Galileo Galilei (1564-1642)

Italian astronomer and physicist. Used the newly invented telescope to observe moons of Jupiter, phases of Venus, and sunspots, providing observational evidence for heliocentrism. Insisted on experimentation and mathematical description of natural phenomena. Convicted of heresy by the Roman Inquisition in 1633 and forced to recant. Spent the rest of his life under house arrest. His trial became the canonical example of conflict between science and religious authority.