Galileo On Motion
At the University of Pisa, Galileo learned the physics of the Ancient Greek scientist, Aristotle. However, Galileo questioned the Aristotelian approach to physics. Aristotelians believed that heavier objects fall faster through a medium than lighter ones. Galileo eventually disproved this idea by asserting that all objects, regardless of their density, fall at the same rate in a vacuum. To determine this, Galileo performed various experiments in which he dropped objects from a certain height. In one of his early experiments, he rolled balls down a gently sloping inclined plane and then determined their positions after equal time intervals. He wrote down his discoveries about motion in his book, De Motu, which
means "On Motion."

Text, design, and layout by Megan Wilde for the Electronic Text Center. This biography is based upon information culled from The Galileo Project website.