7. The Shape of the Earth

In ancient times, people believed that the shape of the Earth was flat and it had steep edges. Today we know that the Earth is almost spherical. However, it is not a perfect sphere, rather it an oblate spheroid, bulging slightly at the equator and flattened slightly at the poles. The

difference between the equatorial diameter and the polar diameter is less than 44 km. The diameter of the Earth is 12,756 km at the equator, whereas it is 12,712 km between the poles.

This is due to the centrifugal force caused by the Earth’s rotation around its axis. This difference

is insignificant and thus for all practical purposes the Earth is taken as spherical in shape.

The view that the Earth is spherical in shape was first forwarded by the famous Greek philosopher, Phagoras, in the sixth century BC. But people did not believe him. Later, Aristotle, Varahamihira, Aryabhata and Copernicus also opined that the Earth is spherical in shape.