Galileo Galilei is an important forefather to much of what we know today about physics and astronomy. In fact, he was one of the first people to claim that the sun was the center of the universe, not the Earth. He was also the first to use the telescope to examine celestial bodies. Finally, he realized that in a vacuum, if two different weighted objects were dropped, they would land at the same time. Those are just a few of his many accomplishments.