Miletus became a wealthy Greek city during the Archaic Period and developed a thriving intellectual culture which included many of the most important pre-Socratic astronomers. We looked at Thales in the last episode and now we try to understand the astronomy of other members of the Ionian School — Anaximander, Anaximenes, and Heraclitus. What did their astronomy have in common with each other and what are the connections between their ideas and the ideas of modern physics?