From renowned physicist Fred Alan Wolf comes his enthralling and accessible exploration of parallel universes and the various theories surrounding them.In this "enthralling read" (Publishers Weekly), travel through the frontiers of space as physicist Fred Alan Wolf guides you through the complex yet intruging concept of parallel universes. Challenge your preceptions of the universe and explore ideas as varied as superspace theater and zero-time ghosts and even explore a future where time travel is real and black holes are gateways rather than endings.