The major sciences of the Hellenistic Age were astronomy, mathematics, geography, medicine, and physics. The most renowned of the early Hellenistic astronomers was Aristarchus of Samos (310-230 B.C.), sometimes called the “Hellenistic Copernicus.” His primary accomplishment was his deduction that the Earth and the other planets revolve around the Sun. This view was not accepted by his successors because it conflicted with the teachings of Aristotle and also with the Greek conviction that humanity, and therefore the Earth, must be at the centre of the universe. Later, in the second century A.D., Aristarchus’s fame was overshadowed by that of Ptolemy of Alexandria. Although Ptolemy made few original discoveries, he systematized the works of others. His principal writing, The Almagest, based on the view that all heavenly bodies revolve around the Earth, was handed down to medieval Europe as the classic summary of ancient astronomy.