Discovered that Earth rotated on an axis.
Aryabhata was a great astronomer and mathematician from the Classical Age of Mathematics. His discovery that the world rotated on an axis was contrary to the then-popular belief that the sky rotated. He also stated that the sun and the moon rotate around the Earth. He also calculated the positions of the planets and their periods of rotation around the Earth. He was very keen on epicycles, which is a geometric model to explain the variations in speed and direction of the planets.
