Ptolemy

Ptolemy was a Greco-Roman mathematician, astronomer, geographer and astrologer. He lived in Alexandria in the Roman province of Egypt, under the rule of the Roman Empire, around AD 100 to c. 170. Ptolemy was the author of several scientific treatises, three of which were of great importance to later Byzantine, Islamic, and Western European science. The first is the astronomical treatise now known as the Almagest, although it was originally entitled the Mathematical Treatise and later known as The Great Treatise.

Life

Ptolemy's life is mostly known from his works, which suggest that he was born in Ptolemais Hermiou in the Thebaid. He lived in Alexandria, the cultural capital of the Hellenistic world, from around AD 127 to 148, during the reigns of the Roman Emperors Hadrian and Antoninus Pius.

Works

Ptolemy's most famous work is the Almagest, a comprehensive treatise on astronomy and geography. It includes a star catalogue and a detailed explanation of Ptolemy's geocentric model of the universe, which was widely accepted until the publication of Copernicus' De revolutionibus orbium coelestium in 1543.

Ptolemy also wrote the Tetrabiblos, a foundational work of astrology, and the Geography, which provided a detailed description of the known world.

Legacy

Ptolemy's works were highly influential in the Middle Ages and the Renaissance. His geocentric model of the universe was the accepted cosmological model in the Western world until the 16th century. His works on geography were used as a primary source by many mapmakers during the Renaissance.

See also

• History of astronomy
• History of geography
• History of mathematics
• History of astrology

References

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External links

• Ptolemy at Encyclopædia Britannica
• Ptolemy at Stanford Encyclopedia of Philosophy

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  Ptolemy with armillary sphere model
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  Ptolemy with Urania
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  Ptolemy
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  Ptolemy's World Map
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  Ptolemy's Quadripartitum
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