A scene from “Unfinished Business”

Using nothing more than Newton's laws of gravitation, we astronomers can confidently predict that several billion years from now our home galaxy - the Milky Way - will merge with our neighboring galaxy - Andromeda. . . . Any life on the worlds of that far off future . . . would be treated to an amazing billion-year-long light show; a dance of a half a trillion stars, to music first heard on one little world, by a man who had but one true friend.