Forget everything you thought you knew about reality. The world is a seriously bizarre place. Things can exist in two places at once and travel backwards and forwards in time. Waves and particles are one and the same, and objects change their behaviour according to whether they are being watched. This is not some alternative universe but the realm of the very small, where quantum mechanics rules. In this weird world of atoms and their constituents, our common sense understanding of reality breaks down - yet quantum mechanics has never failed an experimental test. What does it all mean? The Quantum World explores the past, present and future of quantum science, its applications and mind-bending implications. Discover how ideas from quantum mechanics are percolating out into the vast scale of the cosmos - perhaps, in the future, to reveal a new understanding of the big bang and the nature of space and time.