Columbus and the Flat Earth Myth

CAN we all agree to bury that resilient myth that it was Columbus' journey to the New World that proved that the world was round? In the excellent November 2006 issue of the Kappan, which dealt with education about Native Americans, one of the guest editors uses the story to argue that study of American history must include the history of those whose lineage can be traced back hundreds of years before European seafarers began to wonder if ships might not fall off the edge of the world. Similarly, in The World Is Flat, Thomas Friedman repeats the error when he writes, Columbus reported to his king and queen that the world was round, and he went down in history as the man who first made this discovery.

Well, no, he didn't. Thomas Kuhn in The Copernican Revolution showed clearly in 1957 that the idea of a flat Earth was rejected very early in recorded history. There are references to the measurement of the Earth's circumference that appear in the writings of Aristotle (384-322 BCE), but the first complete record of this measurement comes from Eratosthenes (276-194 BCE), the librarian of Alexandria, who arrived at a figure that was off by only about 5% from present-day measurements.

The belief in the sphericity of the Earth, even back in those early days, was based on careful observations and solid reasoning. The fact that the hulls of ships moving away disappeared before their masts; the fact that, if you were on high ground, you could see more of the ship than when you were at sea level; the circular edge of the shadow of the Earth on the Moon during lunar eclipses--all were convincing arguments against a flat Earth, and educated people as early as Classical times accepted them as conclusive. Even the idea of sailing westward from Europe to reach India was originally proposed by geographer Strabo, who was born around 63 BCE.

Aristarchus (310-230 BCE) and others in the third century BCE even made sophisticated measurements of the sizes of the Moon and the Sun and the various distances between them. And these things were not secrets. All were widely known among educated people.

So how did this notion arise that Europeans of the late 15th century were ignorant of one of the basic and most certain pieces of knowledge that had been deduced almost two thousand years earlier? Understanding that puzzle provides interesting insights into how myths can grab the imagination of people and retain their power in the face of overwhelming evidence to the contrary. It is true that faced strenuous objections from the Spanish court to his proposed venture, but this opposition had nothing to do with fears that his ships would fall off the edge of the Earth, since the educated people of Spain knew very well that the Earth was a sphere.

Rather, they suspected that Columbus, showing a level of political cunning that would have impressed today's strategists, had cherry picked and fudged the available data to suit his purposes and had come up with a dubious calculation that projected the length of his trip to be only 20% of the actual distance. Thus he made his trip appear more viable than it was. His opponents argued (correctly) that his numbers were wrong and that he and his crew would not be able to carry enough provisions to reach India.

And they did not want to gamble their ships and crew on what seemed like a reckless venture. Why would advocate such a foolish thing, since he was risking his own life in the bargain? The answer is not clear.

Perhaps, being the adventurer he was, he was also a gambler who had set his mind on making this voyage and then had fallen prey to that all-too-human trait of trusting only the data that justified his desired course of action and rejecting anything that argued otherwise. Whatever the reason, managed to finally persuade the Spanish government to underwrite his voyage, which would have certainly ended in disaster but for the existence of America. …