As a boy, Einstein had imagined riding a beam of light and wondered if he would be able to see his reflection whilst holding a mirror. According to Newton, he would be moving so fast that light from his face, would not be able catch up with the mirror to become reflected back into his eyes. Travelling along at the speed of light, the wave front would appear frozen, however Maxwell had shown that light is an oscillating electromagnetic field and therefore such a stationary wave was impossible. Einstein resolved this conflict by realising that space and time are relative. This book is based upon a PowerPoint presentation that I gave, to convey the nature of this remarkable theory. Most of the explanation is given in terms of diagrams and simple descriptions, without much recourse to mathematics. It also acts as a prequel to my following book which deals with General Relativity. This and other physics titles (together with electronic downloads), are available from Lulu