Geocentrism - The Origin of the Earth

In the first millennium b c several cultures began to realize that the earth isn't flat, but is actually a sphere. This happened in greece, india and china, for example. Greeks also started doing calculations to do things like estimate the size of the earth and the distance to the sun. Around 200 forty b c, the astronomer aritosthenes used the shadow of the sun on the summer solstice to calculate the circumference of the earth as 250 thousand stadia. So the first element of the primitive world view, the idea that the earth is flat, was now replaced by the belief that it's a globe.