The relationship between Galileo Galilei and Isaac Newton is like that of two complementary stages of a rocket. Galileo, the argumentative "wrangler" who demanded that the universe be examined through a telescope rather than by means of a philosophy book, provided the first liftoff, and Newton, the secretive mathematician who searched among his notes to find a mislaid proof for universal gravitation, put the world into orbit. Here, from award-winning journalist William Bixby, are their stories.