World On A String
PHOTO: SYLVIA OTTE
Brian Greene Brings Physics & String Theory to the Masses
|Brian Greene is not the only
physicist working on a master equation of the universe, but right
now he is the most popular.
The dashing 37-year-old Columbia math and physics professor is bucking the stereotypes of brilliant but disheveled scientists who would get much more attention if only we could understand what they were talking about.
Greene cracks jokes in the classroom, goes out dressed in New York black chic, takes acting classes and sticks to a vegan diet. He was a student-athlete at Harvard and a Rhodes Scholar at Oxford.
Now, with the publication of his book, The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory (W.W. Norton & Company, $27.95), and the publicity that has accompanied it, he is luring lay people into learning about cutting-edge physics with his engaging prose and soothing, late night radio host voice.
"Brian Greene has a real skill for taking complex and arcane topics and making them accessible and understandable to a variety of audiences, even other physics faculty when we have the opportunity to quiz him," says Norman Christ, chairman of the physics department.
It sounds obscure, but it could be incredibly important to understanding the world: how it started, what it is made of, and why it acts the way it does. Greene and a growing group of the world's leading physicists think that everything essentially is made up of tiny vibrating strings.
String theory is therefore dubbed a "theory of everything" and could be the biggest breakthrough since Einstein's work. It has also been called "the final theory," even though some physicists question whether it has any validity at all.
"Why go to
The theory is relatively young. Its origins are in the '60s, but it has made its greatest advances following a mathematical breakthrough in 1995. Greene lays it out for the masses in The Elegant Universe, a physics book for a general audience that has been compared to Stephen Hawking's A Brief History of Time, except that it is more accessible and entertaining.
"People can be turned off from science, because the technical side can be forbidding, but the ideas are as dramatic as any novel," Greene says in his airy Riverside Drive apartment. "Why go to fiction all the time? Why not use real science? Extra dimensions, space tearing, that's wild stuff!"
And people are interested. The Elegant Universe went into three printings in its first month of publication. It has been on bestseller lists nationwide, getting up to No. 17 on The New York Times list and outpacing even John Grisham's new novel to hit No. 1 on Amazon.com. Book signings have overflowed, interview requests abound, admiring readers pepper Greene with e-mails and armchair physicists stop him regularly on the streets of Manhattan.
In May, the Guggenheim Museum in New York held an event featuring Greene explaining the basics of string theory alongside performances by the Emerson String Quartet. "Strings and Strings," as it was called, was so popular that a crowd was left out on Fifth Avenue scratching at the museum's door for standby tickets. (Due to the demand, an encore performance has since been scheduled for December.)
Those inside were treated to a crash course in basic physics and string theory, illustrated by amusing graphics and anecdotes, and kept engaged by Greene's easygoing speaking style. Explaining Einstein's theory of relativity, he says, "We're used to always being able to go faster -- hit the accelerator, hop on a Lear jet, ride the space shuttle -- but Einstein said that there is a universal speed limit." He describes Heisenberg's uncertainty principle as "like ordering from a Chinese menu. There's list A and list B. You can have Chow Mein, you can have Mu Shu, but under no circumstances, according to Heisenberg, can you have both."
String theory says that the smallest and most basic unit of all matter is not an atom, electron, quark or any other particle, but a little loop of string.
"That means that the ink Shakespeare used to pen King Lear, the rings around Saturn, the subway you may take home, the bed you will sleep on and the dreams you dream there -- everything is made from string," Greene tells the Guggenheim audience, using notes but no script. The strings are in the form of tiny, vibrating loops of energy. All the different types of particles and forces are made of these strings, simply vibrating in different ways.
That is, if they actually exist. They are so small that there is no way to see them or to experiment with them. If an atom were the size of the known universe, a string would be the size of a tree. Strings may be the answer to "How small can you go?" They are made up of nothing else and cannot be divided. "It may be the end of the line," Greene says. String theorists believe they exist because mathematical equations point to them.
theory may be the theory that with one idea, one master
"You may ask, 'Strings are so small, should we even worry about them?'" he says. Then he equates them to the Holy Grail of physics -- the key to figuring out how the universe really works. String theory comes into play when the very huge and heavy meet the very tiny, which is rare but could explain such phenomena as the Big Bang and black holes.
So far, physics has solved problems using general relativity, the rules that govern very big and heavy things like, say, galaxies, and quantum mechanics, which explains what goes on with very tiny things, like subatomic particles. But these two theories are contradictory when you try to use them together. For example, on miniscule levels -- ultra-sub-atomic distances -- the terrain gets wild and wacky and unpredictable. It breaks down into what physicists call "quantum foam."
Einstein spent the rest of his life after general relativity trying to figure this out, but couldn't. "String theory may be the theory that with one idea, one master equation, can explain everything in the universe," Greene says.
String theory also says that the fabric of space can rip, an important discovery made by Greene and a colleague a few years ago, and that there are more than three space dimensions -- perhaps as many as 10.
In the Guggenheim's auditorium, Greene introduces the concept of extra dimensions using a projected image of a plane, looking like graph paper, with spheres sitting on it. "Now imagine this," Greene says. In one of the professor's prize animations, along comes an ant, which skitters across the plane, then loops around a sphere.
Greene acknowledges natural skepticism by wryly joking, "You may say, 'There may be a civilization of green people down there, and we can't see them, either.'" He pauses for effect. "Yes. That is one of the other theories of string theory." The audience doesn't laugh until he calmly adds, "Well, no, not quite."
His book follows the same lines, with Greene anticipating questions -- "Why strings? Why not little frisbee discs? Or microscopic blob-like nuggets?" -- and talking readers through each concept using examples like spaceship races, a peace treaty being signed on a speeding train and brothers testing their car at a racetrack.
"I just want to have an impact on the deepest questions people have ever asked," Greene says of writing the book. Theories, he says, "should be shared beyond the few who have access to the technical details." A colleague of his was riding an airplane this spring and overheard two young people talking about string theory. He saw that they had Greene's book with them and later told Greene, "It's so great that there's this little buzz about string theory!" That delights Greene, too. "I told myself if this reaches one young kid and turns him or her on to these ideas and they become part of a research team, that would be satisfying enough for me," he says.
Judging by his e-mail inbox, he has succeeded. An undergraduate student studying physics wrote to Greene that she had been given The Elegant Universe as a gift. "Not only was it concise, readable, and understandable, but also amusingly quirky," she wrote. "Your ability to capture the inherent
pleasure in theoretical physics was inspirational for someone hoping to someday join your ranks." He has received kudos from other students, professors, and a wide array of miscellaneous professionals, such as one man who described himself as "a playwright and independent filmmaker who got a D in high school physics." He wrote, "You have given science back to me, and for that, I owe you an immeasurable gratitude."
Brian Greene himself was exceptional as a child. At age 6 he taped sheets of construction paper together, not for an art project like most kids but instead to multiply 30-digit numbers, a feat he downplays now. "It's a weird thing, mathematics," he says. "Even as a 6-year-old you can learn a few rules and then play around with it. You can't do that with literature, where you need years of experience to say anything interesting."
By the time he was in sixth grade he had exhausted the curriculum at his public school, IS 44 on Manhattan's West Side. His teacher sent him to Columbia with a letter of introduction to the effect of, "We've done all we can here. Somebody please take this boy on." Greene and his sister went up to campus and walked door to door handing people the note. Finally they found a graduate student who was willing to tutor him (as a volunteer). The two met weekly for years until Greene went off to Harvard.
Despite being gifted, the young Greene was far from a nerd. He competed in wrestling in high school. At Harvard he ran on the cross-country team and acted in musicals. He then went to Oxford on a Rhodes Scholarship, where he joined an improv theater group and where one of his friends and jogging partners was George Stephanopoulos '82.
He went to Oxford to study gravity and quantum mechanics, planning to become an academic. Walking home one winter day he saw a poster for a lecture explaining a new-found "theory of everything." "It made it sound dramatic," Greene says. He went and heard Michael Green, then of Queen Mary College, talk about his work on string theory with John Schwarz of the California Institute of Technology. "I found it very exciting. They were saying there was a brand new way to solve the riddle of gravity and quantum mechanics," he says. He and two friends decided to delve into the topic and started cram sessions on their own. They found relevant papers and assigned themselves reading, then met to work through the materials together.
Since then, Greene has become one of the world's leading string theorists. He taught at Cornell before Columbia recruited him in 1996 for a dual appointment with tenure in the math and physics departments, and he continues teaching at Cornell and Duke by videoconferencing.
His classes, both undergraduate and graduate, are high level but in demand. "He makes little jokes to keep us awake, and he won't say things in the most souped up language he can think of," says Greg Langmead, a mathematics graduate student who in May completed Greene's two-year class on quantum field theory. "He breaks things down in the most basic language. It makes it engaging and enjoyable, which is why we've been hanging on for so long even though the concepts are fuzzy."
"I can't imagine feeling worse than coming home realizing you've bored people for the last hour in class," Greene says.
"If this reaches one kid and turns him or her on to these ideas... that would be satisfying enough for me."
Inspired by reading The Elegant Universe, some people who have no connection to Columbia or to physics have shown up wanting to sit in on his class (he explains to them that the class is at a much more advanced level than the book).
He is thinking about teaching an undergraduate-level physics for poets type class based on the book, and is exploring other ways to make science palatable for the general population. He contributed to a panel discussion trying to inspire filmmakers to produce films on scientific topics, and he has helped authenticate some of the physics-speak on the television series 3rd Rock from the Sun.
There is arguably no better spokesperson for physics than Greene, who combines charisma with performance skills honed in acting classes. He acted in Harold Pinter's play Betrayal while in Ithaca, and continues studying acting in New York. "It's a release, a way to enter a new world," he says. "The things you think about are totally different from what you think of in a normal research day. Issues of human character and genuine human response are at the other end of the universe from trying to figure out why this string vibrates this way or that."
String theory is seen as an exciting and promising field, and many of the most talented graduate students in physics are gravitating toward it. "This is the environment in which things get done -- an enormous sense of fertility and promise to see new things invented," Norman Christ of the physics department says. But that bothers some academics worried about a brain drain in the rest of the field. It is especially bothersome since what the theory can accomplish is debatable.
"We haven't seen a single thing from string theory actually happen," Greene admits. "The theoretical tools are way ahead of the experimental ones."
Most of string theory work is done on chalk boards and computers working with complex equations. No experiments can be done on strings, since they are too small to probe yet, or to be sure they are there at all.
But even skeptics are keeping tabs on advances. "String theory doesn't say much about the observable world. It doesn't make any predictions that can be verified by experiment," says Sheldon Glashow, a physics professor at Harvard and a Nobel laureate. "Still, there is a host of questions left wide open that have to be answered by some theory, and the hope is that it will be string theory, because there's nothing else on the horizon as far as I can tell."
A machine is being built in Geneva to test supersymmetry, which could become the first part of string theory to be proven by experiment. The rest of it is in the form of mathematical models for now, and part of what Greene and others are working on is coming up with ways to test them.
"You can find yourself momentarily gripped with fear that you're spending a working lifetime on something and in the end still couldn't know if it's right or wrong," Greene says. "But there's never been a theory in physics that has gotten remotely as far as this one has and has turned out to be wrong."
Shira J. Boss '93 is a contributing writer for CCT who profiled Brian Dennehy '60 and Roone Arledge '52 in recent issues.