who discovered that the earth rotates
The first person to do so ever was as early as the 3rd century BC by Aristarchus of Samos. Unfortunately, his notion gained only few supporters and was summarily rejected. Later in the 16th century, Nicholas Copernicus presented a mathematical model. In the next century, Johannes Kepler made inclusions of elliptical orbits, and Galileo Galilei presented supporting observations made using a telescope.