Galileo Galilei was an Italian scientist whose work in the 17th century helped unlock many secrets of astronomy and natural motion. His successes were so great that he is known simply by the name Galileo.

Galileo’s achievements include: building the first high-powered astronomical telescope; inventing a horse-powered pump to raise water; showing that the velocities of falling bodies are not proportional to their weights; describing the true parabolic paths of cannonballs and other projectiles; coming up with the ideas behind Newton’s laws of motion; and confirming the Copernican theory of the solar system.

Galileo was a professor of mathematics at the University of Padua from 1592-1610 Because he believed that the planets revolved around the sun, and not the Earth, Galileo was denounced as a heretic by the church in Rome. He faced the Inquisition and was forced to renounce those beliefs publicly, though later research, of course, proved his theories correct.

Galileo’s works include Sidereus Nuncius (The Sidereal Messenger, 1610), Il saggiatore (The Assayer, 1623), and Dialogo sopra i due massimi sistemi del mondo tolemaico, e copernicano (Dialogue Concerning the Two Chief World Systems, 1632).