How the hunt for the Higgs boson began

In this excerpt from Massive: The Missing Particle That Sparked the Greatest Hunt in Science (Basic Books), author Ian Sample tells the story of how Peter Higgs went from being a joke to a legend with just one lecture.

Peter Higgs arrived in Chapel Hill to set up home on September 6, 1965, having left Jody, who was heavily pregnant at the time, with her parents in Urbana, Illinois. At the university, he set about writing his first major paper on the origin of mass. On September 24 he was working in the library of his new department when he was called to the phone. His first son, Christopher, had just been born. Higgs finished the paper in November and sent a copy for publication and a few more to physicists he thought might be interested.

Though it wasn't clear at the time, Higgs's theory pointed to a critical moment in the birth of the universe. In the immediate aftermath of the Big Bang, the cataclysmic explosion that flung the universe into existence, the elementary particles were entirely massless. Then, a fraction of a second after the Big Bang, something happened: an energy field that permeated the fledgling universe switched on. Massless particles that had been zipping around at the speed of light were caught in the field and became massive. The more strongly they felt the effects of the field, the more massive they became. Most scientists concur that time began about 13.7 billion years ago, possibly with the first bang there ever was, but perhaps as just one of many bangs that occur in a cyclic process.

The universe, at first a microscopic ball of intense energy, was too hot for the laws of nature as we know them to yet emerge. But in the blink of an eye (had there been one around to oblige) the cosmos grew to the size of a beach ball and cooled just enough-to around ten thousand trillion degrees Celsius-for the Higgs field to come to life. In that eye-blink, the first building blocks of matter were tamed-made heavy and slow, like flies in soup.

The Higgs field is crucial to the structure of the universe and its ability to support life as we know it. Without the field, the elementary particles, the building blocks of matter, would behave like light. The chemistry we are familiar with would not be possible.19 Matter would not have clumped together into the atoms we see today. Stars and planets would not have formed. The universe would be a lifeless wasteland.

At the heart of Higgs's theory was a new particle associated with the mass-giving field. The Higgs boson, in a sense, is the part of the field that is left over once the field has given mass to particles.20 The best hope scientists have of showing Higgs's theory to be right is to show that the particle exists.

Not long after Higgs sent his paper out to academics, a letter arrived at his office in Chapel Hill. It was from Freeman Dyson, the English-born mathematician who had worked at RAF bomber command in World War II. Dyson had crossed the Atlantic at the age of twenty-three, clutching a letter declaring him the best mathematician in England. He had since become an eminent professor at Princeton's Institute for Advanced Study.

Dyson's letter was amiable and could not have been more flattering. He explained how he'd enjoyed Higgs's latest paper and that it made clear things he'd been puzzling about for some time. He asked if Higgs would give a seminar on his theory at the institute that spring. Higgs was astonished but accepted without a second thought. Dyson's enthusiasm for Higgs's work didn't mean he was in for an easy time at the Institute for Advanced Study. The institute was home to some of the brightest physicists in the world, and some of them were certain to disagree with Higgs's theory. Renowned scientists had flocked to the institute since Louis Bamberger, an American philanthropist, had established it in the 1930s. Its most famous resident, Albert Einstein, who had died in 1955, had spent the last twenty-five years of his life there, trying to explain how the forces of nature were born. The Austrian-American logician Kurt Gödel was still there, redefining the limits of human knowledge. He and Einstein had been friends, though he had vexed Einstein by pointing out that his famous theories allowed time travel to be possible. The father of modern computing, John von Neumann, was also at the institute, turning the mathematics of poker into a political strategy to win the Cold War.

Robert Oppenheimer, the towering figure who had led the Manhattan Project to build the atomic bomb, had become head of the institute in 1946, only adding to the intimidating aura of the place. Oppenheimer was renowned for his short temper and sharp tongue and could be at his worst when he turned up for the weekly seminars that were held on the campus. It wasn't unknown for him to bully less self-assured speakers, quizzing them relentlessly and correcting them before they had a chance to respond. It was a character trait Dyson despised, and it occasionally triggered rows between the two men when seminars were over. "Oppenheimer always tried to tell you what you would have said if you were as clever as Oppenheimer," Dyson recalled.

As Higgs drove on, his mind wandered to the talk he would give the following day. The audience would be unlike any he had spoken to before. When Higgs returned his attention to the road, he was gripped by a surge of panic. Afraid he was about to lose control of the car, he pulled over. On the side of the road, he took a few deep breaths and tried to regain his composure. Higgs had just seen a road sign. The exit for Princeton was only a mile ahead. He was nearly there.

The Institute for Advanced Study sat amid 800 acres of landscaped gardens a mile outside of Princeton. Instead of driving directly there, Higgs took a detour into the town and parked his car. He found his way to a post office and had a word with the clerk. From behind the counter, the man produced a first-day cover of the violet eight-cent stamps that had been issued that day in commemoration of Einstein. Einstein, it turns out, had been born on that date in 1879, so the post office had carefully chosen both the date and the place of issue for the stamps. Each carried a picture of the great physicist taken twenty years earlier by Philippe Halsman, a family friend who had served time in an Austrian prison for killing his father on an Alpine hike. The stamps irked Higgs because they referred to Einstein as a "prominent American." Although Einstein had taken U.S. citizenship in 1940, Higgs considered him a European at heart. Nonetheless, he thought the gift would go down well with his friend and mentor Nicholas Kemmer back in Edinburgh and he duly posted it back to Scotland.

It was approaching evening when Higgs pulled up at the institute, where he and Jody met Freeman Dyson. The three got on well and Higgs soon forgot the nerves that had overcome him on the drive there. When they were done chatting, the Higgses went to their lodgings and collapsed into a much-needed sleep.
Higgs's talk was scheduled for 4:15 P.M. the following afternoon. When he arrived he saw that Dyson himself was down to speak first. The talk was highbrow, on the stability of matter, but it addressed a simple enough question: how is it that the objects around us stay intact, considering that they contain countless particles held in place by finely balanced yet extraordinarily powerful forces? Why doesn't this book, with the enormous amount of energy locked up in its atoms, suddenly tear itself apart? Why don't your clothes spontaneously explode into a zillion subatomic fragments?

Dyson wrapped up his brilliant lecture and opened the floor for questions. As expected, the audience was sharp and challenging. Their skills had been honed by something of a tradition at the institute, weekly lectures with the intriguing name of Shotgun Seminars. At these lectures, no one knew who the speaker would be until a name was drawn from a hat. The presentations were popular, but there was a catch: every member of the audience had to put his name into the hat and be ready to give the seminar if his name was the one drawn. Everyone was fired up to speak, but those who were not chosen were equally fired up to grill whoever took the floor.

When the audience had exhausted its supply of questions, Dyson called a tea break and announced that their guest, Peter Higgs, was up next. As a special guest, Higgs knew he would be presenting. He joined the crowd for refreshments and over a cup of tea fell into conversation with a German physicist named Klaus Hepp. The two had met once before at a summer school in Scotland in 1960. As the two sat chatting, Hepp mentioned a paper that was about to be published by three highly regarded scientists. It was, he was sorry to say, a body blow for Higgs's theory. "There's no doubt about it," Hepp said, as the two made their way back to the lecture hall. "You've got something wrong."

At least Oppenheimer wasn't around. Higgs had no idea, but the bullying director was gravely ill with cancer and was to formally step down three months later. At the podium, Higgs collected his papers and, step by step, took the audience through his theory. Dyson listened intently. He thought Higgs's work was beautiful. When their guest had finished speaking, several hands shot up around the room. Although Higgs was anxious about the seminar, there was an underlying confidence in his manner. He knew the equations in his theory so well he could feel their deeper meaning. He was sure the ideas he put forward were sound. That didn't mean they were true, of course. Many things that are theoretically possible are not realized in nature. But if the theory was flawless, it was at least a contender for describing the origin of mass.

The questions from the audience were insightful, probing, and critical, but none exposed any mistakes in Higgs's logic. His theory had passed its most challenging test yet. Dyson thanked Higgs for speaking and closed the session, delighted that the talk had gone well. Later, Higgs heard that Arthur Wightman, a leading physicist in the audience, had told his colleagues they had better go back and check their "proof " that contradicted Higgs's theory. He had believed every word Higgs had said.

The next day, after dinner with the Dysons, Higgs took to the road again. A second invitation had arrived from Harvard University, where the prominent and playful physicist Sidney Coleman worked, and Higgs had agreed to drop in for an open discussion before heading back to Chapel Hill. The talk had been scheduled for the afternoon, which wasn't unexpected. Coleman famously missed morning appointments and once explained his failure to give a 9 A.M. lecture by protesting that he couldn't possibly stay up that late. Coleman was hoping to have some fun with Higgs. He later confessed that he'd told his students some idiot was coming to see them. "And you're going to tear him to shreds!"

The mauling never happened. At Harvard, Higgs's talk turned into an enthusiastic discussion that everyone participated in. Once more, the theory stood up to scrutiny. If the audience began with hopes of pulling it apart, they finished with a sense of intrigue. Higgs's theory was a watershed moment in physics, one of those crucial steps that opens a door to a new world where discoveries are there for the taking.

Want to read more? You can pick up a copy of Massive via Basic Books, or at your favorite bookstore.