New in paperback. Hardcover was published in 2012. Explains the science behind the discovery, looking at how the concept of a Higgs field was invented, how the vast experiment was carried out, and its implications on our understanding of all mass in the Universe. The book was written over the eighteen months of the CERN Large Hadron Collider experiment, with its final chapter rounded off on the day of the announcement 'that a particle consistent with the standard model Higgs boson has been discovered'. Foreword by Steven Weinberg.