| Considered the first true mathematician, Pythagoras in the 6th century bc emphasized the study of mathematics as a means to understanding all relationships in the natural world. His followers, known as Pythagoreans, were the first to teach that the Earth is a sphere revolving around the Sun. This detail showing Pythagoras surrounded by his disciples comes from a fresco known as the School of Athens (1510-1511), by Italian Renaissance painter Raphael. |