1365 résultats pour "timée"
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Relativity - astronomy.
beta, for example, might be as large as 0.5, and the mass of the electron doubled. The mass of a rapidly moving electron could be easily determined by measuring thecurvature produced in its path by a magnetic field; the heavier the electron, the greater its inertia and the less the curvature produced by a given strength of field ( see Magnetism). Experimentation dramatically confirmed Einstein's prediction; the electron increased in mass by exactly the amount he predicted. Thus, the kinetic ener...
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Relativity
I
INTRODUCTION
Albert Einstein
In 1905 German-born American physicist Albert Einstein published his first paper outlining the theory of relativity.
in calculating very large distances or very large aggregations of matter. As the quantum theory applies to the very small, so the relativity theory applies to the verylarge. Until 1887 no flaw had appeared in the rapidly developing body of classical physics. In that year, the Michelson-Morley experiment, named after the American physicistAlbert Michelson and the American chemist Edward Williams Morley, was performed. It was an attempt to determine the rate of the motion of the earth through t...
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Sun - astronomy.
A The Sun’s Place in the Milky Way The Milky Way Galaxy contains about 400 billion stars. All of these stars, and the gas and dust between them, are rotating about a galactic center. Stars that arefarther away from the center move at slower speeds and take longer to go around it. The Sun is located in the outer part of the galaxy, at a distance of 2.6 × 10 17 km (1.6 × 10 17 mi) from the center. The Sun, which is moving around the center at a velocity of 220 km/s (140 mi/s), takes 250 million y...
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Television.
A charge-coupled device (CCD) can be much smaller than a camera tube and is much more durable. As a result, cameras with CCDs are more compact and portablethan those using a camera tube. The image they create is less vulnerable to distortion and is therefore clearer. In a CCD, the light from a scene strikes an array ofphotodiodes arranged on a silicon chip. Photodiodes are devices that conduct electricity when they are struck by light; they send this electricity to tiny capacitors. Thecapacitors...
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Aerospace Medicine - astronomy.
medically as aeroembolism and popularly as the bends, leads to confusion, paralysis, or neurocirculatory collapse. The most characteristic symptoms of the bends arepain in the large joints resulting from pressure of the gas on tendons and nerves, together with spasm of the blood vessels. Preflight inhalation of pure oxygen toeliminate nitrogen from the system has proved valuable as a preventive measure. Rapid decompression, resulting from accidental failure at high altitudes of thepressure withi...
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Lemieux Scores Eight Points.
Lemieux tied five all-time Stanley Cup records: Eight points in one game, set by Patrik Sundstrom of the New Jersey Devils in 1988Four points in one period, accomplished 11 times (as of 1996)Five goals in one game, set by Philadelphia's Reggie Leach (1976), Darryl Sittler of the Toronto Maple Leafs (1976), and Newsy Lalonde (1919) and MauriceRichard (1944) of the Montréal CanadiensFour goals in the first period, set by Philadelphia's Tim Kerr in 1985Three assists in one period, accomplished 62...
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Butcher Wins the Iditarod.
Butcher's winning streak ended in 1989 when she finished in second place, 65 minutes behind Joe Runyan. She was back on top a year later, gliding down FrontStreet two hours ahead of Runyan. A boisterous crowd of Nome locals greeted Butcher with sirens and banners. Her time of 11 days 1 hour 53 minutes sliced 13hours off the course record she had set in 1986. Conditions for the 1990 race were particularly unforgiving. The 70 mushers contended with the deepest snow in 25 years, several unseaso...
- Anglais: Writing time
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Michael Jordan.
playoffs the Bulls pushed the Pistons to seven games in the Eastern Conference Finals before losing again. As he grew older, Jordan made a concerted effort to help his teammates reach their own potential. The result of his renewed commitment to team-oriented play was theBulls’ first NBA championship title. After the 1990-91 season the Bulls swept the Pistons in the Eastern Conference Finals and then defeated the Los Angeles Lakers inthe NBA Finals. Jordan won the league MVP award for the second...
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Michael Jordan
I
INTRODUCTION
Michael Jordan, born in 1963, American professional basketball player, considered by many to be the greatest player in basketball history.
playoffs the Bulls pushed the Pistons to seven games in the Eastern Conference Finals before losing again. As he grew older, Jordan made a concerted effort to help his teammates reach their own potential. The result of his renewed commitment to team-oriented play was theBulls’ first NBA championship title. After the 1990-91 season the Bulls swept the Pistons in the Eastern Conference Finals and then defeated the Los Angeles Lakers inthe NBA Finals. Jordan won the league MVP award for the second...
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Banking.
loans, and some commercial loans in addition to checking accounts and time deposits. Credit unions, SLAs, and savings banks help encourage thriftiness by paying interest to consumers who put their money in savings deposits. Consequently, creditunions, SLAs, and savings banks are often referred to as thrift institutions. Of the various types of banks in the United States, commercial banks account for the greatest single source of the financial industry’s assets. In 2000 the 8,528commercial banks...
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Articles of Confederation - U.
trade, or any other pretence whatever. VIII ARTICLE IV The better to secure and perpetuate mutual friendship and intercourse among the people of the different states in this union, the free inhabitants of each of thesestates, paupers, vagabonds and fugitives from Justice excepted, shall be entitled to all privileges and immunities of free citizens in the several states; and the people ofeach state shall have free ingress and regress to and from any other state, and shall enjoy therein all the...
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Jupiter (planet) - astronomy.
Beneath the supercritical fluid zone, the pressure reaches 3 million Earth atmospheres. At this depth, the atoms collide so frequently and violently that the hydrogenatoms are ionized—that is, the negatively charged electrons are stripped away from the positively charged protons of the hydrogen nuclei. This ionization results in asea of electrically charged particles that resembles a liquid metal and gives rise to Jupiter’s magnetic field. This liquid metallic hydrogen zone is 30,000 to 40,000 k...
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Sleep - biology.
V FUNCTIONS OF SLEEP Although no one knows for sure why we sleep, there are a number of theories. Sleep may have evolved to protect animals from their predators by reducing theiractivity during the times when they are most vulnerable. Research has shown that REM and NREM sleep may serve specific biological functions. Sleep deprivation studies reveal that humans and other animals respond to sleeploss in the same way. When study subjects are deprived of REM sleep, they tend to spend longer period...
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Islam.
commanded to face the Kaaba, an ancient shrine in the city of Mecca. The Qur’an also refers to the recitation of parts of the Qur’an as a form of prayer. However, evenwith its numerous references, the Qur’an alone does not give exact instructions for this central ritual of prayer. The most detailed descriptions of the rituals for prayer derive from the example set by the prophet Muhammad and are preserved in later Islamic traditions. Somedetails of these rituals vary, however all Muslims agree t...
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William Shakespeare
I
INTRODUCTION
William Shakespeare (1564-1616), English playwright and poet, recognized in much of the world as the greatest of all dramatists.
Shakespeare’s reputation today is, however, based primarily on the 38 plays that he wrote, modified, or collaborated on. Records of Shakespeare’s plays begin toappear in 1594, when the theaters reopened with the passing of the plague that had closed them for 21 months. In December of 1594 his play The Comedy of Errors was performed in London during the Christmas revels at Gray’s Inn, one of the London law schools. In March of the following year he received payment for two playsthat had been per...
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William Shakespeare.
Shakespeare’s reputation today is, however, based primarily on the 38 plays that he wrote, modified, or collaborated on. Records of Shakespeare’s plays begin toappear in 1594, when the theaters reopened with the passing of the plague that had closed them for 21 months. In December of 1594 his play The Comedy of Errors was performed in London during the Christmas revels at Gray’s Inn, one of the London law schools. In March of the following year he received payment for two playsthat had been per...
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Sigmund Freud.
reminiscences from the past and about her daydreams. Remarkably, as her narrative revisited memories from the past, which were associated with the onset of aparticular symptom, each symptom disappeared when accompanied by an emotional outburst. Breuer made use of this discovery to eliminate her symptoms one at atime. He called the treatment the cathartic technique (from the Greek katharsis meaning “purgation”). The treatment was time consuming and required considerable effort to reach dimly re...
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Ice Hockey.
Each period begins with a face-off at the blue dot at center ice. During the face-off one player from each team lines up at the dot with the stick blade on the ice. After the referee drops the puck, the two players attempt to gain possession of it. Quick hands and strength are essential qualities for players participating in the face-off. Once the puck is dropped, it is in play until an official’s whistle stops it, a goal is scored, or time expires. The team on offense tries to move the puck f...
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Comet - astronomy.
may exceed the planet Jupiter in size, however. Observations from telescopes on Earth and in space indicate that most of the gases in the coma and tail of a comet are fragmentary molecules, or radicals, of the mostcommon elements in space: hydrogen, carbon, nitrogen, and oxygen. The radicals, for example, of CH, NH, and OH may be broken away from the stable molecules CH 4 (methane), NH 3 (ammonia), and H 2O (water), which may exist as ices or more complex, very cold compounds in the nucleus. Al...
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Arithmetic
I
INTRODUCTION
Arithmetic, branch of mathematics that arises from counting, the most basic mathematical operation.
Subtract the units: 6 - 3 = 3. Then subtract the tens column: 6 – 2 = 4. The results of these two single-digit subtractions, written side by side, provide the answer: Subtraction is a bit more complicated if we need to subtract a larger digit from a smaller one. For example, when subtracting 47 from 92, the units value (7) of 47 isgreater than the units value (2) of 92. We can handle this situation using a procedure called borrowing, which is like carrying in reverse. Ten units can be borrowe...
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Horse Racing.
interested parties claim the same horse at the same price, lots are drawn to determine the winning offer. Knowledgeable owners and trainers may use claiming races toobtain, at bargain prices, horses whose former owners underestimated the potential of their animals. Two other types of contests are match races and walkovers. A match race pits only two horses, almost always that season’s most successful racers, in a head-to-headduel. A walkover occurs when only one horse has not been scratched (w...
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Abortion.
Intact dilation and extraction, also referred to as a partial birth abortion, consists of partially removing the fetus from the uterus through the vaginal canal, feet first,and using suction to remove the brain and spinal fluid from the skull. The skull is then collapsed to allow complete removal of the fetus from the uterus. III SOCIAL AND ETHICAL ISSUES Abortion has become one of the most widely debated ethical issues of our time. On one side are pro-choice supporters—individuals who favor a...
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le travail
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1996 Summer Olympics.
jump, the first African woman ever to win an Olympic field event. In the first Olympic women's soccer competition, the United States returned to world prominence with a 2-1 gold medal victory over China before more than 76,000spectators—believed to be the largest crowd in history for a women's sporting event. The U.S. team won the first women's World Cup in 1991, defeating Norway inthe final match, but had failed to defend the title in 1995 when they lost to the Norwegians in the semifinals...
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baudelaire analyse L'ennemi
Baudelaire highlighting the time that passes through a progression from the past to the present, the discouraging record of this stormy youth is underlined by the past composed «on fait» (vers 3) and by the proposition of consequence to the present. The metaphor continues in the mention of a nature which has undergone the meteorological elements in their destructive character, the past having left traces: a life ravaged by «le tonnerre et la pluie», by the blows of fate and the daily g...
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Change
shape of a thing does not count as intrinsic on the above criterion since having shape is, arguably, not logically independent of the existence of the containing space. An alternative means of strengthening the Cambridge criterion employs the notion of causality. A genuine change in an object must, on this account, involve causal consequences contiguous to the object. This is not true of, for example, becoming an aunt or becoming famous - the effects of such 'changes' need not be near the obje...
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Judaism.
is learned or memorized”), the earliest document of rabbinic literature, edited in Palestine at the turn of the 3rd century. Subsequent rabbinic study of the Mishnah inPalestine and Babylonia generated two Talmuds (“that which is studied”; also called Gemera, an Aramaic term with the same meaning; see Talmud), wide-ranging commentaries on the Mishnah. The Babylonian Talmud, edited about the 6th century, became the foundation document of rabbinic Judaism. Early rabbinic writings also include exe...
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Democratic Party.
At the beginning of the 20th century the Democrats’ minority position among voters remained central to their existence. The Progressive split in Republican rankshelped elect Woodrow Wilson twice, but the entry of the United States into World War I ended that. The war, popular at first, backfired against the Wilsonadministration when large numbers of German Americans and Irish Americans protested with their votes against U.S. involvement on England’s side. The result wasanother Republican landsli...
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Franklin D.
Roosevelt entrusted his campaign management to the journalist Louis McHenry Howe. Howe, a genius at politics, performed brilliantly. Henceforth, Roosevelt and Howewere to be almost inseparable, and Howe, a wizened and colorful little man, guided the political fortunes of the Hyde Park aristocrat. B Assistant Secretary of the Navy Even before his reelection to the New York legislature, Roosevelt had entered the national political arena by taking part in the campaign of Governor Woodrow Wilson of...
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Franklin D.
Roosevelt entrusted his campaign management to the journalist Louis McHenry Howe. Howe, a genius at politics, performed brilliantly. Henceforth, Roosevelt and Howewere to be almost inseparable, and Howe, a wizened and colorful little man, guided the political fortunes of the Hyde Park aristocrat. B Assistant Secretary of the Navy Even before his reelection to the New York legislature, Roosevelt had entered the national political arena by taking part in the campaign of Governor Woodrow Wilson of...
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Timée - étude - Platon
PERRIN Paul TD2 Résumé du texte 7a Les éléments sont des corps en profondeur. Ils sont composés de formes géométriques. Ces formes géométriques sont des triangles divisibles en deux, la droite sécante offrant nécessairement deux angles droits au deux triangles dessinés. Le démiurge crée le monde ainsi en connaissance de cause, et tenant les hommes en « ami é », il leur a fait don de raison afin qu’ils puissent comprendre la composi on des éléments. Le corps élémentaire dans sa nature...
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Supreme Court of the United States.
The Constitution does not specify formal qualifications for membership on the Supreme Court. From the beginning, though, justices have all been lawyers, and mostpursued legal and political careers before serving on the Court. Many justices served as members of Congress, governors, or members of the Cabinet. One president,William Howard Taft, was later appointed chief justice. Some justices came to the Court from private law practice, and others were appointed from positions as lawprofessors. Man...
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Civil Rights and Civil Liberties.
A Religious Freedom Although religious freedom has not generally been curtailed in the United States, Roman Catholics, Jews, and members of such unconventional Protestant groups as theOneida Community and the Church of Jesus Christ of Latter-day Saints have historically been discriminated against and sometimes have even been persecuted,although today overt discrimination has almost vanished. The federal Civil Rights Act of 1964, as well as many state and local laws, prohibits religious discrimi...
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Collectibles and Collecting.
common blond and thus commands a higher price. If there are different variations to a collectible, the least common one is usually worth more. Often there areinteresting stories behind rarities, such as the highly sought-after 1909 Honus Wagner baseball card. At that time tobacco companies manufactured and distributedbaseball cards, and when the antitobacco Wagner complained, his card was pulled from production. Very few copies in good condition have ever been found. C Age Age is often an indic...
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Rome (Italy) - geography.
country’s best, and in the summer at the Baths of Caracalla. The city also has some 20 theaters and 6 major concert halls, which offer a varied repertory during the fall,winter, and spring. The museums of the city deal with all aspects of the arts and sciences and are among the world’s finest. The oldest art collection in Rome, housed in the CapitolineMuseum, was established in 1471 and contains exceptional antiquities. Among other Roman museums are the National Museum of the Villa Giulia, which...
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Babe Ruth's "Called Shot".
When Ruth, the second New York batter in the fifth inning, came to the plate, Wrigley Field was roaring. “They called me ‘big belly’ and ‘baboon,’” Ruth recalled,according to the book Great Moments in American Sports by Jerry Brondfield. The New York Times said of the Chicago fans, “It seems decidedly unhealthy for anyone to taunt the great man Ruth too much, and very soon the crowd was to learn its lesson.” During the at bat, Ruth mouthed off to the Chicago players in thedugout as they and...
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Galileo
I
INTRODUCTION
Galileo (1564-1642), Italian physicist and astronomer who, with German astronomer Johannes Kepler, initiated the scientific revolution that flowered in the work of
English physicist Sir Isaac Newton.
V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...
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Galileo.
V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...
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Supernova - astronomy.
The term hypernova has been proposed for an extremely massive core-collapse supernova—possibly more than 100 times the mass of the Sun. A hypernova is thought to form a black hole. Just before it explodes, a hypernova may release a huge burst of gamma rays in a jet from the rotating black hole at its center. These jets mayexplain the so-called long gamma-ray bursts detected by astronomers. According to some researchers, massive stars with over 40 solar masses may sometimescollapse directly int...
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Aging - biology.
Different theories have been proposed to explain how SF works. One theory is based on the assumption that aging, and diseases that occur more frequently withadvancing age, are caused by structural damage to cells. This damage accumulates in tiny amounts each time the cell divides, eventually preventing the cell fromcarrying out normal functions. One cause of this damage may be free radicals, which are chemical compounds found in the environment and also generated by normal chemical reactions in...
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Criminal Punishment.
In the United States and Canada, younger offenders may be sentenced to highly regimented, military-style correctional programs known as boot camps. Generally,offenders volunteer to participate in boot camp programs to avoid other types of incarceration. At boot camps, officials subject offenders to strict discipline and physicaltraining. They also provide educational or vocational programs. Boot camps serve as an alternative to traditional, long-term incarceration and attempt to train offenderst...
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Electronic Games.
arcade game of all time. With Pizza Time Theaters legitimizing the idea of arcades and hits such as Ms. Pac-Man , Asteroids , Donkey Kong , Tempest , Frogger , and Defender bringing new excitement to gaming, the coin-operated video game business boomed. In 1981 Americans spent 75,000 person-years and $5 billion playing video games at anestimated 4,300 arcades in the United States. Many popular arcade games also were translated for use on the Atari 2600 and its chief rivals in the homemarket—M...
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Cosmology - astronomy.
In 1917 American scientist Harlow Shapley measured the distance to several groups of stars known as globular clusters. He measured these distances by using amethod developed in 1912 by American astronomer Henrietta Leavitt. Leavitt’s method relates distance to variations in brightness of Cepheid variables, a class of starsthat vary periodically in brightness. Shapley’s distance measurements showed that the clusters were centered around a point far from the Sun. The arrangement of theclusters was...
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Fire - chemistry.
were usually natural caves. Eventually people learned to dip branches in pitch to form torches. They created crude lamps by filling a hollowed out piece of stone withmoss soaked in oil or tallow (a substance derived from animal fat). By cooking with fire, prehistoric people made the meat of the animals they killed more palatable and digestible. They learned to preserve meat by smoking it over a fire,vastly decreasing the danger of periodic starvation. Cooking also enabled them to add some for...
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History of Astronomy - astronomy.
Egypt, the Sun was directly overhead at noon. On the same date and time in Alexandria, Egypt, the Sun was about 7 degrees south of zenith. With simple geometryand knowledge of the distance between the two cities, he estimated the circumference of the Earth to be 250,000 stadia. (The stadium was a unit of length, derivedfrom the length of the racetrack in an ancient Greek stadium. We have an approximate idea of how big an ancient Greek stadium was, and based on that approximationEratosthenes was...
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Marriage.
In many traditional societies, marriage typically involved transfers of property from the parents to their marrying children or from one set of parents to the other. Thesecustoms persist in some places today and are part of the tradition of arranged marriages. For example, in some cultures the bride’s parents may give property (knownas a dowry) to the new couple. The practice of giving dowries has been common in countries such as Greece, Egypt, India, and China from ancient times until thepresen...
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Mesoamerica.
for cooking. In other regions, the earliest ceramics are more sophisticated technically and aesthetically. At around 1800 BC in the Pacific coastal region of Soconusco (in what is now southeastern Chiapas State, Mexico), the earliest pottery was very complex both in forms and decoration. It seems to have had a social function and beenused primarily for ritual feasting. III MAJOR CIVILIZATIONS Over a period of 3000 years, beginning in about 1500 BC, a number of important cultures emerged in M...
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Telescope - astronomy.
Observatory). In some telescopes designed in the 1990s, the mirror’s weight has been dramatically reduced by sandwiching a honeycomb pattern of glass ribs between a thin, butrigid, concave mirror and a flat back plate. Engineers have even developed meniscus mirrors—mirrors that are too thin to support their own weight. An adjustableframework supports the meniscus mirror, and servomechanical actuators, controlled by computer, continually adjust the shape of the mirror as it tracks celestial tar...
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Industrial Revolution
I
INTRODUCTION
Industrial Revolution, widespread replacement of manual labor by machines that began in Britain in the 18th century and is still continuing in some parts of the world.
The most important advance in iron production occurred in 1784 when Englishman Henry Cort invented new techniques for rolling raw iron, a finishing process thatshapes iron into the desired size and form. These advances in metalworking were an important part of industrialization. They enabled iron, which was relativelyinexpensive and abundant, to be used in many new ways, such as building heavy machinery. Iron was well suited for heavy machinery because of its strength anddurability. Because of t...