The revolution in twentieth-century physics has offered answers to many of the big questions of existence, such as the ultimate nature of things and how the universe came into being. It has undermined our belief in a Newtonian mechanistic universe and a deterministic future, posing questions about parallel universes, time-travel, and the origin and end of everything. At the same time we have witnessed amazing attempts at unification so that physicists are able to contemplate the discovery of a single theory of everything from which we could derive the masses and types of all particles and their interactions. This book tells the story of these discoveries and the people who made them, largely through the work of Nobel Prize-winning physicists.