Hipparchus (astronomer)

:For other uses of Hipparchus, see Hipparchus (disambiguation).

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Hipparchus (Greek Ἳ???????) (ca. 190 BC – ca. 120 BC) was a Greek astronomer, geographer, and mathematician.

Related Topics:
Greek - 190 BC - 120 BC - Greek - Astronomer - Geographer - Mathematician

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Hipparchus was born in Nicaea (now Iznik, Turkey) and probably died on the island of Rhodes. He is known to have been active at least from 147 BC to 127 BC. Hipparchus is considered the greatest astronomical observer, and by some the greatest astronomer of antiquity. He was the first Greek to develop quantitative and accurate models for the motion of the Sun and Moon. For this he made use of the observations and knowledge accumulated over centuries by the Chaldeans from Babylonia. He was also the first to compile a trigonometric table, which allowed him to solve any triangle. With his solar and lunar theories and his numerical trigonometry, he was probably the first to develop a reliable method to predict solar eclipses. His other achievements include the discovery of precession, the compilation of the first star catalogue, and probably the invention of the astrolabe. Claudius Ptolemaeus, three centuries later depended much on Hipparchus. However, his synthesis of astronomy superseded Hipparchus's work: although Hipparchus wrote at least fourteen books, only his commentary on the popular astronomical poem by Aratus has been preserved by later copyists. As a consequence, we know comparatively little about Hipparchus.

Related Topics:
Nicaea - Rhodes - 147 BC - 127 BC - Antiquity - Sun - Moon - Chaldeans - Babylonia - Trigonometric - Solar eclipse - Precession - Star catalogue - Astrolabe - Claudius Ptolemaeus - Aratus

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