Bob Berman: String Theory's trendy, but baseless

String Theory's trendy, but baseless
From The Woodstock Times, Thursday, August 18
http://ulsterpublishing.com/index.cfm?fuseaction=article&articleID=350699

Night Sky

Hanging by a thread
String Theory's trendy, but baseless

by Bob Berman
Science has long tried to come up with a Grand Unified Theory. It's a wonderful concept: a way to tie together all the universe's forces. Einstein struggled unsuccessfully with this most of his life, and he wasn't alone. But, listening to the PBS NOVA special or reading some self-serving books, one might conclude that the tussle is over, the goal has been achieved. Its name is String Theory.

String Theory claims that at the tiniest levels of existence, a trillionth of a trillionth the size of an electron, vibrating one-dimensional threads wiggle around, and can loop or link in various ways to produce all the universe's forces. This image is appealingly simple, but the actual theory is incredibly complex. Brilliant people are involved with it, and the rest of us may be intimidated into thinking that, like some of the old Dylan lyrics, what's incomprehensible is automatically profound.

But many physicists - including those in our region - have been shaking their heads almost from the get-go. Since we first explored this topic nearly two years ago, the pace of both advocacy and criticism has accelerated. It's time for a second visit.

Problem One is that String Theory doesn't work in our reality of three dimensions, plus one of time. To make it work, its creators had to invent seven additional dimensions, for which our own senses and the rest of science have not a shred of evidence. None of those other dimensions can possibly be tested. They have to be taken on faith.

Problem Two is that String Theory is unfalsifiable. This means that no experiment can tell if it's right or wrong.

Problem Three is that String Theory's only prediction (involving the strength of the cosmological constant) proved to be incorrect by 55 orders of magnitude. Any other theory would have been tossed out at that point.

Problem Four is that one can tweak those seven imaginary dimensions in so many ways that there IS no such single entity as "String Theory." Instead there are almost an infinite number of possible final things that you can end up with. None of them has as yet been successful on any level, except for some neat original math.

Problem Five is not so much a problem as a selling point. In the current issue of Discover magazine, ST advocate Michio Kaku argues that one factor in favor of ST is that it is "elegant." But skeptics see just the opposite: a sewer of unattractively swirling ad hoc bandages.

All this makes Columbia University physicist Peter Woit adapt an old exclamation used by Wolfgang Pauli nearly 75 years ago. In a recent issue of New Scientist, Woit says of String Theory, "It's not even wrong!" Having just discussed this subject at length with Woit last week, I feel free to say that Woit is completing a book about ST with this very title, which will be published in 2006.

We might all wonder why universities and the mass media would play with strings for so long if the theory is neither testable nor has yielded any practical results after two decades. Why would any grownup deal with imaginary things?

The partial answer is that mathematicians routinely hang out in make-believe playgrounds. Negative square roots, for example, are among many imaginary numbers that cannot exist in the real world but are mainstays in the classroom. Perhaps those who spend most of their time in such circles start confusing the real world with stuff that exists solely in the mind.

Until recently, science dealt with theories quickly and mercilessly. They'd be tested. Confirmed ones were kept; wrong ones were tossed. But this time, string theorists have managed to concoct dreamlike dimensions without having to present a shred of evidence for any of them, then argue that no testing is possible and then produce no results. Magically, this fantasy world nonetheless coasts along for decades.

Peter Woit thinks that the main reason is because it's been the only game in town, the hot-button label, the sure way for graduate students to get funding and publicity. But he wonders how much longer the media will waste its time on a perpetual, well-promoted but never-successful investigation of a theory that has no connection with the physical world.

My own prediction: In the next two years the whole ball of yarn will begin publicly to unravel - and theorists will finally start to move on.

Let's hope so. This is nonsense, and enough is enough.
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