Galileo Galilei, the great seventeenth-century Italian astronomer, believed that the Book of Nature was written in mathematical characters; he was determined to read its true text through observation, experimentation, and inductive reasoning.
Early in his career, Galileo had accepted Nicolaus Copernicus's radical notion that the Earth revolved around the Sun. He was unwilling, however, to assert his belief publicly without tangible proof of the model. In 1609, Galileo reinvented the telescope and turned it to the sky to find evidence that the Earth was indeed in motion. He discovered sunspots and by tracking their movement he was able to offer visible confirmation of the Copernican model.
This proof gave Galileo scientific peace of mind, but it also brought him plenty of trouble. In 1633, he was tried and condemned by the Inquisition in Rome -- not to be restored to the Roman Catholic Church until centuries later in 1992. Galileo was forced to recant his Copernican position, and he spent his last eight years under house arrest. He never gave up his scientific quests, though, and, even after his eyesight failed in 1637, he continued formulating the theories that would become key building blocks for future scientists' ventures in gravitation, motion, and astronomy.
