The myth that people believed the earth was flat until Columbus proved them wrong is an example of major, motivated, misdirection. As early as the sixth century BC, Pythagoras – and later Aristotle and Euclid – wrote about the earth as a sphere. Eratosthenes at the beginning of the second century BC devised a method for calculating, fairly accurately, the circumference of the spherical earth.14 When Ptolemy wrote his Geography in the second century AD he considered the idea of a round planet as taken for granted.
