Ptolemy: (87 -150 AD)
He was an astronomer, mathematician and geographer. He codified the Greek geocentric view of the universe, and rationalized the apparent motions of the planets as they were known in his time.
Ptolemy synthesized and extended Hipparchus's system of epicycles and eccentric circles to explain his geocentric theory of the solar system. Ptolemy's system involved at least 80 epicycles to explain the motions of the Sun, the Moon, and the five planets known in his time. He believed the planets and sun to orbit the Earth in the order Mercury, Venus, Sun, Mars, Jupiter, Saturn . This system became known as the Ptolemaic system. It predicts the positions of the planets accurately enough for naked-eye observations This is described in the book Mathematical Syntaxis (widely called the Almagest), a thirteen book mathematical treatment of the phenomena of astronomy. It contains a myriad of information ranging from earth conceptions to sun, moon, and star movement as well as eclipses and a breakdown on the length of months. The Almagest also included a star catalog containing 48 constellations, using the names we still use today.
Sources: http://obs.nineplanets.org/psc/theman.html
He was an astronomer, mathematician and geographer. He codified the Greek geocentric view of the universe, and rationalized the apparent motions of the planets as they were known in his time.
Ptolemy synthesized and extended Hipparchus's system of epicycles and eccentric circles to explain his geocentric theory of the solar system. Ptolemy's system involved at least 80 epicycles to explain the motions of the Sun, the Moon, and the five planets known in his time. He believed the planets and sun to orbit the Earth in the order Mercury, Venus, Sun, Mars, Jupiter, Saturn . This system became known as the Ptolemaic system. It predicts the positions of the planets accurately enough for naked-eye observations This is described in the book Mathematical Syntaxis (widely called the Almagest), a thirteen book mathematical treatment of the phenomena of astronomy. It contains a myriad of information ranging from earth conceptions to sun, moon, and star movement as well as eclipses and a breakdown on the length of months. The Almagest also included a star catalog containing 48 constellations, using the names we still use today.
Sources: http://obs.nineplanets.org/psc/theman.html
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