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

Carl Sagan

This video is from the first episode of Carl Sagan’s brilliant ‘Cosmos’, he explains how the Greek scholar, Eratosthenes, knew the Earth was curved over 2,200 years ago. This is one mind-bending explanation. Check out the video below:

Leave a Reply