Monday June 29, 1998



String theory cosmic yarn 


[Image of Clifford Johnson and Finn Larsen] 


 Their scientific goals are surely among the most lofty: To come up with a Theory of Everything, as it's immodestly called. 

This all-encompassing framework would explain the most basic building blocks of matter and all the forces of nature. It would lay to rest lingering questions left by Einstein and offer a clearer understanding of the origins of the universe. 

But for the moment, crowded under a big white tent next to UCSB's Kohn Hall, more than 300 of the world's top theoretical physicists are working through the steps of ``The Macarena.'' 

One theorist blurts out an adequate rendition of the popular Latin tune on his trumpet. Scores of hands reach out. Arms cross. Hands tap the backs of heads. Then, still in unison, some of science's sharpest minds jiggle their behinds. 

Jeff Harvey, a Fermi Institute scholar from Chicago who would soon give a talk entitled ``A Few Bumps on the M5,'' shouts modified lyrics to what he renamed ``The Maldacena.'' 

Super Yang Mills 
With very large N 
Gravity on a sphere 
Flux without end 
Who says they're the same 
Holographic he contends 
Ehhhh! Maldacena! 

Three other equally cryptic verses pay whimsical tribute to Juan Maldacena, a young Harvard professor from Argentina whose insights recently sent new waves of excitement through the cerebral group. 

The dancing physicists roared as Harvey, dressed casually like almost everyone else at the catered dinner, chanted the final lines: 

The black hole we have mastered 
QCD we can compute 
Too bad the glueball spectrum 
Is still in some dispute 
Ehhhh! Maldacena! 

It was a light interlude in the heavy week of the Strings '98 Conference, an annual gathering of scientists like Maldacena who work on the frontier of physics known as string theory. The international conference was in Amsterdam last year and will be held next in Germany. 

String theory, or superstring theory, is one of those new science terms that has woven its way into the popular lexicon - like quantum and quark - but which very few people could explain. Even the participants in the conference will tell you that string theory, like much of the new science, is not an easy one to get a grip on. 

Indeed, there is a science fiction quality to the ways in which string theorists think they may be able to describe reality.``Part of string theory is that the world is not three spatial dimensions and one time dimension, which is what we see,'' says Steve Giddings, a UCSB professor of physics and a conference organizer. ``We don't exactly see them because they're very, very tiny.'' 

Giddings has blue eyes and chiseled features. A shock of brown hair hangs boyishly on his forehead. A Utah native, Giddings enjoys mountaineering when he's not exploring theoretical frontiers. He's fit and dressed as if about to embark on a day hike. 

At 36, the laid-back physicist is hardly the youngest in attendance. Many, including the feted Maldacena, are scarcely 30. Most are men, and most can execute simple dance moves. Any other generalizations would be, well, unscientific. 

To try to understand the multi-dimensional aspect of string theory, picture an ant crawling along a straw, Giddings says in between lectures during the six-day conference, which ended Saturday. The ant can walk along the straw, or go around it. But if the straw becomes exceedingly small, it would seem to the ant that it could only walk along it. Yet that other, circular dimension is still there. It's just not readily apparent. 

In string theory, there are a number of miniscule extra dimensions that, like the hypothetical ant, people just don't see. The microscopic world is not like the common-sensical world. 

 [Image of David Gross] On a more cosmic scale, string theory may also explain the beginning of the universe, and what happens inside black holes, where previous laws of physics, including Einstein's theory of general relativity, don't hold up.``The theory we're in the process of developing is a quantum theory of space and time. And that appears to be very, very bizarre,'' says David Gross, a former Princeton physicist who last year took over as director of UCSB's Institute for Theoretical Physics, the conference sponsor. 

Consider, for example, the holographic principle alluded to in ``The Maldacena'': If it's correct, then our 3-D world is really, surreptitiously, two dimensional. That everything appears to be 3-D is merely a sophisticated illusion.``There are many other very strange things that are beginning to be revealed by this theory that suggest, in the most dramatic form, our vision of space and time, which is so primary to the way we think about the world - we live in space, which we can move around in, and time flows on, right? - all of that is perhaps some kind or illusion or approximation to a way of thinking about the world,'' Gross says. 

It all sounds wonderfully perplexing, like a quintessential Mulderism lifted from an ``X-Files'' script. 

The conference itself is set up strictly for string theorists, who speak a peculiar mathematical dialect. To sit in on the lectures is to feel like the only child a dinner table of adults. You pick up bits of the conversation. Certain words stand out. You sense that something of interest, something very important, is being discussed. But you can't possibly understand what everyone's talking about.``The Maldacena'' is obviously not a song that most listeners could fully appreciate.``It's very hard to convey a lot of this, except in very broad terms, without mathematics,'' Gross says during a break at his institute office, where almost every book on the shelves seems to have the word ``strings'' in the title. 

Gross has thinning gray hair and an intensity tempered by sporadic grins that border on the mischievous. He excuses himself briefly to get a cup of black coffee. The frenzied scrawl of symbols on the blackboard in his office, across the road from placid Goleta Beach, reflect a caffeinated energy. 

He and others talk about all the excitement at the conference. ``Revolutionary'' is a word often used to describe the emerging theories. While perhaps difficult to convey, that excitement can be sensed in other ways, such as when Gross eagerly looks at his watch. It's 2 p.m. A lecture entitled ``Comments on String Theory on Anti de Sitter Space'' is about to begin. 

Gross hurriedly tosses a few things into his briefcase, including a small tin of cigars, and strides briskly toward his Acura in the nearby parking lot. The dusty sedan looks at once black and very dark blue - sort of like Schrodinger's cat, the mascot of the new physics. 

The smell of tobacco permeates the inside of the car. Protruding from the ashtray is a half-smoked cigar - ``it's pretty cheap, actually. I can't afford the really good ones,'' Gross says, puffing and grinning inscrutably as he speeds along Lagoon Road. He seems a different character from Giddings. 

Gross parks near the Lotte Lehmann Concert Hall, where most of the lectures are scheduled. The music auditorium was secured by chance for the conference, but seems an appropriate venue for a group of theoretical physicists who believe nature has perfect pitch. If only they could hear it. 

An underlying principle of string theory is that the most fundamental building blocks of the universe are not actually particles - electrons, photons, neutrinos, quarks and such. What appear to be particles, the theory goes, are actually tiny loops, little strings about a billion, billion, billion times smaller than the smallest thing you can see with your eye. Or, more precisely, a subatomic speck measuring one over 10 followed by 33 zeroes of a centimeter. 

Different motions and vibrations are what allow the strings to masquerade as the various elementary particles.``You get all the complexity and richness of the universe from these very basic, simple objects,'' Giddings says. 

At least that's the theory. No one has ever seen a string. But if strings exist, as everyone at the conference bets they do, they would go a long way toward completing the revolutions fomented by Einstein and by the quantum theorists of the 20th century.``We string theorists are not humble,'' Giddings confesses. ``We want to understand everything on a fundamental level all at once." 


Local | Sports | Business | Life | Editorial | Barney Brantingham | Weather | AP | Site Index 

Reprinted by permission.

Downloaded from: