The Greek mathematician and astronomer Eratosthenes took the notion a step ... cosmologist and astrophysicist Carl Sagan, the idea of the Earth being in the shape of a circle can be easily proven ...

Flat Earth Debunked 2,000 Years Ago? Carl Sagan Explains Eratosthenes Posted: April 24, 2025 | Last updated: April 24, 2025 I’ve had a surprising number of comments telling me the Earth is flat. 50.

In 1980, Carl Sagan opened his series Cosmos with these ... Sagan choose for his subject the ancient Greek mathematician Eratosthenes, who correctly calculated the curvature of the Earth by ...

Eratosthenes knew that the distance between ... If you fancy a more visually compelling explanation, you can check the great Carl Sagan talking about it in the clip below: ...

Carl Sagan explained how Eratosthenes, a scholar and librarian living in ancient Egypt, figured out the curvature of the Earth using only, as Sagan put it, "sticks, eyes, feet and brain, plus a zest ...

About 2,250 years ago, there was a man called Eratosthenes. He was one of those ... Watch the short clip below of the great Carl Sagan to see how it was done. I've set it to play from the ...

As explained by Carl Sagan in the above video, Eratosthenes planted a stick in the ground in Syene, a city south of Alexandria, and another in Alexandria. The distance between the two sticks was ...