An interesting short interview with Ed Witten in this week’s New Scientist. Mostly straightforward stuff, but it’s always good to hear what smart people are thinking. Witten is spending the year on sabbatical at CERN; like many people, he was sort of hoping to be there when the first physics results from the LHC appeared, but reality intervened an that’s looking increasingly unlikely. Happily, CERN has developed electronic means of communication whereby interesting findings may be promulgated to researchers who are not within close physical proximity to the lab.
Longtime CV readers may be interested in Witten’s take on the String Wars:
The 1980s and 90s were dotted with euphoric claims from string theorists. Then in 2006 Peter Woit of Columbia University in New York and Lee Smolin of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, published popular books taking string theory to task for its lack of testability and its dominance of the job market for physicists. Witten hasn’t read either book, and compares the “string wars” surrounding their publication – which played out largely in the media and on blogs – to the fuss caused by the 1995 book The End of Science, which argued that the era of revolutionary scientific discoveries was over. “Neither the publicity surrounding that book nor the fact that people lost interest in talking about it after a while reflected any change in the intellectual underlying climate.”
That sounds about right. For the most part, actual string theorists simply went about their business, trying to figure out what this fascinating but difficult theory really is. The irony is that a major point of the anti-string books was that the public hype concerning string theory didn’t paint an accurate picture of its more problematic features — which was true. But the backlash books gave the public a misleading impression in the other direction, leading to the somewhat amusing appearance of my own piece in New Scientist explaining that the theory was for the most part chugging along as before. Hype cuts in every direction, and it feeds on drama, not on accuracy.
There is certainly some feeling that the near-term growth area in high-energy theory is not string theory, but phenomenology (or arguably particle astrophysics). Certainly those are the people who seem to be getting the jobs these days. The explanation there is pretty straightforward: data! Or at least the promise thereof. It’s hard to do physics with little to go on other than thought experiments, but one gets by when relatively few real experiments are available. Increasingly, that’s no longer the case.
But it’s been a long time since we’ve had a good string-wars thread, so here you go. For old time’s sake.
‘The problem with your [Peter Woit] book and blog is that they do not offer any way of making progress – all they do is call for a shutdown of string theory (which as you yourself admit above, has lead to useful things). What do you recommend as a better, concrete, alternate way of making progress? Lets hear it, dammit.’ – jamie, April 13th, 2009 at 1:03 pm
‘“jamie” … If you want concrete suggestions for what to work on, note that we don’t understand the electroweak theory non-perturbatively at all. There are all sorts of questions about non-perturbative QFT that we don’t understand. Sure, these are not easy problems, but then again, all the problems in string theory are now supposed to be too hard, why not instead work on QFT problems that are too hard? Personally I’m currently fascinated by the BRST formalism.’ – Peter Woit, April 13th, 2009 at 2:49 pm
‘And about your research advice for me: don’t you think it is more prudent if I took advice from somebody who has, you know, actually made it in academia???’ – jamie, April 13th, 2009 at 4:40 pm
First Jamie asks Dr Woit for advice, Dr Woit gives the requested advice, then Jamie says he doesn’t want advice from Dr Woit! It’s funny to see rhetorical questions backfire when answered honestly. Everytime a string theorist asks what alternative ideas there are to work on (as a rhetorical question, the implicit message being ‘string theory is only game in town’, they have to be abusive to the alternative ideas they receive in reply.
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I read Not Even Wrong, and not Trouble With Physics. It was, in my opinion, not well written; and was no longer in print when ordered. Anyhow, I then found the author’s WordPress-based blog and made some comments, only to experience unsanctionable difficulty–as people have their own problems.
In reading through the comments presented here, it is obvious that I am not alone in seeking increased knowledge about BRST and Dirac Cohomology, though. 🙂 Yet, amidst plenty of separate commentary posted about “History,” there is no reason to anticipate that writing skills that would formally be displayed can rival those expected of a even a business person.
It is nearly evident that string theory has been forestalled–regardless of whether its adherents are leading anyone toward foisons.
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Sean I’d love to get your take on my post above. I think there’s a bigger cultural point to be made about the String Wars and if anyone else has made it I haven’t noticed.
I don’t know how jamie would answer, but here we go…
“What is space?”
A 3 dimensional real basis imposed by the S-dual nature of the electromagnetic field.
“What is time?”
The fourth basis imposed by the antisymmetric nature of the dominating electromagnetic interaction.
This point really needs to be hammered home. All knowledge and information we obtain and share with the rest of the universe, including knowledge of particles and other fields, is transmitted via the electromagnetic field and its gauge boson. Everything we know is derived from analysis of perturbations of the electromagnetic field we are immersed in.
The dimensionality of spacetime as we observe it is entirely dictated by the electromagnetic field, and the electromagnetic field defines the 3+1 dimension spacetime of our macroscopic experience.
It should also be pointed out that our ability to sense the fourth dimension is entirely because we are part of a large N system. If the system is only composed of a few particles, then coherent states can emerge and time becomes undiscernable.
“What is a particle?”
The standard answer is that a particle is an excitation of a field. I would probably add that the stable particles we normally think about are the non-dissipative states of an excitation.
“Why the quantum?”
The quantum world arises in phase space and is due to the linear dual relationship between position and momentum.
“Why relativity?”
Because the electromagnetic field imposes a linear relationship between space and time.
“Why the particular particles we have, why their masses, etc.?”
Still working on that one.
“Why the cosmological constant we have, and what is it anyway?”
The cosmological constant is a factor that tells us about the rate of dissipation of an out-of-equilibrium system
“Is the 2nd law of thermodynamics really a law?”
Yes, for all macroscopic systems.
“Etc.”
“How does string theory even begin to address questions that are actually fundamental?”
The identification of dualities is perhaps the most important contribution string theory has made to date. The fundamental importance of string theory is that provides a framework to deal with the problem of our inability to effectively deal with uncountable infinities.
“What is a particle?”
An M2 brane wrapped on a vanishing 2-cycle?
Shankar,
I would say that while US is very strong in astro and cosmo, US particle physics already tilted in that direction (SSC, string theory, model building, Witten deification…) but is now recovering.
I like a metaphor that occurred to me lately. Strings are the stones in “Stone Soup.” In the end, as Connes cited string theorists saying “… if some other theory works, we will call it string theory.”
It may be all the hype from the string people was useful in keeping funders interested in particle physics. It may also be that when all the congruances between string theory and observation involving other methods are worked out, nothing that absolutely required string theory will be present.
I am reminded of the controversy over the theory of fuzzy subsets of real sets (known mostly for its fuzzy logic component) when it started out – that it was simply a reformulation of already existing math. I hope that string/brane/M theories can at least give people a convenient way of showing another perspective on problems in mathematical physics. That doesn’t make the current “sociology” good but it may be a useful quality of string theory.
`Truth’ thanks for your responses.
I see that you have some reasonable answers,
and I see that you have some string theoretic answers.
However, the reasonable answers are not string theoretic,
and the string theoretic answers are not reasonable.
Here’s a link to something a propos:
http://abstrusegoose.com/137
Don’t get me wrong, I like string theory and I think that its important, but we have to look at it as a means to an end (just like any theory). My answers were not intended to be string theoretic, just reasonable.
“jamie”,
I’m not claiming that I have the answer to the puzzles that remain for fundamental theory, just that the speculative conjecture that string/M-theory in 10/11d can solve these puzzles has, after a quarter century of work by thousands of very smart people, been shown to be a failure. I personally think a deeper understanding of our current best fundamental theories is the most promising thing to work on now, so that’s what I do. Those who think that research direction is a “brain fart” should do something else.
It’s just an undeniable fact that the public in general, and physicists in particular, have come to recognize that there has been a huge failure here. 25 years of hype have blown up in string theorist’s faces, as it becomes clear that not only has there been zero progress on string unification, but the whole project has degenerated into pseudo-science (the landscape).
Your idea that the way to deal with this is more hype (“String theory is really nothing more than a structure that manages to relate all of the various ideas that have been useful in physics in the past hundred years”) and “calling me out” as “despicable.. underhanded… lying..” has already been tried during the past couple years. These tactics have been far more effective than anything I’ve ever done in convincing physicists and others that string theory really is in serious trouble.
Ray Saunders Says:
Re The End Of Science – anyone remember Charles H. Duell (Commissioner, US Patent Office) recommended it be shut down because everything had already been invented – in 1899.
This is simply incorrect. Duell did not make any such recommendation, in fact he and many other Patent Chiefs were concerned at times about the exponential growth of patent applications and how to handle them.
It’s one of those tales that people like to repeat to “prove” a fairly empty point. Try just sticking with Lord Kelvin next time.
jamie wrote above:
“There is nothing wrong with working on whatever you want (assuming of course, you have something non-trivial to say). The problem is when you present it as an alternative to fundamental theory, while NOT addressing the challenges of fundamental theory at all.”
No, the problem is when you claim that what you are working on is so interesting, important, crucial, or whatever, that it must absolutely be pursued at the expense any other topic in formal theory, and then aren’t able to justify that claim to meritousness in any tangible way. If what you folks are doing is so wonderful then go prove it by filling up the pages of Physical Review Letters with all your great advances. Considering how important your work is, it should be a piece of cake for you! 🙂