Human beings have a strong desire to travel through time. Although scientists are not yet taking out patents on a time machine, they are investigating whether it is possible under the laws of physics. In Newton's three-dimensional world this would have been inconceivable. But with Einstein's theory of relativity a fourth dimension - time - enters the frame. Is it really inconceivable that we can travel along the timeline? In this book Richard Gott offers an intellectually expansive study of the viability of time travel, which takes us from the dream of time travel itself in H.G. Wells's path-breaking novel The Time Machine to cutting-edge research into astrophysics and quantum teleportation. He explores the scientific, social and moral implications of time travel, and looks at recent remarkable experiments in which fundamental particles were actually sent into the future.