Ancient Greek science began around 300 BC and was focused on organizing the world and gaining knowledge in areas like astronomy, biology, physics and mathematics. Some of the major figures who studied these areas were Thales, Pythagoras, Anaxagoras, Empedocles, Aristotle, Archimedes and Democritus. Archimedes in particular made important contributions to the fields of mathematics and engineering through his principles of buoyancy and inventions.