The revolution is here. In breakthrough after breakthrough, pioneering physicists are unlocking a new quantum universe which provides a better representation of reality than our everyday experiences and common sense ever could. The birth of quantum computers – which, like Schr dinger’s famous dead-and-alive cat, rely on entities like electrons existing in a mixture of states – is starting to turn the computing world on its head.In his fascinating study of this cutting-edge technology (first published as Computing with Quantum Cats and now featuring a new foreword), John Gribbin updates his previous views on the nature of quantum reality, arguing for a universe of many parallel worlds where ‘everything is real’. Looking back to Alan Turing’s work on the Enigma machine and the first electronic computer, Gribbin explains how quantum theory developed to make quantum computers work in practice as well as in principle. He takes us beyond the arena of theoretical physics to explore their practical applications – from machines which learn through ‘intuition’ and trial and error to unhackable laptops and smartphones. And he investigates the potential for this extraordinary science to allow communication faster than light and even teleportation, as we step into a world of infinite possibility.