The strange shape of the Earth
What is the shape of Earth? Sounds like an easy question but it's not at all. The dispute over the shape of the Earth has been going on for millennia, because it is a far from trivial problem. Despite what the flat-earthers say, the hypothesis of the "spherical Earth" was already known in Antiquity: using a very ingenious geometric method, the mathematician Eratosthenes calculated the size of the Earth with amazing accuracy [1], wrong a few hundred kilometers only. A trifle, considering the method. All this in defiance of Christopher Columbus, who several centuries later blatantly misjudged his estimates, tried to reach the Indies by sea and was [...]
