90 résultats pour "wave"

• Immigration - U.

  1655, only to lose all of their North American colonies to the British in 1664. These early colonies were often quite cosmopolitan, drawing settlers from many nations.When the English seized New Amsterdam, the city was home to perhaps 1500 residents, including Walloons, Huguenots, Swedes, Dutchmen, and African Americans. C The French and Spanish The French and Spanish also established colonies in North America. The Spanish established the oldest permanent European settlement in Saint Augustine,...

• Meteorology.

  to find the corresponding relative humidity and dew-point temperature. III SPECIAL METEOROLOGICAL INSTRUMENTS Meteorologists have developed several sophisticated instruments that measure multiple physical characteristics of the air simultaneously and at more than one location.The most important of these special instruments are radiosondes, Doppler radar, and weather satellites. A Radiosonde A radiosonde measures air temperature, air pressure, and humidity from the earth’s surface up to an alt...

• Percy Bysshe Shelley: Ode to the Westwind (Sprache & Litteratur).

  Than thou, O uncontrollable! If evenI were as in my boyhood, and could be The comrade of thy wanderings over Heaven,As then, when to outstrip thy skiey speedScarce seemed a vision; I would ne’er have striven As thus with thee in prayer in my sore need.Oh, lift me as a wave, a leaf, a cloud!I fall upon the thorns of life! I bleed! A heavy weight of hours has chained and bowedOne too like thee: tameless, and swift, and proud. V Make me thy lyre, even as the forest is:What if my leaves are falling...

• Republic (government).

  South African Republic (1852) and the Orange Free State (1854), were finally annexed by Britain after the Boer War (1899-1902). Both in the United States and otherrepublics, however, the passage of the century was generally marked by democratization of the electoral process through the enlargement of the electorate. Two waves of new-state formations occurred in the 20th century—the first one after World War I, the second after World War II. Most of the newly independent statesestablished themsel...

• 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...

• Bac L anglais

  12AN1LME1 Page : 2/4 Joseph Netmaker brought the letter out to me. Winter had just started to settle itself into the country. Joseph walked on snowshoes from the town. ‘This is for you, Niska,’ he said. ‘It is from the Canadian boss, their hookimaw.’ As soon as I saw the brown letter, the English words written upon it, I knew what it contained. I sat down beside the fire and stirred at it with a stick while Joseph read, first out 5 loud and in his stumbling English, then for me in our l...

• Wetland.

  Other plants and animals have special adaptations suited for living in a wet environment. Most emergent plants have air spaces in their stems that enable oxygen to betransported to roots that grow in sediments with no oxygen. Some of the trees that grow in swamps form a set of roots above the soil surface or above the water thatallows them to get oxygen to the lower roots. In saltwater wetlands, specialized cells can limit the amount of salt that enters a plant, or specialized organs can excrete...

• Cognitive Psychology.

  full richness of people’s cognitive experiences. Describing the act of remembering as a process of storage and retrieval, for example, neglects the subjective experienceof remembering. Another criticism is that information-processing theory may not reflect how the brain actually works. Newer models, such as the parallel distributedprocessing model, try to address this criticism by drawing on studies of brain structure and function. Psychologists continue to debate the adequacy of the information...

• From Bulfinch's Mythology: Prometheus and Pandora - anthology.

  The world being thus furnished with inhabitants, the first age was an age of innocence and happiness, called the Golden Age. Truth and right prevailed, though not enforced by law, nor was there any magistrate to threaten or punish. The forest had not yet been robbed of its trees to furnish timbers for vessels, nor had men builtfortifications round their towns. There were no such things as swords, spears, or helmets. The earth brought forth all things necessary for man, without his labour inplo...

• 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...

• 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...

• Submarine.

  B Propulsion Modern submarines use either diesel-electric or nuclear power to drive the sub's propeller and to provide internal electric power. Diesel-electric power emerged as themost efficient propulsion system for submarines in the early 20th century, following unsuccessful attempts to use steam or gasoline power. While on the surface, thesubmarine uses a diesel engine to drive the propeller and generate electricity. When submerged, a battery-driven electrical motor takes over for propulsion...

• 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...

• 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...

• 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...

• Europe .

  D Vegetation Although much of Europe, particularly the west, was originally covered by forest, the vegetation has been transformed by human habitation and the clearing of land.Only in the most northerly mountains and in parts of north central European Russia has the forest cover been relatively unaffected by human activity. On the otherhand, a considerable amount of Europe is covered by woodland that has been planted or has reoccupied cleared lands. The largest vegetation zone in Europe, cuttin...

• Europe - Geography.

  D Vegetation Although much of Europe, particularly the west, was originally covered by forest, the vegetation has been transformed by human habitation and the clearing of land.Only in the most northerly mountains and in parts of north central European Russia has the forest cover been relatively unaffected by human activity. On the otherhand, a considerable amount of Europe is covered by woodland that has been planted or has reoccupied cleared lands. The largest vegetation zone in Europe, cuttin...

• Cuba - country.

  Only two land mammals, the hutia, or cane rat, and the solenodon, a rare insectivore that resembles a rat, are known to be indigenous. The island has numerous batsand nearly 300 kinds of birds, including vultures, wild turkeys, quail, finches, gulls, macaws, parakeets, and hummingbirds. The bee hummingbird of Cuba is thesmallest bird in the world. Among the few reptiles are tortoises, caimans, the Cuban crocodile, and a species of boa that can attain a length of 3.7 m (12 ft). More than700 speci...

• Spain - country.

  B Natural Resources Spain has a number of mineral resources. The largest known deposits are of iron ore, zinc, and lead. Spain also produces significant quantities of copper and mercury.These deposits are mined mainly in Huelva province in southwestern Spain, around Cartagena on the Mediterranean, and at various points along the Bay of Biscay inthe north. Additionally, uranium is mined in the region of Extremadura, near the Portuguese frontier, where pyrites, fluorspar, gypsum, tungsten, and po...

• LIGHT, RADIATION AND TELESCOPES

  As with all waves, light waves have a certain wavelength. This is the distance between the crests, or high points, of two successive waves; or between the troughs, or low points, of two successive waves. Alternatively, we can describe a wave by its frequency, the number of complete waves passing a certain point every second. A long wavelength means a low frequency, because fewer waves pass per second; and a short wavelength means a high frequency, because more waves pass every second. Light, h...

• Tsunami.

• 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...

• 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...

• Atom - chemistry.

  Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions. A Atomic Number Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral,the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties ofthe atom. The ligh...

• Cellular Radio Telephone.

  There were more than 120 million wireless subscribers in the United States in 2001, according to the Cellular Telecommunications and Internet Association, with thenumber of new users increasing significantly each year. Forecasters and regulators did not anticipate this growth, however. Network equipment and start-up costs weresubstantial, and the cost to consumers was high. Providers had limited their networks to a small group of high-volume business users. Eventually, the providersrecognized th...

• Atom I INTRODUCTION Water Molecule A water molecule consists of an oxygen atom and two hydrogen atoms, which are attached at an angle of 105°.

  spontaneously break apart and change, or decay, into other atoms. Unlike electrons, which are fundamental particles, protons and neutrons are made up of other, smaller particles called quarks. Physicists know of six different quarks.Neutrons and protons are made up of up quarks and down quarks —two of the six different kinds of quarks. The fanciful names of quarks have nothing to do with their properties; the names are simply labels to distinguish one quark from another. Quarks are unique amo...

• Le trip-hop

  Le premier album de Massive Attack — Blue Lines (1991) et ses morceaux « Safe From Harm » ou « Unfinished Sympathy » — est couramment considéré comme l’acte fondateur de ce courant musical dont Bristol est l’épicentre. Parallèlement, une cohorte de labels essaime, parmi lesquels Ninja Tune, Cup of Tea et surtout Mo’Wax, qui publie les débuts décisifs de DJ Shadow et du Japonais DJ Krush. Autre citoyen de Bristol (et compagnon de route de Massive Attack), le rap...

• 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...

• Bob Dylan - Musik.

  To RamonaMy Back PagesIt ain't Me Babe 1965 Bringing It All Back Home/Subterranean HomesickBlues Subterranean Homesick BluesMaggie's FarmLove Minus Zero/No LimitMr. Tambourine ManIt's Alright, Ma (I'm Only Bleeding)It's All Over Now, Baby Blue 1965 Highway 61 Revisited Like a Rolling StoneTombstone BluesIt Takes a Lot to Laugh, It Takes aTrain to CryHighway 61 RevisitedJust Like Tom Thumb's BluesDesolation Row 1966 Blonde on Blonde Rainy Day Women #12 & 35One of Us Must Know (Sooner orLater)I W...

• Sun - astronomy.

  A The Sun’s Place in the Milky Way The Milky Way Galaxy contains about 400 billion stars. All of these stars, and the gas and dust between them, are rotating about a galactic center. Stars that arefarther away from the center move at slower speeds and take longer to go around it. The Sun is located in the outer part of the galaxy, at a distance of 2.6 × 10 17 km (1.6 × 10 17 mi) from the center. The Sun, which is moving around the center at a velocity of 220 km/s (140 mi/s), takes 250 million y...

• Extinction (biology) - biology.

  III ROLE OF MASS EXTINCTION IN EVOLUTION Historically biologists—most famous among them British naturalist Charles Darwin—assumed that extinction is the natural outcome of competition between newlyevolved, adaptively superior species and their older, more primitive ancestors. These scientists believed that newer, more highly evolved species simply drove less well-adapted species to extinction. That is, historically, extinction was thought to result from evolution. It was also thought that this...

• 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...

• Relativity I INTRODUCTION Albert Einstein In 1905 German-born American physicist Albert Einstein published his first paper outlining the theory of relativity.

  in calculating very large distances or very large aggregations of matter. As the quantum theory applies to the very small, so the relativity theory applies to the verylarge. Until 1887 no flaw had appeared in the rapidly developing body of classical physics. In that year, the Michelson-Morley experiment, named after the American physicistAlbert Michelson and the American chemist Edward Williams Morley, was performed. It was an attempt to determine the rate of the motion of the earth through t...

• Conservation.

  cancers, Hodgkin’s disease and leukemia. Unfortunately, human activities have greatly reduced biodiversity around the world. The 20th century encompasses one of the greatest waves of extinction, orelimination of species, to occur on the planet. The greatest threat to biodiversity is loss of habitat as humans develop land for agriculture, grazing livestock, industry,and habitation. The most drastic damage has occurred in the tropical rain forests, which cover less than seven percent of the Earth’...

• Fidel Castro.

  result, Castro formed a radical branch of the Ortodoxo Party called the Radical Action Orthodox wing. This organization supported Chibás in the 1948 election. PrioSocarrás won the election, despite Castro’s efforts. After Chibás committed suicide in 1951, Castro believed he should become the leader of the Ortodoxo Party and ran for a seat in the Cuban House of Representatives inthe 1952 election. Before that election could occur, however, General Fulgencio Batista staged a bloodless coup d’etat...

• Kazakhstan - country.

  mismanagement. Between 1949 and 1991 the Soviet government conducted about 70 percent of all of its nuclear testing in Kazakhstan, mostly in the northeastern area near the city ofSemipalatinsk (now Semey). Nearly 500 nuclear explosions occurred both above and below ground near Semipalatinsk, while more than 40 nuclear detonationsoccurred at other testing grounds in western Kazakhstan and in the Qyzylqum desert. More than 1 million of Kazakhstan’s inhabitants were exposed to dangerous levelsof ra...

• Middle East - Geography.

  though overall they have improved considerably since the 1970s. This variation reflects the different levels of wealth and development in countries of the Middle East. Inthe highly developed country of Israel the infant mortality rate was 8 deaths per 1000 live births in 1997. By comparison, the rate per 1000 live births was 71 in less-developed Egypt and 75 in Yemen. A Ethnic Groups and Languages Arabs make up the majority of the people of the Middle East, accounting for almost the entire popu...

• Chemistry - chemistry.

  parts of oxygen by weight, which is a ratio of about 1 to 8, regardless of whether the water came from the Mississippi River or the ice of Antarctica. In other words, acompound has a definite, invariable composition, always containing the same elements in the same proportions by weight; this is the law of definite proportions. Many elements combine in more than one ratio, giving different compounds. In addition to forming water, hydrogen and oxygen also form hydrogen peroxide.Hydrogen peroxide h...

• World War II .

  the Nazi-Soviet Pact was signed. In the part published the next day, Germany and the Soviet Union agreed not to go to war against each other. A secret protocol gaveStalin a free hand in Finland, Estonia, Latvia, eastern Poland, and eastern Romania. See also German-Soviet Nonaggression Pact. III MILITARY OPERATIONS In the early morning hours of September 1, 1939, the German armies marched into Poland. On September 3 the British and French surprised Hitler by declaring war onGermany, but they...