I know you're getting at the whole "oblate spheroid" shape thing, but I'm pretty sure people have known it wasn't perfectly round for way longer than that. You

I know you're getting at the whole "oblate spheroid" shape thing, but I'm pretty sure people have known it wasn't perfectly round for way longer than that. You only need to look out a window to see hills and mountains after all (unless you live in the Netherlands ofc). Fun fact: the actual shape of the Earth is neither a sphere nor an ellipsoid but a "geoid", literally something "shaped like the earth".