190 résultats pour "measure"

• Western Philosophy.

  the popular belief in personal deities, but he failed to explain the way in which the familiar objects of experience could develop out of elements that are totally differentfrom them. Anaxagoras therefore suggested that all things are composed of very small particles, or “seeds,” which exist in infinite variety. To explain the way in whichthese particles combine to form the objects that constitute the familiar world, Anaxagoras developed a theory of cosmic evolution. He maintained that the activ...

• Statistics I INTRODUCTION Statistics, branch of mathematics that deals with the collection, organization, and analysis of numerical data and with such problems as experiment design and decision making.

  Professional pollsters typically conduct their surveys among sample populations of 1,000 people. Statistical measurementsshow that reductions in the margin of error flatten out considerably after the sample size reaches 1,000.© Microsoft Corporation. All Rights Reserved. The raw materials of statistics are sets of numbers obtained from enumerations or measurements. In collecting statistical data, adequate precautions must be taken tosecure complete and accurate information. The first problem of...

• 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...

• Exercise.

  broad, and most studies suggest a positive relationship between physical fitness and mental achievement. The relationship between regular aerobic exercise and cardiovascular health and longevity is well established. Regular exercise leads to a reduction in the risk ofcoronary heart disease, in which fatty deposits (plaque) form in blood vessels supplying the muscular wall of the heart, compromising oxygen delivery to the heartmuscle. In addition, with regular exercise the efficiency of the heart...

• Electron I INTRODUCTION Models of the Atom Once scientists discovered the electron, they set out to explain how electrons behave in atoms.

  Electron Density and Orbital ShapesAtomic orbitals are mathematical descriptions of where the electrons in an atom (or molecule) are most likely to be found.These descriptions are obtained by solving an equation known as the Schrödinger equation, which expresses ourknowledge of the atomic world. As the angular momentum and energy of an electron increases, it tends to reside indifferently shaped orbitals. The orbitals corresponding to the three lowest energy states are s, p, and d, respectively....

• Benin - country.

  French is the official language of Benin, but most people speak an African language. Each of the country’s ethnic groups has its own language. Fon is the most widelyspoken language. About 52 percent of the population professes traditional religious beliefs, chiefly Vodun, a belief in spirits. Arab merchants introduced Islam to the region, and today it isthe religion of some 20 percent of the people, most of whom live in the north. Christianity, especially Roman Catholicism, is the religion of ab...

• Astronomy - astronomy.

  Telescopes may use either lenses or mirrors to gather visible light, permitting direct observation or photographic recording of distant objects. Those that use lenses arecalled refracting telescopes, since they use the property of refraction, or bending, of light ( see Optics: Reflection and Refraction ). The largest refracting telescope is the 40-in (1-m) telescope at the Yerkes Observatory in Williams Bay, Wisconsin, founded in the late 19th century. Lenses bend different colors of light by d...

• John Diefenbaker.

  only Conservative elected from Saskatchewan, which had gone solidly to the Co-operative Commonwealth Federation (CCF), a coalition party dedicated to social andwelfare reforms. In 1952 the Liberals in Saskatchewan abolished Diefenbaker's Lake Centre seat altogether by merging it with the neighboring legislative district of Moose Jaw, where theCCF had a vast majority. In 1953 Diefenbaker decided to run for election in Prince Albert. Again he was the only Conservative returned to Parliament fromSa...

• John Diefenbaker - Canadian History.

  only Conservative elected from Saskatchewan, which had gone solidly to the Co-operative Commonwealth Federation (CCF), a coalition party dedicated to social andwelfare reforms. In 1952 the Liberals in Saskatchewan abolished Diefenbaker's Lake Centre seat altogether by merging it with the neighboring legislative district of Moose Jaw, where theCCF had a vast majority. In 1953 Diefenbaker decided to run for election in Prince Albert. Again he was the only Conservative returned to Parliament fromSa...

• Greenhouse Effect.

  addition, humans cut down huge tracts of trees for lumber or to clear land for farming or building. This process, known as deforestation, can both release the carbonstored in trees and significantly reduce the number of trees available to absorb carbon dioxide. As a result of these human activities, carbon dioxide in the atmosphere is accumulating faster than Earth’s natural processes can absorb the gas. By analyzing airbubbles trapped in glacier ice that is many centuries old, scientists have d...

• Diabetes Mellitus.

  Once diabetes is diagnosed, treatment consists of controlling the amount of glucose in the blood and preventing complications. Depending on the type of diabetes, thiscan be accomplished through regular physical exercise, a carefully controlled diet, and medication. Individuals with Type 1 diabetes must receive insulin, often two to four times a day, to provide the body with the hormone it does not produce. Insulin cannot be takenorally, because it is destroyed in the digestive system. Consequent...

• James Madison.

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• James Madison

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• James Madison - USA History.

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• Glacier.

  covered. In spring the snow cover begins to melt in the lower reaches, exposing the ice surface. As temperatures increase, the melting moves up the glacier. Thesnowline is the highest position the melting reaches during the year. Firn is old granular snow. The firn limit may not exactly coincide with the annual snowline since insome years rapid melting leaves behind firn patches below the snowline. Some glaciers exhibit features called ice streams and icefalls. Ice streams are valley glaciers th...

• Swimming.

  the swimmer and the pinky finger should enter the water first. At the same time, the swimmer moves the left arm through the water below the left side of the body.Once in the water, the right arm begins pulling the swimmer forward by bending at the elbow. At the same time the swimmer holds the left arm straight as it reachesthe hip and lifts it out of the water. As the right arm continues to pull, the swimmer rotates slightly onto the right side and swings the left arm up above the head. As the s...

• Venezuela - country.

  Venezuela has six navigable rivers. Of the thousand or more streams in the country, the majority flow into the Orinoco. The Orinoco flows east across central Venezuelaand drains approximately four-fifths of the total area of the country. With the tributaries—the Apure, Meta, and Negro rivers—it forms the outlet into the Atlantic Oceanfor the waters of much of the interior of Colombia, as well as of inland Venezuela. F Climate The climate of Venezuela is tropical on the Llanos and along the coas...

• Space Exploration - astronomy.

  to produce 250,000 newtons (56,000 lb) of thrust. The Germans launched thousands of V-2s carrying explosives against targets in Britain and The Netherlands. Whilethey did not prove to be an effective weapon, V-2s did become the first human-made objects to reach altitudes above 80 km (50 mi)—the height at which outer spaceis considered to begin—before falling back to Earth. The V-2 inaugurated the era of modern rocketry. A2 Early Artificial Satellites During the years following World War II, the...

• Federal Republic of Germany - country.

  B Rivers and Lakes Rivers have played a major role in Germany’s economic development. The Rhine River flows in a northwesterly direction from Switzerland through much of westernGermany and The Netherlands into the North Sea. It is a major European waterway and a pillar of commerce and trade. Its primary German tributaries include theMain, Mosel, Neckar, and Ruhr rivers. The Oder (Odra) River, along the border between Poland and Germany, runs northward and empties into the Baltic; it provides an...

• Labor Unions in Canada - Canadian History.

  job. Before collective bargaining begins, workers elect a bargaining committee. The bargaining committee determines the workers’ demands and strategy innegotiations with the employer. Local unions usually are part of national or international unions. These national and international unions employ a staff for organizing workers at the local level, doingresearch, educating union members about labor and political matters, and working with local union leaders. Unions hold regular conventions of dele...

• American Revolution.

  C1 The South Southern agriculture was founded on the cultivation of tobacco, wheat, and corn in Virginia, Maryland, and North Carolina, and of rice and indigo (a blue dye) in SouthCarolina and Georgia. There was a large demand for these crops in Europe. These crops were cultivated with the help of black slaves imported from Africa. The whiteplanter class in the South was the most powerful, both politically and economically. C2 The North Wheat was the main cash crop of the mid-Atlantic colonies...

• American Revolution - U.

  C1 The South Southern agriculture was founded on the cultivation of tobacco, wheat, and corn in Virginia, Maryland, and North Carolina, and of rice and indigo (a blue dye) in SouthCarolina and Georgia. There was a large demand for these crops in Europe. These crops were cultivated with the help of black slaves imported from Africa. The whiteplanter class in the South was the most powerful, both politically and economically. C2 The North Wheat was the main cash crop of the mid-Atlantic colonies...

• Population.

  year AD 1, and it took more than 1,500 years to reach the 500 million mark. Growth was not steady but was marked by oscillations dictated by climate, food supply, disease, and war. Starting in the 17th century, great advances in scientific knowledge, agriculture, industry, medicine, and social organization made possible rapid acceleration inpopulation growth. Machines gradually replaced human and animal labor. People slowly acquired the knowledge and means to control disease. By 1900 the worldp...

• Geology.

  terminology. Today the geologic time scale is generally agreed upon and used by scientists around the world, dividing time into eons, eras, periods, and epochs. Everyfew years, the numerical time scale is refined based on new evidence, and geologists publish an update. Geologists use several methods to determine geologic time. These methods include physical stratigraphy, or the placement of events in the order of their occurrence,and biostratigraphy, which uses fossils to determine geologic time...

• 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...

• American Civil War.

  free state to keep the balance in the Senate. It also provided that slavery would be excluded from the still unorganized part of the Louisiana Territory. A line was drawnfrom Missouri’s southern boundary, at the latitude of 36°30’, and slavery would not be allowed in the territory north of that line,with the exception of Missouri. B Compromise of 1850 Agitation against slavery continued in the North. The South reacted by defending it ever more strongly. The Mexican War, by which the United Stat...

• American Civil War - U.

  free state to keep the balance in the Senate. It also provided that slavery would be excluded from the still unorganized part of the Louisiana Territory. A line was drawnfrom Missouri’s southern boundary, at the latitude of 36°30’, and slavery would not be allowed in the territory north of that line,with the exception of Missouri. B Compromise of 1850 Agitation against slavery continued in the North. The South reacted by defending it ever more strongly. The Mexican War, by which the United Stat...

• Molecule - chemistry.

  attracted to the negatively charged electrons between them. The electrons belong to the molecule as a whole. However, each hydrogen atom now has a complete outershell of two electrons. The formula H 2 describes a hydrogen molecule, a discrete unit. When a molecule contains just two atoms, such as the hydrogen molecule does, it is called a diatomic molecule. Some atoms can form covalent bonds with more than one other atom and thus create a larger molecule. Atoms form molecules with covalent bo...

• Thermodynamics I INTRODUCTION Thermodynamics, field of physics that describes and correlates the physical properties of macroscopic systems of matter and energy.

  Carnot EngineThe idealized Carnot engine was envisioned by the French physicist Nicolas Léonard Sadi Carnot, who lived during theearly 19th century. The Carnot engine is theoretically perfect, that is, it converts the maximum amount of energy intomechanical work. Carnot showed that the efficiency of any engine depends on the difference between the highest andlowest temperatures reached during one cycle. The greater the difference, the greater the efficiency. An automobileengine, for example, wou...

• Air Pollution.

  Several pollutants attack the ozone layer. Chief among them is the class of chemicals known as chlorofluorocarbons (CFCs), formerly used as refrigerants (notably in airconditioners), as agents in several manufacturing processes, and as propellants in spray cans. CFC molecules are virtually indestructible until they reach thestratosphere. Here, intense ultraviolet radiation breaks the CFC molecules apart, releasing the chlorine atoms they contain. These chlorine atoms begin reacting withozone, br...

• Rutherford B.

  Governor Hayes gave Ohio an honest administration. During his two separate terms (from 1868 to 1872 and then from 1876 to 1877) were conspicuous, in that age ofpolitical corruption, for freedom from scandal and irregularities. Even newspapers that supported the opposition Democratic Party praised his administration. Although a Democratic legislature in Hayes's first term obstructed many of his liberal measures, he was able to reform the prison system. During his second term aRepublican majority...

• Martin Van Buren.

  political ambitions. The Clintonians cited as one example of Van Buren's unscrupulous methods his support of a convention in 1821 to revise the state's constitution. Van Buren and hisBucktails said they wanted to make the constitution more democratic. The Clintonians retorted that the real aim was to oust them from office. Both sides were right. Therevised constitution introduced a needed extension of voting rights and improved the operation of the state government. However, it also removed many...

• Martin Van Buren

  political ambitions. The Clintonians cited as one example of Van Buren's unscrupulous methods his support of a convention in 1821 to revise the state's constitution. Van Buren and hisBucktails said they wanted to make the constitution more democratic. The Clintonians retorted that the real aim was to oust them from office. Both sides were right. Therevised constitution introduced a needed extension of voting rights and improved the operation of the state government. However, it also removed many...

• Planetary Science - astronomy.

  III ORIGINS AND COMPOSITIONS OF PLANETS Astronomers believe that planetary systems are formed of elemental materials that were created in the interiors of giant stars. Some of this material comes from giantstars that shed material into space as they age. Most of the matter to form planets, however, comes from stars that explode as supernovas and spread debris enrichedwith the heavier chemical elements into space. According to the currently accepted views, the most likely first stage in the evo...

• Latin American Independence.

  be inferior and were not permitted a university education. In the lowest caste were the African slaves. As the Spanish monarchy tried to increase its authority, it was hampered by the power of the Catholic Church. The church, including various religious orders, hadacquired great wealth, including large holdings of land, in the colonies. The Jesuit order especially had gained extraordinary wealth and political influence, and it alsocontrolled much of the university and high school education in th...

• Egypt - country.

  Egypt has a wide variety of mineral deposits, some of which, such as gold and red granite, have been exploited since ancient times. The chief mineral resource ofcontemporary value is petroleum, found mainly in the Red Sea coastal region, at Al ‘Alamayn (El ‘Alamein) on the Mediterranean, and on the Sinai Peninsula. Otherminerals include phosphates, manganese, iron ore, and uranium. Natural gas is also extracted. D Plants and Animals The vegetation of Egypt is confined largely to the Nile Delta,...

• War on terrorism

  B) Shock and Bush’s reaction . These attacks are lived as a real trauma by a very big part of the population, which   associates them with Pearl Harbour's attack by Japanese in 1941 who don’t   transmit a preliminary declaration of war. The United States feel at war and the   Bush administration decrees the national mobilization, followed in it by the   American media. In France, Le Monde titles in its publishing dated September   13th, 2001: «We are every Americans ". The shock is transmitted t...

• Public Finance.

  obtained by borrowing instead of taxation—can be helpful for the economy. For example, when unemployment is high, the government can undertake projects that useworkers who would otherwise be idle. The economy will then expand because more money is being pumped into it. However, deficit spending also can harm theeconomy. When unemployment is low, a deficit may result in rising prices, or inflation. The additional government spending creates more competition for scarce workersand resources and thi...

• Shakespeare William, 1564-1616, né à Stratford-on-Avon (Warwickshire), écrivain anglais.

  brûla pendant une représentation de Henry VIII . Shakespeare mourut le 23 avril 1616. En sa qualité de décimateur, il fut enterré dans le chœur de l'église. L'œuvre de Shakespeare. L'œuvre complète fut éditée en 1623 par les soins de deux compagnons de Shakespeare : John Heming et Henry Condell. Le volume, appelé Premier Folio , contient, à l'exception de Périclès , les trente-sept pièces que l'on a maintenant l'habitude d'imprimer dans les éditions de Shakespeare. Dix-huit de ces pièces f...

• Acropolis - geography.

  The Erechtheum is one of the most elaborate buildings on the Acropolis. Its plan is irregular, probably because of the sloping site and the need to preserve earlier placesof worship on the site or nearby. Porches project from three sides of the Erechtheum, but they are at different heights and are not centered on each side. GracefulIonic columns support the porches on the eastern and northern sides. Elegant caryatids (columns carved in the shape of draped female figures) support the Porch of t...

• Acropolis - USA History.

  The Erechtheum is one of the most elaborate buildings on the Acropolis. Its plan is irregular, probably because of the sloping site and the need to preserve earlier placesof worship on the site or nearby. Porches project from three sides of the Erechtheum, but they are at different heights and are not centered on each side. GracefulIonic columns support the porches on the eastern and northern sides. Elegant caryatids (columns carved in the shape of draped female figures) support the Porch of t...

• Qin Dynasty - History.

  measurements. All of these contributed greatly to the Qin's new centralized economy. C Government The Qin government was totalitarian, based on the philosophy of Fajia (Legalism), which placed absolute power in the hands of the ruler, who governed by means of strict laws and harsh punishments. Practical reformers and scholars such as Shang Yang (d. 338 BC) and Han Fei (280?-233 BC) saw Legalism as a way to create a highly efficient, albeit ruthless, administrative apparatus. Qin Shihuangdi...

• 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...

• Heat (physics) I INTRODUCTION Heat Loss from a House A thermograph shows the large amount of heat lost through a house's windows during winter.

  Theoretically, the molecules of a substance would exhibit no activity at the temperature termed absolute zero. See Molecule. III TEMPERATURE SCALES Five different temperature scales are in use today: the Celsius scale, known also as the Centigrade scale, the Fahrenheit scale, the Kelvin scale, the Rankine scale, andthe international thermodynamic temperature scale ( see Thermometer). The Celsius scale, with a freezing point of 0° C and a boiling point of 100° C, is widely used throughout the...

• From Robinson Crusoe - anthology.

  How strange a Chequer-Work of Providence is the Life of Man! and by what secret differing Springs are the Affections hurry'd about as differing Circumstancespresent! To Day we love what to Morrow we hate; to Day we seek what to Morrow we shun; to Day we desire what to Morrow we fear; nay even tremble at theApprehensions of; this was exemplify'd in me at this Time in the most lively Manner imaginable; for I whose only Affliction was, that I seem'd banished from humanSociety, that I was alone, cir...

• Mechanics I INTRODUCTION Mechanics, branch of physics concerning the motions of objects and their response to forces.

  Components of VelocityNeglecting air resistance, a ball thrown into the air at an angle will travel in a parabolic path. The velocity of the ball (V)has independent vertical (V) and horizontal (H) components; the horizontal component stays the same the entire time theball is in the air, while the vertical component, the only component affected by gravity, changes continuously while theball is aloft.© Microsoft Corporation. All Rights Reserved. To understand why and how objects accelerate, force...

• W. L. Mackenzie King. I INTRODUCTION W. L. Mackenzie King (1874-1950), tenth prime

  V SECOND TERM AS PRIME MINISTER By the election of 1925 most of the rifts in the Liberal Party were healed. Little had been achieved by King's government except for some tariff reduction and thereorganization of Canadian railroads, but no mistakes had been made. The real issue of the election was the personalities of the party leaders, King and the brilliant butarrogant Conservative, Arthur Meighen. The Conservatives swept English-speaking Canada, and they won 116 seats. The Liberals won 101, a...

• River.

  IV RIVER PATTERNS River patterns, or general shapes, depend on the geologic zone and the climate of the location. There are four river patterns: meandering, braided, anastomosing, andstraight. A meandering pattern follows a winding, turning course. A braided pattern has connected channels that resemble a hair braid. An anastomosing river patterncombines features of the meandering and braided patterns. Some river patterns are simply straight channels. Meandering and braided are the most common...

• River - Geography.

  IV RIVER PATTERNS River patterns, or general shapes, depend on the geologic zone and the climate of the location. There are four river patterns: meandering, braided, anastomosing, andstraight. A meandering pattern follows a winding, turning course. A braided pattern has connected channels that resemble a hair braid. An anastomosing river patterncombines features of the meandering and braided patterns. Some river patterns are simply straight channels. Meandering and braided are the most common...

• Peter the Great I INTRODUCTION Peter the Great or Peter I (1672-1725), tsar and, later, emperor of Russia (1682-1725), who is linked with the Westernization of Russia and its rise as a great power.

  V LATER REIGN Before long, however, these and other reform measures had to cede center stage to the prosecution of the Great Northern War (1700-1721) against Sweden. Peter’sjourney west did not result in a great alliance against the Ottomans, but it led to one against Sweden. Russia fought together with Denmark and the union of Polandand Saxony against Sweden to win the Baltic coastline, the 'window into Europe,' and to break Swedish dominance over the northern part of the continent. At the tim...