FactSentinel

The idea that ancient sailors feared sailing off the edge of a flat Earth is a persistent myth with little basis in historical fact. Educated societies across the ancient world, including the Greeks, understood that the Earth was spherical as early as the 6th century BCE. Philosophers and astronomers such as Pythagoras, Aristotle, and later Eratosthenes not only argued for a round Earth but provided observational evidence for it, such as the curved shadow the Earth casts on the moon during lunar eclipses and the way ships disappear hull-first over the horizon. Eratosthenes even calculated the Earth's circumference with remarkable accuracy around 240 BCE using simple geometry and shadow measurements.

By the time of the Roman Empire and throughout the Middle Ages, the spherical Earth model was widely accepted among scholars, navigators, and the educated elite. Sailors and explorers of antiquity, including the Phoenicians and later medieval navigators, relied on the predictable curvature of the Earth for navigation techniques like celestial observation. Christopher Columbus's contemporaries, for example, did not doubt the Earth's roundness; their skepticism about his voyage centered on his underestimation of the planet's actual size, not fears of falling off an edge.

This myth largely originated in the 19th century, popularized by writers like Washington Irving, who dramatized the Columbus story to suggest ignorant medieval attitudes. Historians now recognize this as a fabrication that misrepresents both ancient and medieval scientific understanding, conflating limited folk beliefs with the sophisticated astronomical knowledge that actually guided navigation and exploration for millennia.