Galileo's Telescope and the Trial of 1633

In 1609 Galileo Galilei, a professor at Padua, improved the newly invented Dutch telescope and turned it to the sky. His 1610 pamphlet The Starry Messenger reported mountains on the Moon, countless stars in the Milky Way and four moons orbiting Jupiter, showing that not everything circles the Earth. His later observation of the phases of Venus fitted a Sun-centered system. Galileo argued that scripture teaches how to go to heaven, not how the heavens go.

In 1632 his Dialogue Concerning the Two Chief World Systems seemed to mock the views of Pope Urban VIII, and in 1633 the Roman Inquisition forced him to recant and placed him under house arrest for life. Historians debate the meaning of the case: some see a clash of science and religion, while others stress personal politics, the tensions of the Counter-Reformation and Galileo's own combative style.