It was around 250 BCE when Eratosthenes was a librarian in the famous library ... One can understand that if the earth is a sphere. In fact, from the angle of the sun’s rays from the vertical on June ...

which gives the Earth’s circumference to be about 39,830 km which is more accurate than Eratosthenes’ calculation of about 39,690 km», an article published by Thinkib revealed. The estimation ...