Since today is Columbus Day, I thought I would discuss a myth commonly associated with the man. I learned it in school, as did many others. It’s the myth that people in Columbus’s day thought the earth was flat. Highlights of American History Before 1850, for example, tells students about a conversation that supposedly took place between Christopher Columbus and Queen Isabella:1
“Your Highness,” said Columbus, “instead of going east across the land to reach India, your traders can sail west across the ocean.” “What? Are you mad?” asked Queen Isabella. “If they sail too far west they will fall off the edge of the earth!”
A more recent book puts it this way:2
Only 500 years ago, sailors aboard the Santa Maria begged Columbus to turn back lest they sail off the Earth’s “edge.”
There is a big problem with such pronouncements: no historical evidence exists to back up the idea that most people (even uneducated people) in Columbus’s day believed the earth was flat. In addition, there is a wealth of evidence that indicates no one took such an idea seriously.
We know, for example, that philosophers understood the spherical shape of the earth long before Christ was born. It was discussed by philosophers like Pythagoras in the fifth century BC3 and became widely accepted when it was championed by Aristotle (384–322 BC). He saw that the stars were different in one part of the world than the other. This indicated to him that the earth must be a sphere.4 The spherical shape of the earth was so widely accepted among philosophers that Eratosthenes (c.276–c.195 BC) used the change in a staff’s shadow resulting from a 500-mile trip to measure the circumference of the earth. He was correct to within less than 2% of today’s accepted value.5