Peter Higgs, who predicted the existence of a new particle that came to be named after him (as well as God) and sparked a half-century, worldwide, billion-dollar search for it culminating in champagne in 2012 and a Nobel Prize a year later, died on Monday at home in Edinburgh, Scotland. He was 94.
The cause was a blood disorder, said Alan Walker, his close friend and fellow physicist at the University of Edinburgh, where Dr. Higgs was an emeritus professor.
Dr. Higgs was a 35-year-old assistant professor at the university in 1964 when he suggested the existence of a new particle that would explain how other particles acquire mass. The Higgs boson, also known as “the God particle,” would become the keystone of a suite of theories known as the Standard Model, which encapsulated all human knowledge so far about elementary particles and the forces by which they shaped nature and the universe.
Dr. Higgs was a modest man who eschewed the trappings of fame and preferred the outdoors. He didn’t own a television or use email or a cellphone. For years he relied on Professor Walker to act as his “digital seeing-eye dog,” in the words of a former student.
A half-century later, on July 4, 2012, he received a standing ovation as he walked into a lecture hall at the European Organization for Nuclear Research, or CERN, in Geneva and heard that his particle had finally been found. On a webcast from the laboratory, the whole world watched him pull out a handkerchief and wipe away a tear.
“It’s really an incredible thing that it’s happened in my lifetime,” he said on the webcast.
Declining to stick around for the after-parties, Dr. Higgs flew right back home, celebrating on the plane with a can of London Pride beer. CERN, which has shelves of empty Champagne bottles commemorating great moments lining its control room, asked if it could have the can, but Dr. Higgs had already thrown it away.
Peter Ware Higgs was born in Newcastle-upon-Tyne, England, in May 29, 1929, the son of a BBC sound engineer, Thomas Ware Higgs, and Gertrude Maude (Coghill) Higgs, who managed the household. He grew up in Bristol.
His interest in physics was tweaked when he was attending the same school, Cotham Grammar School, as had Paul Dirac, the great British theorist who was one of the fathers (there were no mothers) of quantum mechanics. That theory, which describes the forces of nature as a game of catch between force-carrying bits of energy called bosons, would be the same field in which Dr. Higgs would rise to fame.
At the age of 17, Peter moved to City of London School, where he studied mathematics. A year later, he entered King’s College London, graduating in 1947 with a bachelor’s degree in physics. He went on to earn his Ph.D. in 1954 for research on molecules and heat.
After temporary research posts at the University of Edinburgh, Imperial College London and University College London, he took a permanent job as a lecturer at Edinburgh in 1960. Dr. Higgs had come to love the city during his college days when he used to escape on hitchhiking trips to the Scottish Highlands.
During those years he also became active politically in the Campaign for Nuclear Disarmament and Greenpeace. But he dropped out of both when they grew too radical for his taste.
It was in the disarmament movement that he met and fell in love with a fellow activist, Jody Williamson. They married in 1963. She died in 2008. Dr. Higgs is survived by their two sons, Christopher, a computer scientist, and Jonathan, a musician, and two grandchildren.
At Edinburgh, Dr. Higgs redirected his research from chemistry and molecules to his first love, elementary particles.
Edinburgh was the birthplace of James Clerk Maxwell (1831-1879), who had accomplished the first great unification of physics, showing that electricity and magnetism were different manifestations of the same force, electromagnetism, which constitutes light. It would be Dr. Higgs’s fate to push physics to the next step, toward a theory that could be written on a T-shirt, by helping to show that Maxwell’s electromagnetism and the so-called weak force that governs radioactivity are different faces of the same thing.
As is often the case in the zigzag progress of science, however, that was not what Dr. Higgs thought he was doing.
“At the time,” he recalled in an interview in Edinburgh in 2014, “the thought was to solve the strong force.”
The strong force holds atomic nuclei together. According to theory, the particles that carry that force — bosons — should be massless, like the photon that transmits light. But while light crosses the universe, the strong force barely reaches across an atomic nucleus, which, by quantum rules, meant that the particle carrying it should be almost as massive as a whole proton.
So how did the carriers of the strong force become so massive?
Adapting an idea that Philip W. Anderson of Princeton had used to help explain superconductivity, Dr. Higgs suggested that space was filled with an invisible field of energy, a cosmic molasses. The field would act on some particles trying to move through it like an entourage attaching itself to a celebrity trying to make it to the bar, imbuing them with what we perceive as mass. Call it spooky action everywhere.
In some situations, he noted, a bit of this field could flake off and appear as a new particle.
His first paper on the subject was rejected, however, so he rewrote it, “spicing it up,” as he put it, with a new paragraph at the end emphasizing the prediction of the new particle, which would come to be called the Higgs boson.
It turned out that François Englert and Robert Brout, of the Universite Libre de Bruxelles, had beaten him into print by seven weeks with a similar idea. Shortly thereafter three more physicists — Tom Kibble, of Imperial College London; Carl Hagen, of the University of Rochester; and Gerald Guralnik, of Brown University — chimed in.
“They were first, but I didn’t know until Nambu told me,” Dr. Higgs said in an interview, referring to Nachiro Nambu, a University of Chicago physicist and also a Nobel laureate, who edited the journal. There was no internet then, he said, his voice trailing off, implying that if he had seen their paper he would probably never have written his own.
“At the beginning I wasn’t sure it would be important,” Dr. Higgs went on. Neither did anybody else.
In fact, theories of the strong force, which Dr. Higgs had set out to study, subsequently went another way. But his paper and his particle would be decisive for the so-called weak force.
Unknown to Dr. Higgs, the American physicist Sheldon Glashow had proposed a theory in 1961 that unified the weak force and electromagnetic forces, but it had the same problem of how to explain why the carriers of the weak part of the “electroweak force” weren’t massless.
Dr. Higgs’s magic field would have been just the ticket, but he and Dr. Glashow didn’t know each other’s work, although they had just missed each other.
One of Dr. Higgs’s duties as a beginning professor at Edinburgh in 1960 was to supply daily refreshments for a Scottish summer conference held there. Dr. Glashow, who was attending, and his friends would stash wine bottles provided by Dr. Higgs in a grandfather clock and then come back and stay up all night draining them and talking about the electroweak unification.
Dr. Higgs, meanwhile, was in bed. “I didn’t know they were stealing my wine,” he said in the interview.
The boson became a big deal in 1967 when Steven Weinberg, of the University of Texas in Austin, made it the linchpin in unifying the weak and electromagnetic forces. It became an even bigger deal in 1971, when the Dutch theorist Gerardus ’t Hooft proved that the whole scheme made mathematical sense.
Dr. Higgs said Benjamin Lee, a Fermilab physicist who later died in a car crash, christened it the Higgs boson during a conference in about 1972, perhaps because Dr. Higgs’s paper was cited first in Dr. Weinberg’s paper.
The name stuck, not just to the particle, but to the molasses field that produced it and the mechanism by which that field gave mass to other particles — somewhat to the embarrassment of Dr. Higgs and the annoyance of the other theorists.
“For a while,” Dr. Higgs recalled, laughing, “I was calling it the “A.B.E.G.H.H.K.H mechanism,” reeling off the names of all the theorists who had contributed to the theory (Anderson, Brout, Englert, Guralnik, Hagen, Higgs, Kibble and ‘t Hooft).
Interest in the boson came and went in waves. Dr. Higgs’s first round of interviews came in 1988, when CERN started up a new accelerator named LEP, for Large Electron Positron collider. One of its main goals was to find the Higgs boson. There was another round when LEP was closing down in 2000 despite claims by some scientists that they had seen traces of the Higgs boson.
Dr. Higgs was skeptical. “They were pushing the machine beyond its limit.” he recalled.
By then he had given up doing research, concluding that high-energy particle physics had simply moved beyond him.
He was trying to work on a fashionable new theory called supersymmetry, which would further advance the unification of forces, but “I kept making silly mistakes,” he said. Indeed, he told the BBC later that his lack of productivity would probably have gotten him fired long ago were it not known that he had been nominated for a Nobel Prize.
In recent years, Dr. Higgs lived in a fifth-floor apartment in the historic New Town neighborhood of central Edinburgh, around the corner from the birthplace of Maxwell, the great Scottish theorist, who grew up in the neighborhood.
Even before the Nobel sealed his place in history, he had become one of the tourist attractions of the city, a sort of walking monument to science, recipient of the 2011 Edinburgh Award for his “outstanding contribution to the city.”
Dr. Higgs continued to teach until he retired in 1996, but his lack of research kept him out of the fray and the fury that has resulted from the discovery of his boson. In 1999, he turned down an offer of knighthood, but in 2012 he was named a Companion of Honor by Queen Elizabeth II.
The next year he joined his idols Dirac and Maxwell in immortality by way of the Nobel Prize in Physics, which he shared with Professor Englert. But being in the fray was never his thing. On the day the physics prize was supposed to be announced, he decided that it would be a good time to leave town.
Unfortunately, his car wasn’t working. Stuck in town, he decided to go to lunch. But on the way a neighbor intercepted him and told him he had won the prize.
“What prize?” he joked.
Alex Traub contributed reporting.
