27 résultats pour "revealed"
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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...
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Warren G.
In his few campaign speeches, Harding relied mainly on the political effectiveness of bland generalities. Sometimes his statements were deliberately confusing. Forexample, he promised internationally minded voters that he would support an “association of nations,” while at the same time he promised “America first!” toisolationists. In this way he won the support of influential Republicans who believed in the League of Nations as well as those who opposed it. Harding's inoffensive standon the lea...
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Moon - astronomy.
B Volcanic Features Maria, domes, rilles, and a few craters display indisputable characteristics of volcanic origin. Maria are plains of dark-colored rock that cover approximately 40 percent ofthe Moon's visible hemisphere. The maria formed when molten rock erupted onto the surface and solidified between 3.16 billion and 3.96 billion years ago. This rockresembles terrestrial basalt, a volcanic rock type widely distributed on Earth, but the rock that formed the maria has a higher iron content an...
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Surrealism
I
INTRODUCTION
Surrealism, artistic and literary movement that explored and celebrated the realm of dreams and the unconscious mind through the creation of visual art, poetry, and
motion pictures.
Hieronymus Bosch’s The Garden of Earthly Delights (about 1505-1510).© 2008 Salvador Dali, Gala-Salvador Dali Foundation / Artists Rights Society (ARS), New York./Bridgeman Art Library, London/New York Dreams, according to Freud, were the royal road to studying the unconscious, because it is in dreams that our unconscious, primal desires manifest themselves. Theincongruities in dreams, Freud believed, result from a struggle for dominance of ego and id. In attempting to access the real workings of...
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Venus (planet) - astronomy.
level winds circle the planet at 360 km/h (225 mph), making a complete rotation in only four days. These winds are said to super-rotate because they travel muchfaster than the rotation of the planet itself. These high-speed winds cover the planet completely, blowing toward the west at virtually every latitude from equator topole. The motions of descending probes, however, have shown that the bulk of Venus’s tremendously dense atmosphere, closer to the planet’s surface, is almoststagnant. From th...
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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...
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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...
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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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Mars (planet) - astronomy.
The Martian core is probably much like Earth’s, consisting mostly of iron, with a small amount of nickel. If other light elements, particularly sulfur, exist there as well, thecore may be larger than presently thought. From studying Earth’s magnetic field and core, scientists theorize that the motions of the liquid rock in Earth’s core generateits magnetic field. Mars does not have a significant magnetic field, so scientists believe that Mars’s core is probably solid. However, spacecraft data in...
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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...
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Mercury (planet) - astronomy.
In 1991 powerful radio telescopes on Earth revealed signs of possible deposits of ice in the polar regions of Mercury. These ice deposits occur in areas where sunlightnever falls, such as crater bottoms near both of the planet’s poles. Similar ice deposits may have been found during the 1990s near the poles of the Moon by theClementine and Lunar Prospector spacecrafts. The ice on Mercury likely comes from comets or water-bearing meteorites that have hit Mercury over the planet’s historyup throug...
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Classification - biology.
species based on the fewest number of shared changes that have occurred from generation to generation. IV HISTORY OF CLASSIFICATION SYSTEMS Classification is one of the oldest sciences, but despite its age it is still a vigorous field full of new discoveries and methods. Much like other fields of science, greatthinkers have shaped the course of classification. One of the earliest classification schemes was established by Greek philosopher Aristotle, who lived in the 300s BC. Aristotle believe...
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Inorganic Chemistry - chemistry.
two electrically charged plates (positively charged top plate and negatively charged bottom plate). By measuring the difference in how fast these electron-laden oildrops fell when the metal plates were charged and uncharged, Millikan was able to calculate the total charge on each oil drop. Because each measurement was a wholenumber multiple of -1.60 × 10 -19 coulombs, Millikan concluded this was the charge carried by a single electron. Using Thomson’s electron charge-to-mass ratio, Millikan then...
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Evolution - biology.
genetic diversity to extinction. Sexual reproduction ensures that the genes in a population are rearranged in each generation, a process termed recombination. Although the combinations of genes inindividuals change with each new generation, the gene frequency, or ratio of different alleles in the entire population, remains relatively constant if no evolutionaryforces act on the population. One such force is the introduction of new genes into the genetic material of the population, or gene pool...
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Poker.
After the ante and the initial deal, the first round of betting starts with the player to the left of the dealer. This bettor can check (make no bet), make a bet, or fold. To stay in the game, subsequent bettors must call (match the current bet) or raise (increase the total bet). A round of betting ends when no player makes a further bet or a set limit of turns around the table has been reached. In the next round of betting, the player to the left of the bettor that started the last round o...
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Jesus Christ
I
INTRODUCTION
Jesus Christ (between 8 and 4
BC-AD
29?
Monday and Tuesday, according to the synoptists), he drove from the Temple the traders and moneychangers who, by long-established custom, had been allowed totransact business in the outer court (Mark 11:15-19), and he disputed with the chief priests, the scribes, the Pharisees, and the Sadducees questions about hisauthority, tribute to Caesar, and the resurrection. On Tuesday, Jesus also revealed to his disciples the signs that would usher in his Parousia, or second coming. See Second Coming. O...
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Jesus Christ.
Monday and Tuesday, according to the synoptists), he drove from the Temple the traders and moneychangers who, by long-established custom, had been allowed totransact business in the outer court (Mark 11:15-19), and he disputed with the chief priests, the scribes, the Pharisees, and the Sadducees questions about hisauthority, tribute to Caesar, and the resurrection. On Tuesday, Jesus also revealed to his disciples the signs that would usher in his Parousia, or second coming. See Second Coming. O...
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Qur'an.
man who profoundly influenced the history of the world. See Spread of Islam. Muhammad’s home, the Arab city of Mecca, was a major religious center and site of the revered sanctuary and shrine, the Kaaba. According to legend, the ancientreligious patriarch of the Hebrew Bible, Abraham, and his son, Ishmael, built the shrine using foundations laid by the first human being and father of humankind, Adam.During Muhammad’s years there, from about AD 570 to 622, Mecca was also an environment of spir...
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From The Scarlet Letter - anthology.
“Mercy on us, goodwife,” exclaimed a man in the crowd, “is there no virtue in woman, save what springs from a wholesome fear of the gallows? That is the hardestword yet! Hush, now, gossips; for the lock is turning in the prison-door, and here comes Mistress Prynne herself.” The door of the jail being flung open from within, there appeared, in the first place, like a black shadow emerging into the sunshine, the grim and grisly presence ofthe town-beadle, with a sword by his side and his staff...
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Saturn - astronomy.
measurements of the magnetic field made by the Voyager space probes in the 1980s. Additional Cassini findings reported in March 2007 suggested that particles originating from geysers on the moon Enceladus may provide a partial explanation for thechange. The neutral gas particles become electrically charged and are captured by Saturn’s magnetic field, forming a disk of hot, ionized gas around the planet’sequator. The charged particles interact with the magnetic field and slow down the rotation of...
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Gerald Ford.
In May 1973 the Senate Select Committee on Presidential Activities opened hearings and in a series of startling revelations, Dean testified that Mitchell had ordered thebreak-in and that the president had authorized payments to the burglars to keep them quiet. The Nixon administration vehemently denied these assertions. In March 1974 a grand jury indicted Mitchell, Haldeman, Ehrlichman, and four other White House officials for their part in covering up the Watergate break-in andreferred to Nixon...
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Gerald Ford
In May 1973 the Senate Select Committee on Presidential Activities opened hearings and in a series of startling revelations, Dean testified that Mitchell had ordered thebreak-in and that the president had authorized payments to the burglars to keep them quiet. The Nixon administration vehemently denied these assertions. In March 1974 a grand jury indicted Mitchell, Haldeman, Ehrlichman, and four other White House officials for their part in covering up the Watergate break-in andreferred to Nixon...
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Asteroid - astronomy.
Asteroids of the S type, related to the stony iron meteorites, make up about 15 percent of the total population of asteroids that can be seen from Earth. Much rarer arethe M-type objects, corresponding in composition to the meteorites known as “irons.” These objects are made up of an iron-nickel alloy and may represent the cores ofbodies that were large enough to differentiate into layers and to melt deep inside. Their rocky outer layers may have been removed by impacts with other asteroids . A...
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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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Mental Illness.
note that under this definition, political dissidents could be considered mentally ill for refusing to accept the dictates of their government. VI PREVALENCE Mental illness affects people of all ages, races, cultures, and socioeconomic classes. The prevalence of mental illness refers to how many people experience a mentalillness during a specified time period. A United States and Worldwide In the United States, researchers estimate that about 24 percent of people 18 or older, or about 44 mill...
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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...
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Terrorism.
exploitation, ethnic discrimination, and religious persecution. Perceived inequities in the distribution of wealth and political power have led some terrorists to attempt tooverthrow democratically elected governments. To achieve a fairer society, they would replace these governments with socialist or communist regimes. Left-wingterrorist groups of the 1960s and 1970s with such aims included Germany’s Baader-Meinhof Gang, Italy’s Red Brigades, and the Weather Underground ( see Weathermen) in the...