AFTER THE GREEK PHILOSOPHERS PYTHAGORAS, IN THE 6TH CENTURY BC, AND PARMENIDES, IN THE 5TH, RECOGNIZED THAT THE EARTH IS SPHERICAL, THE SPHERICAL VIEW SPREAD RAPIDLY IN THE GREEK WORLD. AROUND 330 BC, ARISTOTLE MAINTAINED ON THE BASIS OF PHYSICAL THEORY AND OBSERVATIONAL EVIDENCE THAT THE EARTH WAS SPHERICAL. WHEN WAS THE WORLD DISCOVERED TO BE ROUND?