String Theorists Hunt for the `Theory of Everything'

Albert Einstein was, in the last years of his life, a very frustrated man. Try as he might, the scientific genius simply could not devise a unified, consistent mathematical principle to explain the physical universe. He died in 1955, still working on the same problem.

The daunting task of string theorists is to solve what the greatest scientific mind in this century could not. In their attempts, they try not to lose sight of their ultimate source of support: the public, most of whom have no idea what string theory is or purports to do.

"Society is supporting them in the adventure, and the least they can do is explain their findings to the society in a language which is comprehensible," newly tenured Harvard physics professor Cumrun Vafa says of his fellow string theorists.

The ingredients of this theory are simple--the four known forces in the universe, plus a dose of patience and a sublime grasp of higher mathematics.

In increasing order of potency, these four forces are gravity, electromagnetism, the weak force and the strong force. At higher and higher energies or temperatures, physicists predict, these forces "merge" into one, unified force.

To the dismay of scientists, no laboratory is even close to achieving such high energies. The recently-built Tevatron particle accelerator in Chicago falls short by a factor of about 10,000 trillion, or 10 with 16 zeroes following it.

Many particle physicists have set their hopes on the superconducting supercollidor, a massive government-sponsored project several years and billions of dollars from completion. But Newsweek has called the project "the biggest porkbarrel project in history," and several members of Congress are solidly against it. And even if funding is continued, the 50-mile wide apparatus will only increase attainable energy 20-fold.

So what's a string theorist to do? Rather than beg their respective governments to fund a particle accelerator stretching to the edge of the universe, physicists have taken a different tack--looking backwards in time.

At the birth of the universe, so the theory goes, all matter was condensed into a package much smaller than an electron. This package had a nearly-infinite amount of energy--enough to cause the four forces to "melt" into one symmetric force. Measuring, probing and just thinking about the present universe, scientists hope to learn about the newborn universe, and how one force somehow became four in the intervening 15 or 20 billion years.

Here is where theorists cannot help but wax poetic. Look at a middle-aged man and try to picture him as a baby--the task before string theorists is infinitely more difficult.

"The scientific theorist is not to be envied," Einstein said in a 1922 lecture. "For Nature, or more precisely experiment, is an inexorable and not very friendly judge of his work."

But not to despair: Science has made some progress towards grand unification. In 1967, Steven Weinberg and Abdus Salam managed to unify two of the forces, the electromagnetic and the weak, into one "electroweak" force. Together with Harvard's Higgins Professor of Physics Sheldon Glashow, the two won the 1979 Nobel Prize for their work.

The next step for scientists is to unify the electroweak force and gravity into a "Grand Unified Theory," and then, ultimately, combine this with the strong force to yield the modestly titled "Theory of Everything."