The Song of Urania

We turn back the clock and see how a variety of Greek astronomers over the centuries contributed to the Greek calendar, and how Greek politicians ignored their developments. Then we see how the discovery that the seasons are not of equal lengths posed a problem for Eudoxus's theory of planetary motion.

In working on the problem of doubling the cube, Plato's friend Archytas devised an ingenious solution that involved a three dimensional curve determined by the intersection of a torus with a cylinder. Archytas's student Eudoxus then seems to have been inspired by this solution to develop the first serious model of planetary motions in ancient Greece, his theory of homocentric spheres.

Before leaving the world of the Pre-Socratics, we look briefly at the astronomy of Oenopides, which had a more observational character than many of his contemporaries. Then we turn to Plato, the first of the great astronomers in the Socratic tradition, whose astronomy synthesized the best ideas of his predecessors.

Two philosophers, Leucippus and Democritus, attempted to synthesize the monist theories of the earlier natural philosophers with the pluralist theories of Empedocles and Anaxagoras. To do this, they proposed a revolutionary idea — that all matter is made of atoms.

As we transition from the Archaic Period of Greece to the Classical Period, two philosophers, Empedocles and Anaxagoras, rebel against the prevailing dogma of monism and present a new idea — that matter consists of mixtures of multiple fundamental elements.Thanks to William Little of Ohio State for help with the Latin to get the opposite of "E pluribus unum" for the title.If you would like to register for the Stellar Spectacles symposium that I mentioned at the beginning of the episode, go to www.asxsociety.com

After the Median invasion, the Ionian philosopher Xenophanes, a student of the Anaximander, was forced to flee to Elea in Magna Graecia and brought the philosophy of the Ionians to the Eleans. His student, Parmenides, then founded the Eleatic School, which was skeptical of the senses, and argued that despite its appearance to the contrary, the Earth was round. Parmenides's student, Zeno, in turn developed his famous paradoxes to prove his teacher's assertion that motion was an illusion.

We turn to the enigmatic, charismatic philosopher Pythagoras and the following that he inspired. Though Pythagoras is today associated with the Pythagorean theorem, he developed a school whose secrets were jealously guarded. The Pythagoreans studied astronomy, mathematics, and music, but also developed a unique philosophy centering around numbers that heavily influenced Plato.

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?

Explore the life and work of Thales, the first Greek astronomer. Dive into the evolution of writing systems, lost texts, and Thales' influence in ancient Greece. Discover scatological graffiti in latrines, hygiene practices, biblical references, and Thales' potential eclipse prediction.

We outline the early development of Greek civilization after the Late Bronze Age Collapse and how the unique geography of Greece influenced its culture, and ultimately, its astronomy. Then we explore the cosmology, cosmogony, and astronomy of the earliest Greeks based on the works of Homer and Hesiod.