the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
Teotihuacan was a very large city, one of the largest at that time.
After Teotihuacan declined the Toltecs became powerful.
Things made by the Toltecs have been found from the southern parts of the U.S. all the way to Costa Rica.
A famous Toltec god is Quetzalcoatl.
The Toltec culture declined too, and it was succeeded by the Aztecs.
The Aztecs called their own empire Mexico.
A famous Aztec king was Moctezuma II.
In 1519 the Spanish explorer Hernán Cortés came to Mexico.
The Aztecs thought he was the returned Quetzalcoatl, so they did not want to fight against him.
Cortes allied himself with the enemies of the Aztecs.
In 1521 they conquered the Aztec capital Tenochtitlan.
The Aztec Empire became part of Spain.
It was called New Spain.
In 1810 the Mexican priest Miguel Hidalgo started the Mexican war of independence.
In 1821 the Spanish finally retreated and Mexico became independent.
The first leader of independent Mexico was Agustin de Iturbide.
He set up the First Mexican Empire and became emperor.
But the Mexicans were not happy with him, and in 1823 the country became a republic.
A man who was very important in Mexico in the early 19th century was Antonio López de Santa Anna.
He was the president of Mexico 11 times.
When he became a dictator, Texas declared independence (1836).
The Battle of the Alamo was part of this Texas Revolution.
Between 1846 and 1848 there was war between Mexico and the United States.
In this war Mexico lost its large northern areas, which became the southwestern United States.
After this war Santa Anna was sent away to Venezuela.
Between 1858 and 1861 there was war again, between liberals and conservatives.
The liberal Benito Juárez won the war and became president afterwards.
Juarez stayed president until France invaded Mexico and made Maximilian of Habsburg emperor of the Second Mexican Empire.
But Maximilian was very unpopular.
After more war he was executed in 1867, and Juarez became president again.
Conservatives thought Juarez had too much power.
In 1876 they ousted him, and made Porfirio Díaz, a general who had won a battle against the French, president.
Porfirio Díaz made the country wealthier, but the poor people became poorer.
Franciso I. Madero started the Mexican Revolution in 1910.
The next 10 years the country was in chaos.
There were many presidents who ruled for a short time and all kinds of people fought against each other.
Famous people from this period are Emiliano Zapata, Pancho Villa and Francisco I. Madero.
When Álvaro Obregón became president in 1920 the fighting calmed down.
In 1929 President Plutarco Elías Calles founded the National Mexican Party, PNM.
The party was later renamed Institutional Revolutionary Party, PRI.
The party would rule for a very long time.
Most PRI presidents were not popular, it was said that they were only president to become richer themselves.
An exception was president Lázaro Cárdenas.
He was president between 1934 and 1940.
After several decades more and more people became unhappy with the PRI.
In 1968 security forces shot at protesters, this caused several hundred deaths and became known as the Tlatelolco massacre.
Another uprising was in 1994 when Zapatistas rebelled in the province Chiapas.
Mainly through ballot box fraud the PRI managed to stay into power until 2000, when Vicente Fox of the National Action Party, PAN, was elected president.
In total the PRI had governed Mexico for 71 years.
Mexico is a constitutional federal democracy ruled by a president.
The president is elected every 6 years.
The current president is Andrés Manuel López Obrador.
Parliament has a Senate and House of Deputies.
Mexico is in the southern part of North America.
It is roughly shaped like a triangle.
Mexico is more than 3000 km (1,850 miles) long from northwest to southeast.
Mexico is between two large seas: the Pacific Ocean in the West and the Gulf of Mexico and the Caribbean Sea in the East.
Mexico has two large peninsulas.
Baja California in the northwest, and Yucatán in the southeast.
In central and western Mexico are the Sierra Madre mountains.
In the Sierra Madre is the Pico de Orizaba, the highest mountain of Mexico.
In central Mexico there are also a few volcanoes like the Popocatépetl and the Iztaccíhuatl.
The Pico de Orizaba is also a volcano.
In the north of Mexico are deserts.
In the south are tropical rainforests.
Some rivers in Mexico are the Río Bravo (known in the US as the Rio Grande), the Río Balsas, the Río Pánuco, and the Río Yaqui.
Mexico is the most populous Spanish-speaking country in the world.
It is also the second most populous country in Latin America (after Brazil).
60% of Mexicans have Native American and European forefathers; these are called mestizos.
Almost 30% of Mexicans are pure Native American and 10% are European.
Most Mexicans (90%) speak Spanish.
10% of the Mexicans speak a Native American language, like Nahuatl, the language of the Aztecs, Maya or Zapotec.
Non-indigenous ethnic groups in Mexico speak another foreign language such as Arabic or Japanese.
Most people in Mexico are Catholic (89%) and 6% are Protestant.
Related page
1821 establishments in North America
The Atlantic Ocean is the world's second largest ocean.
It covers a total area of about .
It covers about 20 percent of the Earth's surface.
It is named after the god Atlas from Greek mythology.
Geologic history
The Atlantic formed when the Americas moved west from Eurasia and Africa.
This began sometime in the Cretaceous period, roughly 135 million years ago.
It was part of the break-up of the supercontinent Pangaea.
The east coast of South America is shaped somewhat like the west coast of Africa, and this gave a clue that continents moved over long periods of time (continental drift).
The Atlantic Ocean is still growing now, because of sea-floor spreading from the mid-Atlantic Ridge, while the Pacific Ocean is said to be shrinking because the sea floor is folding under itself or subducting into the mantle.
The Atlantic Ocean is bounded on the west by North and South America.
It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea and Barents Sea.
It connects with the Mediterranean Sea through the Strait of Gibraltar.
In the southeast, the Atlantic merges into the Indian Ocean.
The 20° East meridian defines its border.
In the southwest, the Drake Passage connects it to the Pacific Ocean.
The Panama Canal links the Atlantic and Pacific.
The Atlantic Ocean is second in size to the Pacific.
It occupies an area of about .
The volume of the Atlantic, along with its adjacent seas (the seas next to it), is 354,700,000 cubic kilometres.
The average depth of the Atlantic, along with its adjacent seas, is .
The greatest depth is Milwaukee Deep near Puerto Rico, where the Ocean is  deep.
The Atlantic Ocean has important ocean currents.
One of these, called the Gulf Stream, flows across the North Atlantic.
Water gets heated by the sun in the Caribbean Sea and then moves northwest toward the North Pole.
This makes France, the British Isles, Iceland, and Norway in Europe much warmer in winter than Newfoundland and Nova Scotia in Canada.
Without the Gulf Stream, the climates of northeast Canada and northwest Europe might be the same, because these places are about the same distance from the North Pole.
The main feature of the Atlantic Ocean's seabed is a large underwater mountain chain called the Mid-Atlantic Ridge.
It runs from north to south under the Ocean.
This is at the boundary of four tectonic plates: Eurasian, North American, South American and African.
The ridge extends from Iceland in the north to about 58° south.
LA Times special Altered Oceans
Oceanography Image of the Day, from the Woods Hole Oceanographic Institution
NOAA In-situ Ocean Data Viewer  Plot and download ocean observations
www.cartage.org.lb
www.mnsu.edu
Mercury (mythology), the Roman god
Mercury (planet), the first planet from the Sun in our solar system
Mercury (element), the chemical element or atom
Project Mercury, the first human spaceflight program by the United States' NASA
Mercury (programming language), a programming language
Mercury automobile, a make of car owned by the Ford Motor Company
Mercury, France, a local government in the Savoie département of France
Bristol Mercury, a 9-cylinder aircraft engine
Freddie Mercury, singer of the group Queen
Mercury, also known as quicksilver or hydrargyrum, is a chemical element.
Its symbol on the periodic table is Hg, and its atomic number is 80.
Its atomic mass is 200.59.
The symbol Hg stands for its Latinized Greek name hydrargyrum, meaning watery or liquid silver.
No one has the credit for finding mercury.
It was known in ancient times.
Mercury was found in Egyptian tombs that are from 2000 BC.
Chinese people also knew it from long ago.
In China and Tibet, people thought using mercury would make them live longer and have better health.
One of China's emperors, Qín Shǐ Huáng Dì, is said to have been buried in a tomb with rivers of flowing mercury.
He died from drinking a mixture of mercury and powdered jade because he wanted to live forever.
However, this only made him die of liver failure, poisoning, and brain death.
The ancient Greeks used mercury in ointments.
The Egyptians and the Romans used it in cosmetics.
These cosmetics sometimes hurt and made faces uglier.
Mercury is a silvery-white liquid post-transition metal.
The reason for mercury being a liquid is complex.
It is heavy; a chunk of iron can float on mercury.
Compared to other metals, it does not conduct heat well.
However, it conducts electricity fairly well.
Mercury is the only metal with a known melting point (−38.83 °C) lower than caesium.
Mercury is one of the two elements that are liquids at standard temperature and pressure.
Bromine is the other one.
Mercury may be seen as a transition metal, but it is normally seen as a post-transition metal.
It is in Group 12 of the periodic table.
Mercury has seven stable (nonradioactive) isotopes.
202Hg is the most common isotope.
Mercury makes a blue to ultraviolet color in a tube when a spark is passed through it.
The ultraviolet light can kill germs or light fluorescent lamps.
Mercury is an unreactive metal.
It does not corrode in air unless hydrogen sulfide is also there, similar to silver.
Mercury can oxidize to mercury(II) oxide when heated in air.
If it is heated further, it decomposes into mercury and oxygen again.
It does not dissolve in ordinary acids, but can dissolve in oxidizing acids to make mercury salts.
It can make amalgams when mixed with most metals, like aluminium, gold, and zinc.
Iron, tantalum, tungsten, and platinum do not make amalgams with mercury.
Iron flasks were used to trade mercury because of this.
Mercury can dissolve large amounts of aluminium metal, making it dangerous to transport in aluminium containers.
The thin layer of oxide on aluminium stops it from amalgamating (making an amalgam with) aluminium, but the oxide coating can be damaged to expose the metal.
Then the aluminium metal is dissolved and oxidizes to aluminium oxide.
The aluminium oxide forms a solid and releases the mercury, which amalgamates more aluminium.
This process keeps repeating until a large amount of aluminium is dissolved.
Mercury forms chemical compounds in 2 oxidation states: +1 and +2.
Mercury(I) compounds are weak oxidizing agents and weak reducing agents.
Most of them are colorless.
They easily disproportionate to mercury(II) compounds and mercury metal.
They react with oxygen in the air to make mercury(II) compounds.
Many mercury(I) compounds do not dissolve in water.
Mercury(I) chloride is one of the most common mercury(I) compounds.
Mercury(II) compounds are strong oxidizing agents and very corrosive.
Mercury(II) compounds are red, yellow, or colorless.
Mercury(II) oxide and mercury(II) chloride are the most common mercury(II) compounds in the laboratory.
One thing they have in common is that they are all toxic.
The soluble ones are more toxic than the insoluble ones.
Mercury(I) compounds
Also known as mercurous compounds, these are weak reducing agents and weak oxidizing agents.
Most of them do not dissolve in water, making them less toxic than mercury(II) compounds.
Most of them are colorless or yellow.
Mercury(I) bromide, insouble white solid
Mercury(I) chloride, calomel, insoluble, white
Mercury(I) fluoride, light yellow
Mercury(I) iodide, a little soluble, unstable, yellow
Mercury(I) nitrate, very slightly soluble, white
Mercury(I) sulfate, light yellow solid
Mercury(II) compounds
Also known as mercuric compounds, these are strong oxidizing agents.
Most of them dissolve in water, making them very toxic.
They are colorless or red.
Mercury(II) bromide, white solid
Mercury(II) chloride, white solid, corrosive sublimate
Mercury(II) fluoride, white solid
Mercury(II) iodide, somewhat soluble, bright red
Mercury(II) oxide, orange, yellow or red, does not dissolve in water like most oxides
Mercury(II) nitrate, soluble, white, used to make hats
Mercury(II) sulfate, white solid
Mercury(II) sulfide, red solid
Organomercury compounds
These contain mercury reacted with a organic molecule.
They are even more toxic than other mercury compounds since they get absorbed very easily.
Dimethylmercury, colorless, extremely toxic liquid
Occurrence
Mercury is a rare metal.
It is about as common as silver.
Mercury is not expensive like silver because the mercury is very easy to get from the places where it is found.
Mercury can be found in elemental (liquid) form in nature, but this is not common.
Mercury as an element is the only liquid that is recognized as a mineral by  the International Mineralogical Association.
It is most often found in the form of cinnabar, a mercury(II) sulfide mineral.
The biggest deposits of cinnabar used to be found in Spain, but now are found in China.
It also occurs in other minerals like calomel, a mercury(I) chloride mineral.
China and Kyrgyzstan are the two main makers of mercury.
Mines in Italy, the United States, and Mexico have been closed.
China is opening more mines because the European Union wants to use fluorescent lights, which need mercury.
Mercury is made by roasting cinnabar in a furnace.
The sulfide is oxidized to sulfur dioxide, leaving mercury behind.
Uses of mercury
Medical uses
Mercury has been used in dental fillings until it was replaced with safer materials.
They are an amalgam of mercury with another element.
An organic mercury compound called thiomersal is used to preserve vaccines.
Merbromin, another organic mercury compound, is used as an antiseptic.
It has been banned in some countries like the US.
Mercury(I) chloride (also known as calomel or mercurous chloride) has been used as a diuretic, skin disinfectant, and laxative.
Together with other mercury compounds, Mercury(II) chloride (also known as mercuric chloride or corrosive sublimate) was used to treat syphilis.
The problem with this was that mercury(II) chloride is very toxic.
Sometimes the symptoms of its toxicity were confused with those of the syphilis it was believed to treat.
It is also used as a disinfectant.
Blue mass, a pill or syrup in which mercury is the main ingredient, was prescribed throughout the 1800s for different conditions such as constipation, depression, child-bearing and toothaches.
In the early 20th century, mercury was given to children once a year as a laxative and dewormer.
Teething powders for infants also had it in them.
Since the 1930s some vaccines have contained the preservative thiomersal.
In the body, this is changed to ethylmercury.
At first it was thought that this mercury-based preservative can cause or trigger autism in children, but scientific studies could not show such a link.
Because of this, thiomersal has been removed from most U.S. vaccines recommended for children six years of age and under.
There are certain exceptions to this rule for influenza vaccines.
In some cases, vaccines may still have very small amounts of thiomersal in them.
Cinnabar is still an important component of traditional Chinese, Tibetan, and Ayurvedic medicine.
Certain countries do not allow the use of mercury or its compounds in drugs.
For this reason, cinnabar has recently been replaced with less toxic products.
Today, the use of mercury in medicine has greatly declined in all respects, especially in developed countries.
Thermometers and blood pressure devices using mercury were invented in the early 18th and late 19th centuries, respectively.
Now their use is declining and has been banned in some countries, states and medical institutions.
In 2002, the U.S. Senate passed legislation to phase out the sale of non-prescription mercury thermometers.
In 2003, Washington and Maine became the first states to ban mercury blood pressure devices.
Mercury compounds are in some over-the-counter drugs, including topical antiseptics, stimulant laxatives, diaper rash ointment, eye drops, and nasal sprays.
The FDA has “inadequate data to establish general recognition of the safety and effectiveness” of the mercury in these products.
Mercury is still used in some diuretics, although other things can be used for most therapeutic uses.
In cosmetics, (thiomersal is widely used to make mascara.)
As a liquid electrolyte in a variant of the chloralkali process.
In mining, especially of gold and silver.
In mercury-vapor lamps and fluorescent lamps.
Certain  thermometers, barometers and manometers.
Because of its toxicity, it can be replaced by alcohol for most of these uses.
Certain electrical switches that turn on or off when tilted.
Mercury is liquid at room temperature, and fumes of mercury are very poisonous.
Ingested elemental mercury is less dangerous.
The biggest problems are organic mercury compounds which are eaten with food.
As with other heavy metals, inorganic compounds such as mercury(II) nitrate are also highly toxic by ingestion (eating) or inhalation (breathing in) of the dust.
Mercury can cause both chronic and acute poisoning.
In the year 1810, over 200 people died of mercury poisoning on the ship Triumph because a barrel of mercury had leaked.
Mercury is extremely poisonous and has to be used carefully.
When mercury is spilled, there are special ways to clean it up.
Smaller drops should be combined to a larger drop on hard surfaces to be removed more easily (for example, being pushed into a bag that can be thrown away).
Vacuum cleaners and brooms should not be used.
This is because they can spread mercury even more.
Afterwards, elements such as sulfur or zinc powder should be sprinkled over the place, then collected and cleaned away.
It is not easy to clean mercury entirely off clothing, so it is better not to use them anymore.
Breathing in mercury vapor is also very dangerous.
Mercury compounds
Africa is the second largest continent in the world.
It makes up about a fifth of the world's land.
It is surrounded by large areas of water.
There are 54 fully recognised and independent countries in Africa, and 14.7% (1.216 billion) of the world's population lives there.
It is thought to be the continent where the first humans evolved.
The history of Africa begins with the first modern human beings and continues to its present difficult state as a politically developing continent.
Africa's ancient historic period includes the rise of Egyptian civilization.
It also includes the development of other societies outside the Nile River Valley, and the interaction between these societies and civilizations outside of Africa.
In the late 7th century, North and East Africa were heavily influenced by the spread of Islam.
That led to the appearance of new cultures, like the Swahili people and the Mali Empire, whose king, Musa Keita I, became one of the richest and most influential people of the early 14th century.
This also led to an increase in the slave trade, which had a very bad influence on Africa’s development until the 19th century.
Slavery has long been practiced in Africa, just like the rest of the world.
But two new slave trades would create a much bigger and more violent version of slavery.
Between the 7th and 20th centuries, the Arab slave trade took 18 million slaves from Africa via trans-Saharan routes and the Indian Ocean.
Between the 15th and 20th centuries (a period of 500 years), the Atlantic slave trade took an estimated 7–12 million slaves to the Americas.
While some Africans collaborated with European and Asian slave traders, many were strongly opposed to slavery and avoided, protested, or fought it violently.
Africans who had been captured and sent to the French colony of Saint Domingue on slave ships played an important role in ending the Atlantic slave trade.
They began the Haitian Revolution, which created Haiti, the first country to permanently ban slavery.
After this revolution, European empires began to reduce slave trading and abolitionism became more popular.
Between 1808 and 1860, the British Navy captured approximately 1,600 slave ships and freed 150,000 Africans who were aboard.
In the late 19th century, the European powers occupied much of the continent, creating many colonial and dependent territories.
They left only two fully independent states: Liberia and Ethiopia (which the Europeans called “Abyssinia").
Egypt and Sudan were never formally made a part of any European colonial empire.
However, after the British occupation of 1882, Egypt  was effectively under British administration until 1922.
African independence movements had their first success in 1951, when Libya became the first former colony to become independent.
Modern African history is full of revolutions and wars, as well as the growth of modern African economies and democratization across the continent.
A civil war in the Democratic Republic of the Congo (formerly Zaire) began in 1998.
Neighbouring African countries have become involved.
Since the conflict began, it has killed an estimated 5.5 million people.
From north to south, Africa has most types of climate.
In sequence from the north:
Alpine and mediterranean climate
Dry sandy desert
Fairly dry savannah (grassland)
Rain forest
More grassland
More deserts
Running north-east to the south is the East African Great Rift Valley.
This has mountains, volcanoes, deep rifts and valleys, rivers and lakes.
In fact, Africa has examples of most of the Earth's climate types.
Much of North Africa is dry and hot: it is dominated by the Sahara Desert and does not receive much rain.
In Saharan Africa, there are few rivers or other water sources.
Underground water sources are very important in the desert.
These often form oases.
An oasis is an area of vegetation (plant life) surrounded by desert.
In that part of the world, the wind comes mostly from the east.
That does bring rain, but the Himalayas and the Tibetan Plateau block the monsoon rain and prevent it from getting to North Africa.
Also, the Atlas Mountains near the north coast
of Africa prevent rain from coming in from the north.
That is another rain shadow.
Conditions and winds are different further south, where huge amounts of rainfall near the equator.
The equator runs across the middle of Africa (see red line drawn on map).
That means much of Africa is between the two tropics:
Africa has a lot of wildlife.
There are many types of animals there.
In particular, it is now the only continent that has many native species of large mammals.
Some of them occur in very large numbers.
There are antelope, buffalo, zebra, cheetah, elephant, lion, giraffe, rhinoceros, apes, hyaena, and a lot more.
Over 2,000 types of fish live in African lakes and rivers.
The African Union (AU) is an international organisation.
It aims to transform the African Economic Community, a federated commonwealth, into a state under established international conventions.
The African Union has a parliamentary government, known as the African Union Government, consisting of legislative, judicial, and executive organs.
It is led by the African Union President and Head of State, who is also the President of the Pan African Parliament.
A person becomes President of the AU by being elected to the PAP and then gaining majority support in the PAP.
Extensive human rights abuses still occur in several parts of Africa, often under the oversight of the state.
Most of such violations occur for political reasons, often as a side effect of civil war.
Countries where major human rights violations have been reported in recent times include Uganda, Sierra Leone, Liberia, Sudan, Zimbabwe, and Côte d'Ivoire.
There are 54 UN member states in Africa.
Africa was the homeland for the first people.
People who come from Africa are called Africans.
People in the north are called North Africans and people in the south are called South Africans.
Languages in eastern Africa include Swahili, Oromo and Amharic.
Languages in western Africa include Lingala, Igbo, Hausa and Fulani.
The most popular language in Northern Africa is Arabic.
The most populated country in Africa is Nigeria.
Haiti: 98%
Saint Kitts and Nevis: 96.9%
Anguilla: 91.4%
Bahamas: 86.1%
Barbados: 81.1%
Jamaica: 76.3%
Dominican Republic: 71.1%
Cayman Islands: 60.0%
Trinidad and Tobago: 39.5%
Cuba: 34.9%
Turks and Caicos: 34.0%
Belize: 29.8%
Venezuela: 24.0%
Panama: 22.0%
Colombia: 21.0%
Brazil: 13-19%
United States: 12.9%
Puerto Rico: 6.9%
Argentina: less than 2%
African & Middle Eastern Reading Room from the United States Library of Congress
Africa South of the Sahara from Stanford University
The Index on Africa from The Norwegian Council for Africa
Aluka Digital library of scholarly resources from and about Africa
Africa Interactive Map from the United States Army Africa
The Story of Africa from BBC World Service
Africa Policy Information Center (APIC)
Hungarian military forces in Africa
News media
allAfrica.com current news, events and statistics
Focus on Africa magazine from BBC World Service
Butter is a dairy food.
It is made by moving the cream from whole milk for a long time.
The fat in the milk separates from the liquid.
The fat is butter.
Often, butter is made from cows' milk, butter can also be made from the milk of other mammals, like sheep, goats, bison, and yaks.
Salt, flavorings and preservatives are sometimes added to butter.
There are 717 calories in  of butter.
Cultured butter is a butter made from fermented cream.
Sweet cream butter is butter made from pasteurized fresh cream.
Raw cream butter is butter made from fresh or cultured unpasteurized cream.
Cooking fats
The Cold War was the tense fighting between the United States and its allies and the Soviet Union (also called the USSR) and its allies between the end of World War II and the fall of the Soviet Union.
It is called the "Cold" War because the Americans and the Soviet Union never actually fought each other directly.
Instead, they attacked each other in conflicts known as proxy wars where a powerful country starts a war that they don't fight in.
Conflicting countries
Most of the countries on one side were allied by NATO, whose most powerful country was the United States.
Most of the countries on the other side were allied by the Warsaw Pact, whose most powerful country was the Soviet Union.
The Western Bloc was the name of the capitalist countries led by the United States.
The North Atlantic Treaty Organization (NATO) is an alliance created in 1949 and included the United States, the United Kingdom, France, West Germany, Canada, Netherlands, Belgium, Luxembourg, Spain, Portugal, Italy, Norway, Denmark, Greece, and Turkey.
Other countries allied with the Western Bloc include Israel, Brazil, South Korea, Kenya (1960-1991), Bangladesh (1964-1968), Pakistan, North Yemen, Malaysia, Saudi Arabia, Philippines, South Africa, Australia and New Zealand.
The Eastern Bloc was the group of socialist countries led by the Soviet Union.
The Warsaw Pact was an alliance created in 1955 and included the USSR, Albania, Bulgaria, Czechoslovakia, East Germany, Hungary (until 1976), Poland, and Romania.
Other countries allied with the Eastern Bloc included Angola (1975–1991), Cuba, Bolivia, Cambodia (1977–1979), South Yemen, Tunisia, Nepal, Bhutan, Libya (1974–1991), Mongolia (1976–1988), Jamaica, North Korea, China and Laos (1975–1991).
In February 1917, Tsar Nicholas II of the Russian Empire was overthrown because people were unhappy with their living conditions (like being a serf), especially during World War I. The new government in Russia was a democratic socialist government.
Unfortunately, it was ineffective, and people were still unhappy.
In November 1917, a communist group called the Bolsheviks, led by Vladimir Lenin, overthrew the new government and were supported by groups of workers called Soviets.
The Bolsheviks created a new communist government called the Russian Soviet Federation Socialist Republic (also called simply Soviet Russia or the Russian SFSR).
However, not everyone supported the communists.
Many countries that had been part of the Russian Empire had left, such as Latvia, Lithuania, Estonia, and Belarus.
The Russian Civil War began, with the Soviet Russian Red Army fighting against the White Army of anticommunist Russians.
The White Army was not very united or organized.
The Allied Powers of World War I, such as the United States, the United Kingdom, and France, invaded Russia to support the White Army and stop the Red Army.
The Red Army eventually won the war in 1922, and established the Union of Soviet Socialist Republics (also called the Soviet Union), along with the newly-formed Socialist Republics of Ukraine, Armenia, Azerbaijan and Georgia.
The start of the Cold War in 1947 was caused by a belief that all governments would become either communist or capitalist.
The Western Allies feared that the Soviet Union would spread communism to the rest of Europe and was very concerned that Soviet agents had learnt how to make atomic bombs after the war.
Both nations had opposed Nazi Germany although the United States worked with Nazi scientists and Soviet Union had chosen not to fight with Germany in the Molotov-Ribbentrop pact and the two occupied Poland in 1939.
However, Germany turned against the Soviet Union in June 1941 and invaded it during Operation Barbarossa.
After World War II
After World War II, Germany was left in ruins.
The victorious Allies that occupied it split it into four parts.
in the western half of Germany, one part was given to the United States, one to the United Kingdom, and one to France.
The eastern half was occupied by the USSR.
The city of Berlin was also split among the four countries even though it was entirely within the eastern half.
The Federal Republic of Germany (Bundesrepublik Deutschland or BRD), or West Germany, was recognized by the Western Allies in June 1949 and was a capitalist democracy.
West Berlin was considered a part of the country.
The Soviets named their section of Germany the German Democratic Republic (Deutsche Demokratische Republik or DDR), or East Germany, later in 1949; it was a communist dictatorship.
From April 1948 to May 1949, the Soviets blockaded West Berlin to prevent the city from using West Germany's currency.
The United States and its allies supplied the city by airplanes until September 1949 in what became known as the Berlin Airlift.
Many East Germans wanted to live in West Germany for having greater quality of life and political freedom.
In 1961, the East German government built the Berlin Wall, dividing the two halves of the city, and heavily guarded it to prevent more people from escaping to the west.
The wall was considered a symbol of the Cold War and the Iron Curtain that divided Europe.
Espionage, or "spying," has been around for a long time and was very important during the Cold War.
After its successful nuclear espionage in the Manhattan Project, the Soviets created their spy organs, especially the KGB.
The CIA led Americans efforts abroad, and the FBI led counterespionage.
Catching foreign spies and fighting domestic subversion  were KGB functions.
In 1953, the Soviet leader Joseph Stalin died, and Nikolai Bulganin and Nikita Khrushchev took his place.
Khrushchev later took sole control of the Soviet Union.
Khrushchev's Secret Speech marked a period of de-Stalinization, and Khrushchev tried to undo many of the things done by Stalin (such as the Gulag prisons and Stalin's cult of personality).
In the United States, there was a "Red Scare", and when the Soviets detonated their own atom bomb, there was a big political fallout and the United States government made everybody scared about communists.
Famous people in many fields who had been Communist sympathizers like in the past like Larry Adler lost their positions.
Many actors were 'blacklisted' and so were not hired to act in movies, which ruined their careers.
US Senator Joseph McCarthy was believed by many when he accused some important Americans of being communists, including some high government officials.
The 1950s were the beginning of the Space Race between the United States and the Soviet Union.
It began with the Soviets putting the Sputnik 1 satellite into orbit around the Earth as the first country in space.
The United States responded by starting NASA and soon sent up its own satellites.
The Soviets also sent the first man (Yuri Gagarin) into Earth orbit and claimed that proved communism to be the better ideology.
In the 1950s, the United States (under President Dwight Eisenhower) created a policy called "New Look" to cut defense spending and to increase the number of nuclear weapons as a deterrent in order to prevent the Soviet Union from attacking the West.
The Soviets also increased their nuclear force, which resulted in mutual assured destruction.
In the Suez Crisis of 1956, the Cold War alliances were broken in an important way for the first time with the Soviet Union and United States favoring one side and Britain and France the other.
The Western Allies also decided to let Soviet troops suppress the Hungarian Revolution of 1956.
US Vice-President Richard Nixon engaged in several talks with Khrushchev during the 1950s.
One of these was the 1959 "Kitchen Debate" in a model kitchen in Moscow.
The debates highlighted the political and economic differences between the Americans and the Soviets.
The following year, the United States U-2 spy plane crashed in the Soviet Union.
Tensions between the two countries increased.
Cuban Missile Crisis (1962)
After the United States had invaded Cuba and failed in the Bay of Pigs, the Soviet Union attempted to supply Cuba with nuclear missiles.
The missiles in Cuba would have allowed the Soviet Union to target almost the entire United States effectively.
In response the United States sent a large number of ships to blockade Cuba to prevent the Soviet Union from sharing the weapons.
The United States and Soviet Union agreed that the Soviet Union would no longer give nuclear weapons to Cuba if the United States didn't invade Cuba again.
That was the highest period of tension during the Cold War and was the closest the world came to a nuclear war, with possible global conflict to follow.
Détente (1962–1981)
After the agreement that ended the Cuban Missile Crisis, relations between both sides eased up.
Several treaties, designed to reduce the number of nuclear weapons, were signed.
In 1964, the US under President Lyndon Johnson invaded North Vietnam, which resulted in a humiliating defeat for the Americans and South Vietnam in 1975.
During this period of détente, the United States began building a good relationship with the People's Republic of China, which had once been an ally of the Soviet Union.
The policy of détente ended in 1981, when US Pesident Ronald Reagan ordered a massive military buildup to challenge Soviet influence around the world.
The United States began to support anticommunists all over the world with money and weapons.
The idea was to help them overthrow their communist governments.
The Soviets had a slow economy during this decade because military spending was at an all-time high.
They tried to keep up with the United States in military spending but could not do so.
In the Soviet war in Afghanistan, which started in 1979, the Soviets had a difficult time fighting resistance groups, with some of them armed and trained by the United States.
The Soviets' failed invasion of Afghanistan is often compared to the American failure during the Vietnam War.
In the late 1980s, the new Soviet leader, Mikhail Gorbachev, made an effort to make an ally of the United States to fix world problems caused by the war, with the ultimate aim of eliminating nuclear weapons.
However, that did not take place because Reagan insisted on having a nuclear missile defense system.
The people of the Soviet Union were divided.
Some wanted Gorbachev to fight harder to eliminate nuclear weapons, but others did not want him to be talking to the United States at all.
The mixed feelings created an atmosphere of political infighting, and the people were no longer united behind one goal.
Also, the Communist Party started to crumble.
After the fall of the Berlin Wall in 1989 and without communist rule holding together the countries that comprised the Soviet Union, it was divided into smaller countries in 1991 like Russia, Ukraine, Lithuania and Georgia.
Eastern Europe got very poor and broken and returned to capitalism.
The Cold War was over.
Not all historians agree on when the Cold War ended.
Some think it ended when the Berlin Wall fell, but others think it ended when the Soviet Union collapsed in 1991.
Cold War -Citizendium
Mainland China, also called the Chinese Mainland, is the part of China not including the Republic of China controlling Taiwan, Kinmen, Matsu, and the Pescadores.
The term also excludes Hong Kong and Macau.
In the Qing Dynasty (Manchu Dynasty), all of Mainland China, Hong Kong, Macau, Taiwan, Kinmen, Matsu, the Pescadores, and Mongolia were part of the Manchu Empire.
Taiwan, Hong Kong, and Macau were colonized by foreigners for some years (Taiwan to the Japanese, Hong Kong to the British, and Macau to the Portuguese).
By the end the Qing Empire, China became Nationalist China (the Republic of China) and it got Taiwan back in 1945.
After the Communists (the People's Republic of China) took over most of China, the Nationalists kept only Taiwan, Kinmen, Matsu, and the Pescadores.
Mongolia became an independent state later.
Since then, Communist China only includes the part on the continent (mainland) and some small islands that are very near (the largest communist island is Hainan).
This region is Mainland China.
A capital city, or capital town or capital, is a city or town, specified by law or constitution, by the government of a country, or part of a country, such as a state, province, or county.
It usually serves as the location of the government's central meeting place and offices.
Most of the country's leaders, embassy and officials work in the capital city.
This doesn't have to be the case though: Monaco, Nauru, Switzerland and Vatican City are examples of countries that do not have a capital city.
Israel said Jerusalem was its capital: Most countries don't recognise this, and most embassies are in Tel Aviv.
In Japan, the city of Tokyo, which was the capital, was disbanded in 1943.
Today, the 23 city districts (called wards) have the role of capital city.
Each district is a city of its own, though.
Capitals are usually among the largest cities in their regions and often are the biggest.
For example, Montevideo is Uruguay's capital and its biggest city.
The capital may also be the most important center of commerce, as in London or Bangkok.
However, a capital is not always the largest city in a country.
For example, the capital of India is New Delhi, which is smaller than Mumbai.
In countries with subdivisions like the United States, the capitals of the federated states are often not the biggest cities.
For example, New York City is the biggest city in the United States and in New York State, but is not the capital of either.
The capital the country is Washington, DC, and the capital of the state is Albany.
An unusual case exists in Canada since the federal capital, Ottawa, is not the largest city in its province, Ontario, which is Toronto.
However, Toronto is the capital of Ontario, so Toronto is a provincial capital but not a federal one.
Some countries have more than one capital for different purposes.
For example, Bolivia has two (Sucre and La Paz) and South Africa has three (Pretoria, Cape Town, and Bloemfontein).
In a city-state like Singapore, Monaco, and the Vatican City, the capital is the country.
Not all countries have capitals.
Nauru is a country that does not officially have a capital, but the district of Yaren, which is where the government is, can be called the de facto capital.
Also, although many people consider the city of Bern in Switzerland to be the capital of the country, it is by law not the capital but the "federal city."
Capitals can be in cities that are already there like Athens or Rome, or a new town can be built and made the capital like Canberra and Alexandria.
Countries can change capitals from time to time.
Several cities have been the capital of China.
The United States once had its capital in Philadelphia and later in New York City but moved to the new city of Washington, D.C. in 1800.
Rio de Janeiro was the capital of Brazil until the new city of Brasilia was built between 1956 and 1960.
Reykjavík, the capital of Iceland, is the world's northernmost capital city.
Seat of government
Most countries have their seat of government within their capital.
However, Malaysia has its capital at Kuala Lumpur, but its seat of government is at Putrajaya.
In the Netherlands, the constitution calls Amsterdam the capital, but the seat of government is The Hague.
Climate means the usual condition of the temperature, humidity, atmospheric pressure, wind, rainfall, and other Meteorology|meteorological Weather|elements in an area of the Earth's surface for a long time.
In simple terms climate is the average condition for about thirty years.
Climate and weather are different.
Weather is the day to day conditions in the atmosphere.
The types of climates are: Tropical, Desert/dry, Temperate, Polar, Mediterranean.
Polar climate (also called boreal climate), has long, usually very cold winters, and short summers.
Temperate climates have four seasons.
Some of the countries which have a temperate climate are: most of the European countries.
Deserts.
They just have one or two seasons such as: Saudi Arabia and most of the African countries.
Tropical climates have warm temperature and only two seasons; wet and dry.
An example of a place with a tropical climate is the Amazon Rainforest in Brazil.
The Mediterranean climate is usually hot and dry in summer, and is cool and wet in winter.
An example of a country with a Mediterranean climate is Spain.
The latitude, ground, and height can change the climate of a location.
It is also important to note if oceans or other large bodies of water are nearby.
Climates are most commonly classified by temperature and precipitation.
The most commonly used classification was the Köppen climate classification, first made by Wladimir Köppen.
The Thornthwaite system, which was used from 1948, not only uses temperature and precipitation information, but evapotranspiration too.
This makes it useful for studying how many different kinds of animal species there are, and about the things that could happen when climates change.
The Bergeron and Spatial Synoptic Classification systems focus more on where the air masses which help make climates come from.
Climates can change after a long time.
Nowadays people are making the world warmer.
Rock often deforms in such a way that it bends instead of breaking.
This is called a fold.
The term fold is used in geology when one or a stack of originally flat, level surfaces, such as sedimentary strata, are bent or curved as a result of pressure and high temperature.
The basic cause is likely to be some aspect of plate tectonics.
When two forces act towards each other from opposite sides, rock layers are bent into folds.
The process by which folds are formed due to compression is known as folding.
Folding is one of the endogenetic processes; it takes place within the Earth's crust.
Folds in rocks vary in size from microscopic crinkles to mountain-sized folds.
They occur singly as isolated folds and in extensive fold trains of different sizes, on a variety of scales.
A set of folds distributed on a regional scale constitutes a fold belt, a common feature of orogenic zones.
There are large-scale and small-scale folds.
Large-scale folds are found mainly along a collision boundary between two tectonic plates.
Structure of a fold
The upfold is called an anticline.
The downfold is called a syncline.
symmetrical fold: two limbs are of equal steepness
Asymmetrical fold: one limb is steeper than the other
Overfold: one limb is pushed over the other
Recumbent fold: two limbs are nearly parallel
Overthrust fold: compressional force is so great that the rock strata are broken and slide over the other.
Formation of a fold mountain
Large depressions called geosynclines form between plates.
Seas filled the geosynclines and rivers flowing into them carried sediments (sand and silt) which build up on the sea bed.
Landforms formed by folding
Large-scale folding will develop parallel ranges of round-top mountains along destructive plate boundaries.
These mountains are known as fold mountains.
Magma under the crust is under very great pressure.
When folding and faulting occur, cracks or fractures appear.
These are lines of weakness.
When these lines of weakness develop downward in the crust and reach the magma, they will release the pressure in the magma.
This allows magma to rise up along the lines of weakness and intrude into the crust.
Some magma may even reach the Earth's surface as lava.
Volcanoes are the places where magma reaches the earth's surface.
The type of volcano depends on the location of the eruption and the consistency of the magma.
Intrusive volcanism is when magma is forced into the rocks that make up the Earth's crust.
When it cools and become solid while still underground, different features called plutons are formed.
The rock formed is intrusive igneous rock.
Batholiths: Have large scale magma that has been solidified at the base of the mountain.
Dyke: Is a small scale magma cooled within the earths crust that stands vertically to the existing rocks.
Sill: Is a small scale magma cooled near the earths surface that lies horizontally to the existing rocks.
Laccolith: A small scale magma that pushes the overlying layers of rocks to form a dome shaped structure.
Extrusions
Gas - sulphur, hydrogen, carbon dioxide and hot steam (geysers).
When uprising magma decreases in pressure suddenly, gases within magma explode to the Earth's surface and cause destruction.
Solid - pyroclast.
Mainly composed of: country rock, fragments of solidified lava and fine materials (volcanic ash and dust).
It can be classified by size into volcanic bombs, volcanic blocks, lapilli, volcanic ash and volcanic dust.
Liquid - lava, hot springs.
Caldera: a large depression in a former volcanic site.
When it is filled with water it is called a 'caldera lake'.
Composite cones: a large volcanic mountain formed by solidified lava on the surface.
Geysers: eruption of hot water and steam shooting into the air at regular intervals.
Hot springs: springs of hot water that flow out continuously without shooting up into the air.
The Pacific Ocean is the body of water between Asia and Australia in the west, the Americas in the east, the Southern Ocean to the south, and the Arctic Ocean to the north.
It is the largest named ocean and it covers one-third of the surface of the entire world.
It joins the Atlantic Ocean at a line drawn  south from Cape Horn, Chile/Argentina to Antarctica, and joins the Indian Ocean at a line drawn  south from Tasmania, Australia to Antarctica.
As the Atlantic slowly gets wider, the Pacific is slowly shrinking.
It does this by folding the sea floor in towards the centre of the Earth - this is called subduction.
This bumping and grinding is hard so there are many earthquakes and volcanoes when the pressure builds up and is quickly released as large explosions of hot rocks and dust.
When an earthquake happens under the sea, the quick jerk causes a tsunami.
This is why tsunamis are more common around the edge of the Pacific than anywhere else.
Many of the Earth's volcanoes are either islands in the Pacific, or are on continents within a few hundred kilometers of the ocean's edge.
Plate tectonics are another reason which makes Pacific Ocean smaller.
EPIC Pacific Ocean Data Collection Viewable on-line collection of observational data
NOAA In-situ Ocean Data Viewer  plot and download ocean observations
NOAA PMEL Argo profiling floats Realtime Pacific Ocean data