Even the most reluctant readers will be fascinated to read about how twin astronauts Scott and Mark Kelly are a different age because Scott spent a year living on the International Space Station. This book looks at how time travel has been thought of from ancient times to modern day. It even discusses what humans might do if they could travel in time. From string theory to Einstein's theory of relativity, Heisenberg's uncertainty principle to the grandfather paradox, and wormholes to quantum physics, everything time travel related is discussed here in easy-to-understand language and complimented by vivid artwork on every spread.