Italian astronomer and mathematician ; demonstrated that different weights descend at the same rate ; perfected the refracting telescope that enabled him to make many discoveries ( 1564 - 1642 ) 意大利天文学家、数学家( 1564 1642 ) ;论证了不等重的物体下降速度相同;完善了折光式望远镜使他能够获得许多新的发现。