Human beings have a strong desire to travel through time. As an acknowledged world expert in the topic, Professor Richard Gott is rumoured to have a time machine in his garage, and he was once sent a letter inviting him to give a talk on the subject six months after he had already done so. But time travel has a serious side too. He often receives calls from people who want to return to the past to see a loved one. 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, witty and engaging 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. Finally he reveals how the study of time travel to the past may provide new insights into cosmic origins and evolution.