On Philolaus' astronomy (Q2339270)

Building on \textit{Carl A. Huffman}'s understanding of Philolaus of Croton's cosmology as ``the most impressive example of Presocratic speculative astronomy'' [Philolaus of Croton: Pythagorean and Presocratic. New York: Cambridge University Press (1993), p. 241], the author presents a possible model for Philolaus's cosmological system, with a central fire in the center, the counter-Earth, the Earth, the Moon, the Sun, the five planets on circular orbits around the central fire, and a circle of ``fixed'' stars, which is motionless. The central question that the author aims to explain is the need for a counter-Earth, which is located on an orbit closer to the central fire than the Earth, and thus invisible from positions on Earth ``facing outward''. Its function is to explain the occurrence (otherwise unexplainable) of crepuscular lunar eclipses (occurring at dawn or dusk).