Voyages of Christopher Columbus

Diameter of Earth and travel distance estimates

A spherical Earth had been the general opinion of Ancient Greek science, and this view continued through the Middle Ages (for example, Bede mentions it in The Reckoning of Time). In factEratosthenes had measured the diameter of the Earth with good precision in the 2nd century BC.^[10]Where Columbus did differ from the generally accepted view of his time was in his (very incorrect) arguments that assumed a significantly smaller diameter for the Earth, claiming that Asia could be easily reached by sailing west across the Atlantic. Most scholars accepted Ptolemy's correct assessment that the terrestrial landmass (for Europeans of the time, comprising Eurasia and Africa) occupied 180 degrees of the terrestrial sphere, and dismissed Columbus' claim that the Earth was much smaller, and that Asia was only a few thousand nautical miles to the west of Europe. Columbus' error was attributed to his insufficient experience in navigation at sea.