Thales of Miletus: produces an accurate theory of the solar eclipse
Anaxmiander: Argued that life evolved from beginning in the sea and that humankind evolved from a more primitive species; laid groundwork for evolutionary theory
Pythagoras: Argues for a spherical earth around which five planet revolved. Also laid down the Pythagoran Theorem, in which the square of the hypotenuse of a right triangle equals the sum of the square of the two sides.
Leucippus: Theorized that all matter is composed of atoms
Anaxagoras: Postulates that the sun is a large, glowing rock and explained solar eclipses