144 résultats pour "matter"
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Elementary Particles
I
INTRODUCTION
Structure of Matter
Modern physics has revealed successively deeper layers of structure in ordinary matter.
The most fundamental particles that make up matter fall into the fermion category. These fermions cannot be split into anything smaller. The particles that carry theforces acting on matter and antimatter are bosons called force carriers. Force carriers are also fundamental particles, so they cannot be split into anything smaller.These bosons carry the four basic forces in the universe: the electromagnetic, the gravitational, the strong (force that holds the nuclei of atoms together), and the wea...
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Matta
par Michel Ragon
Roberto Sebastian Matta Echaurren, dit Matta, est né à Santiago du Chili.
par Michel Ragon
- Matta ( Roberto Matta Echaurren.
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Dark Matter - astronomy.
observed, and the measured frequency of such events has placed limits on how much dark matter can take the form of MACHOs. From the observations that have beenmade by astronomers, it is now known that MACHOs cannot be the dominant constituent of dark matter. There are simply not enough such gravitational lenses. Physicists suspect that a more exotic form of cold dark matter must exist. This form is not baryonic. Like neutrinos, this form barely interacts with ordinary matter, butis some type of...
- Matta
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Matta, Roberto - vie et oeuvre du peintre.
5 EXIL ET ENGAGEMENT Matta, l'Inconnu Les formes organiques, symboliques et mécaniques qui se juxtaposent et s'entrecroisent dans les tableaux du peintre chilien Roberto Matta Echaurren contribuent à donner à son œuvre picturalesa forte charge de mystère. Membre du mouvement surréaliste, Matta a voulu réhabiliter le rôle du hasard et de l'inconscient dans le processus de création.Roberto Matta Echaurren, l'Inconnu,1951. Musée d'Art moderne, palais Liechtenstein, Vienne, Autriche.© 2008 Artists...
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Quark
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INTRODUCTION
Quark, smallest known building block of matter.
Constituents of MatterMatter is composed of tiny particles called quarks. Quarks come in six varieties: up (u), down (d), charm (c), strange (s),top (t), and bottom (b). Quarks also have antimatter counterparts called antiquarks (designated by a line over the lettersymbol). Quarks combine to form larger particles called baryons, and quarks and antiquarks combine to form mesons.Protons and neutrons, particles that form the nuclei of atoms, are examples of baryons. Positive and negative kaons aree...
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Quantum Theory
I
INTRODUCTION
Quantum Theory, in physics, description of the particles that make up matter and how they interact with each other and with energy.
electron in the same way a particle with momentum would: It bumps the electron and changes the electron’s path. The light is also affected by the collision as though itwere a particle, in that its energy and momentum changes. Momentum is a quantity that can be defined for all particles. For light particles, or photons, momentum depends on the frequency, or color, of the photon, which in turndepends on the photon’s energy. The energy of a photon is equal to a constant number, called Planck’s cons...
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- Vanhanen, Matti
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C'est le lendemain, le lundi, que Matt et moi sommes retournés chez Jack pour l'interviewer en
privé ; c'est le lundi qu'il nous a dit tant de choses à propos de Ruchele.
J'ai ajouté aprèsunbref silence, Çavamourir uniquement sivous nenous parlez pas. Bien, a-t-elle dit.Laligne estrestée mortependant uneminute etpuis elleadit, Sije vous vois, ce sera dans unrestaurant, monbeau-frère estmalade, jene peux pasrecevoir desgens ici. Très bien, ai-jedit.C'est indifférent pournous. Nousvousretrouverons oùvous voudrez, dites- nous simplement où. En silence, j'articulais gagnépourMatt. Ouais ! s'estécrié Matt. OK, adit Meg, jevous verrai demain, mercredi. Téléphonez-moi c...
- Roberto Matta.
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Interstellar Matter - astronomy.
silhouette of a cloud of dust. At other times, it blocks only a percentage of the light from behind it, a process known by astronomers as extinction . The long, narrow dark lanes in the Milky Way as seen from Earth are examples of extinction. The amount of extinction is different for different wavelengths of light. A2 Reddening Starlight that does not get completely absorbed by interstellar dust can still be changed by the dust’s effects. As light passes through less dense patches of interstel...
- Biondi, Matt - sport.
- MATTI. Personnage de la pièce de Bertolt Brecht
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Thermodynamics
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INTRODUCTION
Thermodynamics, field of physics that describes and correlates the physical properties of macroscopic systems of matter and energy.
Carnot EngineThe idealized Carnot engine was envisioned by the French physicist Nicolas Léonard Sadi Carnot, who lived during theearly 19th century. The Carnot engine is theoretically perfect, that is, it converts the maximum amount of energy intomechanical work. Carnot showed that the efficiency of any engine depends on the difference between the highest andlowest temperatures reached during one cycle. The greater the difference, the greater the efficiency. An automobileengine, for example, wou...
- Vanhanen, Matti - biographie.
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- Encyclopedia of Philosophy: Matter, Form, Substance, and Accident (Aquinas)
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avec son appareil photo et j'ai profité de la pause dans la conversation pour annoncer à Malcia
que Matt venait d'être classé parmi les dix meilleurs photographes de mariage du pays.
La tristesse pesaittoujours, deuxjours plustard, quand noussommes allésàHaïfa pour prendre desphotos deJosef Adler. Nous avions passélapremière moitiédecesamedi chezElkana pouruneautre réunion familiale gigantesque, undéjeuner auquelunplus grand nombre encorequeladernière fois, semblait-il, decousins germains, decousins audeuxième ettroisième degré,avaient puvenir. Cette fois,lasœur d'Elkana, Bruria,étaitvenue deHaïfa. C'était unefemme àla charpente délicate, auxcheveux noirscoupés àla page. E...
- Matt Biondi - Sport.
- Matti Nykänen - Sport.
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Matt voulait savoir ce qu'on ressentait, quelle était l'atmosphère dans la ville au cours de ces
journées qui ont suivi la première Aktion.
Cela nelaissait queShmiel qui,quoi qu'ilaitpu luiarriver jusqu'en 1944,étaitalors àdes années-lumière, semblait-il,dumonde de1939, lorsqu'il écrivaitleslettres oùl'on pouvait encore, c'étaitmonimpression, entendresavoix :fière, désespérée, dictatoriale,amère,pleine d'espoir, épuisée,troublée. Qu'était-il arrivé,essayais-je deconcevoir enécoutant les Australiens, àOncle Shmiel ? Jack pensait, avait-ildit,qu'il avait étéarrêté aucours delaseconde Aktion, puisque plus personne nel'avait revuensuite...
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Big Bang Theory - astronomy.
hydrogen atoms. Hydrogen atoms can only absorb and emit specific colors, or wavelengths, of light. The formation of atoms allowed many other wavelengths of light,wavelengths that had been interfering with the free electrons prior to the cooling of the universe, to travel much farther than before. This change set free radiation thatwe can detect today. After billions of years of cooling, this cosmic background radiation is at about 3 K (-270°C/-454°F).The cosmic background radiation was first d...
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Sewage Disposal.
greater load on the piping system and the treatment plant. The amount of storm-water drainage to be carried away depends on the amount of rainfall as well as on the runoff or yield of the watershed ( see Drainage). A typical metropolitan area discharges a volume of wastewater equal to about 60 to 80 percent of its total daily water requirements, the rest being used for washingcars and watering lawns, and for manufacturing processes such as food canning and bottling. B Composition The composi...
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Radioactivity
I
INTRODUCTION
Marie Curie
Working with her husband, Pierre Curie, French physicist Marie Curie discovered the radioactive elements polonium and
radium in 1898.
Rutherford when he allowed an alpha-emitting substance to decay near an evacuated thin-glass vessel. The alpha particles were able to penetrate the glass and werethen trapped in the vessel, and within a few days the presence of elemental helium was demonstrated by use of a spectroscope. Beta particles were subsequentlyshown to be electrons, and gamma rays to consist of electromagnetic radiation of the same nature as X rays but of considerably greater energy. A The Nuclear Hypothesis Rutherford...
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Western Philosophy.
the popular belief in personal deities, but he failed to explain the way in which the familiar objects of experience could develop out of elements that are totally differentfrom them. Anaxagoras therefore suggested that all things are composed of very small particles, or “seeds,” which exist in infinite variety. To explain the way in whichthese particles combine to form the objects that constitute the familiar world, Anaxagoras developed a theory of cosmic evolution. He maintained that the activ...
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Ocean and Oceanography.
of sediment. When studied in sedimentary core samples, which can represent many millions of years of deposits, they provide a detailed and continuous history of theearth’s environmental changes. The record is particularly informative for the most recent 2 million to 5 million years, during which major fluctuations in global climatehave occurred. Successive ice ages can be traced by the relative scarcity or abundance of the shells of warm-water and cold-water diatoms in various layers of asedimen...
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Ocean and Oceanography - Geography.
of sediment. When studied in sedimentary core samples, which can represent many millions of years of deposits, they provide a detailed and continuous history of theearth’s environmental changes. The record is particularly informative for the most recent 2 million to 5 million years, during which major fluctuations in global climatehave occurred. Successive ice ages can be traced by the relative scarcity or abundance of the shells of warm-water and cold-water diatoms in various layers of asedimen...
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drôle à part entière, une histoire qui est régulièrement racontée pour éclairer ou peut-être
préserver un certain aspect de la personnalité de mon grand-père décédé.
Et l'on nesait vraiment jamais.Ilya peut-être quinzeans,mon plusjeune frère,quiétait alors assistant pourlescostumes pourlesfilms deWoody Allen,cherchait destissus dansune boutique maléclairée, unendroit rempliderouleaux detissus, danslequartier delaconfection à New York. Ilaremarqué quelevieil homme aucomptoir portaituntatouage surl'avant-bras et ila engagé laconversation aveclui.Mon frère amentionné, aucours decette conversation, le fait que desparents ànous quiavaient péridans ledésastre étai...
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History of Chemistry - chemistry.
even better distillation apparatus than the Arabs had made and to condense the more volatile products of distillation. Among the important products obtained in thisway were alcohol and the mineral acids: nitric, aqua regia (a mixture of nitric and hydrochloric), sulfuric, and hydrochloric. Many new reactions could be carried outusing these powerful reagents. Word of the Chinese discovery of nitrates and the manufacture of gunpowder also came to the West through the Arabs. The Chinese atfirst use...
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COMPÉTENCE - SERVICES PUBLICS INDUSTRIELS ET COMMERCIAUX T. C. 22 janv. 1921, SOCIÉTÉ COMMERCIALE DE L'OUEST AFRICAIN, Rec. 91 (S. 1924.3.34, concl. Matter; D. 1921.3.1, concl. Matter)
expert contraitement aux art. 7 et 8 de l'ordonnance du I•• juin 1828, -c'est à bon droit qu'il a retenu la connaissance du litige; ... (Arrêté de conflit annulé). OBSERVA TI ONS 1. - Le commissaire du gouvernement Matter rapporta ainsi les faits qui furent à l'origine de cette affaire : « Le littoral de la Côte d'Ivoire est parsemé de lagunes qui rendent la circulation difficile; la colonie a eu l'heureuse idée de les couper de bacs. C'es...
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Ski nordisch: Medaillengewinner der Olympischen Winterspiele.
1924 Thorleif Haug, NOR Thoralf Strømstad, NOR Johan Gröttumsbraten, NOR 1928 Per-Erik Hedlund, SWE Gustaf Jonsson, SWE Volger Andersson, SWE 1932 Veli Saarinen, FIN Väinö Liikkanen, FIN Arne Rustadstuen, NOR 1936 Elis Wiklund, SWE Axel Wikström, SWE Nils-Joel Englund, SWE 1948 Nils Karlsson, SWE Harald Eriksson, SWE Benjamin Vanninen, FIN 1952 Veikko Hakulinen, FIN Eero Kolehmainen, FIN Magnar Estenstad, NOR 1956 Sixten Jernberg, SWE Veikko Hakulinen, FIN Fjodor Terentjew, URS 1960 Kalevi Hämäl...
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Cosmology - astronomy.
In 1917 American scientist Harlow Shapley measured the distance to several groups of stars known as globular clusters. He measured these distances by using amethod developed in 1912 by American astronomer Henrietta Leavitt. Leavitt’s method relates distance to variations in brightness of Cepheid variables, a class of starsthat vary periodically in brightness. Shapley’s distance measurements showed that the clusters were centered around a point far from the Sun. The arrangement of theclusters was...
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X-Ray Astronomy - astronomy.
Some neutron stars have weaker magnetic fields that allow incoming material to settle onto the entire surface of the neutron star. Eventually, so much material buildsup that the surface layer becomes dense enough to set off a vast thermonuclear explosion, called an outburst. The explosion heats gas to produce X rays. Such aneutron star—called an X-ray burster—can increase its X-ray production by a million times during an outburst. The X-ray glow fades over time, and the binary systementers a lon...
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Soil.
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INTRODUCTION
Soil, the loose material that covers the land surfaces of
an exchange between plants and the atmosphere, as oxygen diffuses into the soil and is used by roots for respiration. In turn, the resulting carbon dioxide diffusesthrough pore spaces and returns to the atmosphere. This exchange is most efficient in soils with a high degree of porosity. For farmers, gardeners, landscapers, andothers with a professional interest in soil health, the process of aeration—making holes in the soil surface to permit the exchange of air—is a crucial activity. Theburrowi...
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Supernova - astronomy.
The term hypernova has been proposed for an extremely massive core-collapse supernova—possibly more than 100 times the mass of the Sun. A hypernova is thought to form a black hole. Just before it explodes, a hypernova may release a huge burst of gamma rays in a jet from the rotating black hole at its center. These jets mayexplain the so-called long gamma-ray bursts detected by astronomers. According to some researchers, massive stars with over 40 solar masses may sometimescollapse directly int...
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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...
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Neutron
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INTRODUCTION
Neutron, electrically neutral elementary particle that is part of the nucleus of the atom.
Beta DecayBeta decay can occur in two ways. As shown on the left, a neutron turns into a proton by emitting an antineutrino and anegatively charged beta particle. As shown on the right, a proton turns into a neutron by emitting a neutrino and apositively charged beta particle. Positive beta particles are called positrons and negative beta particles are called electrons.After the decay, the nucleus of the atom contains either one less or one more proton. Beta decay changes an atom of oneelement i...
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Gardening - biology.
of synthetic and organic fertilizers, see Organic Farming.) Fertilizers usually are sold in packages, on which the percentage by weight of the macronutrients nitrogen (N), phosphorus (P), and potassium (K) are listed on thelabel—always in the order N-P-K. For example, a fertilizer that is labeled 10-5-3 is 10 percent nitrogen, 5 percent phosphorus, and 3 percent potassium. V PLANTING AND TRANSPLANTING Before planting seeds, gardeners prepare, or till, the soil using a variety of methods. Some...
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American Literature: Drama
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INTRODUCTION
American Literature: Drama, literature intended for performance, written by Americans in the English language.
American plays, while still a minority, began to appear in the theater repertory in the 19th century. Although American plays were still styled after British models, theirsubject matter came to be based on specifically American incidents or themes. In the United States as in Britain, many plays reflected the influence of romanticism , a European literary and artistic movement. Melodrama, with its outpourings of emotion, was the most prevalent dramatic form in the 19th century. Gothic melodramas...
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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...
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Roberto Matta 1911 Le Prophéteur
monde, ses différents moi, les autres, les luttes pour nager à travers toutes ces identités.» Matta est né à Santiago du Chili. Issu d'une famille hispano-franco-basque, il fait ses études secondaires chez les jésuites; plus tard, son sentiment sera d'avoir vécu dans une ambiance second Empire. A dix-huit ans, il s'inscrit en architecture à l'université catholique de Santiago; puis, passé à la section peinture, il réalise pour son diplôme cent quarant...
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Infrared Space Observatory - astronomy.
know how often these disks occur around stars to help them understand how common it is for planets to form. ISO found several previously unknown stars with disks.ISO also detected olivine, a silicate mineral found in Earth’s own rocky mantle, in the comet Hale-Bopp, which was visible from Earth in 1996 and 1997. The discovery ofolivine in the comet suggests that the comet and Earth have a similar origin. The satellite also detected the first evidence of water outside of the solar system inplanet...
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Et JE N'ai JAMAIS appris le polonais.
Je me suis détourné deMatt pourdemander àShlomo, Qu'est-ce qu'ilvient dedire ? Shlomo hochaitlatête fébrilement. Iladit, Ilme raconte l'histoire duprofesseur quiacaché Frydka ! Ilsait que Ciszko aété tué enmême tempsqueFrydka. ABolechow. C'estunehistoire qu'il aentendue aprèslaguerre. Ils ont denouveau parléenpolonais. Shlomodressait lessourcils. Iladit, Ilse souvient dunom du professeur dedessin quilesacachés ! Il s'est tupour ménager soneffet etila ajouté, Lenom duprofesseur étaitSzedlak ! She...
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Laser.
their atoms into laser light. Consequently, they are the most powerful continuous wave (CW) lasers—that is, lasers that emit light continuously rather than in pulses. C Liquid Lasers The most common liquid laser media are inorganic dyes contained in glass vessels. They are pumped by intense flash lamps in a pulse mode or by a separate gas laserin the continuous wave mode. Some dye lasers are tunable, meaning that the color of the laser light they emit can be adjusted with the help of a prism lo...
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Religion.
By the end of the 19th century, scholars were making religion an object of systematic inquiry. Müller’s comparative approach was adopted in many European andJapanese universities, and as a result the common features of world religions (such as gods, prayer, priesthood, and creation myths) were the subjects of sustainedscholarly investigation. In addition, field anthropologists had begun to compile firsthand accounts of the religions of peoples who previously had been dismissed assavages. The stu...
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Physical Chemistry - chemistry.
by the system in the form of the flow of electrical currents, formation of surfaces and changes in surface tension, changes in volume or pressure, and formation ordisappearance of chemical species. B Chemical Kinetics This field studies the rates of chemical processes as a function of the concentration of the reacting species, of the products of the reaction, of catalysts and inhibitors, ofvarious solvent media, of temperature, and of all other variables that can affect the reaction rate. It is...
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Redshift - astronomy.
Astronomers can also use redshift to identify the oldest and most distant objects in the observable universe. Astronomers believe that quasars are the most distantobjects in the universe, because they have some of the largest redshifts. Quasars are objects in space that strongly emit radio waves. Astronomers originally namedthese objects quasars, which stands for quas i-stell ar (or starlike) radio source, because they appear as points of light, like stars, in photographs of the sky. When astro...
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Galaxy - astronomy.
Astronomers have obtained images of young galaxies using the Keck Telescope in Hawaii and the Hubble Space Telescope, which resides in an orbit high above Earth’satmosphere and thus avoids atmospheric interference. Photos from the HST show galaxies that are as far as 13 billion light-years away from Earth, which means theyformed soon after the universe formed about 13.7 billion years ago. The galaxies appear to be spherical in shape, and may be early precursors of elliptical and spiralgalaxies....
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Ski alpin: Medaillengewinner der Weltmeisterschaften.
2001 Mario Matt, AUT Benjamin Raich, AUT Mitja Kunc, SLO 2003 Ivica Kostelic, CRO Silvan Zurbriggen, SUI Giorgio Rocca, ITA 2005 Benjamin Raich, AUT Rainer Schönfelder, AUT Giorgio Rocca, ITA 2007 Mario Matt, AUT Manfred Mölgg, ITA Jean-Baptiste Grange, FRA * von 1948 bis 1980 wurden die Ergebnisse der Olympischen Winterspiele zugleich als Weltmeisterschaftsresultategewertet . Riesenslalom MännerJAHR GOLD SILBER BRONZE 1950 Zeno Colò, ITA Fernand Grosjean,SUI James Couttet, FRA 1952* Stein Eri...
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Gravitation
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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...