According to the laws of physics, time travel is possible, albeit a little troublesome and, because time is money, financially rather stretching. Physicist Paul Davies, shows how it can be done - without breaking the laws of physics and without any earth-shattering paradoxes - in this concise, step-by-step guide, illustrated throughout with explanatory diagrams. With the help of a handy black hole, or even better, a wormhole, and a bit of luck, this mode of travel could yet be a viable option.