https://en.wikipedia.org/wiki/Spherical_EarthPosted by Wikipedia
The concept of a spherical Earth dates back to around the 6th century BC, when it was mentioned in ancient Greek philosophy,[1] but remained a matter of philosophical speculation until the 3rd century BC, when Hellenistic astronomy established the spherical shape of the earth as a physical given. The paradigm was gradually adopted throughout the Old World during Late Antiquity and the Middle Ages.