627 résultats pour "before"

• Optics I INTRODUCTION Mirage Mirages appear because differences in air temperature cause light rays from an object to take different paths to a viewer's eye.

  Refraction of Light by DiamondsThe brilliance of diamonds is due to their high refractive index, a measure of how strongly a transparent material bendslight rays. The skill of the gem-cutter lies in angling the facets of the stone so that each light ray entering it is reflectedmany times before it emerges again.Spencer Grant/Photo Researchers, Inc. The amount of light reflected depends on the ratio of the refractive indexes for the two media. The plane of incidence contains the incident ray and...

• New Orleans - geography.

  D Metropolitan Region The New Orleans metropolitan region covers 8,800 sq km (3,400 sq mi) and includes the counties—known in Louisiana as parishes— of Orleans, Jefferson, Saint Bernard, Saint Charles, Saint John the Baptist, Saint Tammany, Saint James, and Plaquemines. At the center is the city of New Orleans, which is coextensive withOrleans Parish. It has a land area of 468 sq km (181 sq mi). Extending from this base are numerous suburban towns in the surrounding parishes. Metairie, Harahan...

• Physics I INTRODUCTION Physics, major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces.

  Starting about 1665, at the age of 23, Newton enunciated the principles of mechanics, formulated the law of universal gravitation, separated white light into colors,proposed a theory for the propagation of light, and invented differential and integral calculus. Newton's contributions covered an enormous range of naturalphenomena: He was thus able to show that not only Kepler's laws of planetary motion but also Galileo's discoveries of falling bodies follow a combination of his ownsecond law of m...

• Holy Roman Empire I INTRODUCTION Holy Roman Empire, political entity of lands in western and central Europe, founded by Charlemagne in AD 800 and dissolved by Emperor Francis II in 1806.

  acquired the imperial title and an area running from the North Sea through Lotharingia (Lorraine) and Burgundy to northern Italy; Louis II received East Francia (theGerman duchies of Saxony, Swabia, and Bavaria). In 870 Lothair’s middle kingdom was divided by the Treaty of Mersen, which gave Lotharingia to East Francia and therest to West Francia. This division created the foundation for today’s states of Germany and France, respectively; however, in the 9th century these were highly fractured d...

• Holy Roman Empire .

  acquired the imperial title and an area running from the North Sea through Lotharingia (Lorraine) and Burgundy to northern Italy; Louis II received East Francia (theGerman duchies of Saxony, Swabia, and Bavaria). In 870 Lothair’s middle kingdom was divided by the Treaty of Mersen, which gave Lotharingia to East Francia and therest to West Francia. This division created the foundation for today’s states of Germany and France, respectively; however, in the 9th century these were highly fractured d...

• Berlin - geography.

  boroughs of Wedding and Tiergarten. Other important central areas include Kreuzberg and Friedrichshain, now united as the Friedrichshain-Kreuzberg borough, andPrenzlauer Berg, now incorporated as a part of the Pankow borough. Tiergarten contains a large wooded park, a zoo, and a variety of public monuments as well as the large, modern Congress Hall and the Reichstag building, which wasbuilt from 1884 to 1894. The Reichstag and the surrounding area have undergone renovation to accommodate the Bun...

• Ant - biology.

  The workers of many ant species carry a stinger within the hind end of the gaster. These ants use the stinger to defend against their enemies. In some species, workerants lack a stinger but use the tip of their gaster to squirt or dab poison at other small animals and when fighting battles with other ants, fending off predators, or killinginsects or other animals that they use as food. III PHYSIOLOGY Ants have a rigid, external skeleton called an exoskeleton that gives the soft, inner body its...

• 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...

• Labor Union.

  B The Legal Environment The legal environment, which permits certain types of union activities and prohibits others, also influences the extent of union organization. States with right-to-worklaws have much lower unionization rates than other states. In the United States, the states with the lowest unionization rates are North Carolina, South Carolina, SouthDakota, and Arkansas—states that have right-to-work laws. In 2000 the unionization rate in these states ranged from 4.44 percent to 6.7 per...

• Western Music I INTRODUCTION Bizet's Carmen Georges Bizet's Carmen, first performed in Paris in 1875, was a milestone in the history of French opera.

  church ceremonies during the period from the 5th to the 7th century. Roman chant became known as Gregorian chant after Pope Gregory I, the Great, who may havecomposed some of the melodies and who actively encouraged an orderly, ritualized use of music by the church. Because Gregory and later popes preferred Gregorianchant to the varieties that had developed elsewhere in Europe, Gregorian chant eventually superseded most of the others. Gregorian and other chant styles arepreserved in many manuscr...

• Electricity I INTRODUCTION Electricity, one of the basic forms of energy.

  electrons in the neutral object are attracted to the positive object. Some of these electrons flow to the side of the neutral object that is nearest to the positive object.This side of the neutral object accumulates electrons and becomes negatively charged. Because electrons leave the far side of the neutral object while its protonsremain stationary, that side becomes positively charged. Since the negatively charged side of the neutral object is closest to the positive object, the attraction bet...

• Stone Age.

  limestone, quartzite, and indurated shale. Ground stone tools could be made on a wider range of raw material types, including coarser grained rock such as granite. Flaking produces several different types of stone artifacts, which archaeologists look for at prehistoric sites. The parent pieces of rock from which chips have beendetached are called cores, and the chips that have been removed from cores are called flakes. A flake that has had yet smaller flakes removed from one or more edgesin orde...

• History of Colonial America - U.

  Despite the lack of settlement, New France prospered as a vast fur-trading enterprise. French explorers traveled deep into the North American continent seeking newsupplies of deerskins and beaver pelts. In 1673 French missionary Jacques Marquette reached the Mississippi River in present-day Wisconsin. In 1681 explorer René-Robert Cavelier, Sieur de La Salle, traveled down the majestic Mississippi to the Gulf of Mexico. He honored the reign of King Louis XIV (1643-1715) by creating the newcolony...

• Theater I INTRODUCTION The Art of Theater BBC Worldwide Americas, Inc.

  Theater at EpidaurusAncient Greek dramas were performed in open-air theaters like this one in Epidaurus, Greece, which was designed byPolyclitus the Younger in 350 bc. A festival of ancient Greek drama is still held in the summer in this 14,000-seat theater.Roger Wood/Corbis Fundamental to the theater experience is the act of seeing and being seen; in fact, the word theater comes from the Greek word theatron , meaning 'seeing place.' Throughout the history of world cultures, actors have used...

• Colorado - geography.

  Although the rivers of Colorado are navigable only by small boats, they are important as a source of irrigation water for use in Colorado and adjoining states. However,the water level of the rivers fluctuates seasonally and from year to year. The level is generally low in winter and high in spring and summer, during the runoff of meltedsnow from the mountains. Colorado has no large lakes of natural origin, but there are numerous small lakes in the mountains. The largest bodies of water in Colora...

• Colorado - USA History.

  Although the rivers of Colorado are navigable only by small boats, they are important as a source of irrigation water for use in Colorado and adjoining states. However,the water level of the rivers fluctuates seasonally and from year to year. The level is generally low in winter and high in spring and summer, during the runoff of meltedsnow from the mountains. Colorado has no large lakes of natural origin, but there are numerous small lakes in the mountains. The largest bodies of water in Colora...

• New York (city) - geography.

  The Bronx is the fourth largest and the northernmost of the five boroughs, and the only one on the American mainland. Even so, it is surrounded by water on threesides: Long Island Sound on the east, the Harlem and East rivers on the south, and Hudson River on the west. Encompassing 109 sq km (42 sq mi), it had 1,332,650inhabitants in 2000. Largely residential, the Bronx includes dozens of vibrant neighborhoods. Fieldston is particularly elegant, with great stone houses set among spacious lawns a...

• Virginia (state) - geography.

  C Coastline Virginia’s coastline, for both the mainland and the Eastern Shore counties, is 180 km (112 mi) long. The state’s tidal shoreline measures 5,335 km (3,315 mi), includingall bays, inlets, tidal estuaries, and other indentations. Major indentations include Chesapeake Bay; Hampton Roads, the excellent natural harbor on which are locatedNewport News, Norfolk, and Portsmouth; and the wide tidal estuaries of the lower Potomac, James, Rappahannock, and York rivers. Cape Henry, in the southe...

• Virginia (state) - USA History.

  C Coastline Virginia’s coastline, for both the mainland and the Eastern Shore counties, is 180 km (112 mi) long. The state’s tidal shoreline measures 5,335 km (3,315 mi), includingall bays, inlets, tidal estuaries, and other indentations. Major indentations include Chesapeake Bay; Hampton Roads, the excellent natural harbor on which are locatedNewport News, Norfolk, and Portsmouth; and the wide tidal estuaries of the lower Potomac, James, Rappahannock, and York rivers. Cape Henry, in the southe...

• avion

  Blitzkrieg and the Battle of Britain is the first air battle in history. The war unfortunately also mark the beginning of the bombing of civilian targets carried out with training hundreds of planes: first by Germany (raids on Rotterdam and Coventry in 1940) and Japan, followed by the United States and the United Kingdom from 1943 (raids on Hamburg, Tokyo, etc.).. Asia, World War II ends after the atomic bombings of Hiroshima and Nagasaki. 2/Description and the way it works Aircraft...

• Burley, Walter

  not lost, as in the succession theory, but becomes part of the new degree. However, as long as the issue of how to explain the intension and remission of forms continued to be discussed, the succession theory was nearly always taken seriously. Burley's treatise on first and last instants represents a standard view. For Burley, as for most other fourteenth-century authors, 'permanent' entities - that is, those that are wholly existent at once, unlike motion - have a first instant of being bu...

• William Faulkner.

  published shortly before his death the same year. Selected Letters of William Faulkner , edited by Joseph Blotner, was issued in 1977. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

• Poetry of Lord Byron - anthology.

  A mind at peace with all below,A heart whose love is innocent! “Stanzas for Music” There be none of Beauty's daughtersWith a magic like thee;And like music on the watersIs thy sweet voice to me:When, as if its sound were causingThe charmed Ocean's pausing,The waves lie still and gleaming,And the lulled winds seem dreaming: And the midnight Moon is weavingHer bright chain o'er the deep;Whose breast is gently heaving,As an infant's asleep:So the spirit bows before thee,To listen and adore thee;Wit...

• L'HISTOIRE - POURQUOI ELLE NOUS CONCERNE ?

• Essay racism

  peoples are used and the creation of communities. Racism is also a problem in employment. Most of the time, the white people are always hired first. The most well-known example is the presidential in the U.S. nobody who has a skin color became president of the United States before B. Obama in 2009. However, it shows that the Americans are less racist but it means that it took time for them to finally trust and see that we are all equal no matter what. To conclude, racism is not an ability that p...

• From Bulfinch's Mythology: Beowulf - anthology.

  help his aged monarch. Another rush of the dragon shattered Beowulf's sword and the monster's fangs sunk into Beowulf's neck. Wiglaf, rushing into the struggle,helped the dying Beowulf to kill the dragon. Before his death, Beowulf named Wiglaf his successor to the throne of Geatland and ordered that his own ashes be placed in a memorial shrine at the top of a highcliff commanding the sea. Beowulf's body was burned on a vast funeral pyre, while twelve Geats rode around the mound singing their...

• Anselm of Canterbury

  twenty-six years old. After his father's death (presumably in 1060), Anselm chose to enter the monastic order atBec rather than return to the family estate. In 1063 he was elected prior of Bec, succeeding Lanfranc, who hadbeen called to the abbey of St.-Etienne in Caen; in 1078 he was chosen abbot, in spite of his disinclination toassume the office. He showed even more reluctance and protestation when selected as archbishop of Canterbury in1093, again in succession to Lanfranc. Eadmer tells...

• Demeter - Mythology.

  disguised herself as an old woman, wearing a hood. The king’s wife, Metaneira, welcomed Demeter and asked her to look after her newborn son, Demophon. Demeter nourished the infant on ambrosia (food of the gods) and each night placed him in the fire in order to destroy all that was mortal in him, so that he would grow up like a god. One night, Metaneira spied upon her nurse and saw her place the child in the fire. Metaneira screamed with terror. Demeter was angry at the intrusion. Demete...

• Excerpt from A Christmas Carol - anthology.

  External heat and cold had little influence on Scrooge. No warmth could warm, no wintry weather chill him. No wind that blew was bitterer than he, no falling snowwas more intent upon its purpose, no pelting rain less open to entreaty. Foul weather didn’t know where to have him. The heaviest rain, and snow, and hail, and sleet,could boast of the advantage over him in only one respect. They often “came down” handsomely and Scrooge never did. Nobody ever stopped him in the street to say, with g...

• Lifehack

• Gehrig Bids Farewell.

  “We want Lou! We want Lou!” the crowd chanted. The emcee looked over to Gehrig. Gehrig slowly shook his head from side to side. Workers began removing thesound equipment. Gehrig headed for the dugout but then turned around. McCarthy said something to him, which the New York Times lip-read as, “Come on, Lou, just rap out another.” Gehrig held up his hand to get the crowd's attention, swallowed hard, and forced a smile. Fiddling with his cap and scratching at the turf with his cleats, he spo...

• Excerpt from King Lear - anthology.

  Find out their enemies now. Tremble, thou wretchThat hast within thee undivulgéd crimesUnwhipped of justice. Hide thee, thou bloody hand,Thou perjured, and thou simular of virtueThat art incestuous. Caitiff, to pieces shake,That under covert and convenient seemingHas practised on man’s life. Close pent-up guilts,Rive your concealing continents, and cryThese dreadful summoners grace. I am a manMore sinned against than sinning. KENT. Alack, bare-headed?Gracious my lord, hard by here is a hovel;Som...

• Reproduction - biology.

  E Gestation After fertilization of the egg, the resulting zygote undergoes cell division and differentiation to form the embryo. In most higher plants, the embryo is enclosed in a layerof nutritive material surrounded by a hard outer covering, forming the seed. In most lower animals the embryo, surrounded by the nutritive material of the formerovum, is enveloped by a leathery or calcareous shell and is extruded from the body of the female. Animals, such as birds, that lay their eggs before the...

• Blankers-Koen Wins Fourth Gold Medal.

  Blankers-Koen's final event was the 4 x 100-meter relay. Her decision to enter the race revealed much about her character. Under Olympic rules, she could enter amaximum of four events. Even though she owned the world records for the long jump and high jump, she instead opted for the relay. She explained that a “team”victory would hold more meaning to her country and its citizens. Blankers-Koen's superb anchor leg clinched Holland's victory. Meanwhile, in the long jump,Hungary's Olga Gyarmati won...

• From Pride and Prejudice - anthology.

  But why Mr Darcy same so often to the Parsonage, it was more difficult to understand. It could not be for society, as he frequently sat there ten minutes togetherwithout opening his lips; and when he did speak, it seemed the effect of necessity rather than of choice—a sacrifice to propriety, not a pleasure to himself. He seldomappeared really animated. Mrs Collins knew not what to make of him. Colonel Fitzwilliam's occasionally laughing at his stupidity, proved that he was generallydifferent, wh...

• Dwight Clark's Catch.

  On third down and three, with 51 seconds left, and in need of a touchdown, San Francisco called time-out. Montana and Walsh discussed the play, which wasdesigned to go to Solomon. But as Montana rolled to his right, he spotted Clark behind the defense. With Cowboys defensive linemen D. D. Lewis, Larry Bethea, andJones closing, Montana threw a hurried jump pass that Clark reached up and gathered in. A final point by Ray Wersching gave the 49ers the victory, 28-27. “I hear all the time, especi...

• THE ALCHIMIST

  Pau lo C oelh o - T he A lc h em is t 2 o f 6 8 w ho l iv ed i n t h e v illa g e t h ey w ould r e ach i n a b out f o ur d ay s. H e h ad b een t o t h e v illa g e o nly o n ce, t h e y ear b efo re . T he m erc h an t w as t h e p ro prie to r o f a d ry g oods s h op, a n d h e a lw ay s d em an ded t h at t h e s h eep b e s h eare d i n h is p re se n ce, s o t h at h e w ould n ot b e c h eate d . A f r ie n d h ad t o ld t h e b oy a b out t h e s h op, a n d...

• Oerter Wins Third Gold Medal.

  Few expected Oerter to show up for the qualifying rounds. Nevertheless he did, with several parts of his 6-foot-4-inch, 270-pound body wrapped in tape, packed inice, and numbed with Novocain. After doffing his neck brace, he propelled the discus a miraculous 198 ft 7.5 in (60.5 m) in his first effort, achieving anotherOlympic record. Wrenched with pain, Oerter told a teammate before the start of the final round that his only chance to win was with a strong first throw. His initial effort, ho...

• Coffee - biology.

  States law, the addition of chicory or any other substance must be clearly stated on the brand label. IV HISTORY Exactly where and when coffee was first cultivated is not known, but some authorities believe that it was grown initially in Arabia near the Red Sea about AD675. Coffee cultivation was rare until the 15th and 16th centuries, when extensive planting of the tree occurred in the Yemen region of Arabia. The consumption of coffee increasedin Europe during the 17th century, prompting the...

• Midnighters

• Excerpt from The Two Gentlemen of Verona - anthology.

  JULIA. Is he among these? HOST. Ay; but, peace! Let’s hear 'em. SONG:Who is Silvia? What is she,That all our swains commend her?Holy, fair, and wise is she;The heaven such grace did lend her,That she might admirèd be. Is she kind as she is fair?For beauty lives with kindness.Love doth to her eyes repair,To help him of his blindness;And, being helped, inhabits there. Then to Silvia let us singThat Silvia is excelling;She excels each mortal thingUpon the dull earth dwelling.To her let us garlands...

• Charlottetown - Geography.

  Royalty. In 1864 Charlottetown was the site of the Charlottetown Conference, a meeting between representatives of most of the British North American colonies to discussConfederation. The meeting was a success, and led eventually to the establishment of the Dominion of Canada in 1867. Charlottetown was incorporated in 1855, with a population of 6500. On July 16, 1866, the city experienced its worst of several fires. “The Great Fire” broke out in an oldbuilding near the waterfront. It was thought...

• Roma Roman A legendary figure who came to be worshiped as a goddess, Roma was the personification of the city of Rome.

  became Rome. The first hill people settled appears to have been the Capitoline Hill. Archaeologists have discovered some of the oldest temples to the supreme Roman god, Jupiter, on this hill. According to legend, it was on this hill that Romulus founded his city. The next hill that settlers developed was the nearby Palatine, 1,250 yards to the southeast of the Capitoline Hill. Legend says that Evander, a leader from the Arcadia region of ancient Greece, settled this hill even before Romulus was...

• If he asks anything, just let him know that it will be OK.

  That's true. It's ashame tobe inside. I guess so. But here weare. I wanted toturn toface him, butIcouldn't. Imoved myhand totouch hishand. They letyou outofschool? Practically immediately. Do you know whathappened? Yeah. Have youheard fromMom orDad? Mom. What didshe say? She said everything wasfineandshewould behome soon. Dad willbehome soon,too.Once hecan close upthe store. Yeah. You pressed yourpalms intothebed likeyou were trying tolift itoff us. Iwanted totell you something, butIdidn't know...

• aircraft, Japanese

• Congo (river) - Geography.

  region as Portuguese territory, leaving a marble shaft on the riverbank as proof of his discovery. To Europeans the river became known as the Rio de Padrão (Pillar River). The Kongo king welcomed Cam and subsequent Portuguese explorers and established friendly trading relations with the Portuguese. More than 300 yearselapsed before serious exploration of the Congo was undertaken. Francisco José de Lacerda, a Portuguese explorer, reached the copper-rich Katanga region from the east in 1798, as...

• From Bulfinch's Mythology: Ibycus - anthology.

  The choristers, clad in black, bore in their fleshless hands torches blazing with a pitchy flame. Their cheeks were bloodless, and in place of hair writhing and swellingserpents curled around their brows. Forming a circle, these awful beings sang their hymns, rending the hearts of the guilty, and enchaining all their faculties. It roseand swelled, overpowering the sound of the instruments, stealing the judgment, palsying the heart, curdling the blood. 'Happy the man who keeps his heart pure...

• Hayes Wins Olympic Marathon.

  entered the stadium,” Pietri told the New York Times after the race. “When I heard the people cheering and knew I had nearly won, a thrill passed through me and I felt my strength going.” Visibly confused, Pietri stood for a moment before making a wrong turn—heading left instead of following a red cord to the right. Officials tried to redirect thedelirious runner, but only after several attempts did he correctly change his course. “He staggered along the cinder path like a man in a dre...

• Edmonton - Geography.

  both of which built fur trading posts near present-day Edmonton in 1795. The posts were rebuilt several times, always along the North Saskatchewan River, whichprovided the traders’ main transportation route. The last move came in 1830, when Fort Edmonton was erected on the high bluff where the Alberta Legislature nowstands. For the next 50 years, the fort was the major trading center on the western plains. The modern city began to take shape after 1900, when central Alberta was opened to Europea...

• Churchill: "The Sinews of Peace" On March 5, 1946, in a

  safeguards to make it effective, these powers would naturally be confided to that world organisation. Now I come to the second danger of these two marauders which threatens the cottage, the home, and the ordinary people—namely, tyranny. We cannot be blind tothe fact that the liberties enjoyed by individual citizens throughout the British Empire are not valid in a considerable number of countries, some of which are verypowerful. In these States control is enforced upon the common people by variou...