6th-century BC astronomers

ancient Greek philosopher and mathematician

Anaximander ( ; Anaximandros; ) was a pre-Socratic Greek philosopher who lived in Miletus, a city of Ionia (in modern-day Turkey). He belonged to the Milesian school and learned the teachings of his master Thales. He succeeded Thales and became the second master of that school, where he counted Anaximenes and, arguably, Pythagoras amongst his pupils.

Nabu-ri-man-nu (also spelled Nabu-rimanni; Greek sources called him Ναβουριανός, Nabourianos, Latin Naburianus) (fl. c. 6th – 3rd century BC) was a Chaldean astronomer and mathematician.