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.
Channels: AMAZING, INFORMATIVE
Tags: · carl sagan, explainer, history, mathematics, science, shadows, the sun, top