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# News from ICTP 85 - Commentary

*Rod Serling, creator of The Twilight Zone, spoke of a fifth
dimension--imagination. Today, string theorists speak of 11 dimensions.
If the latter's theories prove correct, our view of the physical
universe will be altered in ways that only the likes of Rod Serling
could imagine.*

**The Spirit of the Strings**

**"There are times when mathematical beauty should take
priority over agreement with experiment, Nobel Laureate Paul A.M.
Dirac observed many decades ago."**

**I**t is only fitting that the awarding
of the ICTP Dirac Medal, which is named in his honour, should
reflect the sentiments found in this statement. Since 1985, the
medal has been given each year to noted theoretical physicists
and mathematicians. Many of the winners have made their mark in
string theory--a relatively new area of research that has been
largely driven by the "beauty" of mathematical calculations.
Indeed, ICTP's Director, Miguel Virasoro helped to launch the
study of string theory some 25 years ago when he devised a number
of inter-related math equations that ultimately bore his name:
Virasoro algebra.

Mathematical elegance is one factor that has made string theory such a unique area of inquiry for physicists. In the past, the frontiers of physics were driven largely by abstract perceptions: the ability of the world's most renowned physicists--from Newton to Einstein--to see elements of the physical world that no one else could. Equations and experimentation came later, either confirming or denying the theories that had been proposed.

The study of string theory has turned this conventional thought process on its head. String theory's initial goal was to explain the concept of duality in strong interactions. The real excitement, however, came when scientists realized that string theory provided the only consistent way to unify the two great discoveries of physics in the 20th centuryEinstein's theory of gravitation and quantum mechanics. This unification, in turn, revealed the elegant mathematical structure behind the theory.

As a result, string theory--born from a desire to more clearly explain our physical universe--has been largely driven by mathematics. And that's likely to remain the case in the decades in the decades ahead. As Edward Witten, the world-renowned Princeton physicist and 1985 winner of the Dirac Medal, wryly notes: "String theory requires applying bizarre math to physics."

The second aspect of string theory that has excited physicists around the globe is the continual element of surprise that accompanies the research. "We will be looking for one thing and the math will lead us in an entirely new direction. String theory seems to have a mind of its own and scientists are often left in the position of letting the math speak for itself," says Peter Goddard, Master of St. John's College at the University of Cambridge who with David Olive, a physicist at the University of Wales, shared the 1997 Dirac Medal.

What are we to make of this new theory of the strings that is driven by "bizarre" math and follows an "unpredictable logic" of its own? What difference does it make if the atoms of our physical world consist of loops instead of dots or if we live in 11 dimensions instead of four, especially if seven of those dimensions are so compacted that they remain completely removed from observable reality?

The simple answer would be this: Virtually every fundamental breakthrough in theoretical physics has ultimately found its way into applications that have changed the world. Einstein's theory of relativity helped unlock the keys to nuclear energy. Quantum physics led to the development of semiconductors and lasers.

But to tout theoretical physics' practical impacts is to do it an injustice. Mind-bending breakthroughs in theoretical physics have forever altered the way we view our world-and that has had untold effects on how we lead our lives and think of our place in the universe. At its highest order of thought, the pursuit of theoretical physics touches the core of our beliefs, which may be precisely what makes the study of string theory worthwhile.