Let's dispel any flat-Earth myths.
In this video Carl Sagan explains how Eratosthenes of ancient Greece calculated the circumference of the Earth 2000 years ago.
I included an animation with the math/geometry in the next tweet for those interested. (1/2)
In this video Carl Sagan explains how Eratosthenes of ancient Greece calculated the circumference of the Earth 2000 years ago.
I included an animation with the math/geometry in the next tweet for those interested. (1/2)
Note that O is the shadow length and A is the obelisk height, which were known values. Nothing in the diagram is to scale. Made in PowerPoint. (2/2)
📷1-
📷2- me
#Science #educational
📷1-
📷2- me
#Science #educational
I know this video has been posted on Twitter before, but I figure you can't have too much of Carl! Dr. Sagan has always been a huge inspiration of mine. He was taken from us too soon.
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