ejaasaari/simplewiki-2025-04-01 huggingface dataset:
Galileo Galilei (15 February 1564 – 8 January 1642) was an Italian polymath. Galileo was originally going to be a doctor but became a tutor instead. He was a professor of mathematics and natural science in Padua and Pisa. People most remembered him today for his conflict with the Catholic Church of his day, which led to his trial for heresy by the Inquisition. Life. Galileo was born on 15 February 1564 in Pisa, Duchy of Florence. He was the eldest of five siblings. His father was Vincenzo Galilei, who was a scholar and a musician. In 1574, the Galilei family moved to Florence and he started his formal education in the Camaldolese monastery. Astronomy. Galileo was not the first person to build a telescope. He was the first person to publish his observations of astronomical objects through a telescope. He discovered that the Milky Way is made of many stars. He discovered that the Moon has hills. He discovered the first moons not counting our own moon, these are the four biggest moons of Jupiter: Io, Europa, Ganymade and Callisto. Those moons are now called the Galilean moons. He discovered sunspots, which are dark areas of the Sun. He saw that the planet Venus has light and dark phases just like the Moon. This helped people to know that the Sun is at the center of the Solar System, as Nicolaus Copernicus had said. Physics. Galileo worked more at physics than at astronomy. He studied natural forces, and was one of the most important discoverers of the part of physics that is now called kinematics, including the discovery of the kinematic principle of relativity. However, he is often remembered now for things that either did not happen, or failed. A legend says that he climbed the Leaning Tower of Pisa, and dropped cannonballs of different weights, to see which would strike the ground first. Even though their weights were not the same, they hit the ground at the same time. Galileo found that objects fall to the ground at the same rate, unless things like wind resistance change the rate
When a person agrees to do something or to "not" do something, that person is making a promise. A promise can be made verbally (by saying it), or it can be written down as a contract. "Breaking" a promise, or not keeping it, is often just bad manners, but it can sometimes be illegal, such as when a contract is not kept. A vow is a special promise. It is mostly used in a religious sense or in ceremonies such as marriages when the couple who are being married make their "marriage vows", promising to be faithful to one another. An oath is a promise in the legal sense. When someone has to give evidence in a court of law they "swear an oath". This means that they promise they will tell the truth.
A cloud is water vapour in the atmosphere (sky) that has condensed into very small water droplets or ice crystals that appear in visible shapes or formations above the ground. Water on the Earth evaporates (turns into an invisible gas) and rises up into the sky. Higher up where the air is colder, the water condenses: it changes from a gas to drops of water or crystals of ice. We see these drops of water as clouds. The drops fall back down to earth as rain, and then the water evaporates again. This is called the "water cycle". The atmosphere always has some water vapour. Clouds form when the atmosphere can no longer hold all the invisible air vapor. Any more water vapor condenses into very small water drops. Warm air holds more water vapor than cool air. So if warm air with lots of water inside cools, it can form a cloud. These are ways air can cool enough to form clouds: Clouds are heavy. The water in a cloud can have a mass of several million tons. Every cubic metre (m3) of the cloud has only about 5 grams of water in it. Cloud droplets are also about 1000 times heavier than evaporated water, so they are much heavier than air. They do not fall, but stay in the air, because there is warm air all round the heavier water droplets. When water changes from gas to droplets, this makes heat. Because the droplets are very small, they "stick" to the warm air. Sometimes, clouds appear to be brilliant colors at sunrise or sunset. This is due to dust particles in the air. Cloud classification. Clouds are classified according to how they look and how high the base of the cloud is in the sky. This system was suggested in 1803. There are different sorts of clouds because the air where they form can be still or moving forward or up and down at different speeds. Very thick clouds with large enough water droplets can make rain or snow, and the biggest clouds can make thunder and lightning. There are five basic families of clouds based on how they look: The following is a summary of the main cloud types arranged by how high
The water cycle, or hydrological cycle, is the cycle that water goes through on Earth. Overview. Water is essential for life as we know it. It is present throughout the Solar System, and was part of the Earth from its formation. The source of the water was the same as the source of the Earth's rock: the cloud particles which condensed in the origin of the Solar System. Processes. This is the process that water starts and ends in the water cycle.
Water vapor is water that is in the form of a vapor, or gas. It is a part of the water cycle. When liquid water is heated to boiling point, 100 °C (212 °F), it turns into vapor. Water vapor can also be produced directly from ice; this is called sublimation. Steam is water vapor, but clouds are liquid water. The amount of water vapor in air is called humidity and it affects weather conditions. In the cold, breathing out causes the water vapor in the breath to freeze. Water vapor weighs less than air, thus slightly reduces the lift produced by an aircraft wing. It is also transparent, which means the small droplets that look like mist are actually liquid. Water vapor also is a big cause of the greenhouse effect. It is invisible, but makes visible water when it condenses.
Solid is one of the four common states of matter. The molecules in solids are closely bound together, so they can only vibrate. This means solids have a definite shape that only changes when a force is applied. This is different to liquids and gases which move randomly, a process called flow.  Solids can resist forces applied to their surface.  When a solid becomes a liquid, this is called melting. Liquids become solid by freezing. Some solids, like dry ice, can turn into gas without turning liquid first. This is called sublimation. Kinds of solids. The forces between the atoms in a solid can take many forms. For example, a crystal of sodium chloride (common salt) is made up of ionic sodium and chlorine, which are held together by ionic bonds. In diamond or silicon, the atoms share electrons and make covalent bonds. In metals, electrons are shared in metallic bonding. Some solids, like most organic compounds, are held together with "van der Waals forces" coming from the polarization of the electronic charge cloud on each molecule. The dissimilarities between the types of solid come from the differences between their bonding. Metals. Most metals are strong, dense, and good conductors of electricity and heat. The mass of the elements in the periodic table, those to the left of a diagonal line drawn from boron to polonium, are metals. Mixtures of two or more elements in which the big component is a metal are known as alloys. People have been using metals for many purposes since prehistoric times. The strength and relialbility of metals has led to their widespread use in making of buildings and other things, as well as in most vehicles, many tools, pipes, road signs and railroad tracks. Iron and aluminium are the two most commonly used metals. They are also the most common metals in the Earth's crust. Iron is most commonly used in the form of an alloy, steel, which has up to 2.1% carbon, making it much harder than pure iron. Since metals are good conductors of electricity, they are valuable in electrical tools and for carrying an electric current over long distances with little energy loss. Because of this,
Evaporation is when a liquid becomes a gas without forming bubbles inside the liquid volume. If bubbles are formed we are talking instead about "boiling". For example, water left in a bowl will slowly disappear. The water evaporates into water vapor, the gas phase of water. The water vapor mixes with the air. The opposite of evaporation is condensation. When the molecules in a liquid are heated, they move faster. This makes them full of energy and so the particles collide with each other, and eventually they become so far apart that they become a gas. Differences between evaporation and boiling. During evaporation only the molecules near the liquid surface are changing from liquid to vapor. During boiling the molecules inside the volume of the liquid are also changing to vapor. For this reason during evaporation no bubbles are formed, instead they are formed during boiling. Evaporation can happen at any temperature, while boiling happens only at a specified temperature called the "boiling point". Evaporation happens slowly, but boiling happens quickly. Rate of evaporation. Some liquids evaporate more quickly than others. There are many factors that affect the evaporation rate. The rate of evaporation depends on the liquid's exposed surface area (faster when increased), the humidity of surroundings (slower when increased), the presence of wind (faster when increased) and the temperature (faster when increased). Liquid with high boiling points (those that boil at very high temperatures) tend to evaporate more slowly than those with lower boiling temperatures. Evaporation is a very essential part of the water cycle.
A contract is an agreement or promise that the law can enforce. The law will enforce some agreements but not others. For example, in most places, if a parent promises to take a child to get ice cream, the law will not enforce that promise as a legal contract. The legal rules about which promises are enforced by the law can be different in different places (or jurisdictions), but a contract is usually enforced only if it is made by people or groups who want it to be enforced and who know what they are doing. Sometimes, a contract is written down and signed by the people agreeing to it, but it does not always need to be. People usually sign a contract when something important or costly is being done. For example, when people take a job, they will sometimes sign a contract with their employers. The contract will show what the person must do as part of his job, how much they will be paid, and so on. The person and the employer will sign the contract, and it will become a legal promise. If someone breaks a contract, another person might sue him or her. In a lawsuit about a contract, the court will look at the contract, listen to what the people who made the contract say about it, and then make a decision about what the contract means.
The face is a part of the body at the front of the head.  It is the part of us that others interact with. On the face are organs of sight, smell, hearing. Especially in a four-legged animal, the face is the part which goes first into the world, and that is why the sense organs and the mouth are there. In humans, the face includes the hair, forehead, eyebrow, eyelash, eyes, nose, ears, cheeks, mouth, lips, teeth, skin, and chin.
Kolkata (spelled Calcutta before 1 January 2001) is the capital city of the Indian state of West Bengal. It is the second largest city in India after Mumbai. It is on the east bank of the River Hooghly. When it is called Calcutta, it includes the suburbs. This makes it the third largest city of India. It is also known as city of joy It has 4,500,000 (4.5 million) people living in it. This also makes it the world's 8th largest metropolitan area as defined by the United Nations. Kolkata served as the capital of India during the British Raj until 1911. Kolkata was once the center of industry and education. However, it has witnessed political violence and economic problems since 1954. Since 2000, Kolkata has grown due to economic growth. Like other metropolitan cities in India, Kolkata struggles with poverty, pollution and traffic congestion. History. The discovery of the nearby Chandraketugarh, an archaeological site has proved that people have lived there for over two millennia. The history of Kolkata begins when the English East India Company arrived in 1690. Job Charnock, an administrator with the company is traditionally known as the founder of this city. However some academics say that Charnock is not the city's founder. At that time Kolkata, ruled by the Nawab of Bengal Siraj-Ud-Daulah, had three villages. They were Kalikata, Govindapur and Sutanuti. The British in the late 17th century wanted to build a fort near Govindapur. This was to become more powerful than Dutch, the Portuguese, and the French. In 1702, the British completed the construction of old Fort William, which was used to station its troops and as a regional base. Calcutta was declared a Presidency City, and later became the headquarters of the Bengal Presidency. When regular fights with French forces started, in 1756 the British began to upgrade their fortifications. When this was protested, the Nawab of Bengal Siraj-Ud-Daulah attacked and captured Fort William. This led to the infamous Black Hole incident. A force
A pencil is a kind of writing equipment that is also used to draw, usually on paper. Most pencil cores are made of graphite powder mixed with a clay binder. So, a pencil is usually made with a piece of graphite mixed with clay that has a wood case around it. The shape is usually a hexagonal prism but some pencils are square or cylinder. Colored pencils are a kind that do not use greyish silver graphite. Instead, the core is colorful. Colored pencils or crayons are usually meant for drawing rather than writing. The difference between pencils and pens. The important difference between pens and pencils is that the tip of a pencil is made of solid graphite (or other material) which is rubbed off onto the paper. A pen has a tip, usually made of metal, with liquid ink coming out and onto the paper. Writing with a pen can smudge when it is still wet. Writing from a pencil can be erased, but writing from a pen usually cannot, unless it uses a special type of ink and eraser. History.  An early writing tool was the reed pen used by ancient Egyptians, who wrote with ink on sheets of papyrus paper.  Another early writing instrument was the stylus, which was a thin stick of wood or metal, often lead. It was used for scratching onto black wax that covered white wood, a method used by the Romans. The word "pencil" comes from the Latin word which means "little tail". It is an invention of the 16th century in England. Discovery of graphite deposits. Some time before 1565 (it may have been as early as 1500), a large deposit of graphite was found in Borrowdale, Cumbria. The locals found that it was very useful for marking sheep. This deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. This is still the only large scale deposit of graphite ever found in this solid form. Chemistry was in its early stages and the substance was thought to be a form of lead. Consequently, it was called "plumbago" (Latin for "lead ore"). The black core of pencils is still referred to as "lead", even though
Logic is the study of reasoning. The rules of logic let philosophers make logical deductions about the world. Logic helps us decide whether something can be true or false.  Overview. Logic is often written in syllogisms, which are one type of logical proof. A syllogism is made from a collection of statements used to logically prove the final statement, called the conclusion. One popular example of a logical syllogism was written by the Classical Greek philosopher Aristotle: The conclusion is the final statement. This syllogism connects the first two statements to make a logical deduction: Socrates is mortal. The syllogism is made from three logical statements or propositions. These statements are short sentences describing a small step in a logical argument. The small statements make up the argument, the same way atoms make up molecules. When logic is correct, the statements are said to "follow" from each other. Statements have a truth value, meaning they can be proved to be true "or" false, but not both. Illogical statements or mistakes in logic are called "logical fallacies". Symbolic logic. Logical statements can be written in a special type of short hand writing, which includes the symbols of the symbolic logic. These symbols are used to describe logical reasoning in an abstract way. For instance: Here is the previous syllogism written in symbolic logic. formula_7 By replacing the English words with letters, one can make the syllogism even simpler.  formula_8 Similar to mathematical symbols for operations like addition and subtraction, symbolic logic separates abstract logic from the English-language meaning of the original statements. With these abstract symbols, people can study pure logic without the use of a specific written language. The syllogism is now written in the most abstract and simple way possible. Any distracting elements, such as English language words, have been removed. Anyone who understands logical symbolism can understand this argument. Logical proof. A logical proof is a list of statements put in a specific order to prove a logical point. Each statement in the proof is either an assumption made for the sake of argument, or has been proven to follow from earlier statements in the proof. All proofs must start with some assumptions
Communism is an idea in politics based on equality, that seeks a world without different social class groups. Communists believe these differences are extremely bad behavior by the powerful. They say that things like factories, tools and farms (the relations of production) are owned by the bourgeoisie, which gives them unfair power over workers. Communists want these things to be owned by the workers instead of the bosses. They believe this will bring about the end of all money and private property. This is the opposite to capitalism where there is money, and a state and class structure. In capitalism, there is a working class (people who don't own the means of production, also called the proletariat) and the owning class (people who own the means of production, sometimes called the ruling class or the bourgeoisie). Communist thinkers believe a communist world can happen if the working class take away the power of the bourgeoisie and start to control the means of production. Countries that officially follow forms of communism include Vietnam, China, Cuba and Laos, which are Marxist–Leninist, and North Korea, which follows Juche. The most famous communist thinkers were Karl Marx and Friedrich Engels; other prominent thinkers include Vladimir Lenin, Joseph Stalin, Leon Trotsky, and Mao Zedong. History. In 1848, Karl H. Marx and Friedrich Engels wrote "The Communist Manifesto". It was a short book with the basic ideas of communism. Most socialists and communists today still use this book to help them better and more accurately understand politics and economics. Many non-communists read it too, even if they do not agree with everything in it. Karl Marx said that for society to change into a communist way of living, there would have to be a period of change. During this period, the workers would govern society. This is called a dictatorship of the proletariat. Marx was very interested in the Paris Commune of 1870, when the workers of Paris ran the city after the Prussian Army defeated the French Army. He thought that this practical experience was more important than the theoretical views of the various radical groups. Many groups and individuals liked Marx's ideas. By the beginning of the twentieth century, there was a worldwide socialist movement
Resurrection means bringing someone back to life after they have died. Polytheistic religions. The idea of resurrection is found in writings of ancient polytheistic religions in the Middle East. Some Egyptian and Canaanite writings tell of gods being resurrected, such as Osiris and Baal. In Greek mythology, many men and women were given eternal life by being resurrected from the dead. In their stories, some who came back to life as gods were Alcmene, Castor, Heracles, and Melicertes. But the Greek philosophers at that time did not believe in a physical rebirth. Abrahamic religions. Christianity. Christians believe that Jesus Christ was resurrected. They also believe in resurrection for all people after they die. This is based on the Gospels and on Saint Paul's writings in the New Testament. The resurrection of Jesus is the Christian belief that he returned to life by a miracle. He died by crucifixion on Friday and rose from his tomb to new life on Sunday morning. This belief is celebrated at Easter. The resurrection of Jesus Christ is written about by the evangelists in the New Testament. They are the writers of the four Gospels in the New Testament. Christians believe the resurrection is a central part of the Christian faith. Jesus died on the cross to save mankind. When he was resurrected, Jesus defeated death. He is alive forever and sitting at God's right hand on a throne. This gives Christians the hope of a new life after death. This is because his resurrection mirrors the future for all Christians after they die. With Jesus Christ and with humans, the Bible shows that the resurrected body is changed from the original. This is because the human body, while alive, is weak and frail. But, the resurrected person lives for ever. All four Gospels tell about Jesus being raised from the dead. They also write about three times that Jesus brings a dead person back to life. However, these are not a true resurrection. These people were restored to a normal physical life. They later died a normal death, but a resurrected body is no longer mortal. Islam. In Islam, the Quran refers to a bodily resurrection of all those who have died
A monarchy is a kind of government where a monarch, a kind of hereditary ruler (someone who inherits their office), is the head of state. Monarchs usually rule until they die or pass down (when a monarch resigns it is called abdication). Most monarchies are hereditary, but some are elected. The most famous elected monarch is the Pope of the Roman Catholic Church. Some well known titles for monarchs are King, Queen, Emperor, Empress, Czar, Kaiser, Shah, Emir, Khan and Sultan. In less formal societies, the leader was often chosen by fighting. That was the way of warrior societies like the Zulu. Kings of England and Scotland were sometimes decided by battle. Warfare has been very frequent between human societies. "Wars of succession" is the general term for warfare caused by two or more individuals claiming the right of successor to a dead or deposed monarch. Many people who study government think a country should not have a monarchy. They argue that rulers ought to be elected, or that monarchs are often corrupt. Aristotle’s “Politics” compares the different forms of government which a state may have. He claims monarchy to be one of the worst regimes because one leader may be easily corrupted, even if they were selected as the most wise and deserving ruler of an entire group. Many people in countries such as the UK want to keep their royal family as they have remained a traditional icon and source of income for the country. However, in the UK their influence in the rule of the country is very small, leaving government to the governing political party elected by the people. This is because in a constitutional monarchy the monarch has only the power of head of state. History. Monarchy is one of the oldest kinds of government. Most historians agree that the first monarchies were tribes or small groups of people who decided to let a war-chief or other leader pass on their office to their children. This created a dynasty. Over time, the rules for deciding who got to become the next monarch became more complicated. Primogeniture is usually the oldest son or, in some countries, daughter, becomes the next monarch when the old one dies. Akkad and Sumer were the first recorded