From A to B may not seem a great distance to travel, but, as Robert Geroch demonstrates in his conversational style, our perception of distance is always relative to our position in space. For persons situated outside the speculative realms of physics and mathematics, Geroch's tour from A to B is a thorough introduction to Einstein's theory of general relativity. The early chapters are devoted to the development and modifications the crucial notion of space-time undergoes as it passes through the Aristotelian and Galilean viewpoints. From theories of absolute space and absolute time, Geroch than details modern ideas of a space-time in which neither space nor time is absolute, showing how our everyday conceptions are inappropriate to the physical world in which we live.