Exactly 10 years ago, Peter Higgs learned that the subatomic particle named after him had finally been found. He was in Sicily, enjoying lunch in a restaurant. Outside, the stone streets of Erice burned in the midday sun; inside, a Dutch film crew was making a documentary about the boson he had described in a two-page research paper nearly half a century earlier. With Higgs was Alan Walker, another physicist who, since retirement, had served as a kind of personal assistant.
Walker stepped away from the table to take a call. When he returned, he quietly told Higgs that it had been John Ellis, a senior theorist at Cern in Switzerland, home of the Large Hadron Collider. He was urging them to come to Geneva for an event billed as an “update” on the search for the boson. “If John Ellis says that, then we should go,” Higgs replied. Four days later, on 4 July 2012, Higgs was sitting in Cern’s main auditorium as scientists working on the collider’s massive detectors reported the discovery of the Higgs boson – a particle that exists for about one ten-thousandth of the time it takes for light to cross a single atom.
“What had been conjecture for so long was now knowledge, knowledge about the fundamental nature of the universe that would be there for as long as humanity itself,” writes Frank Close. “The mysterious power of mathematics had been confirmed once more: the ability of equations written on pieces of paper to know nature.”
The audience burst into applause and cheers rang out. But the man whose work had been so spectacularly affirmed sank deep into his chair and refused to answer any questions from reporters – a sort of quantum vanishing act in which he was both there and not there. On the morning he was awarded the Nobel prize in physics the following year, Higgs, who has never owned a mobile phone, disappeared again. Having told colleagues he would be somewhere in the Scottish Highlands, he instead headed to a seafood bar in Leith, a couple of miles from his home, and quietly supped a pint of real ale while the Nobel committee frantically tried to reach him. Nine years later Higgs would claim that the discovery had “ruined my life”. “I don’t enjoy this sort of publicity,” he explained to Close. “My style is to work in isolation, and occasionally have a bright idea.”
Despite Close’s efforts, Higgs appears to have given him the slip too. A friend and colleague with hundreds of hours of conversation with Higgs to draw on, Close admits that his book, aptly named Elusive, became “not so much a biography of the man but of the boson named after him”. What might have been a weakness is in fact the book’s strength, for the tale of the conception and discovery of the Higgs boson, a tiny tremor in an energy field that pervades the whole universe, is one of the most important in modern physics. Without the Higgs there would be no atoms or people or planets or stars or anything except restless particles zipping through space in splendid isolation. Close, a particle physicist who has served as head of communications and public education at Cern, is an excellent guide to the knotty science of that story, as well as what we do know about the mysterious man himself.
Higgs was born on 29 May, 1929 in Newcastle upon Tyne, the only child of Tom and Gertrude. Plagued by eczema, asthma and bouts of bronchitis and pneumonia, he started school a little later than his contemporaries but was so well taught by his mother that he was put in a class with children two years above him. His health problems, isolation from other children and his precociousness (he taught himself algebra and calculus from his father’s undergraduate engineering textbooks) would help to mould him into a lifelong loner.
After the family moved to Bristol in 1941, Higgs was sent to Cotham secondary school – the same school attended by Nobel-prize winning physicist Paul Dirac three decades earlier. Both learned physics from the same teacher. Influenced by his father’s view that “Oxbridge was where the children of the idle rich went to waste their and their tutors’ time”, Higgs did not apply to Oxford or Cambridge and accepted an offer from King’s College London. Afterwards, he wanted to pursue theoretical physics but was told – wrongly – that research on elementary particles had hit a dead end and so he decided to study the spectra of helical molecules for his doctorate instead. His office was about four doors down from the laboratory of X-ray crystallographer Rosalind Franklin, whose research would contribute to the discovery in 1953 of the structure of another helical molecule – DNA. Only in 1955, when he moved to the University of Edinburgh, did he begin work in quantum field theory. After a brief stint back in London, he returned, spending the rest of his career in the Scottish capital.
The history of the Higgs boson begins, unexpectedly, with the theory of superconductors. During the 1950s, physicists showed how, at very low temperatures, electrons can couple together. These “Cooper pairs” nudge each other along in tandem, and this is what allows currents to flow through the superconductor without any resistance. One consequence of this is that photons, particles of light which normally have no mass, actually gain some thanks to a field generated by the interaction between Cooper pairs and their surroundings.
Close meticulously documents how these insights led Higgs to the idea that elementary particles such as quarks or electrons can also acquire mass through interactions with an omnipresent field. Higgs described this in two breakthrough papers in 1964. They amounted to about three weeks of work. “The labour was rather small,” he recalled later, “and I am staggered by the consequences.” Soon afterwards, he would discover that at least five other scientists had reached similar conclusions almost simultaneously. They included Belgian theoretical physicist François Englert, who would share the Nobel prize with him in 2013. Higgs’s distinction was to mention (in a single sentence) that his mass-giving field implied the existence of a giant boson and, in a third paper, to determine how that boson might quickly decay into lighter particles. This latter achievement provided a kind of fingerprint that experimenters could search for, sparking the decades-long quest.
After his insights of the 1960s, Higgs did no more work to develop his theory. “I became a bystander,” he tells Close. His focus shifted to university politics and the campaign for nuclear disarmament. He met his future wife Jody Williamson at a CND meeting in the university staff club in 1960, though they separated 12 years later.
The discovery of the Higgs boson was a glorious endorsement of the Standard Model, physicists’ best description of the subatomic world. Yet since that rapturous day in Geneva, the lack of a clear goal has left scientists feeling rudderless, Close says. Physicists know the Standard Model cannot be the final word. There is too much left to explain including, for example, the nature of invisible “dark matter” thought to account for the vast majority of all matter in the universe.
What next? Perhaps the Large Hadron Collider will catch a whiff of something before it is shut down at the end of the 2030s, a deviation from the Standard Model’s predictions that might indicate an exciting new physics lies just over the horizon. The other, more depressing, possibility is that the discovery set in train by the elusive Mr Higgs will not be surpassed for many decades to come.
• Elusive: How Peter Higgs Solved the Mystery of Mass by Frank Close is published by Allen Lane (£25). To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.
