At Pisa University, Galileo studied the physics of an Ancient Greek scientist, Aristotle. However, Galileo questioned Aristotle’s approach. Aristotle believes that the heavier objects fall faster through lighter mediums. Galileo eventually denied this idea by asserting that all objects, regardless of density, fell at the same rate in vacuum. To prove his opinion, Galileo conducted various experiments to drop objects from a certain height. In one of his early experiments, he rolled a ball over an inclined plane and then determined the distance of the ball within the same interval. He wrote his findings about the movement in his book, “De Motu”, which means “On Motion”.