Anaximander was a pupil of Thales and active in Miletus in the first half of the 6th century BC. For the vast scope and variety of his research, he is considered the inaugurator of a tradition of learned men to whom art paid homage via portraiture. The author of a revolutionary image of the universe, he was the first to suggest the Earth occupied the centre of the cosmos without requiring any support. Equidistant from the points of the celestial sphere, it was the barycentre of the system. Anaximander is also attributed with the first geographical portrayal of the known world and the invention of the sundial, making space and time describable and measurable entities.