You know things are getting strange when Esquire magazine starts running an article on the current state of particle theory. As you might expect, their take on this is rather odd. It centers around Nima Arkani-Hamed and begins with:
For a hundred years, physicists have been scraping away at the strange and complicated phenomena obscuring the true face of our universe. Finally, a few brillant young thinkers may be on the verge of getting the first real glimpse.
which is pretty much complete nonsense, totally ignoring the huge success of the standard model in favor of the latest extremely speculative models promoted by some people.
The Esquire writer talked to several theorists, including Lee Smolin and Laurent Freidel at Perimeter, where he describes young postdocs as hanging out at a local hipster bar, with one of their number describing string theorists as “the post 9/11 theocons”, afraid of anything new: “The string theorists just masturbate to their same ideas.” The postdocs do note that at Perimeter string theorists and non-string theorists get along fine. Freidel, a faculty member at Perimeter, is described as not having slept for two weeks straight when he was working on a solution of QCD, with his wife asking a colleague “Can you do something? He’s going insane.”
After describing Perimeter, the article then moves on to Witten and Maldacena at the Institute in Princeton. Witten’s comments about the current state of things go as follows:
Well, you can’t have your best year every year… I’ve lived through two periods, the mid-eighties and mid-nineties, where for about six or seven years, roughly, there were a lot of really interesting results that were also relatively easy. And I’ve also lived through several periods by now where you have to work a little harder to get something interesting.
Witten goes on to say that he is putting his hopes in the LHC and the idea that it is likely to tell us something about the nature of electroweak symmetry breaking.
There’s some attempt to describe Maldacena and his AdS/CFT conjecture, which is characterized as “a mind fuck, but not crazy.” The article then moves back to Arkani-Hamed at Harvard, with “For crazy, you have to go about 250 miles north.” His view of the current controversy over string theory is said to be “forget the antistring polemicists! They’re just reactionaries! This could be the greatest discovery of our time!”, and he heavily promotes the anthropic landscape and the idea that the LHC will provide evidence for it. He says:
The mantra of string theory ten years ago was that the theory was smarter than you… Well, exactly that–just follow the theory where it leads you and it leads to this precipice. And now we have to decide what to do. So now a number of people are deciding to jump… And I think that those of us that decided to take the plunge are staring at the true nature of the beast for the first time.
Personally, I think if a scientific theory with no experimental evidence for it takes you to the edge of a precipice and tells you to jump, the sensible thing to do is to say “No Thanks!”, back away, and go find another theory. But that’s just me.
The latest New Scientist also has something about the string theory controversy, an article by Michio Kaku entitled Will we ever have a theory of everything?, part of a series of articles on “The Big Questions”. Kaku describes the controversy dramatically:
It’s all-out war. The hostilities have begun. With guns blazing, daily salvos are being fired by both sides. Welcome to the conflict raging within the rarefied world of theoretical physics, where a civil war has erupted over string theory and a theory of everything.
While I disagree with the far too rosy picture he paints of the prospects for string theory, Kaku takes a very sensible attitude towards the whole thing:
So who’s right? Actually, both have a legitimate point of view. But far from signalling a collapse in physics, this debate is actually rather healthy. It’s a sign of the vitality of theoretical physics that people are so passionate about the outcome. Science flourishes with controversy.
and ends, reasonably enough with:
One day, some bright, enterprising physicist, perhaps inspired by this article, will complete the theory, open the doorway, and use the power of pure thought to determine if string theory is a theory of everything, anything, or nothing.
New Scientist also asked various well-known physicists what they thought might happen in physics in the next 50 years. Weinberg says that he hopes for a final theory of particle physics, with discovery of superpartners a first step. Tegmark also hopes for a final theory, one which will have us living in just one of many “parallel universes”. ‘t Hooft hopes for a deterministic model that would unify quantum mechanics and gravity, Randall for a new understanding of space and time, Carroll for a theory of the big bang, Wilczek for a new golden age of particle physics catalyzed by the LHC, Kolb for the discovery of gravitational waves and Vilenkin for the discovery of a cosmic string. The most popular question on many these people’s minds is that of whether or not we live in a multiverse (Tegmark, Rees, Krauss mention this). Among mathematicians, Marcus du Sautoy suggests we’ll have a proof of the Riemann hypothesis, Timothy Gowers favors P=NP.
Among all these and other scientists, I think the most plausible prediction comes from my graduate school roommate, Nathan Myhrvold, who thinks a revolution will come from materials science, with the development of new “metamaterials”, substances with new, intricate synthetic structures.
Update: Somehow I hadn’t noticed that New Scientist also had a prediction from Witten:
String theory will continue to be an extremely fertile source of new ideas. It will still be viewed as the interesting candidate for quantum gravity, and may even be more or less understood by 2056.
Interesting that he thinks that 50 years from now the situation will be much the same, with string theory still just a “candidate” for quantum gravity, and he doesn’t predict that we will have string-based unification of particle physics and gravity.