The Particle at the End of the Universe
By Sean Carroll
In his latest book, Sean Carroll, author of the brilliant From Eternity to Here, has produced an accessible read aimed at the layperson interested in an up-to-date account of the state of particle physics and, in particular, the discovery of the Higgs boson. Carroll is well placed to offer the reader an in-depth view of the world of particle physics, being close enough to give a personal account yet maintaining the perspective of an onlooker. As a result he is a superb advocate of the case for “Big Science”, which he demonstrates to full effect in both the opening and closing chapters of the book, beginning with several snapshots of physicists celebrating the milestones that led up to the announcement of the major discovery at CERN on 4 July 2012.
By interweaving the scientific concepts with chapters on historical, social and political aspects of particle physics, Carroll dilutes the hard bits with human interest, appealing to the widest possible audience. He conveys the central importance of the Higgs discovery before going into the theory in any detail, so that we get an idea of what the fuss is about. He explains that the particle at the end of the universe is not a reference to the Higgs boson’s location in space or time but rather its location in our understanding, as the final piece of the Standard Model. This marks the end of the journey to describe our everyday surroundings and the beginning of a new era of full discovery. The theme is developed further when Carroll gets into his stride with dark matter, supersymmetry and string theory, demonstrating how the Higgs particle can act as a portal for exploring as yet unreachable phenomena.
True to the headline-grabbing comments of intrigue and drama in high-energy physics on the cover, the book recounts the chequered history of accelerators: the engineering challenges and the agonies of having your machine switched off when a major discovery could be just around the corner; or the frustrations of not getting the machine built at all, as with the Superconducting Super Collider. In this way, the account does justice to the magnitude and achievements of the LHC and its experiments.
What is meant by the “discovery” of a particle is also explained clearly, together with the issues concerning the timing and control of such announcements, especially given the high level of public interest. Concerning the difficulties of apportioning credit, Carroll proposes that scientific collaborations should be allowed to win the Nobel prize and that “Whoever gets that rule change implemented might deserve the Nobel Peace Prize”.
A couple of errors should be mentioned: the Higgs boson is repeatedly credited with distinguishing the electron from the neutrino and the up quark from the down, etc. The important qualification that this statement holds true only for the left-handed components of these particles is mentioned only latterly. Also, there is an unfortunate sign error in the diagram of Fleming’s left-hand rule – not a big deal in itself but enough to undermine confidence in the book for some readers, perhaps giving the impression that it has been rushed into print.
With this book Carroll consolidates his position as an exceptionally talented writer of difficult physics concepts for the layperson. He weaves together fascinating facts, amusing anecdotes and insightful analogies. In storyteller style, with colourful characters and thrilling plots, he propels the reader along the journey that particle physics has made in our lifetime. The layperson can empathize with the emotional highs and lows of research, the patience and tenacity required to bring a project like the LHC to completion and the laudable level of co-operation that the particle-physics community demonstrates to other large and complex organizations – to quote: “If only the United Nations could work like CERN, the world would be a better place.”