IS THE EARTH A PERFECT SPHERE...?

A person who thinks about the shape of Earth may have a doubt that is the Earth a perfect sphere or not...?

If you look around, the Earth looks flat. Even before the middle ages, people did think it was flat. The flat Earth concept persisted till about 300 years ago. In fact, people used to think that if they sailed too far in one direction, they would fall off the edge of the Earth! Pythagoras was the first person to talk about the Earth being spherical. A practical demonstration on Earth's sphericity was achieved by Ferdinand Magellan's  expedition's circumnavigation. It was Sir Isaac Newton, who first claimed that the Earth is not spherical, but 'oval'. Today, we know that the Earth is not a perfect sphere. It is slightly flattened at the poles, and bulges at the Equator.