“People used to believe the Earth was flat.”

The notion that people in the Middle Ages widely believed the Earth was flat is a pervasive historical misconception. In truth, educated individuals in ancient Greece, and throughout the Middle Ages, generally understood and accepted that the Earth was spherical. This knowledge was established by Greek thinkers as early as the 5th century BCE and never truly faded among scholars.

This myth largely gained traction in the 19th century, propagated by writers such as Washington Irving, John William Draper, and Andrew Dickson White. These authors often presented earlier eras, particularly the Middle Ages, as ignorant and superstitious, contrasting them with the perceived enlightenment of their own time. This narrative served to highlight an ideological conflict between religion and science, with the "flat Earth" belief being falsely attributed to religious dogma.

Historical evidence overwhelmingly supports the understanding of a spherical Earth. Ancient Greek philosophers like Pythagoras and Aristotle provided arguments and observations for its roundness. Aristotle, for instance, noted that the Earth's shadow on the moon during a lunar eclipse was always circular. Furthermore, Eratosthenes accurately calculated the Earth's circumference in the 3rd century BCE, demonstrating a sophisticated understanding of its spherical shape. Seafarers also observed that the tops of approaching ships were visible before their hulls, a phenomenon only possible on a curved surface.

The myth persists today due to several factors, including its reinforcement in popular culture and simplified historical accounts. It often serves as a convenient, albeit inaccurate, symbol for past ignorance or a perceived conflict between scientific progress and earlier belief systems. Despite overwhelming evidence to the contrary, this engaging but incorrect narrative continues to be a common misconception.