109 résultats pour "scientific"
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Galileo
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INTRODUCTION
Galileo (1564-1642), Italian physicist and astronomer who, with German astronomer Johannes Kepler, initiated the scientific revolution that flowered in the work of
English physicist Sir Isaac Newton.
V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...
- Scientific Notation.
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KUHN, Thomas. The Nature and Necessity of Scientific Revolutions
toujours plus de raisons de se demander si elle peut possiblement être une image de la science. Après la périodepré-paradigme l'assimilation de toutes les nouvelles théories et de presque toutes nouvelles sortes de phénomènes aen fait exigé la destruction d'un paradigme précédent et un conflit conséquent entre écoles concurrentes de penséescientifique. L'acquisition cumulative de nouveautés non anticipées s'avère être exception quasiment inexistante à larègle du développement scientifique. L'ho...
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Isaac NewtonIINTRODUCTIONIsaac Newton (1642-1727), English physicist, mathematician, and natural philosopher, considered one of the most important scientists of all time.
B Calculus (Newton’s “Fluxional Method”) In 1669 Newton gave his Trinity mathematics professor Isaac Barrow an important manuscript, which is generally known by its shortened Latin title, De Analysi . This work contained many of Newton’s conclusions about calculus (what Newton called his “fluxional method”). Although the paper was not immediately published, Barrowmade its results known to several of the leading mathematicians of Britain and Europe. This paper established Newton as one of the...
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Isaac Newton.
B Calculus (Newton’s “Fluxional Method”) In 1669 Newton gave his Trinity mathematics professor Isaac Barrow an important manuscript, which is generally known by its shortened Latin title, De Analysi . This work contained many of Newton’s conclusions about calculus (what Newton called his “fluxional method”). Although the paper was not immediately published, Barrowmade its results known to several of the leading mathematicians of Britain and Europe. This paper established Newton as one of the t...
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La Psychiatrie est elle une science?
distinguish science from non-science. Philosophers of science now generally agree that the search for a demarcation criterion has failed. However, in other disciplines the search for a means of distinguishing science from pseudoscience continues. I review the current debate in psychology and psychiatry. Then, returning to philosophical work, I discuss and support accounts according to which 'science' is best considered a family resemblance term. This suggests that whether psychiatric research is...
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Galileo.
V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...
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Leonardo da Vinci.
Leonardo's stylistic innovations are even more apparent in The Last Supper, in which he represented a traditional theme in an entirely new way. Instead of showing the 12 apostles as individual figures, he grouped them in dynamic compositional units of three, framing the figure of Christ, who is isolated in the center of the picture.Seated before a pale distant landscape seen through a rectangular opening in the wall, Christ—who has just announced that one of those present will betrayhim—repres...
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Museum.
History museums are dedicated to promoting a greater appreciation and knowledge of history and its importance to understanding the present and anticipating thefuture. They range from historic sites and small historic house museums to large, encyclopedic institutions such as the Smithsonian’s National Museum of AmericanHistory in Washington, D.C. Many cities and states have historical societies that operate museums or historic sites. History museums usually collect a wide range ofobjects, includi...
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Araña - ciencias de la naturaleza.
Viuda negraLa viuda negra es una especie venenosa. Su veneno es una neurotoxina, que afecta a los nervios como los que controlan larespiración. En los seres humanos, la picadura de esta araña suele ser más tóxica para los niños que para los adultos.J.A.L. Cooke/Oxford Scientific Films Las arañas son por lo general carnívoras y se alimentan sólo de presas vivas. Pueden aplastarlas por medio de los pedipalpos, y los quelíceros casi siempre tienen glándulasque les permiten inyectar veneno. La picad...
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Mosca - ciencias de la naturaleza.
hay en la cabeza. La mosca abejorro tiene una larga probóscide que puede introducir hasta las profundidades de las flores para sorber néctar. El tábano tiene tambiénmandíbulas y maxilas, o piezas bucales en forma de daga, con las que perfora la piel de sus huéspedes. Los mosquitos hembra tienen un segundo juego de piezas bucalesperforadoras que introducen saliva en la herida para impedir que la sangre se coagule. Algunas moscas utilizan sus piezas bucales para perforar y vaciar el cuerpo de otro...
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Comte, Isidore-Auguste-Marie-François-Xavier
1 Life Auguste Comte was born in Montpellier, France. He attended the École Polytechnique, from which he was expelled in 1816, for political reasons. Comte's main concern throughout his life was resolving the political, social and moral problems caused by the French Revolution. To that end, he embarked upon an encyclopedic work, which he first conceived under the inspiration of Henri de Saint-Simon , for whom he worked as secretary from 1817 to 1824. At that time, he proposed several pla...
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Lewis and Clark Expedition.
took a small detachment into present-day north central Montana, thinking that the course of the Marias River might provide an American claim to fur-rich country inwhat is now the Canadian province of Alberta. In August the groups reunited on the Missouri River, near the mouth of the Yellowstone. They arrived in St. Louis onSeptember 23, 1806. C Relations with the Native Americans and Spanish The Lewis and Clark Expedition made a journey through the homelands of native people. What American expl...
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Lewis and Clark Expedition - explorer.
took a small detachment into present-day north central Montana, thinking that the course of the Marias River might provide an American claim to fur-rich country inwhat is now the Canadian province of Alberta. In August the groups reunited on the Missouri River, near the mouth of the Yellowstone. They arrived in St. Louis onSeptember 23, 1806. C Relations with the Native Americans and Spanish The Lewis and Clark Expedition made a journey through the homelands of native people. What American expl...
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Space Shuttle - astronomy.
The two SRBs, with their combined thrust of some 26 million newtons (about 5.8 million lb), provide most of the power for the first two minutes of flight. The SRBs takethe space shuttle to an altitude of 45 km (28 mi) and a speed of 4,973 km/h (3,094 mph) before they separate and fall back into the ocean to be retrieved,refurbished, and prepared for another flight. After the boosters fall away, the three main engines continue to provide thrust. These engines are clustered at the rear end of the...
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Manhattan Project - U.
other possible uses of nuclear energy, such as using uranium to operate large power plants or, perhaps, as power sources for ships or submarines. Then Nazi Germanyinvaded Poland on September 1, 1939, and Europe plunged into war. The scientists realized that any plans to build large-scale nuclear power plants would have to waituntil the war was over. Two weeks after the invasion of Poland, Hitler made a radio speech in which he threatened Britain with “a weapon against which there is no defense.”...
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Psychology.
Clinical psychology is dedicated to the study, diagnosis, and treatment of mental illnesses and other emotional or behavioral disorders. More psychologists work in this field than in any other branch of psychology. In hospitals, community clinics, schools, and in private practice, they use interviews and tests to diagnose depression,anxiety disorders, schizophrenia, and other mental illnesses. People with these psychological disorders often suffer terribly. They experience disturbing symptoms t...
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Global Warming.
some of the warming influence of increasing greenhouse gases. A1 Carbon Dioxide Carbon dioxide is the second most abundant greenhouse gas, after water vapor. Carbon dioxide constantly circulates in the environment through a variety of naturalprocesses known as the carbon cycle. It is released into the atmosphere from natural processes such as eruptions of volcanoes; the respiration of animals, whichbreathe in oxygen and exhale carbon dioxide; and the burning or decay of plants and other organic...
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Geographic Exploration.
The commercial reason for exploration has been a consistent driving force. In 1492 the great navigator Christopher Columbus sailed west across the Atlantic Oceanseeking a new, shorter, and cheaper route to reach the riches of East Asia, and Portuguese explorer Vasco da Gama circumnavigated Africa for much the same reason.Yet similar investigations of the profitable eastern trade had already been made by Arab sailors. Arab trading ships were sailing from the Arabian Sea to southeasternAsia probab...
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Geographic Exploration - explorer.
The commercial reason for exploration has been a consistent driving force. In 1492 the great navigator Christopher Columbus sailed west across the Atlantic Oceanseeking a new, shorter, and cheaper route to reach the riches of East Asia, and Portuguese explorer Vasco da Gama circumnavigated Africa for much the same reason.Yet similar investigations of the profitable eastern trade had already been made by Arab sailors. Arab trading ships were sailing from the Arabian Sea to southeasternAsia probab...
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Fruto - ciencias de la naturaleza.
penetra en el óvulo, donde puede fecundarlo. Si lo fecunda, el óvulo se transforma en semilla y el receptáculo que protege el ovariose ensancha y forma la carne o pulpa del fruto.© Microsoft Corporation. Reservados todos los derechos. En los casos típicos, el fruto se limita al ovario maduro, como ocurre en la vaina del guisante (chícharo); en cambio, la manzana incluye ovario y receptáculo —el conjuntode las demás piezas florales soldadas—; la fresa es en realidad una infrutescencia formada por...
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Alternative Medicine.
The field of chiropractic was founded by David Daniel Palmer in the 1890s. He believed that joint subluxation, or a partial dislocation, is a causal factor in disease andthat removal of the subluxation by thrusting on the bony projections of the vertebrae restores health. In addition to manipulating and adjusting bone and tissue, particularly in the spinal column, chiropractors use a variety of manual, mechanical, and electrical treatments.Chiropractors are most widely recognized for providing d...
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Condillac, Etienne Bonnot de
concerning Human Understanding (1689) by Pierre Coste and read Voltaire's books on Newton. He was the contemporary of such Enlightenment luminaries as Helvetius, Diderot, Buffon, La Mettrie and Holbach. Voltaire and Diderot both expressed the very highest regard for his writings. Condillac was on friendly terms with Rousseau, and was frequently to be seen at the salons in and around Paris where so much of the intellectual activity of the Enlightenment took place. He spent nine years (1758-67...
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Boutroux, Émile
entirely a priori, and because reality is incommensurable and irreducible to mathematical necessity. As mathematics is applied to experience, the laws become more determinate and particular, and thereby less necessitating. It is an error of scientism to confuse determinism with necessitarianism. Science, in its effort to reduce experience to the mathematical, loses its sense of the radical contingency at work in nature; it generalizes and takes things to extremes in transforming its useful regul...
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Gramíneas - ciencias de la naturaleza.
Otra aplicación de las gramíneas de considerable importancia económica en muchas partes del mundo es la plantación de céspedes. Las gramíneas perennes son apropiadaspara este fin, porque no pierden los meristemos basales (los puntos de crecimiento) durante la siega. El llamado pasto bravo, por ejemplo, es originario de Argentina,Bolivia y Chile. En condiciones especiales de suelo o de exposición poco apropiadas para las especies más comunes se emplean otras mezclas. Así, en regiones pocolluviosa...
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Reproducción - ciencias de la naturaleza.
distintas. La mayoría de los animales y plantas pluricelulares tienen una forma de reproducción sexual más compleja en la que se diferencian de forma específica las célulasreproductoras o gametos masculino y femenino. Ambas se unen para formar una única célula conocida como cigoto, que sufrirá divisiones sucesivas y originará unorganismo nuevo. Para definir la unión de los gametos masculino y femenino se utiliza el término fecundación. En esta forma de reproducción sexual, la mitad de los genesd...
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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...
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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...
- UNESCO (United Nations Educational, Scientific and Cultural Organization), organisme spécialisé de l'ONU, fondé en 1946.
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Brandenburg Technical University Cottbus
Department 1, Institute of Mathematics
Chair for Numerical Mathematics an Scientific Computing
Prof.
) 1 = 1 ; 2= 3 = 2i Eigenvectors: 0 @ 1 1 1 0 1 5 0 1 1 1 A ~x= ~ 0 1 = 1: 0 @ 0 1 1 0 0 5 0 1 2 1 A ; ~x =t(1 ;0 ;0) T 1 = 2 i: 0 @ 1 2i 1 1 0 1 2i 5 0 1 1 2i 1 A ~x= ~ 0 0 @ 1 2i 1 1 0 1 1 2i 0 0 0 1 A ~x= ~ 0 ; ~x = 2i 1 2i; 1 2i; 1 T 1 = 2i: 0 @ 1 + 2 i 1 1 0 1 + 2 i5 0 1 1 + 2 i1 A ~x= ~ 0 0 @ 1 + 2 i1 1 0 1 1 + 2 i 0 0 0 1 A ~x= ~ 0 ; ~x = 2i 1 + 2 i; 1 + 2 i;1 T H 13.3: det(A E ) = det 1 1 1 3 = (1 )(3 ) 1 = 2 4 + 2 : Eigenvalues: 1= 2 = 2 p 2 E...
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Nanotechnology.
ever-finer method of reducing material to the nanoscale size. Instead, nanostructures would be assembled atom by atom and molecule by molecule, from the atomiclevel up, just as occurs in nature. However, assembly at this scale has its own challenges. In school, children learn about some of these challenges when they study the random Brownian motion seen in particles suspended in liquids such as water. Theparticles themselves are not moving. Rather, the water molecules that surround the particles...
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Welfare.
industrializing societies. Governments typically financed social insurance programs with tax funds and direct levies on the wages of potential recipients. Social insurancereplaced part of incomes lost when workers became disabled, were laid off, or had reached an age that forced them out of the labor market. Later, governments of Germany, France, Belgium, Sweden, and other countries developed forms of social insurance that provided population-wide, or universal,coverage. Such forms included chil...
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Anthropology.
humans, such as tools, pottery, and buildings) and human fossils (preserved bones). They also examine past environments to understand how natural forces, such as climate and available food, shaped the development of human culture. Some archaeologists study cultures that existed before the development of writing, a time knownas prehistory . The archaeological study of periods of human evolution up to the first development of agriculture, about 10,000 years ago, is also called paleoanthropology....
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Apollo Program - astronomy.
Moon’s orbit; rendezvousing and docking with the CSM; and finally, setting a course home to Earth. On return to Earth, the spacecraft was slowed by drag from Earth’satmosphere and by parachutes (just before splashdown), before landing in the ocean. The transit time to and from the Moon was approximately three days each way.Depending on the specific mission, the time in lunar orbit ranged from less than one day for Apollo 8 to over six days for the final three missions, and the time on thelunar s...
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Apollo Program - U.
Moon’s orbit; rendezvousing and docking with the CSM; and finally, setting a course home to Earth. On return to Earth, the spacecraft was slowed by drag from Earth’satmosphere and by parachutes (just before splashdown), before landing in the ocean. The transit time to and from the Moon was approximately three days each way.Depending on the specific mission, the time in lunar orbit ranged from less than one day for Apollo 8 to over six days for the final three missions, and the time on thelunar s...
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Renaissance
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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...
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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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Archaeology.
Prehistoric archaeology is practiced by archaeologists known as prehistorians and deals with ancient cultures that did not have writing of any kind. Prehistory, a term coined by 19th-century French scholars, covers past human life from its origins up to the advent of written records. History—that is, the human past documented insome form of writing—began 5000 years ago in parts of southwestern Asia and as recently as the late 19th century AD in central Africa and parts of the Americas. Becaus...
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Hongos - ciencias de la naturaleza.
Ciertos hongos que viven en el suelo son predadores activos y atrapan organismos microscópicos como amebas y nematodos. Las presas se capturan por medio de unamalla de hifas, recubierta por una sustancia adhesiva, a la que queda pegada la presa. Las hifas penetran en el microorganismo, crecen y se ramifican dentro de su cuerpoabsorbiendo nutrientes hasta matarlo. 3 ESTRUCTURA Estructura de un hongoLos hongos están constituidos por tubos filamentosos llamados hifas. En muchas especies las parede...
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Hongos - ciencias de la naturaleza.
Ciertos hongos que viven en el suelo son predadores activos y atrapan organismos microscópicos como amebas y nematodos. Las presas se capturan por medio de unamalla de hifas, recubierta por una sustancia adhesiva, a la que queda pegada la presa. Las hifas penetran en el microorganismo, crecen y se ramifican dentro de su cuerpoabsorbiendo nutrientes hasta matarlo. 3 ESTRUCTURA Estructura de un hongoLos hongos están constituidos por tubos filamentosos llamados hifas. En muchas especies las parede...
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Astronaut - astronomy.
Every operation during a flight is important and interesting, but many might be boring to an observer. Much of an astronaut’s job is entering computer instructions,preparing samples, making measurements, recording data, fixing what breaks, and adjusting the checklist when something unexpected happens. Sometimes astronautsretrieve or repair satellites, rendezvous or dock with other spacecraft, and do important emergency repairs. The adaptability of the human crew is crucial to the successof missi...
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Culture.
form of knowledge, such as scientific discoveries; objects, such as works of art; and traditions, such as the observance of holidays. C1 Ethnocentrism and Cultural Relativism Self-identity usually depends on culture to such a great extent that immersion in a very different culture—with which a person does not share common ways of life orbeliefs—can cause a feeling of confusion and disorientation. Anthropologists refer to this phenomenon as culture shock. In multicultural societies —societies s...
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Anatomie - biologie.
Das Nervensystem lässt sich in zwei Teilbereiche untergliedern: Das willkürliche Nervensystem erlaubt die bewusste Steuerung der Muskeln, das autonome oderunwillkürliche Nervensystem dagegen lässt sich mit dem Willen nicht beeinflussen und steuert die Tätigkeit von Herz, glatter Muskulatur und Drüsen. Innerhalb desunwillkürlichen Nervensystems gibt es eine weitere Zweiteilung in sympathisches und parasympathisches System. Viele Muskeln und Drüsen – allerdings nicht alle – werdenvon zwei Nerven v...
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Albert Einstein
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INTRODUCTION
Albert Einstein (1879-1955), German-born American physicist and Nobel laureate, best known as the creator of the special and general theories of relativity and for his
bold hypothesis concerning the particle nature of light.
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...
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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...
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Medio ambiente - ciencias de la naturaleza.
aproximadamente. Lo significativo de este cambio es que puede provocar un aumento de la temperatura de la Tierra a través del proceso conocido como efecto invernadero.El dióxido de carbono atmosférico tiende a impedir que la radiación de onda larga escape al espacio exterior; dado que se produce más calor y puede escapar menos, latemperatura global de la Tierra aumenta. Un calentamiento global significativo de la atmósfera tendría graves efectos sobre el medio ambiente. Aceleraría la fusión de l...
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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...
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National Parks and Preserves.
Some ibex raised in Italy’s 700 sq km (220 sq mi) Gran Paradiso National Park (1922) were transferred to aid herd restoration elsewhere in the country. Switzerlandreturned lynx to Swiss National Park to keep red deer populations in check. The growth of national parks also enabled many European countries to restore forests thathad given way to industrialization by the early 20th century. Africa’s wildlife was hunted heavily from the late 19th century well into the 20th century. By 1920 big-game h...
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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...
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Captain James Cook.
After leaving Tahiti, the expedition headed north into uncharted territory. After becoming the first Europeans to sight the Hawaiian Islands (which Cook named theSandwich Islands) in 1778, they sailed along the west coast of Canada and Alaska. Twice Cook explored inlets that offered some promise of a Northwest Passage, but tono avail. After sailing through the Bering Strait into the Arctic Sea and briefly scouting the Asian side of the strait, Cook decided to winter in the Hawaiian Islands. Hein...