For some people, charting the topography of the universe is easier than locating the wormholes in their own apartments. Brian Greene, a boyish, mediagenic Columbia physics professor, is wandering helplessly around his living room in Morningside Heights, trying to find an autographed picture of John Lithgow. He scans the bookcase, whose shelves are studded with hiking guides, Camus novels, and videotapes of physics symposia from all over the world. He pulls down a stack of folders, lecture notes, and yellowing newspapers, and begins to sift.
Greene received the photograph a year ago, after helping a Hollywood friend punch up some dialogue for NBC’s 3rd Rock From the Sun. On the show, Lithgow plays a crackbrained physics professor from outer space, and as a point of professional pride, he likes his science patter to make sense. Greene was delighted to pitch in. He’s always had a peripheral interest in show business. In his spare time, he studies acting; and in 1995, while teaching at Cornell, he performed in a community-theater production of a Harold Pinter play. Right now he’s trying to drum up funding for a three-part public-television series on physics starring, potentially, himself. But Brian Greene isn’t just a physicist who’d like to play one on TV. At 36, he holds tenured positions in both the math and the physics departments at Columbia University, and adjunct professorships at Cornell and Duke. His specialty is string theory, the spellbinding, diabolically complicated school of physics that attempts to describe everything in the known universe from quarks to supernovas. Ed Witten, the Princeton colossus who has dominated string theory for more than a decade, believes that Greene is one of the top three or four string theorists of his generation – and string theorists are some of the brightest people on the planet. They may be the ones to finally pick up where Einstein, at the lonely and frustrated end of his career, left off: with a unified field theory of the cosmos.
Greene finally finds the Lithgow picture in a manila envelope, buried in a loose pile of family photographs. “Brian,” the inscription says. “Thank you for your equations on quantum chromodynamics. John.” Greene smiles. “It was so cool,” he says, “to hear John Lithgow talking about quark jets.”
String theory, also known as superstring theory, has been around since the late sixties, but only in 1984 did a surge of persuasive new data start forcing scientists to reckon with its claims. Suddenly, conferences were being held, MacArthur “genius” awards were being given, and a moniker was born: “the Theory of Everything.” The term still gives some physicists, including Greene, a rash.
Now the field of string theory is white-hot, luring the physics world’s bright young stars deep into the hearts of the universe’s collapsing ones. Harvard’s last two physics hires were string theorists, and breakthroughs in the discipline are eagerly reported by the mainstream press. (Last July, when a group of physicists opened a banquet with a song about string theory set to the tune of “The Macarena,” even that made the science section of the New York Times.) The attention has excited resentment and envy in some scientists, particularly those who see string theory as a fad whose charms are overblown. “Don’t tell anyone in my department this,” a Princeton graduate student confessed to me recently as he was making his way over to the math building, “but I’m a closet string theorist.”
For all that it promises, string theory has never been proved experimentally. But if what it says is correct, the basic inconsistencies of twentieth-century physics will wondrously evaporate. The theory rests on a very simple premise: that the smallest building blocks of the universe – muons, photons, gluons, and all those other particles that sound like Santa’s reindeer – are generated by the vibrations of tiny, quivering loops of string. The whole universe is made up of them, tied up with them, if you prefer, as if the cosmos were a shimmering aeolian harp.
Actually, that last image is stolen from Greene’s first book, The Elegant Universe, which will start appearing in stores next week. Publishers Weekly has already given Greene a rapturous write-up (“He possesses a remarkable gift for using the everyday to illustrate what may be going on in dimensions beyond our feeble human perception”), and Kirkus Reviews declared the book “possibly the clearest popular treatment to date of this complex subject.” W.W. Norton & Company, Greene’s publisher, hopes he can do for string theory what Stephen Jay Gould did for evolution, Stephen Hawking for black holes, and Richard Feynman for quantum electrodynamics: give science a friendly face, and make a chart-busting best-seller out of a rarefied subject.
If anyone can make string theory accessible, Greene can. All of his colleagues agree he’s a whiz at explaining things, the kind of person who can make counterintuitive concepts – like the warping of time, for example, or the curving of space – seem as normal and natural as rain. Thanks to Stephen Hawking, the public’s appetite for books about particle physics and cosmology has also swollen considerably in recent years; A Brief History of Time stayed on the best-seller list for months, even though almost no one understood a word of it.
Greene has an advantage over Hawking. The Elegant Universe is actually comprehensible. In many places, it’s even compulsively readable. Greene is funny and handy with metaphors, using such diverse examples as peach pits, insider trading, and ants on a garden hose to illuminate his basic points. Small wonder that he had at least three New York publishing houses vying for the rights to the book.
Of course, string theory won’t really have arrived – the way chaos theory did a few years ago – until Michael Crichton puts it in a novel and Jeff Goldblum starts nattering about it in Jurassic Park III. But here again, Greene may prove useful, because an appealing messenger will surely hasten the dissemination of the string gospel. In a field full of men who tend to look as if they were drawn by naughty, drunken cartoonists (the thick glasses, the wild hair, the asexual posture), Greene is a striking standout, and it’s not just because he’s attractive and wears contacts. In high school, Greene won math competitions and judo tournaments. At Harvard, he performed in musicals. At Oxford, he hung out with George Stephanopoulos.
“Physicists tend to be introverted,” says Frank Wilczek, a leading particle physicist at Princeton’s Institute for Advanced Study. “Brian’s definitely at the extroverted end of the spectrum. And the charismatic end.” He giggles. (Wilczek giggles a lot. When he first hatched the concept of the axion particle, he named it after a laundry detergent. Just for a giggle.) “Physics requires the kind of personality that’s ready to sit down for a long time and learn difficult things and do abstract calculations,” he continues. “That’s almost the polar opposite of interacting with people – and having fun.” His peers, he notes, aren’t particularly glamorous. “Physics is far removed from primal urges. It has nothing to do with sex, power, or getting fed.”
Greene probably got some of his expansiveness from his father, Alan Greene, a composer, vocal coach, and former vaudevillian. He and Brian’s mother, Rita, encouraged their children to express themselves, and it seems to have worked. “I consider lecturing a form of performance,” Brian often says, and clearly, those acting lessons have paid off.
“He has this great reputation,” says Greg Langmead, a 25-year-old graduate student in the Columbia math department. “Even among students who haven’t taken anything with him. He’s a great communicator, he’s charismatic, he’s clearly top-of-the-heap intellectually. So the fact that he has gobs of raw physical appeal on top of that – it gives him a really serious mystique.”
Yet what’s good for booksellers, readers, and students may not be good for Greene’s own career as a scientist. When he first started writing The Elegant Universe, Greene didn’t even tell most of his colleagues. “Brian wasn’t sure the community would place the same value on this kind of communication as he did,” says David Morrison, a Duke University mathematician with whom Greene did groundbreaking research. “I think he was concerned that people would think he’d left the playing field.”
It’s a realistic anxiety for theoretical physicists, who, as a rule, burn out early. Most have done their best work by 40, and some peak even sooner than that. (Einstein came up with the theory of relativity at 26.) So the question naturally arises: Why would Greene, still in his prime, squander his energies on a popular book for the muddling innumerate, particularly when there’s still so much work to be done? The Elegant Universe took two years to write, so naturally his colleagues are concerned. “I think really highly of Brian,” says Ed Witten. “But I’m glad he’s finished writing his book.” Why? He pauses. “Oh, I think maybe, perhaps, it slowed him down,” he says. “Researchwise.”
Greene says it didn’t, but there are other worries. String theory, for all its hype, is still a young discipline. Some fear that if Greene’s book is a big success, it might mislead the public and lure too much talent away from other important areas of research. “I do see some danger,” admits Frank Wilczek. “People may not realize this is not yet an established theory, and also …” He trails off. “You know what Gresham’s law is, right? That bad currency drives out the good? One thing science doesn’t need is to be turned into mysticism. So I can only hope that Brian did a good job.”
On the ninth floor of the Pupin Building, at the north end of the Columbia campus, Greene is standing outside his locked office door, sifting through a Ziploc bag full of loose keys. There must be 30 or 40 of them, all of nearly identical shape and size. He broke his key chain a few months ago and has been toting around this clanking bundle ever since.
“I don’t think it’s here.”
He checks a few pouches of his shoulder bag. He reinspects the Ziploc bag. Then he checks his pocket. Eureka.
Greene’s failure to do the obvious – buy a new key chain – is one of the ways that he does conform to the stereotype of the befuddled, I’m-too-distracted-to-tuck-in-my-shirt kind of physicist, the kind who floats through life in a vapor of deep thoughts. Another is that he can’t seem to remember names and numbers, including the room number of his second office in Columbia’s math department. Ellen Archer, his girlfriend (she’s an actress, naturally), says that sometimes while he’s driving, she’ll notice that the car has suddenly slowed to a crawl, so lost is he in the caverns of his own mind. She remembers leaving him alone once at a party with one of her overtalkative friends. An hour later she found him in the same place, her friend still gabbling and burbling away like an open wound. “I’m so sorry to have stranded you,” she told Greene after rescuing him. “It’s okay,” he told her. “I was solving equations.”
Greene throws open the door, and we step into his office. The place is a disaster. There are carpet swatches and paint samples sitting on a broken chair, and big, white blotches of spackle polka-dot the walls. Inexplicably, a psychiatrist’s couch sits off to the right. The place has been under renovation for two years.
Greene readily admits that he has always been a slob. His senior year, the Harvard yearbook ran a photo of his room as the supreme exemplar of undergraduate slumminess. “When you have this sense,” he tries to explain, “that at rock bottom, there is a coherence, a simplicity, an explanatory core to the universe, I don’t know, perhaps it gives you a certain license …” He stops. “Okay. Maybe I’m just trying to rationalize not putting my clothes in the hamper.”
By age 5, Greene was already a typical prodigy, multiplying 30-digit numbers by 30-digit numbers on huge pieces of construction paper he’d taped together to accommodate his scrawling. His sixth-grade teacher (at I.S. 44, on the Upper West Side) sent him to Columbia with a note to the math department imploring someone, anyone, to please take him on and make use of his talents. At Stuyvesant High School, Greene was a Westinghouse finalist and won citywide math competitions four years in a row. He graduated in the top ten of his class at Harvard and won a Rhodes scholarship.
While he was at Oxford, Greene called up the man who would later become his postdoctoral adviser and politely pointed out an error in a paper he’d just published. (“I was surprised, then very impressed,” says Shing-Tung Yau, the humbled professor.) At 30, Greene received a Young Investigator’s Award from the National Science Foundation, and one year later, he won an Alfred P. Sloan Foundation fellowship. By then he was teaching in the Cornell physics department; and at 34, he was recruited by Columbia.
Columbia wanted Greene because both the math and the physics departments decided they needed a leading figure in string theory. (Because it is so intensely theoretical, string theory requires as much sophistication in math as it does in physics.) Greene, a switch-hitter, filled the bill perfectly. The university sweetened the deal with the prospect of letting him build his own small string-theory fiefdom, fortified by bright young graduate students and additional faculty.
Greene’s legacy may amount to even more than a fiefdom; it could be a modest empire. He and several colleagues just received a $2.5 million grant from the National Science Foundation to restructure high-level courses in the Columbia math department, with the hope of broadening their application to physics.
Greene is making his way over to Room 831, where he teaches a quantum-field-theory class to students at both Columbia and Duke, with an assist from a video-teleconferencing hookup. He’s late. On the way there, he runs into Samuel Devons, a stooped gray eminence with squinty eyes, a cane, and a long beard. Devons looks at Greene once, twice, then three times before recognizing him. “Oh,” he finally says. “It’s you! Hello.” The two men chat briefly, then Greene hurries on to his class. “He’s a real deep thinker,” Greene explains.
In the classroom, there’s a huge television monitor attached to a video camera sitting at the front of the room. Onscreen, he can see the grainy image of a professor and a couple of students waiting at Duke. Greene slings a microphone around his neck, steps in front of the TV, and waves hello to the people in Durham. “You’re late,” one of the grainy faces scolds. “I know,” Greene replies. “But everyone’s so late to this class. I guess I got lax.” He hoists his foot up onto the table and starts tying his shoe. Meanwhile, his Columbia students are still trickling in. Almost all of them are men. Almost all of them wear T-shirts and flannel. Almost all of them have astonishing amounts of hair. Before long, the room is practically full.
“Greene is a messianic teacher,” says Norman Christ, the chairman of the Columbia physics department. “When he teaches, as many people who can fit in the room will be there.”
Students adore him. He makes physics funny, they gush, and he explains complicated ideas with diamond clarity. He also knows how to make people relax. “Sometimes,” recalls Shani Offen, one of Greene’s former students, “he would throw out questions in the middle of his lectures, like ‘So then we add two and two and we get … Anyone?’ “
Greene chats casually with a student at Duke for a few more minutes (“So, Chris, how’s the Higgs mechanism?”) before gazing up and asking if anyone has any questions. Silence. “Uh, is anybody here?” he asks. Smiles. Then he’s off to the chalkboard, scribbling furiously, until he has completely surrounded himself with a confetti halo of numbers and Greek superscripts.
Brian Greene first heard about string theory on a bitter, blustery day in 1985. Walking by Blackwell’s, a famous bookstore near the Oxford campus, he spotted a flyer for a lecture on “The Theory of Everything.” He went. He saw. He was immediately conquered, though he has a hard time articulating why. The best he can do is invoke an even earlier memory of a subway ride he took when he was a teenager.
“I was feeling that way that adolescents sometimes get,” he recalls. “You know – ‘What does it all mean? What is life all about?’ The usual questions. And I remember thinking, ‘Well, people have thought about these issues for ages, and it’s not likely that I’m going to have any answers.’ But it did occur to me that if I was able to get a thorough familiarity of what the questions actually were – how is it that there are stars and galaxies and planets and people? – I would get a certain kind of satisfaction.”
String theory reconciles two previously incompatible tenets of twentieth-century physics: the theory of general relativity (which describes the behavior of very large things, like the steady outward streaming of the galaxies) and quantum mechanics (which describes very small things, like the flighty path of an electron). The former supposes that space is gently curving; the latter implies that space is jittery and unpredictable. String theory modifies Einstein’s theory in just such a way that these two conceptions of space are brought into alignment.
During the past five years, string theorists have made exhilarating strides. They posit some pretty wild notions, including the existence of eleven dimensions, a concept that Greene very clearly and engagingly explains in The Elegant Universe. Even as far back as the seventies, physicists knew that string theory predicted gravity – without relying on the theories of Einstein or Newton – proving, to some skeptics, that string theory was at least on the right track.
Greene made his first major contribution eight years ago, when he discovered with Ronen Plesser, now a physicist at Duke, that for every possible shape of the cosmos, there is a “mirror shape” that generates an alternate universe with exactly the same properties. Then, in 1993, while he was working at the Institute for Advanced Study, he and colleagues Paul Aspinwall and David Morrison made another breakthrough. After months of handwritten calculations, they realized that the fabric of space can tear, meaning the universe can change shape by ripping itself apart and coming back together again in a completely different form – a far more exotic contortion of space than Einstein had ever dreamed. When their computer spit out the final result they were hoping for, Greene shot out of his chair and started running around the room. “You know, like the guys who score a touchdown,” he says. “They spike the ball, they flip over backwards, they do a little victory dance.”
At the moment, Greene is working with several colleagues on a notion that not only overthrows conventional wisdom but plays pixie tricks with your head. They are postulating that space and time, concepts we take for granted as irrefutable aspects of everyday life, are in fact only vague approximations. Space, they think, only seems like space to us. And time, they think, only feels like time to us. But if human beings were smaller, they’d see that space and time were merely the perceivable facets of a much more nuanced series of organizing principles – the same way that crude patterns are the only thing one sees, at first, when thumbing through the pages of a Magic Eye book. “So if we were born not 20 inches long, but 10-to-the-minus-33 inches long – that’s a billionth of a trillionth of a trillionth of an inch – then we would know what those organizing principles were,” says Greene. “They would be of second nature to us, just like time and space.”
Not surprisingly, string theory still has some high-profile and well-respected detractors. Sheldon Glashow, a Nobel Prize-winning particle physicist at Harvard, was once so virulently skeptical that he questioned whether string theorists should even “be paid by physics departments and allowed to pervert impressionable students.” Today, he has softened his views, primarily because he thinks string theorists have become humbler. But he’s still skeptical. “String theory’s biggest prediction is that gravity exists,” he says. “That’s good. That’s a lot more than preceding theories could do. But it’s not enough … I mean … there. I just proved it, too. I just dropped a pencil.”
He has a point. Perhaps never in the history of physics has theory been so far ahead of experiment. String theorists, by and large, tend to be the kinds of fellows who scribble calculations on the backs of envelopes rather than the kinds who smash atoms. “I suppose I’m worried,” says Glashow, “that someday there will be some exciting experiments to do, and there won’t be anyone around who knows what experiments are.”
A number of preeminent physicists share this concern. But most still believe that string theory is the wave of the future. So to speak. “I see all the things that are wrong with the present situation,” says Steven Weinberg, a Nobel-laureate physicist at the University of Texas, “but I still think string theory is the only game in town.”
String theorists are very excited about Greene’s book, for both selfish and civic-minded reasons. Stoking the public’s romance with science is extremely important to them – particularly after Congress canceled funding for the world’s largest underground supercollider in Waxahachie, Texas, which would have enabled scientists to come as close as they ever have to understanding the Big Bang.
“In the old days,” explains Michio Kaku, a high-energy-particle physicist at CUNY, “when we wanted money, we’d go to Congress and say one word: Russia. They’d just open up their checkbooks and say, ‘How much?’ Now, for the first time in our lives, we physicists have to sing for our supper. But most scientists cannot speak the language of the land. They’re bumblers when it comes to the English language.”
A few good books, he thinks, plus a few eloquent popularizers, would go a long way toward putting food on the table. “Just as we’re so close to the finish line,” he sighs, “it’d be a crime if the public turned away from funding basic science.”
Greene couldn’t agree more. He talks about the need for the public to know what scientists are up to; he talks about providing a service to his fellow string theorists, who don’t always have time to explain their exciting progress. But the most compelling explanations he gives for writing The Elegant Universe have nothing to do with the obligations he feels toward his profession or other scientists. They’re personal.
“You know,” he says, “I don’t think physicists will ever give answers to true questions of meaning. But I do think that when one understands how the universe works on the deepest possible level, you understand questions of meaning with a previously unattainable clarity.”
Greene has no plans to write another book. The Elegant Universe took a long time, and he says he’s eager to pour all of his energy back into research. But there’s always the tug of the world on the other side of the ivory tower, that same impulse that lured him out of his classroom four years ago to perform in Pinter’s Betrayal, a bit of moonlighting he never told his colleagues or students about. (They would have liked it, too, since in Pinter’s play, which starts with the final scene, time moves backward.) In May, true to form, he’s doing a public lecture at the Guggenheim called “Strings and Strings,” which makes use of an actual string quartet to metaphorically illustrate the principles of string theory.
“Doing only the technical stuff has never seemed to me to be enough,” he admits. “Maybe because the breakthroughs don’t happen sufficiently frequently, or maybe not. But there has always been a part of me that wanted to engage with the world on a different level.” Greene smiles. “I guess,” he says, “I like having a double life.”