title: Writing

paragraphs: Writing is the act of recording language on a visual medium using a set of symbols. The symbols must be known to others, so that the text may be read.

paragraphs: A text may also use other visual systems, such as illustrations and decorations. These are not called writing, but may help the message work. Usually, all educated people in a country use the same writing system to record the same language. To be able to read and write is to be literate.

paragraphs: Writing differs from speech because "the readers need not be present at the time". We can read writing from long ago, and from different parts of the world. Text stores and communicates knowledge. Writing is one of the greatest inventions of the human species. It was invented after people settled in towns, and after agriculture started. Writing dates from about 3,300, which is over 5000 years ago, in the Middle East.

paragraphs: Writing today is usually on paper, though there are ways to print on almost any surface. Television and movie screens can also display writing, and so can computer screens. Many writing materials were invented, long before paper. Clay, papyrus, wood, slate and parchment (prepared animal skins) have all been used. The Romans wrote on waxed tablets with a pointed stylus; this was popular for temporary notes and messages. The later invention of paper by the Chinese was a big step forward.

paragraphs: Writing is traditionally done using a hand tool such as a pencil, a pen, or a brush. More and more, however, text is created by input on a computer keyboard.

paragraphs: Therefore, depending on an author's definition of writing, the term may be used in different ways. With many early systems we do not know what they do convey. The central idea is that "a full writing system must be able to represent anything that might be said in spoken language". From this point of view the invention of the rebus is an essential step.

paragraphs: We can only be sure a sign system is full writing if we can translate the symbols into a modern language. In the case of some ancient scripts we cannot do this.

paragraphs: Writing was invented independently a number of times. The Sumerian, the ancient Egyptian, the Chinese and the Mayan writings are separate in their invention. All these writing systems started with "pictographs", symbols that stood for things. Then they developed a mixture of methods. Our own alphabetic system is different. It is based on the sounds of spoken language. All alphabets are modified versions of the first one, which originated with the Phoenicians and the Ancient Greeks.

paragraphs: The Sumerians lived in Mesopotamia, between the Tigris and Euphrates rivers. 5000 years ago this was a fertile region and is now mostly in Iraq. The Sumerians developed a form of writing called cuneiform. Triangular marks were pressed into soft clay tablets. After the clay had dried in the sun the tablets were baked. Then they were carried somewhere else for others to read. We know that its first uses were for trade, accounting and administration.

paragraphs: The earliest signs were mostly pictorial, but soon they stood as symbols for objects, ideas and sounds. This writing system was extremely successful, and outlasted the Sumerian empire. It was then used by other civilisations in the Middle East, such as the Old

paragraphs: Akkadian, Babylonian, Assyrian, Elamite, Hittite, Old Persian and Ugaritic empires. The last cuneiform inscription was dated as 75. Thus the system had lasted for more than 3000 years. Each version of cuneiform had to be deciphered separately, because all the languages were different. Documents (including stone objects) written in more than one language provided the clues.

paragraphs: This is the most famous of the old forms of writing, or "scripts". It was invented at roughly the same time as cuneiform, yet was quite different in style, and used different materials. Egyptians ended up with three writing systems for the same language. They were:

paragraphs: The writing tools used varied according to the material which was written on. The two cursive scripts were written with reed pens and carbon inks onto papyrus. If the material was cloth, then the writing was done by a brush. Many examples survive. The hieroglyphs were inscribed (carved) into stone (hammer & chisel) or painted onto stone surfaces. Many survive, some with the original colours intact. The key event in the decipherment of hieroglyphic writing was the discovery of the Rosetta Stone. This is a granite slab with the same message written in hieroglyphic, demotic and in Greek. Ancient Greek is well understood, and made possible the interpretation of the other two scripts.

paragraphs: Chinese is the language with the largest number of native speakers. Its history dates back to about 1400. The Chinese writing system is idio-syllabic, a mixed method using characters which may have one or more of these elements:

paragraphs: Chinese has a huge number of characters: in the region of 50,000. Because of this, printing methods were never really successful in China, despite their early invention. In the 14th century Wang Tzhen had sixty thousand wood block characters cut, a huge investment in time and money. He printed 100 copies of a local gazette, and was author of a treatise on agriculture and other technical works. Even with printing machines from Europe in the 19th century, the process was hampered by the huge number of characters, which slowed the "composition" to a snail's pace.

paragraphs: China has eight regional languages that are mutually unintelligible, and many true dialects. The system appears to work mainly because as many as 70% speak Mandarin. Fluency in Chinese reading and writing is undoubtedly difficult to achieve, and this must act as a brake on the drive for literacy. There have been a number of attempts to reform or simplify the system. The most radical in Pinyin, which is a program to replace Chinese characters with an alphabetic system. This was supported by Mao, but faltered after his death.

paragraphs: It seems that the idea of an alphabet–a script based entirely upon sound–arose only once, and has been copied and adapted to suit many different languages. Although no alphabet fits its language perfectly, it is flexible enough to fit any language approximately. It was a unique invention.

paragraphs: Our alphabet is called the Roman alphabet, as compared with the Cyrillic and other alphabets. All of these come from the ancient Greek alphabet, which dates back to about 1100 to 800. The Greek alphabet was probably developed from the Phoenician script, which appeared somewhat earlier, and had some similar letter-shapes.

paragraphs: The Phoenician language was a Semitic language, often called Canaanite. The Semitic group of languages includes Arabic, Maltese, Hebrew and also Aramaic, the language spoken by Jesus. We do not know much about how the alphabetic idea arose, but the Phoenicians, a trading people, came up with letters which were adapted by the early Greeks to produce their alphabet. The one big difference is that the Phoenician script had no pure vowels. Arabic script has vowels which may be shown by diacritics (small marks above or below the line). The oldest Qu'ran manuscripts had no diacritics. Israeli children today use texts with vowel 'dots' added, to about the third grade.

paragraphs: No ancient script, alphabetic or not, had pure vowels before the Greeks. The Greek alphabet even has two vowels for 'e' and two for 'o', to distinguish between the long and short sounds. It is fairly clear from this that careful thought went into both the Phoenician invention and the Greek adaptation. However, no details survive of either process.

paragraphs: Semitic scripts apparently derive from "Proto-Sinaitic", a script of which only 31 inscriptions (plus 17 doubtful) are known. It is thought by some researchers that the original source of this script was the Egyptian hieratic script. By the late Middle Kingdom (about 1900) hieratic had added some alphabetic signs for representing the consonants of foreign names. Egyptian activity in Sinai was at its height at that time. A similar idea had been suggested many years before.

paragraphs: There are a number of scripts which have never been deciphered, despite much effort. Perhaps the most famous are the script of the Indus Valley civilization, and Etruscan. The Indus River civilisation predates other literate civilisations on the Indian subcontinent, going back to about 2500. Their cities of Mohenjo-Daru and Harappa were well-planned, with good drainage. The script is found on seal stones, terracotta, bronze, bone and ivory. All are brief, and the language is unknown.

paragraphs: The Etruscan language used Greek letter-forms, and is found mainly on Etruscan tombs, from Tuscany through to Venice. They were an empire before the Romans, who defeated them, and absorbed their ideas. All knowledge of their language was lost, except that some of the names on tomb memorials can be read from the Greek letters.

paragraphs: The Tărtăria tablets are three tablets discovered in 1961 in the village of Tărtăria (Hungarian: Alsótatárlaka). This is about from Alba Iulia in Romania. The tablets, dated to around 5300 BC, have symbols in clay: the "Vinča symbols". Some claim they are a yet undeciphered language. If this is so, they would be the earliest known form of writing. In 1908 similar symbols were found during excavations, by Miloje Vasić (1869–1956) in Vinča. This is a suburb of Belgrade (Serbia), some 300 km from Turdaș. Later, more were found in another part of Belgrade. Since 1875 over one hundred and fifty Vinča sites have been found in Serbia alone. Many, including Vinča itself, have not been fully excavated. The culture of the whole area is called the Vinča culture. Although some of these symbols look exactly the same as some letters in Etruscan, Greek, and Aramaic, they are generally regarded as an original, independent development.

paragraphs: It is only in the last 150 years that most people have been able to read and write in Europe and North America. In many other parts of the world this did not happen until the 20th century. Until then, literacy was mainly for clerics, that is, people who had training as priests. Even wealthy people were often illiterate, and used scribes to write for them. The invention of printing came before mass literacy. Before 1500, each book had to be created by hand, so there were few books available compared to the billions in the world today. Mass literacy needed cheap books.

paragraphs: Even now, there is still widespread illiteracy.

paragraphs: The ordinary use of writing by means of a pen and paper. Can refer to writing for oneself, as in a diary, but mostly it refers to sending letters. Once it was almost the only means of communication between people who were separated. Now, the telephone and e-mail are the most common means of distance communication.


Rock


title: Plato

paragraphs: Plato was one of the greatest classical Greek philosophers. He lived from 427 BC to 348 BC. Plato created the first university school, called "The Academy". Plato was a student of Socrates (who did not write) and the teacher of Aristotle, who founded another university, known as the Lyceum. Plato wrote about many ideas in philosophy that are still talked about today. He wrote about ideas of deductive reasoning. One modern philosopher, Alfred North Whitehead, said that all philosophy since Plato has just been comments on his works.

paragraphs: Plato wrote his books in the form of dialogues with two people or more talking about ideas, and sometimes disagreeing about them.

paragraphs: Socrates is usually the main person in Plato's dialogues. Usually, Socrates talks with people about their ideas, and tries to see if they believe anything that is illogical. Other people in the stories often become angry with Socrates because of this. People who study Plato argue about whether Socrates really said the same things that Plato makes him say, or whether Plato just used Socrates as a character, to make the ideas he was talking about seem more important.

paragraphs: Plato opposed the rhetorics of sophism and insisted on true justice and equality in his work "Gorgias", and on immortality of soul in "Phaedo".

paragraphs: One of Plato's most famous works is "The Republic" (in Greek, "Politeia," or 'city'). In that work, he describes Socrates's vision of an "ideal" state. The method of questioning in this dialogue, called the Socratic method, is as important as the content. "The Republic" contains ideas of Socrates: "Socrates said it, Plato wrote it."

paragraphs: The "Laws" is Plato's longest dialogue and probably his last.

paragraphs: There are many dialogues that were supposed to be written by Plato. This list includes those he probably did write.


title: Book

paragraphs: A book is a set of printed sheets of paper held together between two covers. The sheets of paper are usually covered with a text, language and illustrations. The book is a more flexible format than the earlier idea of the scroll. The change from scrolls to books began in the Roman Empire, and took many centuries to become complete.

paragraphs: A writer of a book is called an author. Someone who draws pictures in a book is called an illustrator. Books can have more than one author or illustrator.

paragraphs: A book can also be a text in a larger collection of texts. That way a "book" is perhaps written by one author, or it only treats one subject area. Books in this sense can often be understood without knowing the whole collection. Examples are the Bible, the Illiad or the Odyssey – all of them consist of a number of "books" in this sense of the word. Encyclopedias often have separate articles written by different people, and published as separate volumes. Each volume is a book.

paragraphs: "Hardcover" books have hard covers made of cardboard covered in cloth or leather and are usually sewn together. "Paperback" books have covers of stiff paper and are usually glued together. The words in books can be read aloud and recorded on tapes or compact discs. These are called "audiobooks".

paragraphs: Books can be borrowed from a library or bought from a bookstore. People can make their own books and fill them with family photos, drawings, or their own writing. Some books are empty inside, like a diary, address book, or photo album. Most of the time, the word "book" means that the pages inside have words printed or written on them.

paragraphs: Some books are written just for children, or for entertainment, while other books are for studying something in school such as math or history. Many books have photographs or drawings.

paragraphs: There are two main kinds of book text: fiction and non-fiction.

paragraphs: These books are novels, about stories that did not happen, and have been imagined by the author. Some books are based on real events from history, but the author has created imaginary characters or dialogue for the events.

paragraphs: Books of non-fiction are about true facts or things that have really happened. Some examples are dictionaries, cookbooks, textbooks for learning in school, or a biography (someone's life story).

paragraphs: Between the written manuscript and the book lie several inventions. Manuscripts are hand-made, but books are now industrial products.

paragraphs: A common type of manuscript was the scroll, which was a long sheet rolled up. The sheet could have been made of papyrus (made by the Egyptians, by weaving the inner stems of the papyrus plant and then hammering them together), or parchment or vellum (very thin animal skin, first used by the ancient Greeks), or paper (made from plant fibers, invented by the Chinese). Manuscripts of this kind lasted to the 16th century and beyond. Turning the manuscript into a book required several developments.

paragraphs: The Romans were the first people to put separate pieces of manuscript between covers, to form a "codex". This was more convenient to handle and store than scrolls, but was not yet a book as we understand it.

paragraphs: Scrolls and codices were written and copied by hand. The Chinese invented "woodblock printing", where shapes are carved out of a block of wood, then ink is applied to the carved side, and the block is pressed onto paper. This woodcut method was slow because the symbols and pictures were made by cutting away the surrounding wood.

paragraphs: Johannes Gutenberg was the first to invent a machine for printing, the printing press, in the 15th century. This involved more than just a press, it involved the production of movable metal type suitable for the machine process.

paragraphs: Initially, the machines were slow, and needed a printer's muscle to make them work. The Industrial Revolution brought steam power and later electrification.

paragraphs: Paper had been invented in China in the 8th century, but it was kept secret for a long time. In Europe hand-made paper was available from about 1450. It was cheaper than parchment but still expensive, and the early printing was a slow process. Therefore, books remained rare. In 1800 the first machines for making paper from wood pulp were invented. New kinds of inks were also invented for various purposes, and machines were driven by steam engines and later by electricity.

paragraphs: The common cheap supply of paper fed the faster printing machines, and books became cheaper. At the same time, in America, Britain and continental Europe, more people learnt to read. So, in the 19th century, many ordinary people could afford to buy books and could actually read them. Also in the 19th century came public libraries, so poorer people could get access to the best books.

paragraphs: Printing was done on large sheets of paper, which were then folded, guillotined (cut) and sewn into the covers. Bookbinding and all the other processes have been done by machines since the 19th century.

paragraphs: Today some of the technologies have been changed, especially those involving illustration and typography. However, books look much the same as they did, with more illustration in colour, but basically the same. That is because experience has shown that readers need certain things for pleasurable reading. Graphic design and typography are the practical arts used to make books attractive and useful to readers.


title: Sundial

paragraphs: A sundial shows the current solar time during the day. It does this because the sun appears to move through the sky. At different times in the day when the sun is shining, a shadow is cast in different places on the dial. A person marks the dial with the time at a certain shadow. This lets users easily see the time. There are a few commonly seen designs, such as the 'ordinary' or standard garden sundial. However, sundials can be designed for any surface where a fixed object casts a predictable shadow.

paragraphs: Ancient Egypt had sundials. Other cultures developed them further, including the Greeks and Romans.


title: Peninsula

paragraphs: A peninsula is a region of land that sticks out in a body of water. It is also defined as a piece of land with water on three sides.

paragraphs: Many countries are on peninsulas, and may either take up part of a peninsula (such as Portugal) or all of it (such as India). Parts of a country may also be on a peninsula. For example, Jutland is a peninsula, as is Baja California in Mexico.

paragraphs: If Eurasia is considered a continent then the continent of Europe is technically a peninsula. In this case, the great peninsulas of Europe, the Iberian, Italian, and Balkan peninsulas would technically be peninsulas within peninsulas. The area of the European Peninsula, comprised of Europe minus Russia, Fennoscandia, and any islands, is roughly 4.4 million square kilometers.

paragraphs: The Arabian Peninsula is usually cited as the largest peninsula in the world with an area of 3,237,500 square kilometers.


title: Derivative

paragraphs: A derivative is something created from a Primary source, and can mean different things.


title: Combinatorial game theory

paragraphs: Combinatorial game theory, also known as CGT is a branch of applied mathematics and theoretical computer science that studies combinatorial games, and is distinct from "traditional" or "economic" game theory. CGT arose in relation to the theory of impartial games, the two-player game of Nim in particular, with an emphasis on "solving" certain types of combinatorial games.

paragraphs: A game must meet several conditions to be a combinatorial game. These are:

paragraphs: Combinatorial Game Theory is largely confined to the study of a subset of combinatorial games which are two player, finite, and have a winner and loser (i.e. do not end in draws.)

paragraphs: These combinatorial games can be represented by trees, each vertex of which is the game resulting from a particular move from the game directly below it on the tree. These games can be assigned game values. Finding these game values is of great interests to CG theorists, as is the theoretical concept of game addition. The sum of two games is the game in which each player on her/his turn must move in only one of the two games, leaving the other as it was.

paragraphs: Elwyn Berlekamp, John Conway and Richard Guy are the founders of the theory. They worked together in the 1960s. Their published work was called "Winning Ways for Your Mathematical Plays".

paragraphs: In the theory, there are two players called "left" and "right". A game is something that allows left and right to make moves to "other games". For example, in the game of chess, there is a usual starting setup. One could also, however, think of a chess game after the first move as a different game, with a different setup. So each position is also called a game.

paragraphs: Games have the notation {L|R}. formula_1 are the games the left player can move to. formula_2 are the games the right player can move to. If you know chess notation, then the usual chess setup is the game

paragraphs: The dots "..." mean there are many moves, so not all are shown.

paragraphs: Chess is very complex. It is better to think of easier games. Nim, for example, is much simpler to think about. Nim is played like this:

paragraphs: The easiest game of Nim starts with no counters at all! In such a case, neither player can move. That is shown as , or 0). If instead right moves first, there will be no more moves for left. So both left and right can make a move to 0. That is shown as <nowiki>, or {0|0}</nowiki>. The first player to move will win. Games equal to {0|0} are very important. They are written with the symbol, * (star).


title: Nim

paragraphs: Nim is a simple game used for examples in combinatorial game theory. The rules of nim are simple:

paragraphs: There is a simple mathematical strategy to play the game perfectly. If both players play perfectly, the winner is determined by the initial setup.


title: Blue

paragraphs: Blue is one of the colors of the rainbow that people can see. It is one of the seven colors of the rainbow along with red, orange, yellow, green, indigo and violet. Apart from indigo and violet, it has the shortest wavelength of these colors (about 470 nanometers).

paragraphs: Blue is the color of the Earth's sky and sea. Earth looks blue when seen from outer space by astronauts.

paragraphs: Blue is a color used to show coldness. It is also one of the colors your lips can turn if you are chilly.

paragraphs: Blue is the color of a "bluebird". A blue jay is the color blue.

paragraphs: The color blue is sometimes associated with sadness, which may be where the name of the music style The Blues comes from.

paragraphs: In Western cultures since the 1940s, blue is associated with men/boys, while pink is associated with women/girls. Before the 1940s, it was the other way around, so blue was for women/girls and pink was for men/boys. Nobody knows exactly why it changed.


title: Memory

paragraphs: Memory is the personal record of past experiences. It is the brain's ability to store information to use later. The Greeks considered memory (Mnemosyne) as the mother of Muses, for without her there would be no art and no science.

paragraphs: Memory is studied in sciences known as "cognitive psychology".

paragraphs: There are two types of memory: short-term and long-term memory, or known as working memory and reference memory.


title: Murder

paragraphs: Murder is when one person kills another person on purpose. If a person does something that makes someone else die, without the intent of killing, it is homicide and may be manslaughter. An accident caused by carelessness may be negligent homicide. Sometimes, a death caused by someone else may not be a crime, for example killing in self-defense.

paragraphs: A person who commits murder is called a murderer. The legal definition of "murder" and "manslaughter" may be different in different countries, and is very much argued on: for example, killing in war is not usually called "murder" by those who fight in the war. Killing in self defense (if people being attacked with death seeming imminent kill the attacker, or someone kills an intruder who has burglarized their dwelling) is usually not "murder", but sometimes manslaughter. Many countries do not even have manslaughter as a legal concept, and only have murder; the countries that do not have manslaughter charge with murder instead. In fact, the United States did not have manslaughter on the books until the 20th century. England was the first country to indoctrinate manslaughter, and the United States was second.

paragraphs: A total of 12,658 murders were reported in 1999 in the U.S., including 1,903 without a specified reason, and 3,779 for which the reasons were unknown.

paragraphs: New York's status as the murder capital of the world improved during the 1990s. What follows are the number of murders for 1999:

paragraphs: Attempted murder is a crime. Attempted murder, or "attempt murder" in common law countries, also sometimes called "murder attempt", is when someone tries to kill another person. Just planning a murder is not enough. The act must come close to, but does not actually take the life of the other person.

paragraphs: It was punishable by death and the execution was carried out in Ancient Egypt, Ancient Mesopotamia, the Indus River Valley, Ancient Greece, The Roman Empire, and of course, China, which is by far the most populated country in the world, to this day. As with murder, attempted murder is a mortal sin to the Catholic Church.

paragraphs: The Roman Empire carried out about ten thousand executions, most if not all beheadings, during its time, and there is no doubt that many of these were those convicted of attempted murder.

paragraphs: "Assassination" is a word which means murdering a prominent person for a reason. The word is most used when the person who was killed was a celebrity or was a person involved in politics. The people who carry out assassinations are called "assassins" or "Hit-men". An assassin may murder someone for political reasons, for money, or for other reasons, such as favors owed and revenge. Assassination is the same as murder and is mortal sin to the Catholic Church.

paragraphs: The word "Assassin" comes from Hashishin, a Muslim group that was active in the Middle East from the 8th to the 14th centuries. This secret society killed people for political and religious reasons. It is thought that the assassins were under the influence of hashish and opium during their killings or during their training. The word "assassin" comes from either "hashashim", the influence of the drugs, or "hassansin", after their leader, Hassan-i Sabbah.

paragraphs: A murdersuicide is when a person kills someone else (murder), and then they kill themselves (suicide).

paragraphs: No one is tracking the number of murder–suicides in the United States. However, medical studies estimate between 1,000 and 1,500 deaths per year in the United States are murder-suicides.


title: Bird

paragraphs: Birds (Aves) are a group of vertebrates which evolved from dinosaurs. They are endothermic, with feathers.

paragraphs: Modern birds are toothless: they have beaked jaws. They lay hard-shelled eggs. They have a high metabolic rate, a four-chambered heart and a strong yet lightweight skeleton.

paragraphs: Birds live all over the world. They range in size from the 5 cm (2 in) bee hummingbird to the 2.70 m (9 ft) ostrich. They are the class of tetrapods with the most living species: about ten thousand. More than half of these are passerines, sometimes known as perching birds.

paragraphs: Birds are the closest living relatives of the Crocodilia. The fossil record shows that birds evolved from feathered theropod dinosaurs.

paragraphs: Modern birds are "not" descended from "Archaeopteryx". According to DNA evidence, modern birds (Neornithes) evolved in the Middle to Upper Cretaceous. More recent estimates, using a new way of calibrating molecular clocks, showed that modern birds originated early in the Upper Cretaceous. However, diversification occurred around the Cretaceous–Palaeogene extinction event.

paragraphs: The Cretaceous–Palaeogene extinction event 66 million years ago killed off all the non-avian dinosaur lines. Birds, especially those in the southern continents, survived this event and then migrated to other parts of the world.

paragraphs: Primitive bird-like dinosaurs are in the broader group Avialae. They have been found back to the mid-Jurassic period, around 170 million years ago. Many of these early "stem-birds", such as "Anchiornis", were not yet capable of fully powered flight. Many had primitive characteristics like teeth in their jaws and long bony tails.

paragraphs: Birds have wings which are more or less developed depending on the species. The only known groups without wings are the extinct moa and elephant birds. Wings, which evolved from forelimbs, gave birds the ability to fly. Later many groups evolved with reduced wings, such as ratites, penguins and many island species of birds. The digestive and respiratory systems of birds are also adapted for flight. Some bird species in aquatic environments, particularly seabirds and some waterbirds, have evolved as good swimmers.

paragraphs: Some birds, especially crows and parrots, are among the most intelligent animals. Several bird species make and use tools. Many social species pass on knowledge across generations, a form of culture. Many species annually migrate great distances. Birds are social. They communicate with visual signals, calls and bird songs. They have social behaviours such as cooperative breeding and hunting, flocking and mobbing of predators.

paragraphs: Most bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised by sexual reproduction. They are often laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching. Some birds, such as hens, lay eggs even when not fertilised, though unfertilised eggs do not produce offspring.

paragraphs: Many species of birds are eaten by humans. Domesticated and undomesticated birds (poultry and game) are sources of eggs, meat, and feathers. Songbirds, parrots and other species are popular as pets. Guano is harvested for use as a fertiliser. Birds figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational bird-watching is an important part of the ecotourism industry.

paragraphs: Birds come in a huge range of colours. These colours can be useful to a bird in two ways. Camouflage colours help to hide the bird, and bright colours identify the bird to others of the same species. Often the male is brightly coloured while the female is camouflaged.

paragraphs: Many birds are brown, green or grey. These colours make a bird harder to see; they camouflage the bird. Brown is the most common colour. Brown birds include: sparrows, emus, thrushes, larks, eagles and falcons and the female birds of many species such as: wrens, ducks, blackbirds and peafowls. When a brown bird is in long grass or among tree trunks or rocks, it is "camouflaged". Birds that live in long grass often have brown feathers streaked with black which looks like shadows. A bittern is almost invisible in long reeds. Other birds, including starlings and minahs, are quite dark in colour, but are flecked with little spots that look like raindrops on leaves. Bird may also camouflage their nests.

paragraphs: Many birds from hot countries are green or have some green feathers, particularly parrots. Birds that live in green trees often have green backs, even if they have bright-coloured breasts. From the back, the birds are camouflaged. This is very useful when sitting on a nest. The bird's bright-coloured breast is hidden. Budgerigars are bred in different colours such as blue, white and mauve, but in the wild, they are nearly all green and yellow. Even though they fly very well, they normally spend a lot of time on the ground, eating grass seeds. Their yellow and black striped back helps to hide them in the shadows made by long dry grass, while their green breasts are a similar colour to the leaves of gum trees.

paragraphs: Grey birds include most pigeons and doves, cranes, storks and herons. Grey birds are often rock-living birds like pigeons or birds that sit on dead tree trunks looking like a broken branch. Water birds like herons often have a pale grey colour which makes it harder for a fish to notice that the bird is standing, looking down for something to catch. Water birds, no matter what colour they are on top, are often white underneath, so that when a fish looks up, the bird looks like part of the sky.

paragraphs: Black birds include crows, ravens and male blackbirds. Some birds that are dark colours spend quite a lot of time on the ground, hopping around in the shadows under bushes. Among these birds are the male blackbird and the Satin Bowerbird which is not black but very dark blue. Crows and ravens often perch high on bare trees in the winter, where their black shape against the sky looks like the dark bare branches.

paragraphs: Many birds are not camouflaged, but stand out with vivid colours. They are usually male birds whose females are dull and camouflaged. The function of the colours is two-fold. First, the colours help them get mates, and second, the colours identify them to other males of the same species. Many birds are territorial, especially in the nesting season. They give out territory sounds and are easily seen. This lets other males know they will defend their territory. It sends out a "look elsewhere" signal to their competitors.

paragraphs: Some birds are famous for their colour and are named for it, such as the bluebird, the azure kingfisher, the golden pheasant, the scarlet macaw, the violet wren and the robin.

paragraphs: Many other birds are very brightly coloured, in countless combinations. Some of the most colourful birds are quite common, like pheasants, peacocks, domestic fowl and parrots. Colourful small birds include blue tits, the gold finches, humming birds, fairy wrens and bee eaters (which are also called rainbow birds). Some birds, like those of the bird of paradise in Papua New Guinea have such beautiful feathers that they have been hunted for them.

paragraphs: The peafowl is the best example of a display of colour to attract a mate. Also the male domestic fowl and junglefowl have long shiny feathers above his tail and also long neck feathers that may be a different colour to his wings and body. There are only a very few types of birds (like the eclectus parrot) where the female is more colourful than the male.

paragraphs: <nowiki>"Pied birds"</nowiki> are black and white. Black and white birds include magpies, pied geese, pelicans and Australian magpies (which are not really magpies at all). Pied birds often have brightly coloured beaks and legs of yellow or red. The silver pheasant, with its long white tail striped with fine bars of black, has a brightly coloured face.

paragraphs: Most birds can fly. They do this by pushing through the air with their wings. The curved surfaces of the wings cause air currents (wind) which lift the bird. Flapping keeps the air current moving to create lift and also moves the bird forward.

paragraphs: Some birds can glide on air currents without flapping. Many birds use this method when they are about to land. Some birds can also hover and remain in one place. This method is used by birds of prey such as falcons that are looking for something to eat. Seagulls are also good at hovering, particularly if there is a strong breeze. The most expert hovering birds are tiny hummingbirds which can beat their wings both backwards and forwards and can stay quite still in the air while they dip their long beaks into flowers to feed on the sweet nectar.

paragraphs: Different types of birds have different needs. Their wings are adapted to suit the way they fly.

paragraphs: Large birds of prey, such as eagles, that spend a lot of time soaring on the wind have wings that are large and broad. The main flight feathers are long and wide. They help the eagle to stay on rising air currents without using much energy, while the eagle looks at the ground below, to find the next meal. When the eagle sees some small creature move, it can close its wings and fall from the sky like a missile, opening its great wings again to slow down as it comes to land. The world's largest eagle, the Philippine eagle has a wingspan of about 2 m (6.7 ft) wide.

paragraphs: Birds that live in grassland areas or open forests and feed on fruit, insects and reptiles often spend a lot of time flying short journeys looking for food and water. They have wings that are shaped in a similar way to eagles, but rounder and not as good for soaring. These include many Australian birds like cockatoos.

paragraphs: Birds such as geese that migrate from one country to another fly very long distances. Their wings are big and strong, because the birds are large and they stock up on food for the long flight. Migrating water birds usually form family groups of 12-30 birds. They fly very high, making use of long streams of air that blow from north to south in different seasons. They are very well organised, often flying in a V pattern. The geese at the back do not have to flap so hard; they are pulled on by the wind of the ones at the front. Every so often, they change the leader so that the front bird, who does most work and sets the pace, can have a rest. Geese and swans are the highest-flying birds, reaching 8,000 metres or more when on migration. Geese often "honk" loudly while they are flying. It is thought that they do this to support the leader and help the young ones.

paragraphs: Birds that fly very quickly, such as swifts and swallows, have long narrow pointed wings. These birds need great speed because they eat insects, catching most of them while they are flying. These birds also migrate. They often collect in huge flocks of thousands of birds that move together like a whirling cloud.

paragraphs: Birds that live in bushes and branches have triangular wings that help the bird change direction. Many forest birds are expert at getting up speed by flapping and then gliding steadily among the trees, tilting to avoid things as they go. Members of the kingfisher family are expert at this type of flying.

paragraphs: Birds such as owls that hunt at night have wings with soft rounded feathers so that they do not flap loudly. Birds that are awake at night are called "nocturnal" birds. Birds that are awake during the day are "diurnal".

paragraphs: A wandering albatross and Arctic tern might spend several years without coming to land. They can sleep while gliding and have wings which, when they are stretched right out, look like the wings of a jet plane.

paragraphs: Bird like chickens that feed mainly on the ground and only use their wings to fly to safety have small wings.

paragraphs: Flocks of birds can be very highly organised in a way that takes care of all the flock members. Studies of small flocking birds like tree sparrows show that they clearly communicate with each other, as sometimes thousands of birds may fly in close formation and spiral patterns without colliding (or flying into each other).

paragraphs: Two common behaviours in flocking birds are guarding and reconnaissance. When a flock of birds is feeding it is common for one bird to perch on a high place to keep guard over the flock. In the same way, when a flock is asleep, often, one bird will remain awake. It is also common for large flocks to send one or two birds ahead of them when they are flying to a new area. The look-out birds can spy the lie of the land to find food, water and good places to perch.

paragraphs: Some birds do not fly. These include running birds like ostriches and emus and ocean-living birds, the large penguin family.

paragraphs: Ostriches and emus do not need to fly because although they feed and nest on the ground, their great size and their speed is their protection. Some other ground-feeding birds have not been so lucky. Some birds such as the dodo and the kiwi were ground-feeding birds that lived in safety on islands where there was nothing dangerous to eat them. They lost the power of flight. Kiwis are endangered because European settlement to New Zealand brought animals like cats, dogs and rats which kill kiwis and eat their eggs. However, kiwis and also the rare New Zealand ground parrot have survived. In the case of dodos, they were fat and delicious. They were killed and eaten by sailors until there was none left. Other flightless birds which have disappeared are the great auk and the moa.

paragraphs: Penguins spend a great deal of time at sea, where they are in danger from seals. On land, they usually live in areas where there were few dangers, until the arrival of European settlers with dogs and cats. Their wings have adapted to life in the sea and have become flippers which help them in swimming very fast.

paragraphs: Modern birds do not have teeth, and many swallow their prey whole. Nevertheless, they must break up food before it is digested. First of all, along their throat (oesophagus) they have a crop. This stores food items before digestion. That way a bird can eat several items, and then fly off to a quiet spot to digest them.

paragraphs: Their stomach comes next, with two very different parts. One part is like a straight hollow rod which secretes mild hydrochloric acid and an enzyme to break down protein. The other part of the stomach is the gizzard. This is muscular, and grinds up the contents. In herbivorous birds the gizzard contains some gastroliths (small stones or pieces of grit). Bones of fish will mostly be dissolved by the stomach acid. The partly digested and ground-up food now goes to the intestine, where digestion is completed, and most contents are absorbed. Anything indigestible, for example remains of feathers, is regurgitated via the mouth, not the cloaca.

paragraphs: The system is effective, and carnivorous birds can swallow quite large prey. A blue heron can swallow a fish as large as a carp successfully. Raptors eat by holding the prey down with a foot, and tearing it apart with their beak.

paragraphs: Although birds are warm-blooded creatures like mammals, they do not give birth to live young. They lay eggs as reptiles do, but the shell of a bird's egg is hard. The baby bird grows inside the egg, and after a few weeks hatches (breaks out of the egg).

paragraphs: Birds in cold climates usually have a breeding season once a year in the spring. Migratory birds can have two springs and two mating seasons in a year.

paragraphs: When the breeding season arrives, the birds choose partners. Some birds are mated for life, like married couples. These birds include pigeons, geese, and cranes. Other birds look for new partners each year and sometimes a male bird or cock will have several wives.

paragraphs: For birds that choose new mates, part of the breeding season is display. The male bird will do all sorts of things to attract females. These include singing, dancing, showing off the feathers and building a beautiful nest. Some male birds have splendid feathers for attracting females. The most famous is the peacock who can spread the feathers above his tail into a huge fan.

paragraphs: Once the birds have found partners, they find a suitable place to lay eggs. The idea of what is a suitable place differs between species, but most build bird nests. Robins will make a beautiful little round nest of woven grass and carefully line it with feathers, bits of fluff and other soft things. Swallows like to nest near other swallows. They make nests from little blobs of clay, often on a beam near the roof of a building where it is well sheltered. Many birds like a hollow tree to nest in. Eagle's nests are often just piles of dead wood on the top of the tallest tree or mountain. Scrub turkeys scratch together a huge pile of leaves that may be 10 metres across. Guillemots lay their eggs on rock shelves with no nest at all. Their eggs are shaped so that they roll around in circles and do not fall off cliffs. A cuckoo does not make its own nest. It lays its egg in the nest of another bird and leaves it for them to care for. The cuckoo eggs are camouflaged to look like the host's eggs.

paragraphs: When the nest has been prepared, the birds mate so that the eggs are fertilised and the chicks will start growing. Unlike mammals, birds only have one opening as the exit hole for body fluids, and for reproduction. The opening is called the cloaca. A female bird, called a hen, has two ovaries, of which the left one usually produces eggs.

paragraphs: Most male birds have no sex organs that can be seen. But inside the male are two testes which produce sperm which is stored in the cloaca. Birds mate by rubbing their cloacas together, although with some birds, particularly large water birds, the male has a sort of a penis inside the cloaca.

paragraphs: Once the hen has mated, she produces fertile eggs which have chicks growing inside them. She lays the eggs in the nest. There might be just one egg or a number of them, called a clutch. Emus might lay as many as fifteen huge dark green eggs in a clutch. After the eggs are laid, they are incubated, or kept warm so the chicks form inside. Most birds stay together for the whole nesting season, and one advantage is that the work is shared. Many birds take turns sitting on the eggs, so that each adult can feed.

paragraphs: This is not always the case. With emus, the male does all the sitting and all the baby-minding. With emperor penguins it is also the male that cares for the egg. There is only one egg, which he keeps on his feet and under his feathers, standing in a big group of males without feeding until the chick is hatched. While the eggs are hatching, the females are at sea, feeding, so that they can care for the chicks when they return.

paragraphs: Some birds put the eggs inside or on top of the mound of leaves and twigs. The mound acts like a compost heap. The decomposition of the rotting leaves causes the temperature to rise. This is heat released by the chemical action of bacterial and fungal respiration. It is the same reaction as that which keeps mammals and birds at a high temperature. The parents leave the mound. When the chicks hatch, they are able to feed themselves.

paragraphs: Many small birds take 2–4 weeks to hatch eggs. Albatrosses take 80 days. During this time the female loses a lot of her body weight.

paragraphs: The quickest hatching time is for the cuckoo. Some types of cuckoos take only 10 days. This means that when they hatch in the nest of their <nowiki>"foster parents"</nowiki>, the eggs that the parents have laid are not yet ready. Newborn cuckoos are naked, blind and ugly, but they are strong. They get under any eggs that are in the nest and throw them out before they hatch. That means that the cuckoo has the whole care of both parents. Baby cuckoos grow fast and often get bigger than the parents who feed them.

paragraphs: When baby birds hatch, in most types of birds, they are fed by both parents, and sometimes by older aunties as well. Their mouths are open all the time and are often very brightly coloured, which acts as a ''releaser<nowiki>"</nowiki>, a trigger which stimulates the parent to feed them. For birds that eat grain and fruit, the parents eat and partly digest the food for the babies. It is then vomited carefully into the baby's mouth.

paragraphs: Many birds, particularly those that mate for life, are very sociable and keep together in a family group which might be anything from 4 or 6 adult birds and their young to a very large flock.

paragraphs: As chicks grow they change the fluffy down that covers them as babies for real feathers. At this stage they are called fledglings. Other family members may help care for fledgling chicks, feeding them and protecting them from attack while parents are feeding. When the fledglings have their new feathers, they come out of the nest to learn to fly. In some types of birds, like pigeons, the parents watch over this and as the young ones get stronger, will give them flying lessons, teaching them how to glide, how to fly in spirals and how to land like an expert.

paragraphs: Most birds are social animals, at least part of the time. They communicate to each other using sounds and displays.

paragraphs: Almost all birds make sounds to communicate. The types of noises that vary greatly. Some birds can sing, and they are called songbirds or passerines. Examples are robins, larks, canaries, thrushes, nightingales. Corvids are passerines, but they do not sing. Birds that are not songbirds include: pigeons, seagulls, eagles, owls and ducks. Parrots are not songbirds, even though they can be taught to sing human songs.

paragraphs: All birds make noises (<nowiki>"bird vocalisation"</nowiki>), but not all sing. Songbirds are passerines, many of which have beautiful melodic songs. Songs have different functions. Danger cries are different from territorial songs and mating calls are a third type. Fledgling may also have different calls from adults. Recognition calls for partners are quite common.

paragraphs: As to where the song comes from, there are three kinds of species:

paragraphs: Most singing birds that are kept as pets, like canaries, have several tunes and some variations.

paragraphs: The same species of bird will sing different songs in different regions. A good example of this is the currawong. This is an Australia bird which is like a black and white crow. In the autumn, families get together in large flocks and do a lot of singing. Currawongs from some areas sing much more complex songs than others. Generally, currawongs from the Blue Mountains are the finest singers. The song of the currawong can be sung as a solo, but is often performed as a choir. One bird will take the lead and sing "Warble-warble-warble-warble!" All the other birds will join in and sing "Wooooooo!". When all the birds know the song, the choir will sing the "Warble" part and the soloist will sing the "Woo!". The song changes from year to year and from place to place.

paragraphs: The Austrian naturalist Konrad Lorenz studied the way in which birds communicate, or talk to each other. He found that each type of bird had a number of sounds which they made automatically, when ever they felt a certain way. Every sound had an action that went with it. So, if the bird was frightened, it acted frightened and made a frightened sound. This told the other birds around it that something frightening was happening.

paragraphs: If a flock of birds were flying over a field, they would be calling "Fly! Fly!" But a hungry bird, seeing something good to eat down below might start calling "Food! Food!" If other birds were also hungry, they would make the same call until more birds were calling "Food! Food!" than "Fly! Fly!". At this point, the mind of the flock would be changed. Some of the birds would start to yell "Fly downwards! Fly downwards!" as they sank from the sky, until the whole flock was all noisily calling the same thing.

paragraphs: These communication sounds are often short hard sounds like: chirps, squeaks, squawks and twitters. Sometimes the calls are longer and more musical. They include the "Rookety-coo" sound of a pigeon and the "Cockadoodledoo!" of a rooster. The bird cannot change these sounds. They always make them in the same way. The bird is locked into making each sound every time a particular idea comes into its head. The connection between how they feel and how they call is innate: they are born with it. Some calls in some species are learnt. Then, it is the tendency to learn which is inherited.

paragraphs: Konrad Lorenz noticed that when birds sing, they often use a lot of their regular calls as part of the song. Lorenz had a flock of jackdaws which were scattered during World War II. One day, an old bird returned. For many months she sat on the chimney singing her song, but in the song she kept making the call which Lorenz knew meant "Come home! Come home!" One day, to the great surprise of Lorenz, a male bird flew from a passing flock and joined her on the chimney. Lorenz was sure that it was her long-lost "husband" who had found his way home at last.

paragraphs: Palaeontologists have found some exceptional places (lagerstätten) where fossils of early birds are found. The preservation is so good that on the best examples impressions of their feathers can be seen, and sometimes even the remains of meals they have eaten. From these remains we know that birds evolved from small carnivorous dinosaurs (theropods) in the Jurassic period. They radiated into a huge variety in the Lower Cretaceous. At the same time, their direct competitors, the pterosaurs, dwindled in numbers and variety, and became extinct at the end of the Mesozoic.

paragraphs: Birds are classified by taxonomists as 'Aves' (Avialae). Birds are the only living descendants of dinosaurs (strictly speaking, they "are" dinosaurs). Birds and Crocodilia are the only living members of the once-dominant Archosaur reptiles.

paragraphs: The class Aves is now defined as all the descendants of the most recent common ancestor of modern birds and "Archaeopteryx lithographica".

paragraphs: "Archaeopteryx", from the Upper Jurassic (some 150–145 million years ago), is the earliest bird which could fly. It is famous, because it was one of the first important fossils found after Charles Darwin published his ideas about evolution in the 19th century. By modern standards, "Archaeopteryx" could not fly very well. Other early fossil birds are, for example, "Confuciusornis", "Anchiornis huxlei" and other Paraves.

paragraphs: Many fossils of early birds and small dinosaurs have been discovered in the Liaoning Province of Northeast China. The fossils show that most small theropod dinosaurs had feathers. These deposits have preserved them so well that the impressions of their feathers can be clearly seen. This leads us to think that feathers evolved first as heat insulation and only later for flight. The origin of birds lies in these small feathered dinosaurs.

paragraphs: Palaeontologists now agree that birds evolved from Maniraptora group of dinosaurs. This explains why one might say birds are living dinosaurs.

paragraphs: Some birds are eaten as food. Most usually it is the chicken and its eggs, but people often also eat geese, pheasants, turkeys and ducks. Other birds are sometimes eaten are: emus, ostriches, pigeons, grouse, quails, doves, woodcocks and even songbirds. Some species have died out because they have been hunted for food, for example the dodo and the passenger pigeon.

paragraphs: Many species have learned how to get food from people. The number of birds of these species has grown because of it. Seagulls and crows find food from garbage dumps. The feral pigeon ("Columba livia"), sparrows ("Passer domesticus" and starlings ("Sturnus vulgaris") live in large numbers in towns and cities all over the world.

paragraphs: Sometimes people also use working birds. For example, homing pigeons carry messages. Nowadays people sometimes race them for sport. People also use falcons for hunting, and cormorants for fishing. In the past, people in mines often used a canary to see if there were bad gas methane in the air.

paragraphs: People often have colorful birds such as parrots and mynahs as pets. These intelligent birds are popular because they can copy human talking. Because of this, some people trap birds and take them to other countries to sell. This is not usually allowed these days. Most pet birds are specially bred and are sold in pet shops.

paragraphs: People can catch some bird diseases, for example: "psittacosis", "salmonellosis", "campylobacteriosis", Newcastle's disease, "mycobacteriosis", influenza, "giardiasis" and "cryptosporiadiosis". In 2005, there was an epidemic of bird influenza spreading through some parts of the world, often called avian flu.

paragraphs: Some people have birdboxes in their gardens to give birds a place to nest and bird tables where birds can get food and water in very cold or very dry weather. This lets people see some small birds close up which are normally hidden away in bushes and trees.

paragraphs: A report produced by BirdLife International every five years measures the population of birds worldwide. In 2018 the number of bird species has decreased by 40%. One in every eight types of birds is now almost extinct.


title: Freedom of speech

paragraphs: Most people think freedom of speech is necessary for a democratic government. In countries without free speech, people might be afraid to say what they think. Then, the government does not know what the people want. If the government does not know what they want, it cannot respond to their wants. Without free speech, the government does not have to worry as much about doing what the people want. Some people say this is why some governments do not allow free speech: they do not want to be criticised, or they fear there would be revolution if everyone knew everything that was happening in the country.

paragraphs: A well-known liberal thinker, John Stuart Mill, believed that freedom of speech is important because the society that people live in has a right to hear people's ideas. It's not just important because everyone should have a right to express him or herself.

paragraphs: Few countries with "free speech" let everything be said. For example, the United States Supreme Court said that it was against the law to shout "fire" in a crowded theater if there is no fire, because this might cause people to panic. The International Covenant on Civil and Political Rights also says that it is not okay to cause national, racial or religious hatred. Also, some countries have laws against hate speech.

paragraphs: As Tocqueville pointed out, people may be hesitant to speak freely not because of fear of government punishment but because of social pressures. When an individual announces an unpopular opinion, he or she may face the disdain of their community or even be subjected to violent reactions. While this type of suppression of speech is even more difficult to prevent than government suppression is, there are questions about whether it truly falls within the ambit of freedom of speech, which is typically regarded as a legal right to be exercised against the government, or immunity from governmental action.


title: Banana

paragraphs: A banana is the common name for a type of fruit and also the name for the herbaceous plants that grow it. These plants belong to the genus "Musa". They are native to the tropical region of southeast Asia.

paragraphs: It is thought that bananas were grown for food for the first time in Papua New Guinea. Today, they are cultivated in tropical regions around the world. Most banana plants are grown for their fruits, which botanically are a type of berry. Some are grown as ornamental plants, or for their fibres.

paragraphs: There are about 110 different species of banana. In popular culture and commerce, "banana" usually refers to the soft and sweet kind, also known as "dessert bananas". Other kinds, or cultivars, of banana have a firmer, starchier fruit. Those are usually called plantains. Plantains are mostly used for cooking or fibre.

paragraphs: Other than being used as food, beer can be made by fermenting the juice of certain cultivars in Africa, known as "beer bananas". The ash of bananas can be used to make soap. In Asia, bananas are often planted to provide shade to plants that like shade, for example coffee, cocoa, nutmeg or black pepper. Because of this, banana plants can often be found in plantations of other crops.

paragraphs: The banana plant is the largest herbaceous flowering plant. Banana plants are often mistaken for trees. Bananas have a "false stem" (called "pseudostem"), which is made by the lower part of the leaves. This pseudostem can grow to be two to eight meters tall. Each pseudostem grows from a corm. A pseudostem is able to produce a single bunch of bananas. After fruiting, the pseudostem dies and is replaced. When most bananas are ripe, they turn yellow or, sometimes, red. Unripe bananas are green.

paragraphs: Banana leaves grow in a spiral and may grow long and wide. They are easily torn by the wind, which results in a familiar, frayed look.

paragraphs: The banana fruits grow from a banana blossom in hanging clusters, also called a "bunch" or "banana stem". The fruits grow in rows called "tiers" or "hands". There can be as many as twenty fruits to a hand, and as many as twenty tiers in a bunch. A bunch usually weighs between 30 and 50 kilograms (65 to 110 pounds).

paragraphs: A single fruit weighs about 125 grams (4.4 ounces) on average; about three quarters of this is water.

paragraphs: Each banana (or "finger") has a protective outer layer (called "peel" or "skin"). There is a fleshy part inside that readily spilts into three segments. It is the only known tri-segmented fruit in the world. Both the skin and inner part can be eaten. Western cultures generally eat the inside raw and throw away the skin. Some Asian cultures eat both the skin and the inside cooked. Each fruit has many "strings" that run between the skin and the inner part.

paragraphs: Bananas have a lot of vitamin B, vitamin C, and potassium.

paragraphs: Bananas are grown in at least 107 countries. The banana species growing in the wild have fruits with many hard, large seeds, but almost all bananas grown to be eaten have seedless fruits. Bananas are classified either as dessert bananas or as green cooking bananas. Almost all export bananas are of the dessert types. Only about ten to fifteen percent of all production is for export. Dessert bananas change their color and usually turn yellow, when they are ripe; plantains and bananas generally used for cooking stay green. Certain bananas have other colors when ripe.

paragraphs: The countries that produce the most bananas include India, Brazil, China, Ecuador and the Philippines. The top five countries that exported bananas were Ecuador, Costa Rica, the Philippines, Colombia and Guatemala. The United States, the European Union and Japan buy the most bananas. Bananas are among the most valuable agricultural export products; They provided about sixty percent of export earnings of Saint Lucia and about twelve percent of the Gross Domestic Product of the country, between 1994 and 1996.

paragraphs: Some people are allergic to bananas. There are two basic forms of these allergies. The first is known as oral allergy syndrome. Within an hour of eating a banana, swelling starts inside the mouth or throat. This allergy is related to allergies caused by pollen, like that of the birch tree. The other is similar to latex allergies. It causes urticaria and potentially serious upper gastrointestinal symptoms.

paragraphs: The fibre gained from the banana plant has been used to make textiles for a long time. In Japan, bananas have been grown to be used for clothing and in the house since at least the 13th century. In the Japanese system, the leaves and shoots are cut from the plant periodically to make sure they are soft. The harvested shoots must first be boiled in lye to prepare the fibres for the making of the yarn. These banana shoots produce fibres of varying degrees of softness. They can be used for yarns and textiles of different qualties, and for specific uses. For example, the outermost fibres of the shoots are the coarsest - they are good for tablecloths. The softest innermost fibres are desirable for kimono and kamishimo. This traditional Japanese banana cloth making process has many steps, all performed by hand.

paragraphs: Another system is used in Nepal. There the trunk of the banana plant is harvested instead. Small pieces of this trunk are then softened. The fibres are extracted mechanically, bleached, and dried. They are then sent to the Kathmandu Valley, where high-end rugs are produced. These rugs have a texture and general qualities similar to that of silk. These banana fibre rugs are woven by traditional Nepalese hand-knotted methods.

paragraphs: A medium-sized banana will provide around 320-400 mg of potassium, which meets about 10% of your daily potassium needs. Potassium helps your body maintain a healthy heart and blood pressure. In addition, bananas are low in sodium. The low sodium and high potassium combination helps to control high blood pressure.

paragraphs: Banana fiber is also used to make "banana paper". There are two different kinds of banana paper: paper made from the bark, and paper made from the fibre and from unused fruits.


title: Biel/Bienne, Switzerland

paragraphs: Biel/Bienne (official name; "Biel" is German, "Bienne" is French) is an industrial town in Switzerland. It is in the part of Switzerland named Bern and near the city also named Bern. The town is known for many companies that make watches and machines.

paragraphs: The town of Biel, the capital of Swiss watch-making, lies at the end of Lake Biel, at the foot of the Jura Hills in the Lake Region.

paragraphs: The wonderful old town with its town church and its location as the gateway to the three Jura lakes (Lakes Biel, Lake Neuchâtel and Lake Murten) with vineyards on the hillsides and extensive vegetable cultivation make the town very attractive.

paragraphs: Biel is the only town in Switzerland in which German and French are spoken side by side We can feel the relaxed mentality here coming from the mixture of these three languages.

paragraphs: Biel was awarded the Wakker Prize in 2004 by the Swiss Heritage Society for the way it conserved its 20th century buildings, especially the ‘new construction’ from the 1920s and 30s.

paragraphs: Swatch, Rolex, Omega, Tissot, Movado and Mikron all come from this town. But Biel has also become important in the field of other industries and in communication.

paragraphs: It is possible to travel on various routes along the lakes on passenger boats in summer. The day trip through all three Jura lakes is especially popular. Of course there are all types of water sports on Lake Biel.

paragraphs: The town of Biel was built by the Prince-Bishop of Bale between 1220 and 1230. The old town is the smallest part of Biel with only . Most buildings there still look as in the 18th century. The biggest part of the old town is without any traffic. There aren’t any big stores or industries or any big companies. Each Saturday there is a market. The castle, “the ring” and the theatre are very popular. The town church is on the “Ringplatz” and was built between 1451 and 1470.There they burned the witches in the 18th century. From the 6 medieval city gates only one and two towers survived.

paragraphs: The entire town of Biel is part of the Inventory of Swiss Heritage Sites. Several individual buildings in the old town have also been protected for their cultural heritage.

paragraphs: The Reformed City Church is one of the most important late-Gothic buildings in the Canton of Bern. The church has a main floor, two second floors and four small chapels. There are some wall-paintings in the church. Most windows are among the oldest ones in Switzerland. The church was first written about in an index in 1228. After a horrible fire in the old town the church was destroyed. It was rebuilt between 1367 and 1451. The town church got on a new organ on 6th November 2011. The church was closed for more than half a year to put the new organ in and to improve the inside of the church. It cost about 1,74 million Swiss francs. The old organ was sent to Poland.

paragraphs: About 57% of the people in Biel speak German as their mother tongue. The remaining 43% speak French as their mother tongue. That is why the city has two names.


title: Swatch Internet Time

paragraphs: Swatch Internet Time is a way to measure time invented in 1998 by the Swatch manufacturing firm in Biel/Bienne, Switzerland. Time is shown as an "@" mark with three numerals. The day starts with @000 for midnight. Noon is @500. Just before midnight is @999. The thousand parts which make up a day are called "dot beats" (.beats). Each dot beat is one minute and 26.4 seconds long. Midnight is the same as Central European Winter Time (UTC+1)and Internet Time is the same all over the world. It does not change during the Summer. People can use it to plan phone calls or Internet meetings. Most types of Linux can show Internet Time as the desktop clock.


title: Test tube

paragraphs: A test tube is a kind of laboratory glassware, composed of a fingerlike length of glass tubing, open at the top, usually with a rounded lip at the top, and a rounded 'U' shaped bottom.

paragraphs: They range in size from a couple inches to several inches long, from a few millimeters to a couple centimeters in diameter. They are designed to allow easy heating of samples, to be held in a flame, and often are made of expansion-resistant glasses, such as borosilicate glass (known by brand-names such as Pyrex and Kimax).

paragraphs: Tests tubes are often preferred above beakers when multiple small chemical or biological samples have to be handled and/or stored.

paragraphs: Vacutainers are a type of test tube that can be used for both collection and storage of blood.


title: Beaker

paragraphs: A beaker is a kind of laboratory glassware. A beaker is a cylinder with a lip and a spout (a bend in the rim of the beaker which makes it easier to pour liquids without spilling any). A beaker is usually about the same width as its height. This makes beakers very stable and easy to handle. They may be made of plastic, glass, or borosilicate glass. Some beakers have marks on them to show about how much volume of liquid they hold - these can not be used for exact measurements.

paragraphs: Beakers are often used to make solutions and they are probably the most used piece of laboratory glassware.


title: Crucible

paragraphs: In chemistry, a crucible is a kind of laboratory equipment that is usually a small cup, about the size of a shot glass, made of porcelain or non-reactive metal. Crucibles are used to heat chemical compounds to very high temperatures using a gas burner. One of the earliest uses of platinum was as a material in crucibles. Metals such as nickel and zirconium are also used as a modern crucible material.


title: Lithium

paragraphs: Lithium (from Greek "lithos" 'stone') is a soft, silver-white metal with symbol Li. It is the third chemical element in the periodic table. This means that it has 3 protons in its nucleus and 3 electrons around it. Its atomic number is 3. Its mass number is 6.94. It has two common isotopes, Li and Li. Li is more common. 92.5% of lithium is Li. Lithium is a soft silvery metal that is very reactive. It is used in lithium batteries and certain medicines.

paragraphs: Lithium is one of the alkali metals. Lithium is a silvery solid metal (when freshly cut). It is very soft. Thus it can be cut easily with a knife. It melts at a low temperature. It is very light, similar to wood. It is the least dense metal and the least dense element in a solid or liquid state. It can hold more heat than any other solid element. It conducts heat and electricity easily.

paragraphs: It will react with water, giving off hydrogen to form a basic solution (lithium hydroxide). Because of this, lithium must be stored in petroleum jelly. Sodium and potassium can be stored in oil but lithium cannot because it is so light. It will just float on the oil and not be protected by it.

paragraphs: Lithium also reacts with halogens. It can react with nitrogen gas to make lithium nitride. It reacts with air to make a black tarnish and then a white powder of lithium hydroxide and lithium carbonate.

paragraphs: Lithium forms chemical compounds with only one oxidation state: +1. Most of them are white and unreactive. They make a bright red color when heated in a flame. They are a little toxic. Most of them dissolve in water. Lithium carbonate is less soluble in water than the other alkali metal carbonates like sodium carbonate.

paragraphs: It does not occur as an element in nature. It only is in the form of lithium compounds. The ocean has a large amount of lithium in it. Certain granites have large amounts of lithium. Most living things have lithium in them. There are some places where much lithium is in the salt. Some silicates have lithium in them.

paragraphs: Lithium (Greek "lithos", meaning "stone") was discovered by Johann Arfvedson in 1817. In 1818, Christian Gmelin observed that lithium salts give a bright red color in flame. W.T. Brande and Sir Humphrey Davy later used electrolysis on lithium oxide to isolate the element. Lithium was first used in greases. Then nuclear weapons became a big use of lithium. Lithium was also used to make glass melt easier and make aluminium oxide melt easier in making aluminium. Now lithium is used mainly in batteries.

paragraphs: It was apparently given the name "lithium" because it was discovered from a mineral, while other common alkali metals were first discovered in plant tissue.

paragraphs: It is made by getting lithium chloride from pools and springs. The lithium chloride is melted and electrolyzed. This makes liquid lithium and chlorine.

paragraphs: Its main use is in batteries. Lithium is used as an anode in the lithium battery. It has more power than batteries with zinc, like alkaline cells. Lithium ion batteries also have lithium in them, though not as an element. It is also used in heat transfer alloys. Lithium is used to make organolithium compounds. They are used for very strong bases.

paragraphs: It is used to make special glasses and ceramics, including the Mount Palomar telescope's 200 inch mirror. Lithium is the lightest known metal and can be alloyed with aluminium, copper, manganese, and cadmium to make strong, lightweight metals for aircraft.

paragraphs: Lithium compounds are used in some drugs known as mood stabilizers. Lithium niobate is used in radio transmitters in cell phones. Some lithium compounds are also used in ceramics. Lithium chloride can absorb water from other things. Some lithium compounds are used to make soap and grease. Lithium carbonate is used as a drug to treat manic depression disorder. Lithium carbonate is used for the treatment of bipolar disease and other mental illness conditions.

paragraphs: Organolithium compounds are used to make polymers and fine chemicals. Many lithium compounds are used as reagents to make organic compounds. Some lithium compounds like lithium aluminium hydride, lithium triethylborohydride, n-butyllithium and tert-butyllithium are commonly used as very strong bases called superbases.

paragraphs: Lithium compounds are used as pyrotechnic colorants and oxidizers in red fireworks and flares. Lithium chloride and lithium bromide are used as desiccants for gas streams. Lithium hydroxide and lithium peroxide are used to remove carbon dioxide and purify the air in spacecrafts and submarines. Lithium hydroxide, lithium peroxide and lithium perchlorate are used in oxygen candles that supply submarines with oxygen.

paragraphs: Lithium aluminum hydride can also be used as a solid fuel by itself. Lithium hydride that contains lithium-6 is used in thermonuclear weapons.

paragraphs: Lithium reacts with water, making irritating smoke and heat. It is not as dangerous as the other alkali metals. Lithium hydroxide is very corrosive.

paragraphs: There are 5 isotopes of Lithium having respectively 2, 3, 4, 5 and 6 neutrons in the nucleus. The most common isotope in nature is Li which makes up 92.58 % of the total. The second isotope which is widely available is Li which makes up 7.42 % of the total. The other 3 isotopes exist in very small quantities. The atomic mass of Lithium is 6.939.


title: Beryllium

paragraphs: Beryllium is in group 2 of the periodic table, so it is an alkaline earth metal. It is grayish (slightly gray) in color. It has an atomic number of 4 and is symbolized by the letters Be. It is toxic and should not be handled without proper training.

paragraphs: Beryllium has 4 electrons, 4 protons, and 5 neutrons.

paragraphs: Beryllium has one of the highest melting points of the light metals: 1560 K (1287 °C). It is added to other metals to make stronger alloys. Beryllium-copper alloy is used in tools because it does not make sparks.

paragraphs: At standard temperature and pressure, beryllium resists oxidation when exposed to oxygen.

paragraphs: Beryllium is best known for the chemical compounds it forms. Beryllium combines with aluminium, silicon and oxygen to make a mineral called beryl. Emerald and aquamarine are two varieties of beryl which are used as gemstones in jewelry.

paragraphs: Since it has a very high stiffness to weight ratio, beryllium is used to make the diaphragms in some high-end speakers.

paragraphs: Beryllium is used to make jet aircrafts, guided missiles, spacecraft, and satellites, including the James Webb telescope. Beryllium can reflect neutrons, and thin foils of beryllium are sometimes used in nuclear weapons as the outer layer of the plutonium pits. Beryllium is also used in fuel rods for CANDU reactors. Beryllium is used to make many dental alloys.

paragraphs: It is a relatively rare element in the universe. It usually occurs when larger atomic nuclei have split up. In stars, beryllium is depleted because it is fused and builds larger elements.


title: Data compression

paragraphs: Data compression is a set of steps for packing data into a smaller space, while allowing for the original data to be seen again. Compression is a two-way process: a compression algorithm can be used to make a data package smaller, but it can also be run the other way, to decompress the package into its original form. Data compression is useful in computing to save disk space, or to reduce the bandwidth used when sending data (e.g., over the internet).

paragraphs: Lossless compression packs data in such a way that the compressed package can be decompressed, and the data can be pulled out exactly the same as it went in. This is very important for computer programs and archives, since even a very small change in a computer program will make it unusable.

paragraphs: This type of compression works by reducing how much waste space is in a piece of data. For example, if you receive a data package which contains "AAAAABBBB", you could compress that into "5A4B", which has the same meaning but takes up less space. This type of compression is called "run-length encoding", because you define how long the "run" of a character is. In the above example, there are two runs: a run of 5 A's, and another of 4 B's.

paragraphs: The problem with run-length encoding is that it only works on long pieces of the same value of data. If you receive a package with "ABBAABAAB" inside, that can be compressed into "1A2B2A1B2A1B"; but that's longer than the original! In this case, there's another method that can be used: checking how often a particular value comes up in the whole data package. This is often called frequency compression.

paragraphs: The most common kind of frequency compression is called Huffman coding, after the scientist who came up with the idea. The basic plan is to give each distinct value in a piece of data a code:- values that crop up all the time get shorter codes, and values that only show up once or twice get longer codes.

paragraphs: For some types of data, lossy compression can go much further; this is most often the case with media files, like music and images. Lossy compression loses some of the data so that there's less to store. Depending on what information is lost, people do not notice it is missing. As a result, it can simply be removed from the data.

paragraphs: Of course, this will not work for computer programs and other such data where every piece is important; throwing away pieces of a computer program is generally unhealthy for the program.


title: Compiler

paragraphs: A compiler is a computer program that translates computer code written in one programming language into another programming language. The first language is called the source language, and the code is called source code. The second language is called the target and can usually be understood by computers. In that case, the instructions become machine code.

paragraphs: If a compiler can convert the same instruction text into machine code for different computers (like smartphones or video game machines), it is a 'cross-compiler'. If the compiler can make instruction text that is easier for people to read, it is a 'de-compiler'. People who write these instructions are called programmers. Some even made programs that can translate the instructions that describe how a compiler should work, into a compiler. That kind of program is called a compiler-compiler.

paragraphs: A compiler usually has three steps. It reads the text and makes notes about how the words and sentences go together. If the words don't make sense, it will try to tell the programmer. Then it will use what it knows about the target language to make the instructions fit better. It then writes down the instructions in the target language. If the source instructions are on different pages, it may have to compile several before it can write everything down.

paragraphs: The first piece, a lexical analyzer, reads a page of instruction text and splits it into words and sentences. It also marks the type for each word. For example, a word may be number, a variable, a verb, a math sign, or an adjective. The output of a lexical analyzer is a list of tokens.

paragraphs: A parser reads in the output of the lexical analyzer, and verifies the syntax of the language. If the input program is syntactically incorrect or has a type error, it generates errors and warnings. This is called semantic analysis. For example, the parser might complain about the example above, if it "had not" already seen codice_3 with its type adjective. The parser uses all the information to make a structure typically called an Abstract Syntax Tree (AST).

paragraphs: The next piece, an optimizer rearranges the tree structure so the target language is optimized. 'Optimized' includes using fewer instructions to perform the same work. This could be important if the final program needs to check a lot of data. (Like seeing how many people, in the whole country, are fifty years old "and" buy medicine.) An 'optimized' result might also mean breaking long instructions into smaller ones. Unused and unaccessible code will be removed at this step.

paragraphs: A programmer usually tries to write instructions in small, related groups. That way, they can keep track of fewer changes in the program. But, that means the code may go on several pages. When a compiler sees that the target program uses several pages to explain the whole recipe, it may use a linker. The linker will put instructions that say where to find the code that's next. Finally, the compiler writes down the instructions in the target language.

paragraphs: Programmers who write compiler code try to make it as perfect as possible. If the programmer writes incorrect code, the compiler informs of them an error, but if the compiler code itself contains errors, it may be hard to tell where exactly the problem lies.

paragraphs: At the end of each compilation step the partial finished product could be stored and then only processed later on. A language like Java uses this successfully, where they lack the final translation step to instructions the processor understands. They only do the final translation step once the Java program is running on a computer. This is either called "interpreting" or "JIT"ting, depending on the technique used.

paragraphs: For example, the source code might contain an equation, such as "x = 5*10 ". The lexical analyzer would separate each number and symbol (such as "*" or "+") into separate tokens. The parser would note the pattern of tokens, as being an equation. The intermediate-code generator would write a form of coding which defines a storage variable named "x" and assigns the numerical product of 5*10 plus 6 and 1. The optimizer would simplify the calculation, of 5*10+6+1, as being just 57. Hence, the target machine-code generator would set a variable named "x" and put the value 57 into that storage place in the computer's memory, using the instructions of whichever computer chip is being used.


title: Eye

paragraphs: The eye is a round organ for sensing light so organisms can see. It is the first part of the visual system. About 97 percent of animals have eyes. Image-resolving eyes are present in cnidaria, molluscs, vertebrates, annelids and arthropods.

paragraphs: In mammals, two kinds of cells, "rods" and "cones", allow sight by sending signals through the optic nerve to the brain.

paragraphs: Some animals can see light that humans cannot see. They can see ultraviolet or infrared light.

paragraphs: The "lens" on the front part of the eye acts like a camera lens. It can be pulled flatter by muscles inside the eye, or allowed to become rounder. As some people get older, they may not be as able to do this perfectly. Many people are born with other small problems or get them later in life, and they may need eyeglasses (or "contact lenses") to fix the problem.

paragraphs: Like different cameras, different eyes have different abilities. They may have higher or lower resolution, the ability to detect small details. They may have different performance in low light; nocturnal animals can see better at night than daytime animals. They may have different ability to distinguish colors.

paragraphs: The human eye is composed of several different parts. These parts may or may not be the same in other animals. They are:

paragraphs: Today, ten different types of eyes are known. Most ways of capturing an image have evolved at least once.

paragraphs: One way to categorize eyes is to look at the number of "chambers". "Simple eyes" are made of only one concave chamber, perhaps with a lens. Compound eyes have many such chambers with their lenses on a convex surface.

paragraphs: Eyes also can be grouped according to how the photoreceptor is made. Photoreeptors are either cillated, or rhabdomic. and some annelids possess both.

paragraphs: Pit eyes are set in a depression in the skin. This reduces the angles at which light can enter. It allows the organism to say where the light is coming from.

paragraphs: Such eyes can be found in about 85% of phyla. They probably came before the development of more complex eyes. Pit eyes are small. They are made of up to about hundred cells, covering about 100 µm. The directionality can be improved by reducing the size of the opening, and by putting a reflective layer behind the receptor cells.

paragraphs: The pinhole eye is an advanced form of pit eye. It has several bits, most notably a small aperture and deep pit. Sometimes, the aperture can be changed. It is only found in the "Nautilus". Without a lens to focus the image, it produces a blurry image. Consequently, nautiloids can not discriminate between objects with a separation of less than 11°. Shrinking the aperture would produce a sharper image, but let in less light.

paragraphs: The resolution of pit eyes can be improved a lot by adding a material to make a lens. This will reduce the radius of the blurring, and increase the resolution that can be achieved. The most basic form can still be seen in some gastropods and annelids. These eyes have a lens of one refractive index. It is possible to get a better image with materials that have a high refractive index which decreases towards the edges. This decreases the focal length and allows a sharp image to form on the retina.

paragraphs: This eye creates an image that is sharp enough that motion of the eye can cause significant blurring. To minimize the effect of eye motion while the animal moves, most such eyes have stabilizing eye muscles.

paragraphs: The ocelli of insects have a simple lens, but their focal point always lies behind the retina.They can never form a sharp image. This limits the function of the eye. Ocelli (pit-type eyes of arthropods) blur the image across the whole retina. They are very good at responding to rapid changes in light intensity across the whole visual field — this fast response is accelerated even more by the large nerve bundles which rush the information to the brain. Focusing the image would also cause the sun's image to be focused on a few receptors. These could possibly be damaged by the intense light; shielding the receptors would block out some light and reduce their sensitivity.

paragraphs: This fast response has led to suggestions that the ocelli of insects are used mainly in flight, because they can be used to detect sudden changes in which way is up (because light, especially UV light which is absorbed by vegetation, usually comes from above).

paragraphs: The eyes of most land-living vertebrates (as well as those of some spiders, and insect larvae) contain a fluid that has a higher refractive index than the air. The cornea is sharply curved and refracts light towards the focus. The lens need not do all of the refracting. This lets the lens adjust the focus more easily, for much higher resolution.

paragraphs: Instead of using a lens it is also possible to have cells inside the eye that act like mirrors. The image can then be reflected to focus at a central point. This design also means that someone looking into such an eye will see the same image as the organism which has them.

paragraphs: Many small organisms such as rotifers, copeopods and platyhelminthes use such this design, but their eyes are too small to produce usable images. Some larger organisms, such as scallops, also use reflector eyes. The scallop "Pecten" has up to 100 millimeter-scale reflector eyes fringing the edge of its shell. It detects moving objects as they pass successive lenses.

paragraphs: Compound eyes are different from simple eyes. Instead of having one organ that can sense light, they put together many such organs. Some compound eyes have thousands of them. The resulting image is put together in the brain, based on the signals of the many eye units. Each such unit is called "ommatidium", several are called "ommatidia". The ommatidia are located on a convex surface, each of them points in a slighly different direction. Unlike simple eyes, compound eyes have a very large angle of view. They can detect fast movement, and sometimes the polarization of light.

paragraphs: Compound eyes are common in arthropods, annelids, and some bivalved molluscs.

paragraphs: The evolution of eyes started with simplest light-sensitive patches in unicellular organisms. These eye-spots do nothing but detect if the surroundings are light or dark. Most animals have a biochemical 'clock' inside. These simple eye-spots are used to adjust this daily clock, which is called circadian rhythm. Some snails, for example, see no image (picture) at all, but they sense light, which helps them stay out of bright sunlight.

paragraphs: More complex eyes have not lost this function. A special type of cells in the eye senses light for a different purpose than seeing. These cells are called "ganglion" cells. They are located in the retina. They send their information about light to the brain along a different path (the "retinohypothalamic tract"). This information adjusts (synchronizes) the animal's circadian rhythm to nature's light/dark cycle of 24 hours. The system also works for some blind people who cannot see light at all.

paragraphs: Eyes that are a little bit better are shaped like cups, which lets the animal know where the light is coming from.

paragraphs: More complex eyes give the full sense of vision, including color, motion, and texture. These eyes have a round shape that makes light rays focus on the back part of the eye, called the "retina".

paragraphs: Good fliers like flies or honey bees, or prey-catching insects like praying mantis or dragonflies, have specialized zones of ommatidia organized into a fovea area which gives sharp vision. In this zone the eyes are flattened and the facets are larger. The flattening allows more ommatidia to receive light from a spot. This gives a higher resolution.

paragraphs: The body of "Ophiocoma wendtii", a type of brittle star, is covered with ommatidia, turning its whole skin into a compound eye. The same is true of many chitons.


title: Tongue-twister

paragraphs: A tongue-twister is a phrase that is hard to say. They often use alliteration and homophones. They are commonly employed to help warm up singers and actors


title: AbiWord

paragraphs: AbiWord is a free word processor that can be downloaded for free, it is open source and is much smaller in size than a proprietary alternative, Microsoft Word. It is available for FreeBSD, Linux, Microsoft Windows, Mac OS X, and QNX. Its mascot is Abi the ant. It is much smaller than many other commercial word-processors of its time, only using about 15Mb on a computer's hard drive under Microsoft Windows. It is easy to use.