Ptolemy

Franklin Library Claudius Ptolemy books

Works of Nicolaus Copernicus, Johannes Kepler and Ptolemy - Great Books of the Western World - 1985

Ptolemy biography

Ptolemy, known in full as Claudius Ptolemaeus, was a prominent ancient Greek mathematician, astronomer, geographer, and astrologer who lived in Alexandria, Egypt, during the 2nd century AD. His exact dates of birth and death are uncertain, but he is believed to have lived between approximately 100 AD and 170 AD.

Ptolemy's most enduring contributions to human knowledge came through his works on astronomy and geography, which profoundly influenced scientific thought for centuries to come. His masterpiece, The Almagest, is a comprehensive treatise on astronomy that synthesized the astronomical knowledge of his time and presented it in a systematic and organized manner. In The Almagest, Ptolemy presented a geocentric model of the universe, in which Earth was believed to be at the center, with the Sun, Moon, planets, and stars orbiting around it in concentric spheres. Despite its eventual supersession by heliocentric models, Ptolemy's geocentric system remained the prevailing cosmological model in Western civilization for over a millennium.

In addition to his astronomical work, Ptolemy made significant contributions to the field of geography with his work "Geography." This influential text provided a comprehensive overview of the known world at the time, describing its various regions, cities, and geographical features. Ptolemy also developed a system of latitude and longitude coordinates, which would become fundamental to cartography and navigation in subsequent centuries.

Ptolemy's influence extended beyond the realms of science and geography; he was also a notable figure in the field of astrology. His work Tetrabiblos explored the principles of astrology and became one of the foundational texts of Western astrological tradition. Despite the profound impact of his works, much of Ptolemy's life remains shrouded in mystery. Little is known about his personal background, including his education and upbringing. Nevertheless, his contributions to astronomy, geography, and astrology have earned him a lasting legacy as one of the most influential figures in the history of science and scholarship.