371 résultats pour "near"

• NEAR-Shoemaker - astronomie.

• Claude Monet I INTRODUCTION Monet's Gardens at Giverny From 1890 until his death in 1926, Claude Monet lived and painted in the small village of Giverny, near Paris.

  small works, Monet’s quick daubs of fresh colors aptly capture the movement of the water and gaiety of the scene. Despite his father's disapproval, in 1870 Monet married Camille, who had already borne him a son. To escape the Franco-Prussian War (1870-1871), during whichGerman troops threatened Paris, the couple went to London, then to Holland. They returned in 1872 and settled in Argenteuil, a sailing center on the Seine Riveroutside Paris. Monet painted numerous vibrant, light-filled views of...

• Vincent van Gogh I INTRODUCTION Church at Auvers by Van Gogh Dutch artist Vincent van Gogh spent the last months of his life in Auvers-sur-Oise, near Paris, under the care of Dr.

  III PARIS Van Gogh's Self-PortraitThe burning eyes of this Self-Portrait are an example of how 19th-century Dutch painter Vincent van Gogh attempted tocapture the human essence and emotions of his subjects. During the last several years of his life, van Gogh created anumber of self-portraits. The expressive brushstrokes and vibrant colors in these paintings are typical of this later style.Bridgeman/Art Resource, NY In 1886 van Gogh went to live with Théo in Paris, where he became familiar with...

• 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...

• Florida - USA History.

  accidentally introduced into the region in the 1880s, and it spread with alarming rapidity throughout the upper reaches of the river. The plant is very difficult toeradicate, and it has also clogged the channels of other Florida rivers. To increase drainage of the Everglades, which drain naturally to Florida Bay and the Gulf ofMexico, a number of drainage channels and canals have been built across southern Florida. Among the rivers flowing from the peninsula to the Gulf of Mexico are the Suwanne...

• 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...

• Radio Astronomy - astronomy.

  equivalent to the apparent angular dimensions of a basketball at the distance of the moon. In 1984, the U.S. government appropriated funds for the construction of aninstallation called the very long baseline array (VLBA), a network of 10 radio antennas spread from the U.S.-Canadian border to Puerto Rico and from Hawaii to the U.S.Atlantic coast. The VLBA is expected to provide angular resolutions in the range of 200-millionths of an arc second. Canada and Australia are both planning similarprogr...

• Oregon - geography.

  B Rivers and Lakes The Columbia River forms most of the Oregon-Washington boundary, and with its tributaries this great river drains a large portion of Oregon. From the point where theColumbia first touches the state, at Wallula Gap, the river runs in a shallow gorge, deepening as it approaches the Cascades. This part of the river once had manyrapids and falls, but is now navigable by large vessels because of dams and locks that have been built along much of its length. An important tributary o...

• Oregon - USA History.

  B Rivers and Lakes The Columbia River forms most of the Oregon-Washington boundary, and with its tributaries this great river drains a large portion of Oregon. From the point where theColumbia first touches the state, at Wallula Gap, the river runs in a shallow gorge, deepening as it approaches the Cascades. This part of the river once had manyrapids and falls, but is now navigable by large vessels because of dams and locks that have been built along much of its length. An important tributary o...

• Québec - Geography.

  facilities. Tributaries south of the St. Lawrence include the Richelieu, the Saint-François, and the Chaudière rivers, which are only a few hundred kilometers long. TheRimouski and Matane rivers, also south of the St. Lawrence, are popular areas for recreation and salmon fishing. In the Canadian Shield, the longest rivers are theRupert, Eastmain, Grande Baleine, and La Grand-Rivière, which is the site of a huge hydroelectric complex. C Coastlines Québec has two systems of saltwater coastline. O...

• Québec - Canadian History.

  facilities. Tributaries south of the St. Lawrence include the Richelieu, the Saint-François, and the Chaudière rivers, which are only a few hundred kilometers long. TheRimouski and Matane rivers, also south of the St. Lawrence, are popular areas for recreation and salmon fishing. In the Canadian Shield, the longest rivers are theRupert, Eastmain, Grande Baleine, and La Grand-Rivière, which is the site of a huge hydroelectric complex. C Coastlines Québec has two systems of saltwater coastline. O...

• Pyramids (Egypt) - geography.

  limestone debris left over from the construction work. When the workers had completed the pyramid and installed the pyramidion, or cap stone, ramps still covered the surface of the pyramid. As the workers dismantled the ramps from the top down, they slowly exposed the pyramid’s stone surface, which stonemasons smoothed and polished. When the ramp was gone, the pyramid wasdisplayed in its full majesty. B Interior The interior of the Great Pyramid is complex, with a series of passages leading t...

• Pyramids (Egypt) - History.

  limestone debris left over from the construction work. When the workers had completed the pyramid and installed the pyramidion, or cap stone, ramps still covered the surface of the pyramid. As the workers dismantled the ramps from the top down, they slowly exposed the pyramid’s stone surface, which stonemasons smoothed and polished. When the ramp was gone, the pyramid wasdisplayed in its full majesty. B Interior The interior of the Great Pyramid is complex, with a series of passages leading t...

• Missouri - geography.

  Saint Francois Mountains, at the eastern end of the crest of the dome. Only in these mountains have the sedimentary rocks been sufficiently eroded away so that theunderlying igneous rocks are exposed. They form the rounded, knoblike peaks of an old mountain range. The peaks project, in isolation or in clusters, between 230 and300 m (750 and 1,000 ft) above the surrounding sedimentary basins. One of these knobs, Taum Sauk Mountain, reaches 540 m (1,772 ft) above sea level and is thehighest point...

• Missouri - USA History.

  Saint Francois Mountains, at the eastern end of the crest of the dome. Only in these mountains have the sedimentary rocks been sufficiently eroded away so that theunderlying igneous rocks are exposed. They form the rounded, knoblike peaks of an old mountain range. The peaks project, in isolation or in clusters, between 230 and300 m (750 and 1,000 ft) above the surrounding sedimentary basins. One of these knobs, Taum Sauk Mountain, reaches 540 m (1,772 ft) above sea level and is thehighest point...

• 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...

• Iran - country.

  Zagros mountains. In the more arid central part of the country, wild pistachio and other drought-resistant trees grow in areas that have not been disturbed by humanactivity. Tamarisk and other salt-tolerant bushes grow along the margins of the Dasht-e Kavir. A wide variety of native mammals, reptiles, birds, and insects inhabit Iran. Many species of mammals—including wolves, foxes, bears, mountain goats, red mountainsheep, rabbits, and gerbils—continue to thrive. Others—including Caspian tigers,...

• Weather.

  hours, and the snow can be much deeper in places where the wind piles it up in drifts. Extraordinarily deep snows sometimes accumulate on the upwind side ofmountain slopes during severe winter storms or on the downwind shores of large lakes during outbreaks of polar air. VI WIND Wind is the horizontal movement of air. It is named for the direction from which it comes—for example, a north wind comes from the north. In most places near theground, the wind speed averages from 8 to 24 km/h (from 5...

• Washington, D.

  structures built according to L’Enfant’s plan. During the War of 1812, British troops set fire to the White House, destroying its interior. President James Madison and hisfamily lived in the Octagon while the White House was being rebuilt. South of the Federal Triangle is the Mall, a narrow park stretching roughly 1.6 km (1 mi) from the Capitol to the Washington Monument. Although the Mall officially endsat 14th Street, landscaped greenery extends to the Potomac. The Washington Monument, whose m...

• Gold - chemistry.

  producers of gold during this period. Spain's domination in South America resulted, in the 16th century, in a large increase in gold produced in the New World; someresulted from simple seizure of gold from the Native Americans, who had long mined the metal. In the same century Mexico contributed about 9 percent of the totalworld production. Gold was discovered in Australia in February 1851, and rich fields were found there. By the middle of the 19th century the United States produced a considera...

• Millennium.

  Postmillennialism, also referred to as progressive millennialism, interprets the Bible less literally than premillennialism does. Postmillennialists regard the millennium as a1,000-year reign of Christian ideals that will end with the return of Christ. In this view, the millennium will not start suddenly through an apocalypse, but graduallythrough the efforts of human beings. Postmillennialists believe that through social reform and by upholding Christian ideals, the kingdom of God will be built...

• Nova Scotia - Geography.

  summer. Nova Scotia receives an average of more than 1,140 mm (45 in) of rain annually, with the Atlantic shore receiving 1,400 mm (55 in) or more. Most of the provincereceives about 1,900 mm (about 70 in) of snow, and considerable winter precipitation comes in the form of rain or ice storms. The average temperature in January, thecoldest month, is generally about -4°C (about 25°F) near the coast and somewhat colder toward the interior. The average temperature in July, the hottest month, isabout...

• Nova Scotia - Canadian History.

  summer. Nova Scotia receives an average of more than 1,140 mm (45 in) of rain annually, with the Atlantic shore receiving 1,400 mm (55 in) or more. Most of the provincereceives about 1,900 mm (about 70 in) of snow, and considerable winter precipitation comes in the form of rain or ice storms. The average temperature in January, thecoldest month, is generally about -4°C (about 25°F) near the coast and somewhat colder toward the interior. The average temperature in July, the hottest month, isabout...

• Ontario - Geography.

  governed Ontario’s initial settlement and development. The province’s most important river is the St. Lawrence. Its route was much improved and enlarged by dredgingand canal building in the mid-20th century. This enabled large ocean-going vessels to reach Great Lake ports ( see St. Lawrence Seaway). The Ottawa River was an important early route to the interior for fur traders and timber merchants. The Niagara River, because of its falls, is a great center of hydroelectric power as well as aninte...

• Ontario - Canadian History.

  governed Ontario’s initial settlement and development. The province’s most important river is the St. Lawrence. Its route was much improved and enlarged by dredgingand canal building in the mid-20th century. This enabled large ocean-going vessels to reach Great Lake ports ( see St. Lawrence Seaway). The Ottawa River was an important early route to the interior for fur traders and timber merchants. The Niagara River, because of its falls, is a great center of hydroelectric power as well as aninte...

• North Carolina - geography.

  The drainage divide in North Carolina follows the Blue Ridge range on the eastern margin of the mountain region. This is called the “Eastern Continental Divide.” West ofthis divide, rivers drain into the Mississippi River through the Tennessee River and other tributaries of the Ohio River. The French Broad, the largest, and the LittleTennessee flow into the Tennessee River. The New River flows into the Kanawha River of West Virginia which in turn flows into the Ohio River. Most of the state’s ri...

• North Carolina - USA History.

  The drainage divide in North Carolina follows the Blue Ridge range on the eastern margin of the mountain region. This is called the “Eastern Continental Divide.” West ofthis divide, rivers drain into the Mississippi River through the Tennessee River and other tributaries of the Ohio River. The French Broad, the largest, and the LittleTennessee flow into the Tennessee River. The New River flows into the Kanawha River of West Virginia which in turn flows into the Ohio River. Most of the state’s ri...

• 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...

• Alaska - geography.

  depression surrounded by highlands and have the coldest winter and hottest summer temperatures in Alaska. Once the Kuskokwim River passes through theKuskokwim Mountains, it forms the southern edge of a vast lake-studded alluvial plain bounded on the north by the Yukon River. This water-logged lowland is a majorsummer nesting area for birds. Fairbanks is the major city in this region, while Fort Yukon is the major community in the Yukon Flats and Bethel the largest settlementon the Lower Kuskokwi...

• Alaska - USA History.

  depression surrounded by highlands and have the coldest winter and hottest summer temperatures in Alaska. Once the Kuskokwim River passes through theKuskokwim Mountains, it forms the southern edge of a vast lake-studded alluvial plain bounded on the north by the Yukon River. This water-logged lowland is a majorsummer nesting area for birds. Fairbanks is the major city in this region, while Fort Yukon is the major community in the Yukon Flats and Bethel the largest settlementon the Lower Kuskokwi...

• California - geography.

  The Basin and Range province is an arid area of mountain ranges, basins, and deserts. In California it is represented primarily by parts of the Great Basin and SonoranDesert sections. Within the Great Basin lies Death Valley, whose lowest elevation, 86 m (282 ft) below sea level, is the lowest point in the Western Hemisphere. TheSonoran Desert section is characterized by numerous flat plains separated by low but rugged ranges. It includes the extensive Mojave, or Mohave, Desert. Also in thisprov...

• California - USA History.

  The Basin and Range province is an arid area of mountain ranges, basins, and deserts. In California it is represented primarily by parts of the Great Basin and SonoranDesert sections. Within the Great Basin lies Death Valley, whose lowest elevation, 86 m (282 ft) below sea level, is the lowest point in the Western Hemisphere. TheSonoran Desert section is characterized by numerous flat plains separated by low but rugged ranges. It includes the extensive Mojave, or Mohave, Desert. Also in thisprov...

• Iraq - country.

  The Euphrates begins in Turkey, crosses Syria, and enters Iraq at Abū Kam āl. The flow of the Euphrates into Iraq has been greatly reduced by dams built by Turkeyand Syria. The gradient of the Euphrates above the town of H īt, in west central Iraq, is steep. In the 2,640 km (1,640 mi) from its source in Turkey to H īt, the river fallsfrom 3,000 m (10,000 ft) to a low water elevation of 50 m (170 ft) above sea level, an average drop of 1 m per km (6 ft per mi). In Iraq below H īt the fall is very...

• Brazil - country.

  occasional droughts. Brazil contains a wealth of mineral and plant resources that have not yet been fully explored. It possesses some of the world’s largest deposits of iron ore and containsrich deposits of many other minerals, including gold and copper. Brazil’s fossil fuel resources are modest, but this limitation is offset by the considerable hydroelectricpotential of the nation’s many rivers. Although Brazil is an important producer of tropical crops, areas of highly fertile land are limited...

• 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...

• Vietnam - country.

  E Natural Resources Vietnam’s most valuable natural resource is its land, particularly the fertile, alluvial soils in the Red and Mekong deltas. Some 29 percent of the land is currently beingcultivated. Vietnam has some valuable mineral resources, including gold, iron, tin, zinc, phosphate, chromite, apatite, and anthracite coal. Most deposits are located in the northernpart of the country. Few attempts were made to extract these minerals until the French takeover of Vietnam at the end of the 1...

• Gravitation I INTRODUCTION Gravitation, the force of attraction between all objects that tends to pull them toward one another.

  precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...

• Gravitation - astronomy.

  precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...

• Earthquake.

  III CAUSES Most earthquakes are caused by the sudden slip along geologic faults. The faults slip because of movement of the Earth’s tectonic plates. This concept is called theelastic rebound theory. The rocky tectonic plates move very slowly, floating on top of a weaker rocky layer. As the plates collide with each other or slide past eachother, pressure builds up within the rocky crust. Earthquakes occur when pressure within the crust increases slowly over hundreds of years and finally exceeds...

• 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...

• Asteroiden - Astronomie.

  Oberfläche der S-Typ-Asteroiden ist deutlich heller als beim C-Typ und setzt sich vor allem aus Silicaten zusammen. Vermutlich bestehen sie aus dem gleichen Material wiedie gewöhnlichen Chondriten, eine weitere Klasse von Steinmeteoriten. M-Typ (M für Metall): Etwa 5 Prozent aller Asteroiden zählen zum M-Typ und haben einen hohen Metallgehalt, vor allem Eisen und Nickel. Sie stammen vermutlich aus denKernen ehemaliger, geschmolzener Planeten, deren Bestandteile sich entmischten und deren äußere...

• 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...

• Denver - geography.

  Denver is the center of professional sports in the Rocky Mountain region. Major league teams are the Denver Broncos (football), Colorado Rockies (baseball), DenverNuggets (basketball), and Colorado Avalanche (ice hockey). Coors Field (opened in 1995) is the home of the Colorado Rockies. The Broncos began play at the newlyconstructed Invesco Field at Mile High in 2001, and the Nuggets and Avalanche play at the Pepsi Center. The National Western Stock Show and Rodeo, one of thelargest such shows i...

• Roman Art and Architecture - History.

  Racecourses or circuses were also built in many cities for holding chariot races and horse races. Rome’s circus-shaped Piazza Navona occupies the site of one that wasbuilt during the reign ( AD 81-96) of the emperor Domitian. The largest circus in Rome, the Circus Maximus, held about 200,000 spectators. E Public Baths Large cities and small towns alike also had public baths ( thermae ); under the Republic they were generally made up of a suite of dressing rooms and bathing chambers with hot- ,...

• Tree - biology.

  The major parts of a tree are its roots, trunk, leaves, flowers, and seeds. These components play vital roles in a tree’s growth, development, and reproduction. A Roots Trees are held in place by anchoring organs called roots. In addition to anchoring the tree, roots also absorb water and minerals through tiny structures called roothairs. From the roots the water and mineral nutrients are carried upward through the wood cells to the leaves. Although the internal structure of most kinds of roots...

• Infrared Astronomy - astronomy.

  ft above sea level. With the launch of the Infrared Astronomical Satellite (IRAS), by the United States, the United Kingdom, and The Netherlands in 1983, infraredastronomy took another leap forward. This mission surveyed the entire sky at wavelengths of 12, 25, 60, and 100 microns (1 micron is a millionth of a meter) until itsonboard supply of liquid helium ran out. A short time later infrared astronomy was revolutionized by the first introduction of devices that could take infrared images. Thea...

• Nevada - geography.

  The Truckee, Carson, and Walker rivers flow out of the Sierra Nevada, thread their way around several of the desert ranges, and also end in closed basins. The Walkerflows into Walker Lake, the Carson into Lahontan Reservoir. The major part of the Truckee’s flow is now diverted to Lahontan Reservoir, although as required by lawsome of it empties into Pyramid Lake. Because these three streams flow constantly, the lakes into which they empty never dry up. Winnemucca Lake formerly receivedoverflow w...

• Nevada - USA History.

  The Truckee, Carson, and Walker rivers flow out of the Sierra Nevada, thread their way around several of the desert ranges, and also end in closed basins. The Walkerflows into Walker Lake, the Carson into Lahontan Reservoir. The major part of the Truckee’s flow is now diverted to Lahontan Reservoir, although as required by lawsome of it empties into Pyramid Lake. Because these three streams flow constantly, the lakes into which they empty never dry up. Winnemucca Lake formerly receivedoverflow w...

• Yangtze - Geography.

  A Agriculture and Industry Today about 400 million people, or about one-third of the population of China, live in the Yangtze Basin. Many are engaged in agriculture. The basin contributes nearlyhalf of China’s crop production, although only one-quarter of the basin is arable. The most fertile areas for farming are the Sichuan Basin, the plains between theYangtze and its tributary the Han, and the plains of the lower basin. In all about 40 percent of the cereals, more than 30 percent of the cott...

• Plate Tectonics.

  ridges. The Mid-Atlantic Ridge is an underwater mountain range created at a divergent plate boundary in the middle of the Atlantic Ocean. It is part of a worldwidesystem of ridges made by seafloor spreading. The Mid-Atlantic Ridge is currently spreading at a rate of 2.5 cm per year (1 in per year). The mid-ocean ridges today are60,000 km (about 40,000 mi) long, forming the largest continuous mountain chain on earth. Earthquakes, faults, underwater volcanic eruptions, and vents, oropenings, along...