Galileo Galilei
Italian astronomer and physicist tried by the Inquisition for championing a Sun-centered universe Show bio
Bio
Galileo Galilei noticed that a swinging chandelier seemed to keep steady time against his heartbeat. He then stumbled into a geometry lecture and, over his father's reluctance, swapped medicine for mathematics.
Galileo built his own telescopes and spotted Jupiter's four largest moons and the phases of Venus. He championed the view that Earth circles the Sun, which drew opposition within the Catholic Church.
Galileo made his case in the 1632 book Dialogue Concerning the Two Chief World Systems. He seemed to mock his old backer, Pope Urban VIII, and the Inquisition forced him to recant. Galileo spent his final years under house arrest, still writing about how things move.