Ptolemy

Ptolemy was a Greek astronomer and geographer working in Alexandria in the second century, about whom nothing personal is known. The Almagest, in thirteen books, gathered the astronomy of the Greeks into a mathematical system in which the earth stands still at the centre and the sun, moon and planets circle it on epicycles and eccentrics that reproduce their observed motions, and it was the astronomy of the world for fourteen centuries, until Copernicus. His Geography mapped the known world, and his Tetrabiblos the astrology. St. John’s reads the Almagest in the sophomore mathematics tutorial, before Copernicus and Kepler, to see what they overturned.