Today’s San Francisco Chronicle contains an article about string theory entitled “Theory of Everything” Tying Researchers Up In Knots. It’s by science writer Keay Davidson, and is about the most skeptical article on string theory I’ve seen in the mainstream press. The lead sentence is:
“The most celebrated theory in modern physics faces increasing attacks from skeptics who fear it has lured a generation of researchers down an intellectual dead end.”
Davidson contrasts Michio Kaku’s very pro-string theory point of view in his new book Parallel Worlds, with the much more skeptical views of Lawrence Krauss, who evidently has a book entitled “Hiding in the Mirror: The Mysterious Allure of Extra Dimensions” coming out in September. He also got comments about the current state of string theory from quite a few different people, including yours truly. The article contains a link to this weblog.
Some of the string theory critics quoted are just inherently opposed to any new mathematical approach to fundamental physics, something I have no sympathy with. One of these is Stanford’s Robert Laughlin, who makes the point that string theorists are trying to camouflage the theory’s increasingly obvious flaws by comparing the theory to “a 50-year-old woman wearing way too much lipstick.” Because of Laughlin’s extreme anti-mathematical theory views on the one side and those of his colleagues like Lenny Susskind on the other, “The physics department at Stanford effectively fissioned over this issue” says Laughlin. He goes on to say “I think string theory is textbook ‘post-modernism’ (and) fueled by irresponsible expenditures of money.” For the record, I’m no more of a fan of Laughlin’s views about particle theory than I am of Susskind’s.
Some of the quotes from defenders of string theory are a bit strange, with none of them addressing the fundamental problem the theory is facing these days as it becomes obvious that it can’t predict anything. John Schwarz is quoted as saying “string theory is the only approach that has the potential for explaining dark energy” which is kind of peculiar since it is well-known that superstring theory naturally leads one to expect a value for this energy density that is off by 120 orders of magnitude. The only way around this seems to be the “landscape” argument, in which you essentially give up any hope of ever predicting anything. The other defenders of string theory quoted in the article mainly try and claim that twenty years of work on the theory is still nowhere near enough, that it is way too early to be able to evaluate it yet. They don’t give any indication of how much longer we should wait for such an evaluation, but if twenty years isn’t long enough, it sounds like they hope this won’t occur while they’re still alive.
Update: For a very different take on this, see Lubos Motl’s posting.
It’s a very interesting article. Look at this quote from Philip Anderson: “we from outside the (string) field are disturbed by our colleagues’ insistence that every new semi-adolescent who has done something in string theory is the greatest genius since Einstein and therefore must occupy yet another tenure track…”. Has the Nobel Prize winning Dr Anderson ever participated in hirings of condensed matter theorists? They are usualy presented with even more hype because in addition to being genius they bring “million-dollar” grants. Do you believe that Dr Anderson criticism is honest? Welcome to the WWF physics of the XXIst century.
Jean-Paul
Quantoken said, Science is not a part of nature, but the part of human culture which tries to interpret what we know about nature, in ways we human can understand and reason with.
In a very real and non-trivial sense, science is a part of nature. It does not seem that arbitary changes to the known laws of nature (including apparently universal constants) are, in general, compatible with the existence of life. For many of the same reasons, it is not at all clear that science could get anywhere unless the physical universe had certain crucial properties.
Why might this be the case? If the evolution of life and science itself are fundamentally processes of trial and error, then one must ask: Under what circumstances can trial and error be effective? For example, suppose it was much harder than it is to construct and maintain isolated systems. How could one design and interpret experiments? What if effects like those assumed by astrologers were pervasive? One might have theories, but testing them would be much more difficult.
One of my objections to the more familiar formulations of the anthropic principle is that they short-circuit this question, although they implicitly or explicitly acknowledge its relevance. Aaron said, “On the other hand, I firmly believe that we have to practice science as if the anthropic principle were false.” I would say that we must either do that, or reformulate the anthropic principle in a way that is truly fruitful, and doesn’t subvert the whole enterprise.
I think this may well be possible. The key idea is to consider the logic of trial and error, and how it can lead to conclusions about the features and behavior of physical systems. In some sense I think the logic of trial and error, combined with certain very simple dynamical notions, may ultimately largely dictate these features and behavior, and the laws of physics themselves. I have been influenced in this direction by the writings of Karl Popper and Edwin Jaynes* and some younger (and still living) Bayesians, such as Carlton Caves. I’m not sure what they would make of the ideas I’m advancing here. (Incidentally, the relations between Popper’s philosophy and that of the Bayesians is a topic for a long article or a book.)
Peter said:
“I’m just completely amazed by the fact that intelligent, trained scientists are unwilling to admit an absolutely undeniable fact staring them in the face. If it really is true that string theory can’t predict anything, it’s not physics, and anyone claiming to be a physicist has to admit that, as physics, it’s a worthless idea and has to be abandoned.”
Peter, don’t you see as I already pointed out. Doing so for string theoretist amounts to career suicide. No amount of scientific training is enough to prepare one to commit suicide. An intelligent scientist would want to continue to survive in the establishment camp. Science honesty is only secondary thought after survival is taken care of first.
For people old enough to have established tenureship and un-shakable credibility in the science community, but still young enough to have enough lifetime left to explore completely new exotic ideas. They may listen to you, Peter. Anything above or below that age threshold, I do not think they will ever listen.
Quantoken
Aaron,
Yes, nature is what it is, not what we want it to be, and this is a lesson string theorists are having a hard time facing up to.
If the string theory framework is not predictive, you’re right that doesn’t logically imply that it is wrong. But it does imply that it is something worse than wrong. It is not science, is completely useless, and is nothing more than a fairy tale. People who don’t believe in the scientific method are free to promote it as having something to do with reality, but they have no business doing so from within university physics departments.
A few years ago, if you had told me that once it became clear string theory was a non-predictive framework, string theorists would refuse to abandon it and instead would start going on about how “we may have to rethink what it means for a theory to explain experimental data”, and basically give up on the whole idea of science, I would have refused to believe you.
I’m just completely amazed by the fact that intelligent, trained scientists are unwilling to admit an absolutely undeniable fact staring them in the face. If it really is true that string theory can’t predict anything, it’s not physics, and anyone claiming to be a physicist has to admit that, as physics, it’s a worthless idea and has to be abandoned.
Aaron said:
“I think it’s sometimes worth pointing out that just because the landscape isn’t predictive, that doesn’t make it wrong. It’s not imaginable that that’s how the world really is. It’d be disappointing, but nature is what it is, not what you want it to be.”
You forget the title of this BLOG is “Not Even Wrong.”, which is worse than being wrong 🙂
Nature is what nature is. Science is not a part of nature, but the part of human culture which tries to interpret what we know about nature, in ways we human can understand and reason with. Therefore, the whole idea of science is based on the philosophical belief that the nature is rationable, knowable and predictable. If you give up on the notion of nature’s predictability, you give up your right of being called part of science.
Michael Nauenberg: What you said is wishful thinking. For string theorists to do what you said would be professional suicidal, to admit that the whole idea is a dead end and they have wasted tax payer dollars for decades on a futile pursuit, which is also a waste of their own intelligent lifetime. It simply would not happen.
Change is only possible, IMO, when the old generation die out and the idea of super string gradually fade out. Unless there is a up-down revolve of changes starting with re-appropriation of research fundings.
Quantoken
I think it’s sometimes worth pointing out that just because the landscape isn’t predictive, that doesn’t make it wrong. It’s not imaginable that that’s how the world really is.
Aaron, how would you establish that the landscape is correct?
I think it’s sometimes worth pointing out that just because the landscape isn’t predictive, that doesn’t make it wrong. It’s not imaginable that that’s how the world really is. It’d be disappointing, but nature is what it is, not what you want it to be.
On the other hand, I firmly believe that we have to practice science as if the anthropic principle were false, but that’s another story.
It seems to me that at this point it would be
best if string theorist would stop going public
with unscientific hyperbole. Whatever
merits the theory may have, announcing that the string “landscape’ of 10^500 (or is it 10^501) multi-universes explains
the observed constants of nature
in “our” universe (anthropic principle) is nonsense characteristic of theologians of the middle ages.
> So don’t fool yourself that a
> tenure track position taken away from a string
> group will be used to hire a mathematical
> physicist working on (fascinating) Clifford
> modules — such a position will go to a nano-
> theorist..
.. which in fact is very good, isn’t it? One can be a mediocre nanoscientist and still be useful. Obviously this is not so in string theory.
> Parallel universes, time travel,
> miniature black holes
Your examples are all pretty old stuff and were “invented” before the superstring mania.
This shows that superstring theory did not even contribute to science fiction, like all other great theories before.
These days it seems that obsessive hype-mongering is a prerequisite for any field to maintain a degree of public attention. With nanobots, age-reversing immortality drugs, hyperintelligent AI all just around the corner, according to the press releases, how is the physicist to compete? Parallel universes, time travel, miniature black holes- at least it gets your picture in the paper.
The present problem of high energy phsyics started 30 years ago when the great success of theorists attracted many brillant students to theory, but at the same time closed main problems and ultimately slowered experimental progress. In this situation string theory was a good attempt of doing something. Passing to some other mathematics would not solve the problem.
Hopefully LHC will make real progress and indicate where good physics is. And a few more hyped theorethical books will indicate where it is not.
Peter – Being at the math department of Columbia, you maybe not be aware of the situation outside Princeton, Harvard etc. Everywhere else any non-applied theory is under constant attack of the prophets of new physics who work on applications of such advanced theory as Hooke’s Law to molecular motors etc and bring tons of money from NIH, DOD etc.
The criticism of some Very Famous theorists comes from jalousy how such an underfunded field like string theory could create so much hype and publicity. Unfortunately their response is to follow the bad example and to create their own hype — promise that physicists can find a cure for heart attacks, explain the origin of life etc.
So don’t fool yourself that a
tenure track position taken away from a string group will be used to hire a mathematical physicist working on (fascinating) Clifford modules — such a position will go to a nano-theorist. Make your own call…
I’m actually not of the opinion that the amount of money spent on string theory is a problem. It’s negligible compared to all sorts of other things, many of which are no more worthwhile.
The motive behind the string theory hype is not only to protect NSF and DOE grants, it is also to ensure the dominance of string theory in those physics departments where it has become entrenched (Princeton, Harvard, etc., etc….). The important question to me is about how to make it possible for good young people to try to do something new. In his comments in the article Phil Anderson also focuses on this saying he is
“disturbed by our colleagues’ insistence that every new semi-adolescent who has done something in string theory is the greatest genius since Einstein and therefore must occupy yet another tenure track.”
What can be done to change things so that young people don’t feel their only hope of a permanent job in mathematically-based particle theory is to do string theory? I happen to think that puncturing the string theory hype is a necessary first step, but far from sufficient.
String theory at Average Respectable University is a negligible fraction of the total funding as compared to bio, nano and neuro. While it is fair to criticize its scientific merits and outrageous self-promotion of some individuals, your over-funding criticisms should be directed towards other fields: these days hype and lies are everywhere (which of course doesn’t justify saying that strings solve the dark matter problem or that you can see them in the sky or that LHC will be a black-home factory…)
Dear Fyodor Uckoff,
Even if super string theory becomes the ONLY theory funded by public money, so you have no competitor funding wise, and even Lee Smolin et al., John Baez et al. all publicly acknowledge that their approches are wrong. Does that make super string theory a winner?
No, absolutely not. You are still a complete loser since you still can not predict anything. And you would be a very sore loser since you can’t even acknowledge your failure, while Lee Smolin is at least ready and willing to acknowledge failure if they can not succeed.
Theory developments are not ball games in which there is always one and only one winner. Theories are not used for competition of funding, but for explaining the nature. So there doesn’t need to be a competition. If none of the existing theories can make a verifiable prediction, then all of them are losers. If two theories can both explain the same thing, then both are winners and there may be a third winner unifying them behind.
So a good theory really doesn’t need to compete against any one else. If it is correct it will be correct on its own merit. If it is wrong it is wrong on its own fault.
The fact that string theorists are SO jealous against other theories, really tells you that they simply can not establish their own validity on their own merit, but will have to base it on “competition” against other theories, and declare their victory based on their dominance on fundings. What a sore loser!
Quantoken
Fyodor said “And even if it were true that string theory has been “hyped”, what harm would that have done?”
You can’t be serious, can you? If a field of physics is hyped and turns out to be totally and completely wrong (or worse, totally unpredictive), then this has done serious damage to the progress of science. It slows down science by (1) maintaining a monopoly on what is considered acceptable for theorists to work on (and not just theorists in high energy physics), (2) stripping money away from other fields of physics and science which are more deserving of funding, and (3) reducing funding for all of science by reducing the public’s trust in science. If the “great” leaders of string theory turn out to be following nothing more than a dead end, then it does serious damage to all of science.
Further, while there may be no alternatives to string theory at present, this does not mean that we should continue to fund it. It may be that the idea(s) necessary to reconcile quantum theory with gravity simply have not been put forward, and spending my money on a dead end (if that’s what it is) doesn’t seem to me like a very productive thing to do.
If you have a string theory argument for the value of the CC other than the anthropic landscape one, tell us what it is instead of just writing “Who says” in response to my post. I’m the one saying it. If you think I’m wrong, tell us why so we can learn something.
I have never said “there are lots of theories out there which would have explained everything by now if only they had not been starved of funding by the string theorists”. There aren’t any good ideas out there about how to go beyond the standard model, but having most of the community working on an idea that has failed and refusing to face up to the fact that it has failed doesn’t help the situation. The reward structure of the field is still that if you are a smart young theorist and decide to work on a speculative idea that is not string theory, you probably are ruining your hopes for a career, whereas if you work on a speculative string theory idea (even if it is clear that it doesn’t work), you can do quite well for yourself.
I don’t expect Witten to announce tomorrow “String theory has failed as a TOE, people should go out and try and find other new ideas”. But he really should do this, and it would have a very positive effect on the field if he did.
Peter Said: The only way around this seems to be the “landscape” argument,
Who says?
And even if it were true that string theory has been “hyped”, what harm would that have done? It’s not like the theory has any competition. The notion that there are lots of theories out there which would have explained everything by now if only they had not been starved of funding by the string theorists is pure conspiracy theory at its most ridiculous. The people being starved of funds and attention are the kooks who tend to post in blogs like this one until Peter kicks them out. Where’s the real competition? Does anyone really expect Ed Witten to announce: “String theory has failed. Go work on something else. What else? Go look at Tony Smith’s or Quantoken’s web pages…..”
Peter said:
“…since it is well-known that superstring theory naturally leads one to expect a value for this energy density that is off by 120 orders of magnitude.”
Sorry I must set the record straight here, although I am definitely not a defendent of super string theory. That 120 orders of magnitude is NOT the fault of string theory alone, but the fault of whole existing physics theories which could not unify QM with GR. You have the 120 orders of magnitude ever since vacuum energy was proposed and calculated, which is much earlier than the occurance of super string theory. You can not blamn super string theory for a problem that occurs before it, although super string theory does not lead to any thing better.
Put it simple, regardless of what theory you are in, any time you put the three constant hbar, C, G together, you naturally get the Planck Scale. Any time you deal with Planck Scale, the characteristic energy density, which is approximately one Planck mass per Planck volume, is automatically 120 orders of magnitude too larger, compare with the cosmological constant.
So any theory, not just super string theory, that talks about Planck Scale at all, inevitably runs into 120 orders of magnitude. That is, unless the math of the theory itself leads to a dimensionless number which happen to be very small but none zero, approx. 10^-120, which exactly cancel out the other 10^120 figure from Planck Scale. That is what the “landscape” business is all about. But that’s a complete failure as we know.
There are theories which discard the Planck scale and so get rid of the 10^120 as well as difficulty in explaining the cosmological constant. But obvioulsy Peter is not interested in hearing alternative theories and I am not going to elaborate here.
Quantoken