Origins of the Spherical Earth in Ancient Greek Cosmology

Diogenes Laertius ascribes the first concept of spherical Earth to both Pythagoras and Parmenides. Indeed, a major shift in cosmologies—emergence of the spherical conception of the Earth and the surrounding heaven—took place between the sixth and fifth centuries BCE. Given the poor state of preservation of early Pythagorean tradition, it is argued that primacy in formulating the notion of spherical Earth should be ascribed to Parmenides.