Galileo Galilei

Galileo Galilei (1564–1642), Italian mathematician and physicist who discovered the laws of falling bodies and the parabolic motion of projectiles. The first to turn the newly invented telescope to the heavens (1609), he was among the earliest observers of sunspots and the phases of Venus. A talented publicist, he helped to popularize the pursuit of science. However, his quarrelsome nature led him into an unfortunate controversy with the Roman Church. His most significant contribution to science was his provision of an alternative to Aristotelian dynamics, expressed in his Dialogue Concerning the Two Chief World Systems (1632). The motion of the earth thus became a conceptual possibility, and scientists at last had a genuine criterion for choosing between the Copernican and Tychonic hypotheses in astronomy. In 1633, the Vatican condemned Galileo as a heretic for claiming that the earth revolved around the sun. He was forced to recant the Copernican theory. Pope John Paul II started the move toward a reconciliation when he conceded in a 1979 speech that the astronomer had suffered at the hands of the Church. In January 1998, the archives of the papal inquisition, until 1902, were made accessible to researchers. It was expected that the archives would provide new insights regarding the trial against Galileo.