juno-labs/simple_wikipedia huggingface dataset:
Time zone

**Time zones** give specific areas on the Earth a time of day that is earlier or later than the neighboring time zones. This is because when it is daytime on one side of the earth, it is night-time on the other side. There are 24 time zones dividing the earth into different times, each with its own name, like the North American Eastern Time Zone. The North American Eastern Time Zone contains large cities in North America like New York City and Miami.

Greenwich Mean Time (GMT) began in 1675. This was when the Royal Observatory, Greenwich was built to help ships find their longitude at sea. GMT was a standard reference for time keeping when each city kept a different local time. When railways began carrying many people quickly among cities keeping different time, they adopted time zones to simplify operations. By about 1900, almost all time on earth was in the form of standard time zones.

Greenwich Mean Time is now called UTC (Coordinated Universal Time). UTC is the time standard of the world. All other parts of the world are offset (plus or minus) according to their longitude. Most of the zones are offset by a full hour, but there are some offset by half an hour or 45 minutes.

In some parts of the world they follow the Daylight Saving Time (DST), and during this period of time in summer they add one hour to their normal solar hour.

In the poles, the time is UTC in the North Pole and UTC+12 in the South Pole.

The time zones are numbered in relation to the UTC, so in Los Angeles the time zone will be UTC−8, in London UTC+0, in Rome UTC+1, and in New Delhi UTC+5:30.
Market

A **market** is a place where people go to buy or sell things. When people have products to sell, they set up a **market place**. There may be a special building for the market place, or the market may be held in an open space where the sellers can put up a stall (like a kind of tent) and then take the stall down at the end of the day.

The word **"**market" can also have a more general meaning in the economy. It can mean the way things are bought or sold. "There is a big market for dishwashers" means that lots of people want to buy dishwashers. Therefore, a business that makes dishwashers is likely to be able to make a lot of money. When things are sold, people buy the product, and this "stimulates the economy" (helps people to spend and earn money). The market needs to balance supply and demand. There is no reason to make a supply of dishwashers if people do not want dishwashers. In the market, prices may change quickly if supply or demand changes.

## Competition

If a seller of a good cannot supply what customers want or asks for a very high price, other sellers may try to supply that good. If other sellers enter the market for that good, in competition, that will tend to fulfill demands and lower prices. Sellers who do not like competition may try to kill their competition. When there is no competition, a monopoly is formed. Many countries have laws to protect the free market from monopolies.

## Related pages

- Market forms
- Shop
Ambassador

An **ambassador** is a person sent by the government of a country to a different country. The ambassador is the official representative of their country.  The ambassador speaks to officials of the other country about any problems and issues between the two countries.

In past years, communication between countries could take days or weeks. It was necessary to have a person in each foreign capital to have meetings and make negotiations between countries. Nowadays, communication is much faster, and often governments can be in direct contact with each other.  However, it is still true that many problems need person-to-person meetings, so ambassadors are still needed.

Often an ambassador will live in the foreign country for a number of years. An embassy is where the ambassador lives. Embassies are most often in the capital of the foreign country. An ambassador may bring people with him to help him and work at the embassy. Some of the high ranking people may be called embassy officials.

It is both tradition and law that the ambassador and many embassy officials have diplomatic immunity. They cannot be arrested or prosecuted in the foreign country. The only possibility is to send a person back to their own country.

## Related pages

- Diplomacy
Monday

**Monday** is a day of the week. In some countries, it is the second day of the week. In other parts of the world, including some countries in Europe, Monday is the first day of the week.

Monday is the day in which is celebrated Easter Monday.

The International Standards Organization considers Monday the first day of the week.
Nuclear war

A **nuclear war** is a war in which countries fight with nuclear weapons. Because nuclear weapons are extremely powerful and could cause destruction throughout the world, the possibility of nuclear war has had a great effect on international politics.

So far, two nuclear weapons have been used during warfare. They were used in the atomic bombings of Hiroshima and Nagasaki and resulted in the deaths of approximately 120,000 people. Thousands of much more powerful bombs were made in later years.  They have not yet been used in war.

## History

Nuclear bombs were invented by the United States with Canadian and British help during World War II to help make that war stop.  The destruction of Hiroshima and Nagasaki and the Soviet invasion of Manchuria caused Japan to surrender.  They are still the only nuclear weapons that have ever been used in fighting a war.  At that time only the United States had the technology needed to make these bombs, but within a few years the Soviet Union had developed it too. In the new Cold War, the United States and the Soviet Union were enemies and each had many nuclear weapons, but they did not dare to use them against each other, either directly or by attacking the other country's allies. Since either country could be completely destroyed by the other's weapons, nuclear war could no longer be limited to the use of only one or two bombs; if they were used anywhere by one side, the other would attack with its own nuclear weapons, and the fighting would almost certainly become greater. This situation came to be known as the "balance of terror," or Mutually Assured Destruction, and stopped conflicts between the two superpowers from leading to a third world war.

Since the end of Communist rule in Russia and Eastern Europe, tensions between America and Russia have eased and war has become less likely. However, today there is more worry about nuclear proliferation. Countries around the world who already have their own bombs include Britain, France, China, Israel, India, Pakistan and North Korea; as all kinds of technology tend to become cheaper and easier to get and use, there is a fear that nuclear weapons could become available to countries with unstable governments. There is also the possibility that terrorists might be able to capture or build nuclear weapons and use them.  the threat of nuclear war is thought to have increased after the Russian invasion of Ukraine, as Russian threatened to use nuclear weapons during the invasion.

## Nuclear war in fiction

Ever since the end of World War II, writers, film-makers, and artists have created works of fiction imagining how a nuclear war might happen and what life would be like afterwards. Most have pictured widespread death and destruction, and a grim post-armageddon world where a few survivors struggle to live without power, medicine, or food. Some have pictured civilization breaking down completely, and primitive societies developing; with the past world becoming forgotten.

## Related pages

- World War III
Tax

**Tax** is money that people have to pay to the government.

The government uses the money it gets from taxes to pay for things. For example, taxes are used to pay for people who work for the government, such as the military and police, provide services such as education and health care, and to maintain or build things like roads, bridges and sewers. The earliest known taxes were those of the Egyptian Old Kingdom.

## Types of taxes

There are many different kinds of taxes. They may be direct tax or indirect  tax.
- Taxes that are based on how much money a company earns are called **corporate taxes**
- Taxes that are based on how much money a person earns are called **income taxes**.

- Taxes that are based on how much a person buys are called **sales taxes**.
- Taxes that are based on how much a person owns are called **property taxes**. Things like houses have a property tax on them.
- Taxes that are paid when official documents are approved are called **stamp duties** (because in the past the document would have a stamp put on it). Changing who owns a house will often need a document approving.
- Taxes that are paid when somebody dies are called **inheritance** or **estate taxes.**

Taxes can also be split into 3 groups:
- **Flat taxes**: Everybody pays the same percentage. Russia has a flat income tax and everybody in Russia has to pay 13% of the income.
- **Progressive taxes**: The more money a person makes, the higher percentage of their income they have to pay. Most countries have progressive income taxes.
- **Regressive taxes**: The less money a person makes, the higher percentage of their income they have to pay. Sales taxes are usually called regressive as poor people spend a higher percentage of their money than rich people.

## Paying lots of different taxes

Often because different parts of governments use taxes for different things, people end up paying lots of taxes.

In the United States, for example, the national government has an income tax; most states have an income tax or a sales tax, or both; and cities and towns may have a sales tax or a property tax. In some states such as Ohio, the sales tax is different in each county.

## Before Taxes

In ancient times, people from one city or area would attack another place, and make the people there pay _tribute_. Tribute meant that the attacked people would pay money (or other things), and the attacker would stop attacking them. A famous tribute was the Danegeld, when people from Denmark conquered part of England and made the English pay thousands of silver coins.

## Groups who are against taxes

Anarchists and Libertarians are against all taxes or against high taxes. As people are paying them unwillingly and under the threat of sanctions, they say that taxation is the same as robbery. (Taxation as theft)

## Related pages

- Income tax in the United States
- Tithe
Oboe

An **oboe** is a woodwind instrument with a double reed. It looks very similar to the clarinet, and may be confused with it. While the clarinet's shape remains cylindrical, the oboe's body is conical. The sounds produced by clarinets and oboes are very different. An oboe's sound is produced by blowing air through the double reed at the upper end of the instrument which forces the two reeds to vibrate together which produces the sound. The oboe has four parts: the bell, lower joint, upper joint, and the reed. A person that plays the oboe is called an oboist. A typical orchestra employs between two and four oboists, one of which also plays the cor anglais which sounds a fifth lower than the oboe. The oboe is part of a family of double reed instruments that includes the piccolo oboe, oboe d'amore, Cor anglais, bass oboe, and heckelphone.

The oboe came from the shawm which was a medieval and Renaissance instrument. It became popular in the Baroque period. Bach and Handel both used it in most of their orchestral music. Many Italian composers such as Antonio Vivaldi wrote concertos for the instrument, and it is used in a lot of chamber music. At this time it hardly had any keys, but over time more keys were added which made it easier to play the sharps and flats.

Later composers to write for the oboe as a solo instrument include Mozart, Weber, Richard Strauss, Vaughan Williams and Francis Poulenc.

The principal oboist in an orchestra plays the pitch A (440Hz) for the rest of the orchestra to tune their instruments to before a performance.

The name _oboe_ comes from the French language _hautbois_, meaning "high wood", a high-pitched woodwind instrument.
GURPS

The **Generic Universal RolePlaying System**, or **GURPS**, is a role-playing game system created by Steve Jackson Games. It emphasizes a set of rules that can be used in any time or world.  Characters are created using a point-based system.  There have been four releases of the GURPS core rules and dozens of game supplements that extend the core rules with genre or setting-specific information.

In 1990, GURPS became the focus of a Secret Service investigation when an as yet unreleased GURPS Cyberpunk game supplement was misconstrued by the Secret service as being a handbook for computer crime.
Eric Idle

**Eric Idle** (born 29 March 1943) is an English actor, comedian, composer, musician, singer-songwriter and writer. He is one of the members of Monty Python. Monty Python is a British comedy team.

Idle was born in South Shields, County Durham. He studied English at Pembroke College, Cambridge.

He is known for his songwriting and singing skills. His songs were important parts of the Monty Python television programme and movies. He wrote the song "Always Look on the Bright Side of Life". This song was written as the closing song of the 1979 movie Life of Brian.

He lives in Studio City, California.

## Infobox (person)

- **name**: Eric Idle
- **image**: Eric Idle 2012.jpg
- **caption**: Idle in 2012
- **birth place**: South Shields, County Durham, England
- **alma mater**: Pembroke College, Cambridge
- **occupation**: Actor, comedian, composer, musician, singer-songwriter, writer
- **years active**: 1967–present
- **notable works**: Monty Python, The Rutles, _Spamalot_
- **spouse**:

- **children**: 2
- **parents**: Ernest Idle
 Nora Barron Idle
Enemy

An **enemy** is a person or group of people who is against another person or group. In war, the enemy is anyone fighting for the other side of the war.

In the Bible, Saint Peter states that: ' your enemy, the Devil, roams around like a roaring lion looking for someone to devour' (1 Peter 5:8)
2000

**2000** (MM) was a century leap year starting on Saturday in the Gregorian calendar.  It was the last year of the 2nd millennium and the 20th century.

2000 was designated the International Year for the Culture of Peace and the World Mathematical Year.
Adelaide

**Adelaide** () is a city in Australia. It is the capital city of the state of South Australia, and it has an approximate population of 1.2 million people.

It is the fifth biggest city in Australia, behind Sydney, Melbourne, Brisbane and Perth. Adelaide was founded in 1836 by Colonel William Light, who named it after Queen Adelaide.

Adelaide is near the Southern Ocean and is north of the Fleurieu Peninsula. It has a river going through it called the River Torrens. Many festivals are held there. Adelaide has a hot-summer and cool-wet-winter Mediterranean climate. Grapes for wine production are grown in the Barossa Valley about 50 kilometres (30 miles) northeast of Adelaide, in the McLaren Vale about 30 kilometres south of Adelaide and parts of the Mt Lofty Ranges to the east.

## Other websites

- Adelaide Airport

## Infobox (australian place)

- **type**: city
- **name**: Adelaide
- **state**: sa
- **native name**: _Tarndanya_
- **image**: File:Adelaide montage.jpg
- **caption**: From top to bottom:
* A view of the Adelaide plains looking South towards the Adelaide Hills.
* The Torrens River at night with the Torrens river footbridge illuminated.
* Adelaide Oval during a cricket match with the Adelaide Oval scoreboard to the left and St Peter's Cathedral, Adelaide, St Peter's Cathedral to the right.
* Henley Beach, one of the beaches along the Adelaide coastline of the Gulf St Vincent, with the Henley Beach Jetty in the background.
- **pop**: 1324279
- **pop year**: 2016
- **poprank**: 5th
- **density footnotes**: (2011)
- **area**: 3257.7
- **force national map**: yes
- **timezone**: Australian Central Standard Time, ACST
- **utc**: +9:30
- **dist1**: 654
- **dir1**: NW
- **location1**: Melbourne
- **dist2**: 958
- **dir2**: West
- **location2**: Canberra
- **dist3**: 1161
- **dir3**: West
- **location3**: Sydney
- **dist4**: 1600
- **dir4**: SW
- **location4**: Brisbane
- **dist5**: 2130
- **dir5**: East
- **location5**: Perth, Western Australia, Perth
- **maxtemp**: 22.4
- **mintemp**: 12.3
- **rainfall**: 543.9
- **local map**: yes
- **zoom**: 8
Yoshi

**Yoshi** is a fictional dinosaur who appears in the _Mario_ series of video games made by Nintendo. The character was created by Shigeru Miyamoto.

Yoshi's best-known ability is his ability to eat enemies. He has a long tongue which he uses to eat enemies and items. In some games, after Yoshi eats enemies, they can be turned into eggs, which can be thrown. One of Yoshi's companions is Mario who helps Yoshi throughout dangerous situations. Most of the time, Mario can ride Yoshi.

Yoshi also can jump very high, and can also float in the air a little bit by kicking his legs. He can also ground pound enemies by quickly jumping on them.

Yoshis are usually green, but can come in many other colors. These other colors include green, red, light blue, blue, purple, pink, yellow, orange, brown, black, and white. Blue Yoshi is especially in Super Mario World. In _Super Mario 64 DS_, Rec Room there's a light blue color in one of Yoshi's minigames Tox Box. In Vs Mode multiplayer, it has a dark blue color and the third player can play him.

In a few games like _Super Mario World_ Yoshi gains powers, like flying, shooting fireballs when spat out, ground pounding, or all three by holding certain colored koopa troopa shells in its mouth.

Yoshi first appeared in the game _Super Mario World_ (SNES), which was released in 1990 in Japan and 1991 in the US and EU.

## Yoshi series

- Yoshi (video game)
- Yoshi's Cookie
- Yoshi's Safari
- Super Mario World 2: Yoshi's Island
- Yoshi's Story
- Yoshi's Universal Gravitation/Topsy Turvy
- Yoshi Touch & Go
- Yoshi's Island DS
- Yoshi's New Island
- Yoshi's Woolly World
- Yoshi's Crafted World

## Other appearances

- _Mario Kart 64_ (N64)
- _Mario Kart: Super Circuit_ (GBA)
- Mario Kart DS (DS)
- _Mario Kart Wii_ (Wii)
- _Mario Kart 7_ (3DS)
- _Mario Kart 8_ (Deluxe) (Wii U/Switch)
- _Mario Party_ series (N64, GCN, DS, and Wii)
- Super Mario 64 DS (DS) (Vs Mode multiplayer only, the one with the game card is Green Yoshi, others are Red, Blue, and Yellow Yoshi.
- _Super Mario Kart_ (SNES)
- _Super Mario Sunshine_ (GCN)
- _Super Smash Bros._ (N64)
- _Super Smash Bros. Melee_ (GCN)
- _Mario Kart: Double Dash!!_ (GCN)
- _Mario Power Tennis_ (GCN)
- _Super Mario Strikers_ (Wii)
- _Super Mario World_ (SNES)
- _Yoshi's Island_ (SNES), (GBA)
- _Yoshi's Island DS_ (DS)
- _Yoshi Touch & Go_ (DS)
- _Yoshi Topsy-Turvy_ (GBA)
- _Yoshi's Story_ (N64)
- _Yoshi's Woolly World_ (Wii U/3DS)
- _Yoshi's Crafted World_ (Switch)
- _Mario Strikers Charged_ (Wii)
- _Super Smash Bros. Brawl_ (Wii)
- _Super Mario Galaxy 2_ (Wii)
- _New Super Mario Bros. U_ (Wii U)
- _Super Mario Maker_ (Wii U/3DS)
- _Super Mario Maker 2_ (Switch)

## Reception

Yoshi is a very well-known character in the _Mario_ series. Yoshi is also seen a lot in Mario toys, games, and shirts. Yoshi was in two of the McDonald's Happy Meal Mario toy promotions, which only starred Mario, Donkey Kong and Yoshi himself. In a 2008 poll, Yoshi was voted as the third favorite video game character in Japan. Cloud Strife and Mario were second and first place, in that order.
Lake

A **lake** (from Latin: _lacus_) is a large body of water (larger and deeper than a pond) within a body of land. As a lake is separated from the ocean, it is not a sea. Some lakes are very big, and people in the past sometimes called them seas. Lakes do not flow like rivers, but many have rivers flowing into and out of them.

Most lakes on the surface of the Earth are fresh water and most are in the Northern Hemisphere. More than 60% of the lakes of the world are in Canada. Finland is known as _The Land of the Thousand Lakes_ (there are 187,888 lakes in Finland, of which 60,000 are large).

Many lakes are man-made reservoirs built to produce electricity, for recreation, or to use the water for irrigation or industry, or as drinking water.

If there are not rivers flowing out of the lake (see Endorheic basin), or they are few and small, the lake loses water only by evaporation or because the water flows through the soil pores. Where the water evaporates rapidly and the soil around the lake has a high salt level, as in very dry places, the water of the lake has a high concentration of salt and the lake is called a **salt lake**. Examples of salt lakes are the Great Salt Lake, the Caspian Sea, the Aral Sea, and the Dead Sea.

## Largest lakes by continent

- **Africa** - Lake Victoria, also the second largest freshwater lake on Earth. It is one of the Great Lakes of Africa.
- **Antarctica** - Lake Vostok.
- **Asia** - Lake Baikal is the largest lake that is completely in Asia. The Caspian Sea, the largest lake on Earth, is on the Europe-Asia border (an artificial border) and so both continents share this lake.
- **Australia** - Lake Eyre, that most of the time is without water; it takes water when it rains a lot.
- **Europe** - Lake Ladoga, followed by Lake Onega, both in northwestern Russia.
- **North America** - Lake Superior.
- **South America** - Lake Maracaibo but it is like a bay because it has a wide opening to sea. The largest freshwater lake of South America is Lake Titicaca, which is also the highest body of water on Earth at 3,821 m (12,507 ft) above sea level where boats can travel.

## Notable lakes

- The **largest** lake in the world by area is the Caspian Sea, with 394,299 km². The **largest freshwater** lake by area is Lake Superior (82,414 km²), part of the Great Lakes.
- The **longest** freshwater lake is Lake Tanganyika, with a length of about 660 km. Lake Baikal is the second longest (about 630 km from tip to tip).
- The **deepest** lake is Lake Baikal in Siberia, with a bottom at 1,637 m (5,371 ft). Lake Tanganyika (1,470 m) is the second deepest lake.
- The **highest** lake of the world is a small lake (pond) without a name on Ojos del Salado at 6,390 m (20,965 ft). But the highest navigable lake is Lake Titicaca in Peru and Bolivia at 3,812 m (12,507 ft).
- The **lowest** lake of the world is the Dead Sea, bordering Israel and Jordan at 418 m (1,371 ft) below sea level. It is also one of the lakes with highest salt concentration.
- Lake Enriquillo in Dominican Republic is the only saltwater lake in the world where crocodiles live.

## Related pages

- List of lakes
- Salt lake
French

**French** can mean:

- Something that is from or related to France
    - The French language
    - French people
    - French cuisine
- French kiss
East

**East** is one of the 4 main directions on a compass (called cardinal directions). East is normally to the right on most maps. For example: Japan is east of China, which is itself east of Pakistan. When “The East” is described: it usually refers to the countries of Asia (especially from Pakistan eastwards like China and India). The sun and moon rise in the east.
Population

A **population** is the number of living people that live together in the same place. A city's population is the number of people living in that city. These people are called **inhabitants** or **residents**. The population includes all individuals that live in that certain area. The world population was estimated to have reached 8 billion in November 2022. Asia is the most populous continent, with its 4.8 billion inhabitants being 60% of the world population. The most populous country is India with 1.4 billion people.

Population density is the average number of people in a place. Urban areas such as big cities have a high population density. People living there lives close to each other. In areas with a low population density, people usually live far away from each other, such as in rural areas out in the countryside.

Usually population refers to the number of humans in a certain area. The maximum population that can be supported in an area is called the carrying capacity.

## Population trends

Global population is going up, but the population growth rate is declining all over the world. Growth in poor countries is faster than in rich ones; some rich countries have a population pyramid that is nearly square. Urbanization is also common, and urban areas usually have lower birth rates. In population growth, births exceed deaths. In the modern world this is due to reduction of infant deaths, control of infectious diseases, and improved agriculture so more people can eat.

The change in population from 2010 to 2015 was:
- World: +420 million
- Africa: +146 million
- Asia: +223 million
- Europe: +3 million
- Latin America and Caribbean: +35 million
- Northern America: +14 million
- Oceania: +2.9 million

Human population control is the practice of altering the rate of growth of a human population. Concerns about overpopulation and its effects on poverty, environmental degradation, and political stability led to efforts to reduce population growth rates.

## Related pages

- Population density
- Population growth
- Human population planning
- Overpopulation
- Census

## Further reading

- Henderson, Kirsten, and Michel Loreau. "An ecological theory of changing human population dynamics." People and Nature 1.1 (2019): 31-43.
- YAN Kun(2011). The tendency equation of the population and its limit value in the United Kingdom (Brief annotation of the connection equation(R)), Xi'an: Xi'an Modern Nonlinear Science Applying Institute.
World war

A **world war** is an international conflict in which most of the countries in the world fight or help.

There have been two World Wars so far, World War I (1914-1918), and World War II (1939-1945),  Several earlier historical wars such as the Anglo-Dutch Wars were fought in many places around the world, but they were wars amongst European empires.

After World War II, many people were scared that  World War III would start from the Cold War between the United States and Western Bloc on one side and the Soviet Union and Eastern Bloc on the other.  After World War II, countries had many powerful weapons, including jet bomber airplanes, which could carry nuclear weapons to destroy many buildings and kill many people instantly, far away; and much faster missiles which could also carry nuclear weapons.
Snow

**Snow** is a form of ice. Snow forms when water in the atmosphere becomes frozen. It comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. Snow comes in all different shapes and sizes.

At the freezing point of water (0° Celsius, 32° Fahrenheit), snow melts and becomes liquid water. Sometimes, the snow will melt very fast and become water vapor. This is called sublimation. The opposite, where water vapor becomes snow, is called deposition.

Snow is used for some winter sport activities like skiing and sledding. Sometimes people make artificial snow so they can ski. People also commonly build things out of snow for fun.

Snow can also be dangerous, as it can lower visibility and make driving very difficult. When it snows, the snow will melt a little during the daytime and freeze again at night. This makes ice which can make driving conditions very treacherous. Snow plows are used to remove snow from roads to make driving easier and safer. Also, sand or salt may be added to the road to help tires grip the road. When salt is mixed with snow, the snow will melt more easily. This is because salt water has a lower melting point than fresh water (water without salt).

A blizzard is a dangerous type of a snowstorm. A blizzard produces strong winds that keep the snow in the air, thus reducing visibility. Sometimes it produce thunder snow, which is snow with lightning and thunder.
West

**West** is one of the 4 main directions on a compass. West is normally to the left on most maps. For example: (Germany is located to the west of Poland, which is itself located to the west of Lithuania). When “The West” is used in everyday speech: it usually refers to the nations of Europe (Especially from Croatia Westward) and its daughter states in the Americas and Australasia. The sun and moon also set in the west.
Agreement

An **agreement** is writing down a promise made. Agreements are common in law and business. For example, when a person takes out a loan or hires someone to work, an agreement is usually signed so that everyone understands what and when things must be done.

## Related pages

- Contract
- Treaty
Promise

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.
Water cycle

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.

- The cycle starts when water underground of the Earth evaporates. Evaporation means the sun heats the water which turns into a gas
- Then, water gathers as water vapour in the sky. This makes clouds
- Next, the water in the clouds gets cold. This makes it become liquid again. This process is called condensation
- Then, the water falls from the sky as rain, snow, sleet or hail. This is called precipitation
- The water sinks into the surface and also collects into lakes, oceans, or aquifers. It evaporates again and continues the cycle
- This whole process in which water evaporate and falls on the land and later flows back in river and pond is known as water cycle

## Human activities affecting water cycle

- Industry
- Agriculture
- Deforestation
- Dam construction
- Removing groundwater from wells
- Taking water from rivers

## Related pages

- Rock cycle
- Geophysics
- Hydrosphere
- Carbon cycle
- Coriolis effect
- Ecohydrology
Water vapor

**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 it 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.

## Properties of water vapor

Water vapor is the gas form of water (H₂O). In this state, the water molecules are no longer stuck together by hydrogen bonds like they are in liquid or ice. Instead, each molecule moves around freely on its own. A single water molecule is made of two hydrogen atoms and one oxygen atom. These atoms are joined by covalent bonds, meaning they share electrons. The shape of a water molecule looks like a bent "V". It has an angle of about 104.5° between the hydrogen atoms. Oxygen pulls more on the electrons, making one side of the molecule more negative and the other side more positive. This makes water a polar molecule.

In water vapor, the tiny water molecules move quickly and randomly, like other gases.  Each molecule is on its own, flying around freely. But because water molecules are polar (they have a positive side and a negative side), they can still weakly attract each other or other polar molecules in the air. These weak attractions can slightly change how water vapor behaves. This happens especially when there is a lot of water vapor or they are under high pressure. Still, in most everyday situations, water vapor acts almost like a regular or ideal gas.

People often think steam or mist is the same as water vapor, but that is not true. Real water vapor is actually invisible. You cannot see it with your eyes. What we call steam is actually made of tiny liquid water droplets floating in the air. These form when water vapor cools down and starts to condense. True water vapor, like the air we breathe, is a gas you cannot see. But even though it is invisible, we can still measure it using special tools. Water vapor has pressure, takes up space (volume), and has a temperature, just like any other gas.

In nature, water vapor is usually mixed in with other gases in the air. How much water vapor the air can hold depends on the temperature. Warmer air can hold a lot more water vapor than cooler air. That is why places near the equator are more humid. Water vapor is made of small, light molecules. Each water molecule has a mass of about 18 grams per mole, which is lighter than nitrogen (28) and oxygen (32), the main gases in air. This means that humid air is actually lighter than dry air. Because it is lighter, moist air usually rises up. This helps form clouds and plays a big role in weather.
Solid

**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, electrical power grids rely on metal cables to get electricity. Home electrical systems, for example, are wired with copper for its good conducting uses. The high thermal conductivity of most metals also makes them useful for stovetop cooking utensils.

### Minerals

Minerals are natural solids formed through many geological processes and having a crystal structure with uniform physical things throughout..

## Related pages

- Liquid
- Gas
- Plasma
Evaporation

**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.

## Related pages

- Boiling
Contract

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.

## Related pages

- Law
- Oath
Face

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.
Parliament

A **parliament** is a type of legislature.

The most famous parliament is probably the Parliament of the United Kingdom, which is sometimes called the "Mother of all Parliaments".  The word "parliament" comes from the French word _parler_, which means a talk.

The Althing, the national parliament of Iceland, was founded earlier (930 AD), so it is the oldest legislature in the world still existing. However, the Althing did not function as a legislature for four centuries, and its role as a _primary_ legislature is modern.

## Other parliaments

Other parliaments have copied the UK and work similarly. They have three levels - a lower house which makes the law, an upper house which reviews the law (Decides if they like it or not, and suggest changes to it), and a head of state who is mostly for show and who starts and ends each year of parliament. The Prime Minister is almost always the person whose party has the most seats, but if the lower house does not think he is doing a good job they can call a vote of no confidence and ask him to leave his job as Prime Minister or have an election.

## The word "parliament"

Sometimes people use the word "parliament" to describe a legislature, even if it is not a real parliament. A "parliament" is a type of legislature which has a Prime Minister.

## Similar to a congress

A parliament is a lot like a congress but a congress cannot ask the head of the government to leave his job. Also, a congress runs for a number of years according to the country's constitution, but a parliament can be stopped as long as enough members agree. Elections are held after this happens.

## Countries that have Parliaments

- Australia
- Austria
- Belgium
- Canada
- Ghana
- Germany
- Greece
- Iceland
- India
- Israel
- Italy
- Malaysia
- Moldova
- Netherlands
- New Zealand
- Pakistan
- Romania
- Russia
- Ukraine
- United Kingdom
- Bulgaria

## Related pages

- Constitution
- Constitutional economics
- Democracy
- Legal rights
Turing test

The **Turing test** is a test to see if a computer can interact with a person. The human should not be able to realize it is interacting with a computer.

Alan Turing thought that if a human could not tell the difference between another human and the computer, then the computer had shown intelligent behavior.

## Test setup

A person has a telegraph, and is connected to two communication partners. One of the two correspondents is a machine. The person can ask anything with the telegraph. If the person cannot tell which of the two is the machine more than 50% of the time, then the machine is said to be _intelligent_.

Later on, people narrowed down the test. A human is unlikely to know everything. Therefore, both the human and the machine would be specialists in some field of knowledge (and so would the person asking).

## Media

The comic strip Dilbert makes several mentions to the PHB (Pointy Haired Boss) failing the Turing test.

## Related pages

- AlphaGo
Fuel

A **fuel** is a substance that is changed in some way to produce heat, electricity, or other forms of energy. This is usually by being burnt in fire, although there are exceptions, such as nuclear fuel. Fuel can be divided into two main types: fossil fuels and other fuels.

## Fossil fuel

There are several kinds of fossil fuels:
- coal
- oil and products that are refined from oil (gasoline, diesel, kerosene)
- natural gas
Some people do not want us to use fossil fuels because they may pollute the environment. Because all fossil fuels are made out of carbon, burning them makes carbon monoxide and carbon dioxide. Too much carbon dioxide in the air causes a greenhouse effect. Carbon monoxide in the air is poisonous to humans and animals. Fossil fuels are also non-renewable, or renew extremely slowly (thousands to hundreds of millions of years). This means that we will eventually run out of fossil fuels.

## Other fuels

Other fuels are not made from fossils. Some of these, like nuclear and hydrogen, do not have carbon in them. Others, like wood or ethanol, do have carbon in them. Some examples of these fuels are:
- Nuclear fuel (uranium, plutonium, thorium, etc.)
- Hydrogen
- Biofuels from biomass
    - Firewood
    - Biodiesel (a diesel-type fuel made from plants)
    - Ethanol (made from grains or other plants)
These fuels are renewable. This means that we can make more of them if we run out. For instance, if we run out of ethanol, we can grow some more corn and make some more ethanol.

## Other websites

- Fuel -Citizendium
Index of Soviet Union–related articles

## Lists of people

- List of Premiers of the Soviet Union
- List of Russians

## A

- AK-47

## B

- Baltic states
- Bolshevik

## C

- Central Asia
- Cold War
- Constructivism
- Communism
- Communist Party of the Soviet Union
- Comrade
- Collective farming
    - Collectivisation in the USSR

## E

- Eastern Front (World War II)

## G

- Glasnost
- Great Soviet Encyclopedia

## H

- Hero of the Soviet Union
- History of the Jews in  Russia and Soviet Union
- History of the Soviet Union (1985-1991)
- Holodomor

## K

- Kolkhoz

## M

- Marxism–Leninism
- Moscow Metro

## O

- October Revolution

## P

- Palace of Soviets

## R

- Red Army
- Republics of the Soviet Union
- Russian Civil War

## S

- Socialism
- Soviet
- Soviet (council)
- Soviet people
- Soviet Union
- Soviet Union national bandy team
- Soviet Union national football team
- Soviet Union national ice hockey team
- Sputnik programme
- State Anthem of the Soviet Union

## V

- Volga Germans

## W

- Warsaw Pact Organization
- White movement
- World War I
- World War II
Comoving distance

In normal cosmology, **'comoving**' distance or **'proper distance**' is one of several distances measured by cosmologists to define distances between objects.

## Method

To talk about the shape of the Universe, scientists want to forget that the Universe is expanding. So they separate the shape from time and pretend that the Universe is not expanding. They remember that, really, the Universe is expanding, but they write this in a variable called the scale factor. Then, the distances they talk about, while putting the scale factor to the side, are called **comoving distances**. When they think about the Universe using comoving distance, they think of the Universe as not expanding. This way, some calculations are easier.

## Purpose

When the part of the Universe which we can see today started, it was very small. Everything in this part of the Universe was much closer together than today. It was also very hot and photons (particles of light) were moving in different directions. Light moves very fast, but the light speed is limited and the Universe was expanding very fast.

### Comparison

Think of two ants on the surface of an expanding balloon. One ant starts moving towards another, but the balloon itself is also expanding. After a long time the balloon starts expanding more slowly. Eventually one ant reaches another. That's like photons in our universe. Some of the light from the stars you see at night traveled for billions of years to reach your eye. Surprisingly, it started very close to where you were (or the atoms of which your body consists), but just could not keep up with the universe expansion. Of course, if something else started out very close to where you were, but was not traveling toward you, it would be very far away from you now because of the expansion.