Datasets:

cahya

/

simple-wikipedia

like 0

Open content is when someone creates something and lets others copy it or change it without having to ask for permission. Any media can be open content, from text and pictures to video and sound. When someone creates something (like a picture or book), they can make that work "open". This means that other people are allowed to copy it and change it if they want. Something that is open content may be free of charge, but it does not have to be. The Simple English Wikipedia is open content. So are other Wikipedias. If a person changes open content or makes new open content, everyone can give it to anyone else, or even sell it. It is never needed to ask permission to do this, because the people who wrote the text already gave their permission when they clicked the "save" button. License The rules that say how people can use, change and pass around open content are called a license. A license explains exactly what you are allowed to do with the content that falls under it. Licenses are often written in difficult language (legal jargon), but many licenses have summaries that are much easier to understand. The makers of open content get to choose what license to use for their work, and everyone else has to follow it. Only the maker, who owns the copyright, can change it to another license. Most open content licenses say that when others change the work, they must also declare it to be open and under the same license. This is called share-alike and means that anything based on work will always be open content. All the content in Wikipedia is open under the rules of the Creative Commons Attribution/Share-Alike License, a very well-known open content license. Another well-known open content license is the GNU Free Documentation License. Related pages Free software Author Open source Content license References Software Art Free content

Orthography is an official or correct way to write a particular language. It includes rules of spelling. Orthography may also include rules about punctuation, capitalization, and diacritics (e.g. accents). In English, spelling is a problem for all learners, and is the main issue in orthography. Some languages have someone to decide the correct spelling, such as the Académie française. English does not. English orthography was the work of the early printers. They had to decide how particular words would be spelled in their books. Gradually the number of alternative spellings began to drop. The word which is "merry" today was spelled in about 30 ways in written sources from the 9th to the 16th century.p970 English orthography English orthography, or English spelling, is the way the 26 letters of the alphabet are used to write down the 36 (IPA) sounds of English. The first manuscripts in Old English were written using the Latin alphabet. It had 24 letters.p16 Vowels No alphabet fits its language exactly. One reason for this is that there are always more sounds than letters. In English there are far more vowel sounds than vowels. The ancient Greeks, who were the first to use letters for vowels, decided to use only a few letters for their vowel sounds. This choice influenced all later alphabets: "The importance of the Greeks in the history of alphabetic writing is paramount. All the alphabets in use in Europe today stand in direct or indirect relation to the ancient Greek". English would need about 20 vowels to represent the vowel phonemes (~sounds) in common use,p237 and some languages do have more letters for vowels. The Georgian language has a total of 41 letters. A shorter alphabet works by using two or three letters for a single sound, or one letter for several sounds. Consonants The English alphabet has only three consonants which have one sound, cannot be produced by other combinations and are never silent: n, r and v. The English language uses 22 to 26 consonant phonemes. Dialects The other reason that alphabets never exactly fit languages is dialect. A spoken language varies from place to place and from time to time. This is very obvious with English, as the pronunciation is so different in different parts of the world. A written language will always be less flexible than its spoken parent. It has a different function, and is produced mechanically. It must serve everyone who speaks the language, and it does this by keeping the spelling similar from one time to another. Therefore, all alphabets have sounds which are difficult to represent with the letters in use. And English also has other problems: sounds that can be written in different ways, and spelling which can be pronounced in different ways. This all gives rise to problems of spelling. British and American English Differences between American English and British English spelling came about mainly as the result of one man. Noah Webster (1758–1843) wrote a Grammar, a Spelling book, and finally an American dictionary of the English language. In the course of this, he proposed a number of simplifications in spelling. In his dictionary, he chose s over c in words like defense, he changed the re to er in words like center, he dropped one of the Ls in traveler. At first he kept the u in words like colour or favour but dropped it in later editions. He also changed tongue to tung: that did not stick. His main reason was to help children learn to read and write. Webster's dictionary contained seventy thousand words, of which twelve thousand had never appeared in a published dictionary before. Webster did create a slightly different identity for American English. But, because his efforts did not address some of the most glaring problems, his variations make little difference to the way the language is used. An example of the real problems in English orthography is the word ending -ough, which is pronounced several different ways: tough, bough, cough... The root causes of spelling variation are historical. Loan words come with their own (foreign) spelling. Some French loan words are still spelled in the French way; others have been changed. English spelling reform has been proposed by many people since Webster, such as George Bernard Shaw, who proposed a new phonetic alphabet for English. In some cases Webster's changes have been widely adopted in Britain: the spelling programme came from the French; US program is clearly simpler, and more consistent with word endings in English. In our modern world, English orthography is still a problem. In some countries (notably, France) a national committee can give advice and direction as to spelling. English has long escaped from national custody. Spelling, though important, is less important than how the language is used in practice. The differences between British and American English in use are more to do with idiom, slang and vocabulary than they are to do with spelling. In this respect, spelling in writing or print is a bit like pronunciation in speech. They are the necessary outer clothes, but the inner substance is more important. In Wikipedia (note the spelling), articles may be in either American or British English, but should be consistent within each article. More details: Wikipedia:Manual of Style Dictionaries and phonetics Modern British spelling and use was greatly influenced by the two great English dictionaries, Samuel Johnson's A dictionary of the English language (1755), and James Murray's Oxford English Dictionary. Johnson's dictionary was hugely influential, abroad as well as at home. The dictionary was exported to America. "The American adoption of the Dictionary was a momentous event not just in its history, but in the history of lexicography. For Americans in the second half of the eighteenth century, Johnson was the authority on language, and the subsequent development of American dictionaries was coloured by his fame".p224 For American lexicographers, the dictionary was impossible to ignore: "America's two great nineteenth-century lexicographers, Noah Webster and Joseph Emerson Worcester, argued fiercely over Johnson's legacy ... In 1789 [Webster] declared that 'Great Britain, whose children we are, and whose language we speak, should no longer be our standard; for the taste of her writers is already corrupted, and her language on the decline.' ... Where Webster found fault with Johnson, Joseph Worcester saluted him ... In 1846 he completed his Universal and critical dictionary of the English Language.p226 Some people argue which language is the easiest to spell. People who learn a second language tend to think that their first (native) language is the easiest. However, for the learner, programmatic languages, with well-defined rules, are easier to start with than English. The spelling of the English language is by far the most irregular of all alphabetic spellings and thus the most difficult to learn. English is, in its origin, a Germanic language. From its early roots as Anglo-Saxon, it has borrowed words from many other languages: French (a Romance language) and Latin are the most frequent donors to English. Languages that use phonetic spelling are easier to learn to spell than others. With phonetic spelling the words are spelled as they are pronounced. The Italian word "orologio" for instance is pronounced oh-ro-LO-jo ("gi" always making a "j" sound.) In English, one comes across the word "knife". In "knife", the "k" is not spoken, even though in English it's more common to pronounce "K"s when they are in words. History of English spelling One of the problems we have is that similar sounding words may be spelt quite differently. Rough and ruff; meet and meat; great and grate. Words with complicated spelling may be pronounced simply: Leicester is pronounced 'Lester'. Even what rules we do have are frequently broken. "i before e except after c" has over 100 exceptions.p272 Almost all these problems have come about for historical reasons. English has been changing for the last thousand years, and as the language changes, so parts of it get stuck with different spellings. Here are some of the causes of English orthography: Originally a 23-letter alphabet for the 35 or so phonemes (sounds) of Old English. Other letters were added later. After the Norman conquest, French scribes introduced new spellings. Printing. Many of the early printers came from the continent of Europe, and brought other spelling norms to England. But, although print stabilised spelling, pronunciation continued to change. Printing coincided with the Great Vowel Shift at the end of Middle English (end 14th to 15th centuries). To avoid complex details, here is what happened: over a century, the pronunciation of all the vowels changed, and is still not standard throughout Britain. In any event, the spelling of thousands of words now reflects their pronunciation in Geoffrey Chaucer's time. 16th-century scholars tried to indicate the history of a word by its spelling: the silent 'b' in 'debt' is there to reflect the Latin debitum. More loan words added in the late 16th to early 17th century, such as pneumonia, idiosyncrasy, epitome, cocoa. English has a huge number of words, but its spelling comes from many different sources. "The large and varied lexicon of English has been bought at the expense of an increasingly deversified graphology".p275 Differences between languages Some languages have a high correspondence between phonemes and letters. That means they get close to one letter for each sound. If there was a perfect correspondence, that language would have phonemic orthography. English is highly non-phonemic. It has almost every kind of deviation known: different letters for the same sound two or more letters for a single sound sound depends on nearby letters vast range of words whose sound varies according to dialect huge number of loan words with imported spellings defective: it does not represent some important differences in phonemes. Example: the difference between the voiced th (the) and the unvoiced th (thin). This field of study is called "orthographic depth". The orthographic depth of an alphabetic script is the degree to which a written language deviates from simple one-to-one letter–phoneme correspondence. It shows how easy it is to predict the pronunciation of a word from its spelling. Shallow orthographies are easy to pronounce based on the written word, and deep orthographies are difficult to pronounce based on how they are written. In shallow orthographies, the spelling-sound correspondence is direct: given the rules of pronunciation, one is able to "say" the word correctly. Most other international languages have similar problems: in French, Arabic or Hebrew, new readers have difficulty learning to decode words. As a result, children learn to read more slowly. In both Spanish and Italian there is a more direct connection between spelling and pronunciation. Those are languages with low orthographic depth. Related pages Ghoti References Language

The word oil is used for many different kinds of liquids. Oil usually does not mix with water. Vegetable oils are made from plants. Many are used in foods and for cooking. Some kinds of plant oils that people use are palm oil, maize (corn), olive, peanut, soy, and sunflower. Other kinds of oil are made from crude oil (petroleum) which comes from under the ground. People use large oil wells to bring the oil up to the surface. The oil is sent in special ships called tankers or in pipelines to factories called refineries where it is distilled into LPG, gasoline (petrol), diesel fuel, and fuel oil. Plastics are among the Petrochemicals made from crude oil or natural gas. Oils from crude oil are also used as fuels for engines or as lubricants to make the parts of machines work together without sticking or stopping. Different kinds of oils are also used for many other things, for example to make cosmetics, medicines, paints, and detergents, like washing up liquids. Soap(s) are similar to detergents, but they are generally made from animal fat(s) rather than oils. Oil is also made for various purposes including synthetic fuel and lubricant. Basic English 850 words Hydrocarbons

OK (okay) is a word in the English language. It is used to mean that something is good or correct. It is the opposite of the word bad. It can often be used instead of the word Yes. It is not certain where the word "OK" originally comes from, but some experts say it came from a funny way of writing "Ol Korrect" (All correct). It is also the two-letter abbreviation for the state of Oklahoma in the United States of America. You also find the phrase "Ola kala" in Greek, which means 'All Correct". For Example: I think it is 'ok' to present this project in our office. Background The term appears to have achieved prominence in the United States in 1840, when supporters of the American Democratic political party claimed during the 1840 United States presidential election that it stood for "Old Kinderhook," a nickname for a Democratic presidential candidate, Martin Van Buren, a native of Kinderhook, New York. "'Vote for OK' was snappier than using his Dutch name." In response, Whig opponents attributed OK, in the sense of "Oll Korrect," to Andrew Jackson's bad spelling. The country-wide publicity surrounding the election appears to have been a critical event in okay's history, widely and suddenly popularizing it across the United States. Notes Words

An oxymoron is a term for a figure of speech. It is made up of two or more words that seem to be opposite to each other, or actually are opposite. For example, the phrases "Wise fool", "Warm freezer", and "Legal murder" all have two words. In each one, the one word looks like the opposite of the other word. You can have words that look opposite, but are right. For example, a "warm freezer" could be right. A freezer could be warm if it was turned off or left open. The word oxymoron is an oxymoron; 'oxy' comes from the Greek word that means 'sharp', while 'moron' comes from the Greek word that means 'dull'. Words that really are opposite to each other, would be words that just cannot be put together. For example, a "round square" could not happen because squares are not round. Oxymorons sometimes appear in jokes. Sometimes, the joke is just to say that a pair of words are an oxymoron. For example, a joke that says that "glutted peasant" is an oxymoron. This means that peasants are usually hungry, if the word 'peasant' is opposite to 'glutted' Related pages Paradox Trope References Logic Figures of speech

An operating system (or OS) is a group of computer programs, including device drivers, kernels, and other software that lets people interact with a computer. It manages computer hardware and software resources. It provides common services for computer programs. An OS can be small (like MenuetOS), or large (like Microsoft Windows). Different operating systems can be used for different purposes. Some are used for everyday things like on a personal computer. Others are mobile operating systems or are used for specialized work. An operating system has many jobs. It makes sure that all the programs can use the CPU, system memory, displays, input devices, and other hardware. Some also give the user an interface to use a computer. An OS is also responsible for sending data to other computers or devices on a network. Some examples of commonly used operating systems are macOS, Linux, and Microsoft Windows. History The first operating system was used with the ENIAC (Electronic Numerical Integrator and Computer). It was very hard to make ENIAC do work. How the operating system worked was based on how the switches and cables were put together and depending on this factor punch cards would make a result. While this was an operating system of a kind, it is not what is thought of as one in modern times. The first operating system that looked and felt like operating systems in the modern age was UNIX, made in 1969 by Bell Labs. It had a small kernel and many tiny programs that could be put together to work with user input and data. Many of its features were taken from Multics, an older operating system made in 1964. Types Single- and multi-tasking A single-tasking system can only run one program at a time. A multitasking operating system can run more than one program at the same time. Multi-tasking is done by dividing processor time. The processor gives a little bit of its time to each program. Single- and multi-user Single-user operating systems cannot distinguish between users, but may allow multiple programs to run simultaneously. A multi-user operating system permits multiple users to interact with the system at the same time. Distributed A distributed operating system manages a group of distinct computers and makes them appear to be a single computer. Distributed computations are carried out on more than one machine. Templated In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine as a guest operating system, then saving it as a tool for multiple running virtual machines. The technique is common in large server warehouses. Embedded Embedded operating systems are designed to be used in embedded systems. They are designed to operate on small machines like PDAs with less autonomy and are able to operate with a limited number of resources. Real-time A real-time operating system guarantees processing of events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts. Library A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Related pages BIOS References

Philosophy is the study of underlying things. This means philosophy tries to understand the reasons or basis for things. It also tries to understand how things should be. "" is the Ancient Greek word for the "love of wisdom". A person who does philosophy is called a philosopher. A philosopher is a kind of thinker or researcher. A "philosophy" can also mean a group of ideas by philosophers, or by a philosopher. Philosophy is a way of thinking about the world, the universe, and society. In the past, sciences were part of philosophy as well. Ideas The ideas in philosophy are often general and abstract. But this does not mean that philosophy is not about the real world. Ethics, for example, asks about how to be good in our day-to-day lives. Metaphysics asks about how the world works and what it is made of. Sometimes people talk about how they have a ‘personal philosophy’, which means the way a person thinks about the world. This article is not about people's ’personal philosophies’. This article is about the ideas that have been discussed by philosophers (people who think and write about ways of thinking) for a long time. Questions One philosophical question is this: "Is there any knowledge in the world which is so certain that no reasonable man could doubt it?". Other questions asked by philosophers are these: what should we do in our lives? What happens to a soul after death, how does a soul enter into the body before death? Why are we born? Why should we live? Why are there so many hurdles in life? How do we overcome suffering? What is the importance of the material life? Will the universe exist forever? What is beauty? Do we have free will? Does God exist? Does the world around us exist? What is truth? What is evil? What is the relationship between mind and body? What is the meaning of life? History The etymological meaning of the word 'Philosophy' is 'love of wisdom'. It comes from the Greek word 'Philosophia', with 'Philo' meaning 'beloved' and 'Sophia' meaning 'wisdom. There are different types of philosophy from different times and places. Some philosophers came from Ancient Greece, such as Plato and Aristotle. Others came from Asia, such as Confucius or Buddha, or Adi Shankara and Laozi. Some philosophers are from the Middle Ages in Europe, such as William of Ockham or Saint Thomas Aquinas. Philosophers from the 1600s, 1700s, and 1800s included Thomas Hobbes, René Descartes, John Locke, David Hume, and Immanuel Kant. Philosophers from the 1900s included Søren Kierkegaard, Ludwig Wittgenstein, and Jean-Paul Sartre. Areas of inquiry Philosophy is the study of humans and the world by thinking and asking questions. It is a science and an art. Philosophy tries to answer important questions by coming up with answers about real things and asking "why?" Sometimes, philosophy tries to answer the same questions as religion and science. Philosophers do not all give the same answers to a question. Many types of philosophy criticize or even attack the beliefs of science and religion. In his work Critique of Pure Reason, Immanuel Kant asked the following questions: What can I say? What shall I do? What dare I hope? What is man? The answers to these questions gives the different domains or categories of philosophy. Categories in philosophy Philosophy can be divided into different groups, based on the types of questions that it asks. Below is a list of questions split into groups. One possible list of answers to these questions can be called a 'philosophy'. There are many different 'philosophies', because all of these questions have many different answers according to different people. Not all philosophies ask the same questions. These are the questions that are usually asked by philosophers from the Western world:Metaphysics: Metaphysics is sometimes split up into ontology (the philosophy of real life and living things), the philosophy of mind and the philosophy of religion; but these sub-branches are very close together. Ontology: What is the world that we see around us? (What is reality?) Is there more to the world than just what we see or hear? If nobody sees something happening, does that mean that it did not happen? What does it mean to say that something is possible? Do other worlds exist? Is there anything very special about being a human being or being alive at all? If not, why do some people think that there is? What is space? What is time? The philosophy of mind: What is a mind? What is a body? What is consciousness? Do people make choices, or can they only choose to do one thing? (Do people have free will?) What makes words or ideas meaningful? (What is the relation between meaningful words or ideas and the things that they mean?) The philosophy of religion: Do people have souls? Is there a God who created the Universe?In epistemology: What is knowledge? How can we know anything? What is science? What is truth?In ethics: What are right and wrong, good and bad? Should people do some things and not others? What is justice?In aesthetics: What is beauty? What if one person thinks a painting is beautiful, but another person thinks the painting is ugly? Can the painting be beautiful and ugly at the same time? Are true things beautiful? Are good things beautiful? What is art? We commonly think that a sculpture in a museum is art. If a sculptor sculpts a sculpture of a rock from clay, and puts it in a museum, many would call it art. But what if a person picks up a rock from the ground - is the rock a piece of art?In logic: What do the words we use mean? How can we say things (especially ideas) in a way that only has one meaning? Can all ideas be expressed using language? How does the truth of an argument's premise affect the truth of its conclusion? How can we reason correctly?In axiology''': What has value? Is time really money? or have we made it so? Does love, beauty, or justice hold any value? Other divisions include eschatology, teleology and theology. In past centuries natural science was included in philosophy, and called "natural philosophy". Is philosophy good or bad? Does philosophy do any good? Very few people would dispute this. It is easy to argue that philosophy is a good thing, because it helps people to think more clearly. Philosophy helps people to understand the world and the way people act and think. Philosophers believe that asking philosophical questions is useful because it brings wisdom and helps people to learn about the world and each other. Some philosophers might even argue that the question "Is philosophy good or bad?" is a philosophical question itself. However, some people think that philosophy is harmful, as philosophy encourages free-thinking and often questions the beliefs that others hold. For example, philosophies such as some existentialist views say that there is no meaning to life or human existence, except the meaning that we make up or invent. People from some religions do not agree with the beliefs of existentialism. Every major science, including physics, biology, and chemistry, are disciplines that were once considered as philosophy. Medicine was always considered a practical art, however. As facts about nature became more understood, these subjects branched away. Psychology only split a century and a half ago. In our own time, subjects such as consciousness studies, decision theory, and applied ethics have increasingly found independence from philosophy as a whole. Because of this, philosophy seems useful because it spins off new kinds of science. What philosophers do Philosophers ask questions about ideas (concepts). They try to find answers to those questions. Some thinkers find it very hard to find those words that best describe the ideas they have. When they find answers to some of these questions philosophers often have the same problem, that is how to best tell the answers they found to other people. Depending on the meaning of the words they use, the answers change. Some philosophers are full-time thinkers (called academics), who work for universities or colleges. These philosophers write books and articles about philosophy and teach classes about philosophy to university or college students. Other philosophers are just "hobby" thinkers who think about philosophy during their free time. A small number of hobby thinkers have thought so much about philosophy that they are able to write articles for philosophy magazines. Other people approach philosophy from another job. For example, monks, artists, and scientists may think about philosophical ideas and questions. Most philosophers work by asking questions and looking for good definitions (meanings) of words to help them understand what a question means. Some philosophers say the only thing needed to answer a question is to find out what it means. The only thing that makes philosophical questions (such as those above) difficult is that people do not really know what they mean. Ludwig Wittgenstein believed this. Philosophers often use both real and imaginary examples to make a point. For example, they may write about a real or fictional person in order to show what they think a good person or a bad person is like. Some philosophers look for the simplest way to answer a question and say that is probably the right answer. This is a process called Occam's razor. Others believe that complicated answers to questions can also be right. For an example of a philosophical problem, see the God paradox. Philosophers use logic to solve problems and answer questions. Logical consistency is a cornerstone of any acceptable theory. Philosophers who disagree with a theory will often try to find a logical contradiction in a theory. If they find a contradiction, this gives them a reason to reject that theory. If they do not find an inconsistency, the philosopher might show that the theory leads to a conclusion which is either unacceptable or ridiculous. This second approach is usually called reductio ad absurdum. Some philosophers People listed here should be genuine philosophers, rather than social or political campaigners. The lists are not meant to be complete. The ancient Greek philosophers Heraclitus Socrates Plato Aristotle Epicurus Diogenes Later European/Western philosophers Saint Augustine Saint Thomas Aquinas Duns Scotus Bonaventure William of Ockham George Berkeley Auguste Comte René Descartes Ralph Waldo Emerson Georg Wilhelm Frederich Hegel Thomas Hobbes David Hume Immanuel Kant Søren Kierkegaard Gottfried Wilhelm Leibniz John Locke Niccolò Machiavelli John Stuart Mill Jean-Jacques Rousseau Arthur Schopenhauer Baruch Spinoza William Whewell Friedrich Nietzsche Modern European and American philosophers Louis Althusser G. E. M. Anscombe Simone de Beauvoir David Chalmers John Dewey Christian DeQuincey Martin Heidegger Karl Popper John Rawls Bertrand Russell Jean-Paul Sartre Ludwig Wittgenstein Albert Camus Latin American and Latina/o philosophers Gloria E. Anzaldúa Giannina Braschi Sor Juana Inez de la Cruz Maria Lugones Ofelia Schutte Eugenio María de Hostos Asian/Eastern philosophers Avicenna Osho Confucius Siddhārta Gautama (the Gautama Buddha) Omar Khayyám Nanak Chuang Tzu Lao Tzu Sohrevardi Allama Iqbal Related pages Fallacy Truth General sources Blumenau, Ralph. Philosophy and living. Craig, Edward. Philosophy: a very short introduction. Harrison-Barbet, Anthony. Mastering philosophy. Russell, Bertrand. The problems of philosophy. Sinclair, Alistair J. 2008. What is philosophy? An introduction. Sober, Elliott 2001. Core questions in philosophy: a text with readings. Upper Saddle River, Prentice Hall. Solomon, Robert C. Big questions: a short introduction to philosophy. Warburton, Nigel. Philosophy: the basics. Nagel, Thomas. What does it all mean? A very short introduction to philosophy. Pojman, Louis P. Classics of Philosophy (vols. 1, 2, & 3) Arthur, Edwin The English Philosophers from Bacon to Mill Beardsley, Monroe European Philosophers from Descartes to Nietzsche Cottingham, John 2008. Western philosophy: an anthology. 2nd ed. Malden, MA: Blackwell Pub., . Tarnas, Richard. The passion of the Western mind: understanding the ideas that have shaped our world view''. References Other websites The School of Life on YouTube Einzelgänger (In search of) on YouTube Philosophy Humanities

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

Politics is the way that people living in groups make decisions. Politics is about making agreements between people so that they can live together in groups such as tribes, cities, or countries. In large groups, such as countries, some people may spend a lot of their time making such agreements. These people are called politicians. Politicians, and sometimes other people, may get together to form a government. The study of politics in universities is called political science, political studies, or public administration. In everyday life, the term "politics" refers to the way that countries are governed, and to the ways that governments make rules and laws. Politics can also be seen in other groups, such as in companies, clubs, schools, and churches. Government The government tries to lead the whole group. Governments do things such as: Decide which people get which pieces of land Decide which people can tell other people what to do Decide whether to go to war with another country Create money Build things for the use of the whole group, such as roads, hospitals, libraries, and docks. Educate people, either for their own good, or to teach them what the government wants them to know Take care of the very young, the sick, or the very old Manage the welfare of the country and manages the money available for spending on services (Hospitals, Schools, etc.) One of the ways the government leads the group is by making laws and rules which tell everybody what they can and can not do. The government makes these laws so that society will be safe and well-ordered. The law that says "you must not drink alcohol while driving a car" stops people from drunk driving, which could kill people. The law that says "you must wear a helmet on a motorcycle" makes sure that people protect themselves when riding their motorcycles. The government can also control people and what happens in a country in other ways besides making laws. For example, how the government spends its money makes a big difference in what people will do or what will happen to people. If the government spends a lot of money on hospitals and nurses, the people will probably become healthier. Also, if people like their government, or think that their government is wise, they may do something just because their government says it is a good thing to do. Governments often make posters or television advertisements that encourage people to stop smoking cigarettes or eat more fruits and vegetables. Politics is often compared to ethics (ideas about right and wrong). Ethics is a more abstract study of right and wrong. Ethics is usually more concerned with principle than law or politics or diplomacy, so many people think ethics is not practical. But without some agreement on ethics, there is probably no way to even have a debate, laws or an election. There is always some agreement on ethics and personal conduct in a political system. Political parties In most countries, people have formed political parties to put forward their ideas. There is usually some disagreement between people within a party, but they work together because they feel that they agree on enough things, and they will have more power if they join together. They agree to take the same position on many issues, and agree to support the same changes to law and the same leaders. An election is usually a competition between different parties. Some examples of parties are the Liberal party, the Labor party and the Greens. History The Greek philosopher Aristotle wrote that humans are a political animal and that ethics and politics are closely linked. Niccolò Machiavelli wrote, in his 1532 book, The Prince, that politics was firstly about having and keeping power. He said that without power, a leader could do nothing. In 1651, Thomas Hobbes wrote Leviathan, a book about politics. Hobbes wrote that people living in groups often give up some of their rights in exchange for some protections from a government. In the 1800s, John Stuart Mill developed the "liberal" idea of politics. Mill said that democracy is the most important political development of the 1800s. He said that there should be more protection for individual rights against the government. Bernard Crick wrote a list of the political virtues, which were about best practices of politics itself. International politics There are also disagreements between different countries. Attempts to solve the problem with meetings are called diplomacy. This is politics between nations instead of politics within nations. If the problems are not resolved by diplomatic meetings they can lead to war or terrorism. Related pages Identity politics Political economy Political philosophy Constitution Geopolitics Other websites Politics -Citizendium

A value (or principle) usually means an abstract rule, one that can be seen to apply in many experiences, or can be applied by choice in a lot of situations. It can also mean a moral choice one makes often and consistently, for example, some Buddhists avoid eating meat as a matter of principle. Many groups of people agree on lists of principles. They may also try to agree on the order in which they are to apply, that is, which principles should be violated before which other ones. They might also try to list best practices which reflect the principles in the right order, and provide more practical (less abstract) instruction. Culture

Profanity means bad/swear words, and/or using vulgar/offensive language. The adjective is profane. Profanities can also be called curse ("cuss") words, dirty words, bad words, foul language, obscenity, obscene language, or expletives. It can be called swearing, although this also has a normal meaning of making a "solemn promise". A profanity usually refers to religion, sex, or bodily functions. These are things that people feel very strongly about. In some languages, such as French, there is more profanity about religion than most other topics. This is the original meaning, from a Latin word meaning "before the temple". Religious profanity is called blasphemy. The verb is to blaspheme and the adjective is 'blasphemous'. Saying “God!” or “Jesus Christ!” as an expression of surprise or annoyance is considered by many to be blasphemy, mostly because one of the Ten Commandments says not to use God's name "in vain" (without substance or without relevance). Swearing oaths can also be considered wrong by some who follow Jesus' teaching against swearing oaths in the Gospels (such as Matthew 5:34). A profanity can be a word or gesture or some other form of behavior. Different words can be profane to different people, and what words are thought of as profanity in English can change over time. Whether a word is a profanity will always depend on the way people think. Some people will be offended by something, while others will not be. Words which should not be used are taboo words. Using such words is thought by some people to be a sin. For example, some Christians and some Muslims believe that swearing is a sin. Opinions on profanity Some people call profanity "crude," but some say that it is no cruder to say "damn" or "crap" than it is to use "hate" (a word that is about a very strong emotion, but not a swear word). People who use profanity do not always mean to make anybody feel bad, and tolerance for different forms of profanity can vary widely, from person to person. Most often, using profanity is a verbal outlet for strong feelings (usually unpleasant ones), that might otherwise cause a physical reaction. At other times, some people may use profanity as humor. Coprolalia Coprolalia is a mental condition that makes people use profanity constantly. It is different from Tourette syndrome. Tourette syndrome is actually a group of symptoms that only includes coprolalia 15% of the time. The condition can be made worse by stress. Examples of profanity Several of these words come from Anglo-Saxon or old Norse names for body parts, and bodily functions. They came to be thought of as profanity mostly after the Normans brought French and Latin words for them to England. Ass (or Arse) Means the buttocks. Asshole (or Arsehole) Means the anus. Also used as an insult for a mean and unpleasant person. Bastard A term for a child who was born to unmarried parents. Also used as an insult for an unpleasant person. Bitch A female dog. Also used as an insult for a disliked woman. Cock (or Dick) These terms refer to the penis, and/or as an insult for a unpleasant person or a fool. Cunt (or Pussy) A vagina. Also used as an insult for a disliked person. Fuck A verb, meaning to have sex. Piss Urine; also a verb, meaning to urinate. Shit (or Shite) Feces; also a verb, meaning to defecate. Profane gestures These are mostly performed while facing another person and can be meant toward them, or about them. These gestures are considered as strong as profane words in most cases. Biting one's thumb Performed by placing the tip of a thumb under the front teeth, then pulling the thumb slightly forward, with the fingers closed. Mocks the "thumbs up" gesture. Can be taken to mean "bite me", though it predates the common use of this phrase. Grabbing one's own crotch Also an invitation to "bite me", or to perform oral sex in a way. Pretending to give fellatio One pokes out a cheek with the tongue while rocking a closed hand toward the mouth, at the same time. Indicates something or someone is a waste of time. Pretending to masturbate Indicates something or someone is a waste of time, or performs poorly. Showing one's middle finger ("flipping the bird") Understood generally to mean "fuck you" or "fuck off". Showing a reversed "V" sign Understood generally to mean "fuck you" or "fuck off". Thumbing (or "fluting") one's nose Performed by placing the tip of a thumb against the tip of the nose, then wiggling the fingers. Expresses , or thinking that someone is foolish. "Up yours" One turns a forearm horizontally while swinging the other fist and forearm around it. Suggests something being shoved into a person's . If the middle finger is shown, it is a stronger form of "fuck you", or a suggestion of anal sex. References Human communication Obscenity

Proof could mean: An argument, including: Mathematical proof Proof theory, a branch of mathematical logic Logical argument Evidence (law), tested evidence or a legal proof Proof (alcohol), measure of an alcoholic beverage's strength Proofing (baking technique), how a yeast-leavened dough rises Proofreading Artist's proof, a single print taken during the printmaking process Proof coinage, a coin made as an example of a particular strike Proof test, for a firearm Galley proof, an early version of a publication Homeopathic proving, testing a substance's effect on the body In entertainment: Proof (1991 movie), an Australian movie by Jocelyn Moorhouse Proof (play), a play by David Auburn Proof (2005 movie), a movie directed by John Madden, based on the play "Proof", a song by Paul Simon from his 1990 album The Rhythm of the Saints Proof (rapper) (1973-2006), American rapper, a member of the group D12

The People's Republic of China (PRC) () is a one-party state in East Asia governed by the Chinese Communist Party (CCP). It was founded on 1 October 1949. It currently has more than 1.4 billion people (as of 2017), which is more than any other country in the world. It covers an area of 9.6 million square kilometers. The capital city is Beijing and Shanghai is the city with the most people living in it. Along with the cities of Tianjin and Chongqing, these four cities are "municipalities" directly controlled by the national government. Two other cities are given the status of "special administrative region" (SAR). They are Hong Kong, which was once a colony of the United Kingdom and given back to China in 1997 and Macau, which Portugal gave back in 1999. These two cities remain highly autonomous or have much of their own power. Aside from the "municipalities" and the "SARs", there are 23 provinces and five "autonomous regions" or regions with more law-making rights than the provinces and with many people of a minority group population. They are the Xinjiang Uyghur Autonomous Region, the Tibet Autonomous Region or Xizang Autonomous Region, the Guangxi Zhuang Autonomous Region, the Inner Mongolia Autonomous Region or Nei Mongol Autonomous Region and the Ningxia Hui Autonomous Region. In the SARs, the central government is responsible for defense and foreign affairs but not the daily operations for 50 years. PRC claims Taiwan as one of its many provinces. However, PRC does not have control of Taiwan which has an entirely different political system and officially known as the Republic of China (Taiwan). History China has one of the world's oldest civilizations and has the oldest continuous civilization. It has archaeological evidence over 5,000 years old. It also has one of the world's oldest writing systems (and the oldest in use today), and is viewed as the source of many major inventions. Ancient (2100 B.C. - 1500 A.D.) Ancient China was one of the first civilizations and was active since the 2nd millennium BC as a feudal society. Chinese civilization was also one of the few to invent writing, with the others being Mesopotamia, the Indus Valley civilization, the Maya civilization, the Minoan civilization of ancient Greece, and Ancient Egypt. It reached its golden age during the Tang Dynasty (c. A.D. 10th century). Home of Confucianism and Daoism, it had great influence on nearby countries including Japan, Korea, and Vietnam in the areas of political system, philosophy, religion, art, and even writing and literature. China is home to some of the oldest artwork in the world. Statues and pottery, as well as decorations made of jade, are some classic examples. Before the Qin Dynasty united China, there were hundreds of small states that fought each other for hundreds of years in a war to control China. This is known as the Warring States Period. Although the continuing wars made people suffer, it was at this time when many of the great philosophies of the East were born, including Confucianism and Daoism. Confucianism and Daoism alone have been the foundation of many social values seen in modern eastern-Asian cultures today. Its geography mostly looked like that of modern China, except with northern and western edges that varied. It was often attacked by northern nomadic people such as the Turkic tribes and the Mongols lead by Genghis Khan and Kublai Khan. During the history of ancient China, the northern nomadic people and the Chinese people had been fighting each other and taking turns to rule the land and the people of China. However, when the northern people beat the Chinese people and came to rule the kingdom, they also Incorporated the Chinese way of living and became like the Chinese. Many of the strongest dynasties of China were ruled by the northern people, including the Qin, Tang, Yuan (Mongolian), and Qing (Manchu). Each time, they also brought new elements into the Chinese culture. A new age While China achieved many things in the First millennium and early 2nd millennium, it became an isolationist country in the 15th century C.E. This was because Spain found a lot of silver in the newly explored continents of North and South America. Silver was the main currency (money) in China and Europe at the time, and China did not want to be bought by the foreigners. By the time of the Renaissance, European powers started to take over other countries in Asia. During this time the opium epidemic was growing in China. Foreign traders (primarily British) had been illegally exporting opium mainly from India to China since the 18th century, but that trade grew dramatically from about 1820. The resulting widespread addiction in China was causing serious social and economic disruption there. This led to what is now known as the first opium war. The first Opium War between China and Great Britain lasted from 1839 to 1842. The conflict was the result of years of attempts by the British to exploit China as a market for British goods. Britain eventually relied on its superior military capabilities to force open the lucrative Chinese market, while imposing an illicit trade in opium on the Chinese people. While China was never actually taken over by Europeans, many European countries, such as Britain and France built spheres of influence in China. Since China had cut itself off from the world over the previous few centuries, by the Qing Dynasty, it had fallen behind other countries in technology, and was helpless to stop this from happening. This had become clear when it lost the Opium Wars to Britain in the 19th century. In 1912, the Qing dynasty was overthrown by the Sun Yat-sen and the Kuomintang, a nationalist party, and the Republic of China established. Over time, Marxist ideas grew popular and the Communist party was formed. The Chinese Civil War later started between the Kuomintang (Nationalists) of the Republic of China (ROC) and the Communists of the People's Republic of China (PRC). The Communists wanted to make China like the Soviet Union, whereas the other side wanted to keep China in its current state at the time. The Communists were led by Mao Zedong, Zhou Enlai, Liu Shaoqi and others. Later Liu lost influence with Mao and his death to this day remains unresolved. The Communists eventually won the war. The Nationalists (led by Chiang Kai-shek) fled to the island of Taiwan and set up their new capital city in Taipei. After the Chinese Civil War, the Communist leader Mao Zedong declared a new country, the People's Republic of China (PRC), in Beijing on October 1, 1949. In 1927, the Chinese Civil War began as the Kuomintang, led by Chiang Kai-shek, and the Communists fought one another. Amidst the turmoil brewing between the Nationalist and Communist parties who were vying for control of China at the time, Japan had launched an invasion of Manchuria in 1934 and began to creep steadily inland. China, the Nationalist party in particular, owed Japan immense amounts of money, which they could not pay whilst infused in their own civil war. The Treaty of Versailles promised the Japanese government land in China in return for forgiveness of their debt. This ended up not being a popular sentiment and was rallied against all over the country, and most famously during the May 4th Movement in Beijing in 1919. When the Chinese did not readily give up their rights to their land, Japan tried to take it by force. This was the beginning of World War II in the Pacific Theater. By 1949, the Red Army of the Chinese Communist Party had gained control over mainland China and Mao Zedong announced the creation of the People's Republic of China. Chiang Kai-shek and the other nationalists fled to Taiwan. As the Chairman of the Chinese Communist Party, Mao began many social and economic reform projects with mixed results. The Great Leap Forward, from 1958 to 1961, tried to industrialize China and increase its food production, but resulted in one of the largest famines in history. It is estimated that 45 million people died as a result of this reform project. In 1966, Mao began the Cultural Revolution to remove capitalist influences from society and government. Major government officials and ordinary citizens were accused of being "revisionists" - people who disagreed with some parts of Marxism - or "counter-revolutionaries" and were persecuted. Many universities and schools were closed, and historical and religious sites were destroyed. Although the program officially ended in 1969, it continued until Mao's death in 1976. During this time period, the People's Republic of China did not get along with the capitalist countries of the Western world. Beginning in the 1960s, relationships between the People's Republic of China and the Soviet Union also became increasingly unfriendly in the Sino-Soviet Split. In 1972, to counter the power of the Soviet Union, Chairman Mao and Chinese Premier Zhou Enlai met with US President Richard Nixon in Beijing. This began to improve relationships between China and the Western world. After Mao's death, there was a power struggle between the Gang of Four and Chinese Premier Hua Guofeng, the man Mao had chosen to be the next leader of China. Eventually, Deng Xiaoping, one of the veterans of the revolution, took power. He began a "Reform and Opening Up" () campaign. These reforms tried to make the People's Republic of China a modern, industrial - but still socialist - nation by moving towards a market system. Deng's policies would be known as "socialism with Chinese characteristics." Although Deng's policy helped loosen restrictions on citizens, the People's Republic of China continues to have problems with the amount of control the government has over citizens' private lives. In 1979, the one-child policy, which limits most couples to one child, was created because of the overpopulation problem in the People's Republic of China. This policy is highly controversial and many Westerners have criticized it. News and Internet sites are also censored by the government. In 1989, the Chinese Communist Party used soldiers and tanks to stop a protest in Beijing's Tiananmen Square organized by students seeking political reform. This action received worldwide criticism and led to economic sanctions being placed on the Chinese government. In August 2008, China hosted the Summer Olympics for the first time. Geography The People's Republic of China is the third- or fourth-largest country in the world after Russia, Canada, and (in some sources) the United States and the second-largest by land area. China has every kind of climate in the northern hemisphere except the polar climate. It is also the largest country without any land north of the Arctic Circle. China borders 14 nations, which is more than any other country in the world. It borders Vietnam, Laos, and Burma in Southeast Asia; India, Bhutan, Nepal and Pakistan in South Asia; Afghanistan, Tajikistan, Kyrgyzstan and Kazakhstan in Central Asia; a small section of Russian Altai and Mongolia in Inner Asia; and the Russian Far East and North Korea in Northeast Asia. China has two major rivers, the Yellow River and the Yangtze River. There is also the Taklamakan and the Gobi Desert. The world's highest point, Mt. Everest (8848m), is on the border between China and Nepal. The country's lowest point, and the world's fourth-lowest, is the dried lake bed of Ayding Lake (−154m). Biodiversity China is one of 17 megadiverse countries. It is in two of the world's major ecozones: the Palearctic and the Indomalaya. In the Palearctic zone, mammals such as the horse, camel, tapir, and jerboa can be found. Among the species in the Indomalaya region are the Leopard Cat, bamboo rat, treeshrew, and various monkey and ape species. Some overlap is between the two regions; deer, antelope, bears, wolves, pigs, and many rodent species can all be found in China's environments. The famous giant panda is found only in a limited area along the Yangtze River. China has a continuing problem with trade in endangered species. There are now laws to stop such activities. China also has a variety of forest types. Cold coniferous forests cover most of the north of the country. The forest have animal species such as moose and the Asian black bear, along with over 120 bird species. Moist conifer forests can have thickets of bamboo. It is replaced by rhododendrons in higher montane stands of juniper and yew. Subtropical forests, which are mostly in central and southern China. These support as many as 146,000 species of flora. Tropical and seasonal rainforests, though confined to Yunnan and Hainan Island, have a quarter of all the plant and animal species found in China. Politics China is a one-party state wherein the General Secretary of the Chinese Communist Party (CCP) holds ultimate power and authority over state and government and serves as the paramount leader. The current General Secretary is Xi Jinping, who took office on 15 November 2012 and was re-elected on 25 October 2017. The President is the titular head of state, elected by the National People's Congress. The current president is Xi Jinping, who is also the General Secretary of the Communist Party of China and the Chairman of the Central Military Commission, making him China's Paramount leader. The Premier is the head of government, heading the State Council alongside with four vice premiers and the heads of ministries and commissions. The current premier is Li Keqiang, who is also a senior member of the CCP Politburo Standing Committee, China's de facto top decision-making body. Military The PRC Armed Forces, also known as the People's Liberation Army (PLA), is one of the most powerful armies in the world. Nowadays PRC is among the atomic powers in the world. It also has the largest standing army in the world of over 2 million soldiers on active duty. People and culture There are 56 recognized ethnic minority groups in China. Han is the largest ethnic group in China. Mandarin Chinese is the main spoken language. China is the origin of Eastern martial arts, called Kung Fu or Wushu. China is also the home of the well-respected Spa Monastery and Wudang Mountains. Martial art started more for the purpose of survival, defense, and warfare than art. Over time some art forms have branched off, while others have retained their distinct Chinese characteristics. China has had renowned artists including Wong Fei Hung and many others. Art has also co-existed with a variety of paints including the more standard 18 colors. Legendary and controversial moves like Big Mak are also praised and talked about within the culture. China has many traditional festivals, such as the Chinese New Year, Dragon Boat Festival, Mid-Autumn Festival and so on. The most significant is Chinese New Year. Another important holiday is the National Day celebration around October. Weekends are moved around to make sure everyone has a week-long holiday for it, just like during the lunar new year. Festivals Chinese New Year lasts fifteen days, including one week as a national holiday. It starts with the first day of the Chinese lunar year and ends with the full moon fifteen days later. It is always in the middle of winter, but is called the Spring Festival in Chinese because Chinese seasons are a little different from English ones. On the first day of the Chinese New Year, people call on friends and relatives. Because most people watch the special performances on CCTV all the night on New Year's Eve and don't go to bed until 12:00 AM, they usually get up later in the next day. The fifth day of the Chinese New Year is the day to welcome the god of Wealth (Chinese:财神爷), many people make and eat dumplings (Chinese:饺子. Pinyin: Jaozi). They believe that dumplings can hold the god of Wealth and bring luck. The last day of the Chinese New Year is the Lantern Festival. On this day, the moon becomes the full moon. People go out and watch the lantern festivals everywhere. After that, they eat sweet dumpling (Chinese:汤圆,元宵), a kind of dumpling which is round and looks like the full moon. Dragon Boat Festival is celebrated to commemorate the death of Qu Yuan, a patriotic poet of the State of Chu during the Warring States period. He persuaded his emperor not to accept Qin's diplomats's offers several times but his emperor did not listen to him. He was very sad and ended up jumping into the river to end his life. The people loved him so much that they did not want the fish to eat his corpse. They made and threw rice dumplings into the river. They hope the fish eat these dumplings instead of the poet's corpse. They also rowed dragon boats in the river to get rid of the fish. Eating rice dumplings and holding dragon boat races, became what the Chinese do in this festival nowadays. Held on the fifteenth day of the eighth lunar month, the Mid-Autumn Festival is a festival for families. Now when the festival sets in, people sit together to eat moon cakes, appreciate the moon and the moon itself, celebrate the bumper harvest, and enjoy the family love and happiness. To the Chinese people, the full moon symbolizes family reunion, as do the moon cakes. Hence why the Mid-Autumn Festival is also called the Family Reunion Festival. Transport Trains are commonly used for moving from one place to another, mainly for long distances. Bullet trains are faster and more common in the cities. China has more high-speed trains than any other country in the world. Buses and air transport are also very common. Related pages List of provinces of China Political problems of China Notes References Other websites Information, Links, History and more of China China Maps

Psychoneuroimmunology (PNI) is the study of the interaction between psychological processes and the nervous and immune systems of the human body. PNI takes an interdisciplinary approach. The main interests of PNI are the interactions between the nervous and immune systems and the relationships between mental processes and health. History Interest in the relationship between psychiatric syndromes or symptoms and immune function has been a consistent theme since the beginning of modern medicine. Claude Bernard, a French physiologist, founded the concept milieu interieur in the mid 1800s. In 1865, Bernard described the perturbation of this internal state “… there are protective functions of organic elements holding living materials in reserve and maintaining without interruption humidity, heat and other conditions indispensable to vital activity. Sickness and death are only a dislocation or perturbation of that mechanism." (Bernard, 1865) Walter Cannon, a professor of physiology at Harvard University coined the term homeostasis in his book The Wisdom of the Body in 1932. In his work with animals Cannon observed that any change of emotional state in the beast, such as anxiety, distress, or rage was accompanied by total cessation of movements of the stomach (Bodily Changes in Pain, Hunger, Fear and Rage, 1915). These studies into the relationship between the effects of emotions and perceptions on the autonomic nervous system, the responses that led to the freeze, fight or flight response. Birth of psychoneuroimmunology In 1975 Robert Ader and Nicholas Cohen advanced PNI with a demonstration of classic conditioning of the immune function, and coined the term "psychoneuroimmunology". Ader was investigating how long conditioned responses might last in laboratory rats. The highly reproducible results showed that conditioned rats exposed to the conditioned stimulus were immuno suppressed. In other words, a signal via the nervous system (taste) was affecting immune function. This was one of the first scientific experiments that demonstrated that the nervous system can affect the immune system. In 1981 David Felten, then working at the Indiana University of Medicine, discovered a network of nerves leading to blood vessels as well as cells of the immune system. The researchers also found nerves in the thymus and spleen terminating near clusters of lymphocytes, macrophages and mast cells, all of which help control immune function. This discovery provided one of the first indications of how neuro-immune interaction occurs. Ader, Cohen and Felten went on to edit the groundbreaking book Psychoneuroimmunology in 1981, which laid out the underlying premise that the brain and immune system represent a single, integrated system of defense. Link between stress and disease Stressors can produce profound health consequences. In one epidemiological study, for example, all-cause mortality increased in the month following a severe stressor – the death of a spouse. Theorists propose that stressful events trigger cognitive and affective responses which, in turn, induce sympathetic nervous system and endocrine changes. These ultimately impair immune function. Potential health consequences are broad, but include rates of infection, HIV progression, and cancer incidence and progression. References Immunology Psychology

A political party is an organized group of people or bodies who seek to capture political power through an election in order to run the affairs of a country. It often puts forward candidates for public office. In a democracy, leaders must "run for office" in an election. In a dictatorship, there is generally only one party allowed, that can approve a new leader without non-members having a choice. About A political party is similar to a faction, and can be the same thing. In some systems, members of one party in the legislature are all expected to vote the same way. The laws written by the party or faction with the majority of votes become adopted by the country, so this means whatever party is elected to over half the seats, gets to run the government. The next largest party is often called the "opposition". Sometimes when there are more than two parties with seats, no one party has over half of the seats. Then two or more parties might join together to form what is called a "coalition". Some parties are formed around a single issue or interest group. Others form policies to address all matters of government, known as a "platform". Many political parties have a set of ideas and beliefs (called its "ideology"). People often describe these ideologies using words such as "conservative" and "liberal". Common ideologies include environmentalism, socialism (ranging from social democracy to Marxism and Communism), conservatism, democracy, liberalism, and nationalism. The law Political parties can be against the law in some places. When some parties get a lot of power, they can make all other political parties illegal. For example, the Nazi Party did this in Germany, and the Communist Party did it in several countries. Some countries make extreme-right parties illegal (such as Vlaams Blok in Belgium). At other times, countries have outlawed far-left parties. For example, West Germany banned the Communist Party in 1956. A handful of countries like China, North Korea and Cuba still have one-party dictatorships. In a few other dictatorships, such as Saudi Arabia, all political parties are banned and there is no parliament at all. Importance in all big democracies In all big democratic countries, parties are very important. But there are a few very small countries, such as the island of Jersey, where most politicians do not belong to any party and where parties do not matter much. In some democracies, there are only two big political parties. For example, in the United States, there is the Democratic Party and the Republican Party. Some other parties exist but are very small and do not hold seats in Congress. In other countries there are larger numbers of parties. In the German federal Parliament (or Bundestag), six parties have seats. In the United Kingdom, there are two big parties, one medium-sized party, and many small ones. Parties in each country List of political parties in Australia List of political parties in Canada List of political parties in France List of political parties in Germany List of political parties in Malaysia List of political parties in New Zealand List of political parties in Pakistan List of political parties in the United Kingdom List of political parties in the United States

A page can be different things: Usually, a page is a physical sheet of paper in a book, magazine, newspaper etc. When a page is not in a book (etc.) it is a sheet or piece of paper. When we talk about computers, a page is also a common abbreviation in net jargon for "webpage". Here the page is not paper, it is a piece of information which we can see on a computer monitor at one time. We can print it to make a real page. But the information may not fit all on one page, and we can not change it when it is printed - we can change a web page. So a webpage is not always the same even as a printed copy of that page. This is a conceptual metaphor. It can be confusing. Someone who uses it is also likely to use other jargon. A page is also a boy or a young man who helps carry things and does small jobs for someone. Another word for this is a pageboy. To page someone is to contact that person on their pager: this is a small electronic machine which makes a sound or gives someone a message. This is usually to call someone for a certain reason, for example: to call them down somewhere, or to ask them for something.

A pet is a domesticated animal that lives with people, but is not forced to work and is not eaten, in most instances. In most cases, a pet is kept to entertain people or for companionship. Some pets such as dogs and cats are placed in an animal shelter if there is no one willing to take care of them. If no one adopts it or the pet is too old/sick, the pet may be euthanized. Dogs, cats, fish, rodents, lagomorphs, ferrets, birds, certain reptiles and amphibians, and a wide variety of arthropods such as tarantulas and hermit crabs are the most common pets in North America. Horses, elephants, oxen, and donkeys are usually made to work, so they are not usually called pets. Some dogs also do work for people, and it was once common for some birds (like falcons and carrier pigeons) to work for humans. Rodents are also very popular pets. The most common are guinea pigs, rabbits, hamsters (especially Syrian and dwarf hamsters), mice and rats. Common Pets

A product can mean a few things: Product (as a general idea) is anything which results from a process. Product (mathematics) is the result of multiplication Product (consumer goods) in business Product (chemistry) is a result or something that is made in a chemical reaction.

The term Program can be used in many ways. A program or programme can be a plan of how to do something. It tells the steps that we think we need to do to make something happen. For example, a government might make a program to improve the health of the people in part of a country by giving the people better food, by helping to kill insects that carry diseases, and by bringing more doctors. A computer program is something a computer uses to work. For example; computer games or web browsers Television program(me) is a show that is on television. Radio program is similar to a television program but it is on the radio. Webcast is similar to a television program but it is shown on the Internet. 12-step program is a way people use to stop doing something. Examples would be to stop drinking alcohol, stop smoking tobacco or stop using drugs. an event program is a thing that lists the what will happen during an event such as an opera or auction.

Platonic realism is the theory of reality developed by Plato, and explained in his theory of Forms. Platonic realism states that the visible world of particular things is a shifting exhibition, like shadows cast on a wall by the activities of their corresponding universal Ideas or Forms. Whereas the visible world of particulars is unreal, the Forms occupy the unobservable yet true reality and are real. Platonism is a similar, yet sometimes modified, view of reality. Origin Among the natural philosophers in ancient Greece, the problem of universals was the mystery of where particular things derive their traits that we perceive as universals—for instance red or apple or good or woman or truth. Plato explained that the particular things of the visible world are imperfect, transient copies of the universal Ideas that are the perfect, lasting Forms. Existing exist outside space and time, the Forms are the universals and act as templates from which particulars manifest. In his Metaphysics, Aristotle, a student of Plato, explained that Socrates and his own student Plato held it significant that the world is in flux, much as Heraclitus had commented, "You cannot step into the same river twice", a theme of the Eleatics, a group of pre-socratic philosophers. Influence Plato's quest Plato considered that only the mind could access the timeless reality of truths, the realm of the Forms casting the visible world. Plato's metaphorical allegory of the cave—whereby humans only know reality as shadows of the real things they see interacting on a wall—suggests the practical consequences of Platonic realism as to natural philosophy in its endeavor to explain the natural world and as to values in human society. (Value theory comprises ethics, aesthetics, and political philosophy.) Plato had led the focused application of geometry, developed by Euclid, to explain the natural world. Yet by his view of nature, Plato regarded astronomy as similar to seeking a theoretical proof in geometry—abstract and not the real world—whereupon the mind's insights derived from a quest to hold other truths through the mind's probing of ethics and aesthetics would yield discovery of truths within the realm of Forms, outside space and time. Aristotle's answer Aristotle, a student of Plato, answered the problem of universals differently. Aristotle explained that universals are concepts corresponding to traits borne and shared by the particular things themselves. Aristotle did not regard all reality as visible, as he recognized existence of souls, yet regarded souls as unobserved parts of the visible world, real in itself. Aristotelianism largely shaped the course of Western thought. Aristotle developed a more or less full description and explanation of the natural world and developed logic—syllogistic logic—to derive conclusions of the relations among things. Aristotle's grounding in the visible world was a metaphysical approach that suggested what evolved by some 2 000 years later into empirical science. Platonism Some mathematicians and physicists are Platonists, for instance Max Tegmark and Roger Penrose. Yet today's Platonists usually view entities within the visible world as real, and simply regard universal abstractions like numbers, sets, propositions, and geometry as corresponding to real and timeless entities that also exist, though pure Platonists regard only the Forms or their realm as real. By way of string theory and the holographic principle, some physicists conjecture that Plato's allegory of the cave approximates the natural world's structure. Tegmark, who regards only the mathematical structure of the universe as real, has been called a radical Platonist. Notes Philosophical movements and positions Reality

A paradox is a sentence in logic that cannot be true but also cannot be false. It is self-contradictory. Many famous problems of this kind exist. Liar's paradox A famous paradox is called the liar's paradox. It is the simple sentence "This sentence is a lie", or equivalently, "This statement is false." If the sentence is true, then it is a lie as it says. But if it is a lie, it cannot be true. A lie cannot also be a truth. So the sentence being true makes it a lie. On the other hand, if the sentence is a lie, then it is not as it says: it is true. But that is just what the sentence says, which makes the content of the sentence true. So the sentence being a lie makes it true. This paradox is not just in English, but in any language. It is true of mathematics as well. Paradox can never be removed from any symbol system that makes claims about itself. Other examples Another example is the statement that "there is no cabal". Only a cabal can know if there is no cabal, so this is either a guess, or, it is a cabal trying to pretend it does not exist. Not all paradoxes are true logical paradoxes, since they can also be common-sense-defying statements that appear true. Some famous examples of this kind of paradox include: Zeno's paradoxes of motion Simpson's paradox in statistics Grandfather paradox Banach–Tarski paradox Informal uses of "paradox" A paradox can also arise in ethics. Assuming power over others may sometimes be required to protect them while diminishing their right to autonomy. This is an ethical dilemma but not a logical paradox. Related pages Contradiction Dilemma Irony Oxymoron Buttered cat paradox Thought experiment References

A potato is a vegetable, the Solanum tuberosum. It is a small plant with large leaves. The part of the potato that people eat is a tuber that grows under the ground. A potato contains a lot of starch and other carbohydrates. Potato usually has a light-brown or yellowish skin and is white or yellow inside. If the potato gets light on it, the tuber turns green and will be poisonous. History The potato is originally from the high and cool areas of the Andes mountains. It was grown as a food crop thousands of years ago. When Spanish conquistadores came to South America in the 1500s they took potatoes back to Europe. It took nearly 200 years for the potato to become a widely grown crop. In the 1780s the farmers in Ireland began growing potatoes because they grew well in the poor soils. They also have most of the vitamins that people need to live. When a potato plague destroyed the crop in 1845 the Irish Potato Famine killed many people. The potato plant is now grown in many different parts of the world. Captain William Bligh planted potatoes on Bruny Island, Tasmania in 1792. In Australia they are now the largest vegetable crop. Name origin The English word "potato" comes from the Spanish word "patata". The Royal Spanish Academy says the Spanish word is a hybrid of the Taíno ('sweet potato') and the Quechua ('potato'). Types Yukon Gold – developed in Canada Norgleam Bismark Coliban Russet Pontiac Sequoia Desiree – cream colored flesh, red skin Bintje Irish grown Scientists in Germany have used genetic engineering to make a potato called the Amflora, which could be grown to make starch for making other things in factories. Cooking Potatoes are almost always eaten cooked. People cook potatoes by boiling, baking, roasting, or frying them. French fries or "chips" are potatoes cut into long pieces and fried until they are soft. Potato chips, often called crisps, are potatoes cut into very thin round pieces and fried until they are hard. William Shakespeare wrote that the potato was an aphrodisiac, but there is no evidence to show this is true. References Solanum

Plants are one of five big groups (kingdoms) of living things. They are autotrophic eukaryotes, which means they have complex cells, and make their own food. Usually they cannot move (not counting growth). Plants include familiar types such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant (living) species of plants. Fungi and non-green algae are not classified as plants. Most plants grow in the ground, with stems in the air and roots below the surface. Some float on water. The root part absorbs water and some nutrients the plant needs to live and grow. These climb the stem and reach the leaves. The evaporation of water from pores in the leaves pulls water through the plant. This is called transpiration. A plant needs sunlight, carbon dioxide, minerals and water to make food by photosynthesis. A green substance in plants called chlorophyll traps the energy from the Sun needed to make food. Chlorophyll is mostly found in leaves, inside plastids, which are inside the leaf cells. The leaf can be thought of as a food factory. Leaves of plants vary in shape and size, but they are always the plant organ best suited to capture solar energy. Once the food is made in the leaf, it is transported to the other parts of the plant such as stems and roots. The word "plant" can also mean the action of putting something in the ground. For example, farmers plant seeds in the field. Photosynthesis happens in the leaves on the plant. The leaves are the only parts of a plant that can do this. This is also known as how the plant gets its food.You can make the process quicker by adding more CO2, light and chlorophyll. Types of plants Green algae: Chlorophyta Charophyta Land plants (embryophyte) Non-vascular plants (bryophytes): Liverworts Mosses Hornworts †Horneophytopsida Vascular plants (tracheophytes) Lycopodiophyta—clubmosses Pteridophyta: the ferns Pteridopsida: the typical ferns Sphenopsida: the horsetails Marattiopsida: a divergent group of ferns Psilotopsida sister-group to all other ferns †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls †Trimerophytophyta—trimerophytes †Progymnospermophyta Seed plants (spermatophytes) †Pteridospermatophyta: the seed ferns Pinophyta: the conifers Cycadophyta: the cycads Ginkgophyta: the ginkgos Gnetophyta: sister group to the Angiosperms Magnoliophyta or Angiosperms (flowering plants) Dicotyledons Monocotyledons †Nematophytes The plant food factory At least some plant cells contain photosynthetic organelles (plastids) which enable them to make food for themselves. With sunlight, water, and carbon dioxide, the plastids make sugars, the basic molecules needed by the plant. Free oxygen (O2) is produced as a by-product of photosynthesis. Later, in the cell cytoplasm, the sugars may be turned into amino acids for proteins, nucleotides for DNA and RNA, and carbohydrates such as starch. This process needs certain minerals: nitrogen, potassium, phosphorus, iron and magnesium. Plant nutrients Plant nutrition is the study of the chemical elements that are necessary for plant growth. Macronutrients: N = Nitrogen (Carbohydrates, amino acids & glycolipids) P = Phosphorus (ATP and the energy cycle) K = Potassium (water regulation, opening and closing of stomata in some plant species) Ca = Calcium (transport of other nutrients) Mg = Magnesium (major constituent of chlorophyll, activator to various enzymes) S = Sulfur (some amino acids) Si = Silicon (cell walls) Micronutrients (trace elements) include: Cl = Chlorine (osmosis and ion balance) Fe = Iron (photosynthesis ans enzyme co-factor) B = Boron (sugar transport and cell division) Mn = Manganese (building chloroplasts) Na = Sodium (various) Zn = Zinc (activator to many enzymes) Cu = Copper (photosynthesis) Ni= Nickel (an enzyme) Mo = Molybdenum (enzyme co-factors) Roots The roots of plants perform two main functions. First, they anchor the plant to the ground. Second, they absorb water and various nutrients dissolved in water from the soil. Plants use the water to make food. The water also provides the plant with support. Plants that lack water become very limp and their stems cannot support their leaves. Plants which specialise in desert areas are called xerophytes or phreatophytes, depending on the type of root growth. Water is transported from the roots to the rest of the plant through special vessels in the plant. When the water reaches the leaves, some of it evaporates into the air. Many plants need the help of fungi to make their roots work properly. This plant/fungi symbiosis is called mycorrhiza. Rhizobia bacteria in root nodules help some plants get nitrogen. Flowering plant reproduction Flowers and pollination Flowers are the reproductive organ only of flowering plants (Angiosperms). The petals of a flower are often brightly colored and scented to attract insects and other pollinators. The stamen is the male part of the plant. It is composed of the filament (a stalk) that holds the anther, which produces the pollen. Pollen is needed for plants to produce seeds. The carpel is the female part of the flower. The top part of the carpel contains the stigma. The style is the neck of the carpel. The ovary is the swollen area at the bottom of the carpel. The ovary produces the seeds. The sepal is a leaf that protects a flower as a bud. How pollen moves from one flower to another flower is called pollination. This transfer can happen in different ways. Insects such as bees are attracted to bright, scented flowers. When bees go into the flower to gather nectar, the spiky pollen sticks to their back legs. The sticky stigma on another flower catches the pollen when the bee lands or flies nearby it. Some flowers use the wind to carry pollen. Their dangling stamens produce lots of pollen that is light enough to be carried by the wind. Their flowers are usually small and not highly coloured. The stigmas of these flowers are feathery and hang outside the flower to catch the pollen as it falls. Seed travelers A plant produces many spores or seeds. Lower plants such as moss and ferns produce spores. The seed plants are the Gymnosperms and Angiosperms. If all the seeds fell to the ground besides the plant, the area might become overcrowded. There might not be enough water and minerals for all the seeds. Seeds usually have some way to get to new places. Some seeds can be dispersed by the wind or by water. Seeds inside juicy fruits are dispersed after being eaten. Sometimes, seeds stick to animals and are dispersed that way. Fossils The question of the earliest plant fossils depends on what is meant by the word "plant". If by plants we mean phototrophs using chlorophyll, then cyanobacteria in stromatolites are the first fossils, 3,450 million years ago (mya) in the Archaean eon. The remarkable precision is possible because the fossils were sandwiched between lava flows that could be precisely dated from embedded zircon crystals. If by plants we include all types of algae, then the earliest known red algae lived 1.6 billion years ago. Fossils of them were recently found in India. If by plants we mean green plants, Viridiplantae, then the first fossils are green algae. This is probably the majority position amongst professional botanists. There is convincing evidence for the monophyly of charophyte green algae and embryophytes. There are still two choices: Acritarchs (a group of organic-walled microfossils) may be reproductive cysts of green algae. If so, they are present in the Neoproterozoic era, 1000 mya. Otherwise, there is a large increase in planktonic algae around 540 mya in the Cambrian period. If by plants we mean land plants, the first fossils are in the Silurian. By the Silurian, fossils of whole plants are preserved, including the lycophyte Baragwanathia. From the Devonian, detailed fossils of rhyniophytes have been found. Early fossils of these ancient plants show the individual cells within the plant tissue. The Devonian period also saw the evolution of the first tree in the fossil record, Wattezia. This fern-like tree had a trunk with fronds, and produced spores. The coal measures are a major source of Palaeozoic plant fossils, with many groups of plants in existence at this time. The spoil heaps of coal mines are the best places to collect; coal itself is the remains of fossilised plants, though structural detail of the plant fossils is rarely visible in coal. In the Fossil Forest at Victoria Park in Glasgow the stumps of Lepidodendron trees are found in their original growth positions. Related pages Spore Seed Germination References Basic English 850 words

A prediction is a statement that someone makes about what they think is going to happen. It is often very helpful to know what is going to happen to help prepare for these future events. Predictions are based on the idea that two beginning positions that are like each other will have similar results. By watching something happen, it is possible to predict what will happen if something similar happens. Predictions are given by science or fortune tellers or horoscopes. The most common example of a prediction is the weather forecast. Studying how weather happens lets people predict what the weather will be by looking at what is currently happening. This is helpful because by knowing that it is going to rain, a person can wear the right clothes for it. Nostradamus has made many predictions about the future. Everyday life

Probability is a part of applied mathematics. It has to do with chance, the study of things that might happen or might not happen. For example, using probability, one can show that by throwing a coin up in the air and letting it land, half of the time it will land with one side facing up, and half of the time with the other side facing up. Many coins have a picture of the face of a famous person on one side, and something else on the other side. Often people call the side with the face "heads", and the other side "tails". The probability (p) of an event E, written , is always between zero (impossible) and one (certain). If we roll a die (plural: dice), then the chance that it will land on 1 is 1/6 (because there are 6 numbers on a die). Similarly, the chance it will land on 2 is also 1/6. The chance it will land on any number between 1 and 6 is 1, because every time we roll the die, it will always land on a number between 1 and 6. Probability can be figured out using mathematics. For example, if one rolls six dice, the chance of them getting a number more than ten is not obvious, but can be figured out using math and science. One of the most interesting things about chance is that to figure out the probability that two things will both happen, one usually multiply their two probabilities together. For example, suppose that one wants to know the probability of rolling two dice and getting a certain combination (it could be two 6s or a 3 then a 5, just any two). The possibility of getting a 3 is one in six (⅙), and the possibility of getting a 5 is also one in six, so the chances of getting a 3 then a 5 is ⅙×⅙=⅟36. If that number is expressed as somewhere between 0 and 1, it equals 0.027...7, which is fairly low. The possibility of getting a 3, then a 5, and then a 2 would be ⅙×⅙×⅙=⅟216 or 0.00463, which is a much lower probability. Ideas of probability People like Jacob Bernoulli, Pierre-Simon Laplace, or Christiaan Huygens used the word probability, as described above. Other people thought about frequencies; the notion of probability is usually called frequency probability. Related pages List of mathematics topics Probability density function Probability distribution Probability space Probability theory Random Random variable Stochastic process References Probability theory

A probability experiment is a situation where chance affects the result of an experiment. If the experiment can only have two outcomes, it is named Bernoulli trial. A coin flip is a probability experiment because chance affects whether a coin will land heads or tails when it is flipped. Probability theory Experiments

Proteins are long-chain molecules built from small units known as amino acids. They are joined with peptide bonds. They are biochemical compounds consisting of one or more polypeptides folded into a round or fibrous shape. A polypeptide is a single linear polymer chain of amino acids. The sequence of amino acids in a polypeptide comes from the DNA sequence of a gene. The genetic code specifies 20 standard amino acids. Shortly after synthesis, some amino acids are chemically modified. This alters the folding, stability, activity, and function of the protein. Sometimes proteins have non-peptide groups attached, as cofactors. Proteins are essential to all cells. Like other biological macromolecules (polysaccharides and nucleic acids), proteins take part in virtually every process in cells: Many proteins are enzymes that catalyze (help to happen) biochemical reactions and are vital to metabolism. Other proteins have structural or mechanical functions, such as in muscle and in cells. The cytoskeleton is a system of scaffolding that keeps cell shape. Other proteins are important in cell signalling, immune responses, and cell division Formation Proteins are formed via a process called "Protein synthesis". In this process the cell reads the genetic information of the DNA and translates it into a protein. In eukaryotes, this process begins in the Nucleus and ends in the ribosome. In procaryotes all of it is done in the cytoplasm. The general concept is exactly the same for every living being. In humans Proteins have different functions depending on their shape. They can be found in meat or muscle. They are used for growth and repair, as well as for strengthening the bones. They help to make tissue and cells. They are in animals, plants, fungi, bacteria, and also in the human body. Muscles contain a lot of protein. When protein is digested, it is broken down into amino acids. These amino acids can then be used to build new protein. Proteins form an important part in foods like milk, eggs, meat, fish, beans, spinach, and nuts. There are four factors that determine what a protein will do. The first is the order of the amino acids. There are 20 different types of amino acids. The second is the little twists in the chain. The third is how the entire structure is folded up. The fourth is whether it is made up of different sub-units. Haemoglobin molecules, for example, are made of four sub-units. Damaging mutations Most proteins are enzymes, and mutations may slow them or stop them working. 50% of human cancers are caused by mutations in the tumour suppressor p53. p53 is a protein which regulates cell division. Essential amino acids Proteins are necessary in an animal's diets, since animals cannot make all the amino acids they need (they can make most of them). They must get certain amino acids from food. These are called the essential amino acids. Through digestion, animals break down ingested protein into free amino acids. The amino acids are then used in metabolism to make the enzymes and structures the body needs. There are nine essential amino acids for humans, which are obtained from food. The nine essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Meat contains all the essential amino acids humans need; most plants do not. However, eating a mixture of plants, such as both wheat and peanut butter, or rice and beans, provides all the essential amino acids needed. Soy products like tofu provide all the essential amino acids—as does quinoa—but these are not the only way to get the protein humans need. The scientist Jöns Jacob Berzelius gave proteins their name, but many other scientists have studied proteins. Related pages Protein structure Protein folding Translation (genetics) References Other websites Protein from the Harvard School of Public Health Molecular biology

The periodic table is the systematic and tabular arrangement of all known chemical elements in which elements having similar properties kept together. In the table, the elements are placed in the order of their atomic numbers starting with the lowest number of one, hydrogen. The atomic number of an element is the same as the number of protons in that particular nucleus of an atom. In the periodic table the elements are arranged into periods and groups. A row of elements across the table is called a period. Each period has a number; from 1 to 8. Period 1 has only 2 elements in it: hydrogen and helium. Period 2 and Period 3 both have 8 elements. Other periods are longer. Elements in a period have consecutive atomic numbers. A column of elements down the table is called a group. There are 18 groups in the standard periodic table. Each group has a number: from 1 to 18. Elements in a group have electrons arranged in similar ways, according to the number of valency electrons, which gives them similar chemical properties (they behave in similar ways). For example, group 18 is known as the noble gases because they are all gases and they do not combine with other atoms. There are two systems of group numbers; one using Arabic numerals (1,2,3) and the other using Roman numerals (I, II, III). The Roman numeral names were used in most of the 20th century. In 1990 the International Union of Pure and Applied Chemistry (IUPAC) decided to use the new system with Arabic numerals, to replace the two old group systems that used Roman numerals. The periodic table has been used by chemists to observe patterns and relationships between elements. There are 3 main groups in the Periodic Table; metals, metalloids, and nonmetals. For example, elements to the bottom and far left of the table are the most metallic, and elements on the top right are the least metallic. (e.g. cesium is much more metallic than helium). There are also many other patterns and relationships. The periodic table was invented by the Russian chemist Dmitry Ivanovich Mendeleyev (18341907). In his honor, element 101 was named after him, mendelevium. Standard periodic table Chemical Series of the Periodic Table Alkali metals Alkaline earths Lanthanides Actinides Superactinides Transition metals Poor metals Metalloids/Semi metals/Half metals Nonmetals Halogens Noble gases State at standard temperature and pressure. The color of the number (atomic number) above the element symbol shows the state of the element at normal conditions. those in blue are gases those in green are liquids those in black are solid Radioactivity Those with solid borders have stable isotopes (Primordial elements) Those with dashed borders have only radioactive naturally occurring isotopes Those with dotted borders do not occur naturally (Synthetic Elements) Those without borders are too radioactive to have been discovered yet. Other methods for displaying the chemical elements The version of the periodic table shown above is the one most used. Other widespread versions are shown below: Other versions The standard table provides the basics. It is shown above A vertical table for improved readability in web browsers The big table provides the basics plus full element names The huge table provides the basics plus full element names and atomic masses Electron configurations Metals and Non Metals List of elements: includes name, symbol, atomic number, atomic mass, group, and period; sortable by any of those List of elements by symbol List of elements by boiling point List of elements by melting point List of elements by density Related pages Periodic table group Periodic table period Extended periodic table Other websites Periodic Table of the Elements – displays basic properties WebElements Periodic table

Physiology is the study of how living things work. Physiologists can study how organs of an organism work together to make things happen. In human beings, for example, the digestion of food hormones and other chemicals are made by the stomach, liver, and pancreas. Muscle contraction happens because of chemical messages made by nerves of that muscle. By learning how the body functions normally, physiologists and physicians can better understand what happens when organs do not function normally. For example, an understanding of how the thyroid gland functions has helped in treating goitre. Studies of the circulatory system and the nervous system have helped physicians understand and treat such illnesses like heart disease, stroke, and high blood pressure. The field is usually divided into human physiology, animal physiology, and plant physiology. References Other websites The Physiological Society Developmental physiology The American Physiological Society

A planet is a large object such as Venus or Earth that orbits a star. Planets are smaller than stars, and they do not make light. Jupiter is the biggest planet in the Solar System. Planets are shaped like a slightly squashed ball (called a spheroid). Objects that orbit planets are called satellites. A star and everything which orbits it are called a star system. There are eight planets in the Solar System. Pluto used to be called a planet, but in August 2006, the International Astronomical Union decided it was a dwarf planet instead. There are four more known dwarf planets in the Solar System, Ceres, Makemake, Eris and Haumea. The name "planet" is from the Greek word πλανήτης (planetes), meaning "wanderers", or "things that move". Until the 1990s, people only knew the planets in the Solar System. 4,905 extrasolar planets (exoplanets) have been discovered in 3,629 planetary systems (January 2022 data). The count includes 808 multi-planetary systems. Known exoplanets range in size from gas giants about twice as large as Jupiter down to just over the size of the Moon. About 100 of these planets are roughly the size as Earth. Nine of these orbit in the habitable zone of their star. Origin of the planets The planets are made of elements that are mostly different from the Sun (which is mostly hydrogen). The Sun is mostly made up of hydrogen, with some helium. Its energy comes from converting hydrogen to helium. In contrast, the planets are mostly made up of larger atoms and molecules which could not have come from the Sun. The materials of planets must have come from another source or sources. Those sources were atoms made in earlier supernovae explosions near the Sun's path as it moved through its part of the Milky Way. The material captured by the Sun's gravity formed the planets. The same thing happened in other planetary systems in the galaxy. The gas giants are made up of hydrogen gas like the Sun, plus (at their centres) "metallic" elements like the terrestrial planets. Historical names The planets in the Solar System have names of Greek or Roman gods, except for Earth, because people did not think Earth was a planet in old times. However, Earth is occasionally referred by the name of a Roman god: Terra. Other languages, for example Chinese, use different names. Moons also have names of gods and people from classical mythology. The names of the moons of Uranus are from the plays written by Shakespeare. Planets Here is a list of planets in the Solar System from the closest to the farthest Types of planets There are planets, and smaller objects that also go around the Sun. Some examples of smaller objects are asteroids, comets, and trans-Neptunian objects. There are three types of planets in the Solar System. They are: Terrestrial or rocky: These are planets that are like Earth. They are mostly made up of rocks. They include: Mercury, Venus, Earth, Mars. Jovian or gas giant: These planets are mostly made of gas in their outer layers. They all have metallic cores. They include: Jupiter, Saturn, Uranus, Neptune. Icy: These planets are mostly made of ice. It includes Pluto. Many objects in the Solar System that are not planets are also "icy". Examples are the icy moons of the outer planets of the Solar System (like Triton). Related pages Formation and evolution of the Solar System List of planets Ice dwarfs References

Many people say the government stops people from having freedom of speech, freedom of religion and other political rights that people in other countries have. China still has one-party rule, and is not a democracy. Territorial disputes The following territories are claimed by China (PRC and/or ROC) and by another country or more. Diaoyu Islands (with Japan) Nansha Archipelago (with Vietnam, Brunei, Malaysia, and the Philippines) Xisha Archipelago (with Republic of China and Vietnam) South Tibet - parts of Arunachal Pradesh (with Republic of India) Aksai Chin - part of Kashmir (with Republic of India) Lost territories (Unequal treaties) Unequal treaties were forced onto Asian countries when European imperialism reached Asia. The list includes claims from PRC and ROC, as well as unofficial historical claims. Note: Japan's and Korea's unequal treaties have been resolved since the end of WWII. Mongolia (lost to independence) Tuva (lost to Russian Empire) Outer Manchuria (lost to Russian Empire) Kyrgyzstan (lost to Russian Empire) parts of Kazakhstan (lost to Russian Empire) parts of Myanmar (lost to British Empire) Bhutan (lost to British Empire) Hong Kong (lost to British Empire) (returned to PRC with effect from 1 July 1997 under the Sino-British Joint Declaration) Macau (lost to Portugal) (transferred to PRC on 20 December 1999) Tonkin & Northern Annam (lost to France) Ryukyu Islands (lost to Japanese Empire) See also Movies banned in China 1989 Tiananmen Square protests Politics of China

Police are a group of people whose job is to enforce laws, help with emergencies, solve crimes and protect property. A person who carries out this duty is known as a police officer. They work out of a police station. Police are trained in first aid and rescue, because police officers are often one of the first people to get to a place where people are sick or injured, such as a car accident, or a fire. Naming A police agency may be called a police force, police department, police service, constabulary, civil guard or protective service. A gendarmerie is a police force that is part of the military, although its members rarely do actual military work. Most police forces in the United States name themselves as "[Place] Police Department", such as New York City Police Department. State police forces are usually known as either "[State] Highway Patrol" or "[State] State Police". In the United Kingdom, most are "[Place] Police" or "[Place] Constabulary". In Canada and other English-speaking countries, "[Place] Police Service" is common. Ireland's police are called the Garda Síochána. A law enforcement agency is any agency that enforces the law. In the United States, there are some law enforcement agencies that are not called police forces but carry out similar work, such as the Federal Bureau of Investigations. One common type is a sheriff's office (also sheriff's department), an agency that is led by a sheriff. Those who carry out policing duties are known as police officers. They may also be known as policemen Powers The police have different powers to help them do their job. These powers are different in different countries. Most police officers have the power to arrest people, search people, and search houses/properties. They sometimes carry equipment such as guns, batons, tasers, or pepper spray. The area where police officers can use these powers is called their jurisdiction. If officers are outside of their jurisdiction, another police force with jurisdiction can then use their powers. Duties The police deal with: Preventing crime and protecting the public. They do this by patrolling on foot in uniform and in police cars. This can stop some forms of criminal behavior. Responding to crimes. When someone calls the police to say that a crime is happening, they must send some police officers to arrive at the scene very quickly. They will try to stop the crime and catch the person doing it. Investigating crime. This means that the police try to find out who did the crime. Arresting and detaining suspects. When the police believe that someone has committed a crime, the police arrest them, take them to the police station and ask them questions. However, it is the prosecutors and not the police who have the final say on whether a suspect gets charged. To help with emergencies or problems that are not crimes. This may be car accidents, fires, or people who are sick, hurt or lost. The police work with firefighters, ambulances, and rescuers. They might direct traffic, help lost children, or give traffic tickets. Parts of police departments Most police departments have officers in two main groups: a "patrol" group with officers who wear uniforms, and a "detective" group with officers who wear normal clothing. Patrol officers travel through their area. They may travel by foot, on bicycle or motorcycle, or in marked cars. The cars have warning lights and sirens that can be used. The sirens make a loud sound. Patrol officers enforce motor vehicle and criminal laws. In some locations patrol officers manage the local jail. Detectives work on investigations that are more complex. They try to find fraud, illegal drugs, and sex crimes like prostitution, human trafficking, and rape. Prostitution is not a crime in all countries. Not all countries use the same words to describe these groups. In the United Kingdom, for example, patrol officers form the "uniform branch", while detectives work within the CID ("Criminal Investigation Department"). Also in the United Kingdom, not all police officers are armed, these police officers form an "Armed Response Unit" which comes under other names in different constabularies, in the Metropolitan Police Service, it falls under SFC (Specialist Firearms Command) which all MET Armed Police fall under Police uniforms, equipment and methods vary depending on the country. In some places, groups of police train for special jobs such as dealing with riots or dealing with highly dangerous criminals. Police in different countries Different countries have different ways of organizing their police. Some countries like South Africa, Ireland and New Zealand have just one police force. Other countries have more than one. France has two police forces, one for cities and another for rural areas. Chile also has two, one for patrol and another for investigations. Some countries have two or more levels of police forces. For example, most policing in Australia is carried out by the six state police forces, but there is also the Australian Federal Police who police the whole country. Germany has a similar system. The United Kingdom and Switzerland have many local police forces and several national agencies, but no actual national police force. In Canada, local governments can choose to either run their own police force or give the job to a bigger one. So most Canadian cities have their own police, while most rural areas are policed by the Royal Canadian Mounted Police, which is also the national police. The United States has over 17,000 law enforcement agencies. Many areas have four levels of law enforcement agencies. For example, Los Angeles has the Los Angeles Police Department but there are many other agencies that can work in the city. This includes the county-level Los Angeles Sheriff's Department, the state-level California Highway Patrol and over 100 federal (or national) law enforcement agencies. Worldwide, police are a small percentage of the number of people they serve. On average there are 303.3 police officers per 100,000 people. Equipment In most countries, police officers carry guns during their normal duties. In the United Kingdom, New Zealand, Ireland and a few other countries, most police officers do not carry guns. Officers may also carry pepper spray, electric shock weapons (such as tasers), and batons for defense. Police officers also wear handcuffs to detain suspects. Officers communicate using radio devices. The radios can be on both the uniform and in the patrol vehicle. Related pages Police officer SWAT team References Other websites 1860-1870 picture of San Fransico Police man Police History book Police Pictures links Law Emergency services

The number () is a mathematical constant that is the ratio of a circle's circumference to its diameter. This produces a number, and that number is always the same. However, the number is rather strange. The number starts as 3.141592653589793... and continues without end. Numbers like this are called irrational numbers. The diameter is the largest chord which can be fitted inside a circle. It passes through the center of the circle. The distance around a circle is known as the circumference. Even though the diameter and circumference are different for different circles, the number pi remains constant: its value never changes. This is because the relationship between the circumference and diameter is always the same. Fundamentals Definition is commonly defined as the ratio of a circle's circumference to its diameter : Approximate value Pi is often written as , or the Greek letter π as a shortcut. Pi is also an irrational number, meaning it cannot be written as a fraction (), where 'a' and 'b' are integers (whole numbers). This basically means that the digits of pi that are to the right of the decimal go forever—without repeating in a pattern, and that it is impossible to write the exact value of pi as a number. Pi can only be approximated, or measured to a value that is close enough for practical purposes. A value close to pi is 3.141592653589793238462643... A common fraction approximation of pi is , which yields approximately 3.14285714. This approximation is 0.04% away from the true value of pi. While this approximation is accepted for most of its use in real life, the fraction is more accurate (giving about 3.14159292), and can be used when a value closer to pi is needed. Computers can be used to get better approximations of pi. In March 2019, Emma Haruka Iwao calculated the value of pi to 31.4 trillion digits. History Mathematicians have known about pi for thousands of years, because they have been working with circles for the same amount of time. Civilizations as old as the Babylonians have been able to approximate pi to many digits, such as the fraction 25/8 and 256/81. Most historians believe that ancient Egyptians had no concept of π, and that the correspondence is a coincidence. The first written reference to pi dates to 1900 . Around 1650 , the Egyptian Ahmes gave a value in the Rhind Papyrus. The Babylonians were able to find that the value of pi was slightly greater than 3, by simply making a big circle and then sticking a piece of rope onto the circumference and the diameter, taking note of their distances, and then dividing the circumference by the diameter. Knowledge of the number pi passed back into Europe and into the hands of the Hebrews, who made the number important in a section of the Bible called the Old Testament. After this, the most common way of trying to find pi was to draw a shape of many sides inside any circle, and use the area of the shape to find pi. The Greek philosopher Archimedes, for example, used a polygon shape that had 96 sides in order to find the value of pi, but the Chinese in 500 were able to use a polygon with 16,384 sides to find the value of pi. The Greeks, like Anaxagoras of Clazomenae, were also busy with finding out other properties of the circle, such as how to make squares of circles and squaring the number pi. Since then, many people have been trying to find out more and more exact values of pi. In the 16th century, better and better ways of finding pi became available, such as the complicated formula that the French lawyer François Viète developed. The first use of the Greek symbol "π" was in an essay written in 1706 by William Jones. A mathematician named Lambert also showed in 1761 that the number pi was irrational; that is, it cannot be written as a fraction by normal standards. Another mathematician named Lindeman was also able to show in 1882 that pi was part of the group of numbers known as transcendentals, which are numbers that cannot be the solution to a polynomial equation. Pi can also be used for figuring out many other things beside circles. The properties of pi have allowed it to be used in many other areas of math besides geometry, the study of shapes. Some of these areas are complex analysis, trigonometry, and series. Pi in real life There are different ways to calculate many digits of π. This is of limited use though. Pi can sometimes be used to work out the area or the circumference of any circle. To find the circumference of a circle, use the formula C (circumference) = π × (diameter). To find the area of a circle, use the formula π (radius²). This formula is sometimes written as , where r is the variable for the radius of any circle and A is the variable for the area of that circle. To calculate the circumference of a circle with an error of 1 mm: 4 digits are needed for a radius of 30 meters 10 digits for a radius equal to that of the earth 15 digits for a radius equal to the distance from the earth to the sun. 20 digits for a radius equal to the distance from the earth to Polaris. People generally celebrate March 14 as Pi Day, because March 14 is also written as 3/14, which represents the first three numbers 3.14 in the approximation of pi. Pi day started during 2001. Related pages List of numbers Irrational numbers Square root of 2 Golden ratio E (mathematical constant) Squaring the circle Transcendental number References Geometry Irrational numbers Transcendental numbers Mathematical constants

A proper noun or proper name is a noun representing a unique thing (such as London, Jupiter, John Hunter, or Toyota), as opposed to a common noun, which represents a class of things (for example, city, planet, person or corporation). Proper nouns are the only nouns in English which have the first letter capitalized. In English, proper nouns are not normally preceded by an article or other limiting modifier (such as any or some), and are used to denote a particular person, place, or object without regard to any descriptive meaning the word or phrase may have (for example, a town called "Newtown" may be, but does not necessarily have to be, a new [recently built] town). Which nouns are considered proper names depends on language. For example, names of days and months are considered proper names in English, but not in Spanish, French, Swedish, Slovenian or Finnish, where they are not capitalized. References Parts of speech no:Substantiv#Egennavn vs. fellesnavn

A plastic is a material that can change its shape easily. Many things are made of plastics, some types of wood can be made out of plastic, usually because making them to the right shape is easy and plastic, gives form to wood and other things. There are many types of plastic. Some can be shaped only when they are freshly made; then they become hard. Others are thermoplastic and can be softened by heating them. These plastics can be used for 3D printing, because the plastic will become soft enough to form into different shapes, and then become hard again when they cool down. Most plastics are man-made; they do not occur in nature. The process of making plastics is usually quite complicated. Most of the materials that are called plastic are polymers. Polymers are long chains of atoms bonded to each other. In most plastics, the long chain is a chain of carbon atoms with other atoms attached to them. The different atoms and the shape and length of the chains change how the plastic looks and works. People experimented with plastics based on natural polymers for a very long time. Alexander Parkes, an English inventor (1813-1890), created an early form of plastic in 1855. It was hard but flexible and transparent. He called it "Parkesine" but now it is called "Celluloid." Old plastics are usually thrown away and put in landfills. Some plastics release toxic fumes when heated. Some plastics are recycled so they won't become waste. Some plastics have other materials added to them, like glass, because they make the plastic stronger and stiffer. Plastics are mostly petrochemicals, made from natural gas or from petroleum, a type of oil. Chemical engineers refine the petroleum which goes through a heating process. It develops ethylene and propylene, which are the chemical building blocks for many plastics. These chemicals are then combined with other chemicals to produce a polymer. Today, some of these plastics are also being made without oil. Instead, other sources like plants and bacteria are used to make the plastic. These plastics are called bioplastics. They are useful because they can be eaten by other bacteria instead of throwing them away. Well-known plastics, and their use Polyamide (usually called nylon) Women's stockings, gears, car parts, toothbrush bristles Polycarbonate – bulletproof glass, compact discs, DVDs. Polyethylene – tubes, bottles, shopping bags, milk jugs, body armor (made with polyethylene with especially long chains) Polyethylene terephtalate (called PET when used for bottles, and polyester when used for clothes or other materials) Polypropylene - food containers, chairs Polystyrene - CD cases, plastic cups, plastic forks and knives Polyurethane - rubber, foam, shiny coatings on wood and tile Polyvinyl chloride (called PVC, usually) - pipes (chemicals can make PVC softer for toys and cushions) References Polymers Polymer chemistry

Product stewardship includes waste disposal measures in the distribution of an industrial product. That is, paying for the safe and proper disposal when you pay for the product, and relying on those who sold it to you, to dispose of it. The slightly more specific idea of product take-back means that the service of waste disposal is paid for at time of purchase. It is often applied to paint, tires, and other goods that become toxic waste if not disposed of properly. It is most familiar as the deposit bottle - where one pays for the loan of the bottle at the same time as one purchases what is inside it. The container deposit charged for a deposit bottle may be a fee to buy the bottle, separately from the fee to buy what it contains. If one returns the bottle, the fee is returned, and the supplier must return the bottle for re-use or recycling. If not, one has paid the fee, and presumably this can pay for landfill or litter control measures that dispose of say a broken bottle. Also, since the same fee can be collected by anyone finding and returning the bottle, it is common for people to collect these and return them as a means of surviving. This is quite common for instance among homeless people. Legal requirements vary: the bottle itself may be considered simple property of the purchaser of the contents, or, the purchaser may have some obligation to return the bottle to some depot so it can be recycled or re-used. For the more toxic items, it is more likely that returning it is required: This principle is applied very broadly beyond bottles to paint and automobile parts such as tires. When purchasing paint or tires in many places, one simultaneously pays for the disposal of the toxic waste they become. In some countries, such as Germany, law requires attention to the comprehensive outcome of the whole extraction, production, distribution, use and waste of a product, and holds those profiting from these legally responsible for any outcome along the way. This is also the trend in the UK and EU generally. In the United States, there have been many class action suits that are effectively product stewardship liability - holding companies responsible for things the product does, which it was never advertised to do. Rather than let liability for these problems be taken up by the public sector or be haphazardly assigned one issue at a time to companies via lawsuits, many accounting reform efforts focus on achieving full cost accounting. This is the financial reflection of the comprehensive outcome - noting the gains and losses to all parties involved, not just those investing or purchasing. Such moves have made moral purchasing more attractive, as it avoids liability and future lawsuits. So these are partial implementations of a strict service economy ideal. Those who advocate these measures are concerned with the later phases of product lifecycle and the comprehensive outcome of the whole production process. It is considered a pre-requisite to a strict service economy interpretation of (fictional, national, legal) "commodity" and "product" relationships. Business Ethics

Peace is a time without any fights or wars. In a larger sense, peace (or peacefulness) can mean a state of harmony, quiet or calm that is not disturbed by anything at all, like a still pond with no ripples. Many people and organizations want peace. One organization that was set up to bring peace among the nations and try to make war a thing of the past was the League of Nations after World War I. When it did not stop World War II, it was replaced by the United Nations which tries to make the world peaceful. This means that if any member is attacked or invaded by another country without attacking that country first, the other members will come to help the country that was attacked first. This idea was used by the United Nations to defend both South Korea and Kuwait when they were attacked. Martin Luther King, Jr. wrote in a letter he sent from the Birmingham jail that, "True peace is not merely the absence of tension: it is the presence of justice." In other words, Real peace is more than just problems being gone: there must be fairness to have peace. Alfred Nobel created an annual award, the Nobel Peace Prize, for the person who had done the most to bring peace to the world. Religious beliefs and peace Buddhists think that peace can be gotten once all suffering ends.To get rid of suffering and get this peace, many try to follow a set of teachings called the Four Noble Truths Jews and Christians believe that true peace comes from a personal relationship with God. Jesus Christ (also called the "Prince of Peace" in the Book of Isaiah) said: "Peace I leave with you; my peace I give you. I do not give to you as the world gives. Do not let your hearts be troubled and do not be afraid." () Inner peace Inner peace (or peace of mind) refers to a state of being mentally and spiritually at peace, with enough knowledge and understanding to keep oneself strong in the face of stress. Being "at peace" is considered by many to be healthy and the opposite of being stressed or anxious. Peace of mind is generally associated with bliss and happiness. Peace of mind, serenity, and calmness are descriptions of a disposition free from the effects of stress. In some cultures, inner peace is considered a state of consciousness or enlightenment that may be cultivated by various forms of training, such as prayer, meditation, Tai chi chuan or yoga, for example. Many spiritual practices refer to this peace as an experience of knowing oneself. Movements and activism Peace movement A movement that seeks to get ideals such as the ending of a particular war, minimize inter-human violence in a particular place or type of situation, often linked to the goal of achieving world peace. Means to achieve these ends usually include advocacy of pacifism, non-violent resistance, conscientious objector, diplomacy, boycotts, moral purchasing, supporting anti-war political candidates, demonstrations, and lobbying to create legislation on human rights or of international law. Theories on peace Many different theories of "peace" exist in the world of peace studies, which involves the study of conflict transformation. The definition of "peace" can vary with religion, culture, or subject of study. Peace is a state of balance and understanding in yourself and between others, where respect is gained by the acceptance of differences, tolerance persists, conflicts are resolved through dialog, people's rights are respected and their voices are heard, and everyone is at their highest point of serenity without social tension. Related pages Ceasefire Pacifism Peace makers Peace treaty World peace Peace Basic English 850 words Society

Quebec ( or ; ) is a province in the eastern part Canada located between the Hudson Bay and the Gulf of Saint Lawrence. It is the largest of Canada's ten provinces by size. It also has the second largest number of people, after Ontario. Most of Quebec's inhabitants live along or close to the banks of the Saint Lawrence River. Not many people live in the north part of the province. Unlike the other provinces, most people in Quebec speak French (Canadian French) and French is the only official language. There is a strong French-language culture, which includes French-language newspapers, magazines, movies, television and radio shows. Their culture and language, though, is different from that of France mainly because of Anglicization, having words that come from the larger English-speaking parts of Canada. The government of Quebec has its offices in the capital, Quebec City, which is one of the oldest cities in North America. The city with the most people in the province is Montreal, which is also the second-largest city in Canada. Quebec has many natural resources that are used to create jobs. Quebec also has many companies that create products for information and communication technologies, aerospace, biotechnology, and health industries. It has also developed close relations with the Northeastern United States. Leaving Canada Quebec was part of New France until 1760, then under British control. Quebec became a province in the Canadian Confederation in 1867. Since then, some people in Quebec have wanted to leave Canada. Since Quebec is a mainly French-speaking province, most of the people there feel that it is very different from the rest of Canada, and want to keep it that way. Some feel that for this to happen, Quebec must leave Canada and become its own country. However, the people of Quebec are still divided as to its place in Canada. Quebec held democratic votes in 1980 and 1995 to decide whether to leave Canada. In 1995, the people of Quebec chose to stay in Canada by a 1% margin. History of Quebec Aboriginal people and Inuit groups were the first peoples who lived in what is now Québec. These Aboriginal people lived by hunting, gathering, and fishing. Some of the Aboriginal people, called Iroquoians, planted squash and maize. The Inuit fished and hunted whales and seals for fur and food. Sometimes they warred with each other. Vikings came in longboats from Scandinavia in 1000 AD. Basque whalers and fishermen traded furs with Aboriginal people throughout the 1500s. The first French explorer to reach Quebec was Jacques Cartier. He sailed into the St. Lawrence River in 1534 and established a colony near present-day Quebec City. Samuel de Champlain came from France and traveled into the St. Lawrence River. In 1608, he founded Quebec City as a permanent fur trading outpost. Champlain signed trading and military agreements with the Aboriginal people. Voyageurs, coureurs des bois, and Catholic missionaries used river canoes to explore the interior of the North American continent. After 1627, King Louis XIII of France made a rule that only Roman Catholics could go to live in New France. Jesuit clerics tried to convert New France's Aboriginal people to Catholicism. New France became a Royal Province of France in 1663. The population grew from about 3,000 to 60,000 people between 1666 and 1760. Colonists built farms on the banks of St. Lawrence River. In 1753 France began building a series of forts in the British Ohio Country. Britain asked the French to remove the forts, and the French refused. By 1756, France and Britain were at war. In 1758, the British attacked New France by sea and captured the French fort at Louisbourg. In 1759, British General James Wolfe defeated General Louis-Joseph de Montcalm outside Quebec City. France gave its North American land to Great Britain in 1763. In 1764, New France was renamed the Province of Quebec. In 1774, the British Parliament passed the Quebec Act, giving recognition to French law, Catholic religion, and French language in the colony. The Quebec Act gave the Quebec people their first Charter of rights. The Quebec Act made American colonists angry, so they launched the American Revolution. A 1775 invasion by the American Continental Army was stopped at Quebec City. In 1783, Quebec gave the territory south of the Great Lakes to the new United States of America. In 1867 the Parliament of the United Kingdom passed the British North America Act, which brought most of the provinces together. Quiet Revolution The conservative government of Maurice Duplessis dominated Quebec politics from 1944 to 1960 with the support of the Catholic Church. The Quiet Revolution was a period of social and political change. During the Quiet Revolution, English Canadians lost their control over the Quebec economy, the Roman Catholic Church became less important, and the Quebec government took over the hydro-electric companies. In 1963, a terrorist group that became known as the Front de Libération du Québec (FLQ) began doing bombings, robberies and attacks on government offices. In 1970 the FLQ kidnapped James Cross, the British trade commissioner to Canada. The FLQ also kidnapped and assassinated Pierre Laporte, Minister of Labour and Deputy Premier of Québec. Laporte's body was found in the trunk of Paul Rose's car, on the South Shore of Montreal on October 17 1970. Prime Minister Pierre Trudeau invoked the War Measures Act, and 497 people were arrested. The Quiet Revolution was so named because it was not marked by protests or violence. In 1977, the newly elected Parti Québécois government of René Lévesque introduced the Charter of the French Language. Often known as Bill 101, it defined French as the only official language of Quebec. Government The government is based in the provincial capital, Quebec City. The government is led by a lieutenant-governor (pronounced "lef-") who represents the Crown. As of 2019, he is Michel Doyon. The political leader of the province is the premier. He is François Legault of the Coalition Avenir de Quebec (CAQ), elected in 2018. References Other websites Government of Quebec Discover the Quebec in pictures, photos Bonjour Québec, Quebec government official tourist site Bill 101 CBC Digital Archives – Quebec Elections: 1960–1998 Agora, online encyclopaedia from Quebec An article on the province of Quebec from The Canadian Encyclopedia History Quebec History, online encyclopaedia made by Marianopolis College The 1837–1838 Rebellion in Lower Canada, Images from the McCord Museum's collections Haldimand Collection, documents in relation with Province of Quebec during the American War of Independence (1775–1784) 1867 establishments in Canada Provinces and territories of Canada

Reading is what we do when we understand writing. More fully, it a cognitive process of understanding information represented by printed or written language. It is a way of getting information and insights about something that is written. Reading involves understanding the symbols in that language. It can only be done if one knows the language. Reading and hearing are the two most common ways to get information. Information gained from reading can include entertainment, especially when reading fiction or humor. Proofreading is a kind of reading that is done to find mistakes in a piece of writing. Directed Reading-Thinking Activity is a method which aims to develop better reading. Making predictions/hypothesis about the content, idea, and concepts from the title of the reading material. Sectional reading or processing (chunking) of the material. Checking the reliability and similarity of the read content with the predictions supported by evidence from the text. For better comprehension, to know what and why the text says: review vocabulary, understanding of the main idea, syntax of the sentence, details/facts and sequence of the story, and make inferences about the characters’ attitudes, behaviors or circumstances in the story. Make plausible predictions about what the next section will be about in the reading material. Related pages Literacy Literature Aliteracy Writing Printing References Basic English 850 words Learning

A religion is a set of beliefs that is passionately held by a group of people that is reflected in a world view and in expected beliefs and actions (which are often ritualized). There are many different religions, each with a different set of beliefs. The beliefs are about the world and the people in it, about how they came into being, and what their purpose is. These beliefs according to some religious sects, are often linked to supernatural beings such as God, a number of gods or spirits. They may also be linked to an idea such as a path that the spirit of each person should take towards goodness, truth and duty. This they called spirituality. Each religion has different ideas about these things. Each religion also has a "moral code" which is a set of beliefs about how humans should act. Each religion usually has their own type of "devotions" when people worship or pray. They often have rituals (special things that are always done in the same way) for certain times of the year or certain times of a person's life. Other words that are used for religion are "faith" and "belief system". Altogether, followers of religion can be known as 'believers', or 'the faithful'. Few people follow more than one religion at a time. The largest religions are Christianity, Islam, Hinduism, Buddhism, Taoism, Sikhism, Judaism and Jainism. There are many other religions. People who do not believe in any gods are called atheists. People who say that there is no evidence are called agnostics. Religious beliefs God In many religions, one of the main beliefs is that there is a "deity" (or god) who is a great creator spirit. In many religions, there is just one deity that the people believe in. In other religions, there are many deities who each have different roles in the universe. In many religions, there are other types of spirits. These may include angels, devils and other such things which can be both good and bad. Giving honour to God, the gods or the spirits is an important part of most religions. While this may often be done privately, it is also often done with gatherings of people and rituals. These rituals are often based on old traditions, and may have been done in almost the same way for hundreds, or even thousands of years. Human spirit Another main belief is that humans have a "soul" or spirit which lives on after their body has died. The person's spirit is on a journey through life that continues after death. Most religions believe that what a person does during their lifetime will affect what happens to their spirit in the afterlife. Many religions teach that a good person's spirit can reach a special place of peace and happiness such as Heaven or Nirvana, and that a bad person's spirit can travel to a place of pain and suffering such as Hell. Still other religions believe in reincarnation - that instead of going either to Heaven or Hell, spirits of the dead return to earth in a new body. Morality "Morals" are the way a human behaves to other humans. Most religions make rules about human morals. The rules of how people should act to each other are different in different religions. For some religions, following a "path" of goodness, truth and duty is very important. This is called Tao in China. In the teachings of Judaism, people were told to "love your neighbour as yourself". In the teachings of Jesus, people were told to think of every single person as their "neighbour" and treat them with love. Not every religion teaches people to be kind to all other people. In many religions, it has been common for people to believe that they have to act kindly only to some people and not to others. In some religions, people believed that they could please a god by killing or sacrificing another person. Traditions Teaching A religion is passed on from one person to another through teachings and stories (which are often called "myths") which may be written down like the Bible, or told from memory like the Dreamtime stories of Australian Aboriginal people. In many religions, there are people who take the role of "priest" and spend their lives teaching others about the religion. There are also people who take the role of "pastor" and spend their life caring for other people. A person may be both a priest and a pastor. They are called by different names in different religions. Symbols Symbols are used to remind people of their religious beliefs. They are also used or worn as a sign to other people that the person belongs to a particular religion. A symbol might be something that is drawn or written, it might be a piece of clothing or jewellery, it might be a sign that a person makes with their body, or it might be a building or monument or artwork. Picture symbols for different religions are shown in the box in the introduction to this article. Witness and conversion In many religions, it is thought important that people should show other people that they are following a particular religion. This might be done in a general way by wearing a symbol or a type of clothing. Many people believe that it is important to tell other people about their religion, so that they can believe as well. This is called "witnessing". There are many ways to witness. A young person might simply say to their friends "I do not use drugs or get drunk because of my religion". This is a witness. A person may tell their classmates, workmates and friends about their beliefs. A person might go to other people's houses and talk about their beliefs, or invite the people to join in the rituals of the religion, such as going to church or to a religious festival. A person might have printed material such as books or leaflets that they give to other people to read. A person might travel to a different country to teach, to work in a health service or to help people in some other way. (People who do this are called "missionaries".) These are different ways that people witness to their religion. When a person hears a witness and decides that they will join the religion, this is called a "conversion". Usually a person decides to join a religion because they like what they have read or been told, and they believe that they are hearing the truth. They join the religion because they choose. However, throughout history there have been many times when people have been forced to join a religion by violence and threats. This is still happening today. In most countries of the world, people are free to belong to whatever religion they choose. This is generally thought of as a basic human right. However, there are parts of the world where it is illegal (against the law) to witness to any religion except the one accepted by the government of the country. People who belong to other religions may be threatened, put in jail or murdered. Ritual Rituals are an important part of the tradition of many religions. In many religions, it is the tradition for people to meet for a celebration on one day in every week. There are also major celebrations that may be held only at certain times of the year, for example, on the birthday of a person who is honoured in that religion. Some religions have celebrations for different seasons of the year, or when the sun or moon is in a certain part of the sky. In nearly every religion, the important stages of a person's life have a religious celebration. Birth, naming, reaching an age to think for oneself, reaching adulthood, marriage, childbirth, sickness and death are all celebrated by some religions. Having a celebration or special traditions when a person dies is very common. It is the traditions that are about death that give the earliest evidence of religious beliefs. Scientists have discovered that 120,000 years ago, Neanderthal people started burying their dead. Early Homo sapiens put tools and other things into graves with the bodies, as if they could use them in the afterlife. From 40,000 years ago, many of the objects in graves are small artworks. Scientists believe that these objects were put there for religious reasons. Groups and institutions An institution is one name for an organization. Many religions have organizations that manage the way that people who follow the religion are to act. The organization might employ religious leaders, educate people into the ideas of the religion, manage money, own buildings and make rules. Many religions have sub-groups which are called denominations. In Islam, for example, there is Ahmadiyya, Sunnism, Shi'ism and Sufism. Buildings Most religions have special buildings where people meet. They are often called temples. In Judaism, they are called synagogues. In Christianity, they are called churches. In Islam, they are called mosques. In Buddhism there are pagodas, temples and monasteries. In Hinduism they are called Mandirs. People often try to make their religious building as beautiful as possible. Some religious buildings are great works of architecture. Art and music People often make artworks that are about their religion, or that are used in religious celebration, or are put in a religious building. Religious art comes in all shapes and sizes, from tiny pieces of jewellery to huge statues and paintings. Artworks often give important clues to historians about different ancient religions that are not well understood. Music is often important in religious celebrations. Singing, chanting and playing musical instruments are often part of regular religious gatherings of people. Special music is often used on special occasions. Many famous composers have written religious music. The words of songs that are 3,000 years old are used every day in Christian churches and Jewish synagogues. Related pages Freedom of religion List of religions Philosophy of religion Religious denomination References Further reading Chopra, R.M., "A Study of Religions", 2015, Anuradha Prakashan, New Delhi, Other websites Religion Facts Religion on the BBC website Basic English 850 words

Roman or Romans may refer to: A thing or person of or from the city of Rome, Italy History Ancient Rome (8th century BC – 5th century AD) Roman Kingdom (753 BC to 509 BC) Roman Republic (509 BC to 27 BC) Roman Empire (27 BC to 476/1453 AD) Roman Britain, part of the island of Great Britain controlled by the Roman Empire between AD 43 and about 410 Roman alphabet, the standard alphabet of most of the languages of Western and Central Europe Romanization Roman army Roman calendar Roman law, the legal system of both the Roman Republic and the Roman Empire Roman numerals, numeral system where certain letters are given a numeral value Roman mythology Byzantine Empire (330/476/629 to 1453), the Eastern Roman Empire Romaioi (Ρωμαίοι), Greek-speaking, Orthodox population of the Eastern Roman Empire dating to Late Antiquity Romaioi (Ρωμιοί), Greek-speaking, Orthodox population of the Rum-milet in the Ottoman Empire, or Greek-speaking Orthodox people today Romanae or the Greco-Romans from Aetolia Acarnania that speak Romanesci Holy Roman Empire (c. 900 to 1806), a medieval state in Central Europe Roman, Bulgaria, a town and a municipality in Vratsa Province Romans-sur-Isère, in the Drôme département of France Roman, Romania, a city in Neamţ county Romans, Ain, a town in France Roman, Eure, France Romans, Deux-Sèvres, France Romans d'Isonzo, a town in Italy Roman roads Roman Valley, Nova Scotia Saint Roman, Monaco Christianity Epistle to the Romans, a letter in the New Testament of the Christian Bible The Roman Catholic Church Literature The word for Novel in many European languages. Nouveau roman (lit. "new novel"), a type of French novel of the 1950s Bildungsroman (lit. "formation novel"), German for a coming-of-age story Künstlerroman (lit. "artist's novel"), German for a story of an artist's growth to maturity Romance (heroic literature), a genre of Medieval French literature Ar-Rum, the 30th book in the Qu'ran, is sometimes translated as The Romans Roman à clef, a novel about real life, overlaid with a façade of fiction

Joseph Rudyard Kipling (30 December 1865 – 18 January 1936) was an British author and poet. He was born in Bombay, India. He wrote children's fiction, like Kim, The Jungle Book and Puck of Pook's Hill. He also wrote the well-known poems, If — and Gunga Din, and many short stories set in India. He was awarded the 1907 Nobel Prize in Literature. He spent part of his life living and writing in New England with his American wife but returned to England to live in Sussex. Kipling died of a perforated duodenal ulcer in Fitzrovia, London in 1936 and is buried in Westminster Abbey, London. 1865 births 1936 deaths British children's writers British Nobel Prize winners Disease-related deaths in England Deaths from ulcers English poets People buried in Westminster Abbey People from Bombay

Recreation or fun is a person's time of refreshing his or her body and mind. There are many different forms of recreation which are shaped by individual interests and by environment; a few examples being reading, playing or listening to music, watching movies or TV, gardening, hunting, hobbies, sports, studies, and travel. These activities are just some of a wide variety of recreation activity available in day to day life. Public places such as parks and beaches are very important for many recreational activities. Tourism profession has recognized long ago that many of their clients are specifically attracted by recreational offerings. Related pages Leisure Sport Notes Other websites National Recreation and Park website Leisure Life Hobbies Everyday life

Red is the color that is on the outside edge of the rainbow. It is one of the three primary colors, along with blue and yellow. Red light has a wavelength between 630-740 nanometers. It is sometimes used to mark things that are wrong, important or dangerous. Red is also commonly used as a warning to stop. Meaning of red Red can represent passion, anger, rage or love. In many countries, a red light shows cars when they should stop. In politics, "red" is a symbol of Communism. The "Red Army" can refer to the army of the old Soviet Union, or the People's Republic of China. It is also related to the Red Brigade. Red is the color of heat and blood, so it is associated with energy, war, danger, strength, power, determination, as well as passion, desire and love. Red is an emotionally intense color. It is thought that it tends to raise blood pressure and make people breathe faster. It is very easy to notice, which is why stop signs, stoplights, and fire equipment are usually painted red. In heraldry, red is often used to indicate courage. It is a color found in many national flags. Red brings attention to text and images on the Internet. In advertising, red is often used to cause erotic feelings. Red is widely used to indicate danger. Red is associated with energy, so it may be used to promote energy drinks, games, cars, items related to sports and high physical activity. Comparison of purple, magenta, rose and red Tones of red color comparison chart Light Amour (Pink Mist) (Xona.com color list “Amour Light”) (Hex: #FDF6FA) (RGB: 253, 246, 250) Light Pink Lace ((Xona.com color list "Pink Lace Light") (Hex: #FFF1FB) (RGB: 255, 241, 251) Amour (Red Mist) (Xona.com color list) (Hex: #F9EAF3) (RGB: 249, 234, 243) Bubble Gum (Crayola Magic Scents) (Hex: #FFD3F8) (RGB: 255, 211, 248) Pink Lace (Xona.com color list) (Hex: #FFDDF4) (RGB: 255, 221, 207) Champagne Pink (Pantone TPX 12-1107) (Hex: #F1DDCF) (RGB: 241, 221, 207) Light Cupid (Xona.com color list “Cupid Light”) (Hex: #FDE3F0) (RGB: 253, 227, 240) Light Chantilly (Xona.com color list “Chantilly Light”) (Hex: #FCE5F2) (RGB: 252, 229, 242) Pale Light Pink (Xona.com color list “Pink Light”) (Hex: #FFE4E9) (RGB: 255, 228, 233) Piggy Pink (Crayola) (Hex: #FDDDE6) (RGB: 253, 221, 230) Pale Pink (Hex: #FACCCA) (RGB: 249, 204, 202) Baby Pink (Light Pink) (Hex: #F4C2C2) (RGB: 244, 194, 194) Pink (X11 color) (Tamarisk) (Hex: #FFC0CB) (RGB: 255, 192, 203) Cotton Candy (Crayola) (Hex: #FFB7D5) (RGB: 255, 183, 213) Medium Pink (web color "Light Pink") (Hex: #FFB6C1) (RGB: 255, 182, 193) Cherry Blossom Pink (Hex: #FFB7C5) (RGB: 255, 183, 197) Nadashiko Pink (Hex: #F6ADC6) (RGB: 246, 173, 198) Carnation Pink (Crayola) (Hex: #FFA6C9) (RGB: 246, 166, 201) Tickle Me Pink (Crayola) (Hex: #FC80A5) (RGB: 252, 128, 165) Raspberry Pink (Hex: #E25098) (RGB:226, 80, 155) Pink (Light Red) (web color) (Hex: #FD6C9E) (RGB: 253, 108, 158) Brink Pink (Crayola) (Hex: #FB607F) (RGB: 251, 96, 127) Dark Pink (Hex: #E75480) (RGB: 234, 84, 128) Puce (Hex: #CC8899) (RGB: 204, 136, 153) Pastel Pink (Hex: #DEA5A4) (RGB: 222, 165, 164) Light Salmon Pink (Hex: #FF9999) (RGB: 255, 153, 153) Salmon Pink (Crayola "Salmon") (Hex: #FF91A4) (RGB: 255, 145, 164) Medium Salmon (Hex: #FF8C69) (RGB: 255, 140, 105) Salmon (web color) (Hex: #FA8072) (RGB: 250, 128, 114) Dark Salmon (web color) (Hex: #E9967A) (RGB: 233, 150, 122) Coral Pink (Hex: #F88379) (RGB: 248, 131, 121) Light Coral (web color) (Hex: #F08080) (RGB: 240, 128, 128) Light Carmine Pink (Hex: #E66761) (RGB: 230, 103, 97) Carmine Pink (Hex: #EB4C42) (RGB: 235, 76, 66) <li style = "background-color: #e34234;"> Vermilion (Cinnabar) (Hex: #F34234) (RGB: 227, 66, 52)<li> Coral Red (Hex: #FF4040) (RGB: 255, 64, 64) Carmine Red (Hex: #FF0038) (RGB: 255, 0, 56) <li style = "background-color: #ff3f34;"> Red-Orange (Crayola) (Hex: #FF3F34) (RGB: 255, 63, 52)<li> <li style = "background-color: #ff3f00;"> Electric Vermilion (Mandarin Red) (Hex: #FF3F00) (RGB: 255, 63, 0)<li> <li style = "background-color: #ff4500;"> Orange-Red (web color) (Hex: #FF4500) (RGB: 255, 69, 0)<li> Coquelicot (Red Poppy) (Hex: #FF3800) (RGB: 255, 56, 0) <li style = "background-color: #ff6347;"> Tomato (web color) (Hex: #FF6347) (RGB: 255, 99, 71)<li> Terracotta (Hex: #E2725B) (RGB: 226, 114, 91) Scarlet (Hex: #FF2400) (RGB: 255, 36, 0) Carol Red (Apple Red) (Hex: #EF3038) (RGB: 239, 48, 36) Lust (Hex: #E62020) (RGB: 230, 32, 32) Red (Hex: #FF0000) (RGB: 255, 0, 0) Pigment Red (Hex: #ED1C24) (RGB: 237, 28, 36) Quinacridone Red (Liquitex Heavy Body) (Hex: #E8192F) (RGB: 232, 25, 47) Crimson (web color) (Hex: #DC143C) (RGB: 220, 20, 60) Ruby (Hex: #E0115F) (RGB: 224, 17, 95) Raspberry (Hex: #E00000) (RGB: 224, 0, 0) Razzmatazz (Crayola) (Hex: #E3256B) (RGB: 227, 37, 107) Cerise (Hex: #DE3163) (RGB: 222, 49, 99) Alizarin Crimson (Rose Madder)(Xona.com Color List) (Hex: #E32636) (RGB: 227, 38, 54) Electric Crimson (Hex: #FF003F) (RGB: 255, 0, 63) American Rose (American Beauty) (Hex: #FF033E) (RGB: 255, 3, 62) Radical Red (Crayola) (Bright Amaranth Pink) (Hex: #FF355E) (RGB: 255, 53, 94) Amaranth (Hex: #E52B50) (RGB: 229, 43, 80) Rich Carmine (Chinese Carmine) (Hex: #D70040) (RGB: 215, 0, 64) Utah Crimson (Hex: #D3003F) (RGB: 211, 0, 63) Fire Engine Red (Hex: #CE2029) (RGB: 206, 22, 32) Harvard Crimson (Hex: #C90016) (RGB: 201, 0, 22) Cardinal (Hex: #C41E3A) (RGB: 196, 30, 58) Bright Maroon (Crayola Maroon) (Hex: #C32148) (RGB: 195, 33, 72) Rich Maroon (Maroon (X11)) (web color) (Hex: #B03060) (RGB: 176, 48, 96) Raspberry Rose (Hex: #B3446C) (RGB: 179, 68, 108) Raspberry Glace (Hex: #915F6D) (RGB: 145, 95, 109) Deep Carmine (Hex: #A9203E) (RGB: 169, 32, 62) Crimson Glory (Hex: #BE0032) (RGB: 190, 0, 50) <li style = "background-color: #b80049; color: #ffffff"> Bright Tyrian Purple (Hex: #B80049) (RGB: 184, 0, 73)<li> Medium Carmine (Hex: #AF4035) (RGB: 175, 64, 53) Mahogany (Hex: #C04000) (RGB: 192, 64, 0) Venetian Red (Hex: #C80815) (RGB: 200, 8, 21) Persian Red (Hex: #CC3333) (RGB: 204, 51, 51) Holly (Hex: #CB4154) (RGB: 203, 65, 84) Dark Terra Cotta (Hex: #CC4E3C) (RGB: 204, 78, 92) Chestnut (Indian Red [web color]) (Hex: #CD5C5C) (RGB: 205, 92, 92) Fuzzy Wuzzy Brown (Crayola) (Hex: #C45655) (RGB: 196, 86, 55) Deep Chestnut (Vermont Maple Syrup) (Crayola Chestnut) (Hex: #B94E48) (RGB: 185, 78, 72) Redwood (Pantone TPX 18-1443) (Hex: #A45A52) (RGB: 164, 90, 82) Rose Taupe (Hex: #905D5D) (RGB: 144, 93, 93) Dark Chestnut (Hex: #986960) (RGB: 152, 105, 96) Rust (Hex: #B7410E) (RGB: 183, 65, 14) Cognac (Xona.com Color List) (Hex: #9F381D) (RGB: 159, 56, 29) Burnt Umber (Hex: #8A3324) (RGB: 138, 51, 36) Vivid Burgundy (Hex: #9F1D35) (RGB: 159, 29, 53) Medium Red (Hex: #B10304) (RGB: 177, 3, 4) Carnelian (Hex: #B31B1B) (RGB: 179, 27, 27) Fire Brick (web color) (Hex: #B22222) (RGB: 178, 34, 34) Upsdell Red (Hex: #AE2029) (RGB: 174, 22, 42) Red-Brown (web color Brown) (Hex: #A52A2A) (RGB: 165, 42, 42) Rufous (Hex: #A81C07) (RGB: 168, 28, 7) Tea (Tea Red) (Orange Pekoe Tea) (Hex: #9C0D07) (RGB: 156, 13, 7) Sangria (Hex: #92000A) (RGB: 146, 0, 10) Vivid Auburn (Hex: #922724) (RGB: 147, 39, 36) Burgundy (Hex: #900020) (RGB: 144, 0, 32) Medium Tyrian Purple (Hex: #990024) (RGB: 97, 64, 81) Carmine (Hex: #960018) (RGB: 150, 0, 24) <li style = "background-color: #8b0000; color: #ffffff"> Dark Red (Hex: #8B0000) (RGB: 139, 0, 0)<li> Maroon (web color) (Hex: #800000) (RGB: 128, 0, 0) Deep Red (Crayola Red) (Hex: #850101) (RGB: 133, 1, 1) Barn Red (Hex: #7C0A02) (RGB: 124, 10, 2) Falu Red (Hex: #801818) (RGB: 128, 24, 24) Tuscan Red (Hex: #7B3636) (RGB: 123, 54, 54) Auburn (Hex: #712F26) (RGB: 113, 47, 38) Persian Plum (Xona.com color list) (Prune) (Hex: #701C1C) (RGB: 112, 28, 28) Dark Raspberry (Hex: #E30B5C) (Xona.com Color List Raspberry) (RGB: 227, 11, 92) <li style = "background-color: #66023c; color: #ffffff"> Tyrian Purple (Imperial Purple) (Hex: #66023C) (RGB: 102, 2, 60)<li> Caput Mortuum (Hex: #592720) (RGB: 89, 39, 32) Related pages List of colors Amaranth Burgundy Carmine Cerise Coral Crimson Fuchsia Magenta Maroon Mauve Orange-red Pink Raspberry Redhead Rose Sangria Other websites rouge in easy French Basic English 850 words

For the WWE brand/TV Show, see WWE Raw. Foods are raw when they are not cooked. Most things are good to eat raw, but some can be poisonous. Health There's currently no solid evidence to suggest that raw food is more healthy than cooked food. Germs Raw food can sometimes make people sick because of bacteria which would otherwise be destroyed by cooking. Food and drink Health

Ram can mean: Rama, a Hindu god A male sheep that has not been neutered Random-access memory (abbreviated "RAM") Battering ram, something used to break through walls or doors Hydraulic ram, a type of pump

The Roman Empire was the largest empire of the ancient world. Its capital was Rome, and its empire was based in the Mediterranean. The Empire dates from 27 BC, when Octavian became the Emperor, or Augustus, until it fell in 476 AD, marking the end of the Ancient World and the beginning of the Middle Ages, or Dark Ages. The empire was the third stage of Ancient Rome. Rome was first ruled by Roman kings, then by the Roman Republic, then by an emperor. Augustus Caesar ruled the Roman Republic and Roman Empire so Rome was a republic before it was an empire. Tiberius Caesar ruled Rome as also and appointed Pontius Pilate. Many modern lands were once part of the Roman Empire, for example Britain (not Scotland), Spain, Portugal, France, Italy, Greece, Turkey, Germany, Egypt, Levant, Crimea, Switzerland, and the north coast of Africa. The main language of the Roman Empire was Latin with Greek as an important secondary language, especially in the Eastern provinces of the Empire. The western half of the Roman Empire lasted for about 500 years till the barbarian general Odoacer defeated its final emperor Romulus Augustus. On the other hand, the eastern half, consisting of the Balkans, Anatolia, The Levant and Egypt, continued for about a thousand years more (the Levant and Egypt were lost to the Arabs in the 8th century). The eastern part was called the Byzantine Empire. Its capital was Constantinople, now called Istanbul. Governing the Empire In order to control their large empire, the Romans developed ideas about law and government. They developed the best army in the world at that time, and ruled by force. They had fine engineering, and built roads, cities, and outstanding buildings. The Empire was divided into provinces, each with a governor plus civil and military support. Letters, both official and private, went constantly to and from Rome. Trade was most important for Rome, a city of more than a million people, by far the largest city in the world. They needed, and got, wheat from Egypt, tin from Britannia, grapes from Gaul, and so on. In return, the Romans built provincial capitals into fine cities, protected them from raids by barbarians, and provided education and career opportunities for young people in the provinces, such as jobs in the Roman Army. In principle, emperors had absolute control, and could do as they pleased. In practice, they faced some difficult problems. They had a staff of what we call 'civil servants' and the advice of the Roman Senate. The emperor had to decide what were the most important issues facing the Empire, and what should be done about them. Most of them tried to do two things. One was to do things to improve the life of Romans in peacetime. The other was to fight and defeat Rome's enemies. A wealthy empire always has enemies. With kings and emperors, a big problem is the order of succession. Kings were sometimes followed by their eldest son, if he was capable of ruling. For Roman emperors, more often it would be an adopted son. It worked like this. The emperor would notice an outstanding young man from one of the best families. He would adopt him as his son. Before he died he would make clear whom he thought should succeed him, by making him a Roman consul, or by stating in his will that the younger man should succeed him. Sometimes this worked; sometimes it did not. Every now and then there would be a civil war between claimants to the throne. An adopted son or two gave the emperor more choices. Some emperors had no son; some had sons who did not survive. Later on, emperors grew so weak that the Roman army would just pick one of their generals to be the next emperor. This often led to civil war. The life stories of the emperors can be found in List of Roman emperors. The Romans fought many wars against other countries, and against barbarians several times. They enjoyed watching violent sports. They enjoyed watching chariots races, and fights between gladiators (men using weapons). Unlike in modern sports, the fighters were often killed in fights. Romans enjoyed these shows in the Colosseum. The Romans had great civil engineering. They built many large public buildings and villas, aqueducts to carry water, stone bridges and roads. Some of these things can still be seen today. Many famous writers were Romans, including Cicero and Virgil. The New Testament of the Bible tells about the Romans in the life of Jesus Christ. During Jesus' life, the Romans, who were pagans, ruled his country. Later, several emperors tried to destroy Christianity but they did not succeed. By 312 the emperor Galerius allowed people freedom to follow Christianity, and the next year, a general, Constantine, became emperor and converted to Christianity. The city of Rome was taken over several times by barbarians, notably in 410 when the Goths sacked the city (looting). The last Western Roman emperor, Romulus Augustus, resigned in 476 . The Roman Empire would last another 1,000 years as the Byzantine Empire in the east. The main coin of the Roman Empire was the silver denarius. Later denarii were smaller. Various reasons have been given for the fall of Rome. Edward Gibbon wrote The Decline and Fall of the Roman Empire in which he investigated various ideas. Chief among them was (in his opinion) was the effect of Christianity on the ability of the Empire to defend itself militarily. Other historians blame the unstable system of leadership. In a 50-year period, only 2 out of 22 emperors died a natural death. Most of the emperors were assassinated. References Other websites An old map of the Roman Empire in 400 AD BBC, Romans for Children , website on ancient Rome for children at the level of primary school Rome Unleashed, interactive educational website on ancient Rome for students

A regime is the leader and other people who run a government of a sovereign state. There are many kinds of regimes. They can achieve power in many ways. Depending on the time and place and local civics like the electoral system, they can lose power in many ways too. The most common way for a regime to lose power was a coup, invasion or revolution until the 20th century. After that it became very dangerous and difficult to use these methods. Peaceful regime change is usually by an election - this method is now used by more than half the people on the Earth. It is called representative democracy. Such regimes are often called administrations to make it clear they are not dictators, and since the executive branch does not have all the power itself - it may share it with a legislative branch. Also the judicial branch is separate. The courts are not usually considered part of the regime. However, some things are the same no matter how the regime achieved power: The regime needs help among people outside the regime and government to stay in power - these may be in the military or a political party. Military and police obey the regime's orders, and can kill people. If they would not do so, then, it would be possible to change regimes by force. Trade and tax is set by the regime, which can take money away. The regime speaks for the whole country when dealing with other countries. When many regimes negotiate at the United Nations or World Trade Organization, it does not matter at all how each regime got its power. It matters only that they can agree and make everyone in their country do as the agreement says. When someone wants a regime to change in another country, they usually are not able to do this by any means other than violence or interfering in its election. This is common if a regime is threatened by another regime. Forms of government

A river is a stream of water that flows through a channel in the surface of the ground. The passage where the river flows is called the river bed and the earth on each side is called a river bank. A river begins on high ground or in hills or mountains and flows down from the high ground to the lower ground, because of gravity. A river begins as a small stream, and gets bigger the farther it flows. River parts The beginning of a river The start of a river is called the source or head water. The part of the river that is near the source is called a 'young' river. A young river is often in a V-shaped river bed, and flows quickly downhill over stones, and around big rocks. Young rivers often have lots of small waterfalls and rapids. As the rivers travel downhill they begin to erode the ground taking small bits of soft rock and soil. The source of a river may be a spring, often on a hill, mountain, glacier, or another high place. A spring is water that flows out from under the ground. The source of a river may be a lake where lots of water from small streams gathers when it rains or snows. A river may begin in mountains where there is snow. The melting snow runs together to form a small stream that runs down the mountain. As more little streams run in, the main stream gets bigger, until it forms a river. Some rivers flow from hills where there is no snow, but lots of rain. Some rivers only flow after there has been rain near the head water. The middle part of a river The middle part of a river is called a mature river. A mature river makes a riverbed that is U-shaped. It might be very deep and run fast. It sweeps over small rocks and boulders, and makes big turns around hills and mountains. It is much wider than a young river, but not as wide as an old river. To cross over a mature river, people use bridges. Many cities and towns are built on the banks of mature rivers. Many farms that keep animals such as dairy cows, horses and sheep are along mature rivers because the animals can drink from the river every day. The last part of a river A river usually ends by flowing into an ocean, a lake or a bigger river. The place where the river flows out into a bigger body of water is called the 'mouth' of the river. As a river flows towards its mouth, the countryside around the river often changes from hilly to flat. As it flows over the flat land the river becomes wider and slower. A wide slow river is called an 'old river'. An old river often floods across the land after there is lots of rain at the headwaters. An old river slowly builds up its banks on either side; the high banks are called levees. An old river often meanders (twists and turns), and sometimes, after a flood, it leaves lakes behind which are called ox-bows or billabongs. Old rivers are the most useful type of river for growing crops. Corn, rice, fruit, cotton, hay, tobacco and sugar are some of the crops that are grown near old rivers. The shape of the mouth depends on the conditions of the sea where it flows. If there is a strong tide where the river meets the sea, the river forms an estuary. An estuary is a wide, funnel-like mouth of the river. The fresh water of the river mixes slowly with the salt water, becoming brackish water – somewhat salty water. Many kinds of fish, clams, molluscs and other sealife live at estuaries. Many of the world's largest cities and harbours are at estuaries. Where a river flows out to the sea, it sometimes flows very slowly through sandy or muddy land, making lots of little islands as it flows. The main stream of the river gets broken into many parts that spread out into a triangle shape like the Greek letter delta. When this happens, it is called the delta of the river. Deltas are often places that are not good for towns or farms but are very good for birds and other wildlife and fishing. Deltas are often made into wildlife reserves. Not all rivers have deltas. There are deltas on the Nile River, the Amazon River, the Mekong River, the Mississippi River and the Danube River. Underground rivers Some rivers flow underground through caves. Underground rivers form in places where there are lots of cracks in the rocks above, so that in rainy weather, the water runs downs and collects in small underground streams. Sometimes the underground water trickles or gushes out of the ground to form a small spring of water. In other places, where there are caves, the small underground streams run together to form a river. The river can sometimes run through deep wide underground caverns. While many underground rivers flow gently, some underground rivers flow fast and have rapids, particularly after heavy rain. Many underground rivers flow out through a cave mouth to become an ordinary river. Using rivers The water in rivers is "fresh water" that has come from rain, snow and from underground streams. It can usually be drunk safely by people unless it is too dirty because of mud or human pollution. People and animals need fresh water to drink, so they often live by the side of a river. Rivers give water for drinking, bathing and washing clothes. Rivers give water for cattle and other animals to drink and for people to grow plants. Rivers give products that are useful to people such as fish for food, clay for bricks and reeds to make the roofs of houses. Rivers can be used for transporting people, crops and other goods by boat. Rivers can be used to give power to turn machinery such as water mills. Rivers give water for factories that make cloth, steel and many other products. Rivers sometimes have dams to hold the water for people to drink, or to make electricity. Rivers can be used for leisure and sports such as swimming, boating, fishing and just walking by the river. Rivers often have beautiful scenery. Many painters, story-tellers and poets have painted or written about rivers. Rivers are sometimes turned into canals. Water for living Water for industry Water for fun Rivers in art, literature and music Mark Twain, The Adventures of Tom Sawyer, (novel) Kenneth Grahame, The Wind in the Willows, (novel) Rivers in photography Important rivers Amazon River in South America is a very wide tropical river flowing through the Amazon Jungle and into the Atlantic Ocean through a large delta. Many types of fish live in it. It is the largest river in the world. Nile River in Africa. For thousands of years this river has provided the people of Egypt with water to help their food grow. Cairo, the biggest city in Egypt and Africa, is built near the Nile's delta on the Mediterranean Sea. It is the longest river in the world. Mississippi River in the United States. Many crops are grown along the sides of the Mississippi. It was also used for transport. The Mississippi flows through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. Yangtze River, a very large river in China, the third longest in the world, and the longest in Asia Rhine River Rivers Tigris and Euphrates Ganges River Mekong River River Danube Volga River St. Lawrence River Murray River in Australia, 1609 miles in length. Congo River Niger River River Thames Tiber River River terminology A meander is a bend or curve in a river. The mouth of a river is where the river enters the sea, ocean or lake. An oxbow lake is located at the side of a river and is curved like a "meander" A braided river is a usually slow-moving river which splits up and joins together repeatedly. Other types of rivers A submarine river is a stream of water that flows along under the surface of an ocean. One of them, named the Cromwell current, was found in 1952. ("Sub marine" comes from Latin and means "under sea".) A subterranean river is a river which flows under the surface of the earth. One of them was found in August 1958 under the Nile River. (The term "sub terranean" also comes from Latin and means "under ground".) Related pages Water Valley Lake Flood Drought Erosion References Basic English 850 words Biomes

A right angle is an angle with a measurement of 90 degrees. When two lines cross each other so that all the angles have the same size, the result is four right angles. The top of the letter T is at right angles to the vertical line. Walls of buildings are usually at right angles to the floor. Two things that are at right angles are called "perpendicular" or "orthogonal". This is expressed using the symbol (such as in ). Planes (flat surfaces) can also meet at right angles. In a building, a wall and a floor are said to be perpendicular to each other, and they have a right angle. It also can be called a square angle. Related pages Acute angle Obtuse angle Parallel (geometry) References Angles

A reward is getting something good for doing a given task. It needs someone who has the power to give the good thing. It is the opposite of punishment. Ideas like risk and reward, reward and punishment are based on the idea that people do things, or avoid doing things, to get rewards. In psychology there is another idea that this is not true. This other idea says that training (conditioning) and emotions (affective factors) are much more important than the rewards or punishments given by others. In trying to catch criminals and other bad people, the government often offers money to people. This money is given to people who may capture the criminal, or give information that helps the police catch them. For example, after the Eureka Stockade rebellion in Ballarat, Victoria in 1854, the government offered a big reward of 400 pounds for the capture of the people who had started it. In 2001, the US government offered a big reward of 2.5 million dollars for help in capturing the person who had sent anthrax in letters to a newspaper journalist and 2 senators. Anthrax is a disease which can kill people. Related pages Carrot and Stick References Basic English 850 words

A ranch is a large farm for raising cows, horses, sheep or other livestock. The word ranch is from the Spanish word "rancho". It is used in American and Canadian English. A ranch may be on private or public land. The desert areas of the western United States have many ranches, because there is much land that is not very good for crops. There are also many in desert areas of Australia, where they are called stations. Someone who takes care of the livestock may be called a stockman or cowboy. Related pages Agriculture

A sport utility vehicle (SUV) is a type of vehicle. It is built as a rugged vehicle for cargo and passenger carrying. Originally SUVs were not designed to be fuel efficient but modern designs are getting better fuel mileage. In 2014 US sales of SUVs were over five million vehicles. Appearance The typical SUV is a two-box design. Unlike a pickup truck (US term) that has an open cargo box the SUV has an enclosed cargo/passenger compartment. It has upright seating for five to seven passengers. It has an open interior with no trunk. It is often built on a pickup truck chassis for towing capacity, and usually has four wheel drive. Only about 15% of SUV owners ever go off-road. According to Jeep Wrangler brand manager Kevin Metz, 60% of Jeep Wrangler owners go off-road while around 80% of Rubicon owners do. A similar class of vehicle is the CUV crossover, a common UK term. That is built on a car chassis. Often it uses a Unibody chassis instead of the heavier body-on-frame design of SUVs. Crossover vehicles often have all-wheel-drive instead of four-wheel drive. Crossovers are usually lighter than SUVs and get better fuel mileage. In general, when referring to an SUV, many include crossovers. However it is incorrect to refer to an SUV on a truck frame as a crossover. History Early SUVs were built like light commercial and light wheeled military utility vehicles. Famous examples were the World War Jeep (US), and the Land Rover (UK). The term "sport utility vehicle" came into popular use in the late 1980s. Until then, they were marketed as station wagons. An early example of marketing a civilian off-roader as a "sports utility" is the two-door pickup version of the 1966 Ford Bronco. In 1974 Jeep used the term "sport(s) utility vehicle" exactly in their brochures for the 1st generation Jeep Cherokee. Off-roading sports Many kinds of off-roading in the USA are centered around SUVs. Rockcrawling is a popular off-road sport. Vehicles used for rock crawling are usually modified with different tires, suspension and gear ratios. Rock crawling takes time to learn and can be very expensive. Most rock crawlers have full-time jobs and many get sponsors to help with the costs. The object is to get the vehicle across difficult to near-impossible rocks and terrain without completely destroying the vehicle. The Camel Trophy competition (1981–2000) was an annual 4x4 competition. The first Camel trophy was held on the Trans-Amazonian Highway, a road across Brazil. Over the next eight years, the expeditions crossed Sumatra, Papua New Guinea, Zaire, Brazil, Borneo, Australia, Madagascar and Sulawesi before returning to the Amazon. After the first year the endurance event came to be dominated by specially equipped Land Rover vehicles. The Camel Trophy Owners Club is a group of people who collect ex-Camel Trophy vehicles. Jeep Jamborees have been held since 1953. Jeep Jamborees are off-road excursions that travel historic and scenic trails across the US. In 2013 alone there were 32 events in various locations. All models of Jeep enter the events and drivers range from first time off-roaders to seasoned veterans. Easter Jeep Safari is an annual event held at Moab, Utah. It has been held every year since 1967. It runs for nine days ending on Easter Sunday and can have up to 1,000 vehicles of all kinds; not just Jeeps. It uses up to 40 trails in the Moab area. Trails are rated from easy to difficult. King of the Hammers is an a one-day 200+ mile endurance off-road race. It combines desert racing and rock crawling. This race is held in February on Means Dry Lake at Johnson Valley, California USA. 2015 will be the 9th annual King of the Hammers event. The vehicles are extremely modified and for off-road use only. Popularity There are many reasons why SUVs have become popular. One reason is the comfort of their large cabins. Many models can carry almost as much as a minivan. Another reason is the driver sits higher than other cars, giving better all-round vision. SUVs with truck frames are heavier (sometimes much heavier) than standard cars. Their size gives them an image of safety. Men aren't the only targets of SUV and CUV ads. For example, some ads for the Subaru Forester are deliberately aimed at women buyers. Roughly 35 to 40 percent of SUV buyers are women. Ads commonly show SUVs driving across boulders or perched on a mountain peak. Advertisers know that one important reason many people buy SUVs is image. Practicality for larger families is a consideration. Not only can the vehicle take a family of five or six, plus luggage, but also the family dog (who often has a special compartment at the back). On the other hand, the vehicle doesn't fit standard parking spaces. That can be quite a problem in, for example, the UK. The alternative, when groups of more than four travel, is to take more than one standard size car. Other names In Australia and Europe SUVs are often called 4 wheel drives (4X4) or 4WDs. References

Substance is the material, or matter, of which something is made. Substances are physical things that can be seen, touched, or measured. They are made up of one or more elemental parts. Iron, aluminium, water and air are examples of substances. Problems of definition The main problem of a clear definition of what the substance is that if, for example, to consider not just the universe (cosmos), being and non-being, and in general all, the question arises, what is the constant basic principle (attribute) is the basis of the substance, which generally consists of all (that is, matter, mind, senses, space, soul, and so on). History of the concept The Latin word substantia - a translation of the Greek word for the essence (ousia), and in Latin to describe the essence of using the word essentia. In ancient philosophy substance is treated as a substrate, the first principle of all things (for example, "water" of Thales, the "fire" of Heraclitus). In modern times, the concept of substance is treated and spread widely. The first view is connected with an ontological understanding of substance as ultimate bases being (Francis Bacon, Benedict Spinoza, Gottfried Wilhelm Leibniz). Central category of metaphysics in philosophy substance is identified as with God and with nature and determined as the cause of itself (Latin, causa sui). The main characteristics (attributes) of a substance from Benedict Spinoza are thinking and stretch. By analogy with the philosophy of Benedict Spinoza substance considered in the light of the concept of René Descartes and Leibniz. The first substance is a unity of subject and object, and the second - the same atoms are simple beings who lose their stretch, but receive attribute aspirations (French, appetition) and multiplicity. Thanks Leibniz substance begins to associate with matter. The second point of view on the substance - an epistemological understanding of the concept, its capabilities and the need for scientific knowledge (John Locke, David Hume). Immanuel Kant believed that the law under which any change in the substance of events and the number of stored it in nature remains the same, can be attributed to the "analogies of experience." Georg Wilhelm Friedrich Hegel defined substance as the integrity of changing, transient side of things, as a "major step in the development of the will." For Arthur Schopenhauer substance - matter for David Hume - a fiction, the coexistence properties. Related articles Chemical substance Basic English 850 words Physics

A symbol is a drawing, shape, or object that represents an idea, object, or amount of something. The most common symbols are letters, which are symbols of words and sounds. A symbol can be an actual object (such as the cross, a symbol of Christianity or a scepter, a symbol of royalty and power), or a certain color or pattern. Symbols are used often in poetry and other types of literature, sometimes as metaphors or similes. A national emblem is a symbol for a certain country. List of common symbols There are thousands of symbols that are recognized by most people all over the world, and many more that are limited to certain regions, religions, sciences, etc.. Some of the best known ones are listed below. Alpenhorn -> Switzerland Asiatic Lion -> India Balance (scale) -> justice Bat -> vampire (western), luck (Chinese) Bear -> the U.S. state of California Beaver -> Canada Boomerang -> Australia Caduceus -> Medical profession Cadillac -> top of the line (in USA only) Cedar tree-> Lebanon Cheetah -> speed Cherry Blossom -> Japan Chukar -> Pakistan Compass rose -> navigation Cowboys and Indians -> the old Western USA Crucifix -> Christianity Cupid, heart -> love Cedrus deodara -> Pakistan Donkey -> United States Democratic Party Dove -> Peace Dragon -> China / Wales Eagle -> USA Elephant -> United States Republican Party Elephant -> Thailand Fatima Jinnah -> Pakistan Flags -> the associated countries Fleur-de-lis -> scouts, the Canadian city of Quebec Geneva cross -> ambulance, neutrality, humanitarian Great Wall of China -> China Hammer and sickle -> U.S.S.R., Communism Hat and wand -> magic Horseshoe -> good luck Igloo -> North Pole James Dean -> rebellion Jasmine -> Pakistan Kangaroo -> Australia Kiwi -> New Zealand Liberty Bell -> USA Lightbulb -> idea Lightning bolt -> electricity, speed Lion -> England Llama -> South America Lotus -> Hinduism and Buddhism Mango -> Pakistan Markhor -> Pakistan Maple leaf -> Canada Mortar and pestle -> Pharmacy Mount Fuji -> Japan Mount Rushmore -> USA Muhammad Ali Jinnah -> Pakistan Owl -> wisdom/education (western worlds), may mean evil in other place. Panda -> China Peace symbol -> hippies Penguin -> South Pole, Linux Pine tree and crane -> long life (Chinese) Plum flower -> China Pocket protector -> nerds Poinsettia -> Christmas Polar bear -> North Pole Rainbow -> Peace, Disarmament, Sustainability Rainbow flag -> LGBTQ people Rose -> England Rams -> Guangzhou Rolls Royce -> luxury, top of the line Royal Bengal Tiger -> Bangladesh St. Bernard (dog) -> rescue Shamrock -> Ireland, Trinity Shogun -> Japan Skull and crossbones -> poison, danger Star and crescent -> Islam Star of David -> Judaism Statue of Liberty -> USA Swastika -> Hinduism, Buddhism, Nazism Teen Talwar -> Pakistan Thistle -> Scotland Tulips -> Netherlands Turkey -> Thanksgiving holiday Uncle Sam -> USA Unicorn -> good luck Volvo cars -> bad/elderly drivers (Australia), prestige (European Union), Sweden Water Lilly -> Bangladesh White Flag -> France Windmills -> Netherlands Yin yang symbol -> Daoism

September (Sep.) is the ninth month of the year in the Gregorian calendar, coming between August and October. It has 30 days. Its name comes from the Latin word sept for "seven" (it was the seventh month of the year, before January and February were added to the beginning of the year.) September always begins on the same day of the week as December, but never ends on the same day of the week as any other month. The Month In the old Roman calendar, September was the seventh month, which is where it got its name ("Septem" means "seventh"). The ninth month at the time was November ("Novem" means "ninth"). With Julius Caesar's calendar reform, September became the ninth month, with 30 days. September comes after August and before October. September begins on the same day of week as December every year, as each other's first days are 13 weeks (91 days) apart. No other month in any year ends on the same day of the week as September: this month and May are the only two months with this property. In common years, September starts on the same day of the week as April and July of the previous year, and in leap years, October of the previous year. In common years, September finishes on the same day of the week as April and December of the previous year, and in leap years, July of the previous year. In leap years and years immediately after that, September starts on the same day of the week as January of the previous year. In years immediately before common years, September starts on the same day of the week as June of the following year, and in years immediately before leap years, March and November of the following year. In years immediately before common years, September finishes on the same day of the week as March and June of the following year, and in years immediately before leap years, August and November of the following year. September is one of two months to have an equinox (the other is March, its seasonal equivalent in both hemispheres), where both day and night are roughly of equal length, occurring either on the 22nd or 23rd, halfway between the June and December solstices. In the Northern Hemisphere, Autumn (Fall) begins in this month, while in the Southern Hemisphere, this is the beginning of Spring. For meteorologists, the people who study the weather, these seasons begin on September 1 in those hemispheres. In most Northern Hemisphere countries, school starts in this month, following the summer holidays. In Ancient Greece, September was called Boedromion. The Anglo-Saxons called it Gerstmonath, meaning "Barley month", referring to the harvest. In other countries, it is referred to as Autumn Month, such as in Finland (Syyskuu) and German-speaking parts of Switzerland (Herbstmonat). Ethiopian New Year occurs in September. Jewish New Year also often occurs in this month. Events and Occurrences Fixed Events September 1 Independence Day (Uzbekistan) September 1 Armed Struggle for Independence (Eritrea) September 1 Constitution Day (Slovakia) September 2 Independence Day (Vietnam) September 3 National Day of San Marino September 3 Independence Day (Qatar) September 3 Flag Day (Australia) September 3 Levy Mwanawasa Day (Zambia) September 3 Merchant Navy Day (United Kingdom) September 5 Teacher's Day (India) September 6 Independence Day (Swaziland) September 6 Unification Day (Bulgaria) September 7 Independence Day (Brazil) September 7 National Threatened Species Day (Australia) September 7 Victory Day (Mozambique) September 8 National Day of Andorra September 8 Independence Day (Republic of Macedonia) September 8 Nativity of the Blessed Virgin (feast day in Christianity) September 9 Admission Day (California) September 9 National Day of North Korea September 9 Independence Day (Tajikistan) September 11 National Day of Catalonia September 11 Patriot Day (United States) September 11/12 Ethiopian New Year September 12 National Day of Cape Verde September 13 World Chocolate Day September 14 Exaltation of the Holy Cross (Roman Catholicism) September 15 Battle of Britain Day (United Kingdom) September 15 National Day of Costa Rica, El Salvador, Guatemala, Honduras and Nicaragua September 16 Independence Day (Mexico) September 16 Independence Day (Papua New Guinea) September 16 Malaysia Day September 17 Constitution Day (United States) September 18 Independence Day (Chile) September 19 Armed Forces Day (Chile) September 19 Independence Day (Saint Kitts and Nevis) September 19 International Talk Like a Pirate Day September 21 Independence Day (Malta) September 21 Independence Day (Belize) September 21 World Freedom Day/International Peace Day September 21 World Alzheimer's Day, raising awareness of Alzheimer's disease. September 22 Independence Day (Bulgaria) September 22 Independence Day (Mali) September 23 Equinox, Autumn (Fall) in the North, Spring in the South, can occur on September 22. September 23 National Day of Saudi Arabia September 24 National Day of Guinea-Bissau September 24 Heritage Day (South Africa) September 25 Revolution Day (Mozambique) September 26 European Day of Languages September 27 End of Independence War Day (Mexico) September 27 Holiday for the French-speaking community in Belgium September 28 World Heart Day September 28 World Rabies Day September 28 Ask a Stupid Question Day (United States) September 29 Inventors' Day (Argentina), honouring Laszlo Biro September 29 Christian feast day of Michaelmas, honouring St. Michael the Archangel September 29 Christian feast day of the three Archangels, honouring St. Michael, St. Gabriel and St. Raphael. September 29 International Coffee Day September 29 Victory of Boquerón Day (Paraguay) September 30 Independence Day (Botswana) Moveable and Monthlong Events The Summer Olympics sometimes occur in September, though mostly in July or August The Summer Paralympics are often held in September Yom Kippur, in the Jewish calendar, occurs in September or October. Labor Day (US and Canada), first Monday in September Prinsjesdag (Netherlands), third Tuesday in September Munich Oktoberfest runs in late September and the beginning of October. Start of school in most Northern Hemisphere countries German American Heritage Month and Hispanic Heritage Month (United States), run from September 15 to October 15. Marathons in September: Berlin, Germany Kathmandu, Nepal Mexico City, Mexico Oslo, Norway Sydney, Australia Tallinn, Estonia Vilnius, Lithuania Selection of Historical Events September 1 1715: The reign of Louis XIV of France ends with his death after 72 years on the throne. September 1 1914: Martha, the last Passenger Pigeon, dies, making her species extinct. September 1 1939: Nazi Germany invades Poland, starting World War II. September 1 1969: Muammar al-Gaddafi takes power in Libya, in a coup. September 1 1983: Korean Air Flight KAL-007 is shot down by a Soviet jet fighter, near Sakhalin Island, killing all 269 on board. September 1 1991: Uzbekistan becomes independent from the Soviet Union. September 2 1838: Liliuokalani, the last Hawaiian monarch, is born. September 2 1945: Japan signs the final surrender at the end of World War II. September 2 1945: Vietnam becomes independent, with Ho Chi Minh as leader. September 3 301: San Marino is founded. September 3 1939: The United Kingdom and France declare war on Germany, following its invasion of Poland. September 3 1950: Giuseppe Farina becomes the first Formula One racing champion. September 3 1967: Road traffic in Sweden is moved from the left to the right. September 3 1971: Qatar becomes independent. September 5 1972: Several members of the Israeli Olympic team are kidnapped at the 1972 Summer Olympics in Munich. They are killed the next day. September 6 1901: US President William McKinley is shot by Leon Czolgosz, dying over a week later. September 6 1968: Swaziland becomes independent. September 6 1997: The funeral of Diana, Princess of Wales takes place in London. September 7 1533: Queen Elizabeth I of England is born. September 7 1822: Brazil declares independence from Portugal September 7 1940: The World War II Battle of Britain begins. September 7 2011: All members of the Russian ice hockey team Lokomotiv Yaroslavl are killed in a plane crash. September 8 1943: US General Dwight D. Eisenhower announces the allied armistice with Italy during World War II. September 8 1991: The Republic of Macedonia declares independence from Yugoslavia. September 9 1850: California becomes the 31st State of the US. September 9 1991: Tajikistan becomes independent from the Soviet Union. September 10 1898: Elisabeth of Bavaria, Empress of Austria is stabbed to death by Italian anarchist Luigi Lucheni at Lake Geneva, Switzerland. September 10 1974: Guinea-Bissau officially becomes independent. September 10 2008: Scientists at CERN switch the Large Hadron Collider on for the first time. September 11 1973: Augusto Pinochet takes power in a military coup in Chile. President Salvador Allende dies during the coup. September 11 1997: Voters in Scotland approve the creation of a new Scottish Parliament. September 11 2001: The September 11 attacks occur, as Islamist terrorists crash airplanes into the World Trade Center in New York City and the Pentagon. September 12 1977: Anti-Apartheid activist Steve Biko dies in police custody. September 13 1759: Battle of the Plains of Abraham: British forces defeat French forces near Quebec City in the Seven Years' War. September 14 1752: Great Britain switches from the Julian calendar to the Gregorian calendar. September 14 1982: Grace Kelly dies after a car crash the previous day. September 15 1821: Costa Rica, El Salvador, Guatemala, Honduras and Nicaragua declare independence from Spain. September 16 1810: Mexico declares independence from Spain. September 16 1975: Papua New Guinea becomes independent from Australia. September 17 1787: The United States Constitution is signed in Philadelphia, Pennsylvania. September 17 2011: The Occupy Wall Street movement begins in New York City. September 18 1810: Chile declares independence. September 18 1970: Musician Jimi Hendrix dies in London, aged 27. September 19 1983: Saint Kitts and Nevis becomes independent. September 19 1985: Southern and Central Mexico are struck by a strong earthquake. Mexico City is among the places affected. September 21 1964: Malta gains independence from the UK. September 21 1981: Belize gains independence from the UK. September 21 1989: Hurricane Hugo slams South Carolina. September 21 1991: Armenia regains its independence from the Soviet Union. September 22 1908: Bulgarian independence is recognised. September 22 1960: Mali becomes independent. September 23 63 BC: Roman Emperor Augustus Caesar is born. September 23 1932: The Kingdom of Saudi Arabia is formed. September 23 2009: A major dust storm affects southeastern Australia, including Sydney. September 24 1853: France takes control of New Caledonia. September 24 1973: Guinea-Bissau declares independence from Portugal. September 26 1907: New Zealand and Newfoundland are given Dominion status within the British Empire. September 27 1821: Mexico gains independence from Spain. September 27 1905: The equation E=mc squared is introduced. September 28 1978: Pope John Paul I dies just 33 days after being elected. September 28 1994: The car and passenger ferry Estonia sinks during stormy weather in the Baltic Sea. September 29 1829: London's Metropolitan Police Force is founded. September 29 1990: Washington National Cathedral is completed. September 29 2009: An earthquake and tsunamis off Samoa, American Samoa and Tonga kill 189 people. September 30 1938: The Munich Pact is signed. September 30 1955: American film star James Dean dies aged 24 in a car crash. September 30 1966: Bechuanaland becomes independent from the UK and changes its name to Botswana. September 30 2009: A strong earthquake off western Sumatra kills over 1,000 people. Symbols and Trivia September is one of the two months that never ends on the same day of the week as any other months within any calendar year. (May is the other) The birth stone for September is the sapphire, symbolising clear thinking. The birth flowers for the month are the forget-me-not, morning glory and aster. The Zodiac signs for September are Virgo (August 22 September 21) and Libra (September 22 October 21). If the months of the year were arranged in alphabetical order in the English language, September would come last. Also in the English language, September has the longest name of all the months of the year, with nine letters. Coincidentally, it is also the ninth month. September is the only month of the year in the English language to have as many letters in its name as its numeric calendar position. September is the first of four months in-a-row to have a name ending in "ber". (October, November and December are the other three) September 1 is the only day in September during a common year to start within the middle third of the calendar year. It is the least common month for birthdays among US Presidents, with one, William Howard Taft (September 15). Among Prime Ministers of Australia, September is the most common month for birthdays, with seven.

Sound can also mean a body of water, like a bay or channel. Sound is caused by sound waves. It can be heard when goes through a medium to the ear. All sounds are made by vibrations of molecules. For example, when a person hits a drum or a cymbal the object vibrates. These vibrations make air molecules move. Sound waves move away from where they came from. When the vibrating air molecules reach our ears, the eardrum vibrates, too. The bones of the ear vibrate in way the object that started the sound wave vibrated. There are three different mediums. They are solids, liquids and gas. Sound travels the fastest through solids because the particles in a solid are closer together than they are in gas and liquid. These vibrations let you hear different things. Even music is vibrations. Irregular vibrations are noise. People can make very complex sounds. We use them for speech. Sound waves are longitudinal waves with two parts: compression and rarefaction. Compression is the part of the sound waves where the molecules of air are pushed (compressed) together. Rarefaction is the part of the waves where the molecules are far away from each other. Sound waves are a sequence of compression and rarefaction. Vacuum Since sound is a vibration of a medium, it cannot go through a vacuum. A vacuum is a place where there is no medium, for example in outer space. The word comes from the Latin adjective vacuus for "vacant" or "void". Speed of sound Sound waves can travel through solids, liquids, and gases. The thicker the medium, the faster it goes, but they cannot travel through a vacuum (a place with nothing in it). This is why astronauts cannot talk to each other in space: they need a radio to hear each other. Sound can travel through water faster than through air; and even faster in solids like stone, iron, and steel. At room temperature and normal atmospheric pressure, sound travels at 344 m/s (1134 ft/s), 761 miles per hour). Because the temperature and pressure change with altitude in the atmosphere, speed will vary as well. Pitch and Intensity Pitch is the highness or lowness of sound. Pitch is how humans hear different frequencies. Frequency is determined by the number of vibrations per second. The highest key on a piano, for instance, vibrates 4,000 times per second. It has a frequency of 4000 hertz (Hz), or 4 kilohertz (kHz). Lower keys have lower frequencies. A note an octave higher than another note has twice the frequency of that note. The intensity of a sound is how much sound energy goes through a square meter in one second. Sound waves with higher amplitude (bigger vibration) have higher intensity. The intensity of a sound is higher closer to the sound source. Farther away, it's less intense. The inverse-square law shows how sound intensity becomes smaller, farther from the source. "Inverse square" says that when distance gets multiplied by a number, sound intensity gets divided by that number squared (the number times itself). Thus, twice the distance means a quarter the intensity. Sound intensities can be very different. They can range from 0.000000000001, which are barely heard, to 1 W/m2 (painfully loud). The decibel scale makes sound intensity numbers easier to work with. A 0.000000000001 W/m2 intensity is 0 dB (decibels). It is an exponential scale, so when the decibel number increases by 10, the intensity is ten times as much. So, a 1 W/m2 intensity is 120 dB. Loudness is how people sense the intensity of sound. Loudness depends on sound intensity, sound frequency, and the person's hearing. Heard and not seen Audible sound has frequencies between 20 Hz to 20 kHz. Human beings can hear audible sound. Sound waves with frequency above 20 kHz are called ultrasound waves. Sound waves with frequency below 20 Hz are called infrasound waves. Human beings cannot hear ultrasound waves and infrasound waves, but some animals, like bats and dolphins, use them. Older people have an even smaller hearing range. People are best at hearing sounds between 1000 Hz and 6000 Hz. The Doppler Effect When a sound source is moving towards someone, the frequency seems to increase. The same thing happens when someone moves toward the sound source. Frequency seems to decrease when someone moves away from a sound source. It also seems to decrease when the sound source moves away from someone. This is called the Doppler effect. References Halpern, Alvin, Erich Erlbach (1998). Beginning Physics II: Waves, Electromagnetism, Optics, and Modern Physics, pg. 50-56 Other websites Conversion of sound units and levels Sound calculations Basic English 850 words

Society is the term to describe human beings together (collective, the sum of their social networks and social interactions). The term comes from the Latin idea of societas, or the connection between friends or allies (friend or ally being socius). It can also mean a specific group of people who interact, as well as a wider society of which they are members. People form societies in order to gain greater benefits as a group than would be possible separately. Many animals beside humans also do this, such as wolves or eusocial insects. Sociology is the name for the study of society. A society is often considered in terms of citizenship, rights, and ethics. The strength and unity of any society's members' willingness to help each other is to be measured can be called social capital. A social contract sets out the rules and roles for this kind of cooperation. One kind of social contract is a constitution – which outlines to some extent what society in a given state is intended to look like. Related pages Civilization Culture Interpersonal relationship References

A suggestion is an idea that one suggests, or says is good for another (or others) to follow. Some people may agree to it, and some may disagree. If they disagree or have a different suggestion, the person who first suggested the idea will usually discuss with the other people and find a good conclusion that satisfies both and is good. Basic English 850 words

Spache Readability Formula is one method of finding out how hard a piece of writing is (its textual difficulty). The method compares words in a text to a list of words which are familiar in everyday writing. The words that are not on the list are called unfamiliar. The number of words per sentence are counted. This number and the percentage of unfamiliar words is put into a formula. The result is a reading age. Someone of this age should be able to read the text. Spache works best on texts that are for children under the age of eight. the formula; (0.141 * average sentence length)+(0.086 * percentage of difficult words)+0.839 = grade level According to Oleander Solutions (), the revised Spache Formula is: GL = (.121 * ASL) + (.082 *UW) + .659 Where: GL = U.S. grade level ASL = Average sentence length UW = Number of unique unfamiliar words Related pages Flesch-Kincaid Reading Level Language

Sport is commonly defined as an athletic activity that involves a degree of competition, such as netball or basketball. Some games and many kinds of racing are called sports. A professional at a sport is called an athlete. Many people play sports with their friends. They need coaches to teach or train teams or individuals how to do better. Sports can be played indoors or outdoors and by individuals or team. Sport. Different types of sports help our body in different ways. For children, sports play an extremely important part in their lives by providing all round development of the child, physically, mentally and emotionally. Some people like to watch other people play sports. Those who watch others playing sports are called fans. While some fans watch sports on television, others actually go to stadiums or other places where people pay to watch them in person. These fans are called spectators. People engage in many kinds of sports, for example: Athletics Angling Field athletics. Triple jump Pole vault High jump Hammer throw Discus throw Javelin throw Shot put Track athletics Sprint Middle distance race Long distance race Walking race Hurdle race Relay Steeplechase (sport) Cross-country race Marathon Acrobatics Bodybuilding Gymnastics Rhythmic gymnastics Figure skating Boxing Fencing Judo Wrestling Motor sports Auto racing Shooting Diving Golf Rowing Sailing (sport) Surfing Swimming Bobsled Skiing Freestyle skiing Ski jumping Games Tennis Baseball Softball Basketball Badminton-game Cricket-game Association football American football Australian Football Canadian football Gaelic football Rugby league football Rugby union football Flag football Polo Volleyball Dance Colorguard Marching band Esports Related pages Exercise Healthy lifestyle List of water sports Physical fitness Sports commentator Strength training

Science is what we do to find out about the natural world. Natural sciences include, chemistry, biology, geology, astronomy, and physics. Science uses mathematics and logic, which are sometimes called "formal sciences". Natural science makes observations and experiments. Science produces accurate facts, scientific laws and theories. 'Science' also refers to the large amount of knowledge that has been found using this process. Research uses the scientific method. Scientific research uses hypotheses based on ideas or earlier knowledge, which can be categorized through different topics. Then those hypotheses are tested by experiments. People who study and research science and try to find out everything about it are called scientists. Scientists study things by looking at them very carefully, by measuring them, and by doing experiments and tests. Scientists try to explain why things act the way they do, and predict what will happen. Scientific method Today, "science" usually refers to a way of pursuing knowledge, not just the knowledge itself. It is mainly about the phenomena of the material world. The Greek works into Western Europe from the 6th to 7th century B.C. revived "Philosophy". In the 17th and 18th centuries scientists increasingly sought to formulate knowledge in terms of laws of nature such as Newton's laws of motion. And during the 19th century, the word "science" became more and more associated with the scientific method itself. It was seen as a way to study the natural world, including physics, chemistry, geology and biology. It was also in the 19th century that the term scientist was created by William Whewell. He meant it tell the difference between those who looked for knowledge on nature from those who looked for other types of knowledge. The scientific method is the name given to the methods used by scientists to find knowledge. The main features of the scientific method are: Scientists identify a question or a problem about nature. Some problems are simple, such as "how many legs do flies have?" and some are very deep, such as "why do objects fall to the ground?" Next, scientists investigate the problem. They work at it, and collect facts. Sometimes all it takes is to look carefully. Some questions cannot be answered directly. Then scientists suggest ideas, and test them out. They do experiments and collect data. Eventually, they find what they think is a good answer to the problem. Then they tell people about it. Later, other scientists may agree or not agree. They may suggest another answer. They may do more experiments. Anything in science might be revised if we find out the previous solution was not good enough. An example A famous example of science in action was the expedition led by Arthur Eddington to Principe Island in Africa in 1919. He went there to record where the stars were around the Sun during a solar eclipse. The observation of where the stars were shown that the apparent star positions close to the Sun were changed. In effect, the light passing the Sun was pulled towards the Sun by gravitation. This confirmed predictions of gravitational lensing made by Albert Einstein in the general theory of relativity, published in 1915. Eddington's observations were considered to be the first solid proof in favour of Einstein's theory. Practical impacts of scientific research Discoveries in fundamental science can be world-changing. For example: {| class="wikitable" style="font-size:90%" |- ! Research !! Impact |- | Static electricity and magnetism (1600)Electric current (18th century) || All electric appliances, dynamo's, electric power stations, modern electronics, including electric lighting, television, electric heating, magnetic tape, loudspeaker, plus the compass and lightning rod. |- | Diffraction (1665) || Optics, hence fiber optic cable (1840s), cable TV and internet |- | Germ theory (1700) || Hygiene, leading to decreased transmission of infectious diseases; antibodies, leading to techniques for disease diagnosis and targeted anticancer therapies. |- | Vaccination (1798) || Leading to the elimination of most infectious diseases from developed countries and the worldwide eradication of smallpox. |- | Photovoltaics (1839) || Solar cells (1883), hence solar power, solar powered watches, calculators and other devices. |- | leading to special (1905) and general relativity (1916) || Satellite-based technology such as GPS (1973), satnav and communications satellites. |- | Radio waves (1887) || Used in broadcast: radio (1906) and television (1927) entertainment. It is used in telephony, emergency services, radar (navigation and weather forecasting), medicine, astronomy, wireless communications, and networking. Radio research led to microwave cooking. |- | Radioactivity (1896) and antimatter (1932) || Cancer treatment (1896), Radiometric dating (1905), nuclear reactors (1942) and weapons (1945), PET scans (1961), and medical research (with isotopic labelling) |- |X-rays (1896)|| Medical imaging, including computer tomography |- | Crystallography and quantum mechanics (1900) || Semiconductor devices (1906), hence modern computing and telecommunications including the integration with wireless devices: the mobile phone |- |Plastics (1907)||Starting with bakelite, many types of artificial polymers for numerous applications in industry and daily life |- |Antibiotics (1880's, 1928) || Salvarsan, Penicillin, doxycycline. In 2018 Amoxicillin and amoxicillin/clavulanic acid were the most frequently used. |- |Nuclear magnetic resonance (1930's) || Nuclear magnetic resonance spectroscopy (1946), magnetic resonance imaging (1971), functional magnetic resonance imaging (1990's). |- |Genomics (1990s)||Genomics = genetics + medicine. It is the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA (or RNA). This makes up its genes. Vaccines for viruses are built by genomics. |} Other features of science Not everyone completely agrees about how theories should be used or updated. Some philosophers and scientists say that scientific theories are only accepted for the time being. They last as long as they are the best explanation. When theories no longer explain the data, they are removed and replaced. Or, sometimes scientists will make a theory better rather than remove it, or they will keep on using the theory hoping that it will be made better eventually. Science is a way to get knowledge by getting rid of what is not true. Scientists must be very careful to make explanations that fit well with what they observe and measure. They compete to provide better explanations. An explanation might be interesting or pleasing, but if it does not agree with what other scientists really see and measure, they will try to find a better explanation. Before a scientific article is published, other scientists read the article. They decide whether the explanations make sense from the data. This is called peer review. After articles are published, other scientists will also check to see if the same experiments, observations or tests produce the same data again. Peer review and repeating experiments are the only way to be sure the knowledge is correct. Science makes models of nature, models of our universe, and medicine. There are many different sciences with their own names. However it is not right to say "science says" any one thing. Science is a process, not just the facts and rules believed at one time. Some types of science Natural sciences Biology Zoology Botany Genetics Ecology Physiology Astronomy Earth science Meteorology Geology Oceanography Physical sciences Physics Chemistry Social sciences Anthropology Psychology Sociology Economics Political science Social work Linguistics Formal and applied sciences Computer science Engineering Mathematics Statistics Medicine Related pages History of science Philosophy of science Science tourism References Other websites "How Do We Know What Is True?" (animated video; 2:52) Basic English 850 words

The Saint Lawrence River (; Tuscarora: Kahnawáʼkye; Mohawk: Kaniatarowanenneh, meaning "big waterway") is a big river in eastern North America. It flows between the Canadian province of Quebec & Ontario and the American state of New York, and through the major canadian city of Montreal. It is the third largest river in Canada. The river drains water from the Great Lakes into the Atlantic Ocean. It is more than three thousand kilometres long. The river meets the Atlantic Ocean in a big "estuary" or bay, the biggest in the world; this is called the Gulf of Saint Lawrence. The Canadian cities of Kingston, Montreal, Trois-Rivières and Quebec City are on this river. The Saint Lawrence Seaway allows ships to go up the river and through the Great Lakes right into the middle of North America. References Other websites Regional Geography of the St. Lawrence River Great Lakes St. Lawrence Seaway System Safe Passage: Aids to Navigation on the St. Lawrence – Historical essay, illustrated with drawings and photographs Annotated Bibliography on St. Lawrence County and Northern New York region. International Saint Lawrence River Board of Control Saint Lawrence River from The Canadian Encyclopedia Watch the Jacques Cousteau documentary, St. Lawrence: Stairway to the Sea The Steamboats "Sir James Kemp" and "Lord Dalhousie" on the River St. Lawrence, Upper Canada in 1833 by D.J. Kennedy, Historical Society of Pennsylvania Lawrence, Saint

Seville () is a city in the southern parts of Spain. A river called the Guadalquivir River goes through Seville. The city of Seville is the capital of the Spanish autonomous community Andalusia and of the province of Sevilla. People from Seville are called Sevillanos. History A very old story says that the city was started by the famous hero of Greece, named Hercules. The Romans when they came to Spain gave it the Latin name of Hispalis. Over time this changed to be spelled in English as Seville. The Arab Moors took the city when they invaded the country, and you can still see a lot of the buildings they built during their 800-year stay in Spain (711-1492). In 1992 Seville was the place for the Expo 92. There is a beautiful bridge across the Guadalquivir River called Puente del Alamillo. It was thought up by Santiago Calatrava a famous building expert. Seville is famous for its hot summer weather. Education University of Seville. This is the oldest university in Sevilla. It is located near the Centro, or center of the city, across the street from Plaza de España and Parque Maria Luisa. Pablo de Olavide University. This website is located outside the main city of Sevilla, but is very easy to access using the subway system. It take about 30 minutes to get from the center of town to Pablo de Olavide on the subway. Menéndez Pelayo International University-Sevilla . This school is not your typical university. Only students who are studying abroad with International Studies Abroad attend classes at this school. It is lcoated near the Centro and Alfalfa Barrio. Sports Seville is the home town of two soccer teams, Sevilla FC (often simply called "El Sevilla") and Real Betis Balompié (often called "El Betis"). Gallery Other websites Sevilla Guide City councils Capital cities in Spain

Salami is a sausage that first came from Italy. The name comes from the Italian salare meaning to make something salty. The original salami was made from a mix of chopped pork and salt which was dried using air in a casing. Now there are many types of salamis made in some countries. Nearly all are seasoned with a combination of herbs and spices in addition to salt. Salamis are now sometimes smoked or cooked before air drying. Some kinds are made of beef while others mix beef and pork. Most, if not all Italian salamis have garlic in them, but few German kinds do, for example. Some, like a few salamis from Spain, include paprika or chili. The difference between some types is in how coarse or fine the meat is chopped. Some "light" salami might add turkey or chicken to reduce both fat and calories. Many salamis are named after the city or region where they come from. Some examples are Arles, Genoese, Hungarian, and Milano salamis. Sausage

Special English is a simple form of the English language. It is used by a public radio station called Voice of America, run by the United States government in Special English programs every day. Its news and feature programs are read more slowly than usual, using fewer English words and simple grammar. The contents of Special English programs are much easier to understand. Special English is clearer and simpler, and it uses shorter sentences. It can also help someone whose English is weak to improve his or her English. In some countries, for example China, Special English is popular among people learning English. Special English was first used on October 19, 1959. Special English started in that year as one of radio programs by the Voice of America. This broadcasts adopt slow pace and simple English in order to increase understanding for millions of listeners. It is now also known as "Learning English". Details Special English started in 1959. It was developed as an experimental radio program to spread information on news and culture to people outside the United States. Programs on VOA use a simpler English within about 1,500 words. And reports are paced 1/3 slower than regular English in order to allow listeners to increase a better understanding. This means broadcasters speak at about two-thirds the speed of conversational English. But far from sounding like a record played at the wrong speed. It now deals with various topics to keep interest of listeners, such as news, business, science, and culture. Stories are written in clear. To be a Special English broadcaster, he or she needs a complicated skill that takes months of training. The training includes a professional voice trainer who teaches how to breathe properly and pronounce clearly. A chief of Special English at VOA said, "People in this country have likely never heard of Special English," and also said, "and, if they have, they often don't understand the significance of it to people in other countries." One VOA staff explains that the main goal of Special English is for the listener to understand the content of what is being broadcast, and to make steady progress in English. “There is a fine line between being simplified and simplistic,” he says. “We never want to cross that line.” So when necessary, more “advanced” English words are used and the meanings made clear, so the stories never suffer from incomplete information. Students and teachers in other countries say Special English is a good learning tool. About programs Some of popular programs on VOA follow. Arts & Culture American Stories Health & Lifestyle U.S.History Science & Technology Words & Their Stories Learning English Broadcast VOA broadcast a program titled 'Willis Conover, the Voice of Jazz, Is Now Online" in the past, as Willis Conover became a famous host at Music USA. Notes Related pages Voice of America Wikipedia:VOA Special English Word Book Other websites The VOA Special English Web Page VOA Special English Word Book - 1,500 words used on VOA Special English broadcasts Voice of America Special English Study - Online quizzes, listen and read along, crossword puzzles and more. (By Charles Kelly) English learning lessons using Voice of America Special English English language

Sausage is a food made of ground-up or chopped-up meat. It often has spices in it and is covered in a casing. Traditionally, a sausage casing is made of animal intestine, but can sometimes be made of plastic. There are many forms of sausages, including hot dog, pepperoni, bologna, and salami. Sausages often have meat from the animal's head, lips, cheeks, ears and other parts. Some have blood in them. German and British sausages normally have a lot of "rusk," or bread crumbs, and they are less meaty than sausages from other countries. Vegetarian or vegan sausages are often made of products other than animal products, such as tofu. Sausages may be used as a meal, in a sandwich, or in other foods like stews. Sausages can be eaten as whole pieces, or they can be chopped up as already cooked pieces. Germany has regions that have special kinds of sausage. Sausages are some of the oldest German foods. Name origin The word "sausage" was first used in English in the mid-15th century. During the mid-15th century, the word "sausage" was spelled as "sawsyge". The word "sawsyge" came from Old North French saussiche (Modern French saucisse)". The French word came from Vulgar Latin salsica (sausage), from salsicus (seasoned with salt). Types of sausage Andouille Blood sausage, a type of sausage made of animal blood Bratwurst (a German/Austrian variety) Breakfast sausage Chorizo Fish Knockwurst Landjäger Mortadella Salami References Other websites

Slang are words that are informal. Usually each generation or social group has its own slang - for example, older people can have trouble understanding the slang of younger people. On the other hand, younger people often understand, but find silly or old-fashioned, the slang of older people. Over time, language tends to get more complex, since new words enter much faster than old words leave. Over time, slang almost always becomes part of the language, and approved for use by all. It has also happened that some words used in Anglo-Saxon for bodily functions became thought of as profanity or rude after they were replaced by Latinate words like "urinate", "defecate" and "copulate" - which polite people were supposed to use after the Norman conquest of England in 1066. This was in part a way of making poor people (who spoke Anglo-Saxon) all appear to be rude, while more powerful people (who spoke Norman) appeared to be polite - one way that etiquette can develop, and reinforce power structure. This is only one example from history of how racism can be a reason for defining one group's language as 'slang' and another as 'correct'. Wanting to have rules of grammar that do not change and the same vocabulary used by everyone for better communication is another reason that is often given for defining one group's language as correct. An "idiom" can be slang, but it can also be a metaphor that becomes part of the culture. Two examples of slang are 'wassup' and 'dunnow'. 'Wassup' usually means 'What is up?' (as in, 'How are you?'), and 'dunnow' usually means 'I don't know'. Related pages Jargon Political correctness

A social contract or political contract is a perceived agreement among the people of a state about the rules that will define their government. These rules are usually called laws. Laws help to make sure people have rights and that their rights are protected. One kind of social contract is a constitution. A constitution says how decisions are made, and sets limits on the powers of leaders and other people who have authority. In the Age of Enlightenment, philosophers Thomas Hobbes, John Locke and Jean-Jacques Rousseau wrote books about social contracts. They saw good government as coming from social contracts. Rousseau wrote a book called The Social Contract. Both the United States Declaration of Independence and United States Constitution use the theory of social contracts. Related pages Constitution Political economy Rule of law Law

Social capital is the willingness of people to help each other. It often replaces money which people would use to buy the same help. Society works best when there is plenty of social capital. The less social capital there is, the more social problems there usually are. If there is no social capital, war and revolution often results. People who have no money and cannot get help from society may have to agree to do things they do not want to do, or force others to do things they do not want to. Organized crime grows in this way, and so do forced labour and slavery. Most ways of measuring social capital have to do with trust - people who trust that favours and help will be available when they need it will favour and help others more. Those who are seen as trying to get a free ride will get much less help. A social climber tries to earn social capital by making friends with those who have it but without actually helping. Some call this kind of person a social parasite. They are very hard to detect, unlike people who cheat or commit fraud. When there are too many of these kinds of people, especially when they are politicians, people begin to mistrust their government. Rather than work with a political party to change law, they may start to look for direct revenge for things. Social capital is a lot like real capital. The more money a person or a society has, the easier it is to do things and the better off people are. The less money, the more difficult things become and the worse people feel. Related pages Human capital Social status Other websites The Social Capital Foundation Social sciences Economics

A site is a real fixed physical location where something will or has happened or a place where something is. Uses Uses in buildings It is used very often in building trades to mean the place where a building will go up. Uses in gravesites A gravesite is a place where a person will be buried after they die. Uses in work The words onsite and offsite refer to work that must take place on the site, or which can take place somewhere else. For instance, a prefabricated building can be "built offsite" and then "moved onsite". Use on the internet Site is also a common abbreviation in net jargon for "website". In this case no real physical location exists other than the place where the computers are, and one "goes to the site" simply by using a web browser to "go to" that URL. This is a conceptual metaphor. It can be confusing. Someone who uses it is also likely using other jargon.

Subtraction is the arithmetic operation for finding the difference between two numbers, though it can also be generalized to other mathematical objects such as vectors and matrices. The special names of the numbers in a subtraction expression are, minuend - subtrahend = difference. For example, the expression 7 - 4 = 3 can be read as "seven minus four equals three," "seven take away four leaves three," or "four from seven leaves three." If the minuend is less than the subtrahend, the difference will be a negative number. For example, 17 - 25 = -8 . This can be read as "Seventeen minus twenty-five equals negative eight." Subtraction is how cash registers determine the change a buyer receives, when the buyer pays with more money than the purchase cost. Related pages Addition Division (mathematics) Multiplication Negative number Order of operations References Arithmetics

String theory tries to model the four known fundamental interactions—gravitation, electromagnetism, strong nuclear force, weak nuclear force—together in one theory. This tries to resolve the alleged conflict between classical physics and quantum physics by elementary units—the one classical force: gravity, and a new quantum field theory of the other three fundamental forces. Einstein had sought a unified field theory, a single model to explain the fundamental interactions or mechanics of the universe. Today's search is for a unified field theory that is quantized and that explains matter's structure, too. This is called the search for a theory of everything (TOE). The most prominent contender as a TOE is string theory converted into superstring theory with its six higher dimensions in addition to the four common dimensions (3D + time). Some superstring theories seem to come together on a shared range of geometry that, according to string theorists, is apparently the geometry of space. The mathematical framework that unifies the multiple superstring theories upon that shared geometrical range is M-theory. Many string theorists are optimistic that M-theory explains our universe's very structure and perhaps explains how other universes, if they exist, are structured as part of a greater "multiverse". M theory/supergravity theory has 7 higher dimensions + 4D. Background Introductions to string theory that are designed for the general public must first explain physics. Some of the controversies over string theory result from misunderstandings about physics. A common misunderstanding even for scientists is the presumption that a theory is proved true in its explanation of the natural world wherever its predictions are successful. Another misunderstanding is that earlier physical scientists, including chemists, have already explained the world. This leads to the misunderstanding that string theorists began making strange hypotheses after they became unaccountably "set free from truth". Classical realm Newtonian physics Newton's law of universal gravitation (UG), added to the three Galilean laws of motion and some other presumptions, was published in 1687. Newton's theory successfully modeled interactions among objects of a size we can see, a range of phenomena now called the classical realm. Coulomb's law modeled electric attraction. Maxwell's electromagnetic field theory unified electricity and magnetism, while optics emerged from this field. Light's speed remained about the same when measured by an observer traveling in its field, however, although addition of velocities predicted the field to be slower or faster relative to the observer traveling with or against it. So, versus the electromagnetic field, the observer kept losing speed. Still, this did not violate Galileo’s Principle of relativity that says the laws of mechanics work the same for all objects showing inertia. By law of inertia, when no force is applied to an object, the object holds its velocity, which is speed and direction. An object either in uniform motion, which is constant speed in an unchanging direction, or staying at rest, which is zero velocity, experiences inertia. This exhibits Galilean invariance—its mechanical interactions proceeding without variation—also called Galilean relativity since one cannot perceive whether one is at rest or in uniform motion. Relativity theory Special relativity In 1905, Einstein's special theory of relativity explained the accuracy of both Maxwell's electromagnetic field and Galilean relativity by stating that the field's speed is absolute—a universal constant—whereas both space and time are local phenomena relative to the object's energy. Thus, an object in relative motion shortens along the direction of its momentum (Lorentz contraction), and its unfolding of events slows (time dilation). A passenger on the object cannot detect the change, as all measuring devices aboard that vehicle have experienced length contraction and time dilation. Only an external observer experiencing relative rest measures the object in relative motion to be shortened along its travel pathway and its events slowed. Special relativity left Newton's theory—which states space and time as absolute—unable to explain gravitation. By the equivalence principle, Einstein inferred that being under either gravitation or constant acceleration are indistinguishable experiences that might share a physical mechanism. The suggested mechanism was progressive length contraction and time dilation—a consequence of the local energy density within 3D space—establishing a progressive tension within a rigid object, relieving its tension by moving toward the location of greatest energy density. Special relativity would be a limited case of a gravitational field. Special relativity would apply when the energy density across 3D space is uniform, and so the gravitational field is scaled uniformly from location to location, why an object experiences no acceleration and thus no gravitation. General relativity In 1915, Einstein's general theory of relativity newly explained gravitation with 4D spacetime modeled as a Lorentzian manifold. Time is one dimension merged with the three space dimensions, as every event in 3D space—2D horizontally and 1D vertically—entails a point along a 1D time axis. Even in everyday life, one states or implies both. One says or at least means, "Meet me at building 123 Main Street intersecting Franklin Street in apartment 3D on 10 October 2012 at 9:00PM". By omitting or missing the time coordinate, one arrives at the correct location in space when the sought event is absent—it is in the past or future at perhaps 6:00PM or 12:00AM. By converging space and time and presuming both relative to the energy density in the vicinity, and by setting the only constant or absolute as not even mass but as light speed in a vacuum, general relativity revealed the natural world's previously unimagined balance and symmetry. Every object is always moving at light speed along a straight line—its equivalent, on a curved surface, called geodesic or worldline—the one pathway of least resistance like a free fall through 4D spacetime whose geometry "curves" in the vicinity of mass/energy. An object at light speed in a vacuum is moving at maximal rate through 3D space but exhibits no evolution of events—it is frozen in time—whereas an object motionless in 3D space flows fully along 1D time, experiencing the maximal rate of events' unfolding. The displayed universe is relative to a given location, yet once the mass/energy in that vicinity is stated, Einstein's equations predict what is occurring—or did occur or will occur—anywhere in the universe. The popularized notion that relative in Einstein's theory suggests subjective or arbitrary was to some regret of Einstein, who later thought he ought have to named it general theory. Cosmology The electromagnetic field's messenger particles, photons, carry an image timelessly across the universe while observers within this field have enough flow through time to decode this image and react by moving within 3D space, yet can never outrun this timeless image. The universe's state under 400 000 years after the presumed big bang that began our universe is thought to be displayed as the cosmic microwave background (CMB). In 1915, the universe was thought to be entirely what we now call the Milky Way galaxy and to be static. Einstein operated his recently published equations of the gravitational field, and discovered the consequence that the universe was expanding or shrinking. (The theory is operable in either direction—time invariance.) He revised the theory add a cosmological constant to arbitrarily balance the universe. Nearing 1930, Edwin Hubble's telescopic data, interpreted through general relativity, revealed the universe was expanding. In 1916 while on a World War I battlefield, Karl Schwarzschild operated Einstein's equations, and the Schwarzschild solution predicted black holes. Decades later, astrophysicists identified a supermassive black hole in the center of perhaps every galaxy. Black holes seem to lead galaxy formation and maintenance by regulating star formation and destruction. In the 1930s, it was noticed that according to general relativity, galaxies would fall apart unless surrounded by invisible matter holding a galaxy together, and by the 1970s dark matter began to be accepted. In 1998 it was inferred that the universe's expansion, not slowing, is accelerating, indicating a vast energy density—enough to accelerate both visible matter and dark matter—throughout the universe, a vast field of dark energy. Apparently, under 5% of the universe's composition is known, while the other 95% is mysterious—dark matter and dark energy. Quantum realm Strange mechanics By the 1920s, to probe the operating of the electromagnetic field at minuscule scales of space and time, quantum mechanics (QM) was developed. Yet electrons—the matter particles that interact with the photons that are the electromagnetic field's force carriers—would appear to defy mechanical principles altogether. None could predict a quantum particle's location from moment to moment. In the slit experiment, an electron would travel through one hole placed in front of it. Yet a single electron would travel simultaneously though multiple holes, however many were placed in front of it. The single electron would leave on the detection board an interference pattern as if the single particle were a wave that had passed through all the holes simultaneously. And yet this occurred only when unobserved. If light were shone on the expected event, the photon's interaction with the field would set the electron to a single position. By the uncertainty principle, any quantum particle's exact location and momentum cannot be determined with certainty, however. The particle's interaction with the observation/measurement instrument deflects the particle such that greater determination of its position yields lower determination of its momentum, and vice versa. Field theory quantized By extending quantum mechanics across a field, a consistent pattern emerged. From location to adjacent location, the probability of the particle existing there would rise and fall like a wave of probability—a rising and falling probability density. When unobserved, any quantum particle enters superposition, such that even a single particle fills the entire field, however large. Yet the particle is not definitely anywhere in the field, but there at a definite probability in relation to whether it was had been at the adjacent location. The waveform of Maxwell's electromagnetic field was generated by an accumulation of probabilistic events. Not the particles, but the mathematical form, was constant. Setting the field to special relativity permitted prediction of the complete electromagnetic field. Thus arose relativistic quantum field theory (QFT). Of the electromagnetic field, it is relativistic quantum electrodynamics (QED). Of the weak and electromagnetic fields together, it is relativistic electroweak theory (EWT). Of the strong field, it is relativistic quantum chromodynamics (QCD). Altogether, this became the Standard Model of particle physics. Division in physics When the Standard Model is set to general relativity in order to include mass, probability densities of infinity appear. This is presumed incorrect, as probability ordinarily ranges from 0 to 1—0% to 100% probability. Some theoretical physicists suspect that the problem is in the Standard Model, which represents each particle by a zero-dimensional point that in principle can be infinitely small. Yet in quantum physics, the Planck's constant is the minimum energy unit that a field can be divided into, perhaps a clue to the smallest size a particle can be. So there is a quest to quantize gravity—to develop a theory of quantum gravity. Concept Framework String conjectures that on the microscopic scale, Einstein's 4D spacetime is a field of Calabi-Yau manifolds, each containing 6 space dimensions curled up, thus not extended into the 3 space dimensions presented to the classical realm. In string theory, each quantum particle is replaced by a 1D string of vibrating energy whose length is the Planck length. As the string moves, it traces width, and thus becomes 2D, a worldsheet. As a string vibrates and moves within the 6D Calabi-Yau space, the string becomes a quantum particle. With this approach, the hypothetical graviton—predicted to explain general relativity—emerges easily. Theories String theory began as bosonic string theory, whose 26 dimensions act as many fewer. Yet this modeled only bosons, which are energy particles, while omitting fermions, which are matter particles. So bosonic string theory could not explain matter. Yet by adding supersymmetry to bosonic string theory, fermions were achieved, and string theory became superstring theory, explaining matter, too. (In versions of quantum field theory that include supersymmetry (SUSY), each boson has a corresponding fermion, and vice versa. That is, each energy particle has a corresponding matter particle, and each matter particle has a corresponding energy particle, yet the unobservable partner is more massive and thus super. These superpartners might seem an extravagant prediction, yet many theorists and experimentalists favor supersymmetric versions of the Standard Model, whose equations must otherwise be tweaked extravagantly and sometimes arbitrarily to maintain predictive success or mathematical consistency, but with the superpartners align.) Controversies Untestable—unscientific? String theory's claim that all molecules are strings of energy has drawn harsh criticism. There are many versions of string theory, none quite successfully predicting the observational data explained by the Standard Model. M theory is now known to have countless solutions, often predicting things strange and unknown to exist. Some allege that string theorists select only the desired predictions. The allegation that string theory makes no testable predictions is false, as it makes many. No theory—a predictive and perhaps explanatory model of some domain of natural phenomena—is verifiable. All conventional physical theories until the Standard Model have made claims about unobservable aspects of the natural world. Even the Standard Model has various interpretations as to the natural world. When the Standard Model is operated, it is often made a version with supersymmetry, doubling the number of particle species so far identified by particle physicists. None can literally measure space, yet Newton postulated absolute space and time, and Newton's theory made explicit predictions, highly testable and predictively successful for 200 years, but the theory was still falsified as explanatory of nature. Physicists accept that there exists no such attractive force directly attracting matter to matter, let alone that the force traverses the universe instantly. Nevertheless, Newton's theory is still paradigmatic of science. Hidden dimensions? The idea of hidden dimensionality of space can seem occult. Some theorists of loop quantum gravity—a contender for quantum gravity—regard string theory as fundamentally misguided by presuming that space even has a shape until particles shape it. That is, they do not doubt that space takes various shapes, simply regard the particles as determining space's shape, not the other way around. The spacetime vortex predicted by general relativity is apparently confirmed. If interpreted as naturally true, the Standard Model, representing a quantum particle as a 0D point, already indicates that spacetime is a sea of roiling shapes, quantum foam. String theorists tend to believe nature more elegant, a belief that loop theorist Lee Smolin dismisses as romantic while using biology's Modern Synthesis as a rhetorical device. Experiments to detect added spatial dimensions have so far failed, yet there is still the possibility that signs of them can emerge. So many solutions? M theory has many trillions of solutions. Leonard Susskind, a leader of string theory, interprets string theory's plasticity of solutions as paradoxical support resolving the mystery of why this universe exists, as M theory shows it but a variant of a general pattern that always approximately results. General relativity has brought many discoveries that in 1915 were all but unimaginable except in fiction. A solution of Einstein's equations that sought to explain quantum particles' dynamics, the Einstein-Rosen Bridge predicts a shortcut connecting two distant points in spacetime. Commonly called a wormhole, the Einstein-Rosen Bridge is doubted but not disproved, showing either that not all consequences of a theory must be accurate or that reality is quite bizarre in ways unobservable. Many worlds Even the Standard Model of particle physics suggests bizarre possibilities that populist accounts of science either omit or mention as unexplained curiosities. The theory conventionally receives the Copenhagen interpretation, whereby the field is only possibilities, none real until an observer or instrument interacts with the field, whose wavefunction then collapses and leaves only its particle function, only the particles being real. Yet wavefunction collapse was merely assumed—neither experimentally confirmed nor even mathematically modeled—and no variance from either the wavefunction in the quantum realm or the particle function in the classical realm has been found. In 1957 Hugh Everett described his "Relative state" interpretation. Everett maintained that the wavefunction does not collapse, and since all matter and interactions are presumed to be built up from quantum waveparticles, all possible variations of the quantum field—indicated by the mathematical equations—are real and simultaneously occurring but different courses of history. By this interpretation, whatever interacts with the field joins the field's state that is relative to the observer's state—itself a waveform in its own quantum field—while the two simply interact in a universal waveform never collapsing. By now, many physicists' interpretation of the apparent transition from the quantum to the classical realms is not wavefunction collapse, but quantum decoherence. In decoherence, an interaction with the field takes the observer into only one determinant constellation of the quantum field, and so all observations align with that new, combined quantum state. Everett's thesis has inspired Many worlds interpretation, whereby within our universe are predicted to be virtually or potentially infinite parallel worlds that are real, yet each a minuscule distance from the other worlds. As each world's waveform is universal—not collapsing—and its mathematical relations are invariant, parallel worlds simply fill the gaps and do not touch. Many universes Einstein doubted that black holes, as predicted by the Schwarzschild solution, are real. Some now conjecture that black holes do not exist as such but are dark energy, or that our universe is both—a black hole and dark energy. The Schwarzschild solution of Einstein's equations can be maximally extended to predict a black hole having a flip side—another universe emerging from a white hole. Perhaps our universe's big bang was half of a big bounce, something's collapse down to a black hole, and our universe popping out its other side as a white hole. Particles are strings? Physicists widely doubt that quantum particles are truly 0D points as represented in Standard Model, which offers formalism—mathematical devices whose strokes predict phenomena of interest upon input of data—not interpretation of the mechanisms determining those phenomena. Yet string theorists do tend to optimistically conjecture that the strings are both real and explanatory, not merely predictive devices. It is far beyond the capacity of today's particle accelerators to propel any probing particles at energy levels high enough to overcome a quantum particle's own energy and determine whether it is a string. Yet this limitation also exists on testing other theories of quantum gravity. Developments suggest other strategies to "observe" the structure of quantum particles. Paradoxically, even if testing confirmed that particles are strings of energy, that still would not conclusively prove even that particles are strings, since there could be other explanations, perhaps an unexpected warpage of space although the particle was a 0D point of true solidity. Even when predictions succeed, there are many possible explanations—the problem of underdetermination—and philosophers of science as well as some scientists do not accept even flawless predictive success as verification of the successful theory's explanations if these are posed as offering scientific realism, true description of the natural world. Matter is energy? Talk of particle physicists testing theoretical physicists' predicted particles by colliding particles in accelerators suggests that quantum particles are tiny Newtonian particles that experimentalists crack open to reveal their structure. Instead, when two particles, each of a certain mass—measured in terms of energy as electronvolts—are collided, they can combine into a particle of that combined mass/energy, and the generated particle is "observed" for correspondence with the prediction. It is not controversial among physicists that all particles are energy. Loop theorists, sometimes in rivalry with string theory, claim that spacetime itself converts into the particles. Matter's being a special variant of energy was a consequence of Einstein's special theory of relativity, and thereupon Einstein formalized the mass-energy equivalence, E=mc2. When sufficiently energetic photons collide, they can combine and generate matter—matter creation. All particles have antiparticles, and atoms of matter have antiatoms of antimatter, whose union annihilates the particles and matter while leaving energy. Developments An inspiring development is discovery of mirror symmetry, whereby Calabi-Yau spaces tend to come in pairs such that solutions previously difficult within the extreme vibrational mode of one string can be solved by through the mirror Calabi-Yau space's geometry in its opposite range. String theory is usually solved through conformal field theory, a quantum field theory on 2D space. It is confirmed that molecules can collapse to 2D. And the electron, long presumed an elementary particle, apparently splits into three entities separately carrying the electron's three degrees of freedom when the molecules that contain the electrons are channeled through a 1D pathway. Related pages M-theory Notes

A scientist is a person who studies or has mastered the field in science. A scientist tries to understand how our world, or other things, work. Scientists make observations, ask questions and do extensive research work in finding the answers to many questions others may not know about. Scientists have researched many things. Scientists may work in laboratories for governments, companies, schools and research institutions. Some scientists teach at universities and other places and train people to become scientists. Scientists often do experiments to find out more about reality, and sometimes may repeat experiments or use control groups. Scientists who are doing applied science try to use scientific knowledge to improve the world. Types of scientists Scientists can work in different areas of science. Here are some examples: Scientists that study physics are physicists. Scientists that study chemistry are chemists. Scientists that study biology are biologists Scientists that study rocks are geologists Scientists that study plants are botanists Scientists that study minds are psychologists Scientists that study farming are agricultural scientists Related pages History of science List of scientists from Africa List of scientists from Asia List of scientists from Europe List of scientists from North America List of scientists from Oceania List of scientists from South America Science occupations

A soapbox is a temporary platform used to give a speech. During the 19th century, soap was transported in wooden boxes. When a person had new or unusual ideas, and wanted to talk to a crowd about them, sometimes he or she would stand on an empty soapbox so that everyone could see and hear the talk well. People sometimes use the word "soapbox" to mean a place to say new or unusual things. References Human communication

The word supernatural (from ) is used for things that some people believe are real, but that are not part of nature or inexplicable by the scientific laws of nature. Because we cannot prove whether these things are real, people often disagree about these things. Some say that we should talk about things without talking about the supernatural, because we cannot prove that supernatural things are real. Other people say that although we cannot prove supernatural things in a scientific way, they are real. Some examples of supernatural things or examples are: magic miracles precognition demonic possession souls, spirits or ghosts monsters yōkai grim reaper angels devils, asuras or demon kami UFOs legendary creatures God or gods parapsychology Related pages Religion Belief Superstition Ritual Near death experiences Religion

A spirit is considered to be the part of a being that is not the body. Other words with the same meanings are soul and ghost. When a body is alive, it has a spirit in it. Death is when the spirit separates from the body. Christians believe that spirits exist in Heaven or Hell. (See 1 Timothy 3:16, 4:1) Spiritualists believe that spirits can talk with people, or change things in the world. Many religions forbid communicating with such spirits in any way, (see Leviticus 19:31) but a few include this as part of their practice. Another use of spirit means the main purpose or meaning of a sentence or document. For example, the "spirit of a law" is the true meaning of the law which the creator wanted. This phrase is often used when the words and sentences of a law could mean more than one thing, but a judge must decide what meaning is correct. Spirituality

A seed is the part of a seed plant which can grow into a new plant. It is a reproductive structure which disperses, and can survive for some time. A typical seed includes three basic parts: (1) an embryo, (2) a supply of nutrients for the embryo, and (3) a seed coat. There are many different kinds of seeds. Some plants make a lot of seeds, some make only a few. Seeds are often hard and very small, but some are larger. The coconut is as big as a child's head, but it contains more than just a seed. At the start, seeds are dormant (resting inside their coat) for a while. When the seed is ready to develop, it needs water, air and warmth but not sunlight to become a seedling. Seeds carry the food that helps the new plant begin to grow. This food store is in the endosperm, and/or in the cotyledons. Many kinds of seeds are good food for animals and people. The many kinds of grain that people grow, such as rice, wheat, and maize, are all seeds. Seeds are often inside fruits. Development from the seed A seed, though not active, is a tiny living thing. It contains the embryo of the future plant, which is not changing or developing: it is dormant. The common idea is that the seed "sleeps" until it gets what it needs to wake up. That is not correct. Different seeds have different habits, no doubt adapted to their habitat. There are different kinds of resting stages in seeds: 1. Seed dormancy: means the seed does not develop for a while even when conditions are suitable.p98 Delayed germination (development) allows time for dispersal. Changes take place inside the seed which sooner or later make it germinate. The details vary hugely between species. 2. Seed hibernation: fails to germinate because conditions are not right. Growth is triggered by particular events in the environment. Details of the triggers are known for some, but not all, seeds. Rain, fire, ground temperature, are examples. Many seeds only germinate after they have been eaten and passed through the digestive system of an animal. This also is a dispersal method. When a seed germinates ("wakes up"), it begins to grow into a little plant called a seedling. It uses the soft fleshy material inside the seed for nutrients (food) until it is ready to make food on its own using sunlight, water and air. Most seeds germinate underground where there is no sunlight. The plant does not need the nutrients in soil for a few days or weeks, because the seed has all the things it needs to grow. Later, though, it will begin to need sunlight. If there is sunlight, the plant will use it to grow healthy. If there is no light, the plant will still grow for a while, but its plastids will not mature: the chlorophyll does not turn green. If the plant does not get enough light, it will eventually die. It needs light to make food for itself when the reserve in the seed runs out. The oldest carbon 14-dated seed that has grown into a plant was a Judean date palm seed about 2,000 years old, recovered from excavations at Herod the Great's palace on Masada in Israel. It was germinated in 2005. The largest seed is produced by the Coco de mer, or "double coconut palm", Lodoicea maldivica. The entire fruit may weigh up to 23 kilograms (50 pounds) and usually contains a single seed. Origin and evolution Seeds have been an important development in the reproduction and spread of conifers and flowering plants. Plants such as mosses, liverworts and ferns do not have seeds, and use unprotected spores and other methods to propagate themselves. Before the upper Devonian period, land plants, like modern ferns, reproduced by sending spores into the air. The spores would land and become new plants only in favourable conditions. Spores have little food stored, and may be just single cells rather than embryos. The evolution of seeds changed the plant life cycle by freeing plants from the need for external water for sexual reproduction, and by providing protection and nutrients for the developing embryo. These functions allowed plants to expand beyond the immediate neighbourhood of water sources. They were able to exploit environments which were drier and more upland.p92 This can be seen by the success of seed plants in important biological niches on land, from forests to grasslands both in hot and cold climates. The present-day seed plants are the Gymnosperms, with naked seeds, and the Angiosperms with covered seeds, usually fruits. The first true seeds are from the upper Devonian 370–354 million years ago, which is probably the theatre of their first evolutionary radiation. The earliest seed-producing trees were in the forests of the Carboniferous period.p112 The seed plants steadily became one of the most important elements of nearly all ecosystems. References Basic English 850 words Plant anatomy

A sail is a large piece of cloth on the top of some boats. The wind goes around the sail and makes the boat move through the water. The piece that the sail is attached to is called a mast. Some boats have many sails, and some have only one. Usually, small boats have only one sail, and bigger boats have more. Boats with sails are called sailing boats. There are many different names for different kinds of sailing boats with different kinds of sails. Before people made boats with engines that used coal or oil, sailing boats were an important way to travel across oceans. Now they are not so important for transport, but they are still used for recreation and competition. Sail types Modern sails can be classified into three main categories: A mainsail is a sail located behind the main mast of a sailing vessel. A headsail also known as the jib sail, is any sail set forward of the main mast. A spinnaker or downwind sail (also termed Kite). Special-purpose sails are often a variation of the three main categories. A staysail is a fore-and-aft rigged sail whose luff can be attached to a forestay running from a mast to the bowsprit. High-performance yachts, in particular some catamarans such as the International C-Class Catamaran, have used or use rigid wing sails, which are said to perform better than traditional soft sails. In particular, a rigid wing sail was used by Stars and Stripes, the defender which won the 1988 America's Cup, and by USA-17, the challenger which won the 2010 America's Cup. Most modern yachts, including bermuda rig, ketch and yawl boats, have a sail "inventory" which usually includes more than one of these types of sails. Although the mainsail is “permanently” hoisted while sailing, headsails and spinnakers can be changed depending on the particular weather conditions to allow better handling and speed. References Other websites The quest for the perfect sailshape The Headsail: YouTube The Mainsail; YouTube Basic English 850 words Boats

The word Spanish means: from or about the country of Spain, such as a person from Spain or food from Spain Spanish people the Spanish language Spanish Empire Other use Hispanic

Skin is the outside covering of mammals and some other animals. It has many purposes. First of all, it is a defense against the entry of pathogens such as bacteria and parasites. Second, it regulates (keeps in control) the body's temperature. It allows evaporation from its surface, and adjusts it. It is a physical defense, very strong in some animals, but rather weak in humans. The skin and hair on mammals has several purposes. In addition to temperature regulation and defense, some hair is used for signaling. Most animals add other defenses to their skin. Mammals have hair or fur on their skin. Birds have feathers on their skin. Most fish, and reptiles, like snakes and lizards, have scales on their skin. Humans can have different skin colours like black people and white people depending on their race and has to do with genetics. The skin is actually the largest organ of the human body. Without skin, humans would easily get infected with diseases. Skin helps regulate body temperature. Skin lowers the potentially harmful effects of UV rays. As part of the immune system, skin can help warn people to certain diseases. Clean skin is important to health, and all mammals groom their hair and skin. Skin care is much work. Skins can be made into leather. Leather is sometimes used to make shoes, bags, and balls. Other things can be said to have "skins". People often say that fruits, such as apples, bananas, grapes, kiwis, and strawberrys, and vegetables, such as potatoes, have "skins". See also Human skin colour Other websites References Basic English 850 words

A search engine is a website that allows users to look up information on the World Wide Web (WWW), part of the Internet. The search engine will achieve this by looking at many web pages to find matches to the user's search inputs. It will return results ranked by relevancy and popularity by the search engine. Some popular search-engines are Google Search, Yahoo! Search, Ask.com, Forestle and Bing. Older services include Webcrawler, Lycos, and Alta Vista. To use a search engine you must enter at least one keyword in to the search box. Usually an on-screen button must be clicked on to submit the search. The search engine looks for matches between the keyword(s) entered and its database of websites and words. After the user inputs their search or query into the search bar, a list of results will appear on the screen known as search engine results page (SERP). This list of webpages contains matches related to the user's query in a particular order determined by a ranking system. Most search engine will remove "spam" pages from the list of results to provide a better list of results. The user can then click on any of the links to go to that webpage. Search engines are some of the most advanced websites on the web. They use special computer code to sort the web pages on SERPs. The most popular or highest quality web pages will be near the top of the list. When a user types words into the search engine, it looks for web pages with those words. There could be thousands, or even millions, of web pages with those words. So, the search engine helps users by putting the web pages it thinks the user wants first. Search engines are very useful to find information about anything quickly and easily. Using more keywords or different keywords improves the results of searches. A search service may also include a portal with news, games, and more information besides a search engine. Yahoo! has a popular portal, and MSN Search is part of the MSN portal, while Google has a simple design on its front page. Search services usually work without charging money for finding sites, and are often supported with text or banner advertisements. Crawling Search engines use robots to ‘crawl’ online content. The process of crawling is the first measure that search engines take before indexing content in virtually any form–videos, text, images, webpages, etc..The content may constitute newly uploaded content to the internet or content that features updates or changes to its material. These robots, also known as crawlers or bots, record the information along with its links. Once the material has been crawled, it can be stored in a massive URL database. It’s this database that generates internet search results. Indexing After the bots crawl content, it can be indexed in the database and arranged in terms of its relevance. If internet content has not been crawled or indexed, it is unlikely to appear in the search results when someone makes a query no matter how relevant that content may be. After the content has been crawled, each of its words is indexed. The search engines also pinpoint where words are located on the crawled pages. During the indexing process, the search engine compares the content to other content with similar ‘words’ and decides how to organize it within its index. Ranking Ranking is a complex process that is dependent on search engine algorithms. When a searcher makes a query on Google looking for anything from 19th century British landscape painters to New York City plumbers, the search engine will generate a list of good matches to that query. How these matches appear in the list relates to its rank. The search engine lists what it ‘thinks’ are the best answers to the query early in its search results. Google and other search engines rely on algorithms to interpret the searcher’s query, identify the websites and pages in its index that are related to the request, and it then ranks them in terms of relevance in its presented search results list. What’s important to search engines is to provide searchers with the most relevant matches to their queries as possible. Website operators, in turn, use search engine optimization to give their pages a higher rank. References

Sabbath in Christianity is the day of rest and service to God. The idea of the Sabbath in Christianity comes directly from the idea of the Sabbath (or Shabbat) in Judaism. In fact, the word Sabbath itself comes from the Hebrew word Shabbat. Like the Jewish Sabbath (Shabbat), the Sabbath in Christianity comes from the Genesis story of Creation. But unlike Jews, most Christians have Sabbath on Sunday, not Saturday. They also rest, but not the same way as Jews. The exact way depends on the church denomination. Differing views Most Christians honor the Sabbath on Sunday to remember the Resurrection of Jesus on the first day of the week on the Jewish calendar. They say that there is an analogy between the obligation of the Christian day of worship and the Sabbath-day ordinance. These two rules are not literally identical though. They say that this ordinance is no longer valid, because God has replaced his old creation by a new one. For this reason, the obligation to keep the Sabbath is not the same for Christians as for Jews. They say there are examples in the New Testament, and in other writings surviving from the first few centuries. Some conservative Christians are "Sabbatarians". Most of these follow the Reformed traditions. Sabbatarians think the first day of the week or Lord's Day is the new Sabbath. This is because the 4th commandment has never been revoked and Sabbath-keeping is in any case a creation ordinance. Still others believe that the Sabbath remains as a day of rest on the Saturday, reserving Sunday as a day of worship. In reference to Acts 20:7, the disciples came together on the first day of the week (Sunday) to break bread and to hear the preaching of the apostle Paul. This is not the first time Christians assembled together on a Sunday; Jesus appeared to the Christians on the "first day of the week" while they were in hiding. One can maintain this argument in that Jesus himself maintained the Sabbath, although not within the restrictions that were mandated by Jewish traditions; the Pharisees often tried Jesus by asking him if certain tasks were acceptable according to the Law. This would seem to show that while the Sabbath was still of importance to the Jews, Sunday was a separate day for worship and teaching from Scriptures. The Seventh-day Adventists and other churches disagree with some of these views. They argue that the custom of meeting for worship on Sunday originated in paganism, specifically Sol Invictus and Mithraism (in which sun god worship took place on Sunday). This is therefore an explicit rejection of the commandment to keep the seventh day holy. Instead, they keep Saturday as the Sabbath as a memorial to God's work of creation believing that none of the Ten Commandments can ever be destroyed. Seventh-day Sabbatarians claim that the seventh day Sabbath was kept by the majority of Christian groups until the 2nd and 3rd century, by most until the 4th and 5th century, and a few thereafter, but because of opposition to Judaism after the Jewish-Roman wars, the original custom was gradually replaced by Sunday as the day of worship. The history of these changes is certainly not altogether lost regardless of any belief in a suppression of the facts by a conspiracy of the pagans of the Roman Empire and the clergy of the Catholic Church. Jews had come to be hated in the Roman Empire after the Jewish-Roman wars. This led to the criminalization of the Jewish Sabbath. Hatred of Jews is apparent in the Council of Laodicea (4th Century AD) where Canon 37–38 states: "It is not lawful to receive portions sent from the feasts of Jews or heretics, nor to feast together with them." and "It is not lawful to receive unleavened bread from the Jews, nor to be partakers of their impiety." In keeping with this rejection of the Jews, this Roman council also criminalized the Jewish Sabbath as can be seen in Canon 29 of the Council Laodicea: "Christians must not Judaize by resting on the Sabbath, but must work on that day, rather honoring the Lord's Day; and, if they can, resting then as Christians. But if any shall be found to be judaizers, let them be excommunicated from Christ." In the Gospel of Mark 2:28 Jesus says 'the Son of Man is lord even of the sabbath'. References Liturgical calendar

Statistics is a branch of applied mathematics that deals with collecting, organising, analysing, reading and presenting data. Descriptive statistics make summaries of data. Inferential statistics makes predictions. Statistics helps in the study of many other fields, such as science, medicine, economics, psychology, politics and marketing. Someone who works in statistics is called a statistician. In addition to being the name of a field of study, the word "statistics" can also mean numbers that are used to describe data or relationships. History The first known statistics are census data. The Babylonians did a census around 3500 BC, the Egyptians around 2500 BC, and the Ancient Chinese around 1000 BC. Starting in the 16th century mathematicians such as Gerolamo Cardano developed probability theory, which made statistics a science. Since then, people have collected and studied statistics on many things. Trees, starfish, stars, rocks, words, almost anything that can be counted has been a subject of statistics. Collecting data Before we can describe the world with statistics, we must collect data. The data that we collect in statistics are called measurements. After we collect data, we use one or more numbers to describe each observation or measurement. For example, suppose that we want to find out how popular a certain TV show is. We can pick a group of people (called a sample) out of the total population of viewers. Then we ask each viewer in the sample how often they watch the show. The sample is data that one can see, and the population is data that one cannot see (assuming that not every viewer in the population are asked). For another example, if we want to know whether a certain drug can help lower blood pressure, we could give the drug to people for some time and measure their blood pressure before and after. Descriptive and inferential statistics Numbers that describe the data one can see are called descriptive statistics. Numbers that make predictions about the data one cannot see are called inferential statistics. Descriptive statistics involves using numbers to describe features of data. For example, the average height of women in the United States is a descriptive statistic: it describes a feature (average height) of a population (women in the United States). Once the results have been summarized and described, they can be used for prediction. This is called inferential statistics. As an example, the size of an animal is dependent on many factors. Some of these factors are controlled by the environment, but others are by inheritance. A biologist might therefore make a model that says that there is a high probability that the offspring will be small in size—if the parents were small in size. This model probably allows to predict the size in better ways than by just guessing at random. Testing whether a certain drug can be used to cure a certain condition or disease is usually done by comparing the results of people who are given the drug against those who are given a placebo. Methods Most often, we collect statistical data by doing surveys or experiments. For example, an opinion poll is one kind of survey. We pick a small number of people and ask them questions. Then, we use their answers as the data. The choice of which individuals to take for a survey or data collection is important, as it directly influences the statistics. When the statistics are done, it can no longer be determined which individuals are taken. Suppose we want to measure the water quality of a big lake. If we take samples next to the waste drain, we will get different results than if the samples are taken in a far-away and hard-to-reach spot of the lake. There are two kinds of problems which are commonly found when taking samples: If there are many samples, the samples will likely be very close to what they are in the real population. If there are very few samples, however, they might be very different from what they are in the real population. This error is called a chance error (see also Errors and residuals in statistics). The individuals for the samples need to be chosen carefully. Usually, they will be chosen randomly. If this is not the case, the samples might be very different from what they really are in the total population. This is true even if a great number of samples is taken. This kind of error is called bias. Errors We can reduce chance errors by taking a larger sample, and we can avoid some bias by choosing randomly. However, sometimes large random samples are hard to take. And bias can happen if different people are not asked, or refuse to answer our questions, or if they know they are getting a fake treatment. These problems can be hard to fix. See standard error for more. Descriptive statistics Finding the middle of the data The middle of the data is called an average. The average tells us about a typical individual in the population. There are three kinds of average that are often used: the mean, the median and the mode. The examples below use this sample data: Mean The formula for the mean is Where are the data and is the population size (see also Sigma Notation). This means that one calculates the mean by adding up all the values, and then divide by the number of values. For the example above, the mean is: The problem with the mean is that it does not tell anything about how the values are distributed. Values that are very large or very small change the mean a lot. In statistics, these extreme values might be errors of measurement, but sometimes the population really does contain these values. For example, if there are 10 people in a room who make $10 per day and 1 who makes $1,000,000 per day. The mean of the data is $90,918 per day. Even though it is the average amount, the mean in this case is not the amount any single person makes, and thus is not very useful for some purposes. The mean described above is the "arithmetic mean". Other kinds are useful for some purposes. Median The median is the middle item of the data. For a given data , this is sometimes written as . To find the median, we sort the data from the smallest number to the largest number, and then choose the number in the middle. If there is an even number of data, there will not be a number right in the middle, so we choose the two middle ones and calculate their mean. In our example above, there are 10 items of data, the two middle ones are "57" and "64", so the median is (57+64)/2 = 60.5. As another example, like the income example presented for the mean, consider a room with 10 people who have incomes of $10, $20, $20, $40, $50, $60, $90, $90, $100, and $1,000,000. Here, the median is $55, because $55 is the average of the two middle numbers, $50 and $60. If the extreme value of $1,000,000 is ignored, the mean is $53. In this case, the median is close to the value obtained when the extreme value is thrown out. The median solves the problem of extreme values as described in the definition of mean above. Mode The mode is the most frequent item of data. For example, the most common letter in English is the letter "e". We would say that "e" is the mode of the distribution of the letters. As another example, if there are 10 people in a room with incomes of $10, $20, $20, $40, $50, $60, $90, $90, $90, $100, and $1,000,000, then the mode is $90, because $90 occurs three times and all other values occur fewer than three times. There can be more than one mode. For example, if there are 10 people in a room with incomes of $10, $20, $20, $20, $50, $60, $90, $90, $90, $100, and $1,000,000, the modes are $20 and $90. This is bi-modal, or has two modes. Bi-modality is very common, and it often indicates that the data is the combination of two different groups. For instance, the average height of all adults in the U.S. has a bi-modal distribution. This is because males and females have separate average heights of 1.763 m (5 ft 9 + 1⁄2 in) for men and 1.622 m (5 ft 4 in) for women. These peaks are apparent when both groups are combined. The mode is the only form of average that can be used for data that can not be put in order. Finding the spread of the data Another thing we can say about a set of data is how spread out it is. A common way to describe the spread of a set of data is the standard deviation. If the standard deviation of a set of data is small, then most of the data is very close to the average. If the standard deviation is large, though, then a lot of the data is very different from the average. The standard deviation of a sample is generally different from the standard deviation of its originating population . Because of that, we write for population standard deviation, and for sample standard deviation. If the data follows the common pattern called the normal distribution, then it is very useful to know the standard deviation. If the data follows this pattern (we would say the data is normally distributed), about 68 of every 100 pieces of data will be off the average by less than the standard deviation. Not only that, but about 95 of every 100 measurements will be off the average by less than two times the standard deviation, and about 997 in 1000 will be closer to the average by less than three standard deviations. Other descriptive statistics We also can use statistics to find out that some percent, percentile, number, or fraction of people or things in a group do something or fit in a certain category. For example, social scientists used statistics to find out that 49% of people in the world are males. Related software In order to support statisticians, many statistical software have been developed: MATLAB R SAS Institute SPSS (made by IBM) References Other websites Statistics

Speed is the distance of a moving object in a given amount of time. Speed is a measure of how fast something is moving. The average speed of an object in a certain time is the distance the object travelled divided by the time. Speed is also the distance covered by an object per unit time. Finding speed To find speed , where is the distance and is the time that has gone by. Units of measurement for speed There are many units of measurement for speed. For example, an object's speed can be measured in miles per hour (mph), kilometers per hour (km/h) meters per second (m/s), which is the SI-unit for speed. Changing speed When an object changes speed, it gets faster or slower. If the speed of the object increases, it is called acceleration. If the object gets slower, and the speed decreases, it is called deceleration, or negative acceleration. Related pages Velocity Momentum Quantum mechanics Metric system Other websites Measurement Physical quantity

A server log records what is happening on a server at any time. For example, an HTTP server runs a web site. internet Software Servers de:Logdatei

In net jargon, a server is a computer that serves many kinds of information to a user or client machine. Usually a server will only do a few things for many clients. Every type of thing a server does is called a service. Services are used by other computers that are called clients. The relationship between client and server is called a client-server relationship. For example, Wikipedia has web servers which have a service for sending web pages over the Internet. Your client computer talks to Wikipedia's web page service to get web pages for you. A server can also host internet games, share files, and give access to peripheral equipment such as printers. In simple words, the individual computers are connected to some powerful computers called servers. These store files and information in the form of website. With an Internet connection, different users anywhere in the world can access these files. For servers and clients to talk to each other, they need to be connected to a network. They need to use the same communication protocol, a set way for machines to talk to other machines. It is like a language. For example, the Wikipedia server runs the HTTP to send web sites to your computer, and your computer uses the HTTP Protocol to ask Wikipedia for pages. Overview Usually, servers are specially made to be more powerful and reliable. They are usually more expensive than normal computers. Sometimes, servers can be clustered, which means many servers are working together to do one service. The server might slow down if there are too many people accessing the server at the same time, resulting in a high load. An overloaded server might also shut itself down automatically. In a peer-to-peer system, every computer is both a client and a server to the others. This is commonly put into file sharing and VOIP. However, this can help in attempts at piracy. Typical server operating systems are Linux, FreeBSD, NetBSD, and OpenBSD. Unlike other computers, a server often has no monitor, keyboard, or mouse. When a server doesn't have to do very much, server software can run on a computer that is also doing other things. Web server A web server is a type of server that is used to host websites. Examples of web server software include Apache or IIS. A web server can host one, or many, websites. The default port for a web server to listen to is port 80 (HTTP) or 443 (HTTPS). Some web servers do other things than just serving a web page. For example, they may have something called SSI that makes building a website easier. Web servers use services like CGI to let software on the server make web pages. Some of the programming languages that can use CGI are scripting languages like Perl, Python, PHP, or ASP. Some are compiled languages like C++ or Java. Reference Related pages File server Reference Internet Servers Computer science

A simile is a figure of speech that compares two different things, usually by using the words 'like' or 'as'. It is used to make a direct and clear comparison between two things .Similes may be confused with metaphors, which do the same kind of thing. Similes use comparisons, with the words 'like' or 'as'. Metaphors use indirect comparisons, without the words 'like' or 'as'. Similes: Like a hungry wolf, he ate the food. A dragonfly is like a plane: they both fly and cannot close their wings. He fought like a lion. The color yellow is like walking into a surprise birthday party. The other team's quarterback is as big as a redwood tree Kingda Ka is as green as a pine tree Other websites "On substantiation through transitive relations" is an old manuscript written by the Arabic scholar Sayf al-Din al-Amidi. He talks about similes. Words Figures of speech

In politics, a state is a country which has control over a geographic area or territory. States have three main features: Control over a geographic area, or territory A people, the population of the state. Institutions which have the power to make laws. There are different forms of government a state may have, for example a republic or a monarchy. Sometimes states form their own countries. At other times many states work together to form a country (like the United States). Most states also have armed forces, civil service, law and police. Different definitions The definition above is very broad. It is based on ideas by Georg Jellinek (1851-1911). Other people had other ideas: Max Weber (1864-1920) had another definition: According to him, a state is a community of people which has "the monopoly to legitimately use physical force within a well-defined area". Another definition is form political science: A state is a system of public institutions which are there to regulate the issues of a society. Some philiospohers, such as Aristotle, Rousseau and Hegel had a moralistic view: In their opinion, a state arises when individuals reach their goals and that of society. According to Hegel, the state is the reason God came into the world; it is the power of reason. This reason manifests as His will. Because of the different definitions, there's no universally accepted definition of state. The one given at the start of the article is now part of international law. History Early states The earliest states were just human settlements. A group of farmers and merchants working together could be 'states' since people can control them and protect them. More organized states could be monarchies such as early Egypt under the Pharaoh. Following this were larger more military-based states such as the Babylonian Empire or Roman Empire. The most famous early states, however, were the Ancient Greek city-states. Some of them had democracy. From military to modern state When the military-based state, the Roman Empire, fell, lots of little states were made and each was also military-based and controlled by a king. These states did not often work together and war raged. However, once people within the state itself started fighting (what's called a Civil war), the kings had to make peace and start parliaments. Modern states Modern states soon started in the late 15th century. The main states in Europe were: England under the Tudors Spain under the Habsburg France under the Bourbons Russia under Catherine the Great and Alexander II of Russia These states all tried to improve their politics and economy and became more and more like the states today. They formed proper boundaries for their lands and worked with power within the state itself more, such as the Church or the nobility. They made armies, tax systems and embassies all to help make them more powerful and stable. Different types of state Types of state can be separated into two categories: democracy and dictatorship. However, just because a group of states are all democratic does not mean that they follow the same rules. Iran, Pakistan, France, Germany and the United States of America are all states. Each of them sees itself as a democracy. Each of them however has a different idea of what democracy really means. Different states of the same 'category' can also function differently. For example, two democratic states may be quite different if one has a well-trained police or army while the other does not. Therefore, the word 'state' only tells us what type of government that state follows (democratic or dictatorship) and does not tell us about the country itself. Sub-categories of state There are lots of sub-types of state branching off from democracy and dictatorship. The main ones are Pluralism, Marxism and Institutionalism. Pluralism Pluralism has been very popular in the United States. It shows the state as a neutral place for settling arguments between other states. Pluralism tells us that all people are not equal, but still allows each group of people to tell the state what to do. This type of state is called a polyarchy. Also in a pluralist state, politics, the military and the economy are all united and work together. This means that all power in the state is 'diffused' across the people who live there. Marxism Marxism is an ideology advocating for the rights of workers and labourers of society. It was started by Karl Marx and Friedrich Engels. Marxism rejects the idea that a state is there to protect business interest, and is definitely not a neutral place for settling arguments. The main job of a Marxist state is to protect the labour and financial situation of the peasant classes. With such reforms, a Marxist state focuses on collectivising resources and creating a planned economy to ensure the well-being of the workers. Both Marxist and Pluralist states have to react to the activities of groups of people in the state itself. Institutionalist states do not see themselves as 'instruments' to be controlled, they are more just geographical areas. In this area, the people just form groups themselves. An institutionalist state can be made up of both Marxist and Pluralist people, both which have the power to control themselves and not influence the other parties of the state. Anarchism Anarchism is when a group of people have complete freedom and do not believe in having a state at all. Anarchists are a lot like Marxists, since they do not believe that all people are equal, but they believe (opposite to Marxists) that a country can work without any organizations in it. Law and order are not necessary. Anarchists (such as Bakunin and Kropotkin in the 19th century), often want a form of Marxism but ignoring some of their rules. They want workers to manage themselves and simply get paid for what they do, rather than getting paid in wages. Related pages Country Sovereign state International relations List of sovereign states Montevideo Convention Nation Social contract U.S. state Unitary state Province Political economy Constitutional economics Local government References Social sciences International law

A stream is a natural flow of water moving across country between banks. It is smaller than a river. The primary meaning of stream is a body of water, confined within a bed and banks, and detectably flowing. Synonyms or related words include river, creek, tributary, run, branch, brook, bourne, wash, and fork. Navigable streams are sometimes called waterways, though the term may apply to any size of permanent and natural water feature except oceans. In the United States, an intermittent stream is one that only flows for part of the year and is marked on topographic maps with a line of blue dashes and dots. In desert areas of the American Southwest, this also includes washes, which only flow after thunderstorms or other significant rains. A blue-line stream is one which flows for most or all of the year and is marked on topographic maps with a solid blue line. In Australia, an intermittent stream is usually called a creek, and marked on topographic maps with a solid blue line. Generally, streams that form only during and immediately after precipitation are termed ephemeral streams. Streams in geographic terms are awarded order designations. A stream of the first order is a blue-line stream which does not have any other blue-line stream feeding into it. A stream of the second order is one which is formed by the joining of two or more blue-line streams. A third-order stream is one below the confluence of two or more second-order streams; a fourth-order stream is formed by the confluence of at least two third-order streams, and so forth. Typically, streams are said to have a particular profile, beginning with steep gradients, no flood plain, and little shifting of channels, eventually evolving into streams with low gradients, wide flood plains, and extensive meanders. The initial stage is sometimes termed a "young" stream, and the later state a "mature" or "old" stream. However, a stream may meander for some distance before falling into a "young" stream condition. The gradient of a stream is a critical factor in determining its character, and is entirely determined by its base level of erosion. The base level of erosion is the point at which the stream either enters the ocean, a lake or pond, or enters a stretch in which it has a much lower gradient, and may be specifically applied to any particular stretch of a stream. In geologic terms, the stream will erode down through its bed to achieve the base level of erosion throughout its course. If this base level is low, then the stream will rapidly cut through underlying strata and have a steep gradient, and if the base level is relatively high, then the stream will form a flood plain and meanders. When a stream flows over an especially resistant stratum and forms a waterfall or cascade, or the same results because for some reason the base level of erosion suddenly drops, perhaps as a result of a fault, the resulting sudden change in stream elevation is called a nickpoint. The stream, of course, expends kinetic energy in "trying" to eliminate the nickpoint. Meanders are looping changes of direction of a stream. These may be somewhat sine-wave in form. Typically, over time, the meanders don't disappear but gradually migrate downstream. However, if some resistant material slows or stops the downstream movement of a meander, a stream may erode through the neck between two legs of a meander to become temporarily straighter, leaving behind an arc-shaped body of water termed an oxbow lake or bayou. A flood may also result in a meander being cut through in this way. The point of origin of a stream is often called the headwaters or source. The entire basin drained by the stream is termed the watershed. Every watershed is made up of smaller watersheds, while most watersheds are parts of larger watersheds. For instance, the Continental Divide in North America divides the Atlantic Ocean watershed from the Pacific Ocean watershed, but the Atlantic Ocean watershed may be first divided into the Atlantic Ocean drainage and the Gulf of Mexico drainage. This delineation within the United States is termed the Eastern Divide. The Gulf of Mexico watershed may be divided into Mississippi River basin and a number of smaller watersheds, such as the Tombigbee River watershed. The Mississippi River watershed includes the Ohio River watershed, which in turn includes the Kentucky River watershed, and so forth. The point at which a stream empties into an ocean or other large body of relatively level water is termed the mouth. There may often be an estuary or delta at the mouth. Some streams flow underground through unconsolidated sediments or through caves. Especially with caves, a stream may flow aboveground for part of its course, and underground for part of its course. When a stream emerges from an underground course, it is termed a spring. The study of streams and waterways in general is known as surface hydrology and is important in environmental geography or environmental geology. Related pages waterfall river waterway lake marsh swamp ocean spring water

The Solar System is the Sun and all the objects that orbit around it. The Sun is orbited by planets, asteroids, comets and other things. The Solar System is about 4.6 billion years old. It formed by gravity in a large molecular cloud. Most of this matter came together in the center, and the rest flattened into an orbiting disk that became the Solar System. It is thought that almost all stars form by this process. The Sun is a star. It makes up 99.9% of the Solar System's mass. This means that it has strong gravity. The other objects are pulled into orbit around the Sun. The Sun is mostly made out of hydrogen, and some helium and higher elements. There are eight planets in the Solar System. From closest to farthest from the Sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first four planets are called terrestrial planets. They are mostly made of rock and metal, and they are mostly solid. The last four planets are called gas giants. This is because they are much larger than other planets and are mostly made of gas. Titan, one of Saturn’s moons, is the only moon in the solar system to have an Atmosphere. The Solar System also contains other things. There are asteroid belts, mostly between Mars and Jupiter. Further out than Neptune, there is the Kuiper belt and the scattered disc. These areas have dwarf planets, including Pluto, Makemake, Haumea, Ceres and Eris. There are thousands of very small objects in these areas. There are also comets, centaurs, and interplanetary dust. In Ancient Greece, Aristarchus of Samos proposed the heliocentric model of the Solar System, where the Sun, is at the center of the known universe. He is sometimes known as the "Greek Copernicus". Six of the planets and three of the dwarf planets are orbited by moons. There are about 200 moons in the Solar System. Mercury and Venus have no moons, and Jupiter and Saturn have the largest number of moons. The largest moon is Ganymede which is a moon of Jupiter. Furthermore, planetary dust orbits the gas giants. Many other systems like the Solar System have been found. Each of the billions of stars in the Milky Way galaxy might have a planetary system. Evolution of the Solar System The formation and evolution of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the centre, forming the Sun, while the rest flattened into a protoplanetary disk of loose dust, out of which the planets, moons, asteroids, and other Solar System bodies formed. This model, known as the nebular hypothesis, was developed in the 18th (1700s) century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. It has been adjusted by scientific disciplines such as astronomy, physics, geology, and planetary science. As our knowledge of space has grown, the models have been changed to account for the new observations. The Solar System has evolved considerably since its initial formation. Many moons have formed from circling discs of gas and dust around their parent planets, while other moons are believed to have formed and were later captured by their planets. Still others, as the Earth's Moon, may be the result of giant collisions. Many collisions between bodies have occurred, and have been important to the evolution of the Solar System. In the early stages, the positions of the planets sometimes shifted, and planets have switched places. This planetary migration is thought to have been responsible for much of the Solar System's early evolution. Earth's orbit The Earth's orbit around the Sun is nearly a perfect circle, but when mapped it is found that the Earth moves around the Sun in a very slightly oval shaped orbit, called an elliptical orbit. The other planets in the Solar System also orbits the Sun in slightly elliptical orbits. Mercury has a more elliptical orbit than the others, and some of the smaller objects orbit the Sun in very eccentric orbits. Discovery and exploration For thousands of years, people had no need for a name for the "Solar System". They thought the Earth stayed still at the center of everything (geocentrism). Although the Greek philosopher Aristarchus of Samos suggested that there was a special order in the sky, Nicolaus Copernicus was the first to develop a mathematical system that described what we now call the "solar system". This was called a new "system of the world". In the 17th century, Galileo Galilei, Johannes Kepler and Isaac Newton began helping people understand physics more clearly. People began to accept the idea that the Earth is a planet and moves around the Sun, and that the planets are worlds with the same physical laws that control Earth. More recently, telescopes and space probes have led to discoveries of mountains and craters, and seasonal meteorological phenomena such as clouds, dust storms and ice caps on the other planets. The eight planets In their order from the Sun: Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune The planets are the biggest objects that go around the Sun. It took people many years of using telescopes to find the objects that were farthest away. New planets might still be found, and more small objects are found every year. Most of the planets have moons that orbit around them just as the planets orbit the Sun. There are at least 173 of these moons in the solar system. Dwarf planets Pluto was discovered by American astronomer Clyde Tombaugh and was declared the 9th planet of the solar system in 1930. This all changed on August 24, 2006, when the International Astronomical Union (IAU) gave a correct definition to the word "planet" for the first time. By this definition, Pluto was not a planet anymore due to its irregular orbit and size. Eris was more massive than Pluto. It became a "dwarf planet" along with Eris and many others. After this, Pluto was put on the list of minor planets and was downgraded in 2006 by astronomer Michael E Brown. Instead they defined a new category of dwarf planet, into which Pluto did fit, along with some others. These small planets are sometimes called plutinos. Pluto Ceres Haumea Eris Makemake Structure There are a few main parts of the Solar System. Here they are in order from the Sun, with the planets numbered, and the dwarf planets marked with the letters a - e. Inner solar system The first four planets closest to the Sun are called the inner planets. They are small and dense terrestrial planets, with solid surfaces. They are made up of mostly rock and metal with a distinct internal structure and a similar size. Three also have an atmosphere. The study of the four planets gives information about geology outside the Earth. Most asteroids are also often counted with the inner planets Terrestrial planets region contains the four planets closest to the sun, all are rocky planets (1) Mercury (2) Venus (3) Earth (4) Mars Asteroid belt region contains; (a) Ceres (the only dwarf planet in this region) Asteroids Outer solar system Gas giant planets region contains; (5) Jupiter (6) Saturn (7) Uranus (8) Neptune Trans-Neptune region Kuiper belt region contains; (b) Pluto (c) Haumea (d) Makemake Kuiper belt objects and possibly other dwarf planets short-period comets Scattered disc region contains; (e) Eris Scattered disk objects and possibly other dwarf planets Oort Cloud The Oort cloud is separate from the trans-Neptune region, and much farther out. It contains the long-period comets. Ecliptic plane The plane of the ecliptic is defined by the Earth's orbit around the Sun. All of the planets orbit the Sun roughly around this same orbital plane. The farther away from this plane a planet orbits, the more inclined is its orbit to the ecliptic. If you could look at the solar system "edge on" then all the planets would be orbiting more or less in the plane of the ecliptic. References More reading Other websites Views of the Solar System Your Weight on Other Worlds Solar System Citizendium The Planets in the Solar System

Saturn is the sixth planet from the Sun located in the Solar System. It is the second largest planet in the Solar System, after Jupiter. Saturn is one of the four gas giant planets, along with Jupiter, Uranus, and Neptune. Saturn is the English transliteration from the Latin word Saturnus, in Roman religion, the god of sowing or seed. The Romans equated him with the Greek agricultural deity Kronos. Saturn was named after the Roman god Saturnus (called Kronos in Greek mythology). Saturn's symbol is ♄ which is the symbol of Saturnus' sickle. Inside Saturn is probably a core of iron, nickel, silicon and oxygen compounds, surrounded by a deep layer of metallic hydrogen, then a layer of liquid hydrogen and liquid helium and finally, an outer gaseous layer. Saturn has 82 known moons orbiting the planet. 53 are officially named and 29 are waiting to be named. The largest moon is Titan, which is larger in volume than the planet Mercury. Titan is the second-largest moon in the Solar System. The largest moon is Jupiter's moon, Ganymede. There is also a very large system of rings around Saturn. These rings are made of ice with smaller amounts of rocks and dust. Some people believe that the rings were caused by a moon impact or other event. Saturn is about 1,433,000,000 km (870,000,000 mi) on average from the Sun. Saturn takes 29.6 Earth years to revolve around the Sun. Physical features Saturn is an oblate spheroid, meaning that it is flattened at the poles, and it swells out around its equator. The planet's equatorial diameter is , while its polar diameter (the distance from the north pole to the south pole) is ; a 9% difference. Saturn has a flattened shape due to its very fast rotation, once every 10.8 hours. Saturn is the only planet in the Solar System that is less dense than water. Even though the planet's core is very dense, it has a gaseous atmosphere, so the average specific density of the planet is 0.69 g/cm3. This means if Saturn could be placed in a large pool of water, it would float. Atmosphere The outer part of Saturn's atmosphere is made up of about 96% hydrogen, 3% helium, 0.4% methane and 0.01% ammonia. There are also very small amounts of acetylene, ethane and phosphine. Saturn's clouds show a banded pattern, like the cloud bands seen on Jupiter. Saturn's clouds are much fainter and the bands are wider at the equator. Saturn's lowest cloud layer is made up of water ice, and is about thick. The temperature here is quite low, at 250 K (-10°F, -23°C). However scientists do not agree about this. The layer above, about thick, is made up of ammonium hydrosulfide ice, and above that is a layer of ammonia ice clouds thick. The highest layer is made up of hydrogen and helium gases, which extends between and above the water cloud tops. Auroras are also known to form in Saturn in the mesosphere. The temperature at Saturn's cloud tops is extremely low, at 98 K (-283 °F, -175 °C). The temperatures in the inner layers are much higher than the outside layers because of the heat produced by Saturn's interior. Saturn's winds are some of the fastest in the Solar System, reaching 1,800 km/h (1,118 mph), ten times faster than winds on Earth. Storms and spots Saturn's atmosphere is also known to form oval shaped clouds, similar to the clearer spots seen in Jupiter. These oval spots are cyclonic storms, the same as cyclones seen on Earth. In 1990, the Hubble Space Telescope found a very large white cloud near Saturn's equator. Storms like the one in 1990 were known as Great White Spots. These unique storms only exist for a short time and only happen about every 30 Earth years, at the time of the summer solstice in the Northern Hemisphere. Great White Spots were also found in 1876, 1903, 1933, and 1960. If this cycle continues, another storm will form in about 2020. The Voyager 1 spacecraft found a hexagonal cloud pattern near Saturn's north pole at about 78°N. The Cassini−Huygens probe later confirmed it in 2006. Unlike the north pole, the south pole does not show any hexagonal cloud feature. The probe also discovered a hurricane-like storm locked to the south pole that clearly showed an eyewall. Until this discovery, eyewalls had only been seen on Earth. Interior Saturn's interior is similar to Jupiter's interior. It has a small rocky core about the size of the Earth at its center. It is very hot; its temperature reaches 15,000 K (). Saturn is so hot that it gives out more heat energy into space than it receives from the Sun. Above it is a thicker layer of metallic hydrogen, about deep. Above that layer is a region of liquid hydrogen and helium. The core is heavy, with about 9 to 22 times more mass than the Earth's core. Magnetic field Saturn has a natural magnetic field that is weaker than Jupiter's. Like the Earth's, Saturn's field is a magnetic dipole. Saturn's field is unique in that it is perfectly symmetrical, unlike any other known planet. This means the field is exactly in line with the planet's axis. Saturn generates radio waves, but they are too weak to be detected from Earth. The moon Titan orbits in the outer part of Saturn's magnetic field and gives out plasma to the field from the ionised particles in Titan's atmosphere. Rotation and orbit Saturn's average distance from the Sun is over 1,400,000,000 km (869,000,000 mi), about nine times the distance from the Earth to the Sun. It takes 10,759 days, or about 29.8 years, for Saturn to orbit around the Sun. This is known as Saturn's orbital period. Voyager 1 measured Saturn's rotation as being 10 hours 14 minutes at the equator, 10 hours 40 minutes closer to the poles, and 10 hours 39 minutes 24 seconds for the planet's interior. This is known as its rotational period. Cassini measured the rotation of Saturn as being 10 hours 45 minutes 45 seconds ± 36 seconds. That is about six minutes, or one percent, longer than the radio rotational period measured by the Voyager 1 and Voyager 2 spacecraft, which flew by Saturn in 1980 and 1981. Saturn's rotational period is calculated by the rotation speed of radio waves released by the planet. The Cassini−Huygens spacecraft discovered that the radio waves slowed down, suggesting that the rotational period increased. Since the scientists do not think Saturn's rotation is actually slowing down, the explanation may lie in the magnetic field that causes the radio waves. Planetary rings Saturn is best known for its planetary rings which are easy to see with a telescope. There are seven named rings; A, B, C, D, E, F, and G rings. They were named in the order they were discovered, which is different to their order from the planet. From the planet the rings are: D, C, B, A, F, G and E. Scientists believe that the rings are material left after a moon broke apart. A new idea says that it was a very large moon, most of which crashed into the planet. This left a large amount of ice to form the rings, and also some of the moons, like Enceladus, which are thought to be made of ice. History The rings were first discovered by Galileo Galilei in 1610, using his telescope. They did not look like rings to Galileo, so he called them "handles". He thought that Saturn was three separate planets that almost touched one another. In 1612, when the rings were facing edge on with the Earth, the rings disappeared, then reappeared again in 1613, further confusing Galileo. In 1655, Christiaan Huygens was the first person to recognise Saturn was surrounded by rings. Using a much more powerful telescope than Galilei's, he noted Saturn "is surrounded by a thin, flat, ring, nowhere touching...". In 1675, Giovanni Domenico Cassini discovered that the planet's rings were in fact made of smaller ringlets with gaps. The largest ring gap was later named the Cassini Division. In 1859, James Clerk Maxwell showed that the rings cannot be solid, but are made of small particles, each orbiting Saturn on their own, otherwise, it would become unstable or break apart. James Keeler studied the rings using a spectroscope in 1895 which proved Maxwell's theory. Physical features The rings range from to above the planet's equator. While the equatorial circumference of Saturn is 378,675 km (235,298 miles).As proved by Maxwell, even though the rings appear to be solid and unbroken when viewed from above, the rings are made of small particles of rock and ice. They are only about thick; made of silica rock, iron oxide and ice particles. The smallest particles are only specks of dust while the largest are the size of a house. The C and D rings also seem to have a "wave" in them, like waves in water. These large waves are high, but only moving slowly at about each day. Some scientists believe that the wave is caused by Saturn's moons. Another idea is the waves were made by a comet hitting Saturn in 1983 or 1984. The largest gaps in the rings are the Cassini Division and the Encke Division, both visible from the Earth. The Cassini Division is the largest, measuring wide. However, when the Voyager spacecrafts visited Saturn in 1980, they discovered that the rings are a complex structure, made out of thousands of thin gaps and ringlets. Scientists believe this is caused by the gravitational force of some of Saturn's moons. The tiny moon Pan orbits inside Saturn's rings, creating a gap within the rings. Other ringlets keep their structure due to the gravitational force of shepherd satellites, such as Prometheus and Pandora. Other gaps form due to the gravitational force of a large moon farther away. The moon Mimas is responsible for clearing away the Cassini gap. Recent data from the Cassini spacecraft has shown that the rings have their own atmosphere, free from the planet's atmosphere. The rings' atmosphere is made of oxygen gas, and it is produced when the Sun's ultraviolet light breaks up the water ice in the rings. Chemical reaction also occurs between the ultraviolet light and the water molecules, creating hydrogen gas. The oxygen and hydrogen atmospheres around the rings are very widely spaced. As well as oxygen and hydrogen gas, the rings have a thin atmosphere made of hydroxide. This anion was discovered by the Hubble Space Telescope. Spokes The Voyager space probe discovered features shaped like rays, called spokes. These were also seen later by the Hubble telescope. The Cassini probe photographed the spokes in 2005. They are seen as dark when under sunlight, and appear light when against the unlit side. At first it was thought the spokes were made of microscopic dust particles but new evidence shows that they are made of ice. They rotate at the same time with the planet's magnetosphere, therefore, it is believed that they have a connection with electromagnetism. However, what causes the spokes to form is still unknown. They appear to be seasonal, disappearing during solstice and appearing again during equinox. Moons Saturn has 53 named moons, and another 29 which are still being studied. Many of the moons are very small: 33 are less than in diameter and 13 moons are less than . Seven moons are large enough to be a near perfect sphere caused by their own gravitation. These moons are Titan, Rhea, Iapetus, Dione, Tethys, Enceladus and Mimas. Titan is the largest moon, larger than the planet Mercury, and it is the only moon in the Solar System to have a thick, dense atmosphere. Hyperion and Phoebe are the next largest moons, larger than in diameter. In December 2004 and January 2005 a man-made satellite called the Cassini−Huygens probe took lots of close photos of Titan. One part of this satellite, known as the Huygens probe, then landed on Titan. Named after the Dutch astronomer Christiaan Huygens, it was the first spacecraft to land in the outer Solar System. The probe was designed to float in case it landed in liquid. Enceladus, the sixth largest moon, is about in diameter. It is one of the few outer solar system objects that shows volcanic activity. In 2011, scientists discovered an electric link between Saturn and Enceladus. This is caused by ionised particles from volcanos on the small moon interacting with Saturn's magnetic fields. Similar interactions cause the northern lights on Earth. Exploration Saturn was first explored by the Pioneer 11 spacecraft in September 1979. It flew as close as above the planet's cloud tops. It took photographs of the planet and a few of its moons, but were low in resolution. It discovered a new, thin ring called the F ring. It also discovered that the dark ring gaps appear bright when viewed towards the Sun, which shows the gaps are not empty of material. The spacecraft measured the temperature of the moon Titan. In November 1980, Voyager 1 visited Saturn and took higher resolution photographs of the planet, rings, and moons. These photos were able to show the surface features of the moons. Voyager 1 went close to Titan and gained much information about its atmosphere. In August 1981, Voyager 2 continued to study the planet. Photos taken by the space probe showed that changes were happening to the rings and atmosphere. The Voyager spacecraft discovered a number of moons orbiting close to Saturn's rings, as well as discovering new ring gaps. On July 1, 2004, the Cassini−Huygens probe entered into orbit around Saturn. Before then, it flew close to Phoebe, taking very high-resolution photos of its surface and collecting data. On December 25, 2004, the Huygens probe separated from the Cassini probe before moving down towards Titan's surface and landed there on January 14, 2005. It landed on a dry surface, but it found that large bodies of liquid exist on the moon. The Cassini probe continued to collect data from Titan and a number of the icy moons. It found evidence that the moon Enceladus had water erupting from its geysers. Cassini also proved, in July 2006, that Titan had hydrocarbon lakes, located near its north pole. In March 2007, it discovered a large hydrocarbon lake the size of the Caspian Sea near its north pole. Cassini observed lightning occurring in Saturn since early 2005. The power of the lightning was measured to be 1,000 times more powerful than lightning on Earth. Astronomers believe that the lightning observed in Saturn is the strongest ever seen. Notes Refers to the level of one bar atmospheric pressure Orbital information is based on the barycentre of the Saturn system, the centre of mass, not the geometric centre. Barycentre measurements are used because they are not changed by the daily movement of the moons. Related pages List of planets References Notes Further reading Theoretical description of the rings of Saturn. A WAV file of radio emissions from Saturn.

Slavery is when a person is treated as the property of another person. This person is usually called a slave, with the owner being called a slavemaster. It often means that slaves are forced to work, or else they will be punished by the law (if slavery is legal in that place) or by their master. There is evidence that even before there was writing, there was slavery. There have been different types of slavery, and they have been in almost all cultures and continents. Some societies had laws about slavery, or they had an economy that was built on it. Ancient Greece and Ancient Rome had many slaves. During the 20th century almost all countries made laws forbidding slavery. The Universal Declaration of Human Rights says that slavery is wrong. Slavery is now banned by international law. Nevertheless, there are still different forms of slavery in some countries. The English word "slave" comes from the medieval word for the Slavic peoples of Central Europe and Eastern Europe, because these were the last ethnic group to be captured and enslaved in Central Europe. According to Adam Smith and Auguste Comte, a slave was mainly defined as a captive or prisoner of war. Slave-holders used to buy slaves at slave auctions. In many cases slaves are not allowed rights. Early civilizations Slavery has existed for a long time. Early hunter-gatherers had no use for slaves. They did everything for themselves. Having another pair of hands to help them meant another mouth to feed. Slavery or owning another person made no sense to these people. Once men gathered in cities and towns and there was more than enough food, having a cheap supply of labor made sense. This is when the earliest forms of slavery appeared. Slavery can be traced back to the earliest records, such as the Code of Hammurabi (c. 1760 BC). This refers to it as an established institution. In the Ancient Near East, captives obtained through warfare often became slaves. This was seen by the laws in the Bible book of Deuteronomy as a legal form of slavery. But the Israelites were not allowed to enslave other Israelites. The Deuteronomic Code calls for the death penalty for the crime of kidnapping Israelites to enslave them. In Ancient Egypt, slaves were mainly prisoners of war. Other ways people could become slaves was by inheriting the status from their parents who were slaves. Someone could become a slave if he could not pay his debts. People also sold themselves into slavery because they were poor peasants and needed food and shelter. The lives of slaves were normally better than that of peasants. Young slaves could not be put to hard work, and had to be brought up by the mistress of the household. Not all slaves went to houses. Some also sold themselves to temples, or were assigned to temples by the king. Slave trading was not very popular until later in Ancient Egypt. Afterwards, slave trades sprang up all over Egypt. In many places, citizens were partly or fully protected from being enslaved, so most slaves were foreigners. Slavery in ancient Rome Slaves were important in society and the economy of ancient Rome. They did simple manual labor and domestic services, but also could have complex jobs and professions. Teachers, accountants, and physicians were often slaves. Greek slaves were often highly educated. Most slaves, like those sentenced to slavery as punishment, worked on farms, in mines, and at mills. Their living conditions were brutal, and their lives short. Slaves were considered property under Roman law and had no legal personhood. Unlike Roman citizens, they could suffer corporal punishment, sexual exploitation (sex workers were often slaves), torture, and summary execution legally. Slave's words could not be accepted in a court of law unless the slave was tortured—a practice based on the belief that slaves would be too loyal to their masters reveal damaging evidence unless coerced. Over time, however, slaves gained some legal protection, including the right to file complaints against their masters. Attitudes changed in part because of the influence among the educated elite of the Stoics, whose egalitarian views of humanity extended to slaves, and because of slave rebellions. Roman slaves could hold property which, even though it belonged to their masters, they were allowed to use as if it were their own. Upper class slaves were allowed to earn their own money. With enough money they could buy their freedom. After the Roman Empire broke up, slavery gradually changed into serfdom. The Arab slave trade Historians estimate that between 650 AD and the 1960s, 10 to 18 million people were enslaved by Arab slave traders. They were taken from Europe, Asia and Africa across the Red Sea, Indian Ocean, and Sahara desert. Male slaves were often employed as servants, soldiers, or workers by their owners. Many male slaves were castrated. It is estimated that as many as 6 out of every 10 boys bled to death during the process. But the high price of Eunuchs made it worthwhile. According to Ronald Segal, author of Islam’s Black Slaves: The Other Black Diaspora (2002), "The calipha in Baghdad at the beginning of the 10th Century had 7,000 black eunuchs and 4,000 white eunuchs in his palace”. Women and children taken as slaves were mainly used as servants and concubines. While the later Atlantic slave trade concentrated on men for labor, the Arab slave trade started with men and boys, but shifted over time to concentrate more on woman and young girls for sexual purposes. By the 1900s, Arab slave traders had taken between 10 and 20 million slaves out of Africa. The Atlantic slave trade For four centuries, beginning in the late 15th century, millions of Africans were taken as slaves by Europeans. Europeans began exporting Africans to the New World as a source of cheap labor on colonial plantations. Between 1452 and 1455, Pope Nicolas V issued a series of papal bulls authorizing the Portuguese to take African slaves. At first slave traders raided coastal areas and carried black people off. But the mines and fields of the colonies needed more and more slaves. In the early 16th century Spain began to issue licenses and contracts to supply slaves. By the 1750s large slaving companies were established. Most of Europe at the time was involved in the slave trade. Slavery in the United States Many Europeans who arrived in North America during the 17th and 18th centuries came under contract as indentured servants. The change from indentured servitude to slavery was a gradual process in Virginia. The earliest legal documentation of such a shift was in 1640. This is where an African, John Punch, was sentenced to lifetime slavery for attempting to run away. This case also marked the disparate treatment of Africans as held by the Virginia County Court, where two white runaways received far lesser sentences. After 1640, planters started to ignore the expiration of indentured contracts. They kept their servants as slaves for life. This was demonstrated by the case Johnson v. Parker. The court ruled that John Casor, an indentured servant, be returned to Johnson who claimed that Casor belonged to him for his life. According to the 1860 U. S. census, 393,975 individuals, representing 8% of all US families, owned 3,950,528 slaves. One-third of Southern families owned slaves. Slavery in United States was legally abolished by Thirteenth Amendment to the United States Constitution in 1865. Slavery today Millions of people are still slaves in some parts of the world, mostly in South Asia and Africa. It is less common in the developed world because of better law enforcement, but it still happens there as well. The ways in which it is done have changed. Today, slaves may work because of things like a high debt (for example, slaves have to work to pay off a debt). Many victims are told that their families will be harmed if they report the slave owners. Many slaves are forced to be domestic servants. In some cases, their families sell them to the slave owners. Some slaves have been trafficked from one part of the world to another. These people are illegally in their host country, and therefore do not report the abuse. Forced prostitution is a type of slavery. Another form of slavery still happening today is forced child labor. Some children have to work in mines or in plantations, or they have to fight wars as child soldiers, for no pay. One study says that there are 27 million people (but others say there could be as many as 200 million) in slavery today. Other terms that describe the recruitement of laborers, and that may have similarities to slavery are Blackbirding, Impressment and Shanghaiing. Countries Some of the countries where there is still slavery are in Africa, the Middle East, and South Asia. In summer 2007, 570 people were found to be slaves for brick makers in China. They included 69 children. The Chinese government made a force of 35,000 police check northern Chinese brick kilns for slaves, and sent lots of kiln supervisors and officials to prison and sentenced one kiln foreman to death for killing a worker who was a slave. In Mauritania, it is thought that up to 600,000 men, women and children, or 20% of the population, are slaves, and that many of them are used as bonded labour. Slavery in Mauritania was made illegal in August 2007. In Niger, there is also much slavery. A Nigerian study has found that more than 800,000 people are slaves, almost 8% of the population. Child slavery has commonly been used when making cash crops and mining. According to the United States Department of State, more than 109,000 children were working on cocoa farms alone in Côte d'Ivoire (Ivory Coast) in 'the worst forms of child labour' in 2002. In November 2006, the International Labour Organization said that it would prosecute members of the junta that rules Myanmar (also called Burma) at the International Court of Justice for "Crimes against Humanity". This is because the military makes some citizens do forced labour. The International Labour Organisation says that it thinks that about 800,000 people are forced to work this way. Scholars of Islamic law have condemned the revival of the slave trade of non-Muslim women by the Islamic State of Iraq and the Levant. Stopping slavery An agitation called Abolitionism against slavery began in Christian countries in the 18th century. First they abolished the slave trade so more people wouldn't become slaves. In 1833, the British Empire stopped slavery. Several other countries followed. In the United States, disagreement over slavery led to the American Civil War and the Emancipation Proclamation. In 1865, when the North won, all slaves were made free. Still more countries abolished slavery afterwards. Pedro II of Brazil abolished it in 1888. Forced labor however continued, either against the law or by debt peonage or other methods which the laws of the various countries did not count as slavery. Famous people who were slaves Aesop circa 6th century BC Spartacus (died 71 BC) Epictetus (about AD 55 - AD 125) Pope Callixtus I (died AD 222) Saint Patrick (about AD 387-461) Olaudah Equiano (about 1745-1790) George John Scipio Africanus (1763-1834) Denmark Vesey (about 1767-1822) Sojourner Truth (about 1797-1883) Dred Scott (about 1799-1845) Nat Turner (1800-1831) Harriet Jacobs (about 1813-1897) Frederick Douglass (about 1818-1895) Harriet Tubman (1820-1913) (1830-1882) Booker T. Washington (1856-1915) Solomon Northup Related pages Crimes against humanity Debt bondage Unfree labour Serfdom Human trafficking Slave trade Sexual slavery American Civil War Haiti References

Many philosophies and religions say that a soul is the part of a living human being which is supernatural and lives after death. It is usually said to be immortal. It cannot be discovered by science, because it cannot be tested in any controlled way. Many different opinions exist as to what happens to personal experience after death. Reincarnation is a belief that after the body dies, the soul will be born again in another body. It is important to Hinduism. Buddhists understand the idea of an eternal soul, and the idea of simple annihilation as delusion; they say that there is no unchanging, permanent self, soul or essence in phenomena. Buddhists believe in transmigration, or rebirth in samsara or other planes of existence, based on how they understand kamma (Pāli; karma in Sanskrit), and nibbana (nirvana in Sanskrit) for Enlightened ones. Resurrection is the Christian belief that a soul returns in the same body. In most Christian denomination this was realized in Jesus Christ but is also the promise for all souls; see heaven, hell, and Final Judgement. Most atheists say that there is no such thing as a soul, and that the body is the only part of a person. Popular culture In popular culture, soul usually means deep feeling and commitment. It is in this sense that the word appears in the term soul music. However that music was also influenced by gospel music which was religious. One popular idea about souls that is easy to express, is that a person is a soul, and has a body. The soul is the "I" in "I exist" that feels and lives life. What people call the mind could be part of the soul: one soul started this article, other souls have edited it, and another soul is reading it. This view, however, implies that the human body is a possession, and seems to devalue bodies that do not have souls as defined or understood by the speaker (some people say that animals, heretics, and people of another religion do not have souls). Like most uses of the verb to be, there is an ideology in these simple words. Christianity teaches that all humans have an immortal soul. This means that it is a part of them which does not die when their physical body dies, but lives on with them to heaven or to hell. Christians believe that the soul is the 'breath of life' which God gave to Adam. In Japan the soul is believed to weigh 21 grams. This belief may have been influenced by the observations of Dr. McDougall in the early 1900s. Characteristics One distinction often made is between soul, which is distinct from other souls, and spirit which may be combined with that of other beings. The idea of the Holy Spirit in Christianity, for example, is a universal and shared spirit many souls are part of, and which is expressed on Earth in that faith by "the Church" meaning "the body of Christ" meaning "all bodies that follow Jesus." This could be more inclusive than the is/has view of souls and bodies. Related pages Ancient Egyptian concept of the soul References Death customs Theology

Soap is a chemical compound resulting from the reaction of an alkali (commonly sodium or potassium hydroxide) with a fatty acid. Soaps are the metallic salts of long chain fatty acids. When mixed with water during bathing or washing, they help people and clothes get clean by lowering the chance of dirt and oil to get to the skin or fabric. Soaps are made from animal fats or vegetable oils. There are two basic steps in making soap. They are called Saponification and Salting-out of soap. Some people like to make their own soap. Soap cleans very well in soft water. It is not toxic to water life. It can be broken down by bacteria. However, it is slightly soluble in water, so it is not often used in washing machines. It does not work well in hard water. It cannot be used in strongly acidic solutions. Mild hand soaps are only basic enough to remove unwanted skin oils. For other forms of oil, dishwashing soap is strong enough to remove almost all forms of oil without damaging petroleum products such as plastics. It does not damage skin either. Soap has been made in many ways. Humanity has used soap-like things for thousands of years. The earliest recorded evidence of the making of soap-like materials dates back to around 2800 BC in Ancient Babylon and Sumeria. They were soap solutions, or soapy water. People made them by mixing ashes with water and fat and boiling them. The Babylonians used water, alkali and cassia to make soap. A recipe for solid soap appeared in about 800 c.e. Gauls added salt to the soap solution to make the solid soap fall out. The Ebers papyrus (Egypt, 1550 BC) suggests that ancient Egyptians bathed often and had animal and vegetable oils with alkaline salts to make a soap-like substance. Egyptian documents say that a soap-like substance was used in the preparation of wool for weaving. Related pages Soap made from human corpses References Care Chemistry

A summary is a condensed explanation of an event, story, document, etc.. i.e. "summing up the facts." They are not constrained to any medium or topics. Not to be confused with abstract, which is a summary of a document. There are many different levels of summarization that can be done. The summarizer may choose any length, but the sumarees may not appreciate anything more than absolutely necessary to get the required facts. Summaries help to spread information fast. They also help people make decisions on if it is something worth looking further into. EXAMPLES A quick "good/bad" can suffice in some situations. In other situations, the summary may rival the length of the original. "This book was really cool. This guy drives a pickup to work everyday, and has a dangerous job." Many scientific journals publish a summary for every large article so people who do not have much time can read the main information quickly without spending too much time reading the article. References Writing

A service is a job or work done for someone else. All the service trades in a place form a service economy. The service economy can be in a region like a country or in a town or city. Structure Often, the person who gives the service will get something in return for the service. The person who gives the service can get money in return. The person who gives the service can get goods in return. The person who gives the service can get another service in return. This is a type of trade. Economics

There are several meanings of the word sense. This page is for disambiguation - there are more detailed articles on each meaning: When a word has several meanings, one can refer to it as being used "in the sense of..." some context or other. In Simple English for instance we avoid using words in unusual senses. The sensory system of animals The human sensory system is usually said to have six senses: Hearing is the sense of sound that comes into our ears. Sight is the sense of seeing things with our eyes. Touch is the sense of feeling things with our skin. Taste is the sense of the flavor of things with our tongues Smell is the sense of smelling things with our noses. Kinesthetic sense is knowing where your whole body is and where it is not. Other animals may have other senses. Fish have lateral lines which detect changes in the water pressure around them, and some can detect changes in electric fields around them. Sense in language Sense in this context is the meaning conveyed by language. Another use is to flag whether an argument or statement is correct and understood. "That makes no sense" or "That is nonsense" are examples from everyday speech. A variation of this is to say that something does not make "economic sense". Usually these words signal a political dispute or some failure to define terms correctly. The term "common sense" is thinking based on a wide experience of life. It used to mean practical wisdom. It has a long history of being used in politics, often to mean that some idea will be accepted or rejected because of human nature (what people are like). Basic English 850 words

A synagogue is a place where Jews meet to worship and pray to God. In Hebrew, a synagogue is called beit knesset, which means, a "house of gathering". The word "synagogue" comes from sunagoge, which is a Greek word. In a synagogue, Jews carry out the Jewish services, which consist of prayers, sometimes with special actions. A synagogue will usually have a large room for prayers. There might be some smaller rooms for studying. There will be some offices. There will also usually be a big room for special events. The front of a synagogue faces towards Jerusalem in Israel. In the front is the holiest part of the synagogue, the Ark. This is a closet which has the Torah scrolls inside. The Torah scrolls have the holy writings of Judaism on them. The Ark usually has a curtain in front of it. On top of the Ark is light which is always lit, called the “Eternal Lamp”. It is a symbol which means that God is always there. Every synagogue has a raised platform called the “Bimah”. The person who reads the Torah scroll stands there when he reads. The Bimah is either in the middle of the hall, or in front of the Ark. In some synagogues men and women sit in different places. Some synagogues even have a short wall so that they can not see each other. This is so that the people will think about the prayers better. Jews may call synagogues by different names. Many Orthodox and Conservative Jews living in English-speaking countries use the name "synagogue" or the word "shul", which is Yiddish. Jews who speak Spanish or Portuguese call synagogues esnoga. Some Jews call the synagogue a temple. Jewish worship does not have to be carried out in a synagogue. It can be wherever a minyan of ten Jews are. It could be in someone's home or anywhere such as a cruise liner or an airplane. Some synagogues have a separate room or torah study, this is called the "beth midrash" meaning house of study. Some kinds of Jewish worship can be done alone or with fewer than ten people. Synagogues are places were Jews can worship. Judaism

Scarcity in economics is the lack of various forms of capital. Scarcity can be used to describe an economic situation in economics, or it can be used to describe more general situations. In economics, scarcity is the result of people having "Unlimited Wants and Needs," or always wanting something new, and having "Limited Resources." Limited Resources means that there are never enough resources, or materials, to satisfy, or fulfill, the wants and needs that every person have. Scarcity is called the "basic economic problem," meaning that it always exists. Scarcity exists due to the effects of nature such as drought, floods, storms, pest infestation, fire and other things. Real scarcity can also exist by over use of non-renewable resources. Goods (things) and services are also scarce because there are only a limited number of things in the world and due to the limits of technology and our own priorities. More scarce goods and services have higher prices, because of supply and demand. Gold is used less than iron, but the price of gold is much higher, because gold is more scarce. Lawyers are paid more than janitors, because there is scarcity of qualified lawyers. Scarcity of capital is the main constraint in economic development of developing countries. Economic growth is an increase in the production and consumption of goods and services. It entails increasing population or per capita consumption. It is represented by increasing Gross Domestic Product (GDP). Scarcity refers to limited resources. These resources are the inputs of production i.e., land, labor and capital. Artificial scarcity Artificial scarcity is when somebody limits the amount of goods or services that are available, although it would be simple to make more. Artificial scarcity can increase profits for a business. Some people will pay more for something that is scarce, because it shows that they are rich (a status symbol). Copyrights, patents, monopolies, cartels, planned obsolesence can make artificial scarcity. References Microeconomics