Galileo Galilei (1564-1642) is best known for his contribution to astronomy. He was the first to use the telescope to make detailed, accurate observations of the stars, which he used to confirm Copernicus's theory that the Earth orbits the sun. This brought him into conflict with the Roman Catholic Church, and he was placed under house arrest on charges of heresy.
Galileo also made advances in physics. Aristotle's belief that heavy objects fall faster than lighter ones was widely accepted until Galileo disproved it; however, the story that he did so by dropping weights from the top of the tower of Pisa is now thought to be apocryphal. Galileo's experiments in the motion of bodies laid some of the groundwork for Isaac Newton's breakthroughs in the field.