Mysterious talk of quarks, spin and cats in boxes has given quantum physics a reputation as the scientific theory that no one really understands. Yet, as highly respected science writer Alastair Rae explains in this fascinating introduction to the quantum world, the practical applications of quantum physics are all around us in everyday life. Were it not for quantum physics, computers would not function, kettles would not boil, and power stations would not heat our homes. With a minimum of mathematics and an abundance of common sense, Rae offers a step-by-step guide to the basics of one of the most important theories of all time.Concluding with a tantalising insight into the philosophical problems, pitfalls and revolutionary potential of the new physics, this guide will provide the perfect introduction to quantum theory for readers of all backgrounds.