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Period: 276 BCE to 194 BCE
Eratosthenes
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63 BCE
Eratosthenes acheivements
According to the Suda, his corads nicknamed him Beta, the second letter of the Greek alphabet, because he was the second best in the world in almost any field. He was the first person to calculate the circumference of the Earth, with accuracy, and he invented a system of latitude and longitude. -
Period: 100 to 170
Claudius Ptolemy
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140
Ptolemy acheivements
He was an astronomer, mathematician, and geographer. He described in his writing the Greek geocentric view of the universe. Earlier Greek philosophers changed the old assumption of a flat Earth. They substituted a spherical Earth surrounded by a Celestial sphere. Ptolemy built these two spheres into a system of nested spheres recreating a solsr system. He also thought out and described the apparent motions of the planets as they were known in his time. -
Period: Feb 19, 1473 to May 24, 1543
Nicolaus Copernicus
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1543
Copernicus achievement
Copernicus' main idea was that our world is heliocentric. His theory was that the sun is in the middle of the solar system, and the planets go around it. This was published in his book, "De revolutionibus orbium coelestium" on the Revolutions of stars. -
Period: Dec 13, 1546 to
Tycho Brahe
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Period: Dec 27, 1571 to
Johannes Kepler
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1572
Brahe acheivement
Brahe constructed a small observatory on property owned by a relative. Here occurred the third and most important astronomical event in Tycho’s life. He saw a “new star,” brighter than Venus and where no star was supposed to be, in the constellation Cassiopeia. -
Kepler acheivements
Kepler used three laws to say what form the path has and how fast the planet moves. Kepler's first law says that the form of the path is an ellipse, an oval or flattened circle that has two centers. Kepler's second law says how fast the planet moves around the ellipse. Kepler's third law says how fast different planets move. -
Period: to
Sir Isaac Newton
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Newton acheivements
He is famous for his work on the laws of motion, optics, gravity, and calculus. In 1687, Newton published a book called the Philosophiæ Naturalis Principia Mathematica in which he presents his theory of universal gravitation and three laws of motion. -
Period: to
Albert Einstein
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Einstein acheivement
He worked on theoretical physics. He developed the "theory of relativity". He received the Nobel Prize in Physics in 1921 for theoretical physics. His famous equation is E=mc^2 (E = energy, m = mass, c = speed of light).