Galileo Galilei

Galileo Galilei (1564–1642) was an Italian astronomer, physicist and mathematician. Born in Pisa, he taught mathematics at Pisa and Padua and studied motion, falling bodies and the pendulum. In 1609 he built a telescope, and the discoveries he announced the following year in The Sidereal Messenger, the moon's mountains, countless new stars and four moons of Jupiter, made him famous and won him a post at the Medici court. His defense of the Copernican system in the Dialogue Concerning the Two Chief World Systems led to his trial by the Roman Inquisition in 1633 and house arrest for the rest of his life, when he completed Two New Sciences.