392 résultats pour "facts"

• Albert Einstein.

  On the basis of the general theory of relativity, Einstein accounted for the previously unexplained variations in the orbital motion of the planets and predicted thebending of starlight in the vicinity of a massive body such as the sun. The confirmation of this latter phenomenon during an eclipse of the sun in 1919 became a mediaevent, and Einstein’s fame spread worldwide. For the rest of his life Einstein devoted considerable time to generalizing his theory even more. His last effort, the unifi...

• Charlemagne I INTRODUCTION Charlemagne (742?

  border province). These officials were key to administering the empire. They were kings in miniature, with all of the administrative, judicial, and military authority of theemperor within their respective districts. Each political district had its parallel in a church district, or diocese, headed by a bishop, with similar authority in all mattersrelated to the church. Both counts and bishops were vassals of the emperor, and were overseen by representatives of Charlemagne known as missi dominici...

• Charlemagne.

  border province). These officials were key to administering the empire. They were kings in miniature, with all of the administrative, judicial, and military authority of theemperor within their respective districts. Each political district had its parallel in a church district, or diocese, headed by a bishop, with similar authority in all mattersrelated to the church. Both counts and bishops were vassals of the emperor, and were overseen by representatives of Charlemagne known as missi dominici...

• Charlemagne .

  border province). These officials were key to administering the empire. They were kings in miniature, with all of the administrative, judicial, and military authority of theemperor within their respective districts. Each political district had its parallel in a church district, or diocese, headed by a bishop, with similar authority in all mattersrelated to the church. Both counts and bishops were vassals of the emperor, and were overseen by representatives of Charlemagne known as missi dominici...

• Homer I INTRODUCTION Homer According to tradition, the Greek poet Homer is believed to be the author of the Iliad and the Odyssey, two great epics of ancient Greek literature.

  The Return of OdysseusAfter the Greek warrior Odysseus returns from the Trojan War to his home in Ithaca, he kills the uninvited and unwantedsuitors of his wife, Penelope, who believed him to be dead. Odysseus’s astonishing skill with the bow convinces Penelopethat he is indeed her long-absent husband. This anonymous engraving is of an unknown date.Corbis The Odyssey narrates the return of the Greek hero Odysseus from the Trojan War. The opening scenes depict the disorder that has arisen in Ody...

• Organic Chemistry - chemistry.

  B Alkenes and Alkynes Isomeric with the cyclanes, or cycloalkanes as they are sometimes called, is the family of alkenes, also represented by the general formula C nH2n. This family of hydrocarbons is characterized by one or more double bonds between carbon atoms. Propene and cyclopropane, for example, are isomers, as are 1,3-dimethylcyclohexane and 3,4-dimethyl-2-hexene. (The location of the double bond is indicated by the 2-hexene part of the name.) Double bonds may also occur incyclic compou...

• Hardware (computer).

  Magnetic tape drives use magnetic tape similar to the tape used in VCR cassettes. Tape drives have a very slow read/write time, but have a very high capacity; in fact,their capacity is second only to hard disk drives. Tape drives are mainly used to back up data. Compact disc drives store information on pits burned into the surface of a disc of reflective material ( see CD-ROM). CD-ROMs can store up to 737 megabytes (MB) of data. A Compact Disc-Recordable (CD-R) or Compact Disc-ReWritable (CD-RW)...

• Calvin Coolidge.

  By 1923 President Harding was faced with a number of difficulties. A business depression, which had begun in 1922, continued. In addition, the Republican majorities inboth houses of Congress were reduced in the election of 1922, and a discontented farm bloc of Western Republican senators threatened to destroy the Senate majorityby allying with the Democrats. Finally, it was rumored that major scandals involving Harding's friends were about to break. The rumors were soon proved accurate. The dire...

• Calvin Coolidge

  By 1923 President Harding was faced with a number of difficulties. A business depression, which had begun in 1922, continued. In addition, the Republican majorities inboth houses of Congress were reduced in the election of 1922, and a discontented farm bloc of Western Republican senators threatened to destroy the Senate majorityby allying with the Democrats. Finally, it was rumored that major scandals involving Harding's friends were about to break. The rumors were soon proved accurate. The dire...

• John Macdonald.

  dissolution of the existing Union. The Atlantic colonies, which consisted of Nova Scotia, Prince Edward Island, New Brunswick, and Newfoundland, were considering the question of their own union andplanned to meet at Charlottetown, Prince Edward Island, on September 1, 1864. Macdonald saw his opportunity and secured an invitation for the Canadians to attend.The delegates of the Atlantic colonies put off their own discussion until they had heard the Canadians. Macdonald spoke of the advantages in...

• John Macdonald - Canadian History.

  dissolution of the existing Union. The Atlantic colonies, which consisted of Nova Scotia, Prince Edward Island, New Brunswick, and Newfoundland, were considering the question of their own union andplanned to meet at Charlottetown, Prince Edward Island, on September 1, 1864. Macdonald saw his opportunity and secured an invitation for the Canadians to attend.The delegates of the Atlantic colonies put off their own discussion until they had heard the Canadians. Macdonald spoke of the advantages in...

• John Macdonald - Canadian History.

  dissolution of the existing Union. The Atlantic colonies, which consisted of Nova Scotia, Prince Edward Island, New Brunswick, and Newfoundland, were considering the question of their own union andplanned to meet at Charlottetown, Prince Edward Island, on September 1, 1864. Macdonald saw his opportunity and secured an invitation for the Canadians to attend.The delegates of the Atlantic colonies put off their own discussion until they had heard the Canadians. Macdonald spoke of the advantages in...

• Excerpt from Dombey and Son - anthology.

  light. Rivers and seas were formed to float their ships; rainbows gave them promise of fair weather; winds blew for or against their enterprises; stars and planetscircled in their orbits, to preserve inviolate a system of which they were the centre. Common abbreviations took new meanings in his eyes, and had sole reference tothem. A.D. had no concern with anno Domini, but stood for anno Dombei—and Son. He had risen, as his father had before him, in the course of life and death, from Son to D...

• Nuclear Energy I INTRODUCTION Gundremmingen Nuclear Power Plant, Germany The first of three boiling-water nuclear reactors at Germany's Gundremmingen plant began operating in 1966 but was permanently shut down after being decommissioned in 1983.

  such as ¯U is induced by the absorption of a neutron as in producing cesium-140, rubidium-93, three neutrons, and 200 MeV, or 3.2 × 10 -11 J (7.7 × 10 -12 cal). A nuclear fission reaction releases 10 million times as much energy as is released in a typical chemical reaction. See Nuclear Chemistry. III NUCLEAR ENERGY FROM FISSION The two key characteristics of nuclear fission important for the practical release of nuclear energy are both evident in equation (2). First, the energy per fiss...

• Jimmy Carter.

  B Election of 1976 Carter apparently decided as early as 1972, halfway through his four-year term as governor, that he would seek the presidency of the United States. Soon after the1972 election, his campaign manager drew up a detailed campaign strategy. Carter followed the plan closely, beginning an exhausting schedule of campaigning as soonas his gubernatorial term ended. When Carter formally announced in January 1975 that he was a candidate for president, he had almost no national reputation...

• Jimmy Carter

  B Election of 1976 Carter apparently decided as early as 1972, halfway through his four-year term as governor, that he would seek the presidency of the United States. Soon after the1972 election, his campaign manager drew up a detailed campaign strategy. Carter followed the plan closely, beginning an exhausting schedule of campaigning as soonas his gubernatorial term ended. When Carter formally announced in January 1975 that he was a candidate for president, he had almost no national reputation...

• Sir Robert Borden.

  of the British Empire, Laurier proposed creating a Canadian navy that in case of war could be incorporated into the British navy. The plan was opposed by theConservatives, who thought that Canada should simply provide ships for the British navy. The Québec nationalists also opposed the plan because they did not wantCanada either to participate in the British navy or to have a navy of its own. At the last moment before election day in 1911 it looked as if the Liberals might win. The government ne...

• Sir Robert Borden - Canadian History.

  of the British Empire, Laurier proposed creating a Canadian navy that in case of war could be incorporated into the British navy. The plan was opposed by theConservatives, who thought that Canada should simply provide ships for the British navy. The Québec nationalists also opposed the plan because they did not wantCanada either to participate in the British navy or to have a navy of its own. At the last moment before election day in 1911 it looked as if the Liberals might win. The government ne...

• Hong Kong - geography.

  higher than China’s average standard of living. In 2006 Hong Kong’s per capita gross domestic product (GDP) was $27,679.20, although much of the wealth isconcentrated into relatively few hands. IV ECONOMY Hong Kong’s position as one of the world’s most important economic centers is based on several factors. It is located midway between Japan and Singapore, and it liesastride the main shipping and air routes of the western Pacific. It also has long served as a major port of entry and trade for...

• Reconstruction (U.

  Instead, Congress began a lengthy debate over Reconstruction policy. The program eventually enacted resulted from a series of compromises among Republicanfactions; the Radicals were never powerful enough to gain everything they sought. Still, fueled by anger at the president's refusal to compromise and at the appearanceof former Confederates returning to power throughout the South, members of Congress moved increasingly toward the Radicals. The key Reconstruction measuresenacted aimed to produce...

• 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...

• Sexual Harassment.

  A person who believes he or she has experienced sexual harassment on the job has a limited period of time in which to file a complaint with the EEOC. After the EEOCinvestigates the matter, it issues a right to sue letter, regardless of its conclusions about the matter. The victim then has 90 days to file a lawsuit against the employer in federal court. If he or she is successful in the lawsuit, the victim can receive up to $300,000 in compensatory damages for each incident of unlawful harassme...

• Cloning - biology.

  found that such embryo cells are totipotent (able to give rise to all the different cell types in the body). Exploiting this characteristic, scientists developed three techniques to clone embryo cells: blastomere separation, blastocyst division, and somatic cell nuclear transfer. A Blastomere Separation In blastomere separation, scientists fertilize an egg cell with a sperm cell in a laboratory dish. The resulting embryo is allowed to divide until it forms a mass of aboutfour cells. Scientist...

• Greek Mythology.

  world in search of her; as a result, fertility left the earth. Zeus commanded Hades to release Persephone, but Hades had cunningly given her a pomegranate seed toeat. Having consumed food from the underworld, Persephone was obliged to return below the earth for part of each year. Her return from the underworld each yearmeant the revival of nature and the beginning of spring. This myth was told especially in connection with the Eleusinian Mysteries, sacred rituals observed in the Greektown of Ele...

• Supreme Court of Canada.

  whether the leave to appeal will be granted and the case heard by the Court. The Court has no specified criteria by which it determines whether to grant leave, and the Court does not give reasons for its decision. The key factor appears to be acase’s degree of national importance. Other factors might include the impact of uncertainty in the challenged law, the case’s appropriateness for developing the law torespond to changing social needs, and the presence of a split decision at the court of ap...

• First Americans.

  bones and artifacts helped 19th-century archaeologists establish the age of ancient human encampments in Europe. Yet, search as they might, American archaeologists found no comparable evidence of a Pleistocene-era human presence. But several sites revealed stone artifacts thatsome scholars believed looked similar to the ancient stone tools found in Europe. On the basis of this similarity, these experts claimed the American artifacts must be asold. By the 1890s, however, other scholars had challe...

• First Americans - Canadian History.

  bones and artifacts helped 19th-century archaeologists establish the age of ancient human encampments in Europe. Yet, search as they might, American archaeologists found no comparable evidence of a Pleistocene-era human presence. But several sites revealed stone artifacts thatsome scholars believed looked similar to the ancient stone tools found in Europe. On the basis of this similarity, these experts claimed the American artifacts must be asold. By the 1890s, however, other scholars had challe...

• Philadelphia (city, Pennsylvania) - geography.

  national trend of migration from eastern cities to the warmer climate of the Sun Belt. Whereas in 1950 Philadelphia contained more than 2 million people and ranked as the third largest city in America, the city's population plunged to 1,517,550 by 2000.In 2006, the city's population was estimated at 1,448,394. While the city proper was decreasing in population, the metropolitan area centered on Philadelphia grew. In 2006 the region had 6.2 million inhabitants. Philadelphiaranked as the nation’s...

• 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...

• Environment.

  escape into space of the infrared energy radiated back out by Earth. This process is referred to as the greenhouse effect. These gases, primarily carbon dioxide,methane, nitrous oxide, and water vapor, insulate Earth’s surface, helping to maintain warm temperatures. Without these gases, Earth would be a frozen planet with anaverage temperature of about -18°C (about 0°F) instead of a comfortable 15°C (59°F). If the concentration of these gases rises, they trap more heat within theatmosphere, caus...

• Elementary Particles I INTRODUCTION Structure of Matter Modern physics has revealed successively deeper layers of structure in ordinary matter.

  The most fundamental particles that make up matter fall into the fermion category. These fermions cannot be split into anything smaller. The particles that carry theforces acting on matter and antimatter are bosons called force carriers. Force carriers are also fundamental particles, so they cannot be split into anything smaller.These bosons carry the four basic forces in the universe: the electromagnetic, the gravitational, the strong (force that holds the nuclei of atoms together), and the wea...

• 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...

• Christianity.

  history of architecture. See Basilica; Church; Early Christian Art and Architecture;Prayer. C Christian Life The instruction and exhortation of Christian preaching and teaching concern all the themes of doctrine and morals: the love of God and the love of neighbor, the twochief commandments in the ethical message of Jesus (see Matthew 22: 34-40). Application of these commandments to the concrete situations of human life, bothpersonal and social, does not produce a uniformity of moral or polit...

• Austria - country.

  Wildlife is generally scarce in Austria. Chamois, deer, and marmot are still present; bear, which were once abundant, are now almost completely absent. Hunting isstrictly regulated to protect the remaining species. F Environmental Issues Industrial emissions, a high volume of tourist traffic, and significant air pollution from other countries—principally the former East Germany, Slovakia, and the CzechRepublic—combine to make acid rain the major environmental problem in Austria. One-quarter of...

• French Revolution.

  B2 Assembly of Notables and Estates-General To pressure the parlements into accepting the plan, Calonne decided to gain prior approval of it from an Assembly of Notables—a group of hand-picked dignitaries hethought would sympathize with his views. But Calonne had badly miscalculated. Meeting in January 1787, the assembly refused to believe that a financial crisis reallyexisted. They had been influenced by Necker’s argument that state finances were sound and suspected that the monarchy was only...

• French Revolution .

  B2 Assembly of Notables and Estates-General To pressure the parlements into accepting the plan, Calonne decided to gain prior approval of it from an Assembly of Notables—a group of hand-picked dignitaries hethought would sympathize with his views. But Calonne had badly miscalculated. Meeting in January 1787, the assembly refused to believe that a financial crisis reallyexisted. They had been influenced by Necker’s argument that state finances were sound and suspected that the monarchy was only...

• Heart.

  situation. A Cardiac Cycle Although the right and left halves of the heart are separate, they both contract in unison, producing a single heartbeat. The sequence of events from the beginning ofone heartbeat to the beginning of the next is called the cardiac cycle. The cardiac cycle has two phases: diastole, when the heart’s chambers are relaxed, and systole,when the chambers contract to move blood. During the systolic phase, the atria contract first, followed by contraction of the ventricles. T...

• Fascism.

  values as coming before a radical political transformation. Others argue that a radical political transformation will then be followed by a change in values. Fascists claimthat the nation has entered a dangerous age of mediocrity, weakness, and decline. They are convinced that through their timely action they can save the nation fromitself. Fascists may assert the need to take drastic action against a nation's 'inner' enemies. Fascists promise that with their help the national crisis will end an...

• Renaissance I INTRODUCTION Renaissance, series of literary and cultural movements in the 14th, 15th, and 16th centuries.

  the great writings of ancient Greece and Rome. Intellectuals continued to build on the ideas of the Renaissance during the 18th century Age of Enlightenment, a time when scientific advancements led to a newemphasis on the power of human reason. One of the early Enlightenment thinkers was French philosopher and writer Voltaire. He claimed that the Renaissance was acrucial stage in liberating the mind from the superstition and error that he believed characterized Christian society during the Middl...

• Renaissance .

  the great writings of ancient Greece and Rome. Intellectuals continued to build on the ideas of the Renaissance during the 18th century Age of Enlightenment, a time when scientific advancements led to a newemphasis on the power of human reason. One of the early Enlightenment thinkers was French philosopher and writer Voltaire. He claimed that the Renaissance was acrucial stage in liberating the mind from the superstition and error that he believed characterized Christian society during the Middl...

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• Midnighters