Why do we exist? Don't look to the stubborn string theorists

From: http://www.oregonlive.com

November 05, 2006

f you recall nothing else from Stephen Hawking's 1988 blockbuster "A Brief History of Time," you are likely to remember the inspiring final passage: "If we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason -- for then we would truly know the mind of God."

This is perhaps the most eloquent statement ever voiced of the fundamental credo of physics: that there exists an elegant final theory which, properly understood, would explain every aspect of physical reality. That final theory, physicists like to dream, would be not only elegant but unique -- no possible variation in its formulae would be conceivable.

This mythical beast -- the perfect and beautiful ultimate theory -- has proven as elusive as a unicorn. For the last several decades the quest to uncover a final theory has been dominated by string theorists, who are attempting to reconcile relativity (which provides a superb description of nature at macroscopic scales) with quantum physics (which offers an uncannily accurate explanation of the behavior of matter at the smallest scales).

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The essential claim of string theory is that what we perceive as electrons, photons and other sub-atomic particles are actually tiny one-dimensional snippets of energy vibrating furiously in 11 dimensions. The theory seemed, at first, to offer a promising path forward toward the goal of seamlessly melding relativity and quantum mechanics because it overcame mathematical problems that had dogged earlier efforts at reconciliation. Sadly, reality has turned out to be at odds with the dreams of string theorists.

For starters, there seems to be no possible way to test string theory experimentally. As Columbia University mathematician Peter Woit puts it in "Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law": "From the beginning, there was both no experimental evidence for superstrings and various obvious problems in the way of ever being able to use them to make experimental predictions."

More ominously, out of the deep mathematical recesses of the theory has emerged something called "the landscape," which is essentially a collection of alternate theoretical universes, most of which bear no resemblance to the one we inhabit. Far from predicting uniquely the seemingly arbitrary parameters and constants of physics we observe in our cosmos, the landscape of string theory offers -- like Alice's restaurant -- just about any cosmos you could possibly want. This should alert us, Woit warns, that string theory is not really science but a field of pure speculation resembling metaphysics and theology.

Cosmologist Lee Smolin covers much of the same ground in "The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next." Smolin's book, though, offers an essential supplement to Woit's searing critique by revealing something nonscientists may find surprising: the crucial importance of variation in the styles of scientific thinking. For instance, the contemplative, almost philosophical scientific style of the great scientific visionaries of the 20th century (Einstein, the inventors of quantum theory and their illustrious disciples) differs dramatically from that favored by the particle theory community, which is brashly competitive, disdainful of deep theorizing and intensely reliant on experimental results. String theory research, Smolin notes, grew out of particle physics research -- a branch of the scientific culture that has been historically hostile to exploration of the very foundational issues string theory now haplessly confronts.

Another factor that disturbs Smolin is the sheer arrogance of string theorists, even in the face of their abject failure to generate falsifiable experimental predictions or to come up with a unique theoretical solution.

Both "Not Even Wrong" and "The Trouble With Physics" reveal that a disturbing pathology has infested a critically important field of scientific research. That pathology consists of an irrational unwillingness on the part of a dominant faction of physicists to even consider alternative pathways to the mountaintop of which Hawking dreamed -- a true and beautiful final theory.

James N. Gardner is an Oregon attorney and the author of "Biocosm" and "The Intelligent Universe: AI, ET, and the Emerging Mind of the Cosmos" (coming in 2007).