Generations have grown up knowing that the equation E=mc changed the shape of our world, but never understanding what it actually means, why it was so significant, and how it informs our daily lives todaygoverning, as it does, everything from the atomic bomb to a televisions cathode ray tube to the carbon dating of prehistoric paintings. In this book, David Bodanis writes the biography of one of the greatest scientific discoveries in historythat the realms of energy and matter are inescapably linkedand, through his skill as a writer and teacher, he turns a seemingly impenetrable theory into a dramatic human achievement and an uncommonly good story.