I'm madder than a quark that's been mistaken for a lepton by the strong force! What's got my neutrinos in a bind? The backlash against string theory, that's what. Not that I have any attachment to this theoretical hocus pocus, but I'm going to be pretty steamed if what was supposedly the dominant physical theory of the last two decades turns out to be as short-lived as a 12-minute neutron. Over the years I've read at least a dozen articles hatin' on string theory and lamenting that you can't have a career in physics unless you subscribe to it. And I've read exactly zero articles claiming that string theory is just jake. Maybe that's just selection bias on my part, but I'm beginning to think this is one of these so-popular-nobody-likes-it things, like the way serial music supposedly dominates all musical composition.
With the double publication of Peter Woit's Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law and Lee Smolin's The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next, we seem to have reached a turning point for the theory of vibrating strings harmonizing the g-forces of the universe (or is it g-strings harmonizing the vibrators of the multiverse?). But this is a backlash that's been bulding up strong force for some time. Slate, a regular anti-string theory clearinghouse, has been covering the problems with the theory for years. Case Western Physics chairman Lawrence M. Krauss has been talking smack about string theory, and he can expand for half-hours about what a mathematically ingenious dead end it is.
What does it all mean? I never understood the concept in the first place, and passages like this one from Jim Holt's recent string-cutting don't inspire confidence:
At the latest count, the number of string theories is estimated to be something like one followed by five hundred zeros. "Why not just take this situation as a reductio ad absurdum?" Smolin asks. But some string theorists are unabashed: each member of this vast ensemble of alternative theories, they observe, describes a different possible universe, one with its own "local weather" and history. What if all these possible universes actually exist? Perhaps every one of them bubbled into being just as our universe did. (Physicists who believe in such a "multiverse" sometimes picture it as a cosmic champagne glass frothing with universe-bubbles.) Most of these universes will not be biofriendly, but a few will have precisely the right conditions for the emergence of intelligent life-forms like us. The fact that our universe appears to be fine-tuned to engender life is not a matter of luck. Rather, it is a consequence of the "anthropic principle": if our universe weren't the way it is, we wouldn't be here to observe it. Partisans of the anthropic principle say that it can be used to weed out all the versions of string theory that are incompatible with our existence, and so rescue string theory from the problem of non-uniqueness.
Copernicus may have dislodged man from the center of the universe, but the anthropic principle seems to restore him to that privileged position. Many physicists despise it; one has depicted it as a "virus" infecting the minds of his fellow-theorists.
I'm opposed to anything that increases man's importance in the universe, but there's one aspect of string theory that I'll be sorry to lose: the many universes. This one obviously sucks, but it was always nice to think there might be a better model out there (up there? over there? in there?) somewhere. What I'll regret most is that one of these egghead ideas will die out before I ever had a clue what it was about, undoubtedly to be replaced by another egghead theory I can't figure out. Hey, you knucklehead experimental physicists! Do some explaining. Is string theory out? Was it ever in? Does it matter?