Carl Sagan: Eratosthenes Figured out the Curvature of the Earth 2,200 Years Ago (+Video)

Carl Sagan: Eratosthenes Figured out the Curvature of the Earth 2,200 Years Ago 

Rapper B.o.B. and astrophysicist Neil deGrasse Tyson made headlines last month when the two were embroiled in a high-profile back-and-forth about whether or not the Earth is flat — but apparently neither of them realized that Carl Sagan explained this whole round Earth thing to the world 36 years ago.

In an episode of Cosmos, 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 for experiment.”

Read more here: Carl Sagan Schooled BoB on His Flat Earth Theory More Than 30 Years 

http://news.yahoo.com/carl-sagan-schooled-bob-flat-223600071.html

Astronomy 101 Specials: Eratosthenes and the Size of the Earth
http://www.eg.bucknell.edu/physics/astronomy/astr101/specials/eratosthenes.html

Eratosthenes
https://en.wikipedia.org/wiki/Eratosthenes

Images credit: Getty, Reuters, Montreal Museum of Fine Arts – Bernardo Strozzi – Eratosthenes Teaching in Alexandria | by cerdsp
 and eg.bucknell.edu
Clip credits: ESO, ESA/HUBBLE & NASA

Image credit: NASA