In June, 2007, a thirty-nine-year-old unemployed physicist named Garrett Lisi arrived at a professional conference in Morelia, Mexico, to give a twenty-minute talk. The conference was attended by all the top researchers in a field called loop quantum gravity, which had emerged as a leading challenger to string theory. Morelia is in a region susceptible to earthquakes, and it occurred to Lisi that if there was an earthquake string theory might predominate for the next twenty years. This thought was not pleasing to him.
Lisi had not been to a professional conference in eight years, and he was anxious about speaking in public. He has since learned that he can conquer this fear if he writes out all his remarks and reads from the script. But he hadn’t yet learned that tactic, and so he overcame his nerves by submerging his ideas in a mass of equations.
In the audience was a physicist named Lee Smolin, one of the three founders of the field of loop quantum gravity and a prominent member of the faculty at the Perimeter Institute for Theoretical Physics, in Ontario. Smolin had a bad cold that day, and so, through the double fog of his illness and of Lisi’s exceedingly technical language, he grasped only the contours of what he was listening to. Lisi believed that he had discovered what physicists call a Theory of Everything—a unifying idea that aims to incorporate all the universe’s forces in a single mathematical framework. The Theory of Everything has been the holy grail of theoretical physics for a century; Nobels are won for partial contributions to it. Here was somebody, with no reputation, saying that he might have figured out the key to the whole thing. Within four months, however, and after a second talk, Smolin was telling Lisi that he had “one of the most compelling unification models I’ve seen in years.”
“There’s a dream that underlying the physical universe is some beautiful mathematical structure, and that the job of physics is to discover that,” Smolin told me later. “The dream is in bad shape,” he added. “And it’s a dream that most of us are like recovering alcoholics from.” Lisi’s talk, he said, “was like being offered a drink.”
There is a persistent legend in physics of the hermit genius, the scientist who drops out of academia and then returns, many years later, with an insight that moves the discipline forward. The brilliant outsider has become almost a stock character. David Deutsch, a British pioneer of quantum computer theory, had dropped out of paid academia several years before his theories won wide acclaim. Julian Barbour, whose theories helped pioneer a key physics concept known as background independence, left the university and never returned, holding forth in a farmhouse twenty miles outside Oxford and receiving graduate students as pilgrims. The most famous outsider genius was the patent clerk Albert Einstein. “Look, in my experience, the style of a well-trained Ph.D. going away, thinking hard about something for a long time, and coming back with something very original, something that’s a well-worked-out and well-thought-through point of view, is an essential, if rare, part of how theoretical physics progresses,” Smolin said. “Garrett fit the pattern.”
But Lisi, when he arrived in Morelia, was so obscure that he could not think of a single reputable physicist who might recommend him for a job. Einstein at least had a weekly discussion club in Bern, where he muddled through Poincaré and Hume. Lisi had got his Ph.D. from the University of California at San Diego, completing his dissertation on the mathematics of the movement of water over a swimming dolphin’s skin, and then, at thirty-one, dropped out of academia and nearly out of society.
For almost a decade, Lisi moved on no fixed schedule between Maui, where he likes to surf, and the mountains of the West, where he snowboards. Four years ago, Lisi persuaded his girlfriend, Crystal Baranyk, who is an artist, to move with him into an old Colorado ski-shuttle van; he remodelled it himself, shipped it to Maui, and parked it by the beach. They lived in the van for a year, with no toilet. He worked intermittently, sometimes as a snowboard instructor, once on a short-term consulting contract when a friend’s software company needed an algorithm solved, but mostly he tried to think about physics. When Lisi arrived in Morelia, it was as if the Sierra Nevada and the physical sciences had joined to produce their own version of Sidd Finch.
“I am forty years old and most of my net worth is in snowboards and surfboards, and that’s kind of weird,” Lisi said. He wasn’t even particularly careful with these items. At one point, he was living in a yurt on a plantation in Maui with some people from the group World Wide Opportunities on Organic Farms when he found himself gripped by the urge to snowboard. He had no place to store his surfboards, so he just left them there. When he returned, a year later, he found that a new group had moved into the yurt, discovered the surfboards, and put them to use.
Five months after Morelia, Lisi finally published his theory online, in a thirty-one-page paper called “An Exceptionally Simple Theory of Everything.” The paper is hard for a nontechnical reader to penetrate; it consists mostly of equations and boasts. As physicists began to examine Lisi’s paper, they found it alternately sublime and just strange.
For half a century, scientists have tried, unsuccessfully, to unify the two governing theories of the physical world: general relativity, which explains the behavior of very large objects, like stars, and quantum mechanics, which precisely describes the phenomena of very small objects, like particles. The two theories are written in distinct mathematical languages, and scientists have not found a way to unify them—a common syntax. This makes it hard to describe certain crossover phenomena, like the horizons of black holes. Most physicists believe that the problem isn’t that the universe is incoherent but that there is something missing in the math.
Scientists have long hoped that new experiments in cosmology or particle physics would break this impasse. But discoveries on this scale haven’t been forthcoming, and it’s not clear that some of the most compelling modern theories can even be tested by experiment. This is particularly true of string theory. The appeal of the theory lies in its high-end math, but it also twists the real world in unusual ways. String theorists believe that the world has ten or eleven dimensions, depending on the version of the theory, with the extra ones balled up in “compactifications” too tiny to perceive.
Garrett Lisi, willfully cut loose from the world of academic physics, built his theory as an outsider might, relying on a grab bag of component parts: a hand-built mathematical structure, an unconventional way of describing gravity, and a mysterious mathematical entity known as E8. With the publication of his theory, Lisi wandered into a mill of expectations and press attention, in an unusually politicized moment in physics. His supporters include prominent physicists, but some of his antagonists, particularly among string theorists, thought his math was fishy and found the entire episode outrageous. When I asked the Nobel laureate David Gross, a professor of physics and an influential string theorist at the University of California at Santa Barbara, about Lisi, he said that he was “extremely reluctant to add fuel to this silly story.”
But Smolin, after meeting Lisi and talking to him, became convinced that it was at least possible that Lisi had made a fundamental breakthrough. “It is of the nature of a high-risk shot on goal from way down the field,” Smolin said. He wondered if a position within the academic world might buy Lisi time to develop his theory and asked if he was interested in applying for a university fellowship. Lisi said no.
In the acknowledgments to “An Exceptionally Simple Theory of Everything,” Lisi begins by thanking a mathematician from Columbia named Peter Woit. The two men had never met, and their only previous interaction was a slim exchange of e-mails that had ended some months earlier, in which Lisi sent Woit a description of the problems he was working on and Woit responded with some general words of encouragement. But in physics the invocation of Woit’s name was a smoke signal, a declaration of partisan affinities. Woit was best known for his zealous one-man campaign to discredit string theory. By thanking him, Lisi had enlisted in the string wars. “It was probably not the most politic thing to do,” Woit said.
Lisi had long harbored a deep skepticism about string theory. As a graduate student in theoretical physics at U.C. San Diego in the nineties, he was briefed on a recent string-theory development called the Maldacena conjecture by a young member of the physics department. “It was very interesting mathematics,” Lisi said. “But I remember walking out of this office and wondering what it had to do with any physical reality. And, as far as I could tell, it didn’t.” The influence of string theorists was growing at the time, and Lisi felt the academy closing in on him. “If you share an office next to a guy for twenty years, and you like him and you’re friends with him, it’s hard to tell him that you think that his whole idea of how the universe works is completely wrong,” he said. String theory, Lisi had come to believe, was “a mess.”
First during the nineteen-seventies, but with increasing momentum during the eighties, a loose community of physics researchers had begun to postulate that the disparate small particles that we learned about in high-school science class—electrons, for instance—were actually the varied vibrations of tiny open and closed looped strings. String theorists believed that this basic component allowed them to fit all the forces of nature into a single mathematical framework. By 1999, Steven Weinberg, a physicist and Nobel laureate at the University of Texas, could say that string theory was “the only game in town.”
One good way to prove string theory would be to look and see whether strings exist. But the vibrations, according to the hypothesis, take place at a frequency too high for existing equipment to detect. String theorists have still not been able to resolve their equations into testable hypotheses. Instead, they have built their case on the compelling quality of their mathematics, which some find almost incomprehensibly beautiful.
Physicists have long looked to higher math for insights into the workings of the universe. “If a figure is so beautiful and intricate and clear, you figure it must not exist for itself alone,” John Baez, a professor of mathematics at the University of California at Riverside, said. “It must correspond to something in the physical world.” This instinct—the assumption that beauty will stand in for truth—has become a habit. Some physicists now worry that string theory’s mathematics have grown permanently unmoored from the real world—an exercise in its own complexity. And so modern theoretical physics has become, in part, an argument about aesthetics.
By 2003, a series of papers had suggested that the ambitions of string theory might never be realized—that its equations had a number of possible solutions that neared infinity and could yield only “landscapes” of possible universes. For some, this was devastating. Physicists are scientists, after all, and, thirty years in, they were getting antsy for proof. But for many physicists these papers are far from decisive, and string theory retains much of its allure. “String theory still has great attractions, and there aren’t any alternatives,” Weinberg said. “Well, there are alternatives, but they’re worse.”
In physics, as in politics, the competition is crueller in lean times. “In terms of development of new theories, it has been maybe the slowest period in two centuries,” the science historian Spencer Weart said. By 2006, the fight over string theory had begun to leak out of the scientific community. Smolin and Woit published widely reviewed books criticizing string theory, and USA Today published an account of the assault headlined “HANGING ON BY A THREAD?” (There were “lots of bad puns,” Jacques Distler, a high-energy physicist at the University of Texas and a proponent of string theory, told me.)
For the critics, what had begun as an academic question had become a debate about what physics meant and what it should hope to uncover. Some physicists, including the leading theorist Leonard Susskind, concluded that our own universe was only a tiny corner of an unimaginably vast “megaverse,” which contained an almost endless number of universes, each structured according to different laws. In this context, the traditional search for a single Theory of Everything seemed almost quaint.
This was not Lisi’s position. He still had faith in the certainties of science. “The only thing that makes sense,” he said, “is if the universe is beautiful and simple and elegant.”
Lisi spent this past winter in Incline Village, Nevada, on the less hurried northern lip of Lake Tahoe, in a house he borrowed, rent-free, from a friend. From the deck you can see a sliver of the lake through an opening in the pines. Lisi went snowboarding three or four days a week at nearby Mt. Rose, where a season pass costs three hundred and thirty-three dollars, a comparative bargain. During the afternoons and on the weekends, when the slopes were crowded, he worked on his theory, usually from a beach chair draped with a towel. Crystal Baranyk often painted at an easel a few feet away. Lisi had become accustomed to the curious cadences of the resort—roaring with wealth a few weekends a year, its vast houses empty and silent the rest of the time.
As outdoorsmen go, Lisi is a creature not of adventure but of submissive, mind-clearing habit. He will ski the same slopes and surf the same break, morning after morning, for a whole season. When Lisi encounters a physicist of his own age whose skill he envies, he reminds himself that he is a better surfer. When he comes across a better surfer, he thinks, I’m much better at equations.
Last summer, when Lisi began to meet with physicists, they were struck by his personality, which is self-deprecating and ironic and not particularly hermitlike. “He has this enormous self-confidence, together with an unpretentiousness, which is indicative of someone who knows what he’s doing,” Smolin said. Lisi is stocky, handsome, and youthful-looking, with a shaved head and the same stubby-faced bulldog Italian look as the celebrity chef Tom Colicchio. He is a great admirer of the Myers-Briggs personality test, and believes that its assessment of him—INTP, or introversion, intuition, thinking, perceiving—is definitive. Lisi has spent most of his adult life as a libertarian but now considers himself somewhat more liberal than that. He is a committed atheist. He likes puns. Lisi doesn’t do any drugs or even drink; alcohol feels “like poison” to him. He makes a point of attending the post-hippie festival Burning Man. Although he returns to Maui and Tahoe regularly, his social networks, locally, are slim. The weekend I visited, Lisi and Baranyk were getting ready for a party in Reno, forty minutes away, to which they’d been invited by someone Lisi met on a ski lift, and for which they were dressing up as giant rabbits. But most nights they stayed in and cooked. They sometimes watched videotapes of the British science-fiction show “Doctor Who,” but they preferred board games. It is hard to meet Lisi without wondering why someone with so many social gifts, someone who so palpably enjoys the company of others, would choose to isolate himself so thoroughly.
When Lisi finished graduate school, he wanted to work on spinor fields, mathematical representations of particles like electrons, which had conventionally been expressed algebraically but Lisi thought might plausibly be expressed in more geometric terms. He could not find an established postdoctoral program that matched his research interests, however. In part, he believes, this was ideological: he was surrounded by string theorists. He briefly considered going to work outside physics, and interviewed with McKinsey, but the company was considering him for its office in Los Angeles, a city he didn’t care for. So he dropped out. His father, a probate attorney and a former Navy fighter pilot, in Escondido, California, and his stepmother were concerned. (His mother died when he was a baby.) His exile was, at first, conditional: if McKinsey had asked him to move to San Francisco, he might have gone. Six months later, he was in Hawaii, paying minimal rent to live in a house on the grounds of the Sudbury Maui school, where the children study independently. He spent some time encouraging a pupil who wanted to study the physics of baseball.
Lisi didn’t think that he would ever return to academic physics. “It’s publish or perish, and I figured I was perishing,” he said. He became accustomed to working in isolation, in air-conditioned public libraries, or in spare rooms at home, when he had a home. There were times when he lived in mansions near Colorado ski slopes, house-sitting. At other times, he pitched a tent in a friend’s back yard. He always figured, he told me, “that my brain wouldn’t let me starve.” But he was hardly thriving.
Lisi’s working life was not steady, or easy. “Ninety-five per cent of my time is virtually wasted,” he said. “If I were in a university, one of my colleagues would say, ‘No, that direction makes no sense—other people have looked into it, and it doesn’t go anywhere.’ Here no one stops me.” He spent weeks searching for a reliable place to work, and months on projects he later discarded. Sometimes he felt like a crazy person, walking down the pier in Santa Monica and muttering equations out loud.
But Lisi felt more and more that his isolated position had its advantages and might improve his chances of achieving something significant. He was convinced that academic physics had a bias against pursuing foundational questions at a young age, both because of the need to publish in order to get tenure and because such questions were seen as pretentious. And there was also, he believed, a bias toward string theory.
In 2002, three years out of graduate school, Lisi published a paper online. He described a way of formulating spinor fields in terms of geometric constructions known as Clifford bundles. Clifford bundles rely on a mathematical language developed by William Kingdon Clifford—a Victorian savant who wrote children’s stories about fairies—which is useful for describing rotations. (Today, its formulas are used heavily in computer graphics.) The paper didn’t make much of a mark. But Lisi felt that he had caught a glimpse of something bigger.
He wondered if his formulas might be expanded, so that he could use Clifford bundles to express the strong, weak, and electromagnetic forces. To others in the field, this would have seemed an odd exercise, like translating the Constitution into Esperanto and then expecting the new text to illuminate the law. But to Lisi it seemed revelatory. He began playing with a thirty-year-old description of gravity, the MacDowell-Mansouri approach, that fit well with Clifford bundles. What seemed to be correspondences appeared: particles and forces that he had previously thought of as wholly distinct blended together neatly when described using Clifford algebra. Lisi was seduced by the coincidences: there seemed to be a deep coherence in it somewhere. But he had also begun to recognize the closing down of possibility that comes with age.
By 2005, when Lisi published his next Clifford-bundle paper online, he was broke, and he and Baranyk talked about whether he should take a job teaching physics at a community college. The paper attracted little notice. But it did help land him a grant, a $38,640 check each year for two years, from a nonprofit group that funded foundational investigations in physics. Lisi was excited, but also frustrated. He hadn’t been able to fully describe his theory geometrically, and it wasn’t comprehensive. In the standard model, many particles have two related particles, the so-called second and third generations, and he hadn’t been able to include those. “I had this algebraic structure worked out, but I didn’t know what the hell it was.” For a year, Lisi said, “I scratched my head” and tried to figure it out.
One morning in May, 2007, Lisi woke up early and sat down with his laptop. Baranyk was still asleep. He began scrolling through Web sites that described topics in mathematical physics. He found a post, from 1996, in which a University of California professor had described the properties of mathematical structures known as exceptional Lie groups, among them E8.
E8 is famous in physics. The exceptional Lie groups had been classified in the nineteenth century by Wilhelm Killing, a German professor who joined the Franciscan order, as a way of describing higher-level symmetries. A circle has one degree of symmetry; a sphere has three; a space whose symmetries are described by E8 has two hundred and forty-eight. One rough way to imagine it is as a dense and precisely symmetrical cloud of spiderweb, with thousands of threads exploding out from hubs of concentric spheres. The equations that encode its inner structure, if printed in small type, would cover an area the size of Manhattan. During the nineteen-seventies and eighties, physicists had turned to E8 and a family of similar groups with great excitement (a major version of string theory makes use of E8). “It is like a diamond with tens of thousands of facets,” Bertram Kostant, an emeritus professor of math at M.I.T., said. “It is easy to arrive at the feeling that a final understanding of the universe must somehow involve E8, or, otherwise put, nature would be foolish not to utilize E8.”
Lisi began reading the description of E8’s structure and had a flash of recognition: the figure matched his mass of algebra precisely. “I saw that it fit. And saw it and immediately walked around the room, thinking of all the different ways that this thing fit together. And it was going to work.” As Lisi went through the numbers, he discovered, with a sudden thrill, that you could plot all the universe’s components on E8: each of those particles would correspond with one of its symmetries. It was as if a beachcomber, having spent years collecting driftwood, had suddenly realized that the pieces made up a complete shipbuilding kit.
Lisi was overcome. “I’m literally tingling with excitement,” he said. “I had to suppress that in order to think more about the actual algebraic structure. You cannot think when you’re ecstatic.” He added, “I didn’t run through the snow shouting ‘Eureka!’ or anything like that.” By the end of the day, Lisi was convinced that he had stumbled onto a Theory of Everything.
It took Lisi six months to work through the idea. He matched every photon, gluon, weak boson, graviton, Higgs boson, quark, neutrino, and electron, in each of the first, second, and third generations—every particle in the standard model—to symmetries of E8. He found that E8 had twenty more symmetries than the standard model had particles, and concluded that they indicated particles yet to be discovered. This led to a greater symmetry: on the terrain of E8, general relativity and particle physics were no longer out of joint. Lisi had his map for the universe.
Lisi saw the theory as a brief for non-absurdity in physics, and for accessibility. “Just our four dimensions, not ten, not eleven,” he said. “No strings. No tiny curled-up dimensions. Just the world that you see.”
For the first time since graduate school, Lisi started attending conferences. He went to Mexico, and then, in July, to a conference in Iceland, which drew a documentary film crew. “I’m walking around with this card that says ‘I’m Garrett Lisi and I’m working on a T.O.E.,’ ” he said. It didn’t get him much attention. He thought, as he walked past the film crew, “If you guys knew what I was up to, you’d want to talk to me.”
In the early nineteen-nineties, a physicist at Los Alamos named Paul Ginsparg had an idea for a better way to spread new findings in the field. Publishing in peer-reviewed journals took months. To compensate, scientists would copy papers they submitted and mail them off to colleagues, a process that was costly, slow, and limiting. Ginsparg created an online database of papers that, by 1999, had become known as arXiv. ArXiv uses moderators to look briefly at posted papers and make sure they’re in the correct topical forum, but it is otherwise largely unrefereed. Scientists are proud of arXiv for eliminating barriers in the discipline: relevant contributions come more frequently from scientists in places like Iran, India, and Turkey.
In recent years, as science reporters and interested amateurs have turned to arXiv—and as some physics personalities have started blogs—the audience for physics has both expanded and fragmented. “I know for a fact that many of the leading figures in the field read the blogs, but so do high-school science students,” Woit, the Columbia mathematician and string-theory critic, said. “The scary thing is how frequently you can’t tell which is which.” The leading blogs have readerships that, while including some loud dissenters, tend to align with the perspectives of their authors—Distler, of the University of Texas, has a blog that attracts many string theorists and enthusiasts, while Woit’s blog draws more skeptics. It works somewhat in the way the blogosphere operates in politics. Andreas Albrecht, a physics professor at the University of California at Davis, said that the blogs had opened physics to a new sort of populism, one that the academic establishment had to figure out how to manage. “It just pushes those buttons,” Albrecht said. “There’s some really good stuff, but a lot of really sloppy stuff.” What you have, in other words, is the erosion of the referee and the rise of a scientific underclass.
These are Garrett Lisi’s people. Last November, he posted his theory on arXiv. At first, it attracted little attention, though it did garner a certain amount of string-theorist scorn. A week later, a reporter at New Scientist (whose editor, as it turned out, had noticed Lisi in Iceland) published an enthusiastic piece on the paper, supported by a quote from Smolin; a science writer at the Telegraph immediately picked up the story, and wondered if Lisi might be the next Einstein. Hundreds of thousands of readers who had never logged on to arXiv before downloaded Lisi’s paper. The more attention Lisi received, the more aggressive his opponents on the Internet became. “Every high school senior excited about physics should be able to see that the paper is just a long sequence of childish misunderstandings,” Lubos Motl, a Czech physicist, wrote. “I understood these things when I was 14.”
Lisi had hoped that physicists would be excited about his ideas. “It’s been the best I could have hoped for. When I gave these talks, all the people whom I respected the most really liked it.” What he hadn’t expected was that other people would be interested, too. Lisi found himself the subject of profiles in science magazines and in Surfer. Discover asked, “Could the Next Einstein Be a Surfer Dude?” and—again with Smolin’s endorsement—listed him as one of “six top candidates” for that title. French science reporters seemed particularly taken with his theories, though Lisi found some of his interviews with them unnervingly surreal. There was a segment on a Fox affiliate, for which Lisi insisted that his parents, who are conservatives, be interviewed, and an invitation to appear on “Jimmy Kimmel Live,” which he declined. To his disbelief and pleasure, he was invited to speak at TED, an influential, invitation-only four-day technology conference in Monterey. (The TED curator, Chris Anderson, told me, “Not everyone understood him, but it still came over as pretty amazing.”) At a TED cocktail gathering, a man near Lisi nudged his wife and said, “That’s Garrett Lisi.” Glad to be recognized, Lisi introduced himself. The man was Pierre Omidyar, the founder of eBay.
A few days after the paper appeared on arXiv, Jacques Distler, the Texas string theorist, decided to look into Lisi’s theory. Distler had tried to ignore the fuss, but eventually concluded that he couldn’t. He told me, “I had the strong impression that the people writing those posts had not read the paper.”
First, he thought, Lisi hadn’t clearly specified which form of E8 he was using. And there was a second problem, which seemed more serious. Lisi had used a mathematical trick to incorporate the second and third generations of particles into his model. Lisi admitted, in his original paper, that this was a weakness, and that the math was what he calls “handwaving.” He saw his work on the second and third generations as provisional—certain calculations were still being worked out. He had already planned to spend the next months refining the fit. But to Distler it was damning.
In private e-mail conversations, Distler prodded Lisi for more detail. Lisi told me that he found the string theorist provocative and polite, and that he welcomed the questions about his theory. “My job should be to try to find problems with it,” Lisi said. On his Web site, Distler was less collegial; the more he looked, the more fundamental problems he saw. “Not only can one never hope to get 3 generations out of this ‘Theory of Everything,’ ” he wrote; “it appears that one can’t even get one.”
Part of the reason Lisi had such a following, Distler thought, was that some well-known physicists who were skeptics of string theory—Smolin and others—had “waxed enthusiastic” about him when reporters had called, and this triggered a cascade. “One can’t deny that the particular romance of this surfer dude played a part,” Distler said.
Lisi’s ideas leaned on several mathematical concepts heavily used in the loop-quantum-gravity community, and his project, if proved right, offered the prospect that their calculations might be expanded to encompass not just gravity but all the forces of nature. As quotes from Smolin and some other leading physicists, testifying to their excitement about Lisi’s theory, continued to appear in the press, it began to seem—to some string theorists, at least—that there was mutual opportunism embedded in all the awe: here was a surfer in search of credibility and a movement in search of a poster boy.
At the beginning of March, Lisi drove from Lake Tahoe to U.C.-Davis to give a talk on his theory to a seminar on quantum gravity. Looking around the campus, Lisi said, “It looks nice. If you’re visiting, you think, Wow, I could just hang here for a while and soak in some knowledge. A lot of people do play it that way, but those people tend to be students. Researchers tend to be very stressed out.” A couple of minutes later, he amended his judgment. “It is a really good life, and there are moments when I miss it.”
A full crowd of thirty or so students and professors gathered in the seminar room. Lisi had illustrated the presentation with an animated diagram of E8, its points flexing in correspondence with the particles, which were represented as bright-colored points on a black background, like the children’s game Lite-Brite.
“As a physicist, I have a fairly obvious question,” a bearded professor said.
“The Coleman-Mandula theorem, right? Wait a second,” Lisi said. He’d prepared a slide to deal with this very question. The students and the professors seemed less than satisfied, but the exchange was friendly enough. (Later, when I asked him about another professor’s question, Lisi was less patient. “A string theorist,” he said, dismissively.)
After the session, as the professors left the room, a small group of students began to cluster around Lisi. He told them how he had lived, on the cheap, in Maui. One of the students, a tall, commanding kid with a bush of curly hair, had relatives on Maui, and they talked about the rates that the shipping companies charged and how to game that system. Lisi, dispensing wisdom, looked a type: the bald, younger-than-his-years California guru. I’ve never seen him happier.
Yet, even among the early enthusiasts for Lisi’s ideas, there have been some defections. “I am now convinced his theory doesn’t work,” David Ritz Finkelstein, an emeritus professor of physics at the Georgia Institute of Technology, said. Finkelstein had earlier told New Scientist that “some incredibly beautiful stuff falls out of” Lisi’s theory. And while others were still confident about the sweeping nature of his theory, some were making the lesser claim that even if Lisi couldn’t fix the math, his novel approach to E8 could yield insights into the universe’s basic makeup. The thrill was modulated, but it wasn’t gone.
Kostant, the M.I.T. professor, is unaffiliated in the string wars. “Columbus made mistakes and thought he was in India. Lisi made a few errors, but this pales in significance to his possibly opening up a whole new world for exploration,” Kostant said. “E8 is like North America, South America, and the Pacific Ocean rolled into one. No one in Europe knew anything about it.” Lisi’s “daring,” Kostant said, “possibly creates an agenda for scientists for the next hundred years or more.”
Smolin, who had been so instrumental in ushering Lisi’s ideas into the public square, expressed regret that they had arrived there before they were fully formed. He found himself pleading for some time and space for Lisi, to allow him to revise and complete his theory—to give it the attention it warranted. “Then we can know: has Garrett made a really great discovery, or was it a miss?”
Part of Lisi’s charm is his all-terrain bonhomie. But his fortieth birthday, in January, coincided with some dark thoughts. His body had become slower to recover from injury and stiffer at times, which was a big deal for someone who had arranged his life, more or less, around exactly how good it felt to move. He began to feel a set of responsibilities—to the broader physics community and to those who had supported him, but also to fully extending his ideas. Lisi had long fantasized about opening a “science hostel,” a big empty house in a beautiful place, like Tahoe, where scientists would gather to do research. He began to think that, somehow, the attention he’d been getting might help to make the hostel a possibility. Last May, Lisi headed to the Perimeter Institute, for a stint as a visiting researcher. A year ago, he wouldn’t have even thought of returning to academia, but he had begun to consider it.
This summer near Geneva, the Large Hadron Collider, the most powerful machine of its kind ever built, will be turned on, and begin smashing protons into one another. It will take years for the data to be analyzed, but rumors of the results will leak out and find their way onto the Internet. The L.H.C. contains the aspirations of several camps of particle physicists, who hope that it will offer some confirmation for their theories. Lisi will join them. His theory is still incomplete—missing, for example, a satisfying link to the second and third generations. But it makes predictions about particles that the L.H.C. might discover: new versions of the Higgs boson, for one.
Lisi had recently listened to a talk by an expert on E8, and he now believed that one of its alternate forms might be a better fit for the universe. He showed me a pad on which he was trying to work out the math. I asked him if there would still be twenty missing particles. No, he said. “There will be more.” ♦
