March 2, 2017 at 5:25 pm

Carl Sagan Explains How Eratosthenes Knew the Earth Was Curved Over 2,200 Years Ago

by twistedsifter

In this excerpt from episode 1 of Carl Sagan’s ‘Cosmos’, he explains how the Greek scholar, Eratosthenes, knew the Earth was curved over 2,200 years ago.

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Tags: · carl sagan, explainer, history, mathematics, science, shadows, the sun, top

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Carl Sagan Explains How Eratosthenes Knew the Earth Was Curved Over 2,200 Years Ago