planets, and used math to predict eclipses (when the Moon or Sun is covered) and planet alignments. One of their most important discoveries was the Metonic cycle, which is a 19-year cycle where the Moon’s phases happen on the same days of the calendar again.
Ancient Egyptian science was closely tied to farming, timekeeping, and building large monuments. The Egyptians created a 365-day calendar by watching the star Sirius (which they called Sopdet). Every year, Sirius rose in the sky just before the Nile River flooded. This was a very important event that made the soil good for growing crops. To prepare for this, the Egyptians had to be good at measuring the sky and water levels. They also used science to build huge structures like the pyramids. These amazing buildings needed careful planning, geometry (math involving shapes), and knowledge of materials and surveying (measuring land). Egyptian engineers were skilled at all of these things. A famous document called the Rhind Mathematical Papyrus, written around 1650 BCE, shows that Egyptian students learned math such as fractions, areas, volumes, and ratios. 
The Indus Valley Civilization (around 2600 to 1900 BCE) also had amazing science and technology, even though we still do not fully understand it because their writing system has not been decoded yet. Cities like Mohenjo-Daro and Harappa were built in neat grid patterns, had advanced drainage systems, and used standard sizes for things like weights and bricks. At a site called Lothal, scientists found a dockyard, which shows that people there understood how tides worked and how to build for the sea. The use of uniform bricks and measuring tools also shows they had organized production and possibly government systems to manage it. All of this points to high-level technical knowledge and careful planning.
In ancient China, science grew together with philosophy and government. People studied nature because they wanted to understand it better and use that knowledge to rule wisely. One early book called the I Ching (also called the Book of Changes) was written by at least the late 2nd millennium BCE. It used patterns and binary logic (ideas based on two choices, like yes/no or dark/light) to explain natural cycles and how the universe worked. By the time of the Zhou Dynasty (around 1046–256 BCE), Chinese scientists had invented many useful tools and ideas. They created early earthquake detectors (called seismographs), studied the stars (astronomy), used plants as medicine (herbal medicine), and learned how to work with metals and chemicals (metallurgy). They also made a complex calendar based on both the Moon’s phases and solar seasons. This calendar used a 60-part cycle (called the sexagenary cycle) and showed that they had a very advanced way of measuring time using math. The Chinese were also experts in bronze casting, making tools and objects out of melted metal. They made alloys (mixtures of metals) that had the same recipe every time, using careful control of heat and basic understanding of chemistry.
In Mesoamerica, the Olmec (around 1500–400 BCE) and later the Maya made amazing discoveries in astronomy, math, and building. The Maya used a base-20 number system (instead of base-10 like we use). They invented long count calendars that could track time for thousands of years. They watched the sky carefully and recorded things like the movements of Venus, eclipses, solstices, and planet alignments. Some of this information was written in books called codices, like the Dresden Codex. The Maya used these observations to plan religious festivals, decide when to plant crops, and even schedule political events. They built pyramids and temples that lined up perfectly with events in the sky. They were constantly watching the sky and collecting data, just like modern scientists.
In all of these ancient civilizations, medicine was based on practical experience and observation, even though it was often connected to religion or spiritual beliefs. In Ancient Egypt, a medical text called the Edwin Smith Papyrus (written around 1600 BCE) showed that Egyptian doctors had a logical and scientific approach to treating injuries. It includes detailed instructions for doing surgery and describes how to treat injuries to the head, spine, and arms or legs. It even gave predictions (called prognosis) about how serious the injuries were and what might happen to the patient, depending on where the injury was. In Mesopotamia, doctors used a book called the Diagnostic Handbook by a man named Esagil-kin-apli (around 1069 BCE). This book helped doctors figure out what was wrong with a patient by looking at their symptoms, then choosing treatments. These treatments might include herbal medicine, chants or prayers, and physical treatments like bandages or surgeries. In Ancient China, a book called the Shennong Bencaojing (written in the first millennium BCE) listed hundreds of medicinal herbs and their effects on the body. This book became the base of Traditional Chinese Medicine. It showed how Chinese doctors tested herbs, classified their properties, and wrote down their results, which helped build knowledge over many generations.
These early sciences also depended on good recordkeeping, which allowed people to share and pass on knowledge over time. Each civilization created its own writing system, including cuneiform in Mesopotamia, hieroglyphs in Egypt, oracle bone script in China, and Maya script in Mesoamerica. These writing systems helped people write down important information, like star charts and astronomy, math tables, medical recipes, and instructions for building things Because this knowledge was written down, it could be passed from one generation to the next, even if science back then was usually done by priests, scribes, or royal advisors, not scientists like we think of today.
Classical antiquity
Classical science started in ancient Greece, especially in a city called Miletus. There, early thinkers like Thales (around 624–546 BCE) tried to explain how the world works without using stories about gods or magic. Thales believed that water was the basic substance that everything came from. This idea started a new way of thinking called natural philosophy, which focused on finding natural causes for things we observe in the world. After Thales, other thinkers from Miletus also had big ideas. Anaximander said everything came from something called the apeiron (which means “the boundless” or unlimited). Anaximenes thought air was the most important element.
Another important thinker was Pythagoras (around 570–495 BCE). He believed that numbers and math were the true key to understanding the universe. His school studied geometry, music, and numbers. They discovered that when strings of certain lengths were plucked, they made sounds that matched simple number ratios. This showed a connection between music and math, and supported the idea that the whole universe had a kind of mathematical harmony, a concept called the “music of the spheres.” In medicine, a famous Greek named Hippocrates (around 460–370 BCE) made big changes. He said that illness was not caused by angry gods or magic, but by natural causes like diet, environment, and the balance of fluids in the body. He taught doctors to carefully observe patients, keep records, and study the effects of things like climate and food on health. Hippocrates also created the four-humor theory, which said the body had four fluids: blood, phlegm, black bile, and yellow bile. People believed for many centuries that staying healthy meant keeping these in balance. He also introduced ethical rules for doctors, such as those in the Hippocratic Oath, which is still remembered today. Because of Hippocrates, medicine became more scientific and professional.
Aristotle (384–322 BCE) was one of the most important thinkers in ancient science. He was a student of Plato and later became the teacher of Alexander the Great. Aristotle wrote about many subjects, including biology, physics, astronomy, psychology, and logic. In biology, Aristotle studied sea animals and did some of the first dissections (cutting open bodies to learn how they work). He grouped animals by their physical traits, which helped create early classification systems. In physics and astronomy, he believed the Earth was at the center of the universe (geocentric model), and that everything in the sky moved in perfect circles made of a special substance called aether. He thought the heavens were unchanging, unlike Earth, which was made of earth, water, air, and fire, things that could decay and change. Aristotle also created a famous way of thinking about why things happen, called the four causes. The material cause was what something is made of, the formal cause was the shape or structure of the thing, the efficient cause was what caused it to happen, and the final cause was its purpose or goal.
One of Aristotle’s students, Theophrastus (around 371–287 BCE), took these ideas further, especially in plant science. He wrote books like Enquiry into Plants and On the Causes of Plants, where he tried to classify and describe plants in a clear and organized way. He noticed details like where plants grow, how they reproduce, and how people use them. He divided plants into groups like trees, shrubs, and herbs, and because of his work, he is known as the “father of botany”. His ideas about plants were so good that scientists still read them over a thousand years later. After Alexander the Great died, Greek science continued to grow during the Hellenistic period (323–31 BCE). One of the most famous centers of learning was Alexandria, in Egypt. It had a huge library, scholars from many cultures, and support from powerful leaders. One of the most important scientists there was Euclid (around 300 BCE). He wrote a book called The Elements, which organized everything known about geometry into 13 books. He proved shapes and math rules using logic and step-by-step thinking. This method, called the axiomatic method, became the model for how scientists and mathematicians would work for thousands of years.
Archimedes of Syracuse (about 287–212 BCE) was a brilliant ancient scientist and inventor. He made important discoveries in physics, engineering, and math. One of his most famous ideas is called Archimedes' principle. It says that when you put something in water (or another liquid), the liquid pushes up on it with a force equal to the weight of the liquid the object pushes out of the way. This explains why some things float and others sink. Archimedes also studied levers, pulleys, and other machines, helping to create the basic rules of mechanical engineering. He figured out how to calculate the area and volume of different shapes and came up with a very good estimate for the number pi (π).
Eratosthenes (about 276–194 BCE) was the head librarian at the Library of Alexandria, one of the greatest learning centers of the ancient world. He was good at math, astronomy, and geography, and used these skills to measure the size of the Earth very accurately. He did this by comparing shadows in two cities at the same time during the summer solstice (the longest day of the year). He also invented a system of latitude and longitude to map locations, just like the grid system used in maps today. Eratosthenes tried to create a map of the entire known world. Aristarchus of Samos (about 310–230 BCE) was an early astronomer who had a bold idea: the Sun is at the center of the solar system, not the Earth. This idea is called the heliocentric model. At the time, most people believed the Earth was at the center, so his theory was not accepted, partly because they did not have strong telescopes or enough evidence. Even though his idea was ignored back then, his work later inspired scientists like Copernicus, who helped start the modern understanding of the solar system.
Claudius Ptolemy (about 100–170 CE) lived in Roman Egypt and was a famous ancient astronomer and scientist. He believed that the Earth was at the center of the universe, and he wrote a big book called the Almagest, where he explained this idea using a model called the geocentric model. To explain how the Sun, Moon, and planets move in the sky, he used epicycles, deferents, and equants, complicated ways of showing orbits that looked like circles within circles. Even though this model was wrong (we now know the Sun is at the center), Ptolemy’s system worked well for making predictions and was used for over 1,400 years. Ptolemy did not just study space, he also worked on optics (how light and vision work), maps, and music. He even wrote about astrology.
The Romans were more focused on practical science than on theories. They were great engineers and used science to build things like aqueducts (which carried water), roads, bridges, and concrete buildings. They understood how water flows, how to balance weight, and how to use strong building materials. A Roman engineer named Vitruvius wrote a book called De Architectura in the 1st century BCE, where he talked about architecture, human body proportions, and machines. He combined art and science to show how buildings should look beautiful but also work well. In medicine, a Roman doctor named Galen (around 129–200 CE) became very important. He studied how the body works by examining animals, learning about organs, bones, and how diseases spread. He believed in the four humors (like Hippocrates) and thought that keeping these in balance kept people healthy. Galen’s medical ideas were used in Europe and the Islamic world for many hundreds of years.
Islamic Golden Age
Science during the Islamic Golden Age (from about the 8th to the 14th century CE) was one of the most creative and important times in history. During this period, Muslim scholars made huge advances in astronomy, math, medicine, physics, chemistry, geography, and engineering. This progress happened because of several things which included leaders supported science, especially the Abbasid caliphs who helped fund research and learning. Books from Greece, India, Persia, and China were translated into Arabic, allowing people to learn from many different cultures, and Islamic culture encouraged learning (called ‘ilm in Arabic) and logical thinking. One of the most important places during this time was the House of Wisdom (Bayt al-Hikma) in Baghdad, created by Caliph Harun al-Rashid and expanded by his son Al-Ma'mun. It was a major center where scholars gathered to translate, study, and improve scientific knowledge. They translated famous works from Greek, Persian, and Indian scientists, like Aristotle, Galen, Euclid, and Ptolemy, into Arabic. One key figure was Hunayn ibn Ishaq, who translated over 100 medical books.
In astronomy, Muslim scientists made many improvements to older models from Greece and India. Al-Battani (also known as Albatenius, around 858–929 CE) carefully studied the Sun and calculated the length of the year as 365.2422 days, almost exactly what is known today. Al-Zarqali (also called Arzachel) made the Toledan Tables, which helped European scientists and even influenced Copernicus hundreds of years later. Al-Tusi (1201–1274 CE), working at the Maragheh observatory, invented a math model called the Tusi couple, which helped improve future ideas about how planets move. Muslim astronomers also built observatories (places to study the stars) in cities like Baghdad, Maragheh, Samarkand, and Shiraz. They invented tools like the astrolabe, sextant, and spherical instruments to measure stars and planets very precisely. These tools were used to find the correct times for prayer, determine the direction of Mecca (Qibla), and create Islamic calendars.
In the field of mathematics, Islamic scholars made major breakthroughs, especially in algebra, arithmetic, geometry, and trigonometry. One important mathematician, Muhammad ibn Musa al-Khwarizmi (around 780–850 CE), wrote a book called Al-Kitab al-Mukhtasar fi Hisab al-Jabr wal-Muqabala. This book laid the foundation for algebra. The word "algebra" actually comes from al-jabr, meaning "completion." Al-Khwarizmi also created step-by-step ways to solve quadratic equations and methods for doing calculations. In fact, the word “algorithm” comes from his name. Another scholar, Omar Khayyam (1048–1131), figured out how to solve cubic equations using geometry. Al-Kashi (died 1429) calculated the number pi to 16 decimal places and improved the way decimal numbers were used, something very important for modern math. In trigonometry, scientists like Al-Biruni and Nasir al-Din al-Tusi made accurate tables for sine, cosine, and tangent, helping to turn trigonometry into its own branch of mathematics.
In medicine, Islamic scientists made great progress by using ideas from ancient Greek thinkers and combining them with careful observation and testing. A famous doctor named Al-Razi (also known as Rhazes, 854–925) wrote a huge 25-volume medical book called Kitab al-Hawi. He was the first to clearly tell the difference between smallpox and measles and believed in learning through watching and testing patients. Another well-known doctor, Ibn Sina (also called Avicenna, 980–1037), combined medical knowledge from Greece, Persia, and India in his book The Canon of Medicine. This book was used as a guide in both Europe and the Islamic world for more than 600 years. He introduced important medical ideas like testing medicines, using quarantine to stop diseases from spreading, checking a patient’s pulse, and understanding how infections work. Muslim doctors also invented surgical tools, used antiseptics to stop infections, and developed special treatments for eye problems. One doctor, Ammar ibn Ali al-Mawsili, even invented a syringe to remove cataracts from the eye.
In the study of light and physics, Ibn al-Haytham (also called Alhazen, 965–1040) made discoveries that helped shape modern science. In his book Book of Optics, he showed that the Greek idea of vision, where light was thought to come out of the eyes, was wrong. He explained that light bounces off objects and goes into the eye, and he correctly described how the retina and lens work. Ibn al-Haytham tested his ideas with experiments using things like mirrors, lenses, and a camera obscura (an early version of a camera). He believed in forming hypotheses, testing them, and repeating experiments. These are ideas that are important to the modern scientific method. He also studied motion, mechanics, and inertia, and his work influenced later scientists in Europe, like Roger Bacon and Kepler.
In early Islamic times, chemistry was called alchemy, and Muslim scientists made big discoveries while trying to understand how materials change. One of the most important alchemists was Jabir ibn Hayyan (also called Geber), who lived in the 8th century. He wrote hundreds of books about how to heat, purify, and mix substances using methods like distillation and crystallization. He even described how to make aqua regia, a powerful acid that can dissolve gold. Jabir believed in testing ideas through careful experiments and recording results, which helped move alchemy closer to real, practical chemistry. He also used special lab tools like alembics (for distilling liquids), crucibles (for heating substances), and furnaces, helping to shape the way modern chemistry labs would work.
Muslim scientists also made great progress in geography, which is the study of the Earth and how it is measured. They traveled, observed nature, and made better maps. A brilliant scholar named Al-Biruni (973–1048) used math and trigonometry to measure the size of the Earth from the top of a mountain, and his answer was very close to what we know today. He also collected the exact locations (latitude and longitude) of over 600 cities and even suggested that the Earth spins, hundreds of years before scientists in Europe did. Another scholar, Al-Khwarizmi, corrected mistakes in older maps from the Greek scientist Ptolemy. Later, Al-Idrisi made a famous world map in 1154 for a European king, using knowledge from Arab traders, sailors, and explorers.
Islamic scientists also made amazing progress in engineering and building machines. They designed clever devices like early robots (called automata), water clocks, and machines that used water and air to move. In the 9th century, three brothers known as the Banu Musa wrote The Book of Ingenious Devices, which described over 100 inventions using gears, valves, and tubes called siphons. Later, a brilliant inventor named Al-Jazari (1136–1206) built fancy water clocks, mechanical toys that could be programmed to move, and one of the first crankshafts, a tool still used in engines today. These machines were not just for show; they were used in palaces, public fountains, and farming systems to help people in everyday life.
To spread knowledge, the Islamic world created many places for learning. These included schools called madrasas, hospitals known as bimaristans, libraries, and observatories where people could study the stars. Famous schools like the Nezamiyeh in Baghdad, Al-Qarawiyyin in Fez (Morocco), and Al-Azhar in Cairo became major centers for science and education. Scholars traveled from place to place, shared ideas, and copied books so they could be studied in different parts of the world. From Spain and North Africa all the way to Central Asia and India, science and learning were an important part of Islamic culture.
Medieval and Renaissance Europe
During the early Middle Ages (around the 5th to 10th centuries), science in Western Europe slowed down after the fall of the Western Roman Empire. Many ancient books and ideas were at risk of being lost. Luckily, monks in monasteries helped save this knowledge by copying old texts written in Latin. These included the works of famous thinkers like Aristotle, Pliny the Elder, Galen, and Boethius. One important scholar from this time was Isidore of Seville (around 560–636), who tried to collect and organize all human knowledge into one big book called Etymologiae. People at the time believed that studying nature helped them better understand God’s creation. Even though science was limited during this period, learning started to improve under Charlemagne (who ruled from 768–814). He supported education and helped start cathedral schools, which taught subjects like math, geometry, music, and astronomy (called the quadrivium), along with grammar, logic, and writing (the trivium).
Between the 11th and 13th centuries, science in Europe came back to life thanks to a big effort to translate ancient books. In places like Spain, Sicily, and parts of the Middle East, European scholars came in contact with the Islamic world and the Byzantine Empire. From them, they got access to many old Greek and Roman ideas, now improved by Arabic scholars. Translators like Gerard of Cremona worked hard to turn important Arabic and Greek books by Aristotle, Avicenna, Alhazen, and Galen into Latin so more people in Europe could understand them. These books taught about astronomy, medicine, math, and optics. This sparked the rise of universities in cities like Bologna, Paris, Oxford, and Salamanca. A new way of thinking called scholasticism became popular. Scholastic thinkers like Thomas Aquinas mixed Greek philosophy with Christian beliefs, and others like Albertus Magnus and Roger Bacon encouraged people to observe nature and do experiments to learn how the world works.
By the 14th century, some smart thinkers in Europe were starting to question old ideas about how things move. Two of these thinkers, Nicole Oresme and Jean Buridan, worked at the University of Paris and had new ideas about physics. Jean Buridan came up with a theory called impetus, which was an early idea similar to what we now call inertia. He said that once something is moving, it can keep moving on its own. It does not need to be pushed forever. This was a big change from the old belief (by Aristotle) that something had to keep being pushed to keep moving. Nicole Oresme did not agree with the old idea that Earth was the center of the universe (geocentric model). He also used graphs to show how things move, which was an early step toward kinematics, the study of motion.
The Renaissance (from the 1300s to the 1600s) was a time when science began to change a lot. People started to focus more on observing nature, doing experiments, and re-reading old science texts from ancient Greece. Scholars like Leonardo Bruni and Marsilio Ficino helped translate these important works so others could study them in more depth. One of the most famous Renaissance thinkers was Leonardo da Vinci (1452–1519). He is known for being a "universal man", or someone who could do many things well. He was an amazing artist, but he also studied anatomy (the human body), how water flows, and how machines work. Leonardo dissected human bodies and made some of the most accurate drawings of muscles, bones, and the heart for his time. He figured out many things about how the vascular system (blood vessels) and body parts worked, even though he never published his findings while he was alive.
A big moment in astronomy happened with a scientist named Nicolaus Copernicus (1473–1543). He suggested a heliocentric model of the universe, which means that the Sun is at the center, not the Earth. This idea was published in his book On the Revolutions of the Heavenly Spheres. In his model, Earth spins every day and goes around the Sun once a year. At the time, most people believed the Ptolemaic model, which said Earth was the center of everything. Even though Copernicus kept some old ideas like epicycles (small loops in orbits), his model was a huge change and led to a new way of thinking about the universe. Another important astronomer was Tycho Brahe (1546–1601). He did not use a telescope, but he made very careful observations of the stars and planets using special instruments. His data was extremely accurate and helped later scientists understand how the planets move.
Johannes Kepler (1571–1630), who used Tycho’s data, discovered three laws of planetary motion. He showed that planets do not move in perfect circles, but in elliptical orbits (oval-shaped). He also found that planets move faster when they are closer to the Sun. Galileo Galilei (1564–1642) combined experiments and astronomy. He used one of the first telescopes to look at the sky and made amazing discoveries. He saw craters on the Moon, sunspots, the phases of Venus, and moons orbiting Jupiter. All these things disproved the old idea that everything revolved around Earth and helped support Copernicus’s heliocentric model. Galileo also studied how objects fall, how pendulums swing, and how things move through the air. He showed that the laws of nature follow math rules, and we can understand them by doing experiments. In 1632, he wrote a book called Dialogue Concerning the Two Chief World Systems that supported heliocentrism. Because of this, he got in trouble with the Catholic Church, which still believed Earth was the center of the universe. Galileo was put on trial and spent the rest of his life under house arrest.
During the Renaissance, there were huge changes in medicine and anatomy (the study of the human body). A scientist named Andreas Vesalius (1514–1564) made a big breakthrough by dissecting real human bodies and studying them carefully. Before this, people mostly followed the ideas of an ancient doctor named Galen, but Vesalius found that Galen had made many mistakes because he studied animals, not humans. Vesalius wrote a book called De humani corporis fabrica (which means On the Fabric of the Human Body), where he corrected hundreds of errors and showed that anatomy should be based on direct observation. This helped make anatomy a real science based on what doctors could see and study for themselves. Later, another important doctor named William Harvey (1578–1657) discovered how blood moves through the body. He showed that the heart pumps blood in a circle, a system called circulation, which was very different from the old idea that blood came from the liver and just moved back and forth. Harvey proved this through experiments and live animal dissection (called vivisection). His work helped change medicine from just guessing and theory to something based on evidence and real body functions.
In math and physics, the Renaissance also saw big advances. A man named Simon Stevin (1548–1620) came up with decimal fractions, which made it easier to do math with numbers. For example, instead of writing 1/10 or 1/100, people could now write 0.1 or 0.01, something used all the time today. René Descartes (1596–1650), a French thinker, invented analytic geometry, which connected algebra with shapes and space. This helped scientists describe the world more clearly using equations. Another important figure was Francis Bacon (1561–1626). He believed science should be based on observation and experiments, not just guessing or using old books. In his book Novum Organum, he explained how scientists should use inductive reasoning, starting with observations and then finding general rules. His ideas became the philosophy of science and influenced many future scientists. Finally, Isaac Newton (1642–1727) brought together the work of earlier scientists like Kepler, Galileo, and Descartes. In the early 1700s, he created a complete system of physics and astronomy that explained how planets move and how objects fall on Earth. His work marked the end of the Renaissance and the start of the Scientific Revolution, a time when modern science truly began.
Age of Enlightenment
The Enlightenment was greatly influenced by the ideas of the Scientific Revolution, especially the work of Isaac Newton (1642–1727). In 1687, Newton wrote a book called Philosophiæ Naturalis Principia Mathematica, where he explained the laws of motion and the law of universal gravitation. He showed that the same force that makes an apple fall also keeps the Moon in orbit around the Earth. Newton also explained that planets move in elliptical (oval-shaped) paths because of gravity. He invented calculus (at the same time as another scientist named Gottfried Leibniz) to help describe things that change, like speed and movement. His experiments with light proved that white light is made up of many colors.
Because of Newton, many Enlightenment thinkers started to use math and science to understand more than just space or motion. In chemistry, Robert Boyle (1627–1691) was an important figure. In his book The Sceptical Chymist (1661), he rejected old ideas from Aristotle and alchemy and introduced new scientific ideas about matter. He discovered Boyle’s Law, which says that when you make a gas container smaller, the pressure goes up (as long as the temperature stays the same). This showed that gases behave in ways that can be measured and predicted. Boyle also believed that science should be based on careful experiments that could be repeated. The move from alchemy (an early, unscientific form of chemistry) to modern chemistry was led by Antoine Lavoisier (1743–1794), who is often called the “father of modern chemistry.” Lavoisier discovered and named the elements oxygen and hydrogen, and he proved that the old phlogiston theory (which said things burned by releasing a strange substance) was wrong. He showed that in a chemical reaction, the total mass stays the same, which is now known as the law of conservation of mass. Lavoisier also created a clear system for naming chemicals, which helped scientists better organize and classify the elements.
In biology and anatomy, scientists during the Enlightenment started to focus more on how living things are organized. Carl Linnaeus (1707–1778) invented the system we still use today for naming living things, called binomial nomenclature. He gave each plant or animal two names, a genus and a species. This helped scientists all over the world talk about the same organisms clearly and consistently. His book, Systema Naturae, first published in 1735, listed and organized thousands of plants and animals and became the foundation of modern taxonomy, the science of classification. At the same time, scientists were learning more about how the human body works. Albrecht von Haller studied things like how nerves work, how muscles move, and how the heart beats. Through experiments, he helped people understand how parts of the body function automatically, without us thinking about them. This was a big step forward in the science of physiology.
During the Enlightenment, astronomy made big advances thanks to better telescopes and the growth of observatories. Edmond Halley (1656–1742) used Newton’s laws to predict when a certain comet would come back. He was right, and that comet is now named Halley's Comet. This showed that gravity could explain how objects move in space. Later, William Herschel (1738–1822) discovered a new planet, Uranus, in 1781. He also found over 2,500 objects in the night sky, like nebulae (clouds of gas and dust) and star clusters. He built some of the biggest telescopes of his time. His work helped scientists realize that the universe is much bigger than just the Milky Way galaxy. Astronomy became more professional, with major observatories in cities like Greenwich, Paris, and Berlin. These places also helped improve navigation, which was important for travel and trade.
Scientific institutions were very important during the Enlightenment. The Royal Society of London (founded in 1660) and the French Academy of Sciences (founded in 1666) brought scientists together to share ideas. They published journals, like Philosophical Transactions, that explained experiments, new discoveries, and theories. These groups helped make science more organized, trustworthy, and easy to understand by others. They also started the idea of peer review, where other scientists check your work. As more people learned to read and write, science started to spread outside of just schools and universities. Salons, coffeehouses, and public lectures became places where people talked about science. Scientists were no longer just private thinkers, they became public figures who shared their knowledge with everyone.
During the Enlightenment, medicine improved because doctors started focusing more on observing patients and learning through hospital training. One important doctor, Giovanni Battista Morgagni (1682–1771), helped create modern diagnosis by showing that symptoms were linked to specific organs, not just to old ideas like imbalances of body fluids. This helped doctors understand that diseases could be traced to problems in certain parts of the body. Another key figure was Edward Jenner (1749–1823), who made the first successful vaccine. He noticed that people who got cowpox did not catch smallpox, a deadly disease. He tested this idea and proved that cowpox could protect people. In 1798, he published his results, starting the science of immunology and vaccination.
During this time, science became more separate from religion and was seen as a way to improve society. Famous thinkers like Denis Diderot, Voltaire, and Jean le Rond d’Alembert believed that science and reason could free people’s minds and make the world better. They worked on a big project called the Encyclopédie (1751–1772), which was like an early encyclopedia. It collected all known scientific and technical knowledge into one place and made it easier for people to learn about how things work, from optics and anatomy to mining and tools. Engineering and technology also made huge progress. James Watt made important changes to the steam engine in the 1760s and 1770s by adding a separate condenser, which made the engine much more efficient. His improvements helped power factories and machines, leading to the Industrial Revolution.
19th Century Science
During the 1800s, science made big changes, especially in how we understand heat, energy, electricity, and atoms. In the study of heat and energy, thermodynamics, scientists created the laws of thermodynamics. These laws helped people understand how steam engines work and how to make them more efficient. In 1824, a scientist named Sadi Carnot came up with the idea of the Carnot cycle, which showed that an engine’s efficiency depends on the temperature difference between where the heat comes from and where it goes. This idea helped lead to the second law of thermodynamics, which explains how energy spreads out. Later, Rudolf Clausius introduced the idea of entropy, which measures how energy becomes more disordered over time. Scientists William Thomson (Lord Kelvin) and James Prescott Joule created the first law of thermodynamics, which says that energy cannot be created or destroyed, only changed from one form to another.
In electricity and magnetism, scientists discovered that these two forces are connected. Michael Faraday, in the 1830s and 1840s, did experiments that showed how moving magnets can create electricity, a process called electromagnetic induction. This discovery is what makes electric generators and transformers work. Faraday also came up with the idea of fields, which are invisible areas where electric or magnetic forces can act. Later, in the 1860s, James Clerk Maxwell built on Faraday’s work and wrote four equations, called Maxwell's equations, that explain how electric and magnetic fields move and interact. These equations also predicted the existence of electromagnetic waves, which led to the invention of things like radios, TVs, and wireless communication.
At the beginning of the century, John Dalton brought back the idea of atomic theory. He said that every element (like oxygen or iron) is made up of its own kind of atom, and these atoms combine in fixed amounts to make compounds (like water or carbon dioxide). His ideas helped explain important chemistry rules, like the law of multiple proportions, which says that elements always combine in certain number patterns. Later, in 1869, Dmitri Mendeleev created the periodic table. He arranged the elements in order by atomic mass and grouped them by chemical properties. Mendeleev’s table was so smart that it even predicted new elements, like gallium and germanium, before they were discovered. When scientists later found these elements and they matched his predictions, it showed that the periodic law was a powerful way to understand and organize chemistry.
Meanwhile, biology was also changing in a major way. In 1859, Charles Darwin published a book called On the Origin of Species. In it, he explained his theory of evolution by natural selection. Darwin said that living things change over time. These changes happen because of small differences that are passed from parents to offspring. If a trait helps an organism survive and have more babies, that trait becomes more common over generations. This is how new species can form. Darwin got many of his ideas by observing animals and plants during his long trip on the ship HMS Beagle. He was also influenced by Thomas Malthus, who wrote about how populations grow, and Charles Lyell, who studied how the Earth changes slowly over time. Darwin’s theory replaced older ideas that species never change. It gave scientists a new way to understand life, one that was based on evidence, change, and history. It also started many important discussions about science, religion, and philosophy.
At the same time as other big discoveries in the 1800s, scientists also developed the cell theory, which says that all living things are made of cells, and that the cell is the basic unit of life. This idea was first introduced in the 1830s by Matthias Schleiden and Theodor Schwann. Later, Rudolf Virchow added that all cells come from other cells, which he summed up in the Latin phrase "omnis cellula e cellula". The invention and improvement of the light microscope helped scientists look more closely at cells. They were able to discover important parts inside cells, like the nucleus, mitochondria, and other tiny structures called organelles. These discoveries helped build the foundation for molecular biology and genetics, which study how cells work and how traits are passed down.
In medicine, the 1800s were a turning point as it began to become more scientific. This progress was made thanks to new knowledge in disease research, germs, surgery, and public health. One of the most important scientists was Louis Pasteur. He showed that tiny organisms (microbes) can cause disease and spoil food. This idea became known as the germ theory of disease. Pasteur proved that germs do not just appear out of nowhere (a belief called spontaneous generation). He also invented vaccines for rabies and anthrax, and created pasteurization, a method to heat food and drinks to kill harmful microbes and keep them from spoiling. Another important scientist was Robert Koch. He discovered the specific bacteria that cause tuberculosis, cholera, and anthrax. Koch also created new lab methods, like using agar plates to grow bacteria and staining techniques to make microbes easier to see under a microscope. He developed Koch’s postulates, a set of rules that scientists use to prove that a certain germ causes a specific disease.
In the 1840s, doctors began using anesthesia, like ether and chloroform, to perform pain-free surgeries. This was a huge breakthrough because it allowed surgeons to do more complex operations without hurting the patient. Around the same time, Joseph Lister started using carbolic acid (also called phenol) to clean wounds and tools, which greatly reduced the number of people who died from infections after surgery. His work helped start the use of antiseptic techniques in hospitals and led to the modern idea of clean, germ-free medical care. Because of these changes, hospitals became places of real healing and science, not just places where the sick were kept. At the same time, big cities were facing many diseases due to crowding and pollution from the Industrial Revolution. This led to early public health reforms. One important figure was Florence Nightingale, who worked during the Crimean War. She pushed for clean hospitals, better nursing, and proper training, which helped improve medical care all over the world.
In the study of geology, scientists began to understand that Earth is very old, much older than people once believed. Charles Lyell wrote a famous book called Principles of Geology (1830–1833), where he explained that natural processes like erosion (wearing down of land) and sedimentation (building up of layers) happen slowly and steadily over a long time. This idea is called uniformitarianism. Lyell’s work was important because it challenged the biblical view that Earth was only a few thousand years old. It also gave Charles Darwin the long time span needed for his theory of evolution to work. Other areas of geology, like stratigraphy (studying rock layers) and fossil correlation (matching fossils to different layers), helped scientists piece together Earth’s history. Studies in mineralogy (minerals) and paleontology (fossils) also helped explain what the Earth is made of and what life used to be like.
During the 19th century, people began to study human behavior and society in a more scientific way. This was the beginning of the social sciences. A thinker named Auguste Comte came up with the idea of positivism, which said that we should study society using facts and observations, just like scientists study nature. This led to the creation of sociology, a field that tries to understand how things like cities, factories, and social classes affect people’s lives. In economics, early ideas from Adam Smith were built upon by other thinkers like David Ricardo, Thomas Malthus, and John Stuart Mill. They used math and statistics to study how money, jobs, and resources are shared in society. 
At the same time, science became more organized in every area. Countries created national science academies and professional journals where scientists could publish and share their discoveries. Universities and research institutes trained new scientists, and governments or private groups started to fund science projects. Science also became something the public could enjoy and learn about. Museums and big events like the Great Exhibition of 1851 in London showed off new inventions and discoveries, proving that science was important for progress. Some amazing inventions of the time included the telegraph (for long-distance communication), the steamship, the electric light, and photography. These changes showed how science could improve daily life and move society forward.
20th and 21st Century Science
At the start of the 20th century, scientists realized that the old ideas of physics (called classical mechanics) could not fully explain how very small things (like atoms) or very large things (like galaxies) work. This led to the birth of modern physics. In 1905, a young scientist named Albert Einstein wrote four important papers that changed science forever. One of these introduced the special theory of relativity, which showed that time and space are not fixed. Instead, time can slow down and lengths can shrink when objects move very fast, close to the speed of light. He also came up with the famous equation E = mc², showing that mass and energy are two forms of the same thing. Later, in 1915, Einstein created the general theory of relativity, which explained gravity in a new way. Instead of thinking of gravity as a pulling force, he said that mass bends spacetime, and this bending is what is felt as gravity. This idea helped scientists understand things like black holes, gravitational lensing (how light bends around stars), and how the universe is expanding.
At the same time, a different kind of physics called quantum mechanics was being developed to understand how things work at the level of atoms and tiny particles. In 1900, Max Planck said that energy comes in small amounts, called quanta. Niels Bohr created a model of the atom where electrons move in specific orbits, helping to explain how atoms give off light. Werner Heisenberg and Bohr developed the Copenhagen interpretation, which included the uncertainty principle. This says we cannot know exactly where a particle is and how fast it is moving at the same time. Erwin Schrödinger came up with wave mechanics, which showed how particles can also act like waves. Paul Dirac combined quantum theory with Einstein’s ideas and predicted the existence of antimatter. These discoveries helped create many modern technologies, like semiconductors (used in computers), lasers, nuclear power, and even the new field of quantum computing.
In the 20th century, a new area of science called nuclear physics became very important and had a big impact on the world. It started when Henri Becquerel discovered radioactivity, and Marie and Pierre Curie studied it further. They learned how atoms can break apart in a process called atomic decay. In 1938, scientists Otto Hahn and Fritz Strassmann discovered something called nuclear fission, which is when the nucleus of an atom splits, releasing a huge amount of energy. Lise Meitner and Otto Frisch explained how it worked. This discovery led to the creation of the Manhattan Project, a secret program where scientists like Enrico Fermi and J. Robert Oppenheimer developed the first atomic bomb, which was used in World War II in 1945. But nuclear physics was not just used for weapons. It also led to the development of nuclear power plants, which generate electricity, and medical technologies like PET scans (used to see inside the body) and radiation therapy (used to treat cancer).
Meanwhile, in biology, scientists began to understand how traits are passed from parents to children. This started with the rediscovery of Gregor Mendel’s laws of inheritance, which led to the science of genetics. In 1953, James Watson and Francis Crick, using X-ray images from Rosalind Franklin and Maurice Wilkins, discovered the double helix structure of DNA. This showed how genetic information is stored in the sequence of nucleotides (the building blocks of DNA). This discovery led to molecular biology, which helped scientists understand how genes make proteins and how certain diseases are caused by genetic problems. Later, a huge international project called the Human Genome Project finished in 2003. Scientists mapped out all the DNA in a human, which includes over 3 billion base pairs and more than 20,000 genes. This started the field of genomics, and helped create new ways to study and treat diseases through personalized medicine and bioinformatics (the use of computers in biology).
Biotechnology in the late 1900s and early 2000s gave scientists amazing new tools to work with DNA and genes. These included Recombinant DNA technology which lets scientists combine DNA from different sources. PCR (polymerase chain reaction) is a method to quickly make millions of copies of a piece of DNA. CRISPR-Cas9, on the other hand, is a tool that lets scientists edit genes very precisely, like using scissors to cut and change DNA. These tools are now used in many ways. To create genetically modified crops, make medicines like insulin, perform gene therapy to treat diseases, and do quick and accurate disease testing. In medicine, a huge breakthrough came in 1928, when Alexander Fleming discovered penicillin, the first antibiotic. This completely changed how bacterial infections were treated and saved millions of lives. Later, vaccines were developed for deadly diseases like polio, measles, and HPV. More recently, mRNA vaccines (like some COVID-19 vaccines) have helped fight new diseases and protect public health around the world.
At the same time, information technology and computer science became a big part of science and everyday life. During World War II, the first electronic computers, ENIAC and Colossus, were built. Alan Turing created early ideas about how computers work and also helped crack secret codes during the war. In 1947, three scientists at Bell Labs, Bardeen, Brattain, and Shockley, invented the transistor, a tiny part that made it possible to build smaller and faster electronic devices. This led to the microprocessor and started the digital revolution. Later, scientists created the internet, which began as a government project called ARPANET. The internet grew into a huge, worldwide system that allows people to communicate, learn, shop, and share information.
Space science made huge leaps forward in the 20th century as humans began to explore beyond Earth for the first time. In 1957, the Soviet Union launched Sputnik 1, the first artificial satellite. Then, in 1961, Yuri Gagarin became the first human in space. One of the biggest milestones came in 1969, when NASA’s Apollo Program sent Neil Armstrong and Buzz Aldrin to the Moon, making them the first people to walk on the Moon. Robots also helped us explore space. The Voyager probes, launched in 1977, sent back amazing information about the outer planets and are still traveling through interstellar space (the space between stars). In 1990, the Hubble Space Telescope was launched into orbit. It took detailed pictures of galaxies, nebulae, and supernovae, helping scientists learn more about the expanding universe. In the 21st century, space exploration has kept growing. NASA’s Mars rovers explore the Red Planet. Space telescopes like Kepler and TESS search for exoplanets (planets around other stars). Private companies like SpaceX and Blue Origin are working on things like Mars missions and even space tourism.
At the same time, climate and environmental science became very important. Back in 1896, scientist Svante Arrhenius said that carbon dioxide (CO₂) in the air could raise Earth’s temperature. This is called the greenhouse effect. By the late 1900s, scientists had strong evidence that human activities, like burning fossil fuels, were changing the climate. They got this data from things like ice cores, satellites, and ocean studies. Today, scientists around the world work together through groups like the Intergovernmental Panel on Climate Change (IPCC) to study climate change and warn about its dangers. They say it is urgent to reduce CO₂ emissions to protect the planet. To help with this, we now use tools like climate models, remote sensing (using satellites to study Earth), and renewable energy (like solar and wind power) to fight climate change and find better ways to live sustainably.
Neuroscience and cognitive science are the sciences that study the brain and how we think, feel, and make decisions. In recent years, scientists have made big discoveries thanks to new brain scanning tools like fMRI and PET scans, which show real-time images of brain activity. These tools helped researchers find out that the prefrontal cortex (the front part of the brain) is important for decision-making, and the amygdala (a small part deep in the brain) helps process emotions like fear and anger. Today, scientists are trying to map all the connections in the brain. This is called connectomics. Also, brain-computer interfaces have been developed. These allow people who are paralyzed to move robotic arms or prosthetic limbs using only their brain signals. At the same time, fields like artificial intelligence (AI) and machine learning, which used to be mostly theory, are now real tools. They help with things like voice assistants, face recognition, medical diagnoses, and self-driving cars.
In the 21st century, scientists from different fields began working together more closely, creating powerful new areas of research. These include nanotechnology (the science of building tiny machines and materials at the scale of atoms and molecules), synthetic biology (designing and creating new living systems, such as bacteria that produce medicine), quantum information science (using the strange laws of quantum physics to make ultra-powerful computers), and systems biology (studying how all the parts of a living system work together). One of the biggest science projects of this century was at CERN, where scientists used the Large Hadron Collider (LHC), a huge machine that smashes particles together, to discover the Higgs boson in 2012. This particle helps explain how other particles get mass and is a key part of the Standard Model of physics. Scientists are also still trying to solve big mysteries like dark matter, dark energy, and how to unite quantum physics with gravity, which could lead to a unified theory of everything in the universe.
Branches
Natural sciences
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  The natural sciences seek to understand how the world and universe around us works. There are five major branches, indicated by the photos above taken clockwise from top left: astronomy, chemistry, Earth science, biology, and physics.
Natural sciences are a major area of science that focuses on understanding the natural world. Scientists in this field study how things in nature work by watching carefully, doing experiments, and creating models or theories. These models help explain why things happen and can even predict what might happen next. Natural sciences depend on evidence that can be seen, measured, and repeated. Scientists use the scientific method, which means they make guesses (called hypotheses), test them through experiments, and change their ideas if the results do not match. This process helps make sure that scientific conclusions are as accurate as possible.
There are several main areas of natural science, including physics, chemistry, biology, earth sciences, and astronomy. Each area focuses on different parts of nature, but they often work together in today’s research. Physics is the study of matter, energy, and the forces that affect them. Physicists explore everything from the tiniest particles, like electrons and quarks, to giant objects like stars and galaxies. They use different theories depending on the scale. Quantum mechanics for tiny particles and general relativity for huge cosmic objects. Physics has led to important laws and ideas that help explain the universe, such as Newton's laws of motion, the laws of thermodynamics, Maxwell's equations for electricity and magnetism, and the Standard Model, which organizes the basic building blocks of matter.
Chemistry is often called the central science because it connects physics and biology. It focuses on what matter is made of, how it is structured, how it behaves, and how it changes during reactions. Chemists study atoms and molecules to understand how they bond together, break apart, and move energy during chemical changes. Chemistry is divided into different areas. Organic chemistry studies compounds that contain carbon (like living things do). Inorganic chemistry looks at compounds without carbon. Physical chemistry explores how chemistry and physics work together. Analytical chemistry focuses on measuring and identifying substances. Biochemistry applies chemistry to biological systems like cells and DNA. Because of chemistry, there are drugs, plastics, batteries, fertilizers, and many other useful materials and tools.
Biology is the science of living things. It explores how organisms are built, how they work, how they grow, where they come from, and how they change over time. Biology includes many branches, such as cell biology (which studies the basic units of life, cells), genetics (which looks at heredity and DNA), ecology (which studies how organisms interact with each other and the environment), evolutionary biology (which looks at how life has changed over millions of years), and molecular biology (which focuses on life at the smallest scales, like proteins and genes). Biologists use tools like microscopes, DNA sequencing, and gene editing to explore life. Biology is important in health, farming, nature protection, and biotechnology, helping us make vaccines, improve crops, and protect endangered species.
Earth sciences, also called geosciences, are the sciences that study the Earth and everything that affects it. This includes the solid ground, the atmosphere (air and weather), the hydrosphere (water and oceans), and the biosphere (all living things). Earth scientists use ideas from physics, chemistry, and biology to understand how Earth’s systems work together. Earth sciences include geology, which looks at the layers of the Earth, rocks, and the history of the planet; meteorology, which studies weather and the atmosphere; oceanography, which focuses on oceans and sea life; and climatology, which examines long-term climate patterns and how they change. These studies are important for learning about natural disasters like earthquakes, volcanoes, and hurricanes, and for helping us manage natural resources and protect the environment.
Astronomy is the science that studies space, planets, stars, galaxies, and the universe. Astronomers observe the sky using telescopes and use theories and math to understand what they see. Modern astronomy is closely connected to physics, especially in a branch called astrophysics, which uses physical laws to explain how space objects behave. Astronomy has helped us discover just how huge the universe is and that there are other solar systems beyond our own. Scientists study amazing objects in space like black holes, neutron stars, and dark matter, a mysterious substance that we cannot see directly. Astronomy also helps us explore big questions, like where the universe came from, how it has changed over time, and what might happen to it in the future.
The natural sciences all use similar methods to learn about the world. First, scientists use empirical observation, which means they carefully collect data using tools or by studying things in nature. They also do experiments, where they test ideas in controlled settings to see what happens. Another method is mathematical modeling, where scientists use math and computers to describe and predict how things work. To make sure results are trustworthy, scientists follow rules like peer review (where other experts check their work), reproducibility (so others can repeat the experiment), and falsifiability (the idea that scientific claims must be testable and could be proven wrong). Scientists use numbers and statistics to support their conclusions with solid, unbiased evidence.
Today, the natural sciences often combine different subjects to solve big problems. These mixed areas are called interdisciplinary fields, like biophysics (biology + physics), astrochemistry (astronomy + chemistry), geobiology (geology + biology), and climate science (which combines many fields). These new fields help scientists understand complex challenges, such as climate change, disease outbreaks, clean energy, and space exploration. For example, studying the climate means using knowledge from physics, chemistry, biology, and computer modeling. Scientists in astrobiology use ideas from space science, chemistry, and biology to search for life on other planets.
The natural sciences have led to amazing technology and discoveries that have changed our lives. Physics helped create nuclear energy, computers, and electronics. Chemistry made new medicines, better farming products, and useful materials like plastics. Biology and medicine led to vaccines, treatments for genetic diseases, and ways to grow or repair body parts. Earth science helps us predict natural disasters and take care of the environment. Astronomy has led to better telescopes, cameras, and even new ways to process big data. Finally, the natural sciences are very important for education, government, and solving world problems. Understanding science helps people make smart choices about things like global warming, health, and new technology. Governments use science to make rules, spend money wisely, and protect people and nature. Many big science projects, like CERN (which studies tiny particles), the IPCC (which studies climate change), or the Human Genome Project (which mapped all human genes), show how countries and scientists work together around the world to learn and make progress.
Core Principles and Characteristics
Empiricism
Empiricism is a basic idea in science. It says that we learn things by using our senses, like seeing, hearing, or measuring, not just by guessing or following tradition. Instead of relying only on what people believe or think is true, science depends on what we can actually observe, test, and measure. This is why scientists use special tools like telescopes, microscopes, and sensors, to help them see things that are too small, too far, or otherwise invisible to the human eye. For example, when scientists look for planets outside our solar system, called exoplanets, they cannot see the planets directly. Instead, they look at tiny changes in the brightness of a star. If the star gets a little dimmer at regular times, it might mean a planet is passing in front of it. This method is based on careful observation, which is what empiricism is all about.
Empiricism also means that scientific results should be reproducible. This means that if someone does an experiment again, they should get the same results. A good example is Gregor Mendel’s pea plant experiments, where he discovered how traits are passed down from parents to offspring. Scientists were able to repeat his work and get the same patterns, showing that the results were reliable. The idea of empiricism was supported by philosophers like John Locke, who believed that people are not born with knowledge. Instead, he said the mind starts out like a blank slate, and everything we learn comes from experience. This idea is different from rationalism, which says we are born with certain ideas or that we can learn everything through logic alone. In science, empiricism helps make sure our knowledge is based on real-world evidence.
Empirical methods in science are not just about watching things happen, they also include doing careful experiments to test ideas. These experiments are done in a controlled way to help scientists figure out which things cause certain results. For example, when Alexander Fleming saw that a certain type of mold killed bacteria, it was not enough just to notice it. Scientists had to do more experiments to prove that the mold, later called Penicillium notatum, could really fight infections. This led to the discovery of penicillin, an important medicine. This kind of testing is how scientists confirm what works and what does not. Galileo also used experiments with ramps (inclined planes) to show that objects do not need a force to keep moving, which went against the old ideas from Aristotle. In more recent times, scientists used special detectors at LIGO to find gravitational waves, tiny ripples in space predicted by Einstein’s theory of general relativity 100 years earlier. This discovery was another example of how scientists use careful observation and testing to confirm or disprove scientific theories. Empirical methods are also used in big, complex areas like climate science. Scientists collect information from things like ice cores, satellites, and even tree rings to learn about Earth’s climate over time. These different sources of data help build models to understand and predict how the planet is changing.
Even though empiricism, the idea that knowledge comes from observation and experience, is a key part of science, it is not always simple. One challenge is deciding what counts as a valid observation and how to understand what we see. Sometimes, what scientists notice or pay attention to depends on the theories they already believe in. This idea is called “theory-laden observation.” Philosopher Thomas Kuhn explained that scientists often use models or ideas they already have to decide what to look for and how to explain it. For example, early astronomers had trouble understanding why planets sometimes seemed to move backward in the sky (called retrograde motion) until they used models like the Ptolemaic system or the later Copernican model, which helped them interpret what they were seeing. In some parts of science, such as quantum physics, things get even harder. Scientists cannot always observe tiny particles directly. Instead, they have to use mathematical models and experiments to figure out what is happening. Phenomena like quantum entanglement or wavefunction collapse are known through indirect evidence and complex data. In the social sciences (like psychology or sociology), empiricism works a bit differently. Scientists use tools like surveys, interviews, and experiments with people to gather data. But this kind of research can have its own problems. For example, people might give answers they think are expected (this is called social desirability bias), or they might act differently because they know they are being watched (called the Hawthorne effect or observer bias).
Rationality and Logic
Rationality and logic are very important in science. They help scientists make sure their ideas make sense, their theories fit together, and their conclusions are based on good reasoning. Rational thinking in science means using reason carefully. Scientists use it to come up with ideas (called hypotheses), to plan experiments, to understand results, and to compare different explanations. This helps make sure that conclusions come from real evidence, not just guesses. Logic gives rules for how to go from one idea to another. It helps scientists check if their arguments are valid. For example, in biology, if all mammals are warm-blooded and whales are mammals, then whales must be warm-blooded. This is a basic kind of logical thinking called deductive reasoning. Science also uses the rule of non-contradiction. This means something cannot be both true and not true at the same time. For example, a chemical cannot both contain and not contain the same element under the same conditions. This helps scientists make clear and reliable chemical models. There are also formal types of logic, like propositional logic, predicate logic, and modal logic. These are used in areas like computer science, artificial intelligence, and mathematical biology. They help scientists build computer programs, design experiments, and understand complex systems.
Logic and rational thinking are important in science not just to support good ideas, but also to find mistakes, hidden problems, or wrong assumptions in scientific theories. In physics, the discovery of quantum mechanics made scientists question old ideas. For example, classical physics said that objects behave in clear, predictable ways (called determinism) and that things far apart cannot affect each other instantly (called locality). But quantum mechanics showed that very small particles often behave in strange and random ways, so scientists had to use new kinds of logic to understand them. There is also a big problem between two important theories: general relativity and quantum field theory. Relativity explains how big things like planets and galaxies work, while quantum theory explains tiny particles. But the two theories do not fully agree with each other. This has led scientists to search for a new theory that combines both, such as string theory or loop quantum gravity. Science often uses a method called hypothetico-deductive reasoning. This means scientists start with a theory, then use logic to make predictions that can be tested. If experiments agree with the prediction, the theory is stronger. If not, the theory may need to change. For example, we know that antibiotics kill bacteria, not viruses. This logical idea helps doctors avoid giving antibiotics for viral infections, which helps prevent antibiotic resistance. In social sciences, logic is also important. Game theory is a tool that uses logic and reasoning to study how people make choices in situations where others are also making decisions. It helps explain things like voting, diplomacy between countries, and even how governments sell licenses for things like radio frequencies. Game theory helps people make better decisions by thinking logically about the actions of others.
Scientific thinking also includes the idea of parsimony, which is often called Occam's Razor. This idea says that if there are different explanations for something, the simplest one that still explains the facts should be chosen. This rule helps scientists choose the best theories in many fields, such as biology and climate science. For example, a long time ago, people believed that the Earth was at the center of the universe (the geocentric model). But this model needed many complicated parts, like epicycles, to explain how planets moved. Later, Copernicus suggested that the Sun was at the center instead (the heliocentric model). This simpler idea explained the same facts more easily, so it became the better choice. In brain science, a new idea called the Bayesian brain hypothesis says that the brain works by using probability to update what it believes. This means the brain uses logic and evidence, like a smart guesser. This idea is also used in computer fields like robotics and machine learning. Logic is also very important in doing science in a fair and careful way. For example, decision theory is a part of logic that helps scientists decide how to run medical studies. It helps them think clearly about risks, benefits, and what is unknown when testing new treatments.
 Scientific method 
Today, "science" usually refers to a way of pursuing knowledge, not just the knowledge itself. It is mainly about the phenomena of the material world. The Greek works into Western Europe from the 6th to 7th century B.C. revived "Philosophy". In the 17th and 18th centuries scientists increasingly sought to formulate knowledge in terms of laws of nature such as Newton's laws of motion. And during the 19th century, the word "science" became more and more associated with the scientific method itself. It was seen as a way to study the natural world, including physics, chemistry, geology and biology.
It was also in the 19th century that the term scientist was created by William Whewell. He meant it to tell the difference between those who looked for knowledge on nature from those who looked for other types of knowledge.
The scientific method is the name given to the methods used by scientists to find knowledge. The main features of the scientific method are:
 Scientists identify a question or a problem about nature. Some problems are simple, such as "how many legs do flies have?" and some are very deep, such as "why do objects fall to the ground?"
 Next, scientists investigate the problem. They work at it, and collect facts. Sometimes all it takes is to look carefully.
 Some questions cannot be answered directly. Then scientists suggest ideas, and test them out. They do experiments and collect data.
 Eventually, they find what they think is a good answer to the problem. Then they tell people about it.
 Later, other scientists may agree or not agree. They may suggest another answer. They may do more experiments. Anything in science might be revised if we find out the previous solution was not good enough.
 An example 
A famous example of science in action was the expedition led by Arthur Eddington to Principe Island in Africa in 1919. He went there to record where the stars were around the Sun during a solar eclipse. The observation of where the stars were shown that the apparent star positions close to the Sun were changed. In effect, the light passing the Sun was pulled towards the Sun by gravitation. This confirmed predictions of gravitational lensing made by Albert Einstein in the general theory of relativity, published in 1915. Eddington's observations were considered to be the first solid proof in favour of Einstein's theory.
 Practical impacts of scientific research 
Discoveries in fundamental science can be world-changing. For example:
{| class="wikitable" style="font-size:90%"
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! Research !! Impact
|-
| Static electricity and magnetism (1600)Electric current (18th century) || All electric appliances, dynamos, electric power stations, modern electronics, including electric lighting, television, electric heating, magnetic tape, loudspeaker, plus the compass and lightning rod.
|-
| Diffraction (1665) || Optics, hence fiber optic cable (1840s), cable TV and internet
|-
| Germ theory (1700) || Hygiene, leading to decreased transmission of infectious diseases; antibodies, leading to techniques for disease diagnosis and targeted anticancer therapies.
|-
| Vaccination (1798) || Leading to the elimination of most infectious diseases from developed countries and the worldwide eradication of smallpox.
|-
| Photovoltaics (1839) || Solar cells (1883), hence solar power, solar powered watches, calculators and other devices.
|-
| The strange orbit of Mercury (1859) and other researchleading to special (1905) and general relativity (1916) || Satellite-based technology such as GPS (1973), satnav and communications satellites.
|-
| Radio waves (1887) || Used in broadcast: radio (1906) and television (1927) entertainment. It is used in telephony, emergency services, radar (navigation and weather forecasting), medicine, astronomy, wireless communications, and networking. Radio research led to microwave cooking.
|-
| Radioactivity (1896) and antimatter (1932) || Cancer treatment (1896), Radiometric dating (1905), nuclear reactors (1942) and weapons (1945), PET scans (1961), and medical research (with isotopic labelling)
|-
|X-rays (1896)|| Medical imaging, including computer tomography
|-
| Crystallography and quantum mechanics (1900) || Semiconductor devices (1906), hence modern computing and telecommunications including the integration with wireless devices: the mobile phone
|-
|Plastics (1907)||Starting with bakelite, many types of artificial polymers for numerous applications in industry and daily life
|-
|Antibiotics (1880's, 1928) || Salvarsan, Penicillin, doxycycline. In 2018 Amoxicillin and amoxicillin/clavulanic acid were the most frequently used.
|-
|Nuclear magnetic resonance (1930's) || Nuclear magnetic resonance spectroscopy (1946), magnetic resonance imaging (1971), functional magnetic resonance imaging (1990's).
|-
|Genomics (1990s)||Genomics = genetics + medicine. It is the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA (or RNA). This makes up its genes. Vaccines for viruses are built by genomics.
|}
Philosophy of science
The philosophy of science is a subject that looks closely at how science works and what it really means. It asks big questions like: How do we know something is true in science? How do scientific ideas change over time? Can science truly be objective? People who study the philosophy of science try to understand the methods scientists use, the rules they follow, and how their discoveries affect the world. This field connects to other areas of philosophy, such as epistemology (the study of knowledge), metaphysics (the study of what exists), ethics, and logic. It also looks at how science is actually done in both natural sciences (like physics and biology) and social sciences (like psychology and sociology).
One of the biggest questions in the philosophy of science is called the demarcation problem. This means trying to figure out what counts as real science and what does not, like pseudoscience, which pretends to be scientific but doesn't follow the same rules. A famous philosopher named Karl Popper said that real science should be falsifiable. This means a scientific idea must make clear predictions that could be proven wrong with evidence. For example, Einstein’s theory of general relativity predicted that light would bend during a solar eclipse. Scientists tested this and confirmed it, showing the theory was falsifiable. On the other hand, Popper criticized things like Freud’s psychoanalysis, which tried to explain human behavior in ways that could not really be tested or proven wrong, because it could twist its explanations to fit any situation. Some later philosophers, like Imre Lakatos and Paul Feyerabend, said that science is not always so simple. They pointed out that many great scientific ideas started out as vague or hard to test. So, the question of what counts as real science is still debated, and there may not be one easy answer.
Scientific realism and anti-realism are two different ways of thinking about what science is really doing. People who support scientific realism, like Hilary Putnam and Richard Boyd, believe that scientific theories describe the world as it actually is, even the parts we cannot see, like electrons or black holes. They argue that science works so well, like making accurate predictions and helping us build amazing technology, because its ideas are mostly true, or at least close to the truth. On the other side, anti-realists, like Bas van Fraassen, believe something different. They say the job of science is not to find the absolute truth, but to come up with ideas and models that correctly predict what we can observe. This is called empirical adequacy. For example, in quantum mechanics (the science of very tiny particles), the math can predict things very well, but different scientists have totally different beliefs about what is really happening. Some realists believe in things like the Many-worlds Interpretation, while anti-realists prefer ideas like the Copenhagen Interpretation, which focus only on what we can measure and see.
Another big idea in the philosophy of science is how science explains things. One early idea was the deductive-nomological model, created by Carl Hempel. He said that to explain something scientifically, you had to show how it follows from general laws and starting conditions. For example, explaining why a planet moves in an ellipse (oval shape) using Newton's laws of gravity and motion. But not everyone agreed with this model. Some philosophers thought it did not explain things in everyday life or in complicated sciences like biology. So, newer thinkers, like Nancy Cartwright and James Woodward, introduced different ways to explain things, especially using causes and mechanisms. In this newer view, a good explanation tells us how something works step by step. For instance, if we want to explain how the heart pumps blood, we do not just give a law, we show how parts like pacemaker cells, ion channels, and muscle fibers all work together to make the heart beat. This kind of explanation is especially useful in subjects like neuroscience and medicine, where understanding the parts and how they interact is key.
One big question in the philosophy of science is called the problem of induction. This idea was first brought up by a philosopher named David Hume in the 1700s. He asked: How do we really know that what happened in the past will keep happening in the future? For example, we believe the sun will rise tomorrow because it has always done so. But Hume pointed out that we do not have a perfect reason to believe that, just past experience. Science often depends on these kinds of patterns, but there is no absolute proof that they will always hold true. Later on, a philosopher named Nelson Goodman added to this puzzle. He showed that it is not always easy to decide which patterns are meaningful. He created a strange example using the color “grue,” which means something is green before a certain time and blue after. This example showed that choosing which patterns to trust is harder than it seems. Today, some philosophers and scientists try to solve this problem using probability. This is called Bayesian reasoning, where people adjust their beliefs based on how likely something is and what they already know. But even this method has challenges, like being hard to calculate and including some personal judgment.
Another important thinker was Thomas Kuhn, who wrote a famous book in 1962 called The Structure of Scientific Revolutions. He said that science does not always grow in a straight line by slowly adding new facts. Instead, he said science works through paradigms, big ideas or frameworks that shape how scientists think, what they study, and what evidence they trust. Scientists work within a paradigm for a long time during “normal science,” but eventually they find anomalies, things that do not fit. When enough of these build up, a scientific revolution happens, and the old paradigm is replaced with a new one. For example, when scientists moved from Newton’s laws to Einstein’s theory of relativity, or from Ptolemy’s geocentric model (Earth at the center) to Copernicus’s heliocentric model (Sun at the center), these were paradigm shifts. Kuhn also said that different paradigms can be incommensurable, meaning they are so different that they cannot easily be compared. This idea was controversial. Philosophers like Karl Popper and Imre Lakatos disagreed with Kuhn. Karl Popper, for example, believed that science moves forward by falsification. This means that scientists should constantly test their ideas and try to prove them wrong. If a theory fails the test, it should be rejected. Popper thought that a good scientific theory must be one that could be proven false if the evidence does not support it. For example, saying “All swans are white” is a scientific idea because it can be tested, and even disproven by finding just one black swan. Another philosopher, Imre Lakatos, offered a different view. He did not think science was as dramatic as Kuhn’s idea of sudden "paradigm shifts," but he also did not fully agree with Popper. Lakatos said that science works through research programmes, groups of theories and ideas that develop over time. These programmes may face problems and make mistakes, but if they keep improving and helping us understand more, then they are still making progress. Lakatos believed science should still be rational and goal-directed, even if it changes slowly and builds on earlier ideas.
The philosophy of science does not just focus on how we know things or what reality is made of. It also asks important questions about ethics (what is right or wrong) and politics (how science affects society). These questions are especially important in fields like environmental science, artificial intelligence, biotechnology, and how we respond to pandemics. For example, when scientists or governments use computer models to make decisions about public health or climate change, philosophers ask: Are these models reliable? Are they being used fairly? Scientists also have to think about responsibility, how their discoveries might help or harm people. One idea that comes up is called the precautionary principle. This means that if a new technology might be dangerous and we do not fully understand the risks, we should be careful and not rush into using it. This idea is based on epistemic humility, which means recognizing the limits of our knowledge. A good example is CRISPR, a powerful gene-editing tool. While it can be used to treat diseases, it also raises big questions: Should we change human DNA? Should we allow “designer babies”? These are not just scientific questions, they are philosophical and ethical ones, too.
Philosophers also talk about whether there is only one correct way to do science. Some thinkers, like Paul Feyerabend, believed that there is no single method that all science must follow. He called this idea epistemological anarchism, which means that even unusual or untraditional approaches can lead to progress. This way of thinking is called pluralism, and it accepts that different fields of science may need different tools and ways of thinking. For instance, in climate science, scientists use a mix of physics, statistics, and information about human behavior to make predictions. In medicine, both controlled experiments and patient stories give useful, but very different, kinds of evidence. This shows that science does not always follow just one path. Instead, different methods can work together to give us a better understanding of the world.
Science and society
Scientific discoveries have played a big role in changing the world. They have helped improve how people live, work, and communicate. Some important examples include the invention of the printing press, the rise of factories during the Industrial Revolution, and modern tools like electricity, antibiotics, and the internet. These discoveries changed not only technology, but also how societies are organized. For example, in the 1700s, James Watt improved the steam engine. This invention made it easier to move goods and power machines. It helped build large cities and connect countries through trade. In 1928, Alexander Fleming discovered penicillin, the first antibiotic. This medicine saved many lives by treating infections and changed the way doctors and hospitals work all over the world.
Science also helps governments make better decisions. When leaders use evidence and facts, they can solve big problems like climate change, diseases, and food shortages. For example, the Intergovernmental Panel on Climate Change (IPCC) studies thousands of scientific papers to give advice about global warming. In 1987, the Montreal Protocol helped protect the ozone layer by banning harmful gases called CFCs. Scientists showed that CFCs were damaging the atmosphere, and the agreement helped the ozone layer begin to heal. During the COVID-19 pandemic, groups like the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) gave advice based on science. They told people how to stay safe using masks, vaccines, and social distancing. However, not everyone followed or trusted this advice equally. Science also helps countries work together. This is called science diplomacy. Projects like the International Space Station (ISS) or joint research in the Arctic bring scientists from different countries together. These efforts can build peace and cooperation between nations.
The connection between science and society goes both ways. Science changes the world, but society also shapes how science is done. People's values, culture, money, and politics all influence what research is supported and how results are used. For example, during the Cold War, the U.S. focused heavily on space research after the Soviet Union launched Sputnik 1 in 1957. This led to the creation of NASA and more investment in science and engineering education. Politics and fear of falling behind in space technology drove this big push. Social movements can also change science. In the 1970s, feminist groups pointed out that medical research mostly focused on men. Because of this, rules changed so women had to be included in clinical trials. This helped scientists understand how treatments can work differently in men and women. In farming, many people worry about genetically modified organisms (GMOs). This public concern has led to different rules in different places. For example, Europe uses the precautionary principle, which means being more careful about approving new GMO products than in countries like the U.S. Even the way scientific papers are shared is shaped by money and business models. Many journals charge people to read studies, which has caused debates about whether scientific knowledge should be free and open to everyone.
Science also helps grow economies and create new jobs. Many big industries, like biotechnology, renewable energy, artificial intelligence, and aerospace, are based on years of scientific research. For example, the semiconductor industry, which makes computer chips, came from early work in solid-state physics. Today, it is a global industry worth trillions of dollars. Governments often help science and technology grow by giving tax breaks, supporting patents, and creating partnerships between public and private groups. In countries like South Korea and Israel, spending more than 4% of the country’s income on research and development (R&D) has helped build strong technology industries. However, new technology can also cause problems. Sometimes, machines and computers take over jobs that people used to do. This is called technological unemployment. It raises hard questions about what to do when people lose their jobs because of automation. Ideas like universal basic income, job training programs, and better education are being discussed to help people adapt to these changes.
Understanding science is important for everyone. It helps people make smart choices, stay healthy, and take part in important debates. This is called scientific literacy. When people understand basic science, they can check if information is true and avoid being misled. If many people do not understand science, it can lead to misinformation. For example, some people still believe vaccines cause autism. This false idea came from a study that was later proven wrong and taken down, but the anti-vaccine movement still exists and causes real harm. Other examples include denying climate change or following pseudoscientific health ideas that are not supported by evidence. To help the public understand science better, many things are being done. Schools are improving science classes, scientists give public talks, and science journalists write easy-to-understand articles. Organizations like the American Association for the Advancement of Science (AAAS) and the British Science Association also organize science festivals and help scientists learn how to talk clearly to the public. People can also take part in citizen science. These are projects where regular people help collect data for scientific studies. Examples include watching birds through eBird or testing water through FreshWater Watch. These projects help people feel more connected to science and show that science is for everyone, not just experts.
As science becomes more powerful, it also raises ethical and philosophical questions. New technologies like gene editing, brain-computer links, and geoengineering can change human life and the planet in big ways. People must think carefully about what is right or wrong when using these tools. For example, a tool called CRISPR-Cas9 might one day cure genetic diseases. But it could also be used to create “designer babies,” which may increase unfairness in society or bring back dangerous ideas like eugenics. Artificial intelligence (AI) is another case. When AI is used to help police or choose job applicants, it can carry hidden biases from the data it was trained on. This has led to calls for fair and transparent AI systems. To deal with these big issues, there are special groups that work on science and ethics. These include The Hastings Center, the Nuffield Council on Bioethics, and UNESCO’s Bioethics Program. They help create rules and ideas that respect human rights, justice, and the limits of science. These discussions are not just for scientists. They also involve ethicists, lawyers, religious leaders, and the general public. This helps make sure that science is used in ways that are fair and good for everyone.
Many of today’s biggest problems, like diseases, climate change, and food shortages, affect the whole world. Solving them requires international cooperation and fair access to scientific knowledge. But there are still big differences between richer and poorer countries, often called the Global North and the Global South. Wealthy countries usually lead in science. They have more money for research, better equipment, and more universities. In contrast, many low- and middle-income countries struggle with problems like not enough funding, brain drain (when scientists leave to work in richer countries), and limited access to scientific tools and journals. Some groups are working to close this gap. For example, TWAS (The World Academy of Sciences) and INASP (International Network for the Availability of Scientific Publications) help support science in developing countries. They promote regional cooperation, open-access publishing, and training programs to build research skills. The idea of open science, supported by UNESCO, says that scientific knowledge should be freely available to everyone. It also encourages scientists to work together, share results, and be transparent about how they do their research. A good example of open science is what happened during the COVID-19 pandemic. Scientists around the world used platforms like GISAID to quickly share data about the virus’s genes. This helped track new versions of the virus and develop better responses faster. However, there are still challenges. Sometimes, patents and intellectual property rules make it hard for poorer countries to get important technologies, like vaccines or medical treatments. This shows that fairness in science is not just about sharing knowledge, it is also about making sure everyone can use it.
Criticisms and limitations
Science is the best tool humans have for understanding and predicting how nature works. But it is not perfect. Science has limits, and it is not always free from mistakes or bias. Science depends on observation, testing, and the idea that ideas should be falsifiable, which means they can be proven wrong if new evidence shows up. Because of this, science cannot answer questions that are metaphysical (about things beyond the physical world), emotional, or based on personal values. These kinds of questions cannot be tested or measured with tools and experiments. For example, science can study what happens in the brain during meditation, but it cannot fully explain what a person feels during that experience. This is part of a big question in philosophy and brain science called the problem of consciousness. Scientists also disagree about how best to explain complex systems. Some believe that everything can be broken down into smaller parts (reductionism), while others think that new properties appear when parts come together (emergentism). This is an important debate in areas like neuroscience and systems biology.
Some philosophers have said that science is not as objective as it may seem. For example, Thomas Kuhn argued that what scientists observe is affected by the theories they already believe. This idea is called theory-ladenness. In his famous book The Structure of Scientific Revolutions (1962), Kuhn said that science does not always move forward step by step. Instead, it goes through big changes called paradigm shifts, times when one way of thinking is replaced by another. A good example is how Einstein’s relativity replaced Newton’s mechanics. Kuhn also said that during these shifts, scientists working under different theories may not agree on what counts as proof or even what questions are important. This makes it hard to compare old and new ideas fairly. Another thinker, Paul Feyerabend, said that there is no single "scientific method" that always works. In his book Against Method (1975), he said that in the history of science, sometimes “anything goes.” He believed that too many strict rules in science can actually stop progress. One example is how Galileo’s telescope was at first seen as untrustworthy by many scientists of his time. People did not trust what it showed because it was new and did not fit their existing ideas. This shows that new tools and ideas are sometimes rejected, not because they are wrong, but because they challenge the way people already think.
One basic problem in science is called the problem of induction. It was explained by philosopher David Hume in the 1700s. The problem asks: how can we be sure that something will always happen just because it has happened many times before? For example, the sun has risen every day in history, but that does not guarantee it will rise tomorrow. Yet, science often assumes that nature follows regular patterns like this. Philosopher Karl Popper tried to solve this problem by saying that science should focus on proving ideas false, not just confirming them. This is called falsifiability. According to Popper, science moves forward by getting rid of wrong theories. But this approach also has problems. If an experiment gives unexpected results, scientists do not always throw out the theory. Sometimes they blame the tools, the way the data was read, or unknown factors. For example, if a telescope shows strange data about a planet, the issue might be with the telescope, not the theory. So it is not always clear when a theory has truly been disproven. This shows that scientific ideas are not final truths. They can change when new evidence appears or when old evidence is understood in a new way.
Social and cultural factors also affect science. They influence what gets studied, who gets to do the research, and how results are shared. Most science today is led by institutions in the Western world, and it is often written in English. This has raised concerns about epistemic colonialism, where knowledge from non-Western cultures, like Indigenous traditions or ancient medical systems, is ignored or only accepted when explained in Western scientific terms. For example, Ayurveda and Traditional Chinese medicine have been used for thousands of years. But in modern science, they are often not taken seriously unless specific parts of them are tested in lab conditions or clinical trials. There are also problems inside the scientific community. Many researchers are under pressure to publish lots of papers to keep their jobs. This is called "publish or perish." It can lead to rushed studies, weak results, and even bad practices like p-hacking (changing data to get the desired result). These issues are part of what's known as the replication crisis, when other scientists try to repeat a study but do not get the same results. One big study in 2015, called the Open Science Collaboration, tried to repeat 100 famous psychology experiments. Only 36% of them gave similar results. This showed that many scientific findings may not be as reliable as once thought.
Science works best when it is honest and independent. But sometimes, economic and political pressures can affect what scientists study, how results are shared, and whether the truth is told. For example, in the 1900s, tobacco companies paid for studies that made smoking look safer than it really was. They tried to hide the fact that smoking causes cancer. This delayed laws to protect people and led to millions of deaths. The fossil fuel industry has done something similar. By funding certain research groups and articles, they tried to make people doubt the strong scientific agreement that human actions are causing climate change. These actions are examples of corporate influence over science, which can reduce public trust and keep people from knowing the full truth. Governments can also interfere with science. During the early COVID-19 pandemic, some leaders delayed sharing important data or ignored the advice of health experts. This may have made the pandemic worse and hurt people’s trust in science and government decisions. To keep science honest, there must be transparency (open sharing of methods and results) and safeguards that protect scientists from outside pressure.
Science often uses controlled experiments to find clear answers. But some problems are too complex for this method to work perfectly. Fields like climate science, epidemiology (the study of diseases), and ecology deal with systems that have many parts working together. Because of this, scientists must use models and probabilities to make predictions. For example, climate models look at how things like greenhouse gases, ocean currents, and weather patterns interact. These models can show possible future trends, but they cannot predict exactly what will happen in a specific place at a specific time many years ahead. Sometimes people misunderstand this. They think that if science is uncertain, it must be wrong. But in complex systems, uncertainty is normal. It does not mean the science is bad. The same problem appears in nutritional science. It is hard to study diet because people eat many things at once, and other factors (like sleep or exercise) affect health too. This can lead to confusing or changing advice about what is healthy. Even in areas with experiments, like genetics, scientists have learned that things are more complicated than they once thought. Many diseases cannot be explained by a single gene. Instead, they are caused by interactions between many genes and environmental factors. This shows that reductionism, studying only small parts of a problem, can miss the bigger picture when dealing with complex systems.
Science is a powerful way to learn about the natural world, but it has limits. Some important questions cannot be answered by science alone. These include normative (what we should do), existential (why we exist), and metaphysical (beyond the physical world) questions. For example, science cannot fully answer “What is the meaning of life?”, “Is there a God?”, “What is morally right or wrong?”, or “What is consciousness?”. Science can study things we can see and test, like how the brain works. For instance, neuroscience can show how parts of the brain light up when we make choices. But it cannot tell us what we should do morally. This is known as the is–ought problem, explained by philosopher David Hume. In the same way, evolutionary biology can explain how helping others (altruism) may have developed in humans. But it cannot say whether we should be kind from a moral point of view. These types of questions are explored through philosophy, religion, ethics, and the humanities (like history and literature). Thinking that science is the only way to gain knowledge is called the scientism fallacy. It ignores the important insights from other areas of human thought, like art, culture, and spiritual traditions.
People’s trust in science is not the same everywhere. It depends on their background, politics, and past experiences. In some places, people see science as something only for experts or something that does not care about their real-life problems. This is especially true in communities that have been treated unfairly by scientific institutions in the past. One well-known case is that of Henrietta Lacks, an African-American woman whose cancer cells were taken without her permission in the 1950s. Her cells were used in many scientific breakthroughs, but her family was never asked or informed. This case is still discussed today in conversations about bioethics (the ethics of medical and scientific research) and trust in science. To build trust, it is not enough to just explain science better. Scientists also need to include different communities, listen to their concerns, and make research more open and fair. People also get confused when scientific advice changes. For example, during the COVID-19 pandemic, guidelines about wearing masks changed as scientists learned more. Some people saw this as a sign that science was unreliable. But in reality, this shows how science works, it updates when new evidence becomes available. That is a strength, not a weakness, but it must be clearly explained so the public understands why advice sometimes changes.


Genetics: Genetics is a discipline of biology. It is the science of heredity. This includes the study of genes, and the inheritance of variation and traits of living organisms. In the laboratory, genetics works by mating carefully selected organisms, and analysing their offspring. More informally, genetics is the study of how parents pass some of their characteristics to their children. It is an important part of biology, and gives the basic rules on which evolution acts.
The fact that living things inherit traits from their parents has been known since prehistoric times. It is used to improve crop plants and animals by selective breeding. The modern science of genetics tries to understand the process of inheritance. This began with the work of Gregor Mendel in the mid-nineteenth century. Although he did not know the physical basis for heredity, Mendel saw that organisms inherit traits via discrete units of inheritance, now called genes.
Modern genetics has expanded beyond inheritance. It studies the way genes work.
 DNA 
Living things are made of millions of tiny self-contained components called cells. Inside each cell are long and complex molecules called deoxyribonucleic acid, known for short as DNA. Some DNA stores information for making proteins. The bits of DNA which do this are known as genes. People look different from each other mainly because they have different versions of the human set of genes. 
However, a large part of DNA (more than 98% for humans) is non-coding DNA. These sections do not serve as patterns for protein sequences. What it does is code for important non-protein information. Examples are various important RNA molecules, and "scaffolding" bits and pieces like centromeres and telomeres. 
Every cell in the same living thing has the same DNA, but only some of it is used in each cell. For instance, some genes that tell how to make parts of the liver are switched off in the brain. What genes are used can also change over time. For instance, a lot of genes are used by a child early in pregnancy that are not used later.
A person has two copies of each gene, one from their mother, and one from their father. There can be several types of a single gene, which give different instructions: one version might cause a person to have blue eyes, another might cause them to have brown. These different versions are known as alleles of the gene.
Since a living thing has two copies of each gene, it can have two different alleles of it at the same time. Often, one allele will be dominant, meaning that the living thing looks and acts as if it had only that one allele. The unexpressed allele is called recessive. In other cases, you end up with something in between the two possibilities. Both alleles are expressed.
Most of the characteristics that you can see in a living thing have more than one gene which influences them. And many genes have multiple effects on the body, because their function will not have the same effect in each tissue. The multiple effects of a single gene is called pleiotropism. The whole set of genes is called the genotype, and the total effect of genes on the body is called the phenotype. These are key terms in genetics.
 History of genetics 
 Pre-Mendelian ideas 
We know that man started breeding domestic animals from early times, probably before the invention of agriculture. We do not know when heredity was first appreciated as a scientific problem. The Greeks, and most obviously Aristotle, studied living things, and proposed ideas about reproduction and heredity.
Imre Festetics, who published work in German in the first part of the 19th century, was totally forgotten until recently. He described several rules of genetic inheritance in his work Die genetische Gesätze der Natur, 1819 (The genetic law of nature). His second law is the same as Mendel. In his third law, he developed the basic principles of mutation. None of the histories of genetics published in the 20th century mentions him.
Probably the most publicized idea before Mendel was that of Charles Darwin, whose idea of pangenesis had two parts. The first, that persistent hereditary units were passed on from one generation to another, was quite right. The second was his idea that they were replenished by 'gemmules' from the somatic (body) tissues. This was entirely wrong, and plays no part in science today. Darwin was right about one thing: whatever happens in evolution must happen by means of heredity, and so an accurate science of genetics is fundamental to the theory of evolution. This 'mating' between genetics and evolution took many years to organise. It resulted in the modern evolutionary synthesis.
 Mendelian genetics 
The basic rules of genetics were discovered by Imre Festetics, a landowner (17641847), and a monk named Gregor Mendel around 1865. For thousands of years people had noticed how some traits in parents are passed to their children. However, Mendel's work was different because he designed his experiments very carefully.
In his experiments, Mendel studied how traits were passed on in pea plants. He started his crosses with plants that bred true, and counted characters that were either/or in nature (either tall or short). He bred large numbers of plants, and expressed his results numerically. He used test crosses to reveal the presence and proportion of recessive characters.
Mendel explained the results of his experiment using two scientific laws:
 1. Factors, later called genes, normally occur in pairs in ordinary body cells, yet separate during the formation of sex cells. These factors determine the organism's traits, and are inherited from its parents. When gametes are produced by meiosis, the two factors separate. A gamete only receives one or the other. This Mendel called the Law of segregation.
 2. Alleles of different genes separate independently of one another when gametes are formed. This he called the Law of Independent Assortment. So Mendel thought that different traits are inherited independently of one another. We now know this is only true if the genes are not on the same chromosome, in which case they are not linked to each other.
Mendel's laws helped explain the results he observed in his pea plants. Later, geneticists discovered that his laws were also true for other living things, even humans. Mendel's findings from his work on the garden pea plants helped to establish the field of genetics. His contributions were not limited to the basic rules that he discovered. Mendel's care towards controlling experiment conditions along with his attention to his numerical results set a standard for future experiments. Over the years, scientists have changed and improved Mendel's ideas. However, the science of genetics would not be possible today without the early work of Gregor Mendel.
 Between Mendel and modern genetics 
Between Mendel's work and 1900 the foundations of cytology, the study of cells, was developed. The facts discovered about the nucleus and cell division were essential for Mendel's work to be properly understood.
1832: Barthélémy Dumortier, the first to observe cell division in a multicellular organism.
1841, 1852: Robert Remak (1815–1865), a Jewish Polish–German physiologist, was the first person to state the foundation of cell biology: that cells only derive from other cells. This was later popularized by the German doctor Rudolf Virchow (1821–1902), who used the famous phrase omnis cellula e cellula, meaning, all cells from other cells.
1865: Gregor Mendel's paper, Experiments on plant hybridization was published.
1876: Meiosis was discovered and described for the first time in sea urchin eggs, by German biologist Oscar Hertwig (1849–1922).
1878–1888: Walther Flemming and Eduard Strasburger describe chromosome behaviour during mitosis.
1883: Meiosis was described at the level of chromosomes, by Belgian zoologist Edouard van Beneden (1846–1910), in Ascaris (roundworm) eggs.
1883: German zoologist Wilhelm Roux (1850–1924) realised the significance of the linear structure of chromosomes. Their splitting into two equal longitudinal halves meant each daughter cell got the same chromosome complement. Therefore, chromosomes were the bearers of heredity.
1889: Dutch botanist Hugo de Vries suggests that "inheritance of specific traits in organisms comes in particles", naming such particles (pan)genes.
1890: The significance of meiosis for reproduction and inheritance was described in 1890 by German biologist August Weismann (1834–1914). He noted that two cell divisions were necessary to turn one diploid cell into four haploid cells if the number of chromosomes was to be maintained.
1902–1904: Theodor Boveri (1862–1915), a German biologist, in a series of papers, drew attention to the correspondence between the behaviour of chromosomes and the results obtained by Mendel. He said that chromosomes were "independent entities which keep their independence even in the resting nucleus... What comes out of the nucleus is what goes into it".
1903: Walter Sutton suggested that chromosomes, which segregate in a Mendelian fashion, are hereditary units. Edmund B. Wilson (1856–1939), Sutton's teacher, was the author of one of the most famous text-books in biology. Wilson called this idea the Sutton–Boveri hypothesis.
At this point, discoveries in cytology merged with the rediscovered ideas of Mendel to make a fusion called cytogenetics, (cyto = cell; genetics = heredity) which has continued to the present day.
 Rediscovery of Mendel's work 
During the 1890s several biologists began doing experiments on breeding. and soon Mendel's results were duplicated, even before his papers were read. Carl Correns and Hugo de Vries were the main rediscoverers of Mendel's writings and laws. Both acknowledged Mendel's priority, although it is probable that de Vries did not understand his own results until after reading Mendel. Though Erich von Tschermak was originally also credited with rediscovery, this is no longer accepted because he did not understand Mendel's laws. Though de Vries later lost interest in Mendelism, other biologists built genetics into a science.
Mendel's results were replicated, and genetic linkage soon worked out. William Bateson perhaps did the most in the early days to publicise Mendel's theory. The word genetics, and other terminology, originated with Bateson.
Mendel's experimental results were later the object of some debate. Fisher analysed the results of the F2 (second filial) ratio and found them to be implausibly close to the exact ratio of 3 to 1. It is sometimes suggested that Mendel may have censored his results, and that his seven traits each occur on a separate chromosome pair, an extremely unlikely occurrence if they were chosen at random. In fact, the genes Mendel studied occurred in only four linkage groups, and only one gene pair (out of 21 possible) is close enough to show deviation from independent assortment; this is not a pair that Mendel studied.
 Tools of genetics 
 Mutations 
During the process of DNA replication, errors sometimes occur. These errors, called mutations, can have an effect on the phenotype of an organism. In turn, that usually has an effect on the organism's fitness, its ability to live and reproduce successfully.
Error rates are usually very low—1 error in every 10–100 million bases—due to the "proofreading" ability of DNA polymerases. Error rates are a thousandfold higher in many viruses. Because they rely on DNA and RNA polymerases which lack proofreading ability, they get higher mutation rates.
Processes that increase the rate of changes in DNA are called mutagenic. Mutagenic chemicals increase errors in DNA replication, often by interfering with the structure of base-pairing, while UV radiation induces mutations by causing damage to the DNA structure. Chemical damage to DNA occurs naturally as well, and cells use DNA repair mechanisms to repair mismatches and breaks in DNA—nevertheless, the repair sometimes fails to return the DNA to its original sequence.
In organisms which use chromosomal crossovers to exchange DNA and recombine genes, errors in alignment during meiosis can also cause mutations. Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt a mistaken alignment; this makes some regions in genomes more prone to mutating in this way. These errors create large structural changes in DNA sequence—duplications, inversions or deletions of entire regions, or the accidental exchanging of whole parts between different chromosomes (called translocation).
 Punnett squares 
Developed by Reginald Punnett, Punnett squares are used by biologists to determine the probability of offspring having a particular genotype.
If B represents the allele for having black hair and b represents the allele for having white hair, the offspring of two Bb parents would have a 25% probability of having two white hair alleles (bb), 50% of having one of each (Bb), and 25% of having only black hair alleles (BB).
 Pedigree chart 
Geneticists (biologists who study genetics) use pedigree charts to record traits of people in a family. Using these charts, geneticists can study how a trait is inherited from person to person.
Geneticists can also use pedigree charts to predict how traits will be passed to future children in a family. For instance, genetic counselors are professionals who work with families who might be affected by genetic diseases. As part of their job, they create pedigree charts for the family, which can be used to study how the disease might be inherited.
 Twin studies 
Since human beings are not bred experimentally, human genetics must be studied by other means. One recent way is by studying the human genome. Another way, older by many years, is to study twins.
Identical twins are natural clones. They carry the same genes, they may be used to investigate how much heredity contributes to individual people. Studies with twins have been quite interesting. If we make a list of characteristic traits, we find that they vary in how much they owe to heredity. For example:
Eye colour: entirely inherited
Weight, height: partly inherited, partly environmental
Which language a person speaks: entirely environmental.
The way the studies are done is like this. Take a group of identical twins and a group of fraternal twins. Measure them for various traits. Do a statistical analysis (such as analysis of variance). This tells you to what extent the trait is inherited. Those traits which are partly inherited will be significantly more similar in identical twins. Studies like this may be carried further, by comparing identical twins brought up together with identical twins brought up in different circumstances. That gives a handle on how much circumstances can alter the outcomes of genetically identical people.
The person who first did twin studies was Francis Galton, Darwin's half-cousin, who was a founder of statistics. His method was to trace twins through their life-history, making many kinds of measurement. Unfortunately, though he knew about mono and dizygotic twins, he did not appreciate the real genetic difference. Twin studies of the modern kind did not appear until the 1920s.
 Genetics of prokaryotes and viruses 
The genetics of bacteria, archaea and viruses is a major field of research. Bacteria mostly divide by asexual cell division, but do have a kind of sex by horizontal gene transfer. Bacterial conjugation, transduction and transformation are their methods. In addition, the complete DNA sequence of many bacteria, archaea and viruses is now known.
Although many bacteria were given generic and specific names, like Staphylococcus aureus, the whole idea of a species is rather meaningless for an organism which does not have sexes and crossing-over of chromosomes. Instead, these organisms have strains, and that is how they are identified in the laboratory.
 Genes and development 
 Gene expression 
Gene expression is how the heritable information in a gene, the sequence of DNA base pairs, is made into a functional gene product, such as protein or RNA. The basic idea is that DNA is transcribed into RNA, which is then translated into proteins. Proteins make many of the structures and all the enzymes in a cell or organism.
Several steps in the gene expression process may be modulated (tuned). This includes both the transcription and translation stages, and the final folded state of a protein. Gene regulation switches genes on and off, and so controls cell differentiation, and morphogenesis. Gene regulation may also serve as a basis for evolutionary change: control of the timing, location, and amount of gene expression can have a profound effect on the development of the organism. The expression of a gene may vary a lot in different tissues. This is called pleiotropism, a widespread phenomenon in genetics.
Alternative splicing is a modern discovery of great importance. It is a process where from a single gene a large number of variant proteins can be assembled. One particular Drosophila gene (DSCAM) can be alternatively spliced into 38,000 different mRNA molecules.
 Epigenetics & control of development 
Epigenetics is the study of changes in gene activity which are not caused by changes in the DNA sequence. It is the study of gene expression, the way genes bring about their phenotypic effects.
These changes in gene activity may stay for the remainder of the cell's life and may also last for many generations of cells, through cell divisions. However, there is no change in the underlying DNA sequence of the organism. Instead, non-hereditary factors cause the organism's genes to behave (express themselves) differently.
Hox genes are a complex of genes whose proteins bind to the regulatory regions of target genes. The target genes then activate or repress cell processes to direct the final development of the organism.
 Extranuclear inheritance 
There are some kinds of heredity which happen outside the cell nucleus. Normal inheritance is from both parents via the chromosomes in the nucleus of a fertilised egg cell. There are some kinds of inheritance other than this.
 Organelle heredity 
Mitochondria and chloroplasts carry some DNA of their own. Their make-up is decided by genes in the chromosomes and genes in the organelle. Carl Correns discovered an example in 1908. The four o'clock plant, Mirabilis jalapa, has leaves which may be white, green or variegated. Correns discovered the pollen had no influence on this inheritance. The colour is decided by genes in the chloroplasts.
 Infectious heredity 
This is caused by a symbiotic or parasitic relationship with a microorganism.
 Maternal effect 
In this case nuclear genes in the female gamete are transcribed. The products accumulate in the egg cytoplasm, and have an effect on the early development of the fertilised egg. The coiling of a snail, Limnaea peregra, is determined like this. Right-handed shells are genotypes Dd or dd, while left-handed shells are dd.
The most important example of maternal effect is in Drosophila melanogaster. The protein product maternal-effect genes activate other genes, which in turn activate still more genes. This work won the Nobel Prize in Physiology or Medicine for 1995.
 Aspects of modern genetics 
Much modern research uses a mixture of genetics, cell biology and molecular biology. Topics which have been the subject of Nobel Prizes in either chemistry or physiology include:
Alternative splicing, where one gene codes for a variety of related protein products.
Genomics, the sequence and analysis the function and structure of genomes. 
Genetic engineering, the changing of an organism's genome using biotechnology.
Mobile genetic elements, types of DNA which can change position in the genome.
Horizontal gene transfer, where an organism gets genetic material from another organism without being the offspring of that organism.
Epigenetics, the study of changes in gene activity which are not caused by changes in the DNA sequence.
CRISPR: In 2012, Jennifer Doudna and Emmanuelle Charpentier suggested that CRISPR-Cas9 (enzymes from bacteria which control microbial immunity) could be used to edit genomes. This has been called one of the most significant discoveries in the history of biology. The two scientists shared the 2020 Nobel Prize in Chemistry.
 Genetics of human behaviour 
Many well-known disorders of human behaviour have a genetic component. This means that their inheritance partly causes the behaviour, or makes it more likely the problem would occur. Examples include:
Autism
ADHD (attention deficit disorder)
Drug use and abuse
Risk taking
Schizophrenia
Also, normal behaviour is also heavily influenced by heredity:
Learning and cognitive ability
Personality.


Human rights: Human rights are rights and freedoms that all people should have. 
Today, the ideas of human rights are protected as legal rights in national and international law.
They are seen as universal, which means they are meant for everyone, no matter what their race, religion, ethnicity, nationality, age, sex, political beliefs (or any other kind of beliefs), intelligence, disability, sexual orientation, or gender identity are.
Every person has all of these rights, it is not possible to only grant some of them:
 History 
The idea of human rights originated from ideas found in religion and philosophy in Western Europe. The modern Western idea of human rights started in the European Enlightenment. In the 16th century, some people started suggesting that everyone had the religious and political right to choose their religion and their leaders. This sort of thinking was important in the English Civil War. After the war, the philosopher John Locke argued that people should have a certain set of human rights. These ideas were also important in the American revolution and the French revolution in the 18th century.
In the 19th century, John Stuart Mill was an important philosopher who also thought about human rights. He said that people should be able to control their own bodies and minds. He talked about three special ideas:
 freedom of speech
 freedom of assembly
 freedom to seek happiness, while not hurting others.
Hegel was a philosopher who wrote about the idea of free will. He believed that in order to have freedom, a person should be able to: 
 own property
 make contracts with other people
 make moral promises to people
 live with anyone
 get protection from laws
 have a voice in government
 Laws 
Because people believe that human rights are important, countries make laws to protect them. These laws say that governments cannot take away people's basic rights. They make sure people who take away other people's rights are punished. However, many countries in the world do not protect the human rights of their people.
Some major political groups and countries have made statements that promote human rights. Many governments and international groups punish human rights violators by refusing to trade with them, or even helping groups that want to overthrow their governments.
Some of the important places that human rights laws are written is in constitutions. The United States Constitution and Constitution of France are two of the oldest set of laws based on human rights.
In 1948 the United Nations made the Universal Declaration of Human Rights. This is a widely respected document that lists what the United Nations believes are human rights. It is not a law, but two important agreements have been written based on its ideas:
 The International Covenant on Civil and Political Rights
 The International Covenant on Economic, Social and Cultural Rights
These are United Nations human rights Covenants: agreements between people or countries. The countries who sign these two covenants agree to follow them.
In addition to those Declaration and Covenants, there are many treaties and documents made by United Nations and other international organizations. Those treaties and documents are called "International human rights law".
 List of human rights 
Not everyone agrees on what the basic human rights are. It is clear that few countries permit all these rights. Also, there are countries in which the rights are not illegal, but nothing is done to promote them. Here is a list of some of the most recognized rights:
 Fundamental rights 
See the article Fundamental rights
 Right to live
 To be a citizen of a country
 Right to housing
 Right to a fair trial
 To own property
 Safety 
 Safety from violence (physical, mental and sexual)
 To seek asylum if a country treats you badly
 Fair trial, and to be considered innocent until proven guilty
 Especially in America, owning weapons like guns to protect yourself
 General life freedoms 
 The right to get an education
 Health care (medical care) 
 To believe and practice the religion a person wants
 To be protected one's privacy
 Rights related to sexuality and procreation 
 Right to marriage and family
 Equality of both males and females; women's rights
 Not be forced into marriage
 The right to express orientation
 Political freedoms 
 The right to express yourself: free speech
 To vote
 To peacefully protest (speak against) a government or group
 To petition
 Abuses 
Human rights abuses are when a person is hurt in a way that violates (goes against) his/her human rights. Human rights abuses are also often called human rights violations.
Examples of human rights abuses or violations are:
 Arresting someone because they said the government is doing bad things
 Not letting people practice their religion
 Genocide 
 Not letting a member of a country vote.
Many people, groups, and countries think protecting human rights is very important. But not everyone in the world believes in human rights. If people who do not believe in human rights have political power they can hurt many people. Even if these people have no political power, they can be violent to other people. There are many people who work to protect everyone's human rights; some of these are government groups, and some are not with any government. They are sometimes called human rights organizations. Amnesty International and Human Rights Watch are examples of human rights organizations.
In the UK, every Act of Parliament must comply with the European Convention on Human Rights. Nonetheless, a person can challenge an Act if it violates the convention. However, the Government are not bound to change the law due to incompatibility, and they have the power to pass a law that contravenes with the Human Rights, if they wish.


History of India: December 2023
The History of India covers thousands of years and discusses many diverse languages, cultures, periods, and dynasties. Indian civilization began in the Indus Valley and some literature survives from that time. 
 Stone age 
 Paleolithic era 
Remains (stone tools and a skull) in central India show presence of an early species of humans, Homo erectus. Archeologists think they lived in India between 200,000 and 500,000 years ago. This period is known as the paleolithic era.
The earliest archaeological site in the subcontinent is the paleolithic hominid site in the Soan River valley. Soanian sites are found in the Sivalik region across India, Pakistan and Nepal.
 Mesolithic 
Modern humans (Homo sapiens) settled in the Indian subcontinent at least 70,000 years ago. At that time, the last ice age had just ended and the climate became warm and dry. The first settlements are found in Bhimbetka, near Bhopal (Madhya Pradesh, India). Mesolithic people lived by hunting, fishing and food gathering.
 Neolithic 
Neolithic agriculture started in the Indus Valley region around 7000 years ago, in the lower Gangetic valley around 5000 years ago. Later, in South India, agriculture spread southwards and also into Malwa around 3800 years ago.
 Bronze Age 
The Bronze Age in the Indian subcontinent began around 5300 years ago with the early Indus Valley Civilisation, which included cities such as Harappa, Mohenjodaro, Lothal, and Kalibanga. The civilization was based on the Indus River and its tributaries, extending into the Ghaggar-Hakra River valley, the Ganges-Yamuna Doab, Gujarat, and southeastern Afghanistan. Today, the civilization's old territory is split between India and Pakistan. In Pakistan, the provinces of Sindh, Punjab, and Balochistan overlap with ex-Indus Valley territory. In India, the provinces Gujarat, Haryana, Punjab and Rajasthan also share territory with the Indus Valley Civilization.
The first cities on the Indian subcontinent were part of the Indus Valley Civilisation. They were similar to early Mesopotamian civilisations and Ancient Egypt. Inhabitants of the ancient Indus river valley, the Harappans, developed new techniques in metallurgy and handicraft (carneol products, seal carving), and produced copper, bronze, lead, and tin.
The mature Indus civilization flourished from about 4600 to 3900 years ago. It included urban centers such as Dholavira, Kalibanga, Ropar, Rakhigarhi, and Lothal in modern-day India, and Harappa, Ganeriwala, and Mohenjo-daro in modern-day Pakistan. The cities were built of brick, with roadside drainage system and multi-storied houses. During the later period of this civilisation, signs of a gradual decline began to emerge. By about 3700 years ago, most of the cities were abandoned. However, the Indus Valley Civilisation did not disappear suddenly. Some parts of the Indus Civilization may have survived in the smaller villages and isolated farms.
 Vedic civilization 
The Vedas are the oldest teachings of India, though the transmission of these teachings was mainly oral until around the 5th century. There are four Vedas, and the oldest is the Rigveda. As per Rigveda the whole region is SaptaSindhawa, the land of seven rivers. The other three are Samaveda, Yajurveda and Atharvaveda. The Vedas have verses in praise of gods and others. They also have other information. At that time, the society was pastoral.
After the Rigveda, society became more agricultural. People became divided into four classes depending on the type of the work. Brahmins were priests and teachers. Kshatriyas were the warriors. Vaishyas did agriculture, trading and commerce. The shudras were the general working class. It is not true that the Vaishyas and Shudras were always looked down upon, and treated badly by Brahmins and Kshatriyas, though it was true for the later part of the Vedic age. But it was untrue for the earlier part. This type of social division is called the Varna system in Hinduism.
During the period of the Later Vedic civilization, there were many Aryan clans and tribes. Some of them combined and became bigger like the kingdom of the Kurus.
 Persian and Greek invasion 
The names "India" and "Hind" came from the Greeks and Persians. It means land of the river Indus in both languages.
Around the 5th century BC, north-western parts of India were invaded by the Achaemenid Empire and by the Greeks of Alexander the Great. A Persian way of thinking, administration and lifestyle came to India. This influence became bigger during the Mauryan dynasty. From around 520 BC, the Achaemenid Empire’s Darius I ruled large part of northwestern parts of the Indian subcontinent. Alexander later conquered these areas. Achaemenid rule lasted about 186 years. In modern times, there are still traces of this Greek heritage to be found in parts of northwestern India. Greco-Buddhism is a combination of the cultures of Greece and Buddhism. This mixture of cultures developed for 800 years, from the 4th century BC until the 5th century AD. The area where it happened is modern day’s Afghanistan and Pakistan. This mixture of cultures influenced Mahayana Buddhism and the spread of Buddhism to China, Korea, Japan and Tibet.
 The Mauryan empire 
The Magadha was one of the sixteen kingdoms in ancient India. The core of the kingdom was the area of Bihar south of the Ganges. Its first capital was Rajagriha (modern Rajgir) then Pataliputra (modern Patna). Magadha expanded to include most of Bihar and Bengal, followed by much of eastern Uttar Pradesh and Odisha. The ancient kingdom of Magadha is mentioned in Jain and Buddhist texts. It was also mentioned in the Indian epics Ramayana and Mahabharata.June 2023 The state of Magadha was a historical Iron age kingdom and is recorded in Vedic texts much earlier than 600 BC. Magadha played an important role in the development of Jainism and Buddhism, and two of India's greatest empires, the Maurya Empire and Gupta Empire, originated from Magadha. The Mauryan empire under Ashoka was a highly centralized state and managed to unite most of the Indian subcontinent for the first time. Ashoka also helped to spread Buddhism. The Gupta empire saw advances in science, mathematics, astronomy, religion, and philosophy and is traditionally considered India's Golden age.
 Early middle kingdoms 
 Satavahana empire 
The Satavahanas came to power from around 230 BC. They are also called Andhras. For about 450 years, Satavahanas kings ruled most parts of the southern and central India.
 Western Kshatrapas 
For about 350 years, from the years 35-405, Saka kings ruled the western and central parts of India. These areas are in today's states of Gujarat, Maharashtra, Rajasthan, and Madhya Pradesh. There were 27 independent rulers, collectively known as the Kshatrapas.
Saka kings ruled India along aside the Kushan kings and the Satvahana kings. Kushan kings ruled the northern parts of India. Satvahana kings ruled the central and some of the southern parts of India.
 Indo-Scythians 
Indo-Scythians came to India from Siberia passing through Bactria, Sogdiana, Kashmir and Arachosia. Their coming to India continued from the 2nd century BC to the 1st century BC. They defeated the Indo-Greek rulers of India, and ruled India from Gandhara to Mathura.
 Gupta dynasty 
The Gupta dynasty reigned from around 320 to 550 AD. The Gupta Empire covered most of North-central India, and what is now western India and Bangladesh. Gupta society was ordered in accordance with Hindu beliefs. The Gupta empire saw advances in science, mathematics, astronomy, religion, and philosophy and is traditionally considered India's Golden age. Historians place the Gupta dynasty alongside the Han Dynasty, Tang Dynasty and Roman Empire as a model of a classical civilization.
 Hun invasion 
By the first half of the fifth century, a group of people known as Huns had settled in Afghanistan. They became powerful. They made Bamiyan their capital city. They started attacking northwestern parts of India. Skandagupta, an emperor of the Gupta dynasty fought back and kept them away for some years. At last the Huns won and could enter most parts of northern India. With this the Gupta dynasty came to an end. Most of north India became badly affected by this invasion. However, Huns could not go up to the Deccan Plateau and the southern parts of India. These parts remained peaceful. No one knows definitely about the fate of Huns after the end of the sixth century. Some historians believe that they mixed up fully with the Indian people of that time.
 Late Middle Kingdoms 
In the history of India the Middle kingdoms of India cover a period beginning from around the 6th-7th century. In South India, Chola kings ruled Tamil Nadu, and Chera kings ruled Kerala. They also had trading relationships with the Roman Empire to the west and Southeast Asia to the east. In north India, Rajputs ruled in many kingdoms. Some of those kingdoms continued for hundreds of years.
 Harsha's empire 
After the collapse of the Gupta Empire, it was Harsha of Kanauj (a place now in Uttar Pradesh) who united the northern parts of India in one kingdom. After his death several dynasties tried to control north India and ruled from 7th century till the 9th century as described below. Some of these dynasties were the Pratiharas of Malwa and later Kannauj; the Palas of Bengal, and the Rashtrakutas of the Deccan.
 The Pratiharas, Palas, and Rashtrakutas 
The Pratihara kings ruled kingdoms in Rajasthan and some other parts of northern India from the 6th century to the 11th century. The Palas ruled the eastern part of India. They ruled over areas which are now parts of the Indian states of Bihar, Jharkhand, west Bengal, and Bangladesh. The Palas ruled from 8th century to the 12th century. In the southern parts of India, Rashtrakutas of Malakheda (Karnataka) ruled the Deccan during the 8th-10th centuries after the end of Chalukya rule. All these three dynasties tried to control the entire north India. During this time lasting for three to four hundred years, the Chola kings were growing in power and influence.
 The Rajputs 
In the 6th century several Rajput kingdoms came into being in Rajasthan. Many other Rajput kings ruled in different parts of north India. Some of these kingdoms survived for hundreds of years.
 Vijayanagar empire 
In 1336, two brothers named Harihara and Bukka founded the Vijayanagara Empire in an area which is now in Karnataka. The most famous king of this empire was Krishnadevaraya. In 1565, rulers of this empire were defeated in a battle. But, the empire continued for about the next hundred years.
A number of kingdoms of south India had trading relations with the Arabs in the west, and with Indonesia and other countries of the east.
 Islamic sultanates 
Islam spread across the Indian subcontinent over a period of 500 years. In the 10th and 11th centuries, Turks invaded India and established sultanates in Delhi. In the early 16th century, descendants of Genghis Khan swept across the Khyber Pass and established the Mughal Empire, which lasted for 200 years. From the 11th to the 15th centuries, southern India was dominated by Hindu Chola and Vijayanagar Dynasties. During this time, the two systems—the prevailing Hindu and Muslim—mingled, left lasting cultural influences on each other.
 Delhi sultanate 
The Delhi sultanate was a Muslim kingdom based mostly in Delhi. It ruled large parts of the Indian subcontinent for 320 years (1206–1526) Five dynasties ruled over Delhi Sultanate. They are the mamaluk, khilji, tughlaq, sayyid and the lodi dynasties. The mamluk dynasty was started by Qutbuddin Aibak. He was a slave and thus this dynasty is also called Slave Dynasty. Qutubuddin Aibak also made Qutub minar. His son in law, Iltutmish became the ruler after Qutubuddin aibak. He completed the qutub minar.
 The Kingdom of Mysore 
The Kingdom of Mysore was a kingdom of southern India. People known as Wodeyars founded this kingdom in the year 1400. Later on, Hyder Ali and his son, Tipu Sultan, fought with the Wodeyar rulers. They also fought with the forces of the British Raj, but were defeated. Under the British Raj, Wodeyar kings continued to rule a large part of Karnataka. When India became independent on 15th August 1947, Wodeyars’ kingdom chose to become a part of India.
 The Punjab 
Guru Nanak founded Sikhism and his followers were called Sikhs. The power of Sikhs increased in the northwestern part of India. The Sikhs became rulers of large part of the northwestern India. This is called the Sikh Kingdom or Empire. Ranjit Singh was the most famous ruler of the Sikh Empire. He expanded the borders of the Sikh Empire and at the time of his death, it covered areas of Punjab, and present day Kashmir and parts of Pakistan. The Sikhs and forces of the British Raj fought many wars. While Maharaja Ranjit Singh was alive, Britishers were not able to cross the Sutlej river. After his death, they took over the entire Punjab after battles with disorganised Sikh troops.
 Durrani Empire 
For a short period, Ahmed Shah Durrani the founder of Afghanistan ruled some parts of northwestern India. Historians have named his rule the Durrani Empire. In 1748, he crossed the Indus River and attacked Lahore, now a part of Pakistan. He also attacked many parts of Punjab. Then, he attacked Delhi. At that time, Delhi was the capital of the Mughal Empire. He took many valuable things from India. This included the Peacock Throne of Shah Jahan and the famous diamond named Kohinoor.
 Colonial era 
Colonial period means the time when Western countries ruled India. Western countries also ruled many other countries of Asia, Africa, and South America.
 Company Rule 
Starting in the 1600s the British East India Company began a very profitable trading empire in India, centered in Bengal. In the mid-1700s Robert Clive (1725-1774) led the company to an expanded influence in India with victories over the French, the Bengalis, and the Mughals. With a victory at the Battle of Plassey in 1757 Clive became the first British Governor of Bengal.
In the hundred years after the battle, the East India Company conquered the entire subcontinent of India. They did this by trade, political intrigue, and direct military action. The British were very efficient administrators of their domains. But in 1857 the Indian Mutiny almost destroyed the company's rule of India. Afterward the British government took control away from the company. In 1858, India became a part of the British Empire and Queen Victoria became the empress of India.
 The British Raj 
For the next 100 years the British ruled most of India and Burma as an informal empire. It was divided into eight provinces each with a governor. These provinces were Burma, Bengal, Madras, Bombay, Uttar Pradesh, Central Provinces, Punjab, and Assam. A Governor-General (Viceroy) in Calcutta was head of the government.
It should be noted that the British did not control all of modern day India and neither was it all under direct British rule. A large part of the British Raj was made up of vassal Princely states who were governed by local rulers. 
Goa was under Portuguese rule and the 4 cities that comprise modern day Pondicherry were under French revolutionary sovereignty. 
British Colonial exploitation resulted in the deaths of millions of Indians due to starvation and famine. The British also introduced railways and banned Widow burning. 
There was a major rebellion against British rule in 1857. 
 Independence 
Many people in India wanted to be free from British rule. The struggle for freedom was long and difficult. Many people protested against the injustices of British rule. The most important leader of the independence movement was Mohandas K. Gandhi. Gandhi believed in a non-violent opposition towards the British. Muhammad Ali Jinnah wanted a separate state for Muslims living in the Indian subcontinent and as a result British India was partitioned in to two countries: Pakistan and India. The partition resulted in communal violence that led to the deaths of many people. India won its independence on August 15, 1947. Pakistan won independence on 14 August, a day before India. 
 Republic of India 
On 26 January 1950, India adopted a constitution. From that day, India become a republic. 
During last 60 years, the Republic of India has seen different stages in its national life. 
 It fought three wars against Pakistan, and one war against China. Wars with Pakistan were fought in 1947, 1965, and 1971. The relationship between India and Pakistan was horrendous, and will be for a long time. In 1999, it had a limited skirmish in Kargil. The war with China was fought in 1962. In 1971, the Republic of India also helped Bangladesh in its freedom struggle.
 Under the leadership of Jawaharlal Nehru (the first Prime Minister of India), India had adopted a socialist economy. Some economists think it was a mixed economy. In a mixed economy, socialism and capitalism continue together. During this period, lasting for several years up to end-1980s, India could rapidly develop its infrastructure, science and technology.
 By the early 1990s, India had changed its economic policies. It started several reforms to attract more capital from other countries. Local businessmen and industrialists also got more freedom to carry out their activities.
 In 1974, India had already detonated its first nuclear bomb. It repeated the same in 1998. With this, it became a nuclear power.
In 2018 India was the fifth largest economy in terms of gross GDP. It was the 4th largest economy of the world when accounting for purchasing power parity. Some economists think that in coming decades, India’s economy will become still larger.


Meitei people in the United States: Meitei
Meitei people (Mtei ꯃꯩꯇꯩ ꯃꯤꯌꯥꯝ), also known as the Manipuris (Mtei ꯃꯅꯤꯄꯨꯔꯤ ꯀꯥꯡꯂꯨꯞ), originally from northeastern India (mostly from Manipur) and parts of Bangladesh with Meitei populations, are a small but emerging community in the United States. As part of the broader South Asian diaspora, the Meiteis have gradually settled in various parts of the country, often driven by opportunities for education, work, and a better quality of life. While the community is still relatively small, they have begun to establish themselves within the multicultural fabric of American society. Through their migration, the Meitei people maintain a sense of connection to their cultural traditions, while also adapting to their new environment, contributing to the diverse and dynamic nature of life in the United States.
 Migration 
Manipuri migration from India to the United States began in the late 1960s. This migration primarily involved students and skilled professionals and is categorized as part of the "new diaspora." Over time, the Manipuri diaspora established communities in several states, including New Jersey, Illinois, Texas, Pennsylvania (Philadelphia), North Carolina, Washington, D.C., and California.
 Waves of Migration 
The migration occurred in successive phases:
 First Wave (1960s–1970s): This phase consisted of a small number of students and professionals who moved to the United States for education and employment. Some returned to Manipur after completing their studies.
 Second Wave (1980s–1990s): During this period, additional migrants from Manipur arrived in the United States. Their migration paralleled the broader movement of Indian professionals, particularly in information technology, who entered the United States on temporary work visas such as the H-1B. Migrants from Manipur during this wave included engineers, doctors, scientists, nurses, educators, theologians, entrepreneurs, and students.
 Third Wave (2000s-2020s): The third wave of migration from Manipur to the United States began in the early 2000s, with the Manipuri population increasing to over 100 individuals. By 2016, the population had grown to approximately 300, and by 2020, it reached around 1,000.
 Geographical distribution 
The Meitei people, also known as the Manipuris, live in different places of USA, including Virginia, Maryland, North Carolina, Texas, New Jersey, Massachusetts, Connecticut, Ohio, Indiana, Illinois, Michigan, Missouri, Tennessee, Alabama, and Florida.
 Cuisines 
Meitei cuisines in the United States refer to ethnic food and beverages prepared by members of the Meitei diaspora. Commonly included dishes are Ooti, Eromba (Mtei ꯏꯔꯣꯝꯕ), Hawaichar, Nga-thongba, traditional cheese, and Hawai. These cuisines are typically maintained within domestic spaces and community gatherings, reflecting the culinary practices of the Meitei community.
Soibum (bamboo shoots), ngari (fermented fish) and hawaizar (fermented soya beans), are also notably used.
 Dance and music 
A Manipuri dance (Mtei ꯃꯅꯤꯄꯨꯔꯤ ꯖꯒꯣꯏ ꯔꯥꯁ) recital was held at the Indo-American Arts Council in New York on 17th August 2011. The performance featured traditional Manipuri dance forms, representing the Meitei cultural heritage of the Indian state of Manipur. The event was part of the Council's efforts to promote Indian art and culture in the United States.
Leima Jagoi (Mtei ꯂꯩꯃ ꯖꯒꯣꯏ) and Thabal Chongba 
(Mtei ꯊꯥꯕꯜ ꯆꯣꯡꯕ) are traditional Meitei dance forms, notably performed by members of the American Meitei community during their meetings and summits. The performances serve as cultural expressions and are often included as parts of community gatherings and events.
 Festivals 
American Meitei people observe several traditional Meitei festivals, including Ningol Chakouba (Mtei ꯅꯤꯉꯣꯜ ꯆꯥꯀꯧꯕ), Yaoshang (Mtei ꯌꯥꯎꯁꯪ), Kang (Mtei ꯀꯥꯡ), Cheiraoba (Mtei ꯆꯩꯔꯥꯎꯕ), and Christmas.
 Media 
Kebola Wahengbam (Mtei ꯀꯦꯕꯣꯂꯥ ꯋꯥꯍꯦꯡꯕꯝ), based in Cincinnati, launched a YouTube channel dedicated to traditional Meitei cuisine, cooking, and gardening. She is one of the first American Manipuri women to establish a YouTube presence. Her channel occasionally features traditional Meitei attire and dance.
 Literature 
Second-generation and third-generation members of the diaspora may have limited proficiency in Meiteilon (Manipuri language) and are typically more comfortable with English.
On July 25, 2006, Laishram Sadananda, a retired Professor of Meitei literature (Manipuri literature), delivered a presentation titled "What is Manipuri Literature: An Overview of the Language and Literature of Manipur" at the New York Public Library. The event was organized by Dr. John M. Lundquist, Chief Librarian of the Asian and Middle Eastern Division, in collaboration with L. Somi Roy, a Manipuri-American media arts curator. This lecture marked the first presentation on Meitei literature outside of India.
L. Somi Roy introduced the event by discussing the digitizeMANIPUR! project, which he initiated with support from the Richard Gilder Foundation and Educate LLC.
Professor Sadananda's presentation included a detailed overview of both early and modern Meitei literature, emphasizing the language's Tibeto-Burman origins, its spread beyond Manipur, and the key categories of its literary works. He also provided examples of prominent texts and writers in modern Meitei literature. Additionally, he discussed the role of literary associations, publishing houses, and the academic teaching of Meitei literature, offering a comprehensive view of the literary landscape in Manipur.
 Religion 
Traditional Meitei religion
The majority of Meitei people in the United States follow Hindu Vaishnavism, while some adhere to Sanamahism, an indigenous religion characterized by ancestor worship.
 Remittances 
In mid-June 2020, the North American Manipur Association (NAMA) donated INR 1,87,150 to the Chief Minister's COVID-19 Relief Fund and to two orphanages in Manipur.
In July 2023, the Association of Meiteis in the Americas (AMA) donated essential commodities worth INR 16,50,000 to 36 relief camps across various districts in Manipur, with contributions from over 300 donors.
In August 2023, the North American Manipur Association (NAMA) raised INR 6,00,000 through a fundraising campaign for relief efforts in Manipur.
The funds were donated to the Manipur Governor’s relief fund to support displaced individuals in relief camps across the state. NAMA requested that the funds be used, either in whole or in part, to provide medical and sanitary assistance to women and children in the camps.
 Social services 
During the COVID-19 pandemic, American Meitei medical professionals used their stitching skills to produce hundreds of facemasks, which were donated to various healthcare and community centers, including Shattuck Hospital, Billerica Food Care, Franklin Senior Center, Beth Israel Hospital, Hockomock Area YMCA, the New Jersey State Adult Care Center, and New York State, as well as to friends, family, and other communities.
 Sports 
Traditional Meitei games
The North American Manipur Association (NAMA) seeks to preserve Meitei heritage by promoting the indigenous Meitei game of Kang (Mtei ꯀꯥꯡ), which is nearly extinct. It does not, however, focus on the traditional Meitei form of polo (Sagol Kangjei), an indigenous game from Manipur that has gained international recognition.
 Victims 
Jupiter Yambem was a Manipuri individual residing in the United States and was the only known Manipuri working at the World Trade Center during the terrorist attacks on September 11, 2001. He departed for work early that morning, following his usual routine. The last known communication with him was a phone call from his wife, Nancy. In the aftermath of the attacks, once phone lines were partially restored, calls to his mobile phone would ring but went unanswered.
Concern grew among his immediate family—his wife Nancy, son Shanti, and relatives in Imphal—as well as within the broader Manipuri community in the United States and elsewhere.
On September 16, 2001, five days after the collapse of the World Trade Center, his remains were recovered from the debris and identified by his wife.
A 25-year-old man originated from Manipur named Shaolin Chandam was shot on August 25, 2015, by a 24-year-old American named Keenan A. Palmer from Hampton.
 Associations and organizations 
The North American Manipuri Association (NAMA) was founded in 1991 in Brooklyn, New York, with no political ties or agenda.
The Association of Meiteis in the Americas (AMA) is a group of Meitei individuals across the Americas, focused on community and cultural engagement.
The North American Bangladesh Manipuri Society is a civil society organization with hundreds of Meitei members, mostly based in New York. The organization has participated in demonstrations urging the government to address "illegal immigration" in Manipur and to safeguard the state's territorial integrity.


Cognitive neuropsychology: Cognitive neuropsychology is a subject in psychology. It is a combination of biology and cognitive psychology. These psychologists study human behavior and knowledge. This is a growing subject. Unlike cognitive neuroscience, cognitive neuropsychology pays attention to the mind rather than the brain.
Many scientists have worked to make cognitive neuropsychology. Their findings have created an understanding of the brain and how humans learn and do things. Most of these scientists were not psychologists, but are known for their contributions to psychology. The technology today also helps advance what is known. With brain imaging and other methods the brain can now be visualized. Cognitive neuroscience can be broken into different topics such as memory, attention, language, and emotion.
History
Cognitive neuropsychology has its roots in research on language disorder that was done in the second half of the 19th century. One discovered that aphasia takes different forms depending on the (place or) location of brain damage; Knowledge from the research has been called a framework for understanding brain function (, or knowledge on which one has added additional (or more) knowledge).
The early history of cognitive neuropsychology begins with humans’ first acknowledgement of the mind/brain. Beliefs in the importance of the mind/brain/head emerge as early as 4000BC with the Sumerians. Records of Sumerian intake of the poppy plant (which contains opium) include descriptions of the mind-altering affects. This suggests a reference to the brain. Another clue pointing towards acknowledgement of the brain is the discovery of skulls with holes drilled into them in 2000BC. Discovery of these skulls points to the brain as important to life. The motivation behind these drillings could be spiritual or medical.
The greatest contribution to early cognitive neuropsychology came from Egypt in 1700BC. This is the time of the Edwin Smith Surgical Papyrus. This document has the first written description of the human brain. These writings include descriptions of meninges and cerebrospinal fluid. Ancient Greek philosophers Aristotle, Plato and Almaceon wrote about the form and function of the mind, psyche and soul. Aristotle saw the heart as the seat of the mind. He saw the heart containing all emotion and thinking. He also thought that the brain functioned to cool the heart down. Unlike Aristotle, Plato believed the brain to be the place for mental processes. With Aristotle we see the emergence of the dualistic view of mind and body. The dualistic versus monistic approach to the mind and brain is a debate dominating much of the history of cognitive neuroscience.
Galen was a Roman physician whose surgical descriptions of neurology helped describe the anatomy of the brain and neurological disorders. The Church was against human dissection. This limited the uncovering of new information. Many unskilled physicians attempted dissections in secret, but there were no real, scientific discoveries in anatomy for centuries..
 16th Century 
During the renaissance cognitive neuropsychology began to develop a deeper understanding of the brain. Vesalius wrote the first neuroscience textbook in 1543 and described the hydrocephalus in 1550. We also see the first use of the term “hippocampus” in 1564. This is when the brain was starting to be seen as a complex organ responsible for many operations of the body. René Descartes was the most well known figure in cognitive neuropsychology at this time. Some of Descartes’ contributions stemmed from his interest in the nervous system and brain’s role in behavior. He thought that the nervous system was made up of hollow tubes which filled with “animal spirits” any time an action were to take place in that part of the body. His other contributions included the more developed notion of dualism. He hypothesized that the brain and mind are two separate entities that exist on their own but are depend on each other. He theorized that the pineal gland in the brain is where these two separate entities interacted. Descartes’ dualistic theory serves as his most influential contribution to cognitive neuropsychology.
 18th Century 
During the 18th century science began to develop. The first big advance was in human reflexes. These bodily reactions to stimuli or outside forces were observed and measured. This was found by studying axons and learning how signals travel in the human body. The development of the microscope helped. The brain's nerve fibers could now be seen and described. Cerebrospinal fluid was found in the spaces of the brain and spinal cord. With that, the physiology of psychology began to take control of cognition. These findings are all still true today.
Electroconvulsion therapy or electric shock therapy was a method used to treat mental disorders. This was used to treat blindness, hysteria, depression, and many other disorders. It was thought to be the way of the future in treating disabilities.
 19th Century 
The 19th century started the argument of localism vs. holism in cognitive neuropsychology. People were starting to question holism and explore the idea of localism. Localism means that the brain has individual areas that are responsible for certain actions in the body. The study of Phrenology started these localization theories. Phrenology is looking at the human skull and finding bumps to be measured. Any strange bumps or shapes in the skull were then paired with intelligence or self traits in a person. These traits could include language, logic, and even love. If a part of the skull was pushed out it would mean that trait was better. This started localization theories 
The next big thing in cognitive neuroscience has to do with ablation studies. This is when parts of the brain were removed so function could be measured without this brain area. For example, a neuropsychologist can remove the cerebellum. After it is removed, the animal's balance was not good. This links the cerebellum to balance. As for brain damage, the most famous case is with Phineas Gage. He was working on the railroad when a piece of metal went through the front of his head. He did not die from this brain injury. However, his normal personality changed. This brought the idea that the frontal cortex, the part of the brain that was stabbed, controlled how a person acted. Another study found the localization of language in the brain. Two separate scientists studied patients with language problems. They found that they had lesions or damage in two certain areas of their brain. Broca's area controlled talking. Wernicke's area was found to control understanding of language.
This way of looking at problems in the brain led to studies of epileptic patients. An epileptic patient is a person that frequently suffers from seizures. These seizures were studied to learn more about how the brain sends electrical signals. These electrical signals were then measured. It was found that each neuron can send a signal at certain speeds. These neurons were then dyed with a stain in order to be seen. At first it was thought that all nerves were connected like a web called a nerve net. However, with more complex stain it was found that each nerve is separate and can fire on their own.
 20th Century 
John B. Watson, who was a behaviorist in psychology, argued that cognition could not be studied scientifically because it could not be observed. For the first half of the 20th century, psychology was dominated by behaviorism, which was mainly stimuli and a person’s response to it. Pierre Marie in 1906 criticized Broca, who was one of the first to create the field of Cognitive Neuropsychology. Henry Head in 1926 also attacked the whole field of cognitive neuropsychology. 
Another reason why cognitive neuropsychology disappeared in the early twentieth century was because the science was not yet advanced enough. Many cognitive psychologists were also neurologists. These two fields of study were not separate as they are today. These neurologists wanted to study modules in the brain, and localize them with parts of the brain, but technology did not allow this yet. The methods used today were not yet created. They could only study where a person’s brain lesion was by doing an autopsy after the person was dead. This was a reason this field was criticized, and why many people believed cognition could not be studied scientifically.
In the middle of the twentieth century there was a transition called the 'Cognitive Revolution' in psychology. This is when psychologists began to agree that there were scientific ways to study cognition. These new beliefs about cognitive psychology were brought on by John C. Marshall's and Nora Newcombe’s study of reading, and Shallice and Warrington’s study of memory in the early 1970s. In the mid 1980s the first undergraduate book was published by Ellis & Young named Human Cognitive Neuropsychology. There was also new technology that made it easier to study the brain and the mind. 
An important feature of the later half of the twentieth century was the clear separation of cognitive neuropsychology and cognitive neuroscience. Cognitive neuropsychologists study the human mind after brain damage has occurred, and focus more on cognition. Cognitive neuroscientists focus more attention on the neurons. While the cognitive neuroscientists are concerned with how the brain works, and what parts of the brain is responsible for what functions, cognitive neuropsychologists want to study people with brain damage to try and see how the human mind works. With this information, they can formulate theories about the human mind, and also make better therapies for people with brain damage. Since every person’s brain damage is different, cognitive neuropsychologists study only single cases instead of groups of people, or syndromes. Psychologists study the mind by looking at people who lost some sort of function after brain damage occurred. For example, if a person could recognize both faces and objects before brain damage occurred, but then after brain damage in a certain part of the brain they could only recognize faces and not objects, then psychologists can make inferences about the functions in certain modules of the brain.
The late 20th century was also when they began using computational models of cognition. The psychologists would make theories and install them into a computer, then virtually damage the fake brain where the patient had damage. By doing this, they can get a better look at how the mind works. This is one way that technology has helped in studying the human mind. This, along with the invention of the devices to scan the brain, has made a big difference in cognitive neuropsychology.
Cognitive neuropsychologists use the method of double dissociation when studying the modules of the mind. This is when they use many patients who have had brain damage and try to figure out which parts of the brain are responsible for different cognition. This concept of modularity was developed by Jerry Fodor in his 1983 book The Modularity of the Mind. Psychologists disagree as to how much and which parts of the mind is constructed modules.
 21st Century 
In this century, cognitive neuropsychologists use many methods to study the mind. They use machines that scan the brain to see where the damage is, and then study cognitive abilities of these patients. They still use double dissociation for studying the patients, case studies, computational models, and many other features that were invented in the late twentieth century. With new technology, there is likely to be a lot of improvement in this field.
 Tools used in cognitive neuropsychology 
Cognitive neuropsychology uses of investigations of people with problems of cognition to learn more about normal cognitive processes. This is possible through the many technological advances such as:
Lesion and Behavior Approaches 
EEG
Computerized Tomography (CAT) scan
Positron Emission Tomography (PET) scan 
MRI
fMRI


Abnormal psychology: November 2024November 2024
Abnormal psychology is a part of psychology which studies the minds of people who have a mental disorder. Abnormal behaviour is when someone is not able to change how they behave to fit different settings. This is often also used to define some mental disorders.
When someone cannot change their behaviour to fit the people and situations around them when they need to, it can cause distress and suffering. Their behaviour could be unreasonable or hard to understand. Their behaviour can even be dangerous. Not everyone with a mental disorder struggles to adjust to their surroundings.
History
Supernatural traditions
A supernatural belief is a belief in a force that is beyond scientific understanding. There are a lot of cultures that believe in supernatural events. These cultures include religious cultures, as well as the Ancient Chinese, Ancient Egyptians, Hebrews, and Ancient Greeks. These cultures have writings that say demons or Gods that would take over a person and act through those people. This was called possession. In the Roman Catholic Church, exorcisms were done to make these demons leave the body of the individuals they possessed. Exorcism involved prayer, noises and potions.p. 11 People who had abnormal behaviour were often told they were possessed.
In some cultures, trepanation was often used. This was when a hole was made in someone's head to release the "bad spirit".
Asylums
"Lunatic asylums" were buildings that kept patients that had abnormal behaviour. They became popular with the Madhouse Act of 1774, although they did exist before the Act. Asylums were meant to look after people who could not take care of themselves. But they were known for being cruel and abusive to their patients. The buildings were often dirty and not looked after very well.
During the late 1700s, William Tuke made a religious retreat for patients. This was a turn away from the horrors of mental asylums.p. 14 Also, in the late 1700s, Philippe Pinel started to encourage better treatment of the mentally insane.
Most of the big asylums were closed in the 20th century because of the invention of antipsychotic medicines. There are still psychiatric hospitals for people with mental illness. This includes Broadmoor Hospital, which houses some of Britain's most dangerous criminals with mental illnesses.
Asylums in America
In the 1800s, Dorothea Dix fought against the bad treatment of patients in mental asylums. She started a "mental hygiene" group to encourage politicians to change the treatment of mental patients in the United States. When people became aware of the wrongdoing in mental asylums, money was raised to improve the treatment of patients and the asylums. Dix is thought to have helped to create 32 mental hospitals. By 1940 there were more than 400,000 patients living in mental asylums.
Most treatments were still cruel to patients and were not effective. The asylums were quickly becoming overcrowded. Mary Jane Ward wrote a book in 1946 called "The Snake Pit" that raised awareness of the inhumane treatment of mental patients.
The National Institute of Mental Health was created the same year. The organisation provided training and support for mental patients and workers that cared for them. The Hill-Burton Act was passed to give money to the mental health hospitals.
Later, the Community Health Services Act of 1963 was passed. This law created buildings for patients to live at home rather than in hospitals. Rehabilitation and community care centers were also built under this act.p. 14
Deinstitutionalisation
During the late 1900s, mental asylums were less accepted. The cruel treatment of patients and the overcrowding and ways of living were seen as not needed. Less money was given to asylums. So many closed all around the world. The closing down of mental hospitals was called deinstitutionalization. The movement from asylum to community was meant to help patients' development and recovery. The lack of good support programs meant that patients felt abandoned and found it hard to fit into normal life. This led to many becoming homeless.p. 16
Explaining abnormal behaviour
In the past there were three ways to explain abnormal behaviour. These were supernatural, biological, and psychological explanations. Western medicine no longer uses supernatural explanations. It uses biological and psychological explanations. Biological explanations use genetics and neuroscience to explain abnormal behaviours. The biological explanation is based on how the brain works and how genes change the way it works. Psychological explanations use how the mind works to explain abnormal behaviours.
Supernatural explanations
Early cultures believed that abnormal behaviour was from demons, spirits and astrology. Trepanation was when a hole was drilled in a person's head. This was done to let the spirits or demons out of the person's head.
Exorcism was practiced mainly by the Catholic Church. Exorcism was believed to ward the spirits out of the person that they possessed.
These practices were normal during the Middle Ages. Abnormal behaviour was thought to be a religious issue rather than a psychological one. Some abnormal behaviour was thought to be witchcraft. People accused of witchcraft were almost always punished. In many cases, the punishment was to be murdered.
Biological explanations
The Biological approach to explaining abnormal behaviour assumes that the behaviour can be explained by physical factors. Hippocrates lived during the 5th century and is thought by many to be the father of modern medicine. He did not accept that evil spirits or astronomy were the causes of psychological disorders. Hippocrates believed that there were natural causes for the disorders and appropriate treatments could be found. He focused on the "four humors" of the brain. He believed that the four humours must be balanced for healthy mental states and when one humour was stronger, various disorders would appear. To balance the humors, Hippocrates would tell patients to change their lifestyles.p. 11 There are now new ideas when talking about the biological explanations of psychological disorders. But, Hippocrates' focus on mental processes and clinical practice was a big change.
Another Greek physician called Galen also took a scientific approach to the causes of psychological disorders. He divided them into physical and mental categories. Among Galen's causes were head injuries, alcohol abuse, and life experiences. During the 18th century, Galen's concepts influenced the medical industry. Galen's focus was on the biological causes for mental disorders.p. 13
Psychological explanations
Psychological explanations for abnormal behavior sometimes take a behavioral approach in which the positive behaviors are reinforced and negative ones are not. This approach is more focused on changing the actual behavior of a person than the cause of it.
Sigmund Freud was one of the most popular psychological theorists of the 20th century. The method he used to study and treat patients was known as psychoanalysis. Methods of hypnosis were used by Freud, but also by Franz Mesmer and physicians in the Nancy School. Freud attempted to have his patients confess their deepest, truest emotions, which was referred to as a catharsis. He would have his patients speak freely about themselves, in free association. He would conduct dream analysis where patients would record and discuss their dreams. Freud's work led to other great psychoanalytic theorists such as Carl Jung, Alfred Adler, and Harry Stack Sullivan. Wilhelm Wundt and William James were credited for opening up the first experimental psychology laboratories. This led to many studies and psychological methods, such as classical conditioning led by Ivan Pavlov and John B. Skinner, while Edward Thorndike and B. F. Skinner were the leaders of the study of operant conditioning.p. 18
Classification
DSM
The North American reference book used by psychiatrists and psychologists to diagnose and treat psychological disorders is known as the Diagnostic and Statistical Manual of Mental Disorders (DSM). It is produced by the American Psychiatric Association. The version released in May of 2013 and is known as the DSM-5. The DSM is relied upon by clinicians, health insurance companies, medicine companies, and the legal system as a reference for understanding and identifying mental disorders. The DSM divides mental disorders into groups and provides descriptive signs and symptoms that define each disorder. In addition, it lists statistics for each disorder ranging from its frequency in the general population to the most effective form of treatment
Before diagnosing an individual with a specific mental disorder, a professional must first determine whether that individual does in fact suffer from a mental disorder. The DSM defines a mental disorder as a condition that:
Is primarily psychological and alters behavior, personality, or motivation,
When in its full-blown state, causes stress, impairment in social functioning, or behavior that one would like to stop because it poses a threat to physical health, and
Is distinct from other conditions, and is considered treatable.
ICD-10
The International Statistical Classification of Diseases and Related Health Problems (ICD) was created by the World Health Organization and is the universal diagnostic system for mental disorders. The ICD is approved by health officials from 193 WHO member countries, and is available for free on the internet. Its purpose is to help countries reduce the problems associated with mental disorders. The coding system used in the DSM is designed to be compatible with the system used in the ICD; however, some codes may not match because the two publications get revised at different times. The ICD-10 was made public in 1994; its most recent update occurred in 2010. Chapter 5 of the ICD-10 covers over 300 mental and behavioral disorders which are divided into the following categories:
F00-F09 Organic mental disorders
F10-F19 Mental and behavioral disorders caused by drug use
F20-F29 Schizophrenia and delusional disorders
F30-39 Mood disorders
F40-49 Neurotic, stress-related disorders
F50-59 Behavioral disorders linked with bodily disturbances and physical factors
F60-F69 Disorders of adult personality and behavior
F70-F79 Mental retardation
F80-F89 Disorders of psychological development
F90-F98 Behavioral and emotional disorders that develop during childhood
F99 Unspecified mental disorders
The Online ICD-10 can be found in its entirety here
Treatment
Psychoanalysis
Psychoanalysis is a form of therapy based on psychoanalytic theory. This theory states that human behavior is controlled by unconscious forces such as instinct and that there is no such thing as free will. Many ideas found in the theory can be traced back to Sigmund Freud. Freud believed mental disorders are a result of repressed memories and emotions from childhood; psychoanalysis is designed to search for these hidden memories and emotions and bring them to the patient's attention. Techniques such as hypnosis are used to tap into the unconscious mind with the hopes that the source of the disturbance is found. Freud also believed dreams had hidden meanings, and often asked patients to record their dreams for analysis. Because of the lack of scientific evidence supporting most Freudian ideas, psychoanalysis is rarely used by clinical psychologists and has been replaced by more effective forms of therapy.
Behavioral therapy
Behavior therapy is based on the theory of behaviorism, which states that all human behavior is a result of a stimulus and reinforcement. Famous behaviorists include James Watson, B.F. Skinner, and Joseph Wolpe. The goal of this therapy is to increase one's positive or socially reinforcing behavior. Behavior therapy can be broken down into three areas:
Applied behavior analysis uses a form of operant conditioning where positive reinforcement is used to modify behavior.
Cognitive behavioral therapy focuses on conditioning the negative thoughts and feelings behind patients' behavior in order to alter that behavior.
 Social learning theory is used in the treatment and understanding of anxiety disorders. It goes beyond the traditional classical conditioning assumption that fear and anxiety must be learned directly; social learning theory suggests that a child could acquire a fear of snakes, for example, by observing a family member show fear in response to snakes.
 Humanistic therapy 
Humanistic therapy is a method taken from Carl Rogers, which aims to focus on a client as a human rather than the problem that they have. A therapist can adjust the environment and mood of a session in a way that mimics normal conversation. This often helps the patient realize the issues they have, and share them with the therapist more successfully than in a traditional counseling session. Humanistic therapy creates an effective means of getting to the source of a problem and treating it properly.
Roger's own term was "client-centered therapy", which has the idea that the therapist is helping the client to become a genuine psychological adult.


Philosophy of science: Philosophy of science is the part of philosophy that studies the sciences.
Philosophers who are interested in science study how knowledge is built up by scientists, and what makes science different from other activities. No doubt, modern science has advanced knowledge in a wide range of fields. How has it done this? To tackle this issue, a number of other issues also have to be tackled.
 What makes science distinct? 
Some people think that in earlier times, science was nothing but organized common sense. Thomas Henry Huxley thought this. However, during the twentieth century, science produced many ideas which were nothing like common sense, like general relativity. Then it was clear that science really was something different from common sense. But what was it? This is called the demarcation problem.
The demarcation problem refers to the distinction between science and non-science (like pseudoscience). Karl Popper called this the central question in the philosophy of science. No solution to the problem has had full agreement among philosophers; some of them think the problem is insoluble or uninteresting.
The logical positivists tried to base science on observation. In their view, truth was achieved by logic and observation. Non-science was non-observational and meaningless.
Against that, Popper argued that the central property of science is falsifiability. All scientific claims can be proved false, at least in principle. If no such proof can be found despite sufficient effort, then the claim is likely true. Popper's ideas were applauded by many scientists (like Peter Medawar). However, skeptics noticed that ideas were often not discarded when a prediction was refuted. The ideas were simply adjusted to take into account the new findings. It was clear from this that, although falsifiability was important, it could not be a simple way to distinguish science from non-science.
Other approaches were tried. One idea that science was a problem-solving process aimed at finding answers to questions. Of course, many other fields try to answer questions and solve problems. Another approach was to define science as the search for objective truth. But objectivity is very hard to define, and whether science really is objective is open to question.
With biology, the situation wasn't the same as other parts of science. There were thousands of published observations, and Darwin showed that sense could be made of the observations. He used those ideas to prove evolution had taken place. In a natural history science (such as biology, geology or astronomy), one of the main jobs of science is to explain what has happened and what is seen. Obviously, explanations as well as observations and theories are part of the philosophy of science.
 Theories and observations 
Both theory and observations are part of science, and they are tied together in a kind of cycle. A clear example was the prediction of Einstein that a source of gravity (such as a star) would bend light passing nearby. An expedition was organised in 1919 to record the positions of stars around the Sun during a solar eclipse. It showed that the positions of the stars close to the Sun were changed slightly from their normal expected positions. The light passing close to the Sun was pulled towards the sun by gravitation. This seemed to prove Einstein's general theory of relativity, published in 1915. Many years later, the proof was shown to be wrong. But by then other observations (of time dilation) showed that Einstein actually was right. Gravitational lensing proved that light was pulled towards the Sun.
The point here is that the observation and the theory were connected. The observation would not have been made but for the theory, and then the observation was convincing evidence in favour of the theory. The theory had passed a critical test. Since then, many more tests have been made of Einstein's ideas, and all have been consistent with his theory.
 A “naive” conception of science 
According to common sense, science begins with observations: all scientific knowledge come from the facts of experience. Theories are produced by observation of these facts and are then tested by prediction.
Here is a schema of this idea of science that some philosophers call a naive conception of science:
       ---> INDUCTION ---> LAWS AND THEORIES ---> DEDUCTION --->
       | |
       | |
       | |
 FACTS OF EXPERIENCE PREDICTIONS AND EXPLANATIONSFACTS OF EXPERIENCE
This naive conception is not held by many philosophers today. For one thing, it sees science as a one-way engine from 'facts' (what are they?) to theories and predictions. As shown by the Einstein example, where a theory led the other way round, the model does not fit much of science. In fact the relationship between the parts of a scientific philosophy are extremely complex.
 Testing a prediction 
According to Pierre Duhem and W.V. Quine, it is impossible to test a theory in isolation. For example, to test Newton's Law of Gravitation in our solar system, one needs information about the masses and positions of the Sun and all the planets. Famously, the failure to predict the orbit of Uranus in the 19th century did not lead to the rejection of Newton's Law. Instead, it lead to the rejection of the hypothesis that there are only seven planets in our solar system. The investigations that followed led to the discovery of an eighth planet, Neptune. If a test fails, something is wrong. But there is a problem in figuring out what that something is: a missing planet, badly calibrated test equipment, an unsuspected curvature of space, etc.
One consequence of the Duhem-Quine thesis is that any theory can be made compatible with any empirical observation by the addition of extra (ad hoc) hypotheses. This is why science uses Occam's Razor; hypotheses without justification are eliminated. This led Karl Popper, to reject naïve falsification in favor of 'survival of the fittest', or most falsifiable, of scientific theories. In Popper's view, any hypothesis that does not make testable predictions is simply not science. Such a hypothesis may be useful or valuable, but it cannot be said to be science. W.V. Quine thought that empirical data are not enough to make a judgment between theories. In this view, a theory can always be made to fit with the available empirical data. However, this does not necessarily imply that all theories are of equal value, because scientists often use guiding principles such as Occam's Razor.
One result of this view is that specialists in the philosophy of science stress the requirement that observations made for the purposes of science be restricted to intersubjective objects. That is, science is restricted to those areas where there is general agreement on the nature of the observations involved. It is comparatively easy to agree on observations of physical phenomena, harder to agree on observations of social or mental phenomena, and difficult in the extreme to reach agreement on matters of theology or ethics (and thus the latter remain outside the normal purview of science).
 Other ideas 
Critiques of scientific method
Is there any scientific method at all? Paul Feyerabend argued that no description of scientific method could possibly encompass all the approaches and methods used by scientists. Feyerabend objected to prescriptive scientific method on the grounds that any such method would stifle and cramp scientific progress. Feyerabend claimed, "the only principle that does not inhibit progress is: anything goes".
 Scientific revolutions 
Thomas Kuhn denied that it is ever possible to isolate the hypothesis being tested from the influence of the theory in which the observations are grounded. He argued that observations always rely on a specific paradigm, and that it is not possible to evaluate competing paradigms independently. By "paradigm" he meant a consistent "portrait" of the world, one that involves no logical contradictions and that is consistent with observations made from the point of view of the paradigm. More than one such logically consistent construct can paint a usable likeness of the world, but there is no common ground from which to pit two against each other, theory against theory. Neither is a standard by which the other can be judged. Instead, the question is which "portrait" is judged by some set of people to promise the most useful in terms of scientific "puzzle solving".
For Kuhn, the choice of paradigm was sustained by, but not ultimately determined by, logical processes. The individual's choice between paradigms involves setting two or more "portraits" against the world and deciding which likeness is most promising. In the case of a general acceptance of one paradigm or another, Kuhn believed that it represented the consensus of the community of scientists. Acceptance or rejection of some paradigm is, he argued, a social process as much as a logical process. Kuhn's position, however, is not one of relativism. According to Kuhn, a paradigm shift occurs when a number of observational anomalies (problems) in the old paradigm have made the new paradigm more useful. That is, the choice of a new paradigm is based on observations, even though those observations are made against the background of the old paradigm. A new paradigm is chosen because it does a better job of solving scientific problems than the old one.
The fact that observation is embedded in theory does not mean observations are irrelevant to science. Scientific understanding derives from observation, but the acceptance of scientific statements is dependent on the related theoretical paradigm as well as on observation. Of course, further testing may resolve differences of opinion.


Indianapolis Motor Speedway: The Indianapolis Motor Speedway (IMS) is in Speedway, Indiana (an enclave suburb of Indianapolis) in the United States. It is the home of the Indianapolis 500 race and formerly the home of the Brickyard 400 race.
It was built in 1909. It is the original Speedway, the first racing facility to use the word Speedway. IMS has permanent seating for more than 257,000 people. The infield raises capacity to approximately 400,000. It is the largest and highest-capacity sporting facility in the world.
The Speedway is considered relatively flat by American standards but high-banked by Europeans. It is a two and a half mile, nearly rectangular oval. Each of the four turns are 1/4 mile. Two 5/8 mile long straight connect turns 2 to 3 and turns 4 to 1. Two 1/8 mile short straights, termed short chutes, connect turns 1 to 2 and turns 3 to 4.
A modern infield road course was constructed between 1998 and 2000. It used part of the oval and the infield to create a 2.605 mi km on track. In 2008, the road course was changed to add another infield section. This is used for motorcycle racing, and is a 2.621 mi km on course.
On the grounds of the Speedway is the Indianapolis Motor Speedway Hall of Fame Museum, which opened in 1956. It is also the home of the Brickyard Crossing Golf Resort, which originally opened as the Speedway Golf Course in 1929.
Indianapolis Motor Speedway was placed on the National Register of Historic Places in 1975 and designated a National Historic Landmark in 1987.
In addition to the Indianapolis 500, the Speedway also hosted NASCAR's Brickyard 400 from 1994 to 2020. The Speedway also hosted the United States Grand Prix for Formula One from 2000 to 2007. In 2008, the Speedway added the Indianapolis motorcycle Grand Prix.
After winning his fifth United States Grand Prix at Indianapolis in 2006, Formula One driver Michael Schumacher holds the record for most victories with the Forumula One version of the road course. A.J. Foyt, Al Unser, Rick Mears and Helio Castroneves each won the Indianapolis 500 four times on the traditional oval. Jeff Gordon has also won four times on the oval in the Brickyard 400. Johnny Aitken holds the record for total wins at the track, with 15 victories (all on the oval), during the 1909, 1910 and 1916 seasons.
 History 
 Early history 
The first motorsports event at the track consisted of 7 motorcycle races, sanctioned by the Federation of American Motorcyclists (FAM), on August 14, 1909.
The first weekend of automobile races took place August 19–21, 1909. It was 16 races sanctioned by the American Automobile Association (AAA). The event almost turned into a disaster because of the surface of crushed stone and tar. There were several accidents and five fatalities. The final race of the weekend was halted after 235 mi km of its originally-scheduled 300 miles.
Carl G. Fisher, was an Indiana native, and both a former race car driver and one of the owners of the track. He led the work to make the track safer for the drivers and spectators. The track surface was paved with 3.2 million paving bricks. This gave the track its popular nickname The Brickyard. Today, 3 ft m (one yard) of the original bricks remain at the start/finish line., still giving meaning to the 'brick yard'. The final brick added to the roadway was a gold plated brick and laid by Governor Thomas R. Marshall on December 17, 1909.
The Speedway reopened in 1910. Sixty-six automobile races were held during three holiday weekends (Memorial Day, Fourth of July and Labor Day). Each weekend featured two or three races of 100 mi km on to 200 mi km on distance. Several shorter contests were also held. Each race was its own event and earned its own trophy. All races were sanctioned by the AAA. In 1911, a change in marketing focus led to holding only one race per year.
An estimated 80,000 spectators came to the first Indianapolis 500 Mile Race on Memorial Day May 30, 1911. Admission was one dollar. Ray Harroun won the race at the average speed of 74.602 mph (120.060 km/h).
The next five Indianapolis 500 were held from 1912–1916. Three of the Indy 500 winners were Europeans. These races drew worldwide attention to the Speedway. More international drivers began to enter.
The 1916 race was shortened to 120 laps for 300 mi km. Several things caused the race to be shortened . There was a lack of entries from Europe and a lack of oil. Another reason was out of respect for the war in Europe.
On September 9, 1916, the Speedway hosted a day of short racing events. These were called the Harvest Classic. There were three races held at 20, 50 and 100 mi km on distances. Johnny Aitken, in a Peugeot, won all three events, his final victories at the track. After the Harvest Classic, no race other than the Indianapolis 500 to be held on the grounds for seventy-eight years.
Racing was interrupted in 1917–1918 by World War I. The facility served as a military center for repairs.
Racing resumed in 1919. Speeds quickly increased. In 1925 Peter DePaolo became the first to average 100 mph (160 km/h) for the race.
By the early 1930s, the increasing speeds began to make the track more dangerous. In the period 1931–1935 there were 15 fatalities. Part of the bricks were replaced with tarmac (a tar covered macadam or small stones). During the 1935–1936 seasons a number of changes were made. The inside wall was removed in the corners. The outside wall angle was changed to help keep cars inside the track. Hard crash helmets became required. The first yellow lights were installed around the track.
 1940s: Start of the Hulman Era 
At the beginning of the 1940s, the track needed more improvement. In 1941, half of the garage area, known as Gasoline Alley, burned down before the race. When the United States joined World War II, the 1942 race was canceled. In 1942 all auto racing was banned. The 500-Mile Race was canceled for the years 1942–1945. The track mostly abandoned during the war years.
On November 29, 1944, three-time 500 winner Wilbur Shaw came back to do a 500 mi km on tire test for Firestone. The test was approved by the government. Shaw found the track to be in very bad condition. He contacted the owner, Eddie Rickenbacker, and found that the Speedway was for sale. Shaw tried to find a buyer that would keep the Speedway as a race track. He found Indiana businessman Tony Hulman. The Speedway was purchased on November 14, 1945.
Major renovations and repairs were made to the Speedway. It opened in time for the 1946 race. Many improvements have been made since 1946.
The 500-Mile Race became part of the Formula One World Championship for 11 years (1950–1960). None of the regular Indy drivers raced in Formula One. Alberto Ascari from Ferrari was the only F1 driver to race in the 500 during this time.
In October 1961, the final remaining brick sections of the track were paved over with asphalt, with the exception of a distinct three-foot-wide line of bricks at the start/finish line. The "Brickyard" thus became known for its "Yard of Bricks".
 NASCAR IROC and Indy Lights at Indy 
From 1919 to 1993, the 500 was the only race run at the Brickyard. Tony George (Hulman's grandson) inherited the track. He brought more racing to the Speedway. NASCAR started racing in 1994 with the Brickyard 400. The International Race of Champions (IROC) event was added in 1998. The last IROC at Indy race was held in 2003.
In 2003, the Firestone Indy Lights Series, a minor league series of the Indy Racing League, started racing at the Speedway. They were the first series to race in May other than the 500 since 1910.
 Formula One and road course racing 
In 1998, Tony George made a deal to bring Formula One back to the United States. The last time F1 raced in the US was 1991. A new Indy-based road course using part of the oval track, and part of the infield was built in two years. The first United States Grand Prix held at the Speedway was in 2000. The 2001 event reported 185,000 fans were reported in attendance. The success was even more important with the race. The race was held on September 30, 2001. It was the largest international sporting event held in the United States after September 11, 2001 terrorist attacks.
Unlike the oval track, the Grand Prix road course is raced in a clockwise direction. This follows the general practice of Formula One, in where most circuits run clockwise.
On July 12, 2007, it was announced that Formula One would not return to the Speedway for 2008. Tony George said there were problems meeting the demands of Bernie Ecclestone to continue hosting the event. On May 25, 2010 it was announced that Formula One would return to the United States in 2012 at a new purpose-built track in Austin, Texas.
 Tire problems 
In 2005, there was a big problem with some of the Formula One tires. During practice, there was a big crash at turn 13. This part of the F1 circuit is the turn 1 of the oval track. This is also the only banked corner on the F1 calendar. Michelin realized their tires could not handle the banking. They would fail after a few laps. The cars using Bridgestone tires did not have the problem.
The Michelin teams could not solve the problem. Michelin wanted to add a chicane before the turn. The FIA would not allow the track to be modified. Everyone involved tried to fix the problem right up to race. Michelin told their teams the tires were not safe to race with.
The Michelin teams lined up on the starting grid. They drove around the track for the slow parade lap. At the end of the lap, they pulled into the pits and parked their cars. This left only the three Bridgestone teams (six race cars) to run the race. The two Ferrari cars were the only cars on the lead lap at the end of the race.
 Motorcycle racing and a new road course 
On July 16, 2007, the Speedway announced that it would host a round of Grand Prix motorcycle racing beginning in 2008. The race was backed by Red Bull and known as the Red Bull Indianapolis GP. This was the first motorcycle racing event at the facility since its first month of operation, in August 1909.
Modifications approved by the FIA and FIM were made to the former Formula One circuit. The new circuit now has 16 turns. The motorcycle course runs counter-clockwise, the same direction as the oval track. It bypass the banking of the oval with a new infield section inside Turn 1. Also, the double-hairpin at the Hulman Straight was replaced with traditional S-turns. The construction was finished before the opening day of the 2008 Indianapolis 500.
 Other sporting events 
The city of Indianapolis has hosted a half-marathon. It includes one lap around the Speedway.
The Speedway Golf Course has hosted a PGA Tour event and an LPGA event. A Champions Tour event was hosted there from 1994–1999.
At the 1987 Pan American Games, the speedway hosted opening ceremonies and the speed roller skating competition.
IMS was used to host events when Indianapolis hosted Super Bowl XLVI in February 2012.
 Speed records 
Indianapolis 500
Brickyard 400
United States Grand Prix
{| class="wikitable"
|-
!Type
!Distance(mi) (km)
!Date
!Driver
!Time
!Average speed(mph) (km/h)|-
| style="text-align:center;"| Practice (1 lap)
| style="text-align:center;"| 2.605 4.192
| style="text-align:center;"| June 19, 2004
|| Brazil Rubens Barrichello
| style="text-align:center;"| 0:01:09.454
| style="text-align:center;"| 135.025 217.301
|-
| style="text-align:center;"| Qualifying(1 lap)
| style="text-align:center;"| 2.605 4.192
| style="text-align:center;"| June 19, 2004
|| Brazil Rubens Barrichello
| style="text-align:center;"| 0:01:10.223
| style="text-align:center;"| 133.546 214.921
|-
| style="text-align:center;"| Race(1 lap)
| style="text-align:center;"| 2.605 4.192
| style="text-align:center;"| June 20, 2004
|| Brazil Rubens Barrichello
| style="text-align:center;"| 0:01:10.399
| style="text-align:center;"| 133.207 214.375
|-
| style="text-align:center;"| Race(73 laps)
| style="text-align:center;"| 190.165 306.041
| style="text-align:center;"| June 19, 2005
|| Germany Michael Schumacher
| style="text-align:center;"| 1:29:43.181
| style="text-align:center;"| 127.173 204.665
|-
|colspan="6"| All-time track record for the IMS original (2000–2007) road course
|}Red Bull Indianapolis GP'''
 Oval dimensions


Science fiction: November 2011
SF the Californian city San Francisco
Science fiction (often shortened to sci-fi or SF) is a genre of speculative fiction which deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, interstellar travel, parallel universes, and extraterrestrial life. It has been called the "literature of ideas", and it often explores the potential consequences of scientific, social, and technological innovations. Science fiction stories can be novels, movies, TV shows, video games, comic books and other literature.
SF is often about the future. It can be about imaginary new science and inventions such as spaceships, aliens, and robots. Science fiction stories are often in a world that is very different from the real world. They can have science and tools that do not exist in reality. Science fiction stories often take place on other worlds. There are often alien creatures.
Science fiction is drastically different from fantasy. Fantasy stories often have magic and other things that do not exist and are not science. Isaac Asimov was a famous science fiction writer. He once said that science fiction is possible, but fantasy is not.
Writers often use SF to explain everyday questions or problems by putting them in the future. Usually they invent a very different world to help people notice important ideas.
 Early examples of science fiction 
Science fiction changes over time. Some authors wrote SF books before this type of writing had a name. These writers and books were not called science fiction when they were published. But, they are often called science fiction today.
 Mary Shelley – Frankenstein (1818)
 Jules Verne – Twenty Thousand Leagues Under the Sea (1870)
 H. G. Wells – The Time Machine (1895).
 20th century science fiction 
 Isaac Asimov, Robert A. Heinlein and Arthur C. Clarke are seen as the big three science fiction authors of the 20th century.
 Philip K. Dick, Poul Anderson and William Gibson are other well-known science fiction authors from the 20th century.
 Star Trek – a 1960s American TV show that led to a media franchise.
 Doctor Who – a long-running British TV show.
 Star Wars -a trilogy of movies preceded by a novel that turned into a media franchise
 Different types of science fiction 
Two broad genres of science fiction are Hard SF and Soft SF. Although not everyone agrees on the exact definitions of these two types, the way they use science or the type of science used in the stories is different.
Hard SF
Hard science fiction, or "hard SF", is special because it uses true facts and theories from sciences. These sciences are very important in Hard SF: physics, astrophysics, and chemistry. Also, Hard SF can show worlds that more advanced technology may make possible. Many correct predictions of the future come from the hard science fiction subgenre. However, there have been many incorrect ideas about the future, too. Some hard SF writers have also worked as professional scientists. A few of these scientist/writers are Gregory Benford and Geoffrey A. Landis, while mathematician authors include Rudy Rucker and Vernor Vinge. Other noteworthy hard SF authors include Arthur C. Clarke, Hal Clement, Isaac Asimov, Greg Bear, Stanislav Lem, Larry Niven, Robert J. Sawyer, Stephen Baxter, Alastair Reynolds, Charles Sheffield, and Greg Egan.
Soft SF
Soft science fiction stories take ideas from social sciences such as psychology, economics, political science, sociology, and anthropology. Some important writers in this category include Ursula K. Le Guin and Philip K. Dick. Soft SF can be mostly about character and emotion. Ray Bradbury won a prize called the SFWA Grand Master and writes in this style. The Soviet Union produced social science fiction too. Some examples are Strugatsky brothers, Kir Bulychov and Ivan Yefremov.
Some Social SF and Soft SF can be types of speculative fiction, for example utopian or dystopian stories. George Orwell's Nineteen Eighty-Four, Aldous Huxley's Brave New World and Margaret Atwood's The Handmaid's Tale, are examples. Some people think that satirical novels in fantastic settings (places) such as Gulliver's Travels by Jonathan Swift are speculative fiction.
Different styles of science fiction
Within Hard or Soft SF, there are different types, or subgenres, of science fiction. Each subgenre is a group of stories that uses similar ideas or styles of story-telling. Publishing companies and critics put works of SF into different subgenres to help describe the work to help readers choose which books to read or movies to watch. Assigning genres is not simple. Some stories can be in two or more genres at the same time. Other stories may not fit any genre.
Alternate history
In Alternate (or alternative) history stories, writers imagine how the past might have been different. These stories may use time travel to change the past. Some set a story in a universe with a different history from our own. These are some important alternate history books:
 Bring the Jubilee by Ward Moore - the South won the American Civil War
 The Man in the High Castle by Philip K. Dick - Germany and Japan won World War II.
The Sidewise Award is for the best works in this subgenre. The name Sidewise is taken from Murray Leinster's 1934 story "Sidewise in Time." Harry Turtledove is one of the most famous writers in the subgenre. He is often called the "master of alternate history".
Apocalyptic
Apocalyptic fiction is about the end of civilization. There are several types: through war (On The Beach), pandemic (The Last Man), astronomic impact (When Worlds Collide), ecological disaster (The Wind From Nowhere), or mankind's self-destruction (Oryx and Crake), or some other general disaster. Apocalyptic SF may also be about world or civilization after a disaster.
Cyberpunk
Cyberpunk began in the early 1980s. Bruce Bethke used this word as the title for a short story in 1980 by putting together two words: "cybernetics" and "punk". Soon, people used this word to describe William Gibson's book, Neuromancer. Cyberpunk authors can put their stories in different settings. Stories usually take place in the near-future and the settings are often dystopian (characterized by misery). These are often societies with very advanced technology. A few huge corporations usually control the society. Another early cyberpunk novel that has become a classic is Snow Crash by Neal Stephenson.
Military science fiction
Military science fiction stories happen during wars. These wars can be between different countries, different planets, or between different species. The stories are told by characters who are soldiers. They include detail about military technology, rules, and history. Some Military SF may be similar to real historical conflicts. Heinlein's Starship Troopers is an early example. Another is the Dorsai novels of Gordon Dickson. Joe Haldeman's The Forever War is a response to the World War II–style stories of earlier military SF authors. Haldeman was a soldier in the Vietnam War. Important military SF authors include John Ringo, David Drake, David Weber, and S. M. Stirling. Baen Books is known for cultivating military science fiction authors.
Maritime science fiction
Maritime science fiction is science fiction that features a maritime or marine environment and technology and/or marine lifeforms mixed with science fiction. The probably earliest form of maritime science fiction literature is 20,000 Leagues Under the Sea.
Superhuman
Superhuman stories are about humans who get special abilities that are not normal. Maybe the new powers come from nature. Two examples of this type are Olaf Stapledon's novel Odd John and Theodore Sturgeon's More Than Human. Sometimes scientists give people special powers on purpose. one example is A.E. van Vogt's novel Slan. Frederik Pohl's novel Man Plus is another good example from this category. In that book, government scientists make a man into a powerful cyborg (part human, part machine).
These stories usually have two main points. One is the feeling of loneliness and separation that these superhuman people feel. The other is society's reaction to them.
Space opera
Space opera is adventure science fiction in outer space or on distant planets. Action is more important than the science or characters. There is usually a strong hero and a very big conflict. The action often moves to many different places. Edward E. (Doc) Smith was an early Space opera writer. Flash Gordon and Star Wars are also popular examples.
Space western
Space western takes ideas from books and movies about exploring the American Old West and moves them to space in the future. These stories are often on "frontier" colony worlds (colonies that have only recently been terraformed and/or settled) serving as stand-ins for the backdrop of lawlessness and economic expansion that were predominant in the American west. Some examples are Firefly and the movie Serenity by Joss Whedon. Anime programs like Cowboy Bebop and Outlaw Star are also Space Westerns. Han Solo from "Star Wars" is an important Space Western character.
Time travel
The first important time travel novel was Mark Twain's A Connecticut Yankee in King Arthur's Court. The most famous is H. G. Wells's 1895 novel The Time Machine. Well's book uses a machine that allows an operator to travel to an exact time. Twain's time traveler is struck in the head and wakes up in the past. The term "time machine" was invented by Wells. Now it is the name for any vehicle that can take a rider to another time. Ray Bradbury's 1952 short story called A Sound of Thunder is a more recent and very famous example of this genre. Time travel stories can be complicated. They have logical problems such as the grandfather paradox. Time travel is a popular subject in modern science fiction, in print, movies, and television.
Other sub-genres
 Comic science fiction is a sub-genre of science fiction that is more humorous or funny.
 Feminist science fiction asks questions about society. How does society make gender roles? How does having children define gender? Does having children change the political and personal power of men and women? Some well-known feminist science fiction stories use utopias to answer those questions. The stories explore a society in which gender differences or gender power imbalances do not exist. Also dystopias can explore worlds in which gender inequalities are stronger. Those dystopias explain that feminist work should continue. See Ursula K. Le Guin, Margaret Atwood
 Libertarian science fiction is written from a political point of view. This subgenre uses fiction to explore ideas from libertarian political philosophy about government and social organization. A classic example of libertarian science fiction is The Moon is a Harsh Mistress by Robert Heinlein.
 New Wave is science fiction writing with a lot of experimentation. Writers try new ways of writing and new story ideas. It may feel more intellectual. New Wave seems more like important "literature" or art.
 Steampunk is the idea of future technology in the past. These stories are usually in the 19th century and often in Victorian era England. Steampunk stories have strong images from either science fiction or fantasy. Steampunk can have imaginary inventions like those found in books by H. G. Wells and Jules Verne. Imagining a world where computers were invented a long time ago is also popular. Examples include The Difference Engine by William Gibson and Bruce Sterling, and the Girl Genius series by Phil and Kaja Foglio. The start of this style may be seen in some writing by Michael Moorcock, Philip Jose Farmer and Steve Stiles. Games like Space 1889 and Marcus Rowland's Forgotten Futures can also be Steampunk. The name comes from the fact that machines are most often powered by steam in this genre.
 Biopunk is like cyberpunk, but instead of focusing on cybernetic technology, it focuses on biotechnology.
 Mundane science fiction is science fiction set on a fiction Earth and not involving any space travel or extraterrestrial elements. Jurassic Park is considered and example of mundane science fiction.
 Speculative Evolution (Spec Evo) is a subgenre of science fiction, that hypothesizes the evolution of life, often following one planet and branching species.
Notable science fiction writers
Frank Herbert author of the Dune series.
Isaac Asimov author of the Foundation series.
Marion Zimmer Bradley author of the Darkover series.
Arthur C. Clarke author of a number of classic science fiction novels
Fandom and community
Science fiction fandom is the "community of the literature of ideas... the culture in which new ideas emerge and grow before being released into society at large". Members of this community, "fans", are in contact with each other at conventions or clubs, through print or online fanzines, or on the Internet using web sites, mailing lists, and other resources.
SF fandom emerged from the letters column in Amazing Stories magazine. Soon fans began writing letters to each other, and then grouping their comments together in informal publications that became known as fanzines. Once they were in regular contact, fans wanted to meet each other, and they organized local clubs. In the 1930s, the first science fiction conventions gathered fans from a wider area. Conventions, clubs, and fanzines were the main fan activities, or "fanac", for decades, until the Internet improved communication among a much larger population of interested people.
Awards
There are two very important science fiction awards: the Hugo Award and the Nebula Award. The Hugo is presented by the World Science Fiction Society at Worldcon each year. The Nebula is presented by SFWA and voted on by the community of authors. One important award for science fiction movies is the Saturn Award. The Academy of Science Fiction, Fantasy, and Horror movies gives this award each year..
There are national awards, like Canada's Aurora Award and the UK Arthur C. Clarke Award, regional awards, like the Endeavour Award presented at Orycon for works from the Pacific Northwest, special interest or subgenre awards like the Chesley Award for art or the World Fantasy Award for fantasy. Magazines may organize reader polls, notably the Locus Award.
Conventions, clubs, and organizations
Conventions (in fandom, shortened as "cons"), are held in cities around the world, catering to a local, regional, national, or international membership. General-interest conventions cover all aspects of science fiction, while others focus on a particular interest like media fandom, filking, etc. Most are organized by volunteers in non-profit groups, though most media-oriented events are organized by commercial promoters. The convention's activities are called the "program", which may include panel discussions, readings, autograph sessions, costume masquerades, and other events. Activities that occur throughout the convention are not part of the program; these commonly include a dealer's room, art show, and hospitality lounge (or "con suites").
Conventions may host award ceremonies. Worldcons present the Hugo Awards each year. SF societies are a year-round base of activities for science fiction fans. They may be associated with an ongoing science fiction convention, or have regular club meetings, or both. Most groups meet in libraries, schools and universities, community centers, pubs or restaurants, or the homes of individual members. Long-established groups like the New England Science Fiction Association and the Los Angeles Science Fantasy Society have clubhouses for meetings and storage of convention supplies and research materials.
The Science Fiction and Fantasy Writers of America (SFWA) was founded by Damon Knight in 1965 as a non-profit organization to serve the community of professional science fiction authors, 24 years after his essay "Unite or Fie!" had led to the organization of the National Fantasy Fan Federation. Fandom has helped support related groups as they started to form, including media fandom, the Society for Creative Anachronism, gaming, filking, and furry fandom.
Fanzines and online fandom
The first science fiction fanzine, The Comet, was published in 1930. Fanzine printing methods have changed over the decades, from the mimeograph and the ditto machine, to modern photocopying. The number of copies was usually not enough to use commercial printing. Modern fanzines are printed on computer printers or at local copy shops, or they may only be sent as email. The best known fanzine (or "'zine") today is Ansible''. David Langford is the editor and it has won several Hugo awards. Artists working for fanzines have risen to prominence in the field, including Brad W. Foster, Teddy Harvia, and Joe Mayhew; the Hugos include a category for Best Fan Artists. The earliest organized fandom online was the SF Lovers https://web.archive.org/web/20061223120718/http://www.noreascon.org/users/sflovers/u1/web/ 2006-12-23 community, originally a mailing list in the late 1970s with a text archive file that was updated regularly. In the 1980s, Usenet groups greatly expanded the circle of fans online. In the 1990s, the development of the World-Wide Web made the online fan community much, much larger. Fans created thousands and then millions of web sites devoted to science fiction and related genres for all media. Most of these websites are small, ephemeral, or about very specific topics. Though sites like SF Site and Read and Find Out give readers a broad range of references and reviews about science fiction.
Fan fiction
Fan fiction is non-commercial fiction created by people who love an SF story or world. Fans write stories that take place in the setting of an established book, movie, or television series. Some people call it "fanfic". In some cases, the copyright owners of the books, movies, or television series have instructed their lawyers to issue "cease and desist" letters to fans.


Atomic physics: Atomic physics is the field of physics studying atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons within the atom and the processes by which it changes. This includes ions as well as neutral atoms.December 2024
The term atomic physics is often associated with nuclear power and nuclear bombs, due to the synonymous use of atomic and nuclear in standard English. However, physicists distinguish between atomic physics, which deals with the atom as a system consisting of a nucleus and electrons, and nuclear physics, deeming atomic nuclei alone.December 2024
As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider context of atomic, molecular and optical physics. Physics' research groups are usually so classified.December 2024December 2024
Isolated atoms
Atomic physics often considers atoms one by one. Atomic models will consist of a single nucleus that may be surrounded by one or more bound electrons. It is not concerned with the formation of molecules, though much of the physics is identical, nor does it examine atoms in a solid state as condensed matter. It is concerned with processes such as ionization and excitation by photons or collisions with atomic particles.
While modelling atoms in isolation may not seem realistic, if one considers atoms in a gas or plasma then the time-scales for atom-atom interactions are huge in comparison to the atomic processes that are generally considered. This means that the individual atoms can be treated as if each were in isolation, as the vast majority of the time they are. By this consideration atomic physics provides the underlying theory in plasma physics and atmospheric physics, though both deal with very large amount of atoms.
Electronic configuration
Electrons form notional shells around the nucleus of an atom. These are naturally in a ground state but can be excited by the energy absorption from light, or photons, magnetic flux, atomic or molecular collision. The energy required to remove an electron from its shell is called the binding energy. An amount of energy absorbed by the electron more than such amount is converted to kinetic energy according to the law of conservation of energy. An atom with an electron removed is said to have gone through ionization.December 2024 Meanwhile, it is important to note that binding energy is not the same as ionization energy in that binding energy is the energy required to remove all electrons from an atom or ion while ionization energy is the energy required to remove an outermost shell electron to infinity.
In the event of electron's absorption of energy less than the binding energy, it will transition to an excited state. After a statistically sufficient amount of time,December 2024 an electron in an excited state will undergo a transition to a lower state. The change in energy between the two energy levels must be accounted for. In a neutral atom,December 2024 the system will emit a photon of the difference in energy.December 2024 
However, if the excited atom has been previously ionized, in particular if one of its inner shell electrons has been removed, a phenomenon known as the Auger effect may take place where the amount of energy is passed on to one of the bound electrons causing it to go into the continuum,December 2024December 2024 allowing one to multiplyDecember 2024 ionize an atom with a single photon. There are rather strict selection rules as to the electronic configurations that can be reached by excitation by light. However, there are no such excitation rules by collision processes.December 2024December 2024
History and developments
The majority of fields in physics can be divided between theoretical work and experimental work, and atomic physics is no exception. It is usually the case, but not always, that progress goes in alternate cycles from an experimental observation, through to a theoretical explanation followed by some predictions that may or may not be confirmed by experiment, and so on. Of course, the current state of technology at any given time can put limitations on what can be achieved experimentally and theoretically so it may take considerable time for theory to be refined.
One of the earliest steps towards atomic physics was the recognition that matter was composed of atoms, in the modern sense of the basic unit of a chemical element. This theory was developed by the British chemist and physicist John Dalton in the 18th century. At this stage, it wasn't clear what atoms were although they could be described and classified by their properties macroscopically in a periodic table. The true beginning of atomic physics is marked by the discovery of spectral lines and attempts to describe the phenomenon, most notably by Joseph von Fraunhofer.December 2024
The study of these lines led to the Bohr model and to the birth of quantum mechanics. In seeking to explain atomic spectra an entirely new mathematical model of matter was revealed. As far as atoms and their electron shells were concerned, not only did this yield a better overall description, i.e. the atomic orbital model, but it also provided a new theoretical basis for the chemistry's fields of quantum chemistry and atomic spectroscopy.
Since World War II, both theoretical and experimental fields have advanced at a rapid pace. This can be attributed to progress in computing technology, which has allowed larger and more sophisticated models of atomic structure and associated collision processes.December 2024 Similar technological advances in accelerators, detectors, magnetic field generation and lasers have greatly assisted experimental work.
Significant atomic physicists
 Pre quantum mechanics
 John Dalton
 J.J. Thomson
 Johannes Rydberg
 Joseph von Fraunhofer
 Post quantum mechanics
 Niels Bohr
 Max Born
 David Bates
 Enrico Fermi
 Vladimir Fock
 Alexander Dalgarno
 Clinton Joseph Davisson
 Charlotte Froese Fischer
 Nevill Mott
 Ratko Janev
 Mike Seaton
 John C. Slater
 Douglas Hartree
 Harrie S. Massey
 Ernest M. Henley
 George Paget Thomson


History of philosophy: The history of philosophy is the systematic study of the development of philosophical thought. It focuses on philosophy as rational examination based on arguing, but some people also include myth and religious traditions.
Western philosophy started with a question about the basic nature of the outer space in Ancient Greece. Later philosophical developments covered several different topics including the nature of reality and the mind, how people should act, and how to arrive at knowledge. The medieval period was focused more on theology. The Renaissance period saw a renewed interest in Ancient Greek philosophy and the coming of humanism. The modern period was seen as an increased focus on how philosophical and scientific knowledge is created. Its new ideas were used during the Enlightenment period to challenge traditional people in charge. Important developments in the 19th and 20th centuries included German idealism, pragmatism, positivism, formal logic, linguistic analysis, phenomenology, existentialism, and postmodernism.
 Western 
Western philosophy refers to the philosophical traditions and ideas connected with the area and cultural history of the Western world. It started in Ancient Greece and later expanded to the Roman Empire. After that, it spread to Western Europe and eventually reaching other areas, including North America, Latin America, and Australia. Spanning over 2,500 years, Western philosophy began in the 6th century BCE and continues to change today.
 Ancient 
Western philosophy originated in Ancient Greece in the 6th century BCE. This period is ordinarily believed to have ended in 529 CE when the Platonic Academy and other philosophical schools in Athens were closed by order of the Byzantine Emperor Justinian I, who tried to hold down and stop non-Christian teachings.
 Presocratic 
The first period of Ancient Greek philosophy is called Presocratic philosophy. It lasted until about the mid-4th century BCE. Studying Presocratic philosophy is difficult because many original writings have been lost. Today, we only know about them through quotes in later works.
A key idea of Presocratic philosophy was trying to explain the cosmos (the universe) using reason instead of Greek mythology. In Greek myths, gods like Uranus and Gaia were believed to control the world. Presocratic philosophers challenged these ideas and looked for natural explanations for how the world was created and how it works.
Some early philosophers are:
 Thales of Miletus (c. 624–545 BCE) is often called the first philosopher. He believed that everything came from water.
 Anaximander (c. 610–545 BCE) thought that the universe came from something infinite and undefined, which he called the apeiron (meaning "the boundless").
One of the topics discused during this period was change and stability:
 Heraclitus (c. 540–480 BCE) believed that everything is always changing. He said, "You cannot step into the same river twice." He also introduced the idea of logos, a guiding principle that brings order to the world.
 Parmenides (c. 515–450 BCE) disagreed. He argued that true reality never changes and is always the same.
 Zeno of Elea (c. 490–430 BCE), a student of Parmenides, created paradoxes to show that motion and change are illusions. One of his famous ideas is Achilles and the Tortoise, which suggests that a faster runner can never catch up to a slower one if the slower runner has a small head start.
The idea of atoms
 Democritus (c. 460–370 BCE) introduced the idea of atomism. He believed that everything is made of tiny, indivisible particles called atoms.
Other important Presocratic philosophers include Anaximenes, Pythagoras, Xenophanes, Empedocles, Anaxagoras, Leucippus, and the sophists, such as Protagoras and Gorgias.
 Socrates, Plato, and Aristotle 
The philosophy of Socrates (469–399 BCE) and Plato (427–347 BCE) built on Presocratic philosophy but introduced new ideas and ways of thinking.
Socrates did not write anything himself. What we know about him comes from the writings of others, especially his student Plato. Socrates used a special method of questioning, known as the Socratic method, to explore topics and challenge people's ideas. He asked simple questions to make people think deeply and understand their own ignorance.
Unlike the Presocratics, who studied the natural world, Socrates focused on moral philosophy. He asked questions about what it means to live a good life and examined virtues like justice, courage, and wisdom. Even though he was a great teacher of ethics, he did not tell people what to believe. Instead, he encouraged them to think for themselves.
Most of what we know about Socrates comes from Plato’s writings. Plato wrote his ideas in Socratic dialogues, where different characters discuss philosophy. Because of this, it is sometimes hard to tell which ideas belonged to Socrates and which were Plato's own.
Plato introduced the theory of forms, which says that the real world is made of eternal and perfect ideas (or "Forms"). Things we see, like trees or animals, are just imperfect copies of these ideal Forms. This idea influenced many later thinkers in metaphysics and epistemology.
Plato also contributed to psychology, saying that the soul has three parts: reason, spirit, and desire. These parts interact to shape human behavior. He also wrote about ethics and political philosophy, imagining an ideal society ruled by philosopher-kings in his book The Republic.
Plato founded the Academy, one of the first schools of higher learning, where he taught students like Aristotle.
Aristotle (384–322 BCE) was a student of Plato but developed his own ideas. Unlike Plato, he believed that Forms cannot exist separately from physical things. Instead, he argued that form and matter are always connected. This debate became important in the discussion of universals in philosophy.
Aristotle made contributions to many fields, including:
 Metaphysics – He created a system to classify different kinds of existence.
 Ethics – He believed that to live a good life, people must develop virtues and achieve eudaimonia (human flourishing).
 Logic – He created rules for correct reasoning, which influenced philosophy for centuries.
 Teleology – He said that everything in nature has a purpose or goal.
 Aristotle’s works became the foundation for many areas of Western philosophy and science. His ideas continued to be studied for centuries.
 Hellenistic and Roman 
After Aristotle, new schools of philosophy appeared, including Epicureanism, Stoicism, and Skepticism. These are called the Hellenistic schools of thought. They focused on topics like ethics, physics, logic, and epistemology (the study of knowledge). This period began after the death of Alexander the Great in 323 BCE and remained important until the end of the Roman Republic in 31 BCE.
The Epicureans followed the ideas of Democritus, believing that everything is made of tiny, indivisible atoms. They taught that pleasure is the highest good but did not support luxury or indulgence. Instead, they believed that true happiness comes from a simple and peaceful life, free from fear and pain.
The Stoics disagreed with the Epicureans. They thought that desires and fears prevent people from living a good life. Instead of chasing pleasure, they focused on reason, self-control, and virtue. They taught that people should accept whatever happens with calmness and wisdom.
The skeptics studied how people's opinions affect their happiness. They believed that strong opinions cause stress and that people should avoid making firm judgments about things they cannot be certain about. Some skeptics went further and said that nothing can ever be truly known.
In the 3rd century CE, a new school called Neoplatonism emerged, based on the ideas of Plato and Aristotle. The main idea of Neoplatonism was that everything comes from a single, mysterious source called "the One" or "the Good."
 Plotinus (204–270 CE) was the most famous Neoplatonist. He said that from the One, the intellect is created, which then creates the soul, which in turn creates the material world.
 Porphyry (234–305 CE) was his student and helped spread Neoplatonism.
Neoplatonism became an important influence on Christian, Jewish, and Islamic philosophy in later centuries.
 Medieval 
The medieval period in Western philosophy started around 400 to 500 CE and ended between 1400 and 1500 CE. One important difference between this time and earlier periods was the focus on religious ideas. The Christian Emperor Justinian ordered the closing of philosophy schools, like Plato's Academy, which led to philosophy being mainly studied within the Church. During this time, it became dangerous to challenge the Church's teachings. Because of this, some scholars think this period was a "dark age" compared to earlier and later times. Some of the big questions discussed during this period were about universals (how general ideas relate to real things), the nature of God, how to prove God's existence, and how reason and faith relate. Early medieval thinkers were influenced by Plato, while later thinkers followed Aristotle.
One important figure from this period was Augustine of Hippo (354–430 CE). He was greatly influenced by Platonism and used its ideas to understand Christian teachings. Augustine believed that God is both good and impossible to fully understand. He tried to explain how evil could exist in a world created by an all-good and all-powerful God. Augustine's answer was that humans have free will, meaning they can choose to do good or evil, and are responsible for those choices. He also made important contributions to other topics, like proving God's existence, his theory of time, and his ideas about just war.
Another important thinker was Boethius (477–524 CE), who was interested in Greek philosophy. He translated many works of Aristotle and tried to combine them with Christian teachings. Boethius worked on the problem of universals (ideas that apply to many things, like "redness" for all red things) and tried to find a way to explain Plato's and Aristotle's views together. He suggested that universals exist in people's minds but also in real objects. This idea later influenced other thinkers, especially those who argued that universals only exist in the mind. Boethius also thought about the Trinity, the Christian belief that God is three persons: the Father, the Son, and the Holy Spirit.
 Scholasticism 
In the later part of the medieval period, scholasticism became the main method of philosophy. Scholasticism was influenced by Aristotle's philosophy and focused on careful, systematic thinking. This period saw a renewed interest in Aristotle, especially because the Arabic–Persian tradition preserved, translated, and explained many of Aristotle's works that had been lost in the Western world.
Anselm of Canterbury (1033–1109 CE) is often called the father of scholasticism. He believed that reason and faith work together and depend on each other to fully understand the world. Anselm is best known for his ontological argument for the existence of God. He argued that God must exist outside of the mind because the greatest possible being must exist in reality, not just as an idea.
Peter Abelard (1079–1142 CE) also emphasized the harmony between reason and faith. He believed both come from the same divine source, so they cannot contradict each other. Abelard is also known for nominalism, the idea that universals (general concepts like "goodness") exist only in the mind, not as real things.
Thomas Aquinas (1224–1274 CE) is considered one of the most important philosophers of the medieval period. He built a complete system of scholastic philosophy based on Aristotle's ideas, covering topics like metaphysics (the nature of being), theology (the study of God), ethics, and politics. Aquinas's main work, Summa Theologiae, shows how faith and reason can work together. He argued that reason can support Christian teachings, but faith is needed because reason alone can't understand everything, especially about God. In metaphysics, Aquinas said everything has two parts: essence (what something is) and existence (whether it is real). He believed God's essence and existence are the same, which makes God unique. In ethics, Aquinas thought people are naturally inclined to do what is good because humans are rational.
Duns Scotus (1266–1308 CE) disagreed with some of Aquinas's ideas. For example, he rejected the idea that essence and existence are separate in things. Instead, Scotus argued that they are always connected in a thing. He also introduced the idea of haecceity, which means that each thing has a unique essence that makes it different from other things.
William of Ockham (1285–1347 CE) was one of the last important scholastic philosophers. He is known for Ockham's Razor, a principle that says the simplest explanation, with the fewest assumptions, is usually the best one. Ockham used this idea to argue for nominalism and against realism about universals, saying that universals are just names we use in our minds, not real things that exist on their own.
 Renaissance 
The Renaissance was a time of cultural and intellectual change that started in the middle of the 14th century and lasted until the early 17th century. It began in Italy and slowly spread to other parts of Western Europe. This period was marked by a renewed interest in the ideas of Ancient Greece, especially in philosophy. One of the main features of the Renaissance was humanism, a way of thinking that focused on humans and their potential. There was also a new focus on science and observation. This was very different from the Middle Ages, which were more centered on religion and Church teachings. During the Renaissance, thinking and learning were no longer mainly controlled by the Church. Many scholars were no longer church leaders.
One important part of this return to Greek philosophy was a new interest in Plato's teachings. This way of thinking, known as Renaissance Platonism, was still tied to Christian beliefs. Many thinkers tried to show how Plato's ideas could fit with Christianity. For example, the philosopher Marsilio Ficino (1433–1499) believed that souls connect the world of perfect forms (ideas) and the physical world we see. Plato said that love helps us rise to higher levels of understanding. Ficino thought this meant that loving knowledge can help bring people closer to God.
The interest in Greek philosophy was not only about Plato. Other Greek ideas, like Skepticism, Epicureanism, and Stoicism, also became popular again. These ideas were linked to Renaissance humanism, which focused on studying human life and culture. Humanism saw people as real individuals and helped create social and cultural changes that influenced philosophy. It also led to more interest in political thought.
For example, Niccolò Machiavelli (1469–1527) believed that rulers should focus on keeping their countries safe and stable. He said leaders might sometimes need to use force or be ruthless to protect their states. On the other hand, Thomas More (1478–1535) imagined a perfect society where people shared everything equally and worked for the common good.
The Renaissance also brought changes in how people thought about nature and science. These ideas helped prepare the way for the Scientific Revolution. One major change was a focus on using observation to study the world. Another was the belief that math could help explain what was observed.
Francis Bacon (1561–1626) is seen as someone who helped move from Renaissance thinking to modern science. He wanted to change the way people did science by replacing old methods with new ones. In his book Novum Organum, he supported the use of inductive reasoning—learning general truths by studying many examples. 
Another key figure was Galileo Galilei (1564–1642), who played an important role in changing our view of the universe. He supported the idea that the Sun, not the Earth, is at the center of the solar system.
 Early modern philosophy 
Early modern philosophy happened during the 1600s and 1700s. Philosophers from this time are usually grouped into two types: empiricists and rationalists. But today, many historians say the difference between them isn’t so clear—it's more about how much they leaned toward one idea or the other.
Both groups wanted to find a clear and careful way to study and understand the world. This focus on method was similar to what scientists were doing at the same time during the scientific revolution.
Empiricists believed that knowledge comes mainly from what we experience through our senses—like seeing, hearing, or touching. Rationalists, on the other hand, believed that reason and thinking are the main sources of knowledge. They also thought that some knowledge is innate, or inborn.
Even though the idea of using methods to understand the world started during the Renaissance, it became much more important in the early modern period.
In the second half of this time, the Enlightenment began. Enlightenment thinkers used new ideas from philosophy to question old traditions and authorities. They supported progress, freedom for individuals, and human rights.
 Empiricism 
Empiricism was a way of thinking that became popular in Britain during the early modern period. It is the idea that all knowledge comes from experience, especially from what we learn through our senses (like seeing, hearing, or touching).
John Locke (1632–1704) is often called the father of empiricism. In his book An Essay Concerning Human Understanding, he said that people are born with a blank mind, like a clean slate. He believed we gain all our ideas by experiencing the world around us. Locke also said that some qualities of objects (like size and shape) are always there, no matter who looks at them. He called these primary qualities. Other qualities (like color or taste) depend on the person experiencing them—these are secondary qualities.
George Berkeley (1685–1753) agreed with many of Locke’s ideas but took them further. He believed that things only exist if someone is thinking about them or seeing them. In other words, if no one sees or thinks about an object, it doesn’t really exist. This idea is called idealism.
David Hume (1711–1776) also believed that knowledge comes from experience. But he questioned how we know that one thing causes another. For example, just because we always see lightning before thunder doesn’t mean lightning causes thunder. Hume said we don’t actually see cause and effect—we just get used to certain things happening together and expect the same to happen again.
The ideas of Locke, Berkeley, Hume, and other empiricists helped shape the scientific method, especially the importance of observing, testing, and experimenting to learn about the world.
 Rationalism 
Rationalism was another major way of thinking during the early modern period. It is the belief that reason and thinking are the main sources of knowledge, rather than experience from the senses.
René Descartes (1596–1650) was an important figure in rationalism. He wanted to find knowledge that was 100% certain. To do this, he used doubt—he questioned everything he believed until he found something he could not doubt. That was the idea: "I think, therefore I am." He then built his system of philosophy using logic and reasoning. Descartes also believed in substance dualism, which means he thought the mind and the body are two different things that both exist but are separate.
Baruch Spinoza (1632–1677) was another rationalist who took reasoning even further. He used a method similar to geometry, starting with a few clear and simple truths and using step-by-step reasoning to build his ideas. Unlike Descartes, Spinoza believed that everything is made of one single substance, not two. This idea is called monism.
Gottfried Wilhelm Leibniz (1646–1716) was also an important rationalist. He believed in the principle of sufficient reason, which says that everything must have a reason or explanation. He used this idea to create a system of thought called monadology, where he said that the universe is made up of simple, indivisible things called monads.
 Enlightenment and late modern philosophy 
In the second half of the modern period, a movement called the Enlightenment began. This was a time when people used ideas from both empiricism (learning from experience) and rationalism (learning through reason) to question old traditions and authority. Enlightenment thinkers believed in individual freedom, knowledge, and the idea that society can improve through progress.
One of the most important Enlightenment thinkers was Immanuel Kant (1724–1804). He believed that reason was key to understanding the world. He didn’t accept beliefs that were followed blindly. Kant tried to combine ideas from both empiricism and rationalism into one system. He said that our minds shape how we see reality using built-in ways of understanding. In ethics (moral philosophy), he created a system called deontology, which says people should follow universal rules of right and wrong, no matter the situation. This idea is called the categorical imperative.
Other well-known Enlightenment thinkers were Voltaire, Montesquieu, and Jean-Jacques Rousseau.
During this time, political ideas also changed. Thomas Hobbes (1588–1679) wrote a famous book called Leviathan. He believed that, without laws or government, people would fight each other and live in fear. To avoid this, people agree to a social contract, giving up some freedom in exchange for peace and safety from a powerful government.
Jean-Jacques Rousseau also believed in the idea of a social contract, but he had a more hopeful view of human nature. He thought people were naturally good and should be free to make their own laws. Because of this, he supported democracy.
 19th century philosophy 
The 19th century was a time of many different ideas in philosophy. During this period, the word "philosophy" started to mean something different from science and math. Philosophers often followed two main paths:
Some wanted to build big, complete systems that explained everything (like German and British idealists).
Others focused on specific topics like ethics (right and wrong) and how we know things (knowledge). These included thinkers like Bentham, Mill, and the American pragmatists.
 German Idealism 
One major group was called German idealists. This tradition began with Immanuel Kant, who said that our minds help shape what we experience. Later philosophers thought Kant's ideas had problems, so they tried to improve them.
 Johann Gottlieb Fichte believed that the self (or ego) creates both itself and the world around it.
 Friedrich Wilhelm Joseph Schelling said everything came from a more basic force he called the absolute or world-soul.
Georg Wilhelm Friedrich Hegel is considered the most important German idealist. He believed that freedom was the goal of history and that true knowledge comes when we understand that mind and world are really one. He called this deep truth "the absolute." He thought art, religion, and philosophy all help us reach this understanding.
 Other movements 
Historicism, started by thinkers like Herder, focused on the importance of history and unique events, not just timeless truths.
Neo-Kantianism tried to bring back and update Kant’s ideas.
British idealism (like Francis Herbert Bradley) was influenced by Hegel and believed that reality is a single whole. Bradley also thought that external relationships don’t really exist on their own.
 Marx and materialism 
Karl Marx was inspired by Hegel but disagreed with his focus on ideas. Instead, Marx believed that economic forces drive history, not spirit or mind. His theory is called dialectical materialism, and it became very influential in places like Russia and China.
 Schopenhauer and Nietzsche 
Arthur Schopenhauer believed that everything in the world comes from a powerful, blind force called the will. He thought life was mostly about suffering and had a dark view of the world.
Friedrich Nietzsche, who was influenced by Schopenhauer, had a different idea: he believed in the will to power—the idea that living things are always trying to grow, improve, and gain strength. Nietzsche criticized religion and traditional morals, saying they were just ways people tried to control others.
 Ethics and utilitarianism 
In ethics, Jeremy Bentham created utilitarianism. He said the best action is the one that brings the most happiness and the least pain—this is known as “the greatest good for the greatest number.”
His student, John Stuart Mill, agreed but added that the quality of happiness matters too, not just the amount.
 Pragmatism in America 
Near the end of the 1800s, a new kind of philosophy called pragmatism started in the United States. Pragmatists believed that ideas should be judged by how useful they are in real life.
Charles Sanders Peirce said the meaning of an idea comes from what it does or how it works in practice.
William James, a friend of Peirce, used these ideas in psychology. He said that thoughts and experiences are not separate moments but flow like a stream of consciousness.
 20th century philosophy 
In the 20th century, philosophy mostly developed in two main traditions:
 Analytic philosophy – This was popular in English-speaking countries like the United States and the UK. It focused on using clear language and careful thinking to solve traditional problems in areas like:
 What exists (metaphysics)
 What we know (epistemology)
 Science and ethics: Philosophers in this group often used logic and studied the meaning of language.
 Continental philosophy – This was more common in Europe, especially in Germany and France. This type of philosophy included many different styles and ideas, such as:
 Phenomenology (the study of experience)
 Hermeneutics (the study of understanding texts)
 Existentialism (focused on personal freedom and meaning)
 Deconstruction (examining how language creates meaning)
 Critical theory and psychoanalysis (studying society and the mind)
These two traditions were different in style and focus, but both were important.
 Growth of philosophy 
Philosophy became much more popular in the 20th century. Many more books and papers were written, and more people became philosophers, especially in universities.
Also, more women began to study and write philosophy. Still, men continued to be the majority in the field.
 Feminist philosophy 
A major new development was the rise of feminist philosophy, which looks at how traditional ideas and systems often treat women unfairly. Important feminist philosophers include:
 Simone de Beauvoir – A key thinker who helped start feminist philosophy.
 Martha Nussbaum
 Judith Butler
 Other philosophies 
Some philosophers didn’t fit into either the analytic or continental groups. One example is pragmatism, which started in the 19th century but grew in new ways during the 20th century.
Philosophers like Richard Rorty and Hilary Putnam used pragmatism to talk about:
 Knowledge
 Politics
 Education
 Social sciences
 Analytic philosophy 
Analytic philosophy became popular in English-speaking countries in the 20th century. It focuses on clear thinking and logical analysis, especially using language carefully to solve problems in areas like knowledge, ethics, and science.
George Edward Moore (1873–1958) helped start analytic philosophy. He believed in common sense and argued against extreme doubts about reality. In ethics, he said we should try to do what is good. He believed the word "good" can’t be explained using other words and that we can know what is good through intuition (a kind of direct knowing).
Gottlob Frege (1848–1925) was also an early analytic philosopher. He created modern symbolic logic (a way of writing and analyzing logical statements). He tried to show that math is based on logic (called logicism). His work influenced many philosophers, even beyond logic.
Bertrand Russell (1872–1970) built on Frege’s ideas and tried to include more parts of math, like geometry, in logicism. He also worked on the philosophy of language. One of his famous ideas was how to understand strange sentences like “the present King of France,” which refers to something that doesn’t exist. He created the theory of logical atomism, which says the world is made of simple, basic facts.
Wittgenstein (1889–1951) was Russell’s student. In his first book, he said the world and language share the same logical structure, and language shows the facts of the world. Later, he changed his view. He said language is like a set of different games, and the meaning of words comes from how we use them in real life.
 Logical positivism 
This group of thinkers believed that only things we can see, hear, or test scientifically are meaningful. They were called the Vienna Circle, and one key thinker was Rudolf Carnap (1891–1970). They rejected metaphysics (questions about things beyond experience) because they said such questions couldn’t be proven. Willard Van Orman Quine (1908–2000), Carnap’s student, disagreed with this. He said science is the best way to understand the world and even math is real because we need it for science.
 Later analytic philosophy 
Wittgenstein’s later ideas led to ordinary language philosophy, which studies everyday language to solve philosophical problems.
John Langshaw Austin (1911–1960) introduced the idea of speech acts—how saying something can also be doing something (like making a promise).
Other important thinkers in this area were Gilbert Ryle and Peter Strawson.
The focus on language was called the linguistic turn.
 Ethics and politics 
In ethics, Richard Hare and John Mackie made big contributions.
In political philosophy, John Rawls and Robert Nozick had major influence. 
 Continental philosophy 
Continental philosophy is a group of different ways of thinking about big questions, especially in Europe. It includes ideas like phenomenology, existentialism, hermeneutics, critical theory, and postmodernism. These approaches often focus on human experience, society, and interpretation rather than strict logic.
 Phenomenology 
Phenomenology is about describing human experience exactly as it happens, without bringing in outside opinions or beliefs.
Edmund Husserl (1859–1938) started this idea. He believed that to truly understand experience, we must put aside all our assumptions and look at what we directly feel and think.
His student Martin Heidegger (1889–1976) took these ideas further. He said we always already have a basic understanding of the world, and we need to interpret our experiences to truly understand them.
Hans-Georg Gadamer (1900–2002) added to this by saying that our understanding changes over time through dialogue and interpretation. He called this the fusion of horizons, where our current ideas mix with new ones we learn about.
 Existentialism 
Heidegger also talked about how we care about the world, and how we feel things like anxiety when we think deeply about life.
This inspired Jean-Paul Sartre (1905–1980), who created existentialism.
Existentialists say that humans are free and must take responsibility for their actions.
They also believe that life has no fixed meaning, and this freedom can make people feel anxious.
Albert Camus (1913–1960), another thinker, said that life seems absurd because it has no clear purpose, but we still keep trying to find meaning.
 Critical Theory 
Critical Theory was created by a group of thinkers in Germany known as the Frankfurt School.
They didn’t just want to study society—they wanted to change it.
They looked at power, inequality, and injustice, and how some people are oppressed.
Important thinkers in this group include Theodor Adorno, Max Horkheimer, and Herbert Marcuse.
 Postmodernism 
In the second half of the 20th century, many philosophers began to question old ideas like absolute truth, objectivity, and progress.
This way of thinking is often called postmodernism.
Michel Foucault (1926–1984) said that knowledge is connected to power, and those in power shape what people think is true.
Jacques Derrida (1930–2004) created deconstruction, a method that finds hidden contradictions in texts by breaking apart their basic ideas (like “presence vs. absence”).
Gilles Deleuze (1925–1995) used ideas from psychology to rethink concepts like desire, identity, and knowledge.


Crime in India: Crime in India is very common and happens in many different ways. Along with violent crimes (like homicide, robbery, and assault), and property crimes (like burglary, theft, motor vehicle theft, and arson), there are major problems with organized crime, the illegal drug trade, arms trafficking, corruption, and many other forms of crime. The most common types of crimes in India are listed below.
 Organized crime 
Organized crime is planned and done by groups of people. Their goals are to gain power and make money in Illegal ways. Common organized crimes in India include:
 Drug trafficking (moving and selling illegal drugs)
 Gunrunning (getting illegal guns, sneaking them into the country, and selling them)
 Money laundering
 Extortion (telling a person that he has to pay money, or something bad will happen to him, his business, or his family)
 Murder for hire (killing someone for pay)
 Fraud
 Human trafficking (tricking or kidnapping people, usually children or young women, into becoming slaves)
 Poaching (killing plants or animals that are illegal to kill, then selling them)
Many criminal organizations also commit these crimes:
 Black marketing (trading or selling things on the black market, which is illegal)
 Political violence (for example, trying to hurt or scare political candidates who they dislike)
 Religious violence (hurting or scaring other people because they are a different religion)
 Terrorism, including the 1993 Bombay bombings, 2006 Mumbai train bombings and the 2008 Mumbai attacks
 Abduction (kidnapping)
Illegal drug trade
India is located between the Golden Crescent (made of Pakistan, Afghanistan, and Iran) and the Golden Triangle (made of Myanmar, Thailand, and Laos). The Golden Crescent and the Golden Triangle are the two biggest makers of opium in Asia. Their opium-making is secret and illegal. Because of India's location, a lot of this illegal opium is trafficked (snuck illegally) through India's borders.
India is the world's largest maker of legal opium. But its opium gets diverted (taken away by drug traffickers) to other countries where opium and heroin are illegal.
India is a common starting point for drug traffickers who take heroin on ships from Afghanistan and Pakistan, and from Myanmar, Laos, and Thailand. The heroin is then smuggled from Pakistan and Myanmar, with some heroin also shipped through Nepal. Most heroin shipped from India goes to Europe. There have been reports of heroin smuggled from Mumbai to Nigeria to get the drugs to more countries.
In Maharashtra, Mumbai is an important centre where people sell heroin. The most commonly used drug in Mumbai is "Indian heroin" (called desi mal by the local population). Both public transportation (road and rail transportation) and private transportation are used for this drug trade.
The Government of India has tried a few ways of fighting drug trafficking in the country. India is a party to (meaning it signed onto and agreed to follow):
 The Single Convention on Narcotic Drugs (1961) (today, the word narcotic usually means "illegal drugs")
 The Convention on Psychotropic Substances (1971) ("psychotropic substances" are drugs that change the way the brain works; this causes changes in how a person feels, what they think is real, and how conscious they are)
 The Protocol Amending the Single Convention on Narcotic Drugs (1972) (a change or update to the original Single Convention on Narcotic Drugs)
 The United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances (1988) (a treaty, or agreement, among most of the countries in the United Nations, and some other countries; its goal was to help enforce the Single Convention on Narcotic Drugs and the Convention on Psychotropic Substances)
Arms trafficking
According to a report published together by Oxfam, Amnesty International, and the International Action Network on Small Arms in 2006, there are around 40 million illegal small arms in India. This would mean that India had over half of the small arms in the entire world (the world had 75 million, according to the report).
Most of the illegal small arms end up in the states of Bihar, Chhattisgarh, Uttar Pradesh, Jharkhand, Orissa and Madhya Pradesh. In India, a used AK-47 costs $3,800 on the illegal black market. But a large amount of illegal small arms are made in illegal arms factories in Uttar Pradesh and Bihar, and sold on the black market for as little as $5.08.
Chinese pistols are in demand in the illegal small arms market in India because they are easy to get and cheaper. This creates a major problem for the states of Bihar, Uttar Pradesh, Jharkhand, Chhattisgarh, Orissa, Maharashtra, West Bengal, Karnataka and Andhra Pradesh. These states are affected by Naxalism. Naxalites are groups of Communist guerrilla fighters in India. Many Chinese pistols, AK-47s, and M-16 rifles are smuggled into India through the border between India and Nepal. These weapons are then used by the Naxalites, who have ties to Maoists in Nepal.
Poaching and wildlife trafficking
Illegal wildlife trade in India has increased. There are laws against killing some animals, taking rare plants, and smuggling them into other countries. But a report published by the Environmental Investigation Agency in 2004 said that more traders of wildlife skins go to India than any other country. Between 1994 and 2003, there were 784 cases where the skins of tigers, leopards, or otters have been seized (taken away from illegal traders by police). Also between 1994 and 2003, police seized 698 otters who had been poached (illegally taken or killed).
Poaching of elephants is a big problem in Southern India and in the North-Eastern states of Nagaland and Mizoram. Most tiger poaching happens in Madhya Pradesh, Uttar Pradesh, Uttarakhand, Orissa, West Bengal, Assam and Arunachal Pradesh.
Once they are poached, leopards, rhinoceros, reptiles, birds, insects, and rare species of plants are smuggled into the countries in Southeast Asia and the People's Republic of China. Often, poachers bring illegal animal skins from India to Kathmandu, the capital city of Nepal, ion the way to Tibet and China. In its report in 2004, the Environmental Investigation Agency said that there was not enough cooperation between India, Nepal, and the People's Republic of China. Because these countries were not cooperating, they could not work together to enforce anti-poaching laws and were not interested enough in fighting wildlife crime together.
On April 1, 1973, Prime Minister Indira Gandhi launched Project Tiger, which was first started in 1972. Project Tiger was a wildlife conservation project - a project that tried to protect wildlife from being poached. Project Tiger created 23 tiger reserves (protected areas for tigers), said they had been successful since the number of tigers in India had increased. But critics like conservationist Billy Arjan Singh said that tigers had only moved to India from Nepal because their habitat in Nepal had been destroyed - not because of wildlife policy in India.
Cyber crime
Cyber crime - crimes done by computer - are very, very common in India. Examples of cyber crime include: 
 Computer hacking (where a person breaks into a computer using another computer, and steals information)
 Cyber stalking (following someone all the time, using a computer, to make them feel scared)
 E-mail fraud (for example, emailing people asking to send money in scams)
 Spam (where "spammers" get email addresses for thousands of people and send them all unwanted ads)
India has tried many things to decrease cybercrime. The Information Technology Act 2000 was passed by the Parliament of India in May 2000. Its goal was to decrease cyber crimes and start setting up laws to allow e-commerce. However, Pavan Duggan, a lawyer with the Supreme Court of India and cyber law expert, complained that the IT act focused too much on promoting e-commerce and not enough on dealing with cybercrimes. Cybercrime cells have been set up in major cities. But Duggal said the problem is that most cases are never reported because people do not know their rights under Indian law.
In 2001, India and United States joined together in an Indian-US cyber security forum as part of a counter-terrorism dialogue. In 2006, India and the US agreed to have their law enforcement agencies work together more in fighting cybercrimes. They saw this as an important part of counter-terrorism efforts.
In 2006, U.S. President George W. Bush and Indian Prime Minister Manmohan Singh met to discuss cyber security. Afterward, they held a press conference together. They said that because cyber security and cyber forensic research (like finding evidence in computers) are so important, India and the United States were also talking about a draft protocol on cyber security.
Corruption and police misconduct
Corruption is very common in India. It is common in every section and every level of Indian society. Corruption has also become a big part of Indian politics. In India, corruption takes many forms, including:
Bribes (for example, giving money to a government worker to get them to do something illegal)
 Tax evasion (not paying taxes)
 Not obeying exchange controls (rules made by the government about whether people can buy or sell currencies (money) from other countries)
 embezzlement (stealing or misusing money that belongs to a company or government)
India has state laws that make it illegal for police to torture people. But these laws are not often obeyed. Torture is often used when people are arrested or jailed by the police. This torture is a major cause of deaths in police custody. The police often torture innocent people until they 'confess' (they say they did the crime). This false confession is then used to save important, rich people who have actually committed crimes. One major problem that keeps police violence possible is a lack of accountability (meaning no one gets in trouble if they torture a person), according to G.P. Joshi. Joshi runs the Indian branch of the Commonwealth Human Rights Initiative in New Delhi.
In 2006, the Supreme Court of India decided a case called Prakash Singh vs. Union of India. In its decision, the Court ordered central and state governments to begin police reform. The Court had two goals with its decision. The first was to give tenure to police officers, and to make it simpler for police officers to get hired or transfer to a different area. The second was to increase police accountability.
Criminals visit markets and other places that are popular with tourists, with the goal of committing crimes against foreigners (people from other countries). Westerners have become victims of robbery, rape, and other violent attacks. Because foreigners often have more money than most people in India, they are often criminals' favorite target for robbery and other serious crimes. In April 1999, a group of Indians made friends with Swaraj Damree, a tourist from Mauritius. The group kidnapped Damree and held him captive for 25 days. They robbed him of cash worth $1,500 in U.S. dollars, and stole his traveller's cheques, wrist watch, gold chain, bracelet, two bags and suitcase. In 2000, two German tourists were shot in Himachal Pradesh. A few weeks later, two Spanish tourists were killed by robbers in the same state. Many foreign tourists are victims of violent crime in Kolkata. In September 2006, criminals robbed the wallet of a British woman in Kolkata. The same month, a Japanese tourist was robbed on his way to Sudder Street. In October 2006, a foreigner was robbed during the day on Park Street.
Petty crime
Petty crime, like stealing people's wallets and bags, is common in India. Stealing valuable things from foreigners' luggage on trains and buses is also common. People traveling alone are especially likely to have their things stolen by pickpockets and purse snatchers, who usually work in crowded areas.
Passport theft
In India, stealing tourists' passports from their luggage on trains and buses is very common. Theft of U.S. passports happens often, especially in major tourist areas.
Scams
Criminals run many scams against tourists, especially in Jaipur, the capital of Rajasthan. The criminals usually pick younger tourists to try to scam. They tell the tourists that they can make a lot of money if they move gems or gold, or if they take expensive carpets back home in their luggage to avoid customs duties.
If a tourist agrees, the scam continues for a few days. Then a new scam artist offers to show the tourist interesting places in the area. The scammers also offer cheap places to stay and meals to the tourist. They do this so that the tourist ends up being with the scam artist all the time. The scam artist is then threatened and maybe hurt, until he gives up his passport to the scammers.
In 2006, an American became a victim of a scam at Chhatrapati Shivaji International Airport in Mumbai. She lost $77 U.S. dollars.
Taxi scam
Taxi drivers also run scams in India. These scams are run on tourists who do not know their way around India or Indian airports. Some taxi drivers will drive tourists around the whole airport, so they can charge a lot of money for the ride when the part of the airport that the tourist wants to go to was actually very close by. In a report, the Overseas Security Advisory Council talked about taxi scams and how to avoid them.
Rape of foreigners
There have been more and more rapes of tourists at popular tourist spots. In March 2006, Biti Mohanty, the son of a senior police official in Orissa, raped a German tourist in Alwar, Rajasthan. The next month, a Japanese woman was raped in Pushkar, Rajasthan. In June 2007, a South Korean tourist was raped near Manali. In September 2007, two Japanese women were gang-raped in Agra, a popular tourist spot in India where the Taj Mahal is located.
The Indian state of Rajasthan is a popular place among foreign tourists. One out of every three tourists that go to India visit this state. Rajasthan has been rattled by rape cases of foreign tourists. The Indian Bureau of Consular Affairs has warned women from the United States not to travel alone in India.
Crime over time
A report published by the National Crime Records Bureau compared crime rates from 1953 to 2006. The report found that: 
 Burglary was less common in 2006 than in 1953. It was 38% less common in 2006 (having dropped from 1,47,379 known cases of burglary in 1953 to 91,666 in 2006).
 Robbery had increased by 120% (from 8,407 in 1953 to 18,456 in 2006).
 Riots had increased by 176% (from 20,529 in 1953 to 56,641 in 2006).
 Murder had seriously increased, by 231% (from 9,803 in 1953 to 32,481 in 2006).
 Kidnapping had increased the most, by 356% (from 5,261 to 23,991)
In 2006, 51,02,460 cognizable crimes were committed. In India, cognizable crimes are serious crimes, where a police officer could make an arrest without needing a warrant first. Examples of cognizable crimes include rape, murder, and theft. Among the cognizable crimes committed in 2006, there were 18,78,293 Indian Penal Code (IPC) crimes and 32,24,167 Special & Local Laws (SLL) crimes. The IPC crime rate in 2006 was 167.7 compared to 165.3 in 2005, showing an increase of 1.5% in 2006 over 2005. SLL crime rate in 2006 was 287.9 compared to 290.5 in 2005, showing a decrease of 0.9% in 2006 over 2005.
SOURCE: National Crime Records Bureau
Crime by area
Different places in India have different amounts and types of crime. For example:
 In 2006, the highest crime rate was reported in the city of Pondicherry (447.7%) for crimes under Indian Penal Code. This is 2.7 times the national crime rate of 167.7%. Among states in India, Kerala reported the highest crime rate at 312.5%.
 About 34% (one out of three) IPC crimes in India's very large cities happened in only three of those cities: Delhi (16.2%), Mumbai (9.5%), and Bangalore (8.1%). 
 Of the 35 very large cities in India, Indore reported the highest overall crime rate (769.1%). The second- and third-highest crime rates were from Bhopal (719.5%) and Jaipur (597.1%). 
 Some cities had higher rates of violent crime than the whole country of India. India's national violent crime rate was 18.4%. Jammu and Kashmir's violent crime rate was 33.7%; Manipur's was 33.0%; Assam's was 30.4%; and both Daman and Diu's and Pondicherry's were 29.4% 
 Uttar Pradesh reported the highest rate of violent crimes. Violent crimes in Uttar Pradesh made up 12.1% of the total violent crimes in all of India (24,851 out of 2,05,656). Violent crimes in Bihar made up 11.8% of violent crimes in India. (24,271 out of 2,05,6556). 
 Among India's 35 very big cities, rapes in Delhi made up 31.2% of total rape cases in the 35 cities (533 out of 1,706). Madhya Pradesh has reported the highest number of rape cases (2,900), making up 15.0% of the rape cases reported in all of India. 
 Uttar Pradesh reported 16.9% (5,480 out of 32,481) of India's murder cases, and 18.4% (4,997 out of 27,230) of the country's attempted murder cases.


History of the creation–evolution controversy: The creation–evolution controversy has a long history. Scientists had some ideas how evolution works. Because these theories contradict the creation myth in the Book of Genesis, religious people and organizations questioned these ideas. For a long time, only the priests could read the Bible, which was written in Latin or in Greek. It was only the priests who interpreted the texts in the Bible. The priests often said that the Book of Genesis should not be read literally and taught it as an allegory. With the advent of the printing press, the Bible was translated into other languages. More people were able to read and write, and more literal understandings of scripture flourished. This allowed some religious persons and groups to challenge scientists who supported evolution, such as biologists Thomas Henry Huxley and Ernst Haeckel.
 Creation–evolution controversy in the age of Darwin 
 The first people to speak about evolution were Empedocles and other Greek philosophers in Europe (5th century BCE) andTaoism in Asia. The history of evolutionary thought in Christian theology dates back to Augustine of Hippo (4th century) and Thomas Aquinas (13th century). The modern creation–evolution controversy started in Europe and North America in the late 18th century. Discoveries in geology led to various theories of an ancient earth, and fossils showing past extinctions prompted early ideas of evolution. These ideas were particularly controversial in England, where both the natural world and the hierarchical social order were thought to be fixed by God's will. As the terrors of the French Revolution developed into the Napoleonic Wars, followed by economic depression threatening revolution in Great Britain itself, these ideas were rejected, associated only with radical agitators.
When the economy recovered, things improved. When the book Vestiges of the Natural History of Creation was anonymously published in 1844 its ideas of transmutation of species attracted wide public interest. The work was attacked by the scientific establishment and many theologians who believed it to be in conflict with their interpretations of the biblical account of life's, especially humanity's, origin and development. However, radical Quakers, Unitarians and Baptists welcomed the book's ideas of "natural law" as supporting their struggle to overthrow the privileges of the Church of England.
Vestiges of the Natural History of Creation remained a best-seller- It paved the way for widespread interest in the theory of natural selection. English naturalist Charles Darwin introduced this ideas in his 1859 book, On the Origin of Species. Darwin's book was praised by Unitarians as well as by liberal Anglican theologians. The theologians' book Essays and Reviews (1860) was more controversial in Britain than Darwin's. It questioned the historical accuracy of literal interpretations of the Bible and said that miracles were irrational.
Darwin's book revolutionized the way naturalists viewed the world. The book and its promotion attracted attention and controversy, and many theologians reacted to Darwin's theories. For example, in his 1874 work What is Darwinism? the theologian Charles Hodge argued that Darwin's theories were like atheism. Thomas Henry Huxley, added to the controversy when he wrote that Christianity is a "...compound of some of the best and some of the worst elements of Paganism and Judaism. [influenced by] certain people of the Western world..." Perhaps the most uncompromising of the evolutionary philosophers was Ernst Haeckel, who dogmatically affirmed that nothing spiritual exists.
A fundamental change in the Protestant objections to evolution occurred after about 1875. Previously, citing Louis Agassiz and other scientific luminaries, Protestant contributors to religious quarterlies dismissed Darwin's theories as unscientific. After 1875, it became clear that the majority of naturalists were in favor of evolution, and a sizable minority of these Protestant contributors rejected Darwin's theory because it called into question the veracity of Scriptures. Even so, virtually none of these dissenters insisted on a young Earth.
The greatest concern for creationists in the late 19th century was the issue of human ancestry. In the words of an 1896 religious tract:
{{cquote|I do not wish to meddle with any man's family matters, or quarrel with any one about his relatives. If a man prefers to look for his kindred in the zoological gardens, it is no concern of mine; if he wants to believe that the founder of his family was an ape, a gorilla, a mud-turtle, or a monar, he may do so; but when he insists that I shall trace my lineage in that direction, I say No sir!...I prefer that my genealogical table shall end as it now does, with 'Cainan, which was the son of Seth, which was the son of Adam, which was the son of God,' rather than invent one which reads, 'Which was the son of skeptic, which was the son of monkey, which was the son of oyster, which was the son of monar, which was the son of mud!'''—a genealogical table which begins in the mud and ends in the gravel, which has a monar at the head, a monkey in the middle, and an infidel at the tail.}}
Creationists during this period were largely premillennialists; their belief in Christ's return depended on a quasi-literal reading of the Bible. However, they were not as concerned about geology, freely granting scientists any time they needed before the Edenic creation to account for scientific observations, such as fossils and geological findings. In the immediate post-Darwinian era, few scientists or clerics rejected the antiquity of the earth or the progressive nature of the fossil record. Likewise, few attached geological significance to the Biblical flood, unlike subsequent creationists. Evolutionary skeptics, creationist leaders and skeptical scientists were usually either willing to adopt a figurative reading of the first chapter of Genesis, or allowed that the six days of creation were not necessarily 24-hour days.
 Scopes Trial 
The reaction in the United States matched the developments in Britain, and when Alfred Russel Wallace went there for a lecture tour in 1886–1887 his explanations of "Darwinism" were welcomed without any problems, but attitudes changed after the First World War. The controversy became political when public schools began teaching that man evolved from earlier forms of life per Darwin's theory of natural selection. In response, the U.S. state of Tennessee passed the Butler Act of 1925 prohibiting the teaching of any theory of the origins of humans that contradicted the teachings of the Bible. This law was tested in the highly publicized Scopes Trial of 1925. The law was upheld by the Tennessee Supreme Court, and remained on the books until 1967 when it was repealed. In 1968, the U.S. Supreme Court ruled in Epperson v. Arkansas that banning the teaching of specific theories contravened the Establishment Clause of the First Amendment to the United States Constitution because their primary purpose was religious.
 ICR and the co-opting of the creationist label 
John C. Whitcomb and Henry M. Morris' influential The Genesis Flood: The Biblical Record and Its Scientific Implications was published in 1961. The authors argued that creation was literally six days long, that humans lived at the same time as dinosaurs, and that God created each kind of life. When it was published, Morris became a popular speaker, spreading anti-evolutionary ideas at fundamentalist churches, colleges, and conferences. Morris set up the Creation Science Research Center , an organization dominated by Baptists, as part of the Christian Heritage College. The CSRC rushed publication of biology text books that promoted creationism. These efforts were against the recommendations of Morris, who urged a more cautious and scientific approach. Ultimately, the CSRC broke up, and Morris founded the Institute for Creation Research in 1970. Morris promised that the ICR, unlike the CSRC, would be controlled and operated by scientists. During this time, Morris and others who supported flood geology, adopted the scientific sounding terms scientific creationism and creation science. The flood geologists effectively co-opted "the generic creationist label for their hyperliteralist views." Previously, creationism was a generic term describing a philosophical perspective that presupposes the existence of a supernatural creator.
 The Catholic Church and evolution 
Among the first recorded responses of a prominent Roman Catholic clergyman to Darwin's theory was that of the Blessed John Henry Newman, who in 1868, in a letter to a fellow priest, made the following comments:
Some point to the fact that before ordination all Catholic priests have to study the teachings of Thomas Aquinas, who subscribed to an Aristotelian view of evolution, in which he says that animal species evolve by means of mutations and natural law.
More recent statements have been made by Pope John Paul II and Pope Benedict XVI that also support a theistic understanding of evolution.
 The current controversy 
The controversy continues to this day. Creationist organizations actively attack the scientific consensus on the origins and evolution of life. Many religious groups want to promote other forms of creationism (usually young Earth creationism, creation science, old Earth creationism or intelligent design ) as an alternative. Most of these groups are explicitly Christian, and more than one sees the debate as part of the Christian mandate to evangelize.
Some see science and religion as views that are so different that they cannot be reconciled. Mainstream churches and some scientists consider science and religion to be separate categories of thought, which ask fundamentally different questions about reality and propose different ways of investigating it.
More recently, the intelligent design movement has taken an anti-evolution position which avoids any direct appeal to religion. Leonard Krishtalka, a paleontologist and an opponent of the movement, has called intelligent design "nothing more than creationism in a cheap tuxedo," and, in Kitzmiller v.Dover Area School District'' (2005) United States District Judge John E. Jones III ruled that "intelligent design is not science," but is "grounded in theology" and "cannot uncouple itself from its creationist, and thus religious, antecedents." Before the trial began, U.S. President George W. Bush commented endorsing the teaching of intelligent design alongside evolution "I felt like both sides ought to be properly taught ... so people can understand what the debate is about." Scientists argue that intelligent design does not represent any research program within the scientific community, and is opposed by most of the same groups who oppose creationism.


Tibetans in India: རྒྱ་གར་ནང་གི་བོད་མི།
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  Flag of Tibet.svg
  Flag of Tibet and the Tibetan people
  83,799
  Tibetic languages and Hindi
  Buddhism, minority Bon
  Sherpa, Bhotia, Lepcha, Tamang, Gurung, Ladakhi, Ngalop, Sharchop, and other Sino-Tibetan people
Tibetans in India are one of the biggest Tibetan communities living outside Tibet. After the 1959 uprising against Chinese rule, the 14th Dalai Lama and many Tibetans ran away to India for safety. Since then, India has been the main country giving them shelter and places to live. The Tibetan government-in-exile, called the Central Tibetan Administration, is based in Dharamshala, in the state of Himachal Pradesh.
 Background 
Tibetans and Indians have had close ties for a long time because of Buddhism. But the large movement of Tibetans to India started in 1959. That year, the 14th Dalai Lama and many Tibetans escaped from Tibet after China crushed a protest in Lhasa. India’s Prime Minister at the time, Jawaharlal Nehru, gave them safe shelter. He also let them set up the Tibetan Government-in-Exile in Dharamshala, a town in Himachal Pradesh.
Between 1959 and 1963, about 80,000 Tibetans came to live in India. The Indian government gave them land to live and work on in places like Himachal Pradesh, Karnataka, Arunachal Pradesh, and Uttarakhand. More Tibetans came later during the Cultural Revolution (1966–1976) and again in the 1980s and 1990s because life in Tibet was still very hard under Chinese rule.
 Settlements 
Tibetans in India primarily reside in over 35 designated settlements across various states. The largest Tibetan communities are found in:
 Dharamshala, Himachal Pradesh – Headquarters of the Tibetan Government-in-Exile and home to the Dalai Lama.
 Bylakuppe, Karnataka – One of the largest Tibetan settlements, home to several monasteries and institutions.
 Mundgod, Karnataka – A major settlement with monastic centers.
 Majnu-ka-tilla, Delhi – A well-known Tibetan refugee colony in India's capital.
The 2011 census of India recorded 83,799 Tibetans in India.
 Legal status 
Tibetans in India have a special legal status. They are not Indian citizens, but the Indian government gives them Identity Certificates, which they can use to travel. Before, it was hard for Tibetans to get Indian passports. But in 2017, a court said that Tibetans born in India between 1950 and 1987 can become Indian citizens under the law. Still, many Tibetans do not apply for citizenship because they would lose the special help they get as refugees.
 Culture and religion 
Tibetans in India have preserved their cultural and religious traditions. Tibetan Buddhism plays a central role in community life, with major monasteries such as Namdroling Monastery in Karnataka and Tawang Monastery in Arunachal Pradesh serving as cultural hubs. Institutions such as the Library of Tibetan Works and Archives in Dharamshala work to preserve Tibetan literature, history, and philosophy.
Losar (Tibetan New Year) and the Dalai Lama’s birthday are widely celebrated in Tibetan settlements. Traditional Tibetan arts, including Thangka painting and opera, are also maintained through community efforts and educational programs.
 Language 
The Tibetic languages are a group of related languages from the Sino-Tibetan family. They are spoken by about 8 million people, mostly Tibetans, in places like the Tibetan Plateau, Baltistan, Ladakh, Nepal, Sikkim, and Bhutan. These languages are very different from each other and cannot be easily understood across regions. Classical Tibetan is an important written language, especially for Buddhist texts. Some main forms of Tibetan—like Central Tibetan (spoken in Lhasa), Khams, and Amdo—are seen as dialects of one language because they share the same writing system. Other related languages, like Dzongkha, Sikkimese, Sherpa, Jirel, and Ladakhi, are treated as separate languages.
 Economy and education 
Many Tibetans in India are engaged in handicrafts, agriculture, and small businesses. The Carpet weaving industry, in particular, is a significant source of income for Tibetan refugees. Others operate restaurants, hotels, and travel businesses catering to tourists interested in Tibetan culture.
Education is very important for the Tibetan exile community. In 1961, the Central Tibetan School Administration was created to run schools for Tibetan children. For college-level education, there are places like the Dalai Lama Institute for Higher Education and Sarah College for Higher Tibetan Studies.


World War II: June 2025
World War II, or the Second World War, was a global conflict involving all continents of the world, except Antarctica. It involved fighting in most of the world from 1939 to 1945. Some fighting started in 1937, when Imperial Japanese forces started the Second Sino-Japanese War. Most of the world's countries, including all of the great powers, fought as part of two military alliances: the Allied Powers and the Axis Powers.
The war involved more countries, cost more money, involved more people, and killed more people than any other war; 73 million people died, most of whom were civilians. The war included massacres, a genocide called the Holocaust, strategic bombing, starvation, and disease. This was the only time a nuclear weapon was used in war. 
The two sides were the Allies (at first China, France and the United Kingdom, joined by the Soviet Union, United States and others) and the Axis (at first Nazi Germany, Fascist Italy, Vichy France, and Empire of Japan and others). 
The war in Asia began when Japan invaded China on 7 July, 1937. Combat in Europe began when The Third Reich of Germany invaded Poland on 1 September, 1939. France and the United Kingdom reacted by declaring war on Germany. By 1941, most of Europe was under German control, including France, Norway, Austria, Hungary, Denmark, Czechoslovakia, and Poland. Only the British remained fighting against the Axis in North Africa, the Mediterranean, and the Atlantic. Germany gave up plans to invade Britain after losing the air Battle of Britain. In June 1941, Germany invaded the Soviet Union, starting the largest land invasion in history. On 7 December, 1941, Japan attacked the United States at Pearl Harbor and invaded British and French colonies in Asia, and two fronts developed: the Western Theatre and the Pacific Theatre. 
The Japanese victories were stopped in 1942, and the Soviets won the huge Battle of Stalingrad in early 1943. Then, the Allies started to win in multiple areas. The Axis were forced back from the Soviet Union, weakening in the Scorched Earth tactic. German leaders had not expected the invasion to last until the hard Russian winter. The Axis also lost North Africa. Starting in 1943, they were forced to defend Italy. Allied forces had a hard time pushing into Italy from Sicily due to its strong defenses. In 1944, the Allies invaded France. The invasion was called D-Day, held in 6 June, 1944. They came into Germany itself from the West, while the Soviets came in from the East. Germany surrendered on 8 May, 1945, ending the war in Europe. 
Japan formally surrendered on 2 September, 1945, after the Soviets beat the Japanese in Manchuria and the United States dropped two nuclear bombs, "Little Boy" and "Fat Man," had been dropped on Hiroshima and Nagasaki, respectively. This was the only time a nuclear weapon has been used in a real war. As of the present day, the bombings of Hiroshima and Nagasaki have been the only instances in which nuclear weaponry has been used in wartime. 
After the war, the United Nations was set up to develop support between countries and to prevent future wars. After World War I, the League of Nations had been built, but it proved ineffective. The Cold War by the major winners soon started, but they did not fight each other in an actual war. The decolonization of Asia and Africa (where many places controlled by European countries were given their independence) happened as well since Europe had been weakened by the war. Economic recovery and political integration (the process of uniting countries) were among other results of the war.
 Allies and Axis 
The countries that joined the war were on two sides: the Axis and the Allies.
The Axis Powers at the start of the war were Germany, Italy, and Japan. There were many meetings to create an alliance between those countries. Finland (though they never signed the Tripartite pact like other axis members), Slovakia, Romania, Bulgaria, Hungary, Croatia, Vichy France, and Thailand joined the Axis later. As the war continued, some Axis countries like Italy changed sides to join the Allies instead.
The Allied Powers were the United Kingdom and the rest of the British Empire, France, Poland, Yugoslavia, Greece, Belgium, Denmark, Norway, various south and Central American nations after the Japanese attacks on Pearl Harbour, and Finland after September 1944 the Netherlands Belgium and Luxembourg and China, the last of which had been fighting a civil war. In June 1941, Germany attacked the Soviet Union in Operation Barbarossa, which made the Soviets join the Allies. In December 1941 came the Japanese attack on Pearl Harbor against the United States, which then also joined the Allies (The Finns joined the war against the axis in September 1944).
 Background 
World War I had greatly changed the way of diplomacy and politics in Asia, Europe, and Africa with the defeat of the Central Powers. The empires that had sided with the Central Powers were destroyed. Even the Russian Empire, which was on the Allied side, broke up and became the USSR (Soviet Union) after the Russian Civil War. The war also changed the borders in Eastern Europe, with many new countries being born. Germany was forced to sign the Treaty of Versailles. The Germans also lost 13% of their homeland area and all of their colonies, and they had to pay back a large sum of money to the Allies. The size of their army and navy was also limited, and its air force was banned, except for the 100 airplanes working for the coalmines. 
In Italy, nationalists were unhappy with the Versailles Treaty since they thought that their victory as an Ally in WWI should have gained them far more territory from the defeated Austria. The fascist movement in the 1920s brought Mussolini to the leadership of the country. He promised to make Italy a great power by adding to its colonial empire.
After the Kuomintang (KMT), the governing party of China, unified the country in the 1920s, the Chinese Civil War between it and the Communist Party of China began. In 1931, Japan used the Mukden Incident as a excuse to take Manchuria and set up a puppet state, Manchukuo, and the League of Nations failed to do anything to stop it. The Tanggu Truce, a ceasefire, was signed in 1933. In 1936, the Kuomintang and the communists agreed to stop fighting against each other and to fight Japan instead. In 1937, Japan started the Second Sino-Japanese War to take the rest of China.
After the end of the German Empire, the democratic Weimar Republic was set up. There were disagreements among Germans that involved many political ideologies, ranging from nationalism to communism. The fascist movement in Germany rose because of the Great Depression. Adolf Hitler, the leader of the Nazi Party, became the German chancellor in 1933. After the Reichstag fire, Hitler created a totalitarian state in which there was only one party by law. Hitler wanted to change the world order and quickly rebuilt the army, navy, and air force, especially after Saarland voted to return to Germany in 1935. In March 1936, Hitler sent the army to Rhineland. The Spanish Civil War began in July 1936. The war ended in 1939 with the Nationalist victory because of support from Italy and Germany.
In March 1938, Germany sent its army into Austria, known as the Anschluss, which had little reaction from European countries since many Austrians wanted to be part of Germany. Soon, Western Europe agreed to give Sudetenland, the part of Czechoslovakia that was mostly German, to Germany if Hitler promised to stop taking land. However, the rest of the country had been forced to surrender or be invaded by March 1939. The Allies now tried to stop him by promising to help Poland if it was attacked. Just before the war, Germany and the Soviet Union signed a peace agreement that openly stated that they would not attack each other for ten years. Secretly, they also agreed to divide Eastern Europe between them.
Course of the war
War breaks out
World War II began in Europe on 1 September, 1939, as Germany invaded Poland. On 3 September, Britain and France declared war on Germany. They did not do much to help Poland but sent only a small French attack on Germany from the west. The Soviet Union soon invaded eastern Poland, on 17 September. Finally, all of Poland was divided.
Germany then signed an agreement to work together with the Soviet Union. The Soviet Union forced the Baltic countries to allow it to keep Soviet soldiers in their countries. Finland did not accept the Soviet call, and so it was attacked in November 1939. With peace, the world war broke out. France and Britain thought that the Soviet Union might enter the war for Germany and the Soviets were expelled from the League of Nations.
After Poland was defeated, the Phoney War began in Western Europe. British soldiers were sent to the Continent, but no large battles were fought between the two sides. Then, in April 1940, Germany decided to attack Norway and Denmark so that it would be safer to transport iron ore from Sweden. The British and the French sent an army to disrupt the German occupation, but had to leave when Germany invaded France. Neville Chamberlain was replaced by Winston Churchill as British prime minister in May 1940 because of the invasion.
Axis early victories
On 10 May, Germany invaded France, Belgium, the Netherlands, and Luxembourg and quickly defeated them using massive force tactics. The British were forced to leave mainland Europe at Dunkirk. On 10 June, Italy invaded France and declared war on it and the United Kingdom. Soon, France was divided into occupation zones. Some were directly controlled by Germany and Italy, and the other was the zone of unoccupied Vichy France.
By June 1940, the Soviet Union moved its soldiers into the Baltic states and took them, followed by Bessarabia in Romania. Although there had been some collaboration between the Soviet Union and Germany earlier, that event made it serious. Later, when both countries could not agree to work more closely together, relationships between them became worse to the point of the war.
Germany began an air battle over Britain to prepare for a landing on the island, but the plan was canceled in September when they failed to gain the upper hand. The German Navy destroyed many British ships transporting goods in the Atlantic. Italy had begun its operation in the Mediterranean. The United States remained neutral but started to help the Allies. By helping to protect British ships in the Atlantic, the United States found itself fighting German ships by October 1941 but was not officially at war.
In September 1940, Italy began to invade British-held Egypt. In October, Italy invaded Greece, but that resulted in only an Italian retreat to Italian-occupied Albania. Again, in early 1941, an Italian army was pushed from Egypt to Libya in Africa, but Germany soon helped Italy. Under Erwin Rommel's command, by the end of April 1941, the British were pushed back to Egypt again. Germany also successfully invaded Greece, Yugoslavia and Crete by May. Despite the victories, Hitler decided to cancel the bombing of Britain after 11 May.
Meanwhile, Japan's progress in China was still not much, although the nationalist and communist Chinese began fighting each other again. Japan was planning to take over European colonies in Asia while they were weak, and the Soviet Union could feel a danger from Germany and so a non-aggression pact between the Soviets and the Japanese was signed in April 1941. Germany kept preparing to attack the Soviet Union by moving its soldiers close to the Soviet border.
War becomes global
On 22 June, 1941, the European Axis countries attacked the Soviet Union. This opened a new Eastern Front (World War II). During the summer, the Axis quickly captured Ukraine and the Baltic regions, which caused huge damage to the Soviets. Britain and the Soviet Union formed a military alliance in July. Although there was great progress in the last two months, when winter arrived, the tired German army was forced to delay its attack just outside Moscow. That showed that the Axis had failed its main targets, and the Soviet army was still not weakened. This marked the end of the blitzkrieg stage of the war.
By December, the Soviet Red Army facing the Axis army had received more soldiers from the east since it no longer feared the Japanese. The Soviets began a counterattack and pushed the German army to the west. The Axis lost a lot of soldiers but still had most of the land that it already controlled. By November 1941, the British counterattacked the Axis in North Africa and got all the land back that it had lost. However, the Axis pushed the Allies back again until it was stopped at El Alamein.
In Asia, German successes encouraged Japan to call for oil supplies from the Dutch East Indies. Many Western countries reacted to the occupation of French Indochina by banning oil trading with Japan. Plans to take over European colonies in Asia to create a great defensive area in the Pacific was made by Japan to give it more resources. However, before any future invasion, Japan first had to destroy the American Pacific Fleet in the Pacific Ocean. On 7 December, 1941, it attacked Pearl Harbor as well as many harbors in several South East Asian countries. That event led the United States, United Kingdom, Australia, and the Western Allies to declare war on Japan, but the Soviet Union remained neutral. Most of the Axis nations reacted by declaring war on the United States.
By April 1942 the Singapore strategy had failed and many southeast Asian countries (Burma, Malaya, the Dutch East Indies, and Singapore) had almost fallen to the Japanese. In May 1942, the Philippines fell. The Japanese Navy had many quick victories, but in June 1942, Japan was defeated at Midway. Japan could no longer take the land because a large part of its navy was destroyed during the Battle of Midway.
Allies advance
Japan then began its plan to take over Papua New Guinea again, and the United States planned to attack the Solomon Islands. The fight at Guadalcanal began in September 1942 and involved many troops and ships from both sides. It ended with a Japanese defeat in early 1943.
On the Eastern Front, the Axis defeated Soviet attacks during summer and began its own main offensive to southern Russia along Don and Volga Rivers in June 1942 to try to take over oil fields in Caucasus, which were critical to the Axis for fuelling their war effort, and as well as a great steppe. Stalingrad (now Volgograd) was in the path of the Axis army, and the Soviets decided to defend the city. By November, the Germans had nearly taken Stalingrad, but the Soviets surrounded the Germans in the winter After heavy losses, the German army was forced to surrender the city in February 1943. Even though the front was pushed back farther than it was before the summer attacks, the German Army still had become dangerous to an area around Kursk. Hitler devoted almost two-thirds of his armies to The Battle of Stalingrad, which was the largest and deadliest battle at the time.
In August 1942, because of the Allied defense at El Alamein, the Axis army failed to take the town. A new Allied offensive drove the Axis west across Libya a few months later, just after the Anglo-American invasion of French North Africa forced it to join the Allies. That led to Axis defeat during the North African Campaign in May 1943.
In the Soviet Union, on 4 July, 1943, Germany started an attack around Kursk. Many German soldiers were lost because of the Soviets' well-created defenses. Hitler cancelled the attack before it had any clear outcome. The Soviets then started their counterattack, which was one of the war's turning points. The Soviets, instead of the Germans, then became the attacking force on the Eastern Front.
On 9 July, 1943, affected by the earlier Soviet victories, the Western Allies landed on Sicily, which resulted in the arrest of Mussolini in the same month. In September 1943, the Allies invaded mainland Italy, following the Italian armistice with the Allies. Germany then took control of Italy, disarmed its army, and built many defensive lines to slow the Allied invasion. German special forces rescued Mussolini and created the German-occupied puppet state of the Italian Social Republic. In late 1943, Japan conquered some islands in India and began an invasion of the mainland of India. The British Indian Army and other forces expelled it in early 1944.
In early 1944, the Soviet army drove off the German army from Leningrad (now Saint Petersburg) and ended the longest and deadliest siege in history. After that, the Soviets began a large counterattack. By May, the Soviets had retaken Crimea. With the attacks in Italy from September 1943, the Allies succeeded in capturing Rome on 4 June, 1944, and made the German forces fall back.
The Italians in the far east were in a difficult situation after September 1943. They would neither surrender to Japan nor declare war on Japan. The Chinese leaders moved the headquarter and military bases to western China. That was due to 6 years' aggression of Japan. They did not pay much attention on the Italy during that period of time. Italy decalred war on Japan in July 1945.
War ends in Europe
 Approaching Omaha.jpg
  Allied forces arriving Normandy, France, on (June 6, 1944)
  AmericanAndSovietAtElbe.jpg
  American and Soviet soldiers meeting east of the Elbe river, Germany 
On D-Day, on 6 June, 1944, the Allies began the invasion of Normandy, France. The codename for the invasion was Operation Overlord. The successful invasion led to the defeat of the German forces in France. Paris was freed in August 1944, and the Allies continued eastward while the German front collapsed. Operation Market Garden was the combined aerial invasion of the Netherlands and was launched on 17 September, 1944. The purpose was to seize a series of bridges that included a bridge in Arnhem, which spanned the Rhine River. The airborne invasion was called Market. The ground invasion, named Garden, reached the Rhine but could not take the bridge.
On 22 June, the Soviet offensive on the Eastern Front codenamed Operation Bagration, destroyed almost all of the German Army Group Centre. Soon, the Germans were forced to retreat and to defend Ukraine and Poland. The arriving Soviet troops caused uprisings against the German government in Eastern European countries, but they failed to succeed unless they were helped by the Soviets. Another Soviet offensive forced Romania and Bulgaria to join the Allies. Communist Serbian partisans under Josip Broz Tito retook Belgrade with some help from Bulgaria and the Soviet Union. By early 1945, the Soviets had attacked many German-occupied countries: Greece, Albania, Yugoslavia, and Hungary. The Soviets made Finland switch to the Allies.
On 16 December, 1944, the Germans tried one last time to take the Western Front by attacking the Allies in Ardennes, Belgium, in a battle known as the Battle of the Bulge. It was the last major German war attack, and the Germans were unsuccessful in their attack.
By March 1945, the Soviets had moved quickly from Vistula River in Poland to East Prussia and Vienna, and the Western Allies had crossed the Rhine. In Italy, the Allies pushed forward while the Soviets attacked Berlin. The Western Allies eventually met up with the Soviets at the Elbe River on 25 April 25, 1945.
Hitler committed suicide on 30 April, 1945, two days after Mussolini had been killed. In his will, Hitler appointed his navy commander, Grand Admiral Karl Donitz, to be his successor. Donitz surrendered to the allies, and opposed Hitler for wanting Germany to continue fighting.
End of war in Europe
German forces in Italy surrendered on 29 April, 1945. Germany surrendered to the Western Allies on 7 May, 1945, known as V-E Day, and was forced to surrender to the Soviets on 8 May, 1945. The final battle in Europe ended in Czechoslovakia, on 11 May, 1945.
End of war in Asia
In the Pacific, American forces arrived in the Philippines in June 1944. By April 1945, American and Philippine forces had cleared many of the Japanese forces, but fighting continued in some parts of the Philippines until the end of the war. British and Chinese forces had advanced in Northern Burma and captured Rangoon by 3 May, 1945. American forces had taken Iwo Jima by March and Okinawa by June 1945. Many Japanese cities were destroyed by Allied bombings, and Japanese imports were cut off by American submarines.
The Allies wanted Japan to surrender without conditions, but Japan refused to do so. The United States dropped two atomic bombs over Hiroshima (6 August, 1945) and Nagasaki (9 August, 1945). On 8 August, 1945, the Soviets entered the war against Japan and invaded Manchuria and quickly defeated the primary Imperial Japanese Army there. On 15 August, 1945, Japan surrendered to the Allies. The surrender documents were formally signed on board the USS Missouri on 2 September, 1945, which ended the war.
 Aftermath 
The Allies managed to occupy Austria and Germany. Germany was divided into four. The Soviets controlled the east, and the United States, United Kingdom, and France controlled the west. The Allies began denazification, removing Nazi ideas from public life in Germany, and most high-ranking Nazis were captured and brought to a special court. Germany lost a quarter of its land in 1937, mostly to Poland and the Soviet Union. The Soviets also took some parts of Poland and Finland as well as the three Baltic countries. The United Nations was formed on 24 October, 1945 to keep peace between countries in the world. However, the relationship between the Western Allies and the Soviet Union had worsened during the war and, soon after it, each power quickly built up their power over the controlled area. In Western Europe and West Germany, it was the United States, while in East Germany and Eastern Europe, it was the Soviet Union, which turned many countries into communist states. The Cold War led to the formation of the American-led NATO and the Soviet-led Warsaw Pact.
In Asia, Japan was put under American occupation. In 1948, Korea was divided into North Korea and South Korea, each claiming to be the legal representative of the Koreans, which led to the Korean War in 1950. The civil war in China continued from 1946 and resulted in the KMT retreating to Taiwan in 1949 after the communists had won the mainland. In the Middle East, the Arabs' disagreed with the United Nations plan to create Israel, which marked the beginning of conflicts between the Arabs and Israel.
 Cold war europe military alliances map en.png
  Military alliances in Europe after the war
  Colonization 1945.png
  Colonies around the world in 1945. However, many countries in Asia and Africa would become free later.
After the war, decolonization took place in many European colonies. Bad economies and people wanting to rule themselves were the main reasons. In most cases, that happened peacefully, except in some countries, such as Indochina and Algeria. In many regions, European withdrawal caused divisions among the people who had different ethnic groups or religions.
Economic recovery was different in many parts of the world, but in general, it was quite positive. The United States became richer than any other country; by 1950, it had taken over the world's economy. It also decided on the Marshall Plan (1948–1951) to help European countries. The German, Italian, and French economies recovered. However, the British economy was badly harmed and continued to worsen for more than ten years. The Soviet economy grew very fast after the war was over. That also happened with the Japanese economy, which became one of the largest economies in the 1980s. China returned to the same production level as before the war by 1952.
 Effects 
 Death and war crimes 
There is no exact number of deaths because many were unrecorded. Many studies said that more than 60 million people died in the war, mostly civilians. The Soviet Union lost around 27 million people, almost half of the recorded number of deaths, which means that 25% of the Soviets were killed or wounded in the war. About 85% of the total deaths were on the Allies, and the other 15% were on the Axis. Mostly, people died because they were sick, hungry to death, bombed, or the wrong ethnicity.
The Nazis selected many groups of people to be killed in what is known as known as The Holocaust. They killed Jews, Roma, Poles, Russians, homosexuals, and other groups. Around 11 million to 17 million civilians died. Around 7.5 million people were killed in China by the Japanese. The most well-known Japanese crime is the Nanking massacre, in which hundreds of thousands of Chinese civilians were raped and murdered. There were reports that the Germans and Japanese tested biological weapons against civilians and against prisoners-of-war.
Although many Axis war crimes were brought to the first international court, no Allied war crimes were.
 Concentration camps and slave work 
Other than the Holocaust, about 12 million people, mostly Eastern Europeans, were forced to work for the German economy. German concentration camps and Soviet gulags caused many deaths. Both sides treated prisoners of war badly. That was the case even for Soviet soldiers who survived and returned home.
Japanese prisoner-of-war camps, many of which were used as labor camps, also caused many deaths. The death rate of Western prisoners was 27.1%, seven times that of prisoners under Germans and Italians. More than 10 million Chinese civilians were made slaves and had to work in mines and war factories. Between 4 and 10 million people were forced to work in Java.
Between 1942 and 1945, US President Franklin Roosevelt signed an order that made Japanese Americans go to internment camps since he feared them helping an invasion. Some Germans and Italians were included as well.
The Allies agreed that the Soviet Union could use prisoners of war and civilians for forced labor. Hungarians were forced to work for the Soviet Union until 1955.
 Home fronts and production 
Before the war in Europe, the Allies had a larger population and economy than the Axis. If colonies were included, the GDP of the Allies would be twice that of the Axis. In Asia, however, China had a GDP only 38% higher than Japan if colonies were counted.
The Allied economy and population compared with the Axis lessened with the early Axis victories. However, that was no longer the case after the United States and the Soviet Union joined the Allies in 1941. The Allies had a higher production level than the Axis because of more natural resources. Also, Germany and Japan did not plan for a long war and even had no ability to do so. Both tried to improve their economies by using slave laborers.
 Women 
As men went off to fight, women took over many of the jobs that they left behind. At factories, women were employed to make bombs, guns, aircraft, and other equipment. In Britain, thousands of women were sent to work on farms as part of the Land Army. Others formed the Women's Royal Naval Service to help with building and repairing ships. Even Princess Elizabeth, who later became Queen Elizabeth II, worked as a mechanic to aid the war effort. By 1945, some weapons were being made almost entirely by women.
In the beginning, women were rarely used in the labor forces in Germany and Japan. However, Allied bombings and the German change to a war economy made women take a greater part.
In Britain, women also worked in gathering intelligence at Bletchley Park and other places. The mass evacuation of children also had a major impact on the lives of mothers during the war years.
 Occupation 
Germany had two different ideas of how it would occupy countries. In Western, Northern, and Central Europe, Germany set economic policies that would make it rich. During the war, the policies brought as much as 40% of total German income. In the east, the war against the Soviet Union meant Germany could not use the land to gain resources. The Nazis used their racial policy and murdered a lot of people they thought were non-human. The Resistance, the group of people secretly fighting Germany, could not harm Germany much until 1943.
Japan claimed to free colonized Asian countries from European colonial powers in Asia. Although it was welcomed at first in many territories, its cruel actions soon turned people against it. During the occupation, Japan used 4 million barrels of oil that had been left behind by the Allies. By 1943, Japan produced up to 50 million barrels of oil in the Dutch East Indies, was 76% of its 1940 rate.
 Developments in technology 
The war brought new methods for future wars. The air forces improved greatly in fields such as air transport, strategic bombing to use bombs to destroy industry and morale, radar, and weapons for destroying aircraft. Jet aircraft were developed and were used worldwide in air forces.
At sea, the war focused on using aircraft carriers and submarines. Aircraft carriers soon replaced battleships, mainly for being cheaper. Submarines, a deadly weapon since World War I, also played an important part in the war. The British improved weapons for destroying submarines, such as sonar, while the Germans improved submarine tactics.
The style of war on the land had changed from World War I to be more mobile. Tanks, which had been used to support infantry, changed to being primary weapons. The tank was improved in speed and firepower during the war. At the start of the war, most commanders thought that using better tanks was the best way to fight enemy tanks. However, early tanks could harm armour only a little. The German idea to avoid letting tanks fight each other meant tanks facing tanks rarely happened. That was a successful tactic in Poland and France. Ways to destroy tanks also improved. Vehicles became more used in the war, infantry remained the main part of the army.
Submachine guns became widely used, especially in cities and jungles. The assault rifle, a German development combining features of the rifle and submachine gun, became the main weapon for most armies after the war.
Other developments included better encryption for secret messages, such as the German Enigma. Another feature of military intelligence was the use of deception, especially by the Allies. Others include the first programmable computers, modern missiles and rockets, and the atomic bombs.
 Losses 
 Military losses 
Most authorities now agree that of the 30 million Soviets who fought, there were 13.6 million military deaths.
- Total of which 7,800,000 were battlefield deaths
- Including Australia, Canada, India, New Zealand, etc.
 Civilian losses 
Deaths among civilians during this war, many of which resulted from famine and internal purges, such as in China and the Soviet Union, were colossal but less well documented than those by the fighting forces. Although the figures are the best available from authoritative sources and present a broad picture of the scale of civilian losses, the precise numbers will never be known.
Axis Powers
Germany, Italy, Japan, Hungary, Romania, Bulgaria, Thailand, Croatia
Allied Powers
United States, British Empire, France, Soviet Union, Australia, Belgium, Brazil, Canada, China, Denmark, Greece, Netherlands, New Zealand, Norway, Poland, South Africa, Yugoslavia
There is no exact number of deaths because many were unrecorded. Many studies said that more than 60 million people died in the war, mostly civilians. The Soviet Union lost around 27 million people, almost half of the recorded number of deaths, which means that 25% of the Soviets were killed or wounded in the war. About 85% of the total deaths were on the Allies, and the other 15% were on the Axis. Mostly, people died because they were sick, hungry to death, bombed, or the wrong ethnicity.
The Nazis selected many groups of people to be killed in what is known as known as The Holocaust. They killed Jews, Roma, Poles, Russians, homosexuals, and other groups. Around 11 million to 17 million civilians died. Around 7.5 million people were killed in China by the Japanese. The most well-known Japanese crime is the Nanking massacre, in which hundreds of thousands of Chinese civilians were raped and murdered. There were reports that the Germans and Japanese tested biological weapons against civilians and against prisoners-of-war.
Although many Axis war crimes were brought to the first international court, no Allied war crimes were.


Lynching in the United States: Lynching is a form of murder. It is normally by hanging. Lynching is often by a group of people as a form of punishment. In the United States, lynchings happened more often after the American Civil War in the early-to-mid 1860s.
Although the number of lynchings went down in the 1920s, they have continued into the 21st century.
Most, but not all, lynchings were of African American men in the South. Ninety-two women were lynched in the United States between 1882 and 1927. The lynchings of black people by white people happened in the Midwest and border states. There were also lynchings of Native Americans, Hispanics and Asian Americans in the West. White people were also lynched but these lynchings were less common. 
According to the Tuskegee Institute, 4,743 people were lynched between 1882 and 1968 in the United States. This includes 3,446 African Americans and 1,297 whites. More than 73 percent of lynchings after the Civil War happened in the Southern states. According to the Equal Justice Initiative, 4,084 African-Americans were lynched between 1877 and 1950 in the South. Whites lynched blacks to defend white supremacy. Blacks were lynched for violating social norms, including segregation (the separation of whites and blacks), and the lower status of blacks. White acted together to lynch an individual black person. In the Deep South, lynching was also used to scare blacks away from voting.
After the Civil War, nearly four million slaves in the South were made free. In some states and many counties, freed blacks made up over half the people who lived there. The first Ku Klux Klan was founded in 1866 by Confederate veterans in Tennessee. Ku Klux Klan groups were then founded by veterans throughout the South. They wanted to keep African Americans in fear, as they were before the war. This was when lynchings became common. In the 1890s, African American journalist and anti-lynching fighter Ida B. Wells was one of the first people to study lynching cases. She found that black lynching victims were accused of rape or attempted rape about one-third of the time. The most common accusation was murder or attempted murder. Other accusations were verbal and physical aggression, competitive businesses and independent thinking. In 1940, sociologist Arthur F. Raper investigated one hundred lynchings after 1929. He said that about one-third of the victims were falsely accused.
The stereotype of lynching is hanging. Hangings are what crowds of people saw. Hanging is also easy to photograph. There are other forms of lynching. They include being shot repeatedly, being burned, dragged behind cars and being forced to jump from a bridge.
In the late-1800s to early-1900s South, photographs were taken at lynchings. These were used in postcards and newspapers. These images usually showed an African-American lynching victim and all or part of the crowd that attended. Women and children often watched lynchings. The people who killed the victim were not identified. At one lynching, nearly 15,000 people were in the crowd. Often lynchings were advertised in newspapers before the event so photographers could be there. After the lynching, photographers would sell their pictures as-is or as postcards. They could cost as much as fifty cents each, or $9, as of 2016.
Background
Collective violence was a familiar aspect of the early American legal landscape, with group violence in colonial America being usually nonlethal in intention and result. In the 17th century, in the context of the Wars of the Three Kingdoms in the British Isles and unsettled social and political conditions in the American colonies, lynchings became a frequent form of "mob justice" when the authorities were perceived as untrustworthy. In the United States, during the decades after the Civil War, African Americans were the main victims of racial lynching, but in the American Southwest, Mexican Americans were also the targets of lynching as well.
At the first recorded lynching, in St. Louis in 1835, a Black man named McIntosh (who killed a deputy sheriff while being taken to jail) was captured, chained to a tree, and burned to death on a corner lot downtown in front of a crowd of more than 1,000 people.
According to historian Michael J. Pfeifer, the prevalence of lynchings in post–Civil War America reflected people's lack of confidence in the "due process" of the U.S. judicial system. He links the decline in lynchings in the early 20th century to "the advent of the modern death penalty", and argues that "legislators renovated the death penalty...out of direct concern for the alternative of mob violence". Between 1901 and 1964, Georgia hanged and electrocuted 609 people. Eighty-two percent of those executed were Black men, even though Georgia was majority white. Pfeifer also cited "the modern, racialized excesses of urban police forces in the twentieth century and after" as bearing characteristics of lynchings.Pfeifer 2004 7–9
Lynching demographics (worst years for lynchings in the United States)
African American resistance
African Americans resisted lynchings in numerous ways. Intellectuals and journalists encouraged public education, actively protesting and lobbying against lynch mob violence and government complicity. The National Association for the Advancement of Colored People (NAACP), and related groups, organized support from white and Black Americans, publicizing injustices, investigating incidents, and working for passage of federal anti-lynching legislation (which finally passed as the Emmett Till Anti-Lynching Act on March 29, 2022). African-American women's clubs raised funds and conducted petition drives, letter campaigns, meetings, and demonstrations to highlight the issues and combat lynching. In the great migration, particularly from 1910 to 1940, 1.5 million African Americans left the South, primarily for destinations in northern and mid-western cities, both to gain better jobs and education and to escape the high rate of violence. From 1910 to 1930 particularly, more Blacks migrated from counties with high numbers of lynchings.
African-American writers used their talents in numerous ways to publicize and protest against lynching. In 1914, Angelina Weld Grimké had already written her play Rachel to address racial violence. It was produced in 1916. In 1915, W. E. B. Du Bois, noted scholar and head of the recently formed NAACP, called for more Black-authored plays.
African American female playwrights were strong in responding. They wrote ten of the 14 anti-lynching plays produced between 1916 and 1935. The NAACP set up a Drama Committee to encourage such work. In addition, Howard University, the leading historically Black college, established a theater department in 1920 to encourage African-American dramatists. Starting in 1924, the NAACP's major publications The Crisis and Opportunity sponsored contests to encourage Black literary production.McCaskill Gebhard 2006 210–212
African Americans emerged from the Civil War with the political experience and stature to resist attacks, but disfranchisement and imposition of Jim Crow in the South at the turn of the 20th century closed them out of the political system and judicial system in many ways. Advocacy organizations compiled statistics and publicized the atrocities, as well as working for enforcement of civil rights and a federal anti-lynching law. From the early 1880s, the Chicago Tribune reprinted accounts of lynchings from other newspapers, and published annual statistics. These provided the main source for the compilations by the Tuskegee Institute to document lynchings, a practice it continued until 1968.
In 1892, journalist Ida B. Wells-Barnett was shocked when three friends in Memphis, Tennessee, were lynched. She learned it was because their grocery store had competed successfully against a white-owned store. Outraged, Wells-Barnett began a global anti-lynching campaign that raised awareness of these murders. She also investigated lynchings and overturned the common idea that they were based on Black sexual crimes, as was popularly discussed; she found lynchings were more an effort to suppress Blacks who competed economically with Whites, especially if they were successful. As a result of her efforts at education, Black women in the U.S. became active in the anti-lynching crusade, often in the form of clubs that raised money to publicize the abuses. When the National Association for the Advancement of Colored People (NAACP) was formed in 1909, Wells became part of its multi-racial leadership and continued to be active against lynching. The NAACP began to publish lynching statistics at their office in New York City.
In 1898, Alexander Manly of Wilmington, North Carolina, directly challenged popular ideas about lynching in an editorial in his newspaper The Daily Record. He noted that consensual relationships took place between white women and Black men, and said that many of the latter had white fathers (as he did). His references to miscegenation lifted the veil of denial. Whites were outraged. A mob destroyed his printing press and business, ran Black leaders out of town and killed many others, and overturned the biracial Populist-Republican city government, headed by a white mayor and majority-white council. Manly escaped, eventually settling in Philadelphia, Pennsylvania.
In 1903, writer Charles W. Chesnutt of Ohio published the article "The Disfranchisement of the Negro", detailing civil rights abuses as Southern states passed laws and constitutions that essentially disfranchised African Americans, excluding them wholesale from the political system. He publicized the need for change in the South. Numerous writers appealed to the literate public.
Statistics
Statistics for lynchings have traditionally come from three sources primarily, none of which covered the entire historical time period of lynching in the United States. Before 1882, no contemporaneous statistics were assembled on a national level. In 1882, the Chicago Tribune began to systematically tabulate lynchings nationally. In 1908, the Tuskegee Institute began a systematic collection of lynching reports under the direction of Monroe Work at its Department of Records, drawn primarily from newspaper reports. Monroe Work published his first independent tabulations in 1910, although his report also went back to the starting year 1882. Finally, in 1912, the National Association for the Advancement of Colored People started an independent record of lynchings. The numbers of lynchings from each source vary slightly, with the Tuskegee Institute's figures being considered "conservative" by some historians.
Based on the source, the numbers vary depending on which sources are cited, the years that are considered by those sources, and the definitions that are given to specific incidents by those sources. The Tuskegee Institute has recorded the lynchings of 3,446 Blacks and the lynchings of 1,297 Whites, all of which occurred between 1882 and 1968, with the peak occurring in the 1890s, at a time of economic stress in the South and increasing political suppression of Blacks. A six-year study published in 2017 by the Equal Justice Initiative found that 4,084 Black men, women, and children fell victim to "racial terror lynchings" in twelve Southern states between 1877 and 1950, besides 300 that took place in other states. During this period, Mississippi's 654 lynchings led the lynchings which occurred in all of the Southern states.
The records of Tuskegee Institute remain the single most complete source of statistics and records on this crime since 1882 for all states, although modern research has illuminated new incidents in studies focused on specific states in isolation. As of 1959, which was the last time that Tuskegee Institute's annual report was published, a total of 4,733 persons had died by lynching since 1882. The last lynching recorded by the Tuskegee Institute was that of Emmett Till in 1955. In the 65 years leading up to 1947, at least one lynching was reported every year. The period from 1882 to 1901 saw the height of lynchings, with an average of more than 150 each year. 1892 saw the most number of lynchings in a year: 231 or 3.25 per one million people. After 1924 cases steadily declined, with less than 30 a year. The decreasing rate of yearly lynchings was faster outside the South and for white victims of lynching. Lynching became more of a Southern phenomenon and a racial one that overwhelmingly affected Black victims. There were measurable variations in lynching rates between and within states.


Boro language (India): brx
Bodo (बर') or Boro is a Sino-Tibetan language spoken primarily by the Bodo people of Northeast India. It is official language of the Bodoland autonomous region and co-official language of the state of Assam in India. It is also one of twenty two languages listed in the Eighth Schedule of the Constitution of India. The Bodo language has been written using Devanagari script since 1963. Some scholar believe that at ancient time boro language were written in Deodhai script which is now lost.
History and linguistic classification
Bodo is a Sino-Tibetan language of the Bodo group. It is closely related to the Dimasa language and Tiwa (Lalung) Language of Assam. It is also related to the Garo language of Meghalaya and the Kokborok language of Tripura. The Bodo speaking areas of Assam stretch from Dhubri in the west to Sadiya in the east. In Alipurduar, Cooch Behar and Jalpaiguri and other parts of Bengal, the Boros are known as "Mech". According to the 1991 census, the population of Boro speakers was 1,984,569 (Bodo 1,324,748), (Mech 659,821). The census reports of Bodo tribe, however, includes only the Bodos. It excludes the Mech tribe. The word "Boro" means the language and the community. It is pronounced with a high tone on the second syllable.
 Dialects 
The dialects spoken in this area can be divided into three main groups:
The Western Boro dialect, {(Sønabari) WBD}:
The Eastern Boro dialect, {(Sanzari) EBD} and
The Southern Boro dialect, {(Hazari) SBD}.
The Western Boro dialects are spoken in the districts of Kokrajhar and Bongaigaon. The Eastern Bodo dialects are found mainly in the districts of Barpeta, Nalbari and Kamrup and some parts of Darrang. The Western Boro dialect has gained the status of a standard dialect. It has also developed a written form. The variations between these two dialect groups are mainly phonological and lexical.
The Bodo language of Assam has at least four clear-cut dialect-areas with a sufficient number of dialectal variations. There are the northeastern, southwestern, north-central and southern dialect areas. Each has distinct differences.
Geographic distribution
Ethnologue lists the following districts where Bodo is spoken. Bodo is spoken mainly in the lowlands and foothills of Assam and West Bengal.
Assam
Darrang district
Chirang district
Baksa district
Udalguri district
Barpeta district
Bongaigaon district
Kokrajhar district
Nagaon district
Kamrup district
Goalpara district
Sibsagar district
Lakhimpur district
Dhemaji district
West Bengal
Kolkata
Jalpaiguri district
Cooch Behar district
Manipur
Chandel district (in Tengnoupal)
Meghalaya
7 villages in Tikrikilla block of West Garo Hills district
East Khasi Hills district
 History 
Although the Bodo language is a rich and ancient language, it did not have any written literature until the second decade of the 20th century. Christian missionaries, who entered the Bodo speaking areas to preach their religion, published some books on religion, tales, rhymes and songs. These missionaries also published some books on grammar and dictionary. Reverend Sidney Endle compiled An Outline of the Kachari Grammar in 1884. The grammar is based on the dialect of Darrang district. Endle also wrote an important book on the Bodos. It is titled The Kacharis. The book was published in 1911 and it contains chapters on social customs, agriculture practices, festivities, food habits, rituals, crafts and textiles of the Bodos. The book also included examples of Bodo folktales, rhymes and grammars. J.D. Anderson's Collection of Bodo Folktales and Rhymes (1895) included seventeen Bodo folktales translated into the English language. This is in addition to the original versions in the Bodo language.
In 1963 the language was used in teaching in the primary schools in Bodo dominated areas. The Bodo language is used in schools up to the secondary level. The language has become a matter of pride with the opening of the post-graduate course in the Bodo language. Bodo literature has been used in the University of Guwahati since 1996. The Bodo language now has a large number of books of poetry, drama, short stories, novels, biography, travel, children's literature and literary criticism. Though the spoken language has been affected by other communities and dialects, it is still to be heard in its pure form in and around the Udalguri district.
 Writing system 
The language is officially written using the Devanagari script. It also has a long history of using the Latin script and the Assamese script. Some researchers have suggested that at one time the language used a now-lost script called Deodhai.


Renaissance: The Renaissance is a period in European history that followed the Middle Ages and ended in the 17th century. Renaissance is a French word for “cultural rebirth.” During this period, there was a “rebirth” of classical learning. People started relearning the teachings of scholars from Ancient Greece, Rome, and other ancient societies. The Renaissance is often said to be the start of the modern age.
During the Renaissance, there were many advances in art, literature, the sciences, mathematics, and culture. Many famous artists, writers, philosophers, and scientists lived during this period. A person who is clever at a great number of things is sometimes called a "Renaissance man." The most famous Renaissance man was Leonardo da Vinci, a painter, scientist, musician, and philosopher.
The Renaissance started in Italy but soon spread throughout Europe. In Italy, the period is divided into three parts:
 the Early Renaissance
 the High Renaissance
 the Late Renaissance <ref></ref>(also called the "Mannerist period") https://web.archive.org/web/20160420230812/https://www.khanacademy.org/humanities/renaissance-reformation/mannerism1/a/a-beginners-guide-to-mannerism 2016-04-20 
Following the Mannerist period was the Baroque period, which also spread across Europe starting around 1600. Outside Italy, it can be hard to tell when the Renaissance period ended and the Baroque began.
 Causes 
 Reading and printing 
In the Middle Ages, most artistic, legal, and historical production took place in and around books. Monasteries, churches, universities, and rich people them produced and owned books. They were produced entirely by hand and so were called manuscripts; illuminated manuscripts include handcolored, drawn, and gilded pictures.
Most books were written in Greek or Latin, which was used in the Catholic Church. Only priests and well-educated people could read Latin. People were forbidden by church law from translating the Bible into Italian, English, German, French, or other local languages.
Around 1440, the first printed books were made in Europe. The printing press made it possible to print copies of large books like the Bible and to sell them cheaply. It took 300 calf skins or 100 pig skins to print the Bible. Printers soon began to print everything that they thought was interesting: Ancient Greek and Roman writings, poetry, and plays; stories about the lives of the saints; mathematics textbooks; medical textbooks; Christian stories; erotic stories; books about animals and monsters; maps of the world; and advice to princes about on to rule.
Before the invention of the printing press, knowledge had belonged to priests, monasteries, and universities. Suddenly many thousands of people, even merchants, could learn far more than they ever could before.
 Ancient Roman things 
From about 400 BC to 400 AD, Europe experienced a Golden Age. In Ancient Greece and Rome, there were many philosophers, writers, painters, sculptors, architects and mathematicians. Things were beautiful, well-organized, and well run.
However, by the year 1400, the city of Rome was in ruins. Inside the broken walls, which had been smashed in 410 AD, were the remains of huge temples, sports arenas, public baths, apartment blocks and palaces. Nearly all of them were half-buried and ruined and so they could not be used. Many were pulled down to use as building stone.
Among the ruins of the once-great city, the people of Rome lived in cottages. They still went to church in the huge churches (basilicas) that had been built by the first Christian emperor, Constantine the Great, in the 4th century. They still held market day in the ancient Roman market place of Campo dei Fiori ("Field of Flowers").
In 1402, Filippo Brunelleschi and the teenager Donatello came to Rome. They were probably the world's first archaeologists. They were fascinated by everything that they saw. They measured ancient ruined buildings, drew things, and dug around for weeks looking for bits of broken statues and painted pottery that they could put back together. When they went back home to Florence, they knew more about ancient Roman architecture and sculpture than anyone had known for about a thousand years. Brunelleschi became a very famous architect, and Donatello became a very famous sculptor.
 Money and politics 
The Renaissance really began in the city of Florence. In those days, Italy was not one single country but was made of many little states. All of them were governed in different ways and were constantly making alliances and fighting one other.
Rome was politically powerfu, because the city had the Pope, the head of the Roman Catholic Church. Because of his very great importance as a spiritual leader, most people and most cities did not want to argue with him. After a pope died, a new pope was elected. Rich and powerful people hoped that a member of their family would be chosen. It was always a good idea to have several young men in the family trained as priests just in case. It also helped to be good friends with other rich families. One way to do so was to have many daughters and to get them to marry rich and powerful men from different cities, which was how politics then worked.
There were other powerful cities in Italy. Venice had a large and powerful navy. Milan controlled trade with Northern Europe and was very rich. Genoa was also very rich because it controlled trade with France and Spain. Florence, where the Renaissance is said to have started, was another important city.
Florence’s strength came from a strong army, strong fortress, or control over trade but came from banking. The ruling Medicis were an important banking family and helped to make Florence a powerful city and the centre of Renaissance learning.
 List of important events of the Renaissance 
 In art 
 1401: Lorenzo Ghiberti wins a competition to create the Florence Baptistry Doors. Over the next 21 years, he creates two famous bronze doors with relief sculptures showing religious scenes.
 1420s: Masaccio and Masolino paint the Brancacci Chapel in Florence.
 1440s: Donatello makes the statue of Gattamelata on Horseback in Padua.
 1470s: Botticelli paints the Birth of Venus in Florence.
 1490s: Leonardo da Vinci paints The Last Supper and the Mona Lisa in Milan.
 1508-1512: Michelangelo paints the Sistine Chapel Ceiling in Rome.
 In architecture 
 1420: Workers begin to build The Dome of Florence Cathedral, using Brunelleschi's design.
 1420s: Filippo Brunelleschi designs the Church of San Lorenzo in Florence.
 1444: Michelozzo designs the Medici-Riccardi Palace for Cosimo de' Medici.
 1471: Leon Battista Alberti designs the Church of Sant' Andrea in Mantua.
 1506: Work begins on the new St. Peter's Basilica in Rome.
 1550: Andrea Palladio designs the Villa Rotunda near Vicenza.
 In science and technology 
 Early 1300s: The first guns are made.
 1455: Johannes Gutenberg invents the printing press and uses it to create the first printed book in Europe.
 Late 1400s: The quadrant was developed to help sailors find their way at sea.
 1480s: Leonardo da Vinci studies human anatomy.
 1550s: Peter Henlein of Nuremberg makes the first watches.
 1608: Hans Lippershey of the Netherlands makes the first telescope.
 1618, William Harvey discovered that the heart pumps blood.
 In thinking 
(See illustration above: Raphael's "School of Athens")
 Early 1300s: Petrarch publishes writings based on the works of St. Augustine and other classical writers.
 Mid 1400s: The Humanist Academy is created to discuss ancient writings and modern ideas. The Medicis supports the academy financially.
 1511: Erasmus publishes In Praise of Folly, which satirizes the traditions of the Catholic Church.
 1532: Machiavelli publishes The Prince and states that people who wish to have political power often do wicked things to get it.
 In religion 
 1382: John Wycliffe first translates the Bible from Latin to English. A movement begins to translate the Bible io many other European languages.
 1454-1455: Johannes Gutenberg prints his famous Bible. The mass production of Bibles begins.
 1517: Martin Luther writes the Ninety-Five Theses on his ideas about problems in the Catholic Church, which is an important event in the Reformation.
 1534: Henry VIII splits from the Catholic Church to form the Church of England.
 1545: Pope Paul III calls the Council of Trent. Catholic leaders meet and discuss the problems that the Reformation has caused for the Catholic Church, which is the beginning of the Counter-Reformation.
 1559: John Calvin starts the Geneva Theological Academy to teach people the Reformation's ideas about Christianity.
 In writing 
 Early 1300s: Dante Alighieri writes The Divine Comedy in Italy.
 1348: Giovanni Boccaccio starts writing a collection of stories called The Decameron in Italy.
 1477: William Caxton publishes The Canterbury Tales, which was written in the 1300s by Geoffrey Chaucer. It is the first important book written in English in England.
 1532 and 1534: François Rabelais writes Pantagruel and Gargantua in France.
 1550: Giorgio Vasari publishes Lives of the Great Architects, Painters and Sculptors of Italy in Italy.
 1590-1612: William Shakespeare writes his 37 plays in England.
 1605 and 1616: Miguel de Cervantes publishes the tale of Don Quixote, Man of La Mancha'' in Spain.
 In exploration 
 1487-1488: Bartholomeu Dias sails down the coast of Africa to the Cape of Good Hope.
 1492: Christopher Columbus sails from Spain across the Atlantic Ocean to the West Indies.
 1497-1499: Vasco da Gama sails from Portugal to India by going around Africa.
 1519-1522: Ferdinand Magellan leads an expedition to sail around the world. The expedition is completed under the command of Juan Sabastian del Cano.
 1577-1580: Sir Francis Drake completes from England the second voyage around the world.


Presidency of Abraham Lincoln: The presidency of Abraham Lincoln began on March 4, 1861, when Abraham Lincoln was inaugurated as the 16th President of the United States and ended upon his death on April 15, 1865. During his presidency he claimed more prerogatives than any other president had done before him. As a result, the small and relatively limited powers of the president grew enormously during his time in office. When Lincoln won the 1860 presidential election, he did it without the support of any of the Southern states. Since the 1830s, Southern states had talked about secession, but it became a serious issue in 1860. Between the election and Lincoln's Inauguration in March of 1861, seven states had seceded from the Union. They formed the Confederate States of America (CSA). When Confederates attacked Fort Sumter on April 12, 1861 and captured it the next day, this started the American Civil War. While having little previous military experience, Lincoln still managed to stand out as a great war president. In 1863, his Emancipation Proclamation freed the slaves in Southern states. It led directly to the abolition of slavery in the United States. Given later that year, his Gettysburg Address is and remains one of the most important speeches in American history. In 1865, as the Civil war was ending he was shot and killed by John Wilkes Booth, a Confederate sympathizer. His death made Lincoln a martyr to the Union cause. He is widely recognized as the greatest president in U.S. history.
 Lincoln's 1860 presidential campaign 
By this time Lincoln was well-known in Illinois politics. In 1858 he had debated Stephen A. Douglas in a bid for the United States Senate and lost. At the time, U.S. senators were elected by their state legislatures. So both Lincoln and Douglas were trying for their respective parties to win control of the Illinois legislature. Although Illinois was a free state, the main issue of all seven debates was slavery.
Lincoln spent the next 16 months making speeches for a number of Republican candidates in the North. This both made him many political friends and also was in preparation for his run for President. Up to this time the strongest candidate was William H. Seward of New York. Seward was strongly opposed to slavery anywhere in the U.S. Lincoln took a more moderate view and was opposed to the spread of slavery in new states to the West. 
As Lincoln became more popular in the newly-formed Republican Party he was invited to give speeches in a number of states. In October of 1859, he was invited to speak at Henry Ward Beecher's church in Brooklyn, New York. Lincoln spent months preparing for this speech; more time than he had spent on any speech he had given during the senatorial debates. At the last minute, the site for his speech was moved to the Cooper Union in Manhattan. Lincoln knew why he had been asked to give the address. He was being promoted as an alternative to Seward and other possible Republican candidates. The Cooper Union address got Lincoln the attention he needed to become the Republican candidate for president in 1860. 
In April 1860, the Democrats held their political convention, the Southern Democrats walked out and the convention closed without nominating a candidate. The two sides each held their own conventions two months later. 
Stephen Douglas was the candidate of the Northern Democrats. John C. Breckinridge ran for the Southern Democrats. John Bell, the Senator from Tennessee, ran for the Constitutional Union Party. The split in the Democratic party almost guaranteed Lincoln could win the presidency. At the beginning of 1860, Lincoln was not a major candidate for President. On November6, 1860, with 39% of the popular vote and a majority in the Electoral CollegeWhile the election was held on November 6, 1860 the electors did not meet until December. They sent their sealed ballots to Washington D.C. to be counted. During this time Lincoln did not know for certain he had won the election. A number of things could still go wrong. If the Northern and Southern electors agreed on one of the two Democratic candidates, that candidate might win the electoral vote. Worried over the possibility of secession, Republican electors might choose a different candidate. Then, because of possible secession, there might not be enough electors for a quorum. As it turned out, Lincoln won the majority of electors. Some from the Deep South may have cast votes for Lincoln in order to cause more public support for secession. As Breckinridge was at the time Vice President of the United States and president of the Senate, it was his job to open and read the vote count in February of 1861. However, to prevent any last minute problems, General Winfield Scott placed cannons at the capital. He warned that “any man who attempted by force or unparliamentary disorder to obstruct or interfere with the lawful count” would be “lashed to the muzzle of a twelve-pounder and fired out of a window of the Capitol.” On February 15, 1861, Lincoln was notified he won the presidency., Lincoln was elected President. Voter turnout for the election was 81.2%, the second highest in American history. 
 Secession crisis (1860–1861) 
In November of 1860, with Lincoln the apparent winner, a crisis that had been smoldering for at least a decade erupted. Southerners were outraged by the election of Lincoln, who opposed slavery in territories and new states.More than this, Lincoln and the new Republican-controlled Congress opposed Slave Power. Up to this time in American History, the southern slaveholders had control of the federal government at all levels. By 1850, they had controlled the presidency for 50 years and the Speaker of the House's chair for 41 years. They had controlled the House Ways and Means committee for 42 years. The also controlled great economic power. In 1860, the market value of the South's four million slaves alone was close to $3 billion. The election of Lincoln and the Republicans ended that control. They began to act almost immediately. James Chesnut, Jr., Senator from South Carolina, resigned just four days after the election. President James Buchanan only made things worse. In December, he wrote a message to Congress. In it he stated he thought secession was illegal. But he added that the federal government could not act to stop any states from leaving the Union. Northerners could not understand how Buchanan could say such a thing. After that, Buchanan's cabinet began falling apart. Howell Cobb, the Secretary of the Treasury who was from Georgia, told Buchanan he quit. A week later, Lewis Cass, the Secretary of State (from Michigan) left because Buchanan had done nothing to stop the secession crisis.
South Carolina was the first to take action. Leaders there had warned that if a Republican won the 1868 election, they would leave the Union. On December 20, 1860 in a special convention, they passed a unanimous resolution to secede. In January of 1861 they were followed by Mississippi, Florida, Alabama, Georgia and Louisiana. Texas seceded on February 1. While resolutions for secession were prepared in other states, no more were passed during this period.
While Buchanan did nothing, several senators made speeches in Congress trying to calm things down. The Peace Conference of 1861 was held at the Willard Hotel in Washington on February 4, 1861. Of the 33 states, 21 sent delegates. Former President John Tyler, a native of Virginia, was elected the presiding officer. The convention lasted for about two weeks. During that time a number of proposals were created that were then delivered to Congress. A number of compromises were worked out that would take the form of proposed amendments to the United States Constitution. But none were passed by Congress. At Lincoln's inauguration, he rode in a carriage beside the outgoing president. Buchanan is quoted as saying to Lincoln, "If you are as happy entering the presidency as I am leaving it, then you are a very happy man." Within weeks, four more slave states seceded and the Confederates fired on Fort Sumter.
 First inaugural address 
On March 4, 1861, Lincoln gave his first inaugural address after being sworn in as the 16th President of the United States. The speech was primarily addressed to the people of the South. It was intended to lay out Lincoln's intended policies and desires toward the South where seven states had formed the Confederate States of America. His speech was written in a spirit of friendship toward the seceded states. He touched on several points. Lincoln promised not to interfere with slavery in the states where it already existed. He said there would be no Federal hostility towards the states that had seceded for the time being. The Federal Government would “hold, occupy, and possess” its property. It would also collect its taxes. He closed his speech with the warning: 
 Presidency (1861-1865) 
Lincoln's presidency lasted for about four years. It ran from March 4, 1861 until he was shot by a Confederate sympathizer and died on April 15, 1865. Nearly all of his time in office was consumed by the Civil War. From his election by the Electoral College on February 15 to his inauguration on March 4, Lincoln had little time to assemble a cabinet. 
 Lincoln's cabinet 
Lincoln's cabinet was unique in American history. It included all of his major rivals for the 1860 Republican nomination. As part of the political negotiations leading up to the nomination, some had been promised a position in the cabinet. It was not a harmonious group as most of them did not like each other. They had different ideas about governing the country, different ethics and different personalities. In particular, Simon Cameron,Cameron's reputation for corruption was so bad that Thaddeus Stevens a Pennsylvania congressman, called Cameron a thief during a discussion with Lincoln. But, he added, "I don't think he would steal a red-hot stove". On hearing this, Cameron demanded Stevens take back what he said. Stevens told Lincoln, "I believe I told you he would not steal a red-hot stove. I now take that back." Cameron was Secretary of War for the first year, then he resigned. He could not agree with allowing former black slaves to fight as Union soldiers. He was replaced by his own legal advisor, Edwin Stanton. was forced on Lincoln by a deal struck with the Pennsylvania delegates at the Republican Convention. He already had a reputation for being incompetent and corrupt. Per the agreement he was Lincoln's Secretary of War. 
Members included:
 Hannibal Hamlin, Lincoln's first Vice President (1861–1865).
 Andrew Johnson, Lincoln's second Vice President (1865–1865) and 17th President of the United States.
 Salmon P. Chase, United States Secretary of the Treasury. In 1864 he became Chief Justice of the Supreme Court.
 Simon Cameron, Secretary of War (1861–1862).
 Edwin Stanton, Secretary of War (1862–1865).
 William H. Seward, Secretary of State (1861–1865).
 Gideon Welles, Secretary of the Navy (1861–1865).
 Montgomery Blair, Postmaster General (1861–1864).
 Edward Bates, Attorney General (1861–1864).
 Domestic affairs 
The Lincoln administration found itself tasked with guiding the country through its darkest days. He inherited the problems from his predecessor, President James Buchanan. In his own inaugural address four years earlier, Buchan had called the issues of slavery “happily, a matter of but little practical importance.” Buchanan took the position he did not have the power to do anything about the impending civil war. He said: “It is beyond the power of any president, no matter what may be his own political proclivities, to restore peace and harmony among the states. Wisely limited and restrained as is his power under our Constitution and laws, he alone can accomplish but little for good or for evil on such a momentous question.” As the civil war approached, under Buchanan's presidency the country slid into a recession.
Rather than ignore or accept the situation, Lincoln had to mend a broken nation or see it torn apart. Between the presidential election and his inauguration, the seven states that seceded formed the Confederate States of America. Their constitution was patterned after the United States Constitution with four differences. It supported states' Sovereignty. It guaranteed slavery would always exist in the Confederate states. It did not allow the Southern Congress to establish protective tariffs. It also limited the term of president of the Confederate states to 6 years. Jefferson Davis was elected as president of the CSA. He was a Mississippi slave owner, a U.S. senator and had also been secretary of war under President Franklin Pierce. The CSA assumed several philosophical positions that differed from those of the United States. It assumed the United States was merely an association of sovereign states as they had been under the Articles of Confederation before the acceptance of the U.S. Constitution. They maintained that as such, each state was free to leave the association of states. The North saw the Union as a permanent country. Lincoln pointed out that each state had given up its own sovereignty when it ratified and accepted the Constitution. He also argued that no state had the right to revolt against their country, the United States of America. But Lincoln remained silent about the CSA from their formation until his inauguration. He repeated his campaign promise, that as President he would take no steps to stop or limit slavery in those states where it already existed. However, he did not accept the proposals made by the Peace Commission. Demonstrating his peaceful intentions, his inaugural address was aimed at preventing other Southern states from joining the CSA. They were not enemies. He would not attack the CSA but would keep and maintain all property of the United States government that existed in the Southern states.
A day after his inauguration, Lincoln received a dispatch from Major Robert Anderson. He was the commander of Fort Sumter, in Charleston harbor. He informed Lincoln that if the fort was not resupplied soon, he and his men would have to leave. Lincoln thought of a way to resupply the fort without starting any fighting. He would send unarmed supply ships to Fort Sumter. He informed CSA President Davis of his intentions. This way, the U.S. would not start any fighting but would retain the fort as Lincoln had promised they would. Immediately Davis sent General P. G. T. Beauregard to force the fort's surrender before the supply ships could arrive. At 4:30 a.m. on the morning on April 12, 1861, Confederate guns began a bombardment of Fort Sumter. After 33 hours, Major Anderson surrendered the fort. This was the start of the Civil War.In 1860, no one expected any armed conflict would come from the Southern states secession from the Union. Or, if it did, it would be brief and mostly for show purposes. Southerners did not believe the North would mobilize an army against them. Then, as it became apparent that it would become a military confrontation, both sides believed it would not last very long. In 1861, when the Union Army entered the First Battle of Bull Run, they thought a quick victory would bring an end to the war. After the Union loss at Bull Run, the Confederates thought the Union would simply give up the idea re-uniting the North and South. Both were wrong.
The war lasted for four years. The North did not anticipate the South would fight almost to the last man to defend its "freedom". The South had no idea that the North, led by Lincoln, would show an iron will to preserve the Union at all costs.
 Foreign affairs 
One of Lincoln's military strategies was to blockade the South's ports and approximately 3500 mi of shoreline. At the start of the war, with only a few ships, this was all but impossible. By war's end, the Union had captured or destroyed 1500 blockade runners. But with nearly 5 out of 6 shops able to evade the blockade, Great Britain argued it was not recognized by international law as it was a "paper blockade." The Confederacy was able to ship only a small part of its main cash crop, cotton, to England during the war. Three years before the war the South had shipped 10 million bales of cotton a year. During the war they shipped a total of only 500,000 bales. But English manufacturers had stockpiled large quantities of Southern cotton from the huge exports before the war. What they had on hand carried them through most of the war.
In 1861, both the Confederacy and the Union wanted the help of Great Britain. The North counted on them because of their condemnation of slavery. The Confederacy counted on their help because of the great importance their cotton had to Britain's economy. So both sides had diplomatic relations with Great Britain. The South needed Britain's help to win the war. Also, without the aid of Britain, France would not dare interfere even though they were already friendly with the South. On May 4, 1861, Queen Victoria issued a proclamation declaring Britain's neutrality in the war and recognizing the Confederacy as a belligerent in the conflict. This enraged Lincoln. Seward, his Secretary of State, had already issued instructions to the new minister to Britain to quit and come home should the Queen recognize the Confederacy. France followed with a similar declaration which also recognized the CSA as a nation. Seward warned both nations of the possibility of war with the United States over this issue. 
British Prime Minister Lord Palmerston sent a fleet of naval warships to the western Atlantic in preparation for a surprise attack on New York City. They intended to use the world's largest ship, the SS Great Eastern as a troop transport. They saw a strike against New York would be a strike against the U.S. center of commerce. But in the spring of 1862, the British learned of the Union ironclad warship, the USS Monitor. This cancelled any invasion plans. While the British Navy had ironclad warships, they required deep water to navigate. The Monitor and Northern ships like her could destroy British ships should they try to blockade Northern ports. Russia was also concerned the British and/or French might step in. During the summer of 1862, a coalition of nations considered stepping in to mediate the war. These included Britain, France, Prussia, Austria and Russia. But in the fall of 1863, Tsar Alexander II of Russia sent his navy to protect the United States from any invasion by Great Britain and France. Their Baltic fleet began arriving in New York harbor on September 24, 1863. The Russian Far East fleet was sent to San Francisco.
For the remainder of the war, most European countries had little to gain by recognizing the Confederacy as a sovereign nation. Lincoln was diplomatic in his handling of two Confederates who had been arrested on the British ship the Trent. He ordered them both released. Crop failures in Europe made Union agricultural products popular. Egypt and India were able to supply the cotton that was formerly bought from the South before the war. The Union was also a good customer for small arms and other manufactured goods from Europe. However, dozens of blockade runners and warships were constructed for the Confederate Navy by English shipbuilders during the war. 
 Lincoln as commander in chief 
In 1861, the American Civil war was the first modern total war. And in 1861, nobody in the United States knew how to fight one. Men could be enlisted and war goods could be manufactured, but generals took time to train. The general in chief of the army in 1861 was Winfield Scott, in charge of an army of only about 16,000 men. Scott was both old and old school (meaning he had no modern training). Quite a few officers had been trained at West Point, but at the time West Point taught engineering, mathematics and fortifications. It taught very little about strategy and nothing about leading large formations of soldiers in the field. None had learned anything about staff work or how to manage an army except those few who could read French or who had any military experience in Europe. One of the worst problems is that field commanders did not even have accurate maps of the areas they had to move and fight in. Except in the West, local maps did not exist for many parts of the country. Unlike Jefferson Davis, who did have military experience, Lincoln had almost none.
Lincoln faced a very steep learning curve when the war started. But Lincoln was a quick study. He had taught himself to be a lawyer. Learning military strategy proved to be something else he could do very well. He read books on strategy, military history and learned from the successes and failures of his troops in the field. He also learned from the enemy's military tactics. He learned so well that by 1862, historian T. Harry William said about him: "Lincoln stands out as a great war president, probably the greatest in our history, and a great natural strategist, a better one than any of his generals." Although there is no evidence he ever read Karl von Clausewitz's On War, his actions followed the book's central argument: "The political objective is the goal, war is the means of reaching it, and means can never be considered in isolation from their purpose. Therefore, it is clear that war should never be thought of as something autonomous but always as an instrument of policy."


Chemistry: Chemistry is the science that studies what everything is made of and how it changes. It looks at matter, which is anything that takes up space. Chemistry tries to understand how matter is built, how it behaves, and how it can change. Chemistry explores how tiny particles called atoms and molecules come together, break apart, or rearrange to form new substances. People often call chemistry the “central science” because it connects other sciences like physics (which studies energy and forces) and biology (which studies living things). Chemistry helps explain things all around us, like why iron rusts, how food gives us energy, and how soap cleans our hands.
The history of chemistry is very long. Thousands of years ago, people in places like Mesopotamia, Egypt, India, and China used early forms of chemistry in their daily lives. They practiced metalworking, made dyes for clothes, and learned to ferment food and drinks. These skills were based on watching and experimenting, even though people did not yet understand the science behind them. Later, a practice called alchemy became popular. Alchemists hoped to turn ordinary metals into gold and find a magic liquid that would give eternal life. Even though their ideas were not always scientific, alchemists invented tools and methods that helped future scientists. In the 1600s, chemistry began to change. Scientists like Robert Boyle said that experiments, not just ideas, should be used to understand the world. In the 1700s, Antoine Lavoisier carefully measured chemicals and discovered that matter cannot be created or destroyed, only changed. This became a key idea in modern chemistry. As time went on, scientists developed the atomic theory, created the periodic table, and learned how atoms bond together.
Chemistry is a type of physical science, which means it focuses on understanding matter and how it changes using careful measurements and natural laws. It is closely related to physics, especially in areas like heat and energy (thermodynamics), the behavior of tiny particles (quantum mechanics), and how fast reactions happen (kinetics). These help scientists understand how and why chemical reactions take place. While physics looks for broad, universal rules, chemistry often focuses on how specific molecules and materials behave. Chemists study how atoms come together to form molecules, how energy moves during reactions, and how things like temperature, pressure, and the amount of each substance can affect the speed of a reaction. Using tools and models, chemistry helps us explore both the tiny world of atoms and the larger world of solids, liquids, gases, and plasma. It plays a big role in helping us understand the materials that make up everything around us.
Chemistry is very important in both science and everyday life. It plays a big role in many areas, like medicine, farming, energy, and making new materials. You can find chemistry in everything from the food you eat to the soap you use and the medicine you take when you are sick. Thanks to chemistry, we have clean water, solar panels, plastic, and life-saving drugs. It helps explain everyday things, like why bread rises when you bake it, how soap gets rid of grease, and what happens when your body digests food. Chemists also study pollution, look for better ways to protect the environment, and create new materials that are safer and better for the planet. As the world faces problems like climate change, diseases, and limited resources, chemistry helps us find smart and useful solutions.
Chemistry is not a subject that stands alone. It is closely connected to many other sciences. Chemistry and physics are closely linked because the movement of atoms, energy, and tiny particles like electrons all follow the laws of physics. In biology, chemistry helps us understand how living things work. It explains how enzymes speed up reactions in the body, how DNA carries genetic information, and how cells turn food into energy. This area of science is called biochemistry. In geology, chemistry helps us learn what rocks and minerals are made of, how volcanoes work, and how elements move through Earth’s surface, oceans, and air. Chemistry is also important in environmental science, astronomy, engineering, and making new materials. Because of these connections, chemistry is one of the most important and wide-reaching sciences.
History
Prehistoric Chemistry
In prehistoric times, chemistry was not a real science like it is today. Instead, it was more like a mix of practical skills and simple observations that helped people survive. Early humans learned how to use the materials around them by trying things out and watching what happened. Over time, they began to understand how some things changed. This hands-on experience helped them slowly build a basic understanding of chemical changes, even though they did not know the science behind it. One of the most important achievements of early humans was learning how to control fire. Cooking was one of the most important uses of fire. It made food taste better and easier to digest. Cooking also helped kill germs, which made food safer to eat, especially meat. Since early humans did not have refrigerators, cooking helped food last longer and reduced the chance of getting sick from spoiled or raw meat. Fire was also used for other important tasks. For example, early people discovered that heating the tips of wooden tools made them harder and stronger. They also learned to shape wet clay into pots and bowls, then bake them in fire to make them tough and long-lasting.
By around 5000 BCE, people began to discover a new use for fire, making metal from rocks. This early process was called smelting. It marked the beginning of metallurgy, the science of working with metals. Before this, people mostly used native metals, which are found in nature in pure form, like small lumps of gold or copper. But now, they learned how to get copper out of rocks called ores, such as malachite or azurite. To smelt copper, they had to heat the ore in a very hot fire, hot enough to melt the metal and separate it from the rock. This was not easy. It required skill in building and controlling fire. Sometimes they used tools like bellows to blow air and make the fire hotter. They also had to choose the right rocks and other materials to help the process work better. The result was soft copper, which could be shaped into tools, weapons, and jewelry.
One of the earliest examples of prehistoric chemistry was using natural pigments for cave paintings. People ground up minerals like ochre (which is made of iron oxide), charcoal (which is made of carbon), and manganese dioxide into powders. They mixed these powders with animal fat or water to make paint. People used these paints for rock art and decorating their bodies. Another important skill was tanning hides. This meant soaking animal skins in plants with tannins, like tree bark. This process made the leather last longer, stay flexible, and be useful for making clothes or tools. Fermentation also started during this time. At first, it probably happened by accident when fruit or grains went sour. As early as 7000 BCE, people in China were mixing rice, honey, and fruit to make a kind of early alcoholic drink. At the same time, people in Mesopotamia and Egypt were learning how to brew beer and make bread rise by fermenting dough. These processes used wild yeasts and bacteria to turn sugars into alcohol or carbon dioxide, which changed the taste and texture of the food. Even though they did not know about microorganisms, early humans figured out how to make fermentation work.
Metals like gold, silver, and copper became very special. Gold was rare, shiny and beautiful, and also did not get dull or rust, so it was used for ceremonies and to show status. Silver was shiny and easy to shape, so it was used for jewelry and everyday items. Copper was valuable because it could be made into tools and weapons. People started mining these metals on purpose and trading them. One of the biggest discoveries was mixing copper with tin to make bronze. Bronze was first made about 3300 BCE, during the time between the late Stone Age and the early Bronze Age. The oldest proof of making bronze comes from Mesopotamia, an area that is now Iraq and parts of Syria and Turkey. People there started mixing copper with tin to make a metal that was stronger and lasted longer. This new way of making metal eventually spread to other places like the ancient Near East, Europe, and the Indus Valley. Bronze was stronger and harder than tin or copper alone. This was one of the first times people made a new material on purpose by combining substances. Bronze tools and weapons helped societies grow, build cities, and create professional armies.
Salt was one of the most important chemical substances in early civilization. It was not just used to add flavor to food. It helped people keep meat and fish from spoiling, so they could store food for a long time. This made it possible to travel farther, plan for different seasons, and build towns away from places with fresh food. Because salt was so useful, it became very valuable and was traded over long distances. Some trade routes and even early cities grew around places where salt was found, and in some cultures, salt was even used as money.
Ancient Chemistry
In ancient civilizations, chemistry started to become more organized and intentional. Unlike the earlier times when people learned mostly by guessing and trying things out, ancient cultures began to keep records and follow steps more carefully. Even though they did not know about atoms or molecules, they still learned how to change and use natural materials in useful ways. Civilizations like ancient Egypt, Mesopotamia, India, China, and Greece all made important contributions. They used chemistry for everyday needs like making metal tools, preserving food, and creating medicines. They also used it for spiritual or religious reasons, such as preparing bodies for burial (embalming), making perfumes, or using special materials in ceremonies. These cultures wrote down their ideas and methods on things like clay tablets and scrolls. This helped them improve their techniques and pass knowledge down to future generations.
In ancient Egypt, chemistry was closely connected to religion, medicine, and daily life. The Egyptians were skilled at using natural materials like minerals, dyes, and plant resins, especially when it came to preserving bodies for the afterlife. They used a special salt mixture called natron, made of natural chemicals like baking soda and salt, to dry out dead bodies and prevent decay. They also added oils, herbs, and resins to stop bad smells and protect the body. Egyptians were also talented metalworkers. They knew how to melt down copper ores like malachite in hot furnaces using charcoal to get pure metal. They used metals like gold, copper, and lead to make tools, jewelry, and statues. They also made green eye paint from malachite and black eyeliner (kohl) from a mineral called galena (lead sulfide). These were not just for beauty. They were believed to help protect their eyes from infections and bright sunlight. Egyptians also made perfumes and scented oils by mixing plant parts, resins, and fats. They used early versions of extraction methods, like soaking flowers in oils or using heat. Some even think they may have used very simple distillation to collect scents. One of their greatest chemical achievements was glass-making. As early as 1500 BCE, they were making colorful glass beads and jars using a mix of sand (silica), soda (a type of salt), and lime, all melted together in hot ovens. By adding different metals, they could change the color. Copper made blue, iron made green, and manganese made purple. Chemistry also played a role in Egyptian medicine. Ancient texts like the Ebers Papyrus included hundreds of recipes for medicines made from minerals, herbs, and animal parts. Some treatments were based on beliefs and rituals, but many were surprisingly accurate and showed real knowledge of how the human body reacted to certain substances.
In Mesopotamia, especially in places like Sumer and Babylon, people made important early discoveries in chemistry, mostly through practical work. They wrote down their knowledge on clay tablets using a writing system called cuneiform. These records show in detail how they used different materials. One of their biggest contributions was in metalworking. The Sumerians and Babylonians learned how to get metals like copper, tin, lead, silver, and gold from rocks called ores. They built furnaces hot enough to melt these ores. By mixing copper and tin, they created bronze, a strong metal used for making tools, weapons, and art. This marked the start of the Bronze Age. Pottery and ceramics were also important. They used kilns (hot ovens) to bake clay and to make glazes, which gave pottery shiny, colorful finishes. These glazes were made by mixing minerals and metal powders like copper or iron, which changed color when heated. Pottery was used in homes, temples, and for special objects. Mesopotamians also made progress in perfume-making. Ancient clay tablets from cities like Mari and Babylon describe how they got scents from plants, spices, and tree resins. They may have used early versions of distillation, heating ingredients and collecting the vapor to concentrate smells. These perfumes were used in religious ceremonies, for personal grooming, and sometimes in medicine. In medicine, Mesopotamian healers called asu (practical doctors) and ashipu (spiritual healers) made remedies by mixing minerals, herbs, and animal parts. Some ingredients, like sulfur, salts, and alkalis, had real chemical effects. Their treatments, written on Assyrian tablets, included directions for curing fevers, wounds, and stomach problems, often with both practical steps and magical prayers. Another interesting substance they used was bitumen, a sticky, black natural material similar to modern asphalt. They used it for building, waterproofing, and even to preserve bodies like in mummification.
In ancient India, people had a deep and detailed knowledge of chemistry, especially in medicine and spiritual practices. This knowledge was recorded in early texts like the Vedas and Ayurvedic writings. One major area of chemical knowledge was Ayurveda, the traditional Indian system of medicine. Ayurvedic healers used herbs, minerals, and even animal products to make medicines that matched each person’s body type, known as a dosha. These healers used careful steps like heating, grinding, and washing to prepare them. For example, they used mercury (called rasa) in special medicines called rasaushadhis, often mixing it with sulfur. Ancient Indian alchemy, called Rasayana Shastra, also played a big role. While it had mystical goals like living longer or turning base metals into gold, it led to real scientific progress. They used early chemical techniques like calcination (marana), distillation (patan), sublimation (sublimna), and fermentation (sandhana). They built and used tools such as yantras (distillers), musha (crucibles), and retorts (curved tubes), often made from clay or metal. Metallurgy, the science of working with metals, was another area where ancient India stood out. Indian blacksmiths were some of the first to smelt iron, and by the first millennium BCE, they had invented a special kind of strong steel called Wootz steel. This steel was famous for its strength and was traded all over the world. A great example of their skill is the Iron pillar of Delhi, built around the 4th century CE, which has not rusted much even after 1,600 years. India was also among the first cultures to extract and purify zinc. They worked with metals like gold, silver, copper, and lead. In daily life, Indian chemistry showed up in dyeing, cosmetics, and perfumery. Artisans made colorful dyes from plants and minerals for clothes and art. They made perfumes and incense by collecting scented oils from flowers and herbs using early forms of distillation. These recipes and tools were written down in books like the Brihat Samhita, which explained not just what to use, but how to prepare each substance step by step.
In ancient China, chemistry was closely connected to Taoist beliefs and natural ideas, especially the concepts of yin and yang and the Five Elements: wood, fire, earth, metal, and water. These ideas helped guide how people thought substances changed and interacted with each other. One of the most important parts of Chinese chemistry was alchemy, “the way of the elixir”. Alchemists tried to create special elixirs, magical mixtures that they believed could bring immortality or spiritual powers. They used materials like mercury, sulfur, arsenic, and other minerals and metals. While some of these elixirs were dangerous or poisonous, the work led to better knowledge of how different substances behaved and reacted. For example, Chinese alchemists learned how to heat cinnabar (a mercury mineral) to get liquid mercury. These experiments accidentally led to one of the greatest discoveries in chemistry: gunpowder. Around the time of the Tang Dynasty (7th–10th century CE), Taoist alchemists trying to make an elixir of life mixed sulfur, saltpeter, and charcoal, and instead discovered an explosive powder, gunpowder. This changed warfare forever and eventually spread around the world. The recipe was written down in military books like the Wujing Zongyao (written in 1044 CE). Besides alchemy and gunpowder, the Chinese were also masters of metallurgy. Long before Europe, they had created blast furnaces to make cast iron. They developed strong metal mixtures like bronze (copper and tin) and even steel. These metal tools and weapons helped China grow and succeed. Ancient China also developed medicine. Books like the Shennong Bencao Jing (written around the 1st century CE) listed hundreds of plants, minerals, and animal parts used to treat illness. Medicines were made using chemical techniques like grinding, boiling, fermenting, and roasting. Doctors noticed how different amounts, preparation styles, and combinations of ingredients affected the body, even though they explained it using traditional ideas like qi (life energy) and balance between organs. Finally, ancient Chinese people were experts in ceramics, dyeing, and glass-making. The art of making porcelain used special clay (kaolinite) and very high firing temperatures in kilns. They carefully controlled the heat and mixed minerals to make beautiful glazes. Chinese artists also used metal powders to make colorful finishes, like cobalt for blue, copper for green, and iron for brown or black.
Classical Theories of Matter
In the history of chemistry, classical theories of matter were the early ideas people had about what everything is made of and how it changes. These ideas came from ancient civilizations long before scientists understood atoms like we do today. Even though these early theories did not use experiments like modern chemistry, they helped people start thinking about the nature and structure of matter. These ideas set the stage for many important discoveries later in chemistry.
In ancient Greece, people had different ideas about what matter was made of. One early idea came from Empedocles in the 5th century BCE. He said all matter was made of four basic elements: earth, water, air, and fire. These elements could mix and change because of two forces: love (which brings things together) and strife (which pulls things apart). Later, Aristotle added a fifth element called aether, which he believed made up the sky and stars. He also linked the four elements to qualities like hot, cold, wet, and dry, which helped explain how matter could change. Another important idea came from Democritus and his teacher Leucippus. They said that everything was made of tiny, unbreakable particles called atoms. These atoms were different in shape and size, and how they combined created all the different materials around us. Even though they did not have experiments to prove it, this idea was very similar to what scientists believe today and was very different from Aristotle’s ideas.
In ancient India, there was an idea similar to atoms in a school of thought called Vaisheshika, started by a thinker named Kanada around the 2nd century BCE. They believed that everything is made of tiny, unbreakable particles called “anu” or “paramanu.” These particles combine in different ways to make all kinds of materials. They also created a way to group things based on qualities like taste, color, and how they feel. Even though their ideas were mixed with philosophy and spirituality, they were trying to explain how things change and why there are so many different materials. At the same time, in ancient China, people explained matter using the ideas of yin and yang and the Five Elements (called Wu Xing): wood, fire, earth, metal, and water. These were not elements like we think of them today but were seen as phases or processes that energy goes through. Each element had connections to different qualities, directions, body organs, and natural events. This system helped explain things like nature’s cycles, health, and balance in society, and it influenced Chinese medicine, alchemy, and ideas about the universe for many centuries.
Medieval Chemistry
During the medieval period (about the 5th to 15th century AD), chemistry was not yet a formal science like it is today. Instead, it was mixed with hands-on crafts, spiritual beliefs, and ideas passed down from ancient times. This period was like a bridge between ancient alchemy and the modern science of chemistry that would come later. People during this time used chemical knowledge in many parts of daily life. For example, medicine used herbal mixtures, metal-based compounds, and special liquids called elixirs to treat sickness. These were made through experiments and trial-and-error methods. Metalworking, or metallurgy, was also important. Craftsmen learned how to extract metals like iron, copper, tin, and lead from ores. They used fire and special tools to melt and combine metals, which involved real chemical changes like smelting and making alloys. Other industries like glassmaking and dyeing cloth also depended on chemistry. Workers learned how heat, minerals, and plants could change color or texture. Even though they did not fully understand why it worked, they gained skills and passed them on through guilds and workshops. This time in history helped keep old knowledge alive and slowly improved it, setting the stage for the science of chemistry to grow in the future.
During the medieval period, the Islamic world became one of the most advanced places for chemical knowledge and learning. After the fall of the Western Roman Empire, the Islamic Golden Age (from the 8th to the 14th century) saw a great effort to collect and build upon the science of earlier civilizations. Scholars in cities like Baghdad, Cairo, and Cordoba translated important books from Greek, Persian, and Indian languages into Arabic. But they did not just copy old ideas, they improved them. One famous scientist, Jabir ibn Hayyan (known in Europe as Geber), is often called the “father of Arab chemistry.” He wrote hundreds of books describing different substances and how they reacted with each other. He also created new ways to study materials using experiments. Jabir worked with processes like distillation, crystallization, and calcination. He even helped design tools like alembics and retorts, which were used in early chemistry labs. Jabir tried to understand matter by observing its properties, like how easily it burns or changes. Even though his ideas were influenced by alchemy and religious beliefs, he took important steps toward using experiments to test ideas. His work also introduced many Arabic words for chemicals and tools that later became part of European chemistry. Other Islamic scholars, like Abu Bakr al-Razi (Rhazes) and Al-Tughra'i, continued to build on Jabir’s work. Al-Razi was especially important in medicine. He made antiseptics, acids, and cures for different illnesses. He was also one of the first people to tell the difference between trying to turn metals into gold (a common alchemical goal) and doing useful science to understand how materials behave. These Islamic chemists helped create important tools and methods that were later shared with European scientists. Their books were translated into Latin in places like Sicily and Spain, allowing European scholars to learn from their experiments. This knowledge helped Europe begin its own journey toward modern chemistry.
In medieval Europe, alchemy was shaped by a mix of ancient ideas, Christian beliefs, and mystical thinking. European alchemists believed that changing metals was not just about science, it also had a spiritual meaning. For them, turning ordinary metals into gold was a symbol of purifying the soul and reaching a higher, more perfect state. One of their main goals was to create the Philosopher’s stone, a magical substance they thought could change metals into gold and even give eternal life. Even though alchemy was full of spiritual ideas, it also led to real scientific progress. Important European alchemists like Roger Bacon, Albertus Magnus, and Raymond Lull helped connect mystical ideas with careful observation and early experiments. Roger Bacon, a monk, believed that learning through experiments was important and studied things like light and materials. Albertus Magnus wrote a lot about minerals and metals and helped organize what people knew about them. Raymond Lull used symbols to explain complex ideas, and some of his systems were later used to describe chemical reactions.
During the Middle Ages, the translation of books played a big role in helping chemistry grow in Europe. As Europeans came into more contact with the Islamic world, through trade, the Crusades, and the reconquest of Spain, they discovered many scientific texts written in Arabic. These included both translations of ancient Greek writings and original works by Muslim scientists. Cities like Toledo in Spain and Palermo in Italy became important places where scholars translated Arabic texts into Latin. Thanks to this, the ideas of famous Islamic chemists like Jabir ibn Hayyan and Abu Bakr al-Razi became known across Europe. Their work helped inspire European scientists and planted the seeds for future experiments. At the same time, monasteries in Europe were important for keeping and sharing knowledge. Even though monks mainly focused on religion, they also worked on tasks that used chemical skills. For example, making fancy books called illuminated manuscripts required knowledge about how to make colorful inks from minerals and plants. Monks also brewed beer, made wine, preserved food, and prepared herbal medicines. These activities were based on chemical knowledge, even if the monks did not call it “chemistry.” Craft workers in cities also helped chemistry grow through hands-on work. People like blacksmiths, potters, glassmakers, tanners, dyers, and brewers learned how to change raw materials into useful things. They melted metals, made shiny glazes for pottery, created dyes from plants and bugs, and controlled how things fermented. These workers learned by doing, often as apprentices in guilds. Even though they were not scientists, they used chemistry in their everyday jobs and passed their knowledge down through generations.
By the late Middle Ages, as Europe moved into the early modern period, alchemy started to change. People were becoming less interested in trying to make gold or find ways to live forever, because those goals rarely worked. Instead, more people began to focus on real results. Things they could see, test, and use in everyday life. One important thinker during this time was Paracelsus, a doctor in the 1500s. He believed that alchemy should be used to help people, especially in medicine. He used minerals like mercury, arsenic, and antimony in treatments, substances that were usually feared. Paracelsus is famous for saying, "The dose makes the poison," which means that even dangerous substances can be helpful if used in the right amount. This idea became an important rule in medicine and toxicology. Paracelsus also believed that people should learn about nature by observing and experimenting, not just by reading old books. He studied how chemicals reacted and how they affected the human body. This helped move chemistry away from mystical ideas and closer to real science. Another key figure was Andreas Libavius, a German doctor and chemist. He believed that knowledge should be shared clearly and openly. In 1597, he wrote Alchemia, one of the first chemistry textbooks. In it, he explained tools, techniques, and substances in a simple and organized way. This was very different from the secret codes and symbols used by older alchemists.
The Birth of Chemistry
The birth of classical chemistry in the 1500s and 1600s was a big turning point. During this time, chemistry began to move away from the old mystical ideas of alchemy and become a more careful, scientific way of understanding the world. This change happened during the Scientific Revolution, a time when people started to focus more on observing nature, doing experiments, and thinking for themselves instead of just trusting old books and beliefs. Classical chemistry did not appear overnight. It grew slowly as scientists developed better ways to test ideas, improved their lab tools, and began to think differently about matter and how it changes. One important change was that scientists started to question the old idea that everything was made of four or five elements, like earth, water, fire, and air. Instead, they looked more closely at how substances were made and how they reacted in real-life experiments. This new way of thinking helped turn chemistry into a true science, based on facts, testing, and clear thinking.
Robert Boyle was an important figure in the history of chemistry. His book The Sceptical Chymist, published in 1661, is often seen as the moment when chemistry started to move away from old alchemical ideas and become a true science. He challenged long-held beliefs about what matter is made of and how it changes. At the time, many people still believed in the old idea that everything was made of four elements: earth, air, fire, and water. Boyle disagreed. Instead, he suggested that all matter is made of tiny particles, which he called "corpuscles." These particles could combine in different ways to form all the materials in the world. This idea was an early step toward what we now call atomic theory. One of Boyle’s biggest contributions was his new definition of a chemical element. He said an element is a substance that cannot be broken down into anything simpler by chemical methods. Even though he did not know about all the elements we recognize today, his definition helped future scientists, like Antoine Lavoisier, build a better system for understanding them. Boyle was also a strong supporter of careful, repeatable experiments. He believed scientists should write down exactly what they did and what happened, so others could try the same experiments and check the results. This idea of clear, honest reporting is a key part of how science works today. Unlike many alchemists who kept their findings secret, Boyle wanted to share knowledge. He helped start the Royal Society of London, a group that encouraged scientists to share ideas and discoveries openly.
During the 1500s and 1600s, as chemistry was changing, the tools and techniques used in the laboratory improved a lot. Old alchemical tools like retorts, alembics, crucibles, and furnaces were still used, but they were made better. A retort was often made of glass and metal. It was used to heat liquids and collect their vapors, and helped scientists separate parts of a mixture by heating it. An alembic was another tool that helped separate and cool down gases, turning them back into liquids. Over time, alembics were made with better seals and more consistent shapes so they worked better and gave more reliable results. Crucibles were small containers used to heat materials to very high temperatures. They were often made from strong ceramics that could handle the heat and be used many times, which was especially important when working with metals and minerals. Many chemical processes were also becoming clearer and more organized. For example, distillation was used to purify substances like alcohol or perfumes. Filtration was used to separate solid bits from liquids using cloth, paper, or fine mesh. Precipitation meant making a solid appear out of a liquid by mixing certain chemicals, useful for finding out how different substances react. Crystallization helped scientists purify salts and study the shapes of crystals. Glassmaking became very important too. In places like Venice and other parts of Europe, people learned to make clear, heat-resistant glass. This allowed scientists to see what was happening inside their experiments. Tools like flasks, beakers, funnels, test tubes, and condensers became more uniform, meaning they looked and worked the same in different labs. This made it easier for scientists to copy each other’s work and learn together. New measuring tools also made a big difference. Scientists started using balances (scales) that were more sensitive, which helped them measure materials more accurately. This led to the early idea that the total amount of matter stays the same during a reaction, a key idea in modern chemistry. Thermometers, improved by people like Galileo, let scientists track temperature changes during experiments. With better tools and more exact methods, chemistry became less about guessing and more about testing, recording, and sharing results.
In the world of medicine, a new idea called iatrochemistry began to change how people thought about health and healing. Iatrochemistry combined chemistry with medicine and was based on the bold ideas of a scientist named Paracelsus. At the time, most doctors believed in humoral theory, which said sickness came from imbalances in body fluids. But Paracelsus disagreed. He believed that diseases came from outside the body or from chemical problems inside it, and that they should be treated with chemical medicines, not just herbs or bloodletting. Paracelsus introduced the idea of using minerals and man-made substances to treat illnesses. This opened the door to pharmacology, the science of making and testing medicines. By the 1600s, doctors and chemists started working together more closely. They tested materials like antimony, mercury, arsenic, and different salts and tinctures to see if they could cure diseases. Some of these early treatments were harmful or did not work well, but the process of testing, observing, and improving them helped medicine become more scientific. Apothecaries and early pharmacy labs became important places where these treatments were studied and made. At the same time, growing industries in Europe helped chemistry move forward in other ways. As people needed more metals, dyes, ceramics, textiles, and glass, workers had to learn more about how materials changed and reacted. For example, mining and metalwork required people to understand how to find and melt metal ores, how to mix metals into alloys, and how to deal with waste. These jobs needed a good understanding of heat and chemical reactions, so chemists began studying materials more carefully. In the textile and dye industries, creating bright, long-lasting colors for fabrics took a lot of experimenting. Workers used substances like alum, indigo, madder, and cochineal (a red dye made from insects) and had to figure out how to make the colors stick to the cloth. Glassmakers and potters also used chemistry to improve their crafts. They learned to mix silica, soda, and lime in just the right amounts to make clear or colorful glass. By adding small amounts of metals like cobalt for blue, copper for green, or gold for red, they could make beautiful glassware. In trying to copy Chinese porcelain, European makers studied how clays and glazes behaved when heated in kilns, leading to more discoveries in chemistry.
One of the most important changes in science during the 1600s was the creation of scientific societies. These were groups where scientists could meet, share their work, and learn from each other. One of the first and most famous of these groups was the Royal Society of London, founded in 1660. It brought together people like doctors, inventors, and scientists who were all interested in studying nature in a careful, organized way. The Royal Society had a special motto: "Nullius in verba," which means "take nobody’s word for it." This meant they believed in evidence and experiments, not just trusting old books or famous people. Scientists had to prove their ideas through testing and clear results. This approach was a big step forward in turning chemistry into a serious science. Similar groups started in other countries too. In France, the Académie des Sciences was created in 1666. These societies gave chemistry a new home in public places where experiments could be watched, repeated, and discussed by others. Scientists now had places to show their work, get feedback, and improve their ideas based on what others had done. Another big change was the rise of scientific journals. These were like magazines for scientists to publish their discoveries. The Royal Society started one of the first, called Philosophical Transactions of the Royal Society, in 1665. It helped chemists share their methods, tools, and results with other scientists across Europe. This helped science move faster because others could repeat experiments, test new ideas, or improve old ones. Books like Physica Subterranea by Johann Joachim Becher and writings by Georg Ernst Stahl (who supported the phlogiston theory) showed how print helped scientists share and debate their ideas, even when they did not agree. In addition to books and journals, letters were very important. Scientists like Robert Boyle, Antoine Lavoisier, Isaac Newton, and Robert Hooke often wrote to each other, sharing drawings, experiments, and new ideas. These letters helped build an international community of scientists, even before the internet or telephones existed. At first, chemistry was not seen as important as math or physics. Some people thought it was too close to the strange ideas of alchemy. But chemistry began to earn respect because it was useful and connected to the Age of Enlightenment, a time when people believed in reason, progress, and discovery. Slowly, universities began teaching chemistry, and students got to learn in real labs, not just from books. This helped turn chemistry into a respected professional science, just like it is today.
The Chemical Revolution
At the start of the 18th century, chemistry still relied on old ideas from alchemy and natural philosophy. One of the most famous ideas was the phlogiston theory, first created by Johann Joachim Becher and later improved by Georg Ernst Stahl. This theory said that all things that could burn had a special substance called phlogiston inside them. Phlogiston was thought to be invisible and weightless, and was released when something burned. According to the phlogiston theory, when a material burned or when metal rusted, it was losing phlogiston into the air. For example, when wood turned into ash or iron became rust, people believed the phlogiston left the material, and what was left behind was called “dephlogisticated.” This idea also tried to explain other things, like how animals breathe, thinking that breathing was the slow release of phlogiston from the body. The phlogiston theory seemed to explain many observations about fire and burning, so it became very popular in European chemistry for many years. However, no one could ever find or measure phlogiston directly. Scientists could not isolate it or prove it was real. Sometimes they had to change the idea to fit what they saw. For example, when metals actually gained weight after burning, they said phlogiston had "negative weight," which did not make sense.
One of the biggest changes in 18th-century chemistry was the rise of pneumatic chemistry, which is the study of gases and their properties. Chemists like Stephen Hales helped start pneumatic chemistry by inventing special tools to catch and measure gases. He used a method to collect gases over water, which let scientists isolate different kinds of “airs” (what people called gases back then). This was a big deal because it gave chemists a way to study gases carefully and learn how they acted. Building on this work, Joseph Black made an important discovery with a gas called carbon dioxide, which he called “fixed air.” Black showed that fixed air was different from normal air. He found that this gas could put out flames and that it reacted with limewater to make a solid. These tests proved that fixed air had its own special chemical properties. Black’s discovery showed that air was not just one thing but a mix of different gases.
The study of gases led to many important discoveries. Henry Cavendish found hydrogen, which he called “inflammable air” because it burned easily with a pale blue flame. Cavendish also showed that when hydrogen burns, it combines with oxygen to make water. This was a big surprise because people used to think water was a basic element. Cavendish proved that water is actually made of two gases, which changed how scientists understood chemistry. At the same time, two chemists, Joseph Priestley and Carl Wilhelm Scheele, both discovered oxygen. They found this gas independently, but Priestley was the first to publish his results. He called it “dephlogisticated air” because he believed in the phlogiston theory, thinking oxygen was air that had lost something called phlogiston. Scheele probably found oxygen first but published later. He described oxygen’s strong ability to help things burn and support breathing, though he also still believed in the old phlogiston ideas. Even though their ideas about phlogiston were wrong, these discoveries of oxygen, hydrogen, and carbon dioxide changed chemistry forever. These findings helped lead to the end of the phlogiston theory and the start of modern chemistry.
Even though scientists had made big discoveries about gases and started to question the phlogiston theory, it was a French chemist named Antoine-Laurent de Lavoisier who finally proved the theory wrong and helped create modern chemistry. Lavoisier showed that burning and breathing were not about releasing an invisible substance called phlogiston. Instead, these were chemical reactions where things combined with oxygen, which is a part of air. Lavoisier did careful experiments where he weighed things before and after chemical reactions. He found out that the total weight stayed the same, even though the substances changed. This idea is called the conservation of mass, meaning matter cannot be made or destroyed, only changed into something new. This was a brand-new way of thinking that went against the old phlogiston ideas.
Besides his important experiments, Lavoisier knew it was necessary to have a clear and simple way to name chemicals. Before his work, chemical names were confusing because the same substance could have different names in different places. In 1787, Lavoisier and his helpers, like Berthollet and Guyton de Morveau, created a system to name chemicals based on what they were made of and their properties. This made it easier for scientists to talk and work together. In 1789, Lavoisier published a famous book called Traité Élémentaire de Chimie. This book is considered the first modern chemistry textbook. In it, he clearly explained what chemical elements are, substances that cannot be broken down into simpler parts by chemical means. He also listed many elements known at the time, such as oxygen, hydrogen, nitrogen, and some metals. This helped create the idea of elements that chemists still use today. Lavoisier’s work also led to a new way of studying chemistry called stoichiometry. This means understanding the exact amounts of substances used and produced in chemical reactions. He introduced balanced chemical equations that showed these reactions in symbols and numbers. Because of this, chemistry became a science based on measurements and math, making it easier to predict and repeat experiments.
The Rise of Modern Chemistry
In the 19th century, a big change in chemistry was the development of atomic theory by John Dalton, an English teacher and chemist. In 1803, Dalton said that everything is made of tiny, invisible particles called atoms. Each element is made of its own kind of atom, and each kind has a specific weight. Dalton’s idea was based on careful observations and experiments. He also explained that atoms combine in simple, whole-number amounts to form compounds. This helped explain why compounds always have the same kinds of atoms in the same amounts. For example, carbon and oxygen make two different compounds: carbon monoxide (CO) and carbon dioxide (CO₂). In these compounds, the amount of oxygen compared to carbon is always in simple ratios like 1 to 2. Dalton’s work supported the idea that matter is made of small, separate particles. He even made one of the first lists of atomic weights, comparing everything to the weight of hydrogen atoms. Dalton also used special symbols to stand for atoms and molecules, which later became the chemical symbols we use today.
In the 19th century, there was a big change in how scientists understood organic chemistry. For a long time, people believed in something called vitalism. This was the idea that organic compounds, chemicals found in living things, could only be made by living organisms because of a special "vital force." They thought these compounds could not be made in a lab. But in 1828, a German chemist named Friedrich Wöhler did an important experiment that changed everything. He heated a simple chemical called ammonium cyanate, which is inorganic (not made by living things), and it turned into urea, a compound found in the urine of living organisms. This showed that organic compounds could be made in the lab without any living organism involved. Wöhler’s discovery opened the door for scientists to study and create many more organic compounds. Chemists started working with a wide range of carbon-based substances like alcohols, acids, dyes, and medicines. One important result of Wöhler’s work was a new focus on chemical structure. Scientists discovered that certain groups of atoms, called functional groups, determine how molecules behave. Chemists like Justus von Liebig and August Kekulé helped develop ideas about how atoms bond together in molecules. Kekulé, for example, suggested the famous ring shape of the benzene molecule in 1865.
In the 1800s, one of the biggest breakthroughs in chemistry came from a Russian scientist named Dmitri Mendeleev. In 1869, Mendeleev created the periodic table which completely changed how scientists understood the building blocks of matter. At that time, about 63 elements were known, but they seemed like a random list with no clear pattern. Mendeleev had a smart idea. He arranged the elements in rows and columns based on their atomic weights and how they reacted chemically. When he did this, he noticed a repeating pattern in their properties. He called this the “periodic law”. What made his table special was that he left blank spaces where he thought unknown elements would one day fit. He even predicted what these missing elements would be like, what their atomic weights would be and how they would behave. Later, scientists discovered elements like germanium, scandium, and gallium, and they turned out to be almost exactly as Mendeleev had predicted.
In the 1800s, chemistry made big leaps forward, especially in the areas of analysis and energy. One of the most exciting new tools was spectroscopy, which was developed in the 1850s by two scientists named Robert Bunsen and Gustav Kirchhoff. They discovered that when elements are heated or excited, they give off light in unique patterns, like fingerprints. These patterns, called spectral lines, helped scientists identify which elements were present in a substance just by looking at the light it gave off. Using this new technique, Bunsen and Kirchhoff found two new elements, cesium in 1860 and rubidium in 1861, by their special spectral lines. Spectroscopy did not just help on Earth; it also helped scientists study stars. By looking at the light from stars, they could figure out what elements the stars were made of, even from millions of miles away. Spectroscopy started helping astronomers in the early 1800s. Scientists noticed that when sunlight passed through a special glass called a prism, it created a rainbow of colors, but with some dark lines missing. In 1802, W. H. Wollaston saw these dark lines, and in 1815, Joseph von Fraunhofer studied them more closely. These dark lines were called absorption lines, and they were very important. They showed that certain colors of light were being absorbed by gases in the Sun’s outer layers. This gave scientists their first clues about what the Sun was made of. Later, the same method helped astronomers figure out the chemical makeup of other stars, too. At the same time, chemists were also learning more about how energy works in chemical reactions. A scientist named Germain Hess came up with Hess’s Law, which says that the total energy change in a chemical reaction is the same, no matter how many steps it takes. Later, James Prescott Joule made another big discovery. He showed that heat and mechanical energy (like moving parts) are really just different forms of the same thing. His famous experiment with a paddle wheel helped prove this. These ideas became part of the first law of thermodynamics, which says that energy cannot be created or destroyed, it can only change form.
The Industrial Revolution in the 1800s brought big changes to the world, and chemistry played a major role in making that happen. One of the biggest breakthroughs was in steelmaking. In the 1850s, Henry Bessemer invented a process to turn melted iron into strong steel by blowing air through it to remove unwanted materials. This Bessemer process made steel much cheaper and easier to produce. As a result, steel was used to build railroads, ships, bridges, and buildings all over the world. At the same time, chemistry helped create synthetic dyes. In 1856, a young chemist named William Henry Perkin was trying to make medicine but accidentally created a bright purple dye called mauveine. This dye was the first of its kind and made colorful clothing affordable for many people. Perkin’s discovery started a new industry, and soon many companies were making different kinds of synthetic dyes for clothes and fabrics. Explosives were another area where chemistry made a big impact. Chemists like Ascanio Sobrero and Alfred Nobel developed powerful materials such as nitroglycerin and dynamite. These explosives were used in mining, building tunnels, and even in war. Nobel’s inventions made blasting safer and more effective. He later created the Nobel Prizes to honor great achievements in science and other fields. Chemistry also helped farmers by improving fertilizers. Scientists like Justus von Liebig discovered that plants need certain minerals to grow well. This led to the creation of artificial fertilizers like superphosphates and ammonium salts, which helped crops grow faster and better. These fertilizers supported a growing population and helped feed more people. Finally, chemistry changed medicine. Scientists learned how to take useful chemicals from plants and make them in labs. Important medicines like aspirin, morphine, and quinine were produced in large amounts, making them more available to people around the world. This helped save lives and treat diseases more effectively.
During the 1800s, chemistry became a more organized and respected science. One of the biggest changes was that chemistry started to be taught seriously at universities. Before this time, most science was done by individuals working on their own. But now, schools in Europe and North America began to understand that experimental science, like chemistry, could help improve society and make countries stronger. Chemistry got its own professors (called university chairs) and special laboratories where students could learn both ideas and hands-on experiments. One of the most famous schools for this was the University of Giessen in Germany, where Justus von Liebig started a chemistry lab in the 1820s. His lab became a model for others around the world. Liebig believed students should learn by doing research and experiments, not just by listening to lectures. Many important chemists were trained there, and the idea of the "chemical laboratory" became common in schools. Outside of schools, scientific societies also helped chemistry grow. In 1841, the Chemical Society of London was founded. It gave chemists a place to share their work, honor great discoveries, and influence government decisions. Similar groups formed in other countries, like the Deutsche Chemische Gesellschaft in Germany. These groups helped chemists stay connected and work together. Another important part of this time was the rise of science journals. Chemists needed a way to share their discoveries with others. In 1832, Liebig started a journal called Liebigs Annalen der Chemie, where chemists could publish their findings. It was carefully reviewed by other scientists, which helped make the information trustworthy. As more journals were created, new discoveries spread faster and helped science move forward. As chemistry became more organized, it also became more of a professional career. Chemists were no longer just curious hobbyists or workers in factories, they were seen as trained professionals with special skills. Companies started building their own industrial labs and hiring chemists to help make products like medicine, fabric dyes, and metals. This helped turn chemistry into an important part of both science and industry.
20th Century Chemistry
In the 20th century, chemistry changed a lot because scientists made important discoveries about atoms and even smaller parts inside them. Before, people thought atoms were the smallest pieces of matter and could not be broken down. But in 1897, J.J. Thomson discovered the electron, a tiny negatively charged particle inside the atom. This showed that atoms were made of smaller parts. Thomson created the “plum pudding” model, imagining electrons like little raisins stuck inside a positively charged pudding. Not long after, in 1911, Ernest Rutherford did the famous gold foil experiment. He found out that the atom is not like a pudding but has a tiny, dense, positively charged center called the nucleus, with electrons moving around it mostly through empty space. In 1913, Niels Bohr improved this idea. He said electrons move in specific paths or shells around the nucleus. They can jump between these shells by gaining or losing energy. This idea helped explain why atoms give off certain colors of light, called spectral lines. However, Bohr’s model did not work well for bigger atoms, so scientists kept exploring. In the 1920s and 1930s, a new field called quantum mechanics was created. Erwin Schrödinger suggested that electrons behave like waves, and their positions can only be described by probabilities, not exact locations. Werner Heisenberg added that we cannot know both an electron’s exact position and speed at the same time. This is called the Uncertainty Principle. These ideas came together into the modern quantum mechanical model of the atom, which is the foundation of chemistry today. It helps explain not only how atoms look and behave but also why elements are arranged in the periodic table, how atoms stick together in chemical bonds, and the shapes of molecules.
In 1913, Henry Moseley used X-rays to study atoms and discovered that an element’s place in the periodic table should be based on its atomic number (the number of protons in its nucleus), not its atomic weight. This helped fix problems in the old version of the table and made it more accurate. Moseley’s work also helped scientists find missing elements by spotting gaps in the sequence of atomic numbers. At the same time, scientists were learning about radioactivity. In 1896, Henri Becquerel discovered that uranium could give off invisible rays without any outside energy. Later, Marie and Pierre Curie studied this further and discovered new radioactive elements like polonium and radium. These elements gave off energy because their atoms were unstable and could break down on their own. This showed that atoms were not unchangeable after all. These discoveries led to a new field called nuclear chemistry, which focuses on the reactions that happen in an atom’s nucleus. In the 1930s, scientists like Otto Hahn, Fritz Strassmann, Lise Meitner, and Otto Frisch discovered nuclear fission, a process where atoms like uranium split into smaller parts and release a huge amount of energy. This discovery had a huge impact. During World War II, the U.S. used nuclear fission to build the atomic bomb in a secret project called the Manhattan Project. These bombs caused massive destruction and changed the world forever. After the war, people also began using nuclear fission to make electricity in nuclear power plants. Later, scientists studied nuclear fusion, the reaction that powers the sun. Fusion could give us cleaner and safer energy, but we are still working on how to control it on Earth.
Another important breakthrough in 20th-century chemistry was the rise of physical chemistry. Physical chemistry used the principles of physics to understand matter. In the United States, an early supporter of this field was Ira Remsen, who helped improve science education by promoting hands-on experiments in chemistry classes. This helped train a new generation of scientists who were both skilled and curious. One of the most important figures in physical chemistry was Gilbert N. Lewis. He came up with the idea that atoms bond by sharing pairs of electrons. He also created the Lewis dot structure, a simple way to show how atoms are connected. His work helped people understand things like covalent bonds (where atoms share electrons), acids and bases, and chemical energy. Later, in the 1930s, Linus Pauling took these ideas even further by using quantum mechanics to explain chemical bonds. He introduced the concept of hybridization, which helped explain the shapes of molecules, like the four-cornered tetrahedral shape of methane. Pauling also created the electronegativity scale, which shows how strongly atoms attract electrons when they bond. Pauling’s impact went beyond theory. He was also a leader in using tools like X-ray crystallography and spectroscopy to figure out the exact 3D shapes of molecules. These tools became especially important in biochemistry. Pauling used them to study proteins and discovered their basic structures, such as the alpha helix and beta sheet. His work helped start the field of structural biology, which looks at how the shape of a molecule affects what it does in the body.
In the 20th century, organic chemistry, grew very quickly and made a huge impact on the world. One of the biggest changes was that chemists invented new ways to build complicated molecules with great care and precision. These new methods, like the Grignard reaction or Wittig reaction, gave scientists powerful tools to create all kinds of useful chemicals, including medicines and materials. One important part of this progress was the rise of polymer chemistry, which led to the invention of new materials called plastics. In 1935, a chemist named Wallace Carothers at DuPont created nylon, the first completely man-made fiber. This showed that large, chain-like molecules (called polymers) could be designed to have special properties, like strength or flexibility. After nylon, scientists quickly made other important materials, such as polyethylene, polystyrene, PVC (polyvinyl chloride), Teflon, and polyester. These plastics changed everyday life. They were used in packaging, clothing, cars, buildings, and much more. At the same time, pharmaceutical chemistry, the science of making medicines, grew rapidly. In the early 1900s, chemists had already made useful drugs like aspirin and barbiturates, but the discovery of penicillin in 1928 by Alexander Fleming changed medicine forever. Penicillin could fight deadly bacterial infections, and its mass production helped save countless lives, especially during World War II. After that came sulfa drugs, the first widely used antibiotics, which helped treat many infections even before penicillin was common. Later in the century, scientists made even more important medicines, including antiviral drugs for diseases like HIV/AIDS, chemotherapy drugs to treat cancer, and medications for mental health and brain disorders. New advancements in stereochemistry and chiral synthesis made medicines safer and more effective. In the final decades of the century, techniques like combinatorial chemistry, high-speed drug testing, and computer-aided drug design helped scientists discover new medicines much faster.
In the middle of the 20th century, chemistry began to focus more on understanding the molecules that make up living things. One of the most important discoveries during this time was the structure of DNA, made by James Watson and Francis Crick in 1953. They used X-ray images taken by Rosalind Franklin and base-pairing rules discovered by Erwin Chargaff to figure out that DNA is shaped like a double helix, two strands twisted around each other. These strands are held together by base pairs. Adenine pairs with thymine, and guanine pairs with cytosine. This discovery helped connect chemistry with biology and gave rise to a new field called biochemistry, which studies how chemicals work inside living things. Scientists began to study important molecules like proteins, carbohydrates, lipids, and nucleic acids in more detail. They used special tools like X-ray crystallography, NMR (nuclear magnetic resonance), and mass spectrometry to see the shapes and structures of these molecules. Researchers also started to understand how enzymes speed up chemical reactions in the body, how cells communicate, and how metabolism works to give us energy. This new knowledge helped create another field called molecular biology, which focuses on how genes work and how cells use DNA to make proteins. In the 1970s, scientists developed ways to cut and paste DNA, creating a powerful technique called recombinant DNA technology. This let them move genes from one organism to another, helping launch the field of genetic engineering. Later, in the 21st century, scientists created an even more precise gene-editing tool called CRISPR-Cas9, which allows for direct changes to DNA. These discoveries changed many areas of life. In medicine, they led to new drugs, gene therapies, and personalized treatments based on a person’s DNA. In farming, they helped create genetically modified organisms (GMOs) that grow better and resist pests. In science, they gave researchers powerful tools to explore how life works, including how we inherit traits and how species evolve.
In the 20th century, analytical chemistry changed a lot because of new and powerful tools that helped scientists study chemicals more carefully and accurately. Before this time, scientists mostly used older methods called "wet chemistry," which involved mixing chemicals, making them change color, or forming solids to find out what was in a sample. These methods worked okay but were not precise enough for the harder problems chemists faced in fields like organic chemistry, biochemistry, and materials science. One big step forward was the invention of the mass spectrometer. This tool measures the mass and charge of tiny particles called ions. Scientists like Francis Aston and Arthur Jeffrey Dempster helped improve mass spectrometry, which became super useful for finding out the weights of molecules, discovering different forms of atoms (isotopes), and identifying unknown chemicals. Mass spectrometry is so sensitive it can detect even tiny amounts of substances, down to billionths or trillionths of a gram. Another important tool was nuclear magnetic resonance (NMR) spectroscopy, first shown in the 1940s and widely used by the 1950s and 1960s. NMR lets chemists study the magnetic properties of atoms like hydrogen and carbon in molecules. This helps them understand the exact structure of molecules, how atoms bond, and how molecules move around in liquids. Later, more advanced versions of NMR allowed even deeper study of complex molecules, especially in drug research and organic chemistry. X-ray crystallography also became very important during the 20th century. This technique uses X-rays to find the three-dimensional shapes of molecules with amazing detail. At first, it was used on simple crystals, but later scientists could use it to study big molecules like vitamins, hormones, and proteins. For example, Rosalind Franklin’s X-ray images helped explain the famous double-helix structure of DNA. Over time, X-ray crystallography helped scientists learn about many complicated biological molecules, which is very important for understanding how our bodies work and for making new medicines. Other helpful tools include infrared spectroscopy, which helps identify parts of molecules by measuring vibrations, and ultraviolet-visible (UV-Vis) spectrophotometry, which helps chemists watch chemical reactions and study certain types of molecules. Together, these instruments made it possible for chemists to study chemicals in ways they never could before, speeding up discoveries and helping create new materials, medicines, and technologies.
By the late 20th century, the chemical industry got much bigger, including not only old areas like medicine and dyes but also new ones like petrochemicals (chemicals made from oil), agrochemicals (chemicals for farming), and advanced materials. One big change came from petrochemistry. Scientists learned how to turn crude oil into many useful chemicals. These chemicals were then used to make plastics, synthetic rubber, and solvents. These new materials changed everyday things like packaging, buildings, cars, and many other products. Another very important invention was the Haber process (also called the Haber-Bosch process). It was developed in the early 1900s by Fritz Haber and later made into a big industrial method by Carl Bosch. This process uses high pressure, high temperature, and a special iron catalyst to turn nitrogen gas from the air and hydrogen gas into ammonia (NH₃). Ammonia is a key ingredient in nitrogen fertilizers. The Haber process had a huge impact on farming. It allowed factories to make nitrogen fertilizers in large amounts, which helped farmers grow much more food. This helped feed the rapidly growing world population and played a big role in the Green Revolution, a time when farming became much more productive. Today, more than half of the people on Earth depend on food grown with fertilizers made using the Haber process. Without it, natural soil would not have enough nitrogen to grow enough food for everyone.
In the field of energy, chemists made big progress in creating new ways to produce cleaner and better power, so people would not have to rely so much on fossil fuels like oil and coal. One important invention was the fuel cell, which changes chemical energy directly into electricity using reactions between hydrogen and oxygen. Although the idea of fuel cells started way back in 1839 with Sir William Grove, it was not until the mid-1900s that fuel cells became practical. In the 1960s, companies like General Electric built hydrogen-oxygen fuel cells to power NASA’s spacecraft because they were reliable and clean. Later, in the 1990s and 2000s, fuel cells became important for clean energy cars and power stations. Chemists worked on making better catalysts, materials like platinum, that helped fuel cells work faster and last longer. At the same time, batteries got much better thanks to advances in chemistry and materials science. Early batteries, such as the lead-acid battery invented in 1859, were heavy and did not store much energy. Nickel-cadmium batteries, made in the early 1900s, could be recharged but had problems like toxicity and losing capacity over time. A big breakthrough happened in the 1980s when John B. Goodenough and his team created the lithium cobalt oxide cathode, which led to the lithium-ion battery. Sony started selling these batteries in 1991. Lithium-ion batteries are lightweight and hold a lot of energy, which changed portable devices like laptops and smartphones. They also helped make electric cars better, allowing them to travel longer distances and pushing more people toward cleaner transportation. Chemists also played a big role in solar energy by improving solar panels that turn sunlight directly into electricity. The first practical silicon solar cell was made in 1954 by Bell Labs scientists Daryl Chapin, Calvin Fuller, and Gerald Pearson. This showed that solar energy could work well, although it was expensive at first. Over the years, chemists and materials scientists worked on making solar cells cheaper and more efficient by improving the materials inside them.
Beyond energy, materials science helped create many important inventions in fields like electronics, space travel, and computers. One big discovery was semiconductors, like silicon and germanium. These materials made it possible to invent the transistor in 1947 at Bell Labs by scientists John Bardeen, Walter Brattain, and William Shockley. Transistors replaced bulky vacuum tubes and made electronic devices smaller, faster, and more reliable. This invention became the building block for modern computers, phones, and other technology. In the 1980s, scientists Georg Bednorz and K. Alex Müller discovered high-temperature superconductors. These materials are used in powerful magnets for MRI machines and particle accelerators and could someday help build more efficient power systems. Chemists also worked on composite materials, which are made by combining two or more substances to make something stronger or better. For example, carbon fiber reinforced plastics and advanced ceramics are light but very strong and can resist heat and corrosion. These materials are used to build airplanes that use less fuel, safer and lighter cars, and even parts for rockets and spacecraft.
Even though the 20th century brought amazing discoveries in chemistry, it also caused serious problems for people and the planet. One major wake-up call came in 1962, when scientist and writer Rachel Carson published a book called Silent Spring. In it, she warned about the dangers of using pesticides like DDT without understanding the harm they could do. These chemicals were killing birds, harming wildlife, and even making people sick. Her book helped spark the environmental movement, leading to the banning of DDT in many countries and the creation of environmental protection laws and agencies. But that was not the only concern. Chemistry was also used in ways that hurt people, especially during wars. In World War I, mustard gas was used as a weapon. In the Vietnam War, chemicals like Agent Orange were sprayed to destroy forests, but they also harmed soldiers and civilians. These tragedies led to international agreements like the Chemical Weapons Convention in 1993, which aimed to stop countries from using chemistry to make weapons. Factories also caused pollution by releasing toxic chemicals into the air, water, and soil. This included things like heavy metals, greenhouse gases, and chlorinated hydrocarbons. Problems like acid rain, holes in the ozone layer from CFCs, and huge amounts of plastic waste showed that chemical innovation could have long-term effects on the Earth. These issues taught scientists and leaders that chemistry should be used more responsibly to protect both people and the environment.
21st Century Chemistry
Chemistry in the 21st century has continued to grow and improve in exciting ways. One of the biggest changes is the use of computers to model and predict chemical reactions. This area is called computational chemistry. It lets scientists create virtual experiments and watch how atoms and molecules behave without needing to do everything in a real lab. This saves time, money, and materials. A special method called Density Functional Theory (DFT) helps chemists understand how molecules are built, how they react, and how much energy they need. In the past, these tools could only handle small, simple molecules, but now they can work with much larger and more realistic ones. This is very useful in designing new medicines, materials, and catalysts. In 2013, three scientists, Martin Karplus, Michael Levitt, and Arieh Warshel, won the Nobel Prize in Chemistry for their work in combining different types of modeling. They found a way to blend quantum mechanics with classical physics to study big, complex systems like enzymes. Another exciting development is called ultrafast laser spectroscopy. This technique uses femtosecond laser pulses (that is one quadrillionth of a second) to take snapshots of chemical reactions as they happen. It is like watching atoms and molecules moving, bonding, and changing in real time. This helps scientists better understand what is happening during reactions, including how bonds break, electrons move, and energy flows.
Scientists now use amazing tools like atomic force microscopes (AFM), scanning tunneling microscopes (STM), and X-ray photoelectron spectroscopy (XPS) to look at atoms and molecules on surfaces. These tools are very important for creating things like better catalysts, tiny sensors, and nanomaterials that help clean up pollution. Scientists can also use special tools like optical tweezers to measure the forces on just one molecule at a time. Another field is nanochemistry. Chemists work with materials that are only a few nanometers wide. These materials, like quantum dots and nanoparticles, have special properties that can be used in solar panels, tiny computer chips, and targeted drug delivery that helps treat diseases more precisely. Scientists are designing better batteries, fuel cells, and machines that split water into hydrogen and oxygen, which could help us use clean energy. In biophysical chemistry, scientists combine chemistry with biology and computer science. They study how proteins fold, how enzymes work, and how cell membranes behave. Tools like cryogenic electron microscopes (cryo-EM) and NMR machines help them see the shapes of molecules, which is very helpful in fighting diseases and creating new medicines.
In the 21st century, analytical chemistry has become much more advanced and important in many areas of science and everyday life. One big improvement has been in mass spectrometry (MS), a tool that helps scientists figure out what different chemicals are and how much of each is present. In the past, MS was mostly used for small molecules. Today, it can study large molecules, complicated mixtures, and even single cells. Modern versions, like tandem mass spectrometry (MS/MS) and high-resolution machines such as time-of-flight (TOF) and orbitrap analyzers, are incredibly sensitive. They can detect tiny amounts of a substance, as little as one part in a trillion. These tools are used in areas like medicine, drug testing, studying proteins and cells, and checking for pollution in the environment. Another big part of analytical chemistry is chromatography, which helps separate mixtures. The most common types are gas chromatography (GC), high-performance liquid chromatography (HPLC), and the newer ultra-performance liquid chromatography (UPLC). UPLC, developed in the early 2000s, works faster and gives clearer results than older methods. Often, chromatography is combined with mass spectrometry to make hyphenated techniques like LC-MS/MS or GC-MS. These powerful tools can separate and identify thousands of substances in just one experiment, which is very useful in things like medical testing, making new medicines, and checking food safety. A big trend in the 21st century is making scientific tools smaller and more portable. This is called miniaturization. One exciting result of this is the creation of lab-on-a-chip and microfluidic devices. These tiny tools can do complex chemical tests on a small chip, using only tiny drops of liquid. Because they are small and easy to carry, these devices can be used outside of a regular lab, like at a patient’s bedside, in the field, or in places with few resources. They can give fast results, which is very helpful in emergencies or remote areas. These tools are used for many things, such as checking blood sugar for people with diabetes, testing for diseases, like COVID-19 or the flu, finding toxins in water or the environment, and analyzing drugs in crime investigations.
Today, analytical chemistry works closely with data science. Modern science tools create huge amounts of data, and chemists need better computer programs to help understand it all. They use things like statistics, machine learning, and pattern recognition to find useful information in the data. This helps chemists in detecting pollution in the air, water, or soil, even at tiny amounts (less than one part per billion). It also helps them find illegal drugs or chemicals in crime scenes. It also helps in tracking new pollutants like microplastics and PFAS, which used to be hard to measure. Using special tools like ICP-MS, chemists can find heavy metals (like lead or mercury) in people or the environment In medicine, analytical chemistry helps create and test new medicines. Chemists make sure drugs are pure, safe, and work the way they should. They also check that medicines stay good over time. Groups like the FDA (Food and Drug Administration) and EMA (European Medicines Agency) use these tests to decide if a medicine can be sold.
Biochemistry in the 21st century has grown really fast. One of the biggest achievements was the Human Genome Project, finished in 2003. Scientists were able to read the entire DNA sequence of humans for the first time. This helped researchers learn more about how genes work. How they are turned on and off, and how they make proteins. Scientists have also sequenced the DNA of many other living things, like tiny bacteria, helpful plants like Arabidopsis, and fruit flies. This helped them compare genes across species and better understand how life evolved and functions. One of the most powerful tools in today’s biochemistry is called CRISPR-Cas9. Discovered in 2012 by Emmanuelle Charpentier and Jennifer Doudna, CRISPR lets scientists edit DNA quickly and accurately. It has changed the way we do genetic engineering. With CRISPR, we could fix genetic diseases, improve crops, and study what different genes do in living things Another important area is proteomics, the study of proteins. Using mass spectrometry, scientists can now identify thousands of proteins in a sample and study how they are changed or interact with each other. This helps us understand how cells work on a very detailed level. Tools like cryogenic electron microscopes (cryo-EM) allow scientists to actually see large molecules and protein machines in 3D, almost down to the atom. This technology was so important that it won the Nobel Prize in Chemistry in 2017.
One important area is called metabolomics, which is the study of tiny molecules (called metabolites) in cells and tissues. These molecules help us see what's really happening inside living things. Scientists now combine information from genomics (DNA), transcriptomics (RNA), proteomics (proteins), and metabolomics to get a complete picture of how cells work. This big-picture approach is called systems biology. It helps scientists understand complex diseases like cancer, diabetes, and Alzheimer’s by looking at how everything in a cell connects and works together. Biochemistry also helps in drug discovery and personalized medicine. Using computer modeling and new tools, scientists can design medicines that match a person’s specific needs. A field called pharmacogenomics studies how people’s genes affect the way they respond to medicine. This helps doctors choose the right drug and the right dose for each person. Another interesting area is synthetic biology. This is when scientists engineer living cells to do new jobs, like making biofuels, biodegradable plastics, or even new medicines. They do this by reprogramming cells with carefully chosen DNA instructions. In agriculture, biochemists are helping to create GMO (genetically modified organisms) and gene-edited crops that are healthier, more nutritious, and more resistant to pests, diseases, and climate change. By studying plant biochemistry, scientists are finding ways to help plants grow better and use water and nutrients more efficiently. Biochemistry is also key in solving global health problems. One example was the creation of mRNA vaccines for COVID-19. These vaccines use molecules that tell our cells to make a harmless part of the virus, helping the immune system learn how to fight it. Scientists are now working on similar vaccines for other diseases like flu, HIV, and even cancer.
In the 21st century, chemistry has also become very important in helping us create better and cleaner ways to store and use energy. One big area of progress is rechargeable batteries. Lithium-ion batteries, which first came out in the 1990s, have gotten much better over the years. Today, they are used in many things like smartphones, laptops, and electric cars. Chemists have made these batteries safer and more powerful by creating better materials for the battery parts. Some of these materials include lithium iron phosphate (LiFePO₄) and nickel manganese cobalt (NMC). Scientists are also working on new types of batteries, like lithium-sulfur, solid-state, and sodium-ion batteries. These may be cheaper, safer, and last longer, which could help even more people use clean energy. Another exciting technology is the fuel cell. Fuel cells make electricity by combining hydrogen and oxygen, and the only thing they give off is water, so they do not pollute the air. This makes them a great option for clean cars. One type, called a PEM fuel cell, is especially useful. Chemists are working on better and cheaper catalysts, which are materials that help the fuel cell work faster. One challenge with fuel cells is how to store hydrogen safely and easily. Scientists are exploring special materials, like metal–organic frameworks (MOFs) and solid–state hydrides, that can hold hydrogen in a compact and safe way.
Chemists are also leading the way in improving solar energy. The most common solar panels today are made from silicon, but scientists are working on new materials that could make solar power cheaper, lighter, and more flexible. One interesting material is called a perovskite. In 2009, perovskite solar cells could only turn about 4% of sunlight into electricity. By the early 2020s, that number had jumped to over 25%. Perovskites are cheap to make and can be used on bendable surfaces, but they have some problems. They do not last very long, and they contain lead, which can be harmful. Chemists are working to fix these issues. Other types of solar panels include dye-sensitized solar cells (DSSCs) and organic solar cells, which can be see-through or flexible. These new types of solar cells could be used in windows or on clothing. Another interesting area is called photocatalysis. This means using sunlight to make chemical reactions happen. Scientists are developing materials like titanium dioxide mixed with tiny amounts of certain metals, that can use sunlight to split water into hydrogen and oxygen or turn carbon dioxide into useful fuels like methanol or methane. This is similar to how plants do photosynthesis, and scientists call their version artificial photosynthesis. Chemists are also helping to make green hydrogen, a clean fuel, using a method called electrolysis. This process splits water using electricity, and it works even better when chemists add catalysts that help speed up the reaction. Chemists are also working on ways to capture carbon dioxide (CO₂) from the air or from factories. They are designing new materials like amine-based liquids, metal-organic frameworks (MOFs), and porous carbons that can trap CO₂. Once captured, the CO₂ can be turned into fuels, plastics, or even medicines, helping to reduce pollution and fight climate change.
Chemistry is also helping to create new materials. One example is nanomaterials. These are materials made at an incredibly small scale. Chemists can now make nanoparticles, nanotubes, and nanowires with exact shapes and sizes. This has led to discoveries like carbon nanotubes and graphene, which are super strong and great at conducting electricity and heat. These materials are now being used in batteries, tiny sensors, and advanced electronics. Another new type of material are called smart materials. These materials can change when something around them changes like temperature, light, or electric signals. For example, some materials can “remember” a shape and return to it after being bent. Others can heal themselves after getting damaged. Smart materials are used in things like robotics, medical devices, and spacecraft. In medicine, special smart gels can deliver medicine exactly when and where it is needed or help new tissue grow. Polymers, which are long chains of molecules, have also improved. Chemists can now make biodegradable polymers that break down safely or design polymers for 3D printing, medicine, and even to act like proteins or DNA. Chemists can now use machine learning and computer simulations to test and find the best materials faster than ever before. Programs like the Materials Genome Initiative help scientists go from new idea to real product more quickly. Chemists are also designing electronic and photonic materials for things like flexible phone screens, glowing displays (OLEDs), and even quantum computers. Tiny particles called quantum dots are used in colorful TVs and medical imaging. And in the race to build quantum computers, special materials are helping create more stable and powerful qubits.
In the 21st century, chemistry faces many big and complicated challenges. One of the most serious is climate change. To help stop global warming, chemists are working to create cleaner energy sources. These include better solar panels, fuel cells, and batteries that do not rely on fossil fuels. But making these technologies affordable, safe, and easy to use on a large scale is still a tough problem. Another goal is to find ways to capture carbon dioxide, a major greenhouse gas, and turn it into useful fuels or chemicals. Right now, that process uses a lot of energy and is not very efficient. Green chemistry is another important focus. Many chemical industries today use toxic substances and create a lot of waste. Chemists are now trying to design cleaner ways to make products using renewable resources, safer materials, and less energy. This shift is difficult, especially when it comes to changing how big factories operate, but it is necessary for a more sustainable future. Plastic pollution is also a major concern. Plastics are everywhere, from packaging to clothes, but they do not break down easily and often end up in oceans and soil. Chemists are working to invent biodegradable and recyclable plastics that still work well but do not harm the planet. They're also trying to find better ways to remove microplastics and other plastic waste from the environment. In the world of medicine, chemists are helping to fight antibiotic resistance and new diseases. Bacteria are becoming harder to kill. There have not been many new antibiotics in recent years. Chemists must design new drugs and ways to deliver them more effectively. There is also growing interest in personalized medicine, where treatments are made to match a person’s genes. Water shortages and polluted water are big problems in many parts of the world. Chemists are developing new ways to clean water using less energy. They are also making better sensors to detect pollutants, like pesticides and heavy metals, in the water, soil, and air. Many high-tech devices, like smartphones and electric cars, need special materials such as lithium, cobalt, and rare earth elements. But mining these materials can harm the environment, and supplies are limited. Chemists are trying to find safer ways to extract these elements, reuse them, or even replace them with better alternatives.
Types of chemistry
There are several types of chemistry. Analytical chemistry looks at which chemicals are in things. For example, looking at how much arsenic is in food. Organic chemistry looks at things that have carbon in them. For example, making acetylene. Inorganic chemistry looks at things that do not have carbon in them. One example is making an integrated circuit. Theoretical chemistry tries to explain chemical data with mathematics and computers.
A large area of chemistry is polymer chemistry. This looks at plastics. One example is making nylon. Because plastics are made of carbon, polymer chemistry is part of organic chemistry. Another area is biochemistry. This looks at the chemistry of living things. An example would be seeing how arsenic poisons people. Biochemistry is also part of organic chemistry. There are many other small branches of chemistry.
Concepts of chemistry
Matter
Matter is anything that has mass and takes up space. This means it fills up some amount of room, even if we cannot always see it. Everything around us, from tiny grains of sand to huge planets and stars, is made of matter. Even things like air or steam, which seem invisible or light, are still matter because they are made of tiny particles that have mass and take up space. We can notice matter in many ways. Some things, like a rock or a cup of water, are easy to see and touch. Other things, like the air in a room or the gas in a balloon, are harder to notice, but they are still there. You can feel them when the wind blows or when a balloon gets bigger. Matter is really important in science, especially in chemistry and physics, because it helps us understand what everything is made of and how it behaves. All matter is made up of atoms and molecules, which are tiny building blocks.
Matter can exist in different states, or forms, depending on how its tiny particles are arranged and how much energy they have. The three most common states are solid, liquid, and gas. In a solid, the particles are packed closely together in a fixed pattern. They do not move around much, which is why solids have a definite shape and volume. For example, a rock or a pencil keeps its shape unless something forces it to change. In a liquid, the particles are still close, but they are not in a set pattern. They can slide past each other, which lets liquids flow and take the shape of their container. However, liquids still keep the same volume. A cup of water stays the same amount, whether it is in a glass or a bowl. In a gas, the particles are spread far apart and move very fast. Gases do not have a fixed shape or volume. They will spread out to fill any space they are in, like air in a balloon. Gases can also be compressed or squished into a smaller space. Besides these three, there are also other, more unusual states of matter. One is plasma, which is made of super-energized particles with electric charges. Plasma is found in things like stars and lightning. Another rare state is called a Bose–Einstein condensate (BEC). It happens only at very, very cold temperatures close to absolute zero. In this state, particles move so slowly they start to act like one single particle instead of many.
Matter can be grouped into two main types based on what it's made of: pure substances and mixtures. Pure substances are made of only one kind of material and have the same properties throughout. They always have the same makeup, no matter where you find them. Pure substances can be either elements or compounds. Elements are the simplest type of pure substance. They cannot be broken down into anything simpler using normal chemical methods. Each element is made of just one kind of atom. Examples include oxygen (O₂), hydrogen (H₂), and iron (Fe). There are over 100 known elements, and they are all listed in the periodic table. Compounds are also pure substances, but they are made of two or more different elements that are chemically bonded together in a fixed ratio. This means the elements combine in a specific way to form a new substance. Some examples are water (H₂O), carbon dioxide (CO₂), and salt (NaCl). In a compound, the elements lose their individual properties and form something completely new.
Mixtures are made when two or more substances are physically combined, not chemically joined. This means each part of the mixture keeps its own properties, and you can often separate them using simple methods like filtering, boiling, or picking them apart. Mixtures come in two main types: homogeneous and heterogeneous. A homogeneous mixture (also called a solution) looks the same all the way through. The different parts are evenly mixed, and you cannot see or easily separate them. For example, when salt dissolves in water, it becomes a solution. You cannot see the salt anymore, but it is still there. Another example is air, which is a mixture of gases. A heterogeneous mixture looks different in different parts. The substances are not evenly mixed, and you can often see and separate the different parts. Examples include a salad, sand and iron filings, or oil and water. In these mixtures, the parts stay separate and can be picked out or separated by hand or simple tools.
The properties of matter help us understand how different substances act, react, and change in various situations. These properties are usually divided into two main types: physical properties and chemical properties. Physical properties are things we can see, measure, or feel without changing what the substance is made of. These include things like color, smell, taste, melting point, boiling point, density, hardness, electrical conductivity, and solubility (how well something dissolves). For example, water boils at 100°C and freezes at 0°C. One special thing about physical properties is that they do not change the substance. You can measure them many times, and the substance stays the same. For instance, if you melt ice, it turns into liquid water, but it is still H₂O. That means it’s a physical change, not a chemical one, and it can be reversed by freezing the water again. Some physical properties depend on how much of the substance you have. These are called extensive properties, like mass and volume. Others stay the same no matter how much you have. These are called intensive properties, like density and boiling point.
Chemical properties describe how a substance can change into something completely new. Unlike physical properties, which can be seen or measured without changing the substance, chemical properties can only be observed when a chemical reaction happens. These reactions change the substance's molecular or atomic structure, meaning it becomes a different substance. Some common chemical properties include flammability (how easily something burns), reactivity with acids or bases, rusting of iron, tarnishing of silver, and the ability to decompose or oxidize. For example, when wood burns, it reacts with oxygen in the air and turns into ash, carbon dioxide, water vapor, and heat. This is a chemical change, and the fact that wood can burn is a chemical property. Another example is iron rusting. When iron is exposed to air and moisture, it reacts to form rust, which is a new substance with different properties.
Atoms
The idea of atoms goes all the way back to around 400 BCE, when ancient Greek thinkers like Democritus and Leucippus came up with the idea that all matter is made of tiny, invisible particles. They called these particles "atomos," which means "uncuttable" or "indivisible." Democritus believed that atoms had different shapes and sizes and moved through empty space, combining in different ways to make everything we see. However, this idea was just a guess. It was not based on experiments or evidence. Another famous philosopher, Aristotle, had a different idea. He believed that everything was made of just four elements: earth, water, air, and fire. Because Aristotle was very popular and influential, people accepted his ideas for almost 2,000 years, and the atom theory was mostly forgotten. That changed in the early 1800s, when an English scientist named John Dalton brought the idea of atoms back. In 1803, Dalton proposed the first modern atomic theory. He said that all matter is made of atoms, and that atoms cannot be created or destroyed. He also said that all atoms of the same element are exactly the same, and that chemical reactions happen when atoms are rearranged. Dalton’s ideas were based on experiments, especially from studying how elements combine in fixed amounts. But, Dalton thought atoms were just solid spheres like a ball with no parts inside.
As scientists built better tools and did more experiments, they began to learn much more about what was inside an atom. In 1897, a scientist named J.J. Thomson discovered the electron by using a special tube called a cathode ray tube. This showed that atoms are not solid and indivisible after all. Thomson came up with the "plum pudding model," where he imagined the atom as a ball of positive charge with negative electrons scattered inside it, like raisins in a pudding. But in 1911, Ernest Rutherford did a famous experiment with gold foil that changed this idea. He found that most of the atom is empty space, and that the positive charge is packed into a tiny, dense center called the nucleus. This led to the nuclear model of the atom, where electrons orbit around a central nucleus. However, this model still did not explain why the electrons did not just crash into the nucleus. Then in 1913, Niels Bohr improved Rutherford’s model by using ideas from quantum theory. Bohr said that electrons move in fixed energy levels or shells around the nucleus. He also said that electrons can jump from one level to another by gaining or losing energy. Bohr’s model worked well for explaining the behavior of hydrogen, the simplest atom, but it did not work as well for bigger atoms. In the 1920s, scientists created an even better model using quantum mechanics. Scientists like Erwin Schrödinger, Werner Heisenberg, and Max Born showed that electrons do not move in perfect orbits. Instead, they exist in areas called electron clouds or orbitals, which are regions where electrons are likely to be found. This modern model of the atom is the most accurate one we have today and helps explain how atoms behave in chemistry and physics.
An atom is the smallest unit of matter. It is the basic building block that makes up everything around us. At the center of every atom is the nucleus, a tiny, dense part that contains two types of particles: protons and neutrons. Protons have a positive charge, while neutrons have no charge, they are neutral. The number of protons in an atom’s nucleus is called the atomic number, and it tells us what element the atom is. For example, all hydrogen atoms have one proton, and all oxygen atoms have eight protons. The mass number of an atom is the total number of protons and neutrons in the nucleus. Because protons and neutrons are both heavy (compared to electrons), almost all of the atom’s mass is in the nucleus, even though it is very small. Outside the nucleus is where the electrons are found. Electrons are much smaller and have a negative charge. In older models, scientists thought electrons moved in set paths around the nucleus, like planets orbiting the sun. But today, we know from quantum mechanics that electrons move in regions called orbitals or electron clouds. These are areas where electrons are most likely to be found, but their exact position cannot be known for sure. Electrons are also arranged in energy levels or shells around the nucleus. Each level can hold only a certain number of electrons. Atoms are electrically neutral when they have the same number of protons and electrons. But sometimes, atoms can gain or lose electrons, which changes their overall charge. When an atom loses electrons, it becomes a positively charged ion, called a cation. When an atom gains electrons, it becomes a negatively charged ion, called an anion. Also, atoms of the same element can have different numbers of neutrons. These are called isotopes. Even though isotopes have the same number of protons and act the same in chemical reactions, their different numbers of neutrons make them have slightly different masses. Some isotopes are stable, while others can break down over time, releasing energy.
The electron configuration of an atom is the way its electrons are arranged in different energy levels and areas around the nucleus. This arrangement is very important because it helps determine how the atom will react with other atoms and form chemical bonds. In today’s model of the atom, called the quantum mechanical model, electrons do not travel in neat circles around the nucleus like planets around the sun. Instead, they move around in areas called orbitals, which are regions where there is a high chance of finding an electron. These orbitals are grouped into energy levels, also called shells, which are labeled with numbers like 1, 2, 3, and so on. Each energy level has one or more subshells, which are labeled as s, p, d, and f. The first energy level (1) has only an s subshell. The second level (2) has s and p subshells. The third level (3) has s, p, and d, and so on. Each orbital can hold up to two electrons. The Aufbau principle helps scientists understand how electrons fill the space around an atom’s nucleus. According to this rule, electrons always fill the lowest energy orbitals first before moving to higher ones. The order in which electrons fill these orbitals goes like this: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, and so on. This order is based on the energy levels of the orbitals, and sometimes it can seem a bit out of order. For example, 4s fills before 3d because 4s has a lower energy level than 3d. There are also other important rules to remember when talking about electron configuration. Pauli exclusion principle says that only two electrons can fit into the same orbital, and they must spin in opposite directions. Hund’s rules says that when electrons go into orbitals that have the same energy (like three 2p orbitals), they will first go in one at a time with the same spin. Only after each orbital has one electron will they start to pair up. This helps reduce repulsion between electrons. We use a special way to write electron configurations. For example, the configuration for a carbon atom, which has 6 electrons, is: 1s² 2s² 2p². This means carbon has 2 electrons in the 1s orbital, 2 in the 2s, and 2 in the 2p. For bigger elements, we often use noble gas shorthand to save time. This means we start with the symbol of the nearest noble gas (like neon or argon) in brackets, and then continue from there. For example, sodium has 11 electrons. Instead of writing out everything, we can write: [Ne] 3s¹. Here, [Ne] stands for the first 10 electrons (1s² 2s² 2p⁶), and the 11th electron is in the 3s orbital. The valence electrons, or the electrons in the outermost shell, are very important. They decide how an atom behaves in chemical reactions, how it bonds with other atoms and what kind of compounds it can form.
The Periodic Table
A long time ago, people only knew about a few natural elements like gold, silver, copper, and iron. As science progressed, especially in the 1600s and 1700s, scientists started discovering more elements and learning about chemical reactions. In the late 1700s, a scientist named Antoine Lavoisier made one of the first lists of elements. He also suggested that elements were basic substances that could not be broken down into anything simpler. By the early 1800s, more elements had been discovered, and scientists began to see patterns in their properties. The big breakthrough came in 1869 when a Russian chemist named Dmitri Mendeleev created a version of the periodic table. He arranged the 63 known elements by increasing atomic mass and grouped elements with similar properties into columns. What was really amazing about Mendeleev’s table was that he left spaces for elements that had not been discovered yet and predicted what their properties would be. When scientists later discovered elements like gallium, scandium, and germanium, their properties matched Mendeleev’s predictions, which made his table even more accepted. Although there were some problems with his system, like elements that did not fit perfectly by mass, Mendeleev’s table helped scientists understand the relationships between different elements. In the early 1900s, Henry Moseley improved the table by arranging elements by atomic number, which solved many of the problems. He showed that elements’ properties depend on the number of protons in their nucleus. This led to the modern periodic law, which says that elements’ properties change in a regular pattern based on their atomic number. Since then, the periodic table has grown to include over 100 elements, including many that are made in labs. It has also become more complex with the addition of new groups of elements like noble gases, transition metals, and lanthanides and actinides (the f-block elements).
The periodic table is a special chart that shows all the known chemical elements in a very organized way. It is arranged based on each element’s atomic number (how many protons it has), how its electrons are set up, and how it behaves in chemical reactions. The table is built to match how atoms work, especially how electrons move around the nucleus. This setup helps scientists understand how each element will act during chemical changes. The table has rows called periods and columns called groups or families. Periods go from left to right and are numbered from 1 to 7. Each period shows how many energy levels, or electron shells, the atoms have. As you move across a period, each element gets one more proton and one more electron, and they go into the same energy level. This changes things like the size of the atom and how strongly it attracts electrons. Groups go up and down and are numbered from 1 to 18. Elements in the same group have the same number of valence electrons. These are the electrons in the outer shell of the atom. Because of this, elements in the same group act in similar ways. For example, Group 1 is called the alkali metals (like lithium and sodium). They all have one valence electron and are very reactive, especially with water. Group 17 is the halogens (like fluorine and chlorine). They have seven valence electrons and are also very reactive. Group 18 is the noble gases (like helium and neon). They have full outer shells of electrons and do not react much with other elements.
The periodic table is also split into four big sections called blocks. The s, p, d, and f blocks. These blocks are based on how electrons fill up different parts of an atom, called orbitals. The s-block includes Groups 1 and 2, plus hydrogen and helium. In these elements, the s orbitals are being filled with electrons. The p-block includes Groups 13 to 18. These elements are filling up their p orbitals. The s-block and p-blocks together make up most of the main group elements, which include both metals and nonmetals. The d-block is in the middle of the table and includes Groups 3 to 12. These are the transition metals. They are special because they can form different types of charged ions and complex compounds. The f-block is at the bottom of the table and includes the lanthanides and actinides. These elements are filling their f orbitals. Even though they are placed separately to keep the table neat, they actually belong in the 6th and 7th rows (periods). The periodic table also shows trends, or patterns, in the properties of elements. Atomic radius (the size of an atom) gets smaller across a period from left to right because the nucleus pulls electrons in tighter. But it gets larger going down a group because more electron shells are added. Electronegativity (how strongly an atom attracts electrons) usually increases across a period and decreases down a group. Ionization energy (the energy needed to remove an electron) follows a similar pattern. It increases across a period and decreases down a group.
Basic concepts
The basic unit of an element is called an atom. An atom is the smallest building block that you can cut an element into without the element breaking down (turning into a lighter element, for example through nuclear fission or radioactive decay). A chemical compound is a substance made up of two or more elements. In a compound, two or more atoms are joined to form a molecule. The tiniest speck of dust or drop of liquid, that one can see is made up of many millions or billions of these molecules. Mixtures are substances where chemicals are mixed but not reacted. An example would be mixing sand and salt. This can be undone again to produce salt and sand separately. Chemical compounds are changed by a chemical reaction. An example would be heating sodium bicarbonate, common baking soda. It will make water, carbon dioxide, and sodium carbonate. This reaction cannot be undone.
One very important concept in chemistry is that different atoms interact with one another in very specific proportions. For example, two hydrogen atoms interacting with one oxygen atom lead to the water molecule, H2O. This relationship is known as the "Law of constant proportions" and leads to the idea of "stoichiometry", a term that refers to the ratios of different atoms in chemical compounds. For example, in water, there are always exactly 2 hydrogen atoms to 1 oxygen atom. In carbon dioxide, there are exactly 2 oxygen atoms for 1 carbon atom. These relationships are described using chemical formulas such as H2O (two hydrogen atoms and one oxygen atom) and CO2 (one carbon atom and two oxygen atoms).
Mole
Because atoms of different elements react with one another in very specific proportions but atoms of different elements have different weights, chemists often describe the number of different elements and compounds in terms of the number of "moles". A "mole" of any element contains the same number of atoms: 602,214,150,000,000,000,000,000 atoms. The atomic mass of an element can be used to see how much of the element makes a mole. For example, the atomic mass of copper is about 63.55. That means about 63.55 grams of copper metal has a mole of atoms. The atomic mass of chlorine is about 35.45. That means 35.45 grams of chlorine has a mole of atoms in it.
Moles can be used to see how many molecules are in chemical compounds, too. Copper(II) chloride is an example. CuCl2 is its chemical formula. There is one copper atom (63.55) and two chlorine atoms (35.45 · 2 = 70.90). Add all the molar masses of the elements together to get the molar mass of the chemical compound (63.55 + 70.90 = 134.45). That means in 134.45 grams of copper(II) chloride, there is one mole of copper(II) chloride molecules. This concept is used to calculate how much chemicals are needed in a chemical reaction if no reactants (chemicals that are reacted) should be left. If too much reactant is used, there will be some reactants left in the chemical reaction.
Acids and bases
Acids and bases are a common type of chemical. Using the simplest definitions, acids add H3O+ hydronium ions when in water, and bases add OH- hydroxide ions when in water. Acids can react with bases: the OH- takes the extra hydrogen from H3O+ to make an extra water molecule, H2O. The other parts of the acid and base make a salt.
An example would be reacting hydrochloric acid (HCl) and sodium hydroxide (NaOH). Hydrochloric acid releases H+ and Cl- ions in water. The base releases Na+ and OH- ions. The H+ and the OH- react to make water. There is a solution of sodium chloride (NaCl) left. Sodium chloride is a salt.
This definition of acids and bases, called the Arrhenius acid-base theory, is not used by modern chemists. It is too oversimplified for what really happens in water, and cannot describe anything dissolved in another solvent like ammonia. Instead, chemists use the Brønsted–Lowry acid–base theory and Lewis acid-base theory, which are more complicated but more useful in chemistry. Instead of looking at reactions in water, these theories focus on hydrogen ions and pairs of electrons.
Usefulness
Chemistry is very useful in everyday life and makes up the foundation of many branches of science. Most objects are made by chemists (people who do chemistry). Chemists are constantly working to find new and useful substances. Chemists make new drugs and materials like paints that we use every day.
Safety
Many chemicals are harmless, but there are some chemicals that are dangerous. For example, mercury(II) chloride is very toxic. Chromates can cause cancer. Tin(II) chloride pollutes water easily. Hydrochloric acid can cause bad burns. Some chemicals like hydrogen can explode or catch fire. To stay safe, chemists experiment with chemicals in a chemical lab. They use special equipment and clothing to do reactions and keep the chemicals contained. The chemicals used in drugs and in things like bleach have been tested to make sure they are safe if used correctly.


United States: "America" redirects here. For the continent, see Americas. For other uses, see United States (disambiguation) and America (disambiguation)
May 2019
The United States of America, also known as the United States (U.S.) or simply America, is a sovereign country mostly in North America. It is divided into 50 states. 48 of these states and the District of Columbia border each other between the Pacific and Atlantic Oceans. They are bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwestern area of the continent and is separated from the other 48 states by Canada making it an exclave. Alaska is bordered by Canada to its east. The state of Hawaii is a set of islands in the Pacific located within Polynesia and is about 2,200 miles (3,500 kilometers) from the mainland. The country also possesses territories, and insular areas, in the Caribbean and Pacific. The capital city is Washington, D.C and the largest city by population is New York City with a population of 8.8 million people. With a population of 340.1 million people and an area of 3.79 million square miles (9.83 million km2), the United States is the third most populated country in the world and the fourth-largest country in the world by total area.
The land that would one day become the United States was first settled by migrating tribes from Siberia that walked across a land bridge about 20,000 years ago during the Ice Age. These people were the ancestors of the Native Americans. European colonization began in the 16th and 17th century with several European nations setting up colonies in North America. 
The thirteen colonies of Great Britain along the Atlantic coast declared independence as a nation on July 4, 1776. They issued the Declaration of Independence, which announced their independence from Great Britain and their creation of a cooperative union. The colonies defeated Great Britain in the American Revolutionary War, making it the first successful colonial war of independence in history. The Philadelphia Convention adopted the current United States Constitution on September 17, 1787; its approval the following year made the states part of a single republic with a strong central government. The Bill of Rights, making up ten constitutional amendments guaranteeing many basic civil rights and freedoms, was approved in 1791.
In the 19th century, the United States had a legal policy of manifest destiny where they believed that it was their god given right to expand across the North American continent. They conquered and took over native lands and bought territory from France, the United Kingdom, Mexico, and Russia, and took over the Republic of Texas and later the Republic of Hawaii. 
Political arguments between the farming-based South and industrial North over the growth of the institution of slavery and states' rights began the American Civil War. In 1861, the southern states separated from the union and founded their own country called the Confederate States of America after anti-slavery candidate, Abraham Lincoln won the Presidential election. The Union's victory over the Confederacy prevented a permanent split of the country and led to the end of legal slavery in the United States. By the 1870s, the national wealth was the world's largest. The Spanish–American War and World War I confirmed the country's status as a military power. In 1945, the United States came out of World War II as a superpower and was the first country with nuclear weapons. After World War II the United States along with its allies founded the United Nations. Today the United States is a permanent member of the United Nations Security Council. The United States also became engaged in an arms race called the Cold War with the Soviet Union. The United States participated in the Space Race against the Soviet Union that produced rapid advancements in rocket technology. They created the Apollo 11 rocket and it was the first to send people to the moon. It was done by NASA, an American space agency. It went up to space on July 16, 1969, carrying three astronauts: Neil Armstrong, Buzz Aldrin and Michael Collins. On July 20, 1969, Armstrong and Aldrin became the first humans to land on the moon, while Collins stayed in orbit around the Moon. In 1991, the Soviet Union broke up, ending the Cold War and leaving the United States as the only superpower. 
Today, the United States is one of the world's most ethnically mixed and multicultural nations. It is the product of large-scale immigration from many countries. The U.S. economy is the largest national economy in the world, with an estimated 2020 gross domestic product (GDP) of US$ 20.9 trillion (about a quarter of worldwide GDP).
 Geography and environment 
The United States is a federal republic of fifty states, a federal district, and several territories.
The land area of the contiguous United States is 2959064 sqmi km2 0. Alaska, separated from the contiguous United States by Canada, is the largest state at 663268 sqmi km2 0. Hawaii, occupying an archipelago in the central Pacific, southwest of North America, is 10931 sqmi km2 0 in area.
The United States is the world's fourth largest nation by total area (land and water), ranking behind Russia, Canada, and China or behind Russia, Canada, and ahead of China. The ranking varies depending on how two territories disputed by China and India are counted and how the total size of the United States is measured: calculations range from 3676486 sqmi km2 0 to 3717813 sqmi km2 0 to 3794101 sqmi km2 0. Measured by only land area, the United States is third in size behind Russia and China, just ahead of Canada.
The coastal plain of the Atlantic seaboard gives way further inland to deciduous forests and the rolling hills of the Piedmont. The Appalachian Mountains divide the eastern seaboard from the Great Lakes and the grasslands of the Midwest. The Mississippi–Missouri River, the world's fourth longest river system, runs mainly north-south through the heart of the country. The flat, fertile prairie of the Great Plains stretches to the west, interrupted by a highland region in the southeast.
The Rocky Mountains, at the western edge of the Great Plains, extend north to south across the country, reaching altitudes higher than 14,000 feet (4,300 m) in Colorado. Further west is the rocky Great Basin and deserts such as the Chihuahua and Mojave. The Sierra Nevada and Cascade mountain ranges run close to the Pacific coast, both ranges reaching altitudes higher than 14,000 feet. The Alaskan Range passes through much of Alaska and is home to Denali which stands at a height of 20,310 ft (6,190 m) above sea level and is the tallest mountain in the United States and in North America. Denali is in fact the tallest mountain in the World on land from base to summit standing at about 18,000 ft (5,490 m), which is about 4,000 ft (1,220 m) higher than Mount Everest which sits at a height of about 14,000 ft (4,270 m) from base to summit. 
The United States, with its large size and geographical variety, includes most climate types. To the east of the 100th meridian, the climate ranges from humid continental in the north to humid subtropical in the south. The southern tip of Florida is tropical, as is Hawaii. The Great Plains west of the 100th meridian are semi-dry. Much of the western mountains are alpine. The climate is dry in the Great Basin, desert in the Southwest, Mediterranean in coastal California, and oceanic in coastal Oregon and Washington and southern Alaska. Most of Alaska is subarctic or polar. Extreme weather is not unusual—the states bordering the Gulf of Mexico are prone to hurricanes, and most of the world's tornadoes happen within the country, mainly in the Midwest's Tornado Alley.
The U.S. ecology is considered "megadiverse"; about 17,000 species of vascular plants occur in the contiguous United States and Alaska, and over 1,800 species of flowering plants are found in Hawaii, few of which occur on the mainland. The United States is home to more than 400 mammal, 750 bird, and 500 reptile and amphibian species. About 91,000 insect species have been described.
The Endangered Species Act of 1973 protects threatened and endangered species and their habitats. They are watched by the United States Fish and Wildlife Service. There are 63 national parks, and hundreds of other federally managed parks, forests, and wilderness areas. The United States government owns 28.8% of the country's land area. Most of this is protected, but some is leased for oil and gas drilling, mining, logging, or cattle ranching. 2.4% is used for military purposes.
An example of animals that are native to the United States such as opossums, raccoons, pumas, and bears. Endangered animals in the United States include the jaguar, the California condor, and the Florida panther.
There are many types of small trees and shrubs in the United States. Some of these are hackberries, hawthorn, serviceberry, blackberry, wild cherry, dogwood, and snowberry. Wildflowers grow all around the United States. They even grow in deserts and places with mountains. Wildflowers include forget-me-not, fringed and closed gentians, jack-in-the-pulpit, black-eyed Susan, columbine, and common dandelion, as well as many types of aster, orchid, lady's slipper, and wild rose.
 History 
 Native Americans 
It is believed that the indigenous peoples of the continental United States, including the natives of Alaska, moved in from Asia. They began arriving more than twelve thousand years ago, if not earlier. Some, such as the pre-Columbian Mississippian culture in the southeast, developed advanced farming, grand construction, and state-level communities. The native population of America decreased after Europeans arrived, and for different reasons, mostly sicknesses such as smallpox and measles.
 European settlers 
In 1492, Italian explorer Christopher Columbus from Genoa, under contract to the Spanish crown, reached some Caribbean islands, making the first Contact with the native people. On April 2, 1513, Spanish conquistador Juan Ponce de León landed on what he called "La Florida" — the first recorded European coming on what would become the U.S. mainland. Spanish settlements in the area were followed by ones in the present-day southwestern United States that drew thousands through Mexico. French fur traders established outposts of New France around the Great Lakes; France eventually claimed much of the North American interior, down to the Gulf of Mexico. The first successful English settlements were the Colony of Virginia in Jamestown in 1607 and the Pilgrims' Plymouth Colony in 1620. The 1628 chartering of the Massachusetts Bay Colony resulted in a wave of relocation; by 1634, New England had been settled by some 10,000 Puritans. Between the late 1610s and the American Revolution, about 50,000 convicts were shipped to Britain's American colonies. Beginning in 1614, the Dutch settled along the lower Hudson River, including New Amsterdam on Manhattan Island.
 Independence and expansion 
Tensions between American colonials and the British during the rebel period of the 1760s and early 1770s led to the American Revolutionary War, fought from 1775 through 1781. On June 14, 1775, the Continental Congress, a meeting in Philadelphia, established a Continental Army led by George Washington.The Congress said that "all men are created equal" and are born with "certain natural rights," and adopted the Declaration of Independence, written mostly by Thomas Jefferson, on July 4, 1776. That date is now celebrated every year as America's Independence Day. In 1777, the Articles of Confederation established a weak federal government that operated until 1789. Morocco was the first country in the world to recognize America’s independence.
After the British defeat by American forces helped by the French, Great Britain recognized the independence of the United States and the states' sovereignty over American land west to the Mississippi River. A constitutional convention was organized in 1787 by people who wanted to establish a stronger national government, with powers of taxation. The United States Constitution was approved in 1788, and the new republic's first Senate, House of Representatives, and President (George Washington) took office in 1789. The Bill of Rights, forbidding federal restriction of personal freedoms and certifying a range of legal protections, was adopted in 1791.
Attitudes toward slavery were shifting; a clause in the Constitution protected the African slave trade only until 1808. The northern states permanently stopped slavery between 1780 and 1804, leaving the slave states of the south as defenders of the "peculiar institution." The Second Great Awakening, beginning about 1800, made evangelicalism a force behind different social reform movements, including abolitionism.
Americans' eagerness to expand westward caused a long series of Indian Wars and an Indian removal policy that removed native peoples from their land. The Louisiana Purchase of French-claimed land under President Thomas Jefferson in 1803 almost doubled the nation's size. The War of 1812, declared against Britain over different complaints and fought to a draw, strengthened U.S. nationalism. A series of U.S. military invasions into Florida led Spain to give up it and other Gulf Coast territory in 1819. The United States took over the Republic of Texas in 1845. The idea of Manifest destiny became popular during this time. The 1846 Oregon Treaty with Britain led to U.S. control of the present-day American Northwest. The U.S. victory in the Mexican–American War resulted in the 1848 cession of California and much of the present-day American Southwest. The California Gold Rush of 1848–49 further encouraged western relocation. New railways made relocation easier for settlers and increased conflicts with Native Americans. Over a half-century, up to 40 million American bison, or buffalo, were killed for skins and meat and to ease the railways' spread. The loss of the buffalo, which were valuable to the plains Indians, caused many native cultures to become gone forever.
 Civil War and industrialization 
American Civil War Reconstruction era Spanish–American War
Tensions between slave and free states mounted with arguments over the relationship between the state and federal governments, as well as violent conflicts over the spread of slavery into new states. Abraham Lincoln, a candidate of the antislavery Republican Party, was elected president in 1860. Before he took office, seven slave states declared their secession and formed the Confederate States of America. With the Confederate attack upon Fort Sumter, the American Civil War began and four more slave states joined the Confederacy. Lincoln's Emancipation Proclamation committed the Union to end slavery. Following the Union victory in 1865, three changes to the U.S. Constitution secured freedom for the nearly four million African Americans who had been slaves, made them citizens, and gave them voting rights. The war and its resolution led to a big increase in federal power.
After the war, the assassination of Abraham Lincoln was followed by the Reconstruction era, where policies were put together directed at getting back and rebuilding the Southern states while securing the rights of the newly freed slaves. The resolution of the disputed 1876 presidential election by the Compromise of 1877 ended this era, and the Jim Crow laws soon began to negatively affect many African Americans. In the North, urbanization and a never-before-seen inflow of immigrants from Southern and Eastern Europe made the country's industrialization grow rapidly. The wave of immigration, lasting until 1929, provided labor and changed American culture. High tax protections, national infrastructure building, and new banking laws also encouraged growth. The 1867 Alaska Purchase from Russia completed the country's mainland expansion. The Wounded Knee Massacre in 1890 was the last major armed conflict of the Indian Wars. In 1893, the native monarchy of the Pacific Kingdom of Hawaii was ended in a secret and successful plan led by American residents. The United States took over the archipelago in 1898. Victory in the Spanish–American War the same year proved that the United States was a world power and led to the addition of Puerto Rico, Guam, and the Philippines. The Philippines gained independence fifty years later. Puerto Rico and Guam are still U.S. territories.
 World War I, Great Depression, and World War II 
The First World War started in Europe in 1914. The United States said it was neutral and did not join the war at first. Later, the Americans helped the British and French, even though many citizens, especially those from Ireland and Germany, were against it. In 1917, the United States joined the Allies. They helped defeat the Central Powers. At the end of the war, many Americans did not want to stay involved in Europe. The Senate did not approve the Treaty of Versailles (1919). The United States stayed out of the League of Nations. The country became more isolationist. 
In 1920, the women's rights movement gained the approval of a constitutional amendment to grant women the right to vote. For most of the 1920s, the country enjoyed a period of success, decreasing the inequality in the balance of payments while profiting from industrial farms. This period, known as the Roaring Twenties, ended with the Wall Street Crash of 1929 that triggered the Great Depression. 
After his election as president in 1932, Franklin D. Roosevelt responded with the New Deal, a series of policies that increased government interference in the economy. From 1920 to 1933 a prohibition banning alcohol was in place. The Dust Bowl of the 1930s left many poor farmer communities and encouraged a new wave of emigration to the West Coast.
The United States, officially neutral during the early stages of World War II, began supplying supplies to the Allies in March 1941, through the Lend-Lease program. On December 7, 1941, the country joined the Allies' fight against the Axis Powers, after the Japanese attack on Pearl Harbor. World War II boosted the economy by providing investment capital and jobs, making many women enter the labor market. Of the significant fighters, the United States was the only nation to be enriched by war. The discussions at Bretton Woods and Yalta created a new system of an international organization that placed the country and the Soviet Union at the heart of world affairs. In 1945, when the end of the Second World War in Europe came, and an international gathering held in San Francisco drafted the Charter of the United Nations, which came into force after the war. Having developed the first nuclear weapon, the government decided to use it in the Japanese cities of Hiroshima and Nagasaki in August of that same year. Japan gave up on September 2, ending the war.
 Cold War and civil rights era 
Cold War McCarthyism Civil Rights Movement Vietnam War Watergate scandal
After World War II, the United States and the Soviet Union started the Cold War. This was because both of them thought their own type of government was the best. The United States was supported by NATO, and the Soviet Union was supported by the Warsaw Pact. They never fought each other directly, but did many proxy wars. In the Korean War, the United States sent soldiers to help South Korea. They fought Chinese soldiers that were helping communist North Korea. In the 1960s, the Cuban Missile Crisis almost led to a real war between the two countries. However, the Soviets agreed to take their missiles out of Cuba if the United States did not attack them. Because of the Cold War, many Americans were scared of communist spies taking over the United States. This started the Second Red Scare, and hundreds of people were arrested because they were communist. Later, many cases in the Supreme Court made arresting communists illegal, because it is free speech.
In 1957, the Soviet Union launched a satellite named Sputnik 1 into outer space. Later, they were the first to put people in outer space. Because of this, President John F. Kennedy wanted to send a man to the Moon. This started the Space Race, and the United States began the Apollo program, a project used for outer space. In 1969, the United States launched Apollo 11, and was the first country to send people to the Moon.
The economy of the United States grew a lot during the 1950s and 1960s, with Americans having the highest average income in the world. Because of this, many people moved to large cities and suburbs, and had more children. The country built the Interstate Highway System, which made it easier to travel and move things across the country. In 1959, Alaska and Hawaii became U.S. states.
There were many social movements in the United States during this time. The Civil Rights Movement wanted to give African Americans more rights. It was led by people such as Rosa Parks, Martin Luther King, Jr. and Malcolm X. It was very successful, and helped make many laws that protected African Americans, such as the Civil Rights Act of 1964 and 1968. John F. Kennedy was murdered in 1963, and Lyndon B. Johnson became the President. Johnson sent United States soldiers to the Vietnam War, and many people did not like this. This started the counterculture movement. Counterculture included many things, such as people who wanted black nationalism, peace, and more rights for women. In 1969, the Stonewall riots in New York marked the start of the gay rights movement.
In 1974, Richard Nixon became the first President to resign. This was because of the Watergate scandal, where people broke into the Democratic headquarters and took a lot of information to help Nixon. During the Yom Kippur War, the United States helped Israel. Because of this, countries in OPEC did not let the United States buy their oil. This started an oil crisis. In the 1970s, the country's economy had a problem with stagflation, something that happens when prices go up but production does not. When Ronald Reagan was elected in 1980, he tried to stop this with lower taxes and less government control over the economy. These changes were called Reaganomics. The Cold War ended in 1991. This was because the Soviet Union dissolved. With no Soviet Union, the United States became the largest superpower in the world.
 Modern history 
September 11 attacks War in Afghanistan (2001–present) Iraq War Great Recession
Under President George H. W. Bush, the country took on a global dominant role worldwide, as in the Gulf War (1991). The longest economic expansion in modern American history, from March 1991 to March 2001, spanned the presidency of Bill Clinton and the dot-com bubble. A civil lawsuit and a sex scandal led to his impeachment in 1998, although he managed to finish his period. The 2000 presidential election was one of the most competitive in American history, it was settled by the Supreme Court: George W. Bush, son of George H. W. Bush, became president, even though he gained fewer votes than his opponent Al Gore.
On September 11, 2001, the terrorists of the Al-Qaeda group attacked the twin towers of the World Trade Center in New York City (which were destroyed) and the Pentagon near Washington, D.C., in a series of attacks that killed nearly three thousand people. In response, the Bush administration launched the "War on Terror." At the end of 2001, U.S. forces invaded Afghanistan, removed the Taliban government and destroyed Al-Qaeda's training camps. Taliban insurgents continued to fight a guerrilla war. In 2002, Bush began to discuss a regime change in Iraq. With a lack of support from NATO and without a clear UN order for military intervention, Bush organized a coalition of governments to begin an invasion. The coalition forces quickly invaded Iraq in 2003 and ended the government of Saddam Hussein. The following year, Bush was re-elected as the most voted president in an election.
In 2005, Hurricane Katrina, which would end up being the deadliest natural disaster in national history, caused severe destruction along the Gulf Coast: the city of New Orleans was mostly destroyed, with 1833 dead.
On November 4, 2008, during a global economic downturn, Barack Obama was elected president, having been the first African American to take office. In May 2011, American Special forces managed to kill Osama bin Laden, hiding in Pakistan. The following year, Barack Obama was re-elected. Under his second term, he led the war against the Islamic State and restored diplomatic relations with Cuba.
On November 8, 2016, the Republican Party leader Donald Trump defeated former First Lady Hillary Clinton for presidency.
The massacres in Orlando of June 12, 2016 at the gay disco Pulse (51 dead) and in Las Vegas on October 1, 2017 (60) are listed as the largest massacres in the country since 9/11. The murder of George Floyd in late May 2020 sparked protests all over the world that demanded racial justice. On January 6, 2021, the United States Capital in Washington, D.C. was stormed during a riot and violent attack against the U.S. Congress.
 Government 
The United States is the world's oldest surviving federation. It is a constitutional republic and representative democracy, "in which majority rule is tempered by minority rights protected by law." The government is controlled by a system of checks and balances from the United States Constitution. The constitution is the country's main legal document. There are three branches. They are the executive branch, the legislative branch, and the judicial branch. State governments and the federal government work in very similar ways. Each state has its own executive, legislative, and judicial branches. The executive branch of a state government is led by a governor, instead of a president.
 Executive branch 
The executive branch is the part of the government that enforces the law. Members of the U.S. Electoral College elect a president who is the leader of the executive branch, as well as the leader of the armed forces. The president may veto a bill that Congress has passed, so it does not become a law. The President may also make "executive orders" to ensure that people follow the law.
The president is in charge of many departments that control much of the day-to-day actions of the government. For example, the Department of Commerce makes rules about trade. The president chooses the heads of these departments and also nominates federal judges. However, the Senate, part of the legislative branch, must agree with all of the people the president chooses. The president may serve two 4-year terms. 
 Legislative branch 
The legislative branch makes laws. The legislative branch is called the United States Congress. Congress is divided into two "houses".
One house is the House of Representatives. The Representatives are each elected by voters from set areas within the states. The number of Representatives a state has is based on how many people live there. Representatives serve two-year terms. The total number of representatives today is 435. The leader of the House of Representatives is the Speaker of the House.
The other house is the Senate. In the Senate, each state is represented equally, by two senators. Because there are 50 states, there are 100 senators. The President's treaties or appointments of officials need the Senate's approval. Senators serve six-year terms. The Vice President of the United States serves as president of the Senate. In practice, the vice president is usually absent from the Senate, and a senator serves as president pro tempore, or temporary president, of the Senate.
Representatives and senators propose laws, called "bills", in their respective houses. A bill may be voted upon by the entire house right away or may first go to a small group, known as a committee, which may recommend a bill for a vote by the whole house. If one house votes to pass a bill, the bill then gets sent to the other house; if both houses vote for it, it is then sent to the president, who may sign the bill into law or veto it. If the president vetoes the bill, it is sent back to Congress. If Congress votes again and passes the bill with at least a two-thirds majority, the bill becomes law and cannot be vetoed by the president.
Under the American system of federalism, Congress may not make laws that directly control the states; instead, Congress may use the promise of federal funds, or special circumstances such as national emergencies, to encourage the states to follow federal law. This system is both complex and unique.
 Judicial branch 
The judicial branch is the part of government that interprets what the law means. The Judicial Branch is made up of the Supreme Court and many lower courts. If the Supreme Court decides that a law is not allowed by the Constitution, the law is said to be "struck down" and is no longer a valid law.
The Supreme Court is made up of nine judges, called justices, who are nominated by the President and confirmed by the Senate. One of these justices, called the chief justice, heads the court. A Supreme Court justice serves until he or she dies or resigns. When that happens, the president nominates someone new to replace the justice who left. If the Senate agrees with that choice, the person becomes a justice. If the Senate does not agree with the president's choice, then the president must nominate someone else.
Famous court cases such as Marbury v Madison (which was decided in 1803) have firmly established that the Supreme Court is the ultimate interpreter of the United States Constitution and has the power to strike down any law that conflicts with it.
 Politics 
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  Donald Trump, President of the United States since 2025
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  JD Vance, Vice President of the United States since 2025
The United States of America consists of 50 states, 5 territories, and 1 district (Washington D.C.). States can make laws about things inside the state, but only federal laws can apply to more than one state or dealing with other countries. In some areas, if the federal government makes laws that say different things from the state laws, people must follow the federal law. Each state has a constitution of its own, different from the federal (national) constitution. Each of these is like the federal constitution because they say how each state's government is set up, but some also talk about specific laws.
The federal and most state governments are dominated by two political parties: the Republicans and the Democrats. There are many smaller parties; the largest of these are the Libertarian Party and the Green Party. People help in political campaigns that they like. They try to persuade politicians to help them; this is called lobbying. All Americans are allowed to do these things, but some have and spend more money than others, or in other ways do more in politics. Some people think this is a problem, and lobby for rules to be made to change it.
The USA's large cultural, economic, and military influence has made the foreign policy of the United States, or relations with other countries, a topic in American politics, and the politics of many other countries.
 Political divisions 
 States 
The United States conquered and bought new lands over time, and grew from the original 13 colonies in the east to the current 50 states, of which 48 of them are joined together to make up the contiguous United States. These states, called the "lower 48", can all be reached by road without crossing a border into another country. They go from the Atlantic to the east to the Pacific in the west. There are two other states which are not joined to the lower 48 states. Alaska can be reached by passing through British Columbia and the Yukon, both of which are part of Canada. Hawaii is in the middle of the Pacific Ocean.
Washington, D.C., the national capital, is a federal district that was split from the states of Maryland and Virginia in 1791. Not part of any US state, it used to be in the shape of a square, with the land west of the Potomac River coming from Virginia and the land east of the river coming from Maryland. In 1846, Virginia took back its part of the land. Some people living in DC want it to become a state, or for Maryland to take back its land, so that they can have the right to vote in Congress.
 Territories and possessions 
The United States territories and possessions consist of sixteen lands that do not state, many of which are colonial territories. None of them have any land borders with the rest of the US. People live in five of these places, which are de facto American:
Puerto Rico
American Samoa
Guam
U.S. Virgin Islands
Northern Mariana Islands
The Philippines was a possession of the United States. Palau, the Federated States of Micronesia, and other Pacific island nations were governed by the United States as a United Nations "Trust Territory". All of these places have become independent: the Philippines in 1946, Palau in 1947, and Micronesia in 1986.
The U.S. armed forces has bases in many countries, and the U.S. Navy's base at Guantanamo Bay was rented from Cuba after that country had a Communist revolution.
 Counties and cities 
All the states are divided into administrative subdivisions. Most of them are called counties, but Louisiana uses the word "parish," and Alaska uses the word "borough."
There are many cities in the United States. One city in each state is the state capital, where the government of the state meets and the governor works. This city is not always the largest in its state. For example, the city with the most people living in is New York City in New York State, but the state capital is Albany, New York. Some other big cities are Los Angeles, California; Chicago, Illinois; Seattle, Washington; Miami, Florida; Indianapolis, Indiana; Las Vegas, Nevada; Houston and Dallas, Texas; Philadelphia and Pittsburgh, Pennsylvania; Boston, Massachusetts; Denver, Colorado; St. Louis, Missouri, Memphis, Tennessee, Atlanta, Georgia, San Francisco, California, San Diego and Detroit, Michigan.
 Foreign relations and military 
The United States is very influential in global economics, politics, and the military. It is a permanent member of the United Nations Security Council and the headquarters of the United Nations is in New York City. It is a member of the G7, G20, and Organization for Economic Co-operation and Development. Almost all countries have embassies in Washington, D.C., and many have consulates around the country. Likewise, nearly all nations host American diplomatic missions. However, Iran, North Korea, Bhutan, and Taiwan do not have formal diplomatic relations with the United States. The United States has a "special relationship" with the United Kingdom and strong ties with Canada, Australia, New Zealand, Japan, South Korea, and Israel.
The president is the commander-in-chief of the country's armed forces and appoints its leaders, the secretary of defense and the Joint Chiefs of Staff. The United States Department of Defense administers the armed forces, including the Army, Marine Corps, Navy, and Air Force. The Coast Guard is run by the Department of Homeland Security in peacetime and by the Department of the Navy during times of war. In 2008, the armed forces had 1.4 million personnel on active duty, along with several hundred thousand each in the Reserves and National Guard for a total of 2.3 million troops. The Department of Defense also employed about 700,000 civilians, not including contractors.
The military budget of the United States in 2011 was more than $700 billion, 41% of global military spending and equal to the next 14 largest national military expenditures combined. At 4.7% of GDP, the rate was the second-highest among the top 15 military spenders, after Saudi Arabia. U.S. defense spending as a percentage of GDP ranked 23rd globally in 2012 according to the CIA. The proposed base Department of Defense budget for 2012, $553 billion, was a 4.2% increase over 2011; an additional $118 billion was proposed for the military campaigns in Iraq and Afghanistan. The last American troops serving in Iraq departed in December 2011; 4,484 service members were killed during the Iraq War. Approximately 90,000 U.S. troops were serving in Afghanistan in April 2012; by November 8, 2013 2,285 had been killed during the War in Afghanistan.
 Economy 
The United States has a capitalist economy. The country has rich mineral resources, with many gold, coal, and uranium deposits. Farming makes the country among the top producers of, among others, corn (maize), wheat, sugar, and tobacco. Housing contributes about 15% to the gross domestic product (GDP) of the United States. America produces cars, airplanes, and electronics. About 3/4 of Americans work in the service industry.
 Science and technology 
The United States is the world's foremost scientific power. It has the most Nobel Prize winners of any country. The U.S. spends more on research and development than any other country. It is the leading country in artificial intelligence development.
Notable American inventions are: the telephone, the electric telegraph, the electric light, the cinema, the gramophone, the airplane, the internet, and the video game console. Although the U.S. did not invent the automobile, the world's first mass-produced car was American.
 Demographics 
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The United States of America has people of many different race and ethnic backgrounds. 80% of the people in the United States descend from European immigrants. Many people are descended from Germany, England, Scotland, Ireland, Africa, and Italy. 13% of the people in the United States are African-American. Most of them descend from the African slaves that were brought to America. African Americans are concentrated in the Southern United States. Asian-Americans make up only 5% of the population in America but make up a bigger portion in the west coast. For example, in California, Asian-Americans make up 13% of the population of that state. Hispanic-Americans or people of Latin origins make up 15% of the nation. Mexicans are the largest Hispanic national group, followed by Puerto Ricans, Cubans, Salvadorans and Dominicans. The original peoples, called Native American, American Indians, or Amerindians and Inuit (Eskimos) are a very small group. There are 574 federally recognized Native American tribes in the United States.
11% of the people in the United States are foreign-born. 18% speak a language other than English at home. For people 25 and older, 80% are high school graduates while 25% have a bachelor's degree or higher.
The 2000 Census counted self-reported ancestry. It identified 43 million German-Americans, 30.5 million Irish-Americans, 24.9 million African-Americans, 24.5 million English-Americans, and 18.4 million Mexican Americans.
The United States has the largest number of immigrants of any country in the world. The United States attracts immigrants from other countries due to the American Dream. Most immigrants in the United States come from Mexico, China, India, the Philippines and El Salvador. 
 Money 
The social structure of the United States has a big range. This means that some Americans are much, much richer than others. The average (median) income for an American was $37,000 a year in 2002. However, the richest 1% of Americans have as much money as the poorest 90%. 51% of all households have access to a computer and 41% had access to the Internet in 2000, a figure which had grown to 75% in 2004. Also, 67.9% of American families owned their homes in 2002. There are 200 million cars in the United States, two for every three Americans. The debt has grown to over $21,000,000,000,000.
 Religion 
There are many different religions in the U.S. Statistically, the largest religion is Christianity, including groups such as Catholicism and Protestantism. Other religions include Hinduism, Islam, Judaism, Unitarian Universalism, Wicca, Druidry, Baha'i, Raelism, Zoroastrianism, Taoism, and Jainism. Religions which were founded within the United States include Eckankar, Satanism, and Scientology. Native American religions have various animistic beliefs.
The United States is one of the most religious countries in the Western World, and most Americans believe in God. The number of Christians in the U.S. has gone down. 86.2% called themselves Christian in 1990 and 78.4% said this in 2007. The others include Judaism (2.3%), Islam (0.8%), Buddhism (0.7%), Hinduism (0.4%), and Unitarian Universalism (0.3%). Those who have no religion are at 16.1%. There is a large difference between those who say that they belong to a religion and those who are members of a religious body of that religion.
Doubts about the existence of a God, gods or goddesses are higher among young people. Among the non-religious population of the U.S., there are deists, humanists, ignostics, atheists, and agnostics.
 Language 
English (American English) is the de facto national language. Although there is no official language at the federal level, some laws (such as U.S. naturalization requirements) standardize English. In 2010, about 230 million, or 80% of the population aged five years and older, spoke only English at home. Spanish, spoken by 12% of the population at home, is the second most common language and the most widely taught second language. Some Americans advocate making English the country's official language, as it is in at least twenty-eight states. Both Hawaiian and English are official languages in Hawaii by state law.
While neither has an official language, New Mexico has laws providing for the use of both English and Spanish, as Louisiana does for English and French. Other states, such as California, order the publication of Spanish versions of certain government documents including court forms. Many jurisdictions with large numbers of non-English speakers produce government materials, especially voting information, in the most commonly spoken languages in those jurisdictions.
Several insular territories grant official recognition to their native languages, along with English: Samoan and Chamorro are recognized by American Samoa and Guam, respectively; Carolinian and Chamorro are recognized by the Northern Mariana Islands; Spanish is an official language of Puerto Rico and is more widely spoken than English there.
Many Native American languages in the United States are endangered.
 Education 
In most states, children are required to attend school from the age of six or seven (generally, kindergarten or first grade) until they turn eighteen (generally bringing them through twelfth grade, the end of high school); some states allow students to leave school at sixteen or seventeen. About 12% of children are enrolled in parochial or nonsectarian private schools. Just over 2% of children are homeschooled.
 Culture 
American popular culture goes out to many places in the world. It has a large influence on most places, especially the Western world. American music is everywhere, and American movies and television shows can be seen in most countries.
 Federal holidays 
Flag
The American flag is made up of 50 stars on a blue background and has 13 stripes, seven red and six white. It is one of many symbols of the United States like the Bald Eagle. The 50 stars represent the 50 states. The red stands for courage, the blue stands for justice, and the white represents peace and cleanliness. The 13 stripes represent the 13 original colonies.
Cuisine
A hamburger is one of the popular foods of the United States. Fast food in the United States is home to many regional cuisines such as the Cuisine of the Southern United States, also known as Southern food. There are Americanized versions of Chinese, Greek, Japanese, Italian and Mexican cuisine. Native American cuisine is the cuisine of the indigenous Native Americans. A lot of American dishes are influenced by many countries around the world. American cuisine has Native American, British, French, German, and Spanish influences. Soul food is traditional southern African American food.
Music
The most popular genres in the United States are rock and roll, pop, country, R&B, and hip hop. Native American music is the indigenous music of the United States. American singers that became global superstars include Whitney Houston, Michael Jackson, and Madonna. 
Sports
Native Americans played lacrosse before Europeans arrived. Baseball is the country sport for the United States, and American football is the most popular sport. Basketball is also very popular in the USA, which the USA has its own league called the NBA.
Video games
The video game industry of the United States is one of the largest of any country. It is the second largest market for video games after China. Many of the world's largest video game developers are based in the USA, like Take-Two Interactive, Electronic Arts, Activision Blizzard, and Xbox Game Studios.


Georg Forster: Johann George Adam Forster, also known as Georg Forsternb Forster was baptised "Johann George Adam Forster", with the English spelling "George", widely used in the Danzig area at the time, possibly chosen commemorating the family's ancestors from Yorkshire. The German form of his name is also common in English (for example, Thomas P. Saine's English-language biography is titled "Georg Forster"), which helps to distinguish him from George Forster, a contemporaneous English traveller. (ˈɡeːɔʁk ˈfɔʁstɐ, 27 November 1754 – 10 January 1794), was a German naturalist, ethnologist, travel writer, journalist and revolutionary. When he was young, he went with his father. Johann Reinhold Forster on many scientific trips. One of these was James Cook's second trip to the Pacific. Forster wrote about this trip in the book A Voyage Round the World. The book helped contribute to the ethnology to people in Polynesia. It still is a respected work. Because of this book, Forster was let into the Royal Society when he was 22. He was thought to be one of the founders of modern scientific travel literature.
Forster went back to Continental Europe after his trips. Forster decided then to have many jobs in education and learning. He taught natural history at the Collegium Carolinum in the Ottoneum, Kassel (1778–84). He then worked at the Academy of Vilna (1784–87). In 1788, he was the head librarian at the University of Mainz. Here, he did lot of scientific work on essays on botany and ethnology . He also translated and wrote a lot of books about travel and exploration. For example, he wrote a German translation of Cook's diaries.
Forster was a large figure in the Enlightenment in Germany. He talked closely with many of his close friends. His ideas, writings and personality influenced Alexander von Humboldt. Humboldt was a famous scientist in the 19th century.Daum 2019b 19–21, 43 When France took control of Mainz in 1792, Forster played a big role in the Mainz Republic (the earliest republican state in Germany). During July 1793 and while he was in Paris as a delegate of the young Mainz Republic, Prussian and Austrian coalition forces regained control of the city and Forster was declared an outlaw. Forster was not able to go back to Germany. He was separated from his friends and family. In early 1794, he died in Paris of illness.
 Early life 
Georg Forster was born in Nassenhuben on 27 November 1754.Thomas Berghof 2000 xixnb Some sources say that the birth took place in the rectory of Hochzeit. Hochzeit is a village very close to Nassenhuben on the other side of the Motława river. Nassenhuben is a village near Danzig which is now Mokry Dwór, Poland.Enzensberger 1996 10Uhlig 2004 18nb People don't know exactly when he was born as there are many different stories as to when he was exactly born. Older writings usually say that he was born on 26 November common in earlier literature. The baptism registries of Nassenhuben and of list 27 November as date of birth and 5 December as date of baptism. Both him and his father say that he was born on 27 November, however by both his father and mother and father. Reinhold's diary entry for 27 November 1772, however, says "This day was George's birthday & we were all very happy." Georg was the oldest of seven surviving children of Johann Reinhold Forster, a Reformed Protestant pastor and scholar, and his wife Justina Elisabeth, Nicolai.Thomas Berghof 2000 xixHoare 1976 15-16 When George was young, Georg liked the study of nature. When his father learned natural history from the books of Carl Linnaeus, he taught his son biology. He also taught George Latin, French and religion.Hoare 1976 21-22Uhlig 2004 19-20 In 1765, Reinhold got a commission(a written instruction) by the Russian government to inspect colonies that were near Saratov on the Volga River. They were mostly settled by German colonists.Hoare 1976 25-26 Ten-year old Georg went his father on this journey. The journey was 4000 km mi -2 on long. It led to the Kalmyk Steppe and Lake Elton where they got collected hundreds of samples plants. George helped his father with naming and identification.Hoare 1976 31
On October 1765, George Forster went to Saint Peter's School in St Petersburg.Uhlig 2004 26 While Forster was in school, his father made reports about the colony.Hoare 1976 32-33 His report was very critical of the voivode(the military leader) of Saratov. He also thought the conditions of the colony were bad. Because of this, the Forsters left Russia without payment because they were angry at Grigory Orlov.Uhlig 2004 26Hoare 1976 33-36 The Forsters went on a journey from Kronstadt to London. On the journey, Georg learned English and practiced Russian. They got to London on 4 October 1766.Uhlig 2004 27Hoare 1976 36 Georg was 12 when they got to London. Georg translated Lomonosov's history of Russia into English. He also added on to the book to include recent events. The book was printed and was presented to the Society of Antiquaries on 21 May 1767.Gordon 1975 30-31Uhlig 2004 28 In June 1767, father moved to Warrington to became a teacher at Warrington Academy. He succeeded Joseph Priestley. This left Georg behind in London. He became an apprentice there with a merchant. He was an apprentice until the rest of the family got to England in September 1767.Uhlig 2004 29Hoare 1976 50-51 He moved to Warrington. In Warrington, Georg learned classics and religion from John Aikin. He learned mathematics from John Holt. He learned French and natural history from his father.Hoare 1976 52Steiner 1977 12
 Around the world with Captain Cook 
The Forsters moved back to London in 1770.Hoare 1976 67 Reinhold Forster got many scientific contacts and became a member of the Royal Society in 1772.Hoare 1976 68–69 When Joseph Banks left Cook's expedition, Reinhold was invited by the British Admiralty to join James Cook's second expedition to the Pacific Ocean(1772–75). Georg Forster went with his father in the expedition. He became the draughtsman to his father. Reinhold had to work on scientific reports of any discoveries that they made. It was published when they got back from the expedition.Aulie 1999a
They got onto the HMS Resolution for Cook's second expedition on 13 July 1772, in Plymouth. The ship got them first to the South Atlantic. Then it went through the Indian Ocean and the Southern Ocean. While they were around the Southern Ocean, they went to the islands of Polynesia. They finally went around Cape Horn back to England on 30 July 1775. On their journey, they went to New Zealand, the Tonga islands, New Caledonia, Tahiti, the Marquesas Islands and Easter Island. They went the most south anyone has ever been. They almost discovered Antarctica. The journey disproved the Terra Australis Incognita theory. The Terra Australis theory claimed there was a big continent in the South that people were able to live in.Thomas Berghof 2000 xxii
Georg Forster first studied zoology and botanics of the southern seas with his father. He did this mostly by drawing animals and plants. Georg, however, also went with his own interests. It led to independent missions in geography and ethnology.Daum 2019a He quickly learned the languages of the Polynesian islands. He wrote many reports on the people of Polynesia. They are very popular today. In his reports, he talks about the people of the southern islands with empathy, sympathy and without Western or Christian bias.Ackerknecht 1955 85–86
Louis Antoine de Bougainville went to Tahiti a few years before Forster's trip. His reports said that the people there were a type of noble savage romanticism. Forster, however, thought that the South Pacific Islands were very intelligent.Ackerknecht 1955 86–87 He wrote about many different social structures and religions that he saw on the Society Islands, Easter Island, Tonga and New Zealand. He wrote about the differences with the different people. He also noticed that the languages of the islands were all scattered but were usually alike. He wrote that the Nomuka islands had languages, vehicles, weapons, furniture, clothes, tattoos, beards were almost exactly the same with tribes on Tongatapu.The journey had many scientific results that were very helpful. However, the Forsters and Cook and his officers were very unkind to each other. This was because Reinfield Forster had a large temper.Thomas Berghof 2000 xxii-xxvi Cook also didn't allow for the Forsters to spend more on botany and the Forster's science. Cook didn't allow scientists on his third journey because of the Forsters.Saine 1972 22
 Founder of modern travel literature 
People was annoyed with the Forsters after his trip as well. Lord Sandwich was annoyed with Johann Reinhold Forster's first chapter in his book. He tried to change. Forster, however, said that him being corrected However, Forster did not want to have his writing corrected "like a theme of a School-boy". He wouldn't allow any compromise.Aulie 1999a Because of this, the book was written by Cook. The Forsters were not allowed to compile the book. They did not get payment for the work, either. While Lord Sandwich and Reinhold Forster were arguing, Georg put out an unofficial book on their travel. In 1777, the book A Voyage Round the World in His Britannic Majesty's Sloop Resolution, Commanded by Capt. James Cook, during the Years, 1772, 3, 4, and 5 was published. It was published six weeks before the official version came out. The unofficial version was very popular. Georg got lots of fame from this. In 1778–80, Georg, published it in German. The poet Christoph Martin Wieland like the book. He said it was the most important one of his time. Even today, it was one of the most important journey descriptions written. The book changed German literature, culture and science. It inspired many scientists such as Alexander von Humboldt.Smith 1990 218 It also inspired many modern ethnologists.
Forster's German translation was seen as very looked-through. It was scientifically correct. It was also seen as exciting and easy to read. Most travel literature of this time was a basic writing of data. Georg's book was, however seen as, colourful and reliable ethnographical. They were very detailed and sympathetic. He also wrote about philosophy in books in his observations.Thomas Berghof 2000 xiii-xiv He focused on the behaviour of people, their customs, habits, religions and social organization. In A Voyage Round the World he wrote about the songs from Polynesian people. He included lyrics and notation. The book is one of the most important writings that is about the Southern Pacific from before European influence had become more significant.
 Forster at universities 
A Voyage Round the World made Georg Forster have scientific recognition in Europe. The Royal Society made him a member on 9 January 1777. He was not even 23 years old at the time. He also got other titles from academies from Berlin to Madrid.Uhlig 2004 75 Georg, however didn't get any money from getting these titles.
He went to Paris to look for the American revolutionary Benjamin Franklin in 1777. He wanted to talk with him. In 1778, he went to Germany become a natural history professor at the Collegium Carolinum in Kassel. Georg met Therese Heyne there. She was the daughter of the classicist Christian Gottlob Heyne. Heyne later became one of the first independent female writers in Germany. Georg later married Heyne in 1785(at that time, Georg had already left Kassel). Their marriage was seen as not very happy. They had had two surviving children, Therese Forster and Clara Forster. While Forster was still in Kassel, Forster like to talk with many people who were important in the Enlightenment. Some people he talked to was Lessing, Johann Gottfried Herder, Christoph Martin Wieland and Goethe. He also got cooperation with the Collegium Carolinum in Kassel and the University of Göttingen where his friend Georg Christoph Lichtenberg worked. Together, they founded and published the scientific journal Göttingisches Magazin der Wissenschaften und Litteratur.Saine 1972 27
By 1783, Forster saw that talking with all of with these people led him away from science. It was also pushing him into deeper debt.Saine 1972 33 He was known to not be very good with money.Thomas Berghof 2000 xx Because of this, Forster was happy to get a job from the Polish–Lithuanian Commonwealth Commission of National Education. He became the Chair of Natural History at Vilnius University in 1784.Reintjes 1953 50 At first, he did well in Vilnius. After some time, however, he began to feel isolated. Most of the people that he knew were still scientists from Germany that he met before.Saine 1972 43–48 In 1785, Forster went to Halle where put in a thesis on the plants of the South Pacific for a doctorate in medicine. Forster's plans to build a natural history scientific centre could not get enough financial support from authorities in Polish–Lithuanian Commonwealth. His famous speech about natural history in 1785 went wouldn't be noticed or even printed until 1843. Eventually, he broke the contract six years before it was over. This is because Catherine II of Russia had asked Forster to go around the world with him on his journey(the Mulovsky expedition). If he came with him, he would be paid as a professor in Saint Petersburg. This made a conflict between Forster and the Polish scientist Jędrzej Śniadecki. Catherine II of Russia, however, decided to not let him go on his journey. After that, Forster left Vilnius. He then went in Mainz. Here he became the head librarian at the University of Mainz. He succeeded Johannes von Müller who was a friend of Forster. He made sure that Forster would succeed him when Müller moved to become the administration of Elector Friedrich Karl Josef von Erthal.Saine 1972 59
While Forster was a librarian, he published essays very often on explorations. He continued to be a very good translator. For example, he wrote about Cook's third journey to the South Pacific. He also wrote and about the Bounty expedition. He translated Cook's and Bligh's diaries from those journeys into German.
Forster was also interested in indology. When he was going to go on his failed expedition that was funded by Catherine II, one of his main goals was to go to India. He translated the Sanskrit play Shakuntala with a Latin version that was written by Sir William Jones. This helped influence Johann Gottfried Herder. It improved German interest in indology.Ackerknecht 1955 85
 Views from the Lower Rhine 
In mid 1790, Forster and Alexander von Humboldt went on a long journey through the Southern Netherlands, the United Provinces, and England. The finished in Paris. Forster wrote about this journey in a three volume book series called Ansichten vom Niederrhein, von Brabant, Flandern, Holland, England und Frankreich im April, Mai und Juni 1790 (Views of the Lower Rhine, from Brabant, Flanders, Holland, England, and France in April, May and June 1790). It was published in 1791–94. Goethe said about that this book makes someone to read if again and travel the journey themself. The book talks about the history of art that were influential for art as A Voyage Round the world was for ethnology.Saine 1972 103
Forster's biggest interest, however, was with the behaviour of people. The uprisings in Flanders and Brabant and the revolution in France made him very interested in that. His journey through the Netherlands and England where people were developed made him make a political opinion. Because of this, he became a confident opponent of the ancien régime. Like many other German scholars, he welcomed the revolution as a result of the Enlightenment. A little bit after he heard about the Storming of the Bastille in 30 July 1789, he wrote to his father-in-law. In his note he wrote about how beautiful to see the philosophy that happened. 
 Life as a revolutionary 
 Foundation of the Mainz Republic 
The French revolutionary army that was under General Custine got control of Mainz on 21 October 1792. Two days after this, Forster joined in creating a Jacobin Club. It was called "Freunde der Freiheit und Gleichheit" ("Friends of Freedom and Equality"). He helped in organizing the Mainz Republic in 1793. The first one made in Germany was a democracy. Forster became the vice-president the their administration. He was a candidate in the election for the local parliament, the de Rheinisch-Deutscher Nationalkonvent (Rhenish-German National Convention). He was an editor of de Die neue Mainzer Zeitung oder Der Volksfreund (The new Mainz newspaper or The People's Friend) from January to March 1793. In his first article that he made, he wrote:
This freedom did not last very long. In July 1973, French troops ended the Mainz Republic.
Forster was not in Mainz when France took over. Since he was part of the Mainz National Convention, he and Adam Lux went to Paris to apply for Mainz to become a part of the French Republic. The application was accepted, but didn't have any effect since Mainz was took over by France. Forster lost his library and his things. He decided to stay in Paris.
 Death in revolutionary Paris 
Emperor Francis II made a decree(or law) that would give punishments on German people who helped the French French Revolutionary government. Forster became an outlaw because of this. He was placed under the Imperial ban. 100 ducats were put on his head. Because of this, he could not go back to Germany. He did not have his wife because she stayed in Mainz with her children and future husband Ludwig Ferdinand Huber. He also did not have any way to make money. He stayed in Paris. Paris had just started the Reign of Terror under the rule of Maximilien Robespierre. Forster was able to see the difference between the promises of the revolution of happiness and its cruel practices. Many German supporters of the revolution like Friedrich Schiller turned back from their opinions from the terror. Forster, however did not turn back from his revolutionary ideals from the Reign of Terror. He saw what happened in France as a force that could not be slowed. Forster thought that had to become calmer and if they didn't, France could destroy even more.Saine 1972 152
In January 1794 when he was 39, Forster died from rheumatic illness before the Reign of Terror was its peak.Reintjes 1953 136 He was planning to go to India at the time.
 Views on nations and their culture 
Forster had some Scottish family. He was born in born in Polish Royal Prussia. This made him a Polish subject by birth. He worked in Russia, England, Poland and in German countries of his time. Finally, he died in France. He worked in different places. He travelled a lot from when he was a youth. His thoughts made very big scientific discoveries from the Enlightenment. It also people different views on ethnic and national communities.
In his opinion, all human beings had some feelings and imagination. They are used in different ways, however. These different ways makes different cultures and civilizations. Forster said cultures like Tierra del Fuego is at a lower level of development than European culture. He also said that living on places like that is harder and there is less chance to have higher culture. This opinions were one of the biggest examples of 18th-century German cosmopolitanism.
He used insulting words against Poles with prejudice in his letters when he was in Vilnius and in a diary from when he when through Poland. He, however, but he never showed it in his publications. It was only known after he had died when these conversations and diaries were shown to the public. Forster's writings were seen as scientifically based. Forster's prejudice against Poland usually taken as factual in Imperial Germany and Nazi Germany. The "Polnische Wirtschaft" (Polish economy) stereotype was probably because of his letters.
Forster's thoughts and attitude got him into trouble with other countries. It made not welcome by anyone. He wanted a revolution too much in Germany. He was too proud in England. He didn't like Polish science in Poland. He wasn't popular enough and was ignored in France.
 Legacy 
After Forster's died, most of his books were forgotten. The only place they were remembered were in some circles. This was mostly because he was a part of the French Revolution. People like him differently throughout history. Their opinion on usually changed with their political beliefs. After the Napoleonic era, he Germans thought that he was a traitor. People thought this even though people like Karl Wilhelm Friedrich Schlegel wrote good things about him.
His life was revived a little bit in the buildup to the 1848 revolution.Saine 1972 14-15 He was, however, forgotten in Wilhelm II and Nazi Germany. Here, the only interest in Forster was from his thoughts of Poland. In the1960s in East Germany, however, people began to remember him more. This is because people thought that he showed class struggle. The GDR research station in Antarctica that was opened on 25 October 1987 was named after him. The Alexander von Humboldt foundation named a scholarship program after him. The scholarship was for foreign people from developing countries. He was a very good German ethnologist. His works are seen as very helpful in Germany's ethnology.
The ethnographical items collected by Georg and Johann Reinhold Forster are now presented as the Cook-Forster-Sammlung (Cook–Forster Collection) in the Sammlung für Völkerkunde anthropological collection in Göttingen. Another collection of items collected by the Forsters is on display at the Pitt Rivers Museum in Oxford.


Multiculturalism in the United Kingdom: Multiculturalism is the presence of several distinct cultural or ethnic groups within any given population of people. There are many reasons for multiculturalism to occur within any society, often through trade, migration, or politics. In history when many cultures come in contact with each other, multiculturalism is brief as society developes a new culture with the integration of people, science, technology and environmental changes. Multiculturalism is therefore a transitional state, that will form a single identifiable cultural in time. Multiculturalism is a modern concept of society, used by international politics and organisations, such as the United Nations, socialism, and some world religions as an ideal to bring peace and order to the world. 
Multiculturalism in the UK has its roots in the early seventeenth century. The UK had the biggest Empire in the history of the world - the British Empire. In the nineteenth century, it covered roughly 25% of the world's land surface and ruled around one-fifth of the entire population of the world. In the age of colonialism, the culture of all the colonies, like India, Australia, New Zealand, Egypt, and many other countries collided together. From 1801-81, the United Kingdom saw many immigrants arrive on British shores due to a booming economy domestically. In this period, over 2,000,000 people from Ireland moved to Great Britain, and over 1,500,000 from Germany and other parts of Europe arrived as well.
Since the time of the British Empire, many people have moved to the UK. After World War II, the UK needed more people to fill labour shortages, so it motivated Commonwealth citizens to come to Britain; viewed by many as the "mother country". During the Great War, one quarter of a million Belgians came to Britain to escape the wrath of the war. During the 1930s before World War II, Jews started to migrate to the UK with the rise of Hitler and fascism across the continent. During the 1940s to 1960s, Polish people were invited to come and stay in the United Kingdom with the promise of jobs and a house. Due to the massive migration of Polish people since, the Polish community is deeply anchored in present society. From the 1950s to 1960s immigrants from Pakistan and India settled in the UK. The year 1972 saw a further increase in Asian arrivals in the United Kingdom, those who had been expelled by dictator Idi Amin of Uganda. Though the immigrants helped the UK by contribution to the workforce, racism was a big problem in British society.
Since 2016, immigration from outside Europe has increased considerably in the UK, as it has in most European countries. 
Most immigrants come and live in cities, where there are other people from their community. In the past they mostly settled in seaports. Immigrant communities in London, Liverpool and Glasgow are very old, and were started by sailors. Chinese people moved out of the cities and started laundries and restaurants, often in small country towns where they were the only immigrants. George Formby made several songs about "Mr. Wu", a Chinese laundry man in the 1930s.
In the 1960s, the UK made a change to immigration policy. The immigration policy of Britain became more about tolerating immigrants, but not actively caring about integration. In 1962, the Commonwealth Immigrants bill was passed to restrict immigration. There was quite a lot of discrimination against immigrants. The punk singer John Lydon, who was born in London in 1956, called his autobiography No Irish, No Blacks, No Dogs. His parents were poor Irish immigrants who settled in North London. People say these words were used by landlords then. That may not be true, but there were certainly signs saying “no West Indians”. As Lydon says, Irish people blend in better than the Jamaicans.
Enoch Powell, when he was Minister for Health, recruited nurses for the NHS from the Caribbean. Later, in 1968 he made a speech and said that if the United Kingdom let too many immigrants in, there would be bloodshed in the streets.
The Race Relations Act 1965 was the first law in the UK to say that discrimination on the "grounds of colour, race, or ethnic or national origins" in public places in Great Britain was prohibited. It was followed by more, stronger, laws. 
Today, there is still a strong connection with many of the old colonies and most of them are still part of the Commonwealth of Nations. Due to this history, immigrants from all over the world come to the UK and bring with them their food, religion, and music; this forms the multicultural society of the UK. 
About 14.4% of the people in the United Kingdom in 2021 were born overseas. About 3,346,000 of them lived in London. 18% of people counted in the 2021 Census said they belonged to a Black, Asian, mixed or other ethnic group. In the Community Life Survey 2019/20 84% of these people said they felt strongly that they belonged to Britain. 
Although 'multiculturalism' initially seemed like a good idea on paper, it has proven difficult in practice given some new groups' desire for greater recognition and rights in recent years. The UK has increased its multicultural representation in recent years as well but is still struggling with issues related to 'multiculturalism'. Overall, it's important to understand and respect each cultural group without giving them preferential treatment- doing so can help create a more unified nation that is far richer from a cultural perspective.
 The multicultural face of the UK 
The following table shows that the UK is home to numerous ethnic minorities. Most immigrants come from India, Poland, Pakistan, and Ireland. Around 90% of immigrants who entered the UK went to England. They settled in English cities, giving England the largest number of cultural districts. 
Language plays an important part in the multicultural aspect of Britain. English is the main language for 92% of the UK (48.9M people). Less than 5% of the population aged 3 to 15 had a main language other than English in 2011. Foreign languages are concentrated in London, where 21% of people don't speak English, or at least not well. These are the top 5 languages spoken at home other than English: Polish, Indian dialect, Arabic, French, and all other Chinese. However, in the UK, 1.6% of the British population doesn't speak English at all.
There are numerous cultural districts in which immigrants of a nation have settled and brought their culture with them to their new homeland. In Brick Lane, in London's East End, mainly people from Bangladesh have settled. There, for example, there are also street names that have been translated into Bengali under the English sign. The street is best known these days for its South Asian restaurants and street markets. Since the 19th century, the Richmond district has been shaped primarily by German immigrants. After a German school was founded there, the district became even more attractive as an emigration destination for Germans.
Multiculturalism can also be seen in food. 
From 2018 to 2019, there was a total of 103,379 hate crimes recorded by the police in England and Wales, and 8% of hate crimes were related to religion.
This multiculturalism is also caused by the increasing birth rate of other ethnic groups in England: in 2016, 90,500 births from other ethnic groups and in 2020, 158,000. 
 London 
In London, the capital of the UK, we find over 200 languages spoken and nearly one-third of the population was born abroad. It is considered the most multicultural city in Europe for some. As seen in the table above, only 43.4% are white British. This is because most of them are moving to the countryside instead of the city, which is a rural migration. It is a city filled with culturally diverse areas, especially Chinatown with its Chinese bakeries, restaurants, and supermarkets/stores, Camden Town and Brixton that was declared as the unofficial capital of British, African, and Caribbean descent. It is also home to many religions.


Nelson Mandela: Mandela
Nelson Rolihlahla Mandela (18 July 1918 – 5 December 2013) was a South African politician and activist. On 27 April 1994, he was made the first President of South Africa elected in a fully represented democratic election. He was also the first black President of his country, South Africa.
Mandela was born in Mvezo, South Africa to a Thembu royal family.
His government focused on throwing out the legacy of apartheid by ending racism, poverty, inequality, and on improving racial understanding in South Africa. Politically a believer in socialism, he served as the President of the African National Congress (ANC) from 1991 to 1997 and adopted new Constitution of South African in 1996 that prohibits all discrimination, based on language, religion, handicap and sexual orientation, not only on racism. Internationally, Mandela was the Secretary General of the Non-Aligned Movement from 1998 to 1999.
Mandela received more than 250 honors, including the 1993 Nobel Peace Prize, the US Presidential Medal of Freedom, and the Soviet Order of Lenin. He is often referred to by his Xhosa clan name, Madiba, or as Tata ("Father"). Mandela was described as a hero, and his actions gave thousands of people hope.
Mandela was sick for several years during his retirement. He was hospitalized in late summer of 2013 from a continuous lung infection. Mandela died on 5 December 2013 in Houghton Estate, Johannesburg from a respiratory tract infection. He was 95 years old.
 Early life 
Nelson Rolihlahla Mandela was born on 18 July 1918 in Mvezo, Umtata (now Mthatha), Transkei, South Africa. He had thirteen siblings by the same father, and two mothers. His parents were Gadla Henry Mphakanyiswa and Nosekeni Nonqaphi . His given name was Rolihlahla, a Xhosa name meaning pulling the branch of a tree or informally, troublemaker. He was a member of the Thembu royal family. On his first day of school, he was given the name Nelson by his teacher Miss Mdingane. Giving children in Africa English names was a custom among Africans during that period.
Mandela's father died when he was twelve. Mandela then lived with the local regent who sent him to school. He was the first member of his family to go to a school. He was expelled from Fort Hare University in 1941, because he led a group of students on political strike. After he was expelled, Nelson found a good job as a night watchman.
 Anti-apartheid activity 
In 1944, Mandela helped start the African National Congress Youth League. He was soon a high-ranked leader of the group.
He wanted to free South Africa without violence, but the government started killing and hurting protesters. He then started Umkhonto we Sizwe with Walter Sisulu and other people in the African National Congress that he admired, such as Mahatma Gandhi.
A trial was later held and became known as the Rivonia Trial. Mandela was on trial because of his involvement in sabotage and violence in 1962. He was sentenced to life in prison, and was sent to Robben Island, but was transferred to Victor Verster Prison in 1988. In 1990, he was let out of Victor Verster Prison after 26.5 years. He left prison after de Klerk removed a ban on the African National Congress. He ordered Mandela's release. He then received the Nobel Peace Prize in 1993, with former State President of South Africa, Frederik Willem de Klerk.
 Presidency 
Mandela won the general election in April 1994. His inauguration was in Pretoria on 10 May 1994. Many people around the world saw his inauguration on television. The event had 4000 guests, including world leaders from different backgrounds. Mandela was the first South African President elected in a completely democratic election.
As South Africa's first black President, Mandela became head of the Government of National Unity which was under controlled by the African National Congress (or ANC). The ANC had no knowledge in politics, but had representatives from the National Party and Inkatha. In keeping with earlier promises, de Klerk became first Deputy President, while Thabo Mbeki was chosen second.
Although Mbeki had not been his first choice for president, Mandela soon trusted Mbeki throughout his presidency. This allowed Mbeki to organize policy details. Mandela moved into the presidential office at Tuynhuys in Cape Town. He would settle into the nearby Westbrooke Manor. Westbrooke was renamed Genadendal. Preserving his Houghton home, he also had a house built in his home village of Qunu. He visited Qunu regularly, walking around the area, meeting with local people who lived there, and judging tribal problems.
He faced many illness at age 76. Although having energy, he felt left out and lonely. He often entertained celebrities, such as Michael Jackson, Whoopi Goldberg, and the Spice Girls. He became friends with a number of rich business people, like Harry Oppenheimer and British monarch Elizabeth II on her March 1995 state visit to South Africa. This resulted in strong judgment from ANC anti-capitalists. Despite his surroundings, Mandela lived simply, donating a third of his $552,000 wealth to the Nelson Mandela Children's Fund, which he had founded in 1995. In that same year, Mandela published his autobiography, Long Walk to Freedom.
Although in favor of freedom of the press, Mandela was important of much of the country's media because it was owned and run by many middle-class whites. Mandela became known for his use of Batik shirts, known as Madiba shirts, even on normal events. Mandela had never planned on serving a second term in office. Mandela gave his farewell speech on 29 March 1999, after which he retired. Mandela's term ended on 14 June 1999. Thabo Mbeki succeeded Mandela as President of South Africa.
 Nobel Prize 
He won the Nobel Peace Prize for his leadership for his anti-apartheid activism in 1993. After receiving the prize he said:
<blockquote>"We stand here today as nothing more than a representative of the millions of our people who dared to rise up against a social operation whose very essence is war, violence, racism, oppression, repression and the impoverishment of an entire people."</p>
</blockquote>
 Personal life 
Mandela was married three times and has six children. He had seventeen grandchildren, and a growing number of great-grandchildren. Though physically non-emotional with his children, he could be stern and demanding.
Mandela married Evelyn Ntoko Mase in October 1944. They had two children. Mandela remained married to Evelyn until they divorced in 1957. Evelyn died in 2004. He then married Winnie Madikizela in 1958. They had two daughters. The couple filed for separation in 1992. They divorced in 1996. Mandela married again to Graça Machel, on his 80th birthday in 1998. She was the widow of Samora Machel. Machel was the former Mozambican president and ANC ally who was killed in an air crash 12 years earlier.
Though publicly criticizing him on several events, Mandela liked United States President Bill Clinton. Mandela personally supported him during his impeachment trial in 1998.
 Public retirement 
In June 2004, Mandela announced that he was retiring from public life. Mandela said "Don't call me, I will call you". Although continuing to meet with close friends and family, the Nelson Mandela Foundation denied invitations for him to appear at public events and most interview requests.
 Health 
On 27 March 2013, Mandela was hospitalized in Pretoria from a lung infection. It was reported on 28 March that he was responding well to treatment. Mandela was again hospitalized on 7 June from another lung infection, On 23 June, his condition was announced to be critical. On 26 June, it was announced that Mandela was put on life-support. On 4 July, Mandela's family announced that Mandela was under life-support and he was in a permanent persistent vegetative state. The next day, the South African government denied the fact that Mandela was in a vegetative state. Mandela was discharged from the hospital on 1 September 2013.
 2013 death rumor 
Many South Africans thought that Mandela died overnight on 26 June after he was removed from his life support. The South African government said that Mandela is still alive despite the rumor that he died. It was later reported that the rumor was just a death hoax. CNN also reported that Mandela died, but later fixed the report soon afterwards. Photos were taken with Mandela and First Lady Michelle Obama as proof that Mandela was still alive.
Death
Mandela died on 5 December 2013 at his home at Houghton Estate, Johannesburg from complications of a respiratory tract infection, aged 95. He was surrounded by his family when he died. His death was announced by President Jacob Zuma.
On 6 December, Zuma announced a national mourning for ten days. An event for an official memorial service was held at the FNB Stadium in Johannesburg on Tuesday 10 December. He declared Sunday 8 December a national day of prayer: "We call upon all our people to gather in halls, churches, mosques, temples, synagogues and in their homes to pray and hold prayer services and meditation reflecting on the life of Madiba and his contribution to our country and the world."
Funeral
Mandela's body lay in state from 11 to 13 December at the Union Buildings in Pretoria. A state funeral was held on Sunday 15 December in Qunu. David Cameron, Barack Obama, Raul Castro, Bill Gates, and Oprah Winfrey were there.
Burial
On 28 June Mandela's family were arguing about where to bury Mandela. On 29 June the South African government announced that a memorial service for Mandela will be held 10 to 14 days after his death at Soccer City. On 1 July it was announced that if Mandela were to die he might become the first non-British person to be honored at Westminster Abbey. Queen Elizabeth II honored Mandela with a thanksgiving service at Westminster Abbey in early 2014. This made Mandela the first non-British person to be honored at Westminster Abbey. Mandela was buried in the village of Qunu in the Eastern Cape of South Africa. Qunu is where he grew up.
 Honors 
In South Africa, Mandela is sometimes called by his Xhosa clan name of Madiba.
Nelson Mandela was honored with the following:
 In 1990, Mandela received the Bharat Ratna Award in India. 
 In 1992 received Pakistan's Nishan-e-Pakistan.
 In 1992, he was awarded the Atatürk Peace Award by Turkey. He refused the award, because of human rights violations committed by Turkey at the time. He later accepted the award in 1999.
 In 1993, Mandela won the Nobel Peace Prize with F. W. de Klerk for their work during the civil rights revolution in South Africa.
 In 1993, Mandela received the key of the city of Chicago, Illinois from Mayor Richard M. Daley.
 In 2007, Mandela was honored with a statue in Westminster Abbey, London, England.
 In 2009, the United Nations made 18 July Mandela Day.
 In 2012, the Praia International Airport in Cape Verde was renamed as the Nelson Mandela International Airport.
 In 2013, a statue of Mandela was unveiled in the South African embassy outside of Washington, D.C..
 The city of Johannesburg awarded him Freedom of the City.
 Sandton Square in Johannesburg was renamed Nelson Mandela Square in March 2004.
 The Nelson Mandela Bay Stadium was named in his honor.
 The Nelson Mandela Bridge, in Johannesburg was also named in his honor.
 Mandela was awarded the US Presidential Medal of Freedom by then-President of the United States George W. Bush. 
 Mandela was awarded the Order of Canada.
 Mandela was the first living person made an honorary Canadian citizen.
 Mandela was the last recipient of the Soviet Union's Lenin Peace Prize from the Soviet Union. 
 Mandela first recipient of the Al-Gaddafi International Prize for Human Rights
 Mandela was honored with the Order of the Aztec Eagle by the Mexican government.
 A park in Leicester, England was named Nelson Mandela Park was named after Mandela. 
 Elizabeth II awarded him the Bailiff Grand Cross of the Order of St John.
 Mandela was also awarded the Order of Merit by Elizabeth II.
Movies
Mandela has been portrayed in movies and television. In the 1997 movie, Mandela and de Klerk, Sidney Poitier plays Mandela. Dennis Haysbert plays Mandela in Goodbye Bafana (2007). In the 2009 BBC television movie, Mrs Mandela, Nelson Mandela is played by David Harewood. In 2009, Morgan Freeman plays Mandela in Invictus (2009). Terrence Howard also plays Mandela in the 2011 movie Winnie Mandela. Mandela appeared as himself in the 1992 American movie Malcolm X. In Mandela: Long Walk to Freedom he was played by Idris Elba.
Legacy
By the time of his death, Mandela had come to be widely considered "the father of the nation" within South Africa. He is also seen as "the national liberator, the savior, its Washington and Lincoln rolled into one". Throughout his life, Mandela had also faced criticism. Margaret Thatcher attracted international attention for describing the ANC as "a typical terrorist organization" in 1987. She later made favors to release Mandela from prison. Mandela has also been criticized for his friendship with political leaders such as Fidel Castro, Muammar Gaddafi, Akbar Hashemi Rafsanjani, and Suharto.


Psychology: Psychology is the study of the mind and brain. It studies thoughts, feelings, and behaviors in humans and animals. Psychology aims to explain how the mind works. It also looks at how our actions relate to how we think.
A lot of the research in psychology is done on humans. However, animals are also used in research. Examples of this are classical conditioning and operant conditioning. 
Psychology is a vast subject area. It covers many topics. It is divided into branches. Psychology has a lot in common with other fields of research. Ideas in psychology overlap with ideas in the sciences of anatomy, biology, neuroscience and physiology. 
A person who works in the field of psychology is called a psychologist. A psychologist tries to understand how the mind works so that they can help people and animals. They must go through higher education for many years in order to become a professional. These practitioners attempt to explain how the mind functions by itself (individual) and with others (social). They also see how the mind affects the body. They work with social, behavioral, and cognitive sciences.
 Branches 
Psychology has been split up into smaller parts called branches. These are subjects in psychology that try to answer a particular group of questions about how people think. The branches of psychology that are often studied are:
 Abnormal psychology, the study of the minds of people who have mental illnesses.
 Clinical psychology, which looks into prevention and treatment of mental illness.
 Cognitive psychology, the study of how people think, use language, remember and forget, and solve problems.
 Cross-cultural psychology, the study of how culture influences human behavior.
 Developmental psychology, the study of how people develop and change from childhood to adulthood. This includes what used to be called "child psychology".
 Educational psychology, the study of how people learn.
 Evolutionary psychology, the study of how evolution has shaped how people think and behave.
 Neuropsychology, the study of how human behavior relates to the brain and nervous system.
 Perceptual psychology, the study of how the mind perceives the world.
 Personality psychology, the study of personality (which is how a person thinks, feels, and behaves).
 Political psychology, the study of how politicians behave and why.
 Social psychology, the study of how groups of people work together in society.
 Rehabilitation psychology, which studies the behaviour of people with chronic physical, psychological and neurological illnesses and rehabilitates them.November 2024
 Methods 
 Scientific approaches 
Psychology is a type of science, so research psychologists use many of the same types of methods that researchers from other natural and social sciences use. 
Psychologists make theories to try to explain a behavior or pattern they see. Based on their theory, they make predictions. Then, they carry out experiments or collect data to see if their prediction is right or wrong. 
Some types of experiments cannot be done on people because it would take too long, cost too much money, risk people's health, or would be unethical. There are also other ways psychologists study the mind and behavior scientifically, and test their theories. Psychologists might wait for some events to happen on their own; they might look at patterns among existing groups of people in natural environments; or they might do experiments on animals (which can be simpler and more ethical to study).
Just like in other fields of science, a good psychological theory can be proven wrong as new information about a subject is learned. Just like in any natural science, psychologists can never be completely sure that their theory is correct. If a theory can be proved wrong, but experiments do not prove it wrong, it is more likely that the theory is accurate. This is called falsifiability.
Psychologists use many tools as part of their daily work. Psychologists use surveys to ask people how they feel and what they think. They may use special devices to look at the brain and to see what it is doing. Psychologists use computers to collect data as they measure how people behave in response to pictures, words, symbols, or other stimuli. Psychologists also use statistics to help them analyze the data that they get from their experiments.
 Symbolic and subjective approaches 
Not all psychology is scientific psychology. Psychodynamic psychology and depth psychology try to interpret dreams to understand the unconscious mind. They are older approaches to psychology begun by Carl Jung. He was interested in finding methods to measure personality traits.
Humanistic psychology and existential psychology believe that it is more important to understand personal meaning than to find causes and effects of mental processes and behaviors.
 Psychologists 
Psychologists are people who work in the field of psychology. A psychologist may work in either basic research or applied research. Basic research is the study of people or animals to learn more about them. Applied research uses what is learned from basic research to solve real-world problems. A qualified clinical psychologist can become a therapist or counsellor. 
To become a psychologist, a person must first get a basic degree at a university and go to graduate school. A Master's degree, either MSc (Master of Science) or MA (Master of Arts), allows for work such as a school psychologist. A doctorate degree takes a longer time to earn because it includes doing research and writing a detailed report. A doctoral graduate uses the initials PhD or DPhil (Doctor of Philosophy). Some clinical psychologists earn a Doctor of Psychology degree and use the initials PsyD after their name. The American Psychological Association say that people need a PhD (or PsyD) and a current state license in the U.S. to call themselves a psychologist.
The words psychologist and psychiatrist may be confused with each other. A psychiatrist has graduated from medical school and uses the initials MD or its equivalent (MB ChB in London University, for example). A psychiatrist or doctor may work with a psychologist by prescribing and checking the effects of medications.