Throwback: Carl Sagan Shows How Ancient Scientists Proved The World Was Round

Are you one of those people who still believe the flat Earth theory? I really hope not, because Carl Sagan tells us that despite what we learned in grade school, even ancient civilizations understood the Earth was round. In the video below (thumbnail unrelated in video) Sagan explains how Eratoshenes (can we bring names like that back?) proved the Earth was round thousands of years before we would take flight and see it for ourselves. 

Pretty simple test! Makes me feel dumb that I would've never thought about it.