Ptolemy was an astronomer, mathematician, and geographer who lived during the 2nd century CE. He is known for his geocentric (Earth-centred) model of the universe.
Ptolemy was one of Alexander's most trusted companions and military officers. After the death of Alexander in 323 BC, Ptolemy retrieved his body as it was en route to be buried in Macedon, placing it in Memphis instead, where it was later moved to Alexandria in a new tomb.
Ptolemy was a keen astronomer, although he was reliant on the naked eye since the telescope was not invented until the early 17th century. What Ptolemy did have access to were masses of astronomical observations taken by ancient Babylonian scientists from the 8th to the 3rd centuries BCE.
Claudius Ptolemy wrote the Almagest, the work that defined astronomy for over 1,000 years. The Almagest included a catalogue of over a thousand stars, recording their positions, constellations, and relative brightnesses; and a mathematical model predicting the movements of the planets.
Ptolemy can be described as a polymath because his studies ranged across an astonishing array of disciplines, from astronomy and geography, to mathematics, philosophy, literature and poetry. The best indications place Ptolemy’s birth at about 90 A.D. in Alexandria, Egypt.
Claudius Ptolemy (c. 100 – c. 170 AD) was a towering figure in the ancient world, renowned for his extensive contributions to various fields of science. His life and works left an indelible mark on mathematics, astronomy, astrology, geography, and music theory.
Ptolemy, or in Latin Claudius Ptolemaeus (ca. 90 – ca. 168 C.E.), was a mathematician, philosopher, geographer, map maker, astronomer, theologian, and astrologer who lived in Alexandria, Egypt.