Philolaus (c. 480 BC) - a follower of Pythagoras, he believed that the Earth, Moon, and planets traveled in spheres which circled around a central fire that was partially visible in the Sun. Plato (427-347 BC) - Greek philosopher whose real name was Aristocles. He believed the Sun, Moon, planets, and stars moved around the earth in perfect spheres, and the Moon shown by reflected sunlight. Ptolemy, Cladius (c.120- c.151 A.D.) - Roman astronomer whose work influenced astronomy until the end of the Dark Ages. Proponent of the geocentric model of universe (the Sun, Moon, and planets orbit the earth), he wrote the Megale Syntaxix, better known as the Almagest in which he describes the details of the geocentric theory. Included in the work are detailed charts for predicted future locations of the objects in the solar system. Pythagoras (580- c.500 BC) - Greek mathematician who proposed that the Earth was a globe surrounded by 8 concentric spheres which had the Moon, Sun, and known planets attached to them.