Nobel Prize-winning physicist who predicted the God particle
Peter Higgs was walking in the Scottish Highlands in 1964 when he came up with a theory for how particles acquire their mass. As he would often point out, two other groups of physicists had proposed the same idea at almost exactly the same time (one just before him, one just after). What distinguished his contribution, said Harald Fox on The Conversation, was that he predicted the existence of a massive subatomic particle (a form of boson) left behind by this process. In the following decades, theoretical physicists joined in an almost obsessive quest to detect this particle. But the Higgs boson proved so elusive that the physicist Leon Lederman dubbed it the “Goddamn particle” – which was then shortened to the “God particle”.
Higgs, who was an atheist, felt that this nickname was inappropriate and misleading; but it did encapsulate the importance of what he proposed. Without the God particle, said The Daily Telegraph, “the entire framework of the Standard Model of Particles and Fields, the theory that has been used to explain fundamental physics since the 1970s, fell down”. The name also helped attract popular interest in the subject – and conveying what it all meant in layman’s terms became a pastime in itself for scientists in the field. In 1993 the then-science minister, William Waldegrave, offered a bottle of vintage champagne to anyone who could explain the Higgs boson on a single side of A4, to help him get funding for the search. “With a great deal of creative flair, the competition entrants turned to analogy, poetry, rhyming verse and limericks.” But most people were still left scratching their heads.
By the mid-1960s, the Standard Model contained a “particle zoo” populated by electrons, protons, bosons and various quarks that form the building blocks of nature, said Space.com. But one particular question remained unanswered – why do some particles have mass? This question was vitally important, as without that mass there would be no atomic elements, no stars, no us. The solution that emerged in the 1960s (the Brout-Englert-Higgs mechanism) was that fundamental particles acquire mass via interactions with a quantum field, the Higgs field, that permeates space. In Waldegrave’s competition, the winning entry likened the field to a cocktail party at the Tory conference, and Mrs Thatcher walking through it, gathering hangers-on.
Higgs suggested that the introduction of this theoretical wave meant that a previously unknown particle with no intrinsic spin would sometimes appear: the Higgs boson was that particle, and detecting it would prove the theory and complete the Standard Model. This, however, was not easy. With a lifetime of less than a billionth of a billionth of a second, the particle could not be observed in nature. Instead, scientists had to try to create it by replicating the high-energy conditions of the early universe – and detect its traces. Vast sums were spent building particle accelerators, culminating in the Large Hadron Collider at Cern, and billions of collisions between protons accelerated to light speed were analysed. Finally, 48 years after Higgs wrote his paper, scientists hit pay dirt on 4 July 2012. Arriving at Cern to hear the news, Higgs received a standing ovation and, on a webcam broadcast around the world, could be seen wiping away a tear. Then this modest man, who detested publicity and who didn’t even own a TV, flew straight home. The next year, he and François Englert (the surviving author of the paper that came out just before his) were awarded the Nobel Prize in physics. Typically, Higgs made sure to be out that day, to avoid the media fuss.
Peter Higgs was born in 1929, and grew up in Bristol, where his father worked as a BBC sound engineer. He became interested in quantum mechanics at Cotham Grammar School when he noticed that one of its alumnae was one of the field’s pioneers, Paul Dirac. He studied physics at King’s College, obtained his PhD, and then in 1960 took up a position at the University of Edinburgh. He also joined CND, and fell in love with fellow anti-nuclear activist Jody Williamson, an expert in linguistics. They married and had two sons; and although they later separated, they remained close until her death in 2008. As media interest in Cern and the God particle intensified, Higgs became famous – and practically an Edinburgh tourist attraction in his own right. He hated that, said Nature, but he was proud of the work that brought him fame.