Galileo was an Italian scientist whose work in the 17th century helped unlock many secrets of astronomy and natural motion. 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. 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. His 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).
The Vatican officially recognized the validity of Galileo’s work in 1993… Galileo was a professor of mathematics at the University of Padua from 1592-1610… Others had invented very low-power telescopes before Galileo, but he refined and improved the idea so greatly that he is generally considered the inventor of the modern telescope.