The earth is flat??
Carl Sagan shows how Eratosthenes 2200 years ago was able to deduce the circumference of the earth based on two obelisks 800 km apart.
Science
Science and stuff
Science and stuff
Carl Sagan shows how Eratosthenes 2200 years ago was able to deduce the circumference of the earth based on two obelisks 800 km apart.