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Prolemy proposes a geocentric universe in which the sun, moon and other planets revolve around the Earth in a complicated system of circular orbits
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Jan 1, 1543
Copemicus introduces a heliocentric system with the planets in circular orbits
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Italien scientist Giordano Bruno claims that neither Earth nor the sun is the center of the universe. Instead, he suggests that the sun is simply one of infinitely many stars and that there might be countless planets like Earth
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Tycho Brahe proposes a system that combines aspects of both the Copernican and Ptolemaic models, with the sun revolving around the Earth and the other planets orbiting the sun
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Johannes Kepler posits three laws of planetary motion
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Galileo Galilei builds his first telescope
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Isaac Newton publishes Mathematical Principles of Natural Philosophy
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Friedrich Bessel, a German mathematician and astronmer, measures stellar parallax
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Henrietta Swan Leavitt publishes her discovery of being able to calculate the distance of various Cepheids from Earth
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Albert Einstein presents a trailblazing model of gravitation
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Edwin Hubble discovers the Andromeda Galaxy is 900,000 light-years from Earth
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George Lemaitre presents an early version of the big-bang theory based on the theory of relativity
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Edwin Hubble discovers that the speed at which galaxies are moving away from us is proportional to their distance from the Earth
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Fritz Zwicky discovers the first indications that the space between galaxies might contain an invisible form of matter
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George Garnow publishes The Origin of Chemical Elements
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Engilsh astronomer Fred Hoyle derides Gamow's theory, calling it the big bang, while revising and presenting the steady-state theory that posits the constant creation of new atoms in empty space
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American astronomers Amo Penzias and Rovert Wilson stumble upon cosmic microwave backround radiation while testing a highly sensitive antenna
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American astronomers Vera Rubin and Kent Ford show that stars on the outskirts of a spiral galaxy move much faster than expected
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The COBE satellite shows, as predicted, that the cosmic microwave background is the remnant heat of the early universe
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Research teams from the US and Australia independently show that the universe is expanding at a constantly increasing rate
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450 BCE Anaxagoras proposes an infinitely large universe
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260 BCE Aristarchus of Samos envisions a heliocentric universe were the sun is the center, but his theory gets little support
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450 BCE Anaxagoras proposes an infinitely large universe, composed of atoms and empty space
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Aristarchus of Samos envisions a heliocentric universe where the sun is the center, but his theory gets little support
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450 BCE Anaxagoras proposes an infinitely large universe coposed of atoms and empty space
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260 BCE Aristarchus of Samos envisions a heliocentric universe where the sun is the center, but his theory gets little support
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260 BCE Aristarchus of Samos envisions a heliocentric universe where the sun is the center, but his theory gets little support
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450 BCE Anaxagoras proposes an infinitely large universe composed of atoms and empty space
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The Wilkinson Microwave Anisotropy Probe precisely measures the very small temperature differences in the afterglow of the big bang, which suggest that matter was not evenly distributed in the early universe but instead had "lumps" that became the seeds o
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Maps of the universe's macrostructure reveal that galaxies are not distributed uniformly throughout the universe
