What did Ptolemy do in astronomy? Ptolemy made contributions to astronomy, mathematics, geography, musical theory, and optics. He compiled a star catalog and the earliest surviving table of a trigonometric function and established mathematically that an object and its mirror image must make equal angles to a mirror.
What is Ptolemy most famous for? Key facts. Claudius Ptolemy was a 2nd century Greek mathematician, astronomer and geographer famous for his controversial geocentric theory of the universe, which would form the basis of our understanding of the motions of stars and planets for over than a thousand years.
What did Ptolemy believe in astronomy? Based on observations he made with his naked eye, Ptolemy saw the Universe as a set of nested, transparent spheres, with Earth in the center. He posited that the Moon, Mercury, Venus, and the Sun all revolved around Earth.
What is an interesting fact about Ptolemy? Ptolemy was a great mathematician, astronomer, and geographer. While his most famous work is in the field of astronomy, he was more successful as a geographer. His world map was the most accurate point of reference for many years.