International Year of Astronomy 2009

摘要

Four hundred years ago Galileo Galilei of Padua look a new technological device and directed it to the sky. In the summer, fall and winter of 1609, he undertook careful telescopic studies of the planets, the Moon and the stars. In the spring of 1610 he published a book describing his discoveries. In Sidenus Nuncius, he stated that the Moon has mountains just as the Earth, that the Milky Way was not a diffuse cloud of brightness but composed of faint individual stars, and that the planet Jupiter had its own set of regularly orbiting moons. Galileo's book revealed the unknown; he drew conclusions from his own observations even though those conclusions flew in the face of centuries of strongly held beliefs to the contrary. Its publication sparked others to build their own telescopes and turn them toward the heavens. The man who set physics on its way by making laboratory measurements of objects in motion jump-started modern astronomy with a new technological device and an open mind that gave precedence to observation over prevailing dogma.