The anthropic string theory landscape seems to be having ever greater success in taking over fundamental physics and turning it into pseudo-science. It’s being promoted by no less than 2008 presidential candidate Wesley Clark, the following is from a transcript of his remarks to science bloggers at a blogger convention in Las Vegas:
Read Leonard Suskind’s new book, called “The Cosmic-” It’s called “The Cosmic Landscape And Intelligent Design” if you want to see something that’s overpowering. Suskind is the inventor of cosmic string theory, and what he does is he takes cosmic- he takes the idea of the universe. He says the universe is- see, what’s happening in intelligent design is people are saying, ‘Ah well, you see, the, the, the wavelength of, of, of the electron and Planck’s Constant and all these numbers are so odd. They don’t- they’re not even numbers, you know. They, they, they don’t balance each other. It’s sort of 1.- It’s like the figure of pi, 3.14159… Why would it be such an odd number? Why, why wouldn’t god make the universe, you know, symmetrical?’
(laughter)
Then they said, ‘well, because, you know, it’s like there’s only one on 10 to the 50th chance that the universe could have worked out in a way that mankind could survive. Therefore, you know, this must have been an intelligent designer who created this universe especially for us.’ What Suskind does is he turns it on its head. He says, “You know, if you look at string theory and the 9+1 dimensions” or 10+1 dimensions, and I’m not sure how he knows that time only has one dimension, but he does. (inaudible) would say I’m very arrogant for questions questioning this.
(laughter)
But what Suskind does is he turns it upside down. He says, “Look there are- there is an infinite number of universes.” He calls it a multiverse, and he says that however the motive forces, and nobody understands why quarks pop in and out of existence. Nobody understands it, but apparently they do. And apparently there are many, many universes, and we’re here in this one. And maybe there are others in which Planck’s Constant has a different number, in which the speed of light is not 186,200 miles per second. Who knows? We don’t know.
Commenter Patrick wrote into point out a review article on this from graduate student Joseph Conlon, published in the latest issue of Contemporary Physics (not available on the arXiv or anywhere else for free as far as I can tell). It’s entitled, “The string theory landscape: a tale of two hydras”, with the first hydra the non-renormalizability of gravity (supposedly slain by string theory), the second the prolifieration of vacuum states. Conlon seems to think that the fact that string theory can’t ever be used to predict anything is not a serious problem:
We started with a dream of a unique string theory compactification reproducing the structure of the Standard Model. This is a dream apparently shattered by the existence of the landscape. Granting the landscape and its existence, does this mean string theory is inherently unpredictive at low energies? If this is true, this is sad but no disaster. Quantum field theory, of itself, is also unpredictive.
I’ve written elsewhere about why this analogy with QFT doesn’t hold, but on the face of it there’s obviously something wrong, since we use QFT all the time to make detailed, testable predictions about the real world, something that string theory, according to Conlon, will never be able to do.
Talks from the plenary section on “naturalness” at SUSY 06 are online. The usual advertising job from Susskind and Linde, the one that seems to have impressed Wesley Clark. Wilczek gives a more substantive talk, and seems to have some interesting new speculative ideas about models near the end.
On another topic, I’ve been wondering what the current state of peer-review of hep-th papers is. Personally I think it has been several years since I’ve looked at any of the main journals that publish papers in this area, and I suspect this is true of many people these days. The Bogdanov affair several years ago showed that refereeing in this area had become pretty much a joke, with the brothers having no trouble finding five journals willing to accept utter nonsense.
Looking at the arXiv and SPIRES listings, which seem to contain publication information after submitted papers have been accepted, many papers (e.g. Susskind’s single-authored papers on the landscape), don’t seem to ever have been peer-reviewed and published. I’m curious what people think of this. How many hep-th authors have stopped submitting their papers for refereeing? Is the data on the arXiv and SPIRES an accurate reflection of this? Does the fact that an author’s preprints don’t have publication data for the last few years mean they weren’t submitted for refereeing, or could this be due to time lag in refereeing/publication, or incompleteness of the data?
Update: Courtesy of Google, there’s now an on-line talk by Washington Taylor promoting the Landscape to people working for the company. He gives the number of vacua as at least 101000. The number of well-known physicists out there promoting this nonsense to the general public is amazing (via Lubos).
I haven’t submitted my single-authored papers (or books) to publishers in 10 years. But most of my papers are with others, and I haven’t forced them to do the same. I don’t have much faith in the refereeing system. Besides, by the time they publish something, it’s history. And then there’s the problem of errata.
Susskind has no peers, therefore it is impossible for him to be peer reviewed.
There is actually quite a few famous papers which have never been published, for example
hep-th/9805114,
hep-th/9907189,
hep-th/0006071
and
hep-th/9701025
😉
Kasper
a) Bloggers have conferences?
b) Why would Wesley Clark even read the book? Did Susskind give him a copy?
c) The whole attitude to the landscape is wrong. First, you need an acronym. “Anthropic string theory landscape” is a non-starter. Landscape (of) anthropic string theory = LAST ~ Lubos Adores String Theory. Now we’re getting somewhere. Next print some t-shirts and make some money off of ST, instead of railing against it.
In the astrophysics community, it is somewhat rare to see a paper in the astro-ph that has not been at least submitted to a refereed journal. Of course the refereeing system is faulty sometimes and needs some reformulation. (For instance, it would be interesting that the authors’ names be omitted for review in order to reduce some prejudice on the part of some referees and to allow them to unbiasedly focus on the paper contents. There are other problems as well, I could talk about a few examples, but I do not think Peter Woit intended to open a whole thread on this.)
I do find it strange that the majority of papers in the hep-th (is it correct, the majority?), including those considered important contributions, are not submitted for refereeing. Being myself used to post on the arXiv only after having my papers accepted to a good refereed journal, maybe this is just my personal impressions. In any case, I have learned this good practice from my supervisor since I was an undergraduate student, and I am quite satisfied with it.
The arXiv is a great idea, but I do not think it is a substitute for the refereeing system (despite its flaws), specially if your work is supposed to represent a significant contribution to the field. It must somehow be appropriately reviewed.
I think that peer review works pretty well, at least for the better journals. In high-energy theory, this means Physical Review Letters, Physical Review D, Physics Letters B, Nuclear Physics B, and some others. It is very difficult to get something that is pure rubbish published in those journals. By “rubbish,” I mean a paper that is flawed in a fundamental way–a paper will problems in its conceptual or mathematical underpinnings. (How interesting physically some of the results published in these journals are is a separate question.) The fact that almost all the high-energy theory papers submitted to these journals appear in advance on the arXiv is good for the peer review process, since referees can (surreptitiously–or perhaps not) get input from their colleagues about papers they are reviewing.
Most people I have interacted with in the high-energy physics community certainly do pay attention to whether and how papers are published. Publication in the journals I listed above means something; however, publication in many lesser journals does not. It is understood that peer review is significantly imperfect, and even extremely poor papers can be slipped into minor journals if the authors are diligent. I think many serious physicsts would never even submit a paper to one of these publications; if they can’t get papers published in top-tier journals, they just leave those papers on the arXiv and don’t bother trying to get them published somewhere else. Of course, there are journals that occupy a sort of middle ground and are somewhat respected. The Journal of Mathematical Physics is still considered to have fairly high standards for correctness, but the papers published there are usually expected to be less interesting than those published in more prominent journals.
Peer review for the better journals can be uneven in quality. Good papers get held up by difficult referees, while somewhat weaker (still correct, just less interesting) papers may slip by with little comment. However, while there is some noise, there is also a clear correlation between the quality of a paper and how likely it is to be rejected. When I have gotten negative referee reports, I have always (with one exception) understood the referee’s point. Obviously, I disagree with the referees, but these rejections are not being made for stupid reasons; the reviewers have put time and effort into evaluating my papers. I have also appreciated the many comments and suggestions for minor improvement that I have received in more positive reports–again, clear indications that the referees are almost always paying attention.
Speaking as a referee, however, I know it can be difficult to reject a paper that has some interesting ideas, but which also contains some serious mistakes. I have never allowed a paper like that to be published, but one cannot help but feel empathy for authors who may have put months of work into something (and come up with several innovating ideas), only to be undone by a small but crucial mistake they made early on.
I agree authors names shouldn’t be passed on to reviewers, but neither should the laboratory name unless it is an experimentally based paper. Peer review is only meaningful is the reviewer has to review the content. Usually it is the exact opposite, with journals requesting names of peers to sent the paper to review to. This is asking for bias. It makes it easy for mainstream and virtually impossible for outsiders. arxiv could easily be reviewed by blog trackbacks, if someone would be objective about it…
The social dynamics of the string community is that of a sectarian totalitarian system, hiding from the rules of scientific objectivity, due to the absence of both experimental provability and disprovability.
The string theory community is a personality cult with Witten its high priest. Once Witten retires, chances are high everything will pop like a soap bubble (or like the high tech stock market crash not long ago), leaving the reputation and credibility of theoretical physics in pieces for decades to come.
Witten creates credibility among the mathematicians, by his ingenious works in geometry and topology that have nothing to do with string “physics”. On the other hand, he has surrounded himself with an army of loyal, brainwashed followers who dress like him, who talk like him, who write preprints in same style format like him. The string community is like a mass of half-baked Witten clones, with some members more prone to hysteria than others. One has to study mass cults in order to understand the personality defects that motivate people to join such movements (presumably, weak self-respect, paired with a will to power, plays a role).
One should read the episode “The Grand Inquisitor” in Dostoevsky’s “Brothers Karamasov”: The devil tempts Jesus in the desert, and explains to him that humankind will follow anyone who provides them with bread and miracles; therefore, an overwhelming demonstration of the power to support people with food, and with miracles, would convince humankind to forfeit its free will, and to follow that person wherever he/she pleases to go. But Jesus refutes this methodology; he wants people to follow him out of free will and belief. Witten makes a different choice than Jesus in Dostoevsky’s piece. He provides his followers with jobs and miracles, and they literally follow him to the end of the world of theoretical physics.
Fortunately for humankind (or at least for future generations of theoretical physicists), there is no successor to Witten. Therefore, there is reason for the joyful hope that the string hysteria will evaporate in a couple of decades.
On the other hand, one has to admit that string theory has produced amazingly interesting mathematical insights. If things go well, some mature parts of string theory will be absorbed into a branch of topology or number theory, which is ok and worthwhile. I just hope that string theory will disappear from the physics landscape, not because I particularly resent it, but because I’m scared by the populist, totalitarian, sectarian social dynamics of the strings community.
And if some string theorists insist on the eternal lifespan of their favorite theory, I would like to remind them of the fate of communism, and of that of other totalitarian systems, which were defended as vigorously by their proponents some decades ago.
Brett,
I agree that the review process is useful when you can talk to the referee, argue, and get feedback. Now, how would you argue with the Editor of one of the fine journals you mentioned when in response to my submission he writes this?
In general, [journal] does not publish purely formal developments of old and well-established theories or alternatives to old and well-established theories if the new alternatives do not make different predictions that can be experimentally verified; if the new alternatives do make different predictions, it must be shown that the predictions are consistent with the present experimental situation. Applied to your manuscript, this policy would require that you provide an explicit, detailed, and quantitative prediction of your theory that differs from the predictions of standard quantum electrodynamics. Since you have not done so, I am afraid that we cannot accept your manuscript for publication in [journal].
After I explained the relevance of my work to current and future experiments, I got
I am afraid that, even after considering the points that you make, I still conclude that your manuscript is not suitable for publication in [journal].
End of story. How can I argue with that?
Eventually, this paper was published as
E. V. Stefanovich, “Quantum field
theory without infinities”, Ann. Phys. (NY)
292 (2001), 139
(there is also a copy on the web if you are interested) So, you can judge for yourself whether it has anything new to say about QED and its agreement with experiment.
Eugene and others,
I’d rather not start a discussion here of refereeing itself, it’s a huge and complicated subject. What I’m trying to understand is how widespread is the phenomenon of people giving up on the journals and refereeing system, just ignoring them. I see more and more of what looks like evidence of this happening, and Warren provides another data point. Given the fact that virtually no one looks at most journals anymore, this may be an increasing trend.
One comment: I don’t think absense of any journal reference on the arXiv means anything about publication … it means the author was too lazy to update the arXiv. You can often find journal versions of quant-ph articles by googling, even when there is no pointer on the arXiv. It would be interesting looking at a sample of hep-th articles from several years ago, and see how many are still unpublished.
Peter,
I was looking more at SPIRES, which I believe they update automatically with journal information as the journals come out. This isn’t up to the author. But if anyone knows differently, I’d be curious to hear about it.
One set of examples of papers that don’t appear to have been submitted to journals are Susskind’s, e.g.
hep-th/0302219 (the original anthropic landscape one with 257 citations)
hep-th/0407266
gr-qc/0503097
gr-qc/0504039
hep-th/0101029
hep-th/0011164
Another example would be Jacques Distler, who doesn’t seem to have any published papers since one he wrote back in 2001.
If anyone knows of how to find out if and where these papers were published, let me know.
The Great Inquisitor
A perfect analysis of the sociology underlying string theory! It is very unfortunate that in order to write something like this one has to use a pseudonym (at least before retirement), whereas the Lord of misuse (comissioned by the hegemonic string court to prolong the lifetime of string theory beyond the lifetime of their protagonists) can spread his vitriolic brew to confuse young physicists and frighten more knowlegeable and mature members of the community.
Ha! I was wondering Peter when you would run across that. I have some vague vision of long Woitian tentacles spreading across the web in search of anything landscape, and I’m sure they don’t miss much.
Let me elaborate a bit on what I meant. Almost by definition, it is very hard to find exclusively stringy predictions at low-energy that cannot be reproduced by effective field theory. If you are willing to go to Planckian energies, then we can run with exponentially soft scattering amplitudes and towers of excited stringy states, but there are no Planck-scale accelerators and this is somewhat of a toy game.
However, all effective field theories are not equal. There is clearly lots of structure in the Standard Model that is bursting for an explanation. One example: the QCD theta angle. Your underlying theory has a big role to play in the models you use to try and explain and understand the Standard Model. There are better and worse ideas on what are the underlying principles – e.g. base 10 numerology is mostly held to be an unpromising idea. In this sense I regard string theory as the best organising principle for thinking about models or effective field theories explaining the structure of the SM.
So, at low energies, I see `string theory’ as conceptually analogous to `gauge symmetry’, `spontaneous symmetry breaking’, `quantum field theory’, etc. It is an organising set of ideas and assumptions that is not *in itself* predictive but sets the framework to build predictive models. Clearly `models inspired by string theory’ do not compare experimentally with `models inspired by gauge symmetry’, but that’s why the one is research and the other taught in undergraduate courses. String theory does differ in that it has wonderful UV properties and is intrinsically predictive in that regime, but I’m not holding my breath for the Trans-Galatic Super-Duper Quasar Collider.
If you can argue technically that you can get any effective field theory out of string theory this may not apply – but this is certainly false for the IIB flux vacua that provoke all the chatter about 10^500 and so on, as these have rather similar properties.
I also note that on a personal level I am far more interested in the correctness of My Models than in whether My Models are a unique low-energy prediction of string theory.
I see some of these landscape discussions as more sociological than anything. Maybe in 1985 people thought string theory was about to explain everything in two weeks. I don’t know, I wasn’t around then. I don’t think people enter the field now with that illusion. The theory is still vastly more capable of talking to the particle physics-GR-cosmology triangle than anything else. It’s not a binary distinction between a theory that predicts everything and a theory that is entirely useless.
Best wishes
Joe
I realize that this is off topic, but I was asked a direct question, and I want to respond.
Eugene-
I too have had a paper initially rejected because it did not state any specfic predictions that the referees deemed sufficiently important. My response was to add futher numerical calculations detailing the non-standard model behavior. You comments seem to imply that you did not make any changes to the manuscript after receiving the rejection, but merely tried to convince the referee of your paper’s importance. However, I think the referee initially had a quite valid point, as I did not see any new predictions in your paper, and so I am not surprised that he did not change his mind.
Peter,
I think there are rational explanations of why people may prefer arXiv publication to refereed journals. I suspect that Susskind does not care anymore about his publication record, so why bother to submit papers to journals? Others may have less impact papers that simply add finer details to the points made in their previous journal articles. So, they decide not to go for the full-blown paper. I have a couple of those in the arXiv. Yet others (mostly those who are out of the mainstream) may give up after referee’s or editor’s rejection.
Brett,
if I may, just a few points. First, the person who wrote this was not a referee, but the journal editor. You can have a discussion with the referee, but if the editor rejects your manuscript, you are done.
Second, if you read the paper more carefully you’ll see that it opens up a whole new class of experimental predictions which go beyond the S-matrix and allow one to calculate the time evolution of interacting systems. It is another matter that such a time evolution is beyond the resolution of modern experiments. However, one doesn’t need a “Trans-galactic Supercollider” to see it.
Third, I am wondering how many string theory papers satisfy the stringent criterion of providing an explicit, detailed, and quantitative prediction ?
Aw, come on.
Clark planned to become a physicist back in high school, but now he’s just a really smart guy who picked up a book to read for pleasure on topic he enjoys. Don’t expect him to be up on what’s going on.
The current guy in the White House can barely read. Here’s a guy you could talk to and is open to learning more.
Appreciate it.
catherineD,
Wasn’t really complaining about Clark, just marveling at how far into the culture this whole landscape thing has gotten.
Joe,
Thanks a lot for writing, it’s too late tonight, but I look forward to reading carefully what you have to say tomorrow.
I went through some talks of the SUSY conference.
The funniest one is Linde’s slide that says about the anthropic principle:
“IT IS SCIENCE”
Every child knows that science is about making predictions and be tested by experiments….but these old physicists, that have no more ideas, want to convince us that science fiction is science.
Probably every other scientist outside theoretical physics (people who that are used to experimental verification!) would think these people are just crazy.
…and it is sad to see how throetical physics (that was once upon a time the mother of sciences) is leaving the objective scientific method to go into the world of the opinion, where some famous powerful person decides what is good and what is bad….and not experiments.
I just watched W Taylor’s lecture on google. It’s scary how intelligent people can give talks like that.
dear Joe,
recently people liked to speculate about brane-worlds with large extra dimensions because this allows quantum gravity at the TeV scale: LHC would be your Trans-Galatic Super-Duper Quasar Collider. This scenario was motivated by string theory, and gave to string theorists an opportunity to show what they can really do. The resulting literature shows that all concrete work was done by phenomenologists who tried to apply Einstein general relativity by avoiding or parameterizing (and sometimes ignoring) UV divergences.
Even in the quantum gravity regime, string theory failed to give results. Some examples:
Q: What is the mass of the string states in units of the quantum gravity scale?
A: it depends on the dilaton vev.
Q: What is the tension of our brane?
A: It depends on how supersymmetries are broken.
Refereed journals are still relevant in fields that produce results relevant for different fields.
For example, hep-ph and astro-ph contain some papers that experimentalists consider relevant. But experimentalists often are not expert enough for judging themselves if such papers are correct, and therefore often adopt the following rule: only papers published on good refereed journals are ok.
Peter,
thank you for the link to Washington Taylor’s video. Believe it or not, I’ve never heard this full story from the mouth of real string practitioner. My opinion about the whole enterprise is this: childish logic + superiority complex + arrogance + fanatism. We have entered dark era, indeed.
Dear anonymous,
Of course I’d be very happy if TeV-scale Large Extra Dimensions were seen at the LHC. But there are lots of hints that the cutoff scale should be larger (axions, cosmic rays, proton decay, neutrino masses, GUTs…) and I for one would be surprised if they were found. Long odds, big payoff. I also don’t think `string theorist’ is an identikit. Some who work on string theory are algebraic geometers at heart, others only care about BSM phenomenology, and most are some way inbetween. It’s a big community. If `string theorist’ is only used to refer to the former, then of course such people never go near BSM exotica.
I’m not quite sure I understand your Q and As. Stringy states have masses given by the inverse string length, which is determined by the volume and dilaton. We don’t know the string scale, but it’s always less than the Planck scale. With the second, there are universal formulae for brane tensions which are in e.g. Polchinski. I also don’t see how brane tension is an (easily) measurable quantity.
Best wishes
Joe
Wasn’t really complaining about Clark…
I’m am… complaining about anybody that is that quick to stereotypically follow suit with the all-to-familiar mindset of a pack of anti-fanatics who choose to willfully ignore the strongest implications of empirical evidence by instead automatically reaching for the most extreme anticentrist cop-out on first principles in the history of science in order to counter-respond to fundamentalist abuses of the evidence.
Panel of extremists:
science panel w/gen. wesley clark, chris mooney, pz meyers and darksyde
Michael Moore has a better shot at 10^500:1
~
And thank you, Peter, for being clear:
The anthropic string theory landscape…
I haven’t read Susskind’s book, but the inclusion of “intelligent design” in its title demonstrates the cheap moral standards and ethical bancruptcy in his community. Although the content of the book may prove otherwise, his choice of a title shows that he intends to get customers from another sectarian group of extremists, namely the right-wing Christian right.
The present US government is the first in recent times not only to have understood the size and the power of the Christian right, but to also cast aside ethical concerns, and to use it to its advantage. This is clever, but of course also degrading and ethically reproachable. Maybe the strings people only see it as clever propaganda, and are planning to learn from it.
What distinguishes a typical member of the strings community from a traditional physicist or mathematician is surely not intelligence; there are some extremely smart ones among them. It is their failure to feel an obligation as a scientist to a scientifically verifiable truth. The problem is a lack of scientific ethics. They trust the visionary abilities of people like Witten more than scientific objectivity and scientific method. This is an extremely dangerous, and short-sighted road. Witten does possess self-restraint and good taste in mathematics, but most of his followers don’t. They inadequately use mathematical language, which they only understand marginally, to try to impress all sorts of people, including Wesley Clark. The question is who they believe to do a service for, string theory, theoretical physics, or science ?
I am not concerned that after the Witten era, the strings movement will navigate itself into oblivion, due to the bad taste and lack of self-restraint of its members. However, their present propaganda is scientifically unethical, irresponsible, and dangerous.
Although the content of the book may prove otherwise, his choice of a title shows that he intends to get customers from another sectarian group of extremists, namely the right-wing Christian right.
Capitalizing on the popularity of the politics while blackmailing the string community.
Island,
What Susskind says here is that the only alternative to ID is strings and landscape. This is complete BS. The truth is that ID is based on an argument that is inacceptable to scientific methodology; it is not scientifically verifiable.
ID argues as follows: We have this creationist theory that explains the universe for those people who believe in it. Since it is not accessible to scientific disproof, it must be true.
String theory argues in a very similar way.
So it’s in a sense true; string theory and ID are both belief systems, one mathematical, the other not, which are neither provable nor disprovable by scientific experiment. So their claim for truth is similarly vacuous.
But it should be emphasized that Susskind is extremely irresponsible in not putting it this way, but to claim that strings + landscape is defending physics against ID. This is not true. Strings is not traditional physics based on scientific methodology.
dear Joe,
I fully agree with you that lots of hints disfavour TeV-scale quantum gravity is unplausible. Indeed, what keeps this possibility alive is the fact that we do not have a predictive theory of quantum gravity, so that we can make optimistic speculations.
Concerning my Q&A, the main issues that phenomenologists would like to know are: supposing that “quantum gravity” is what cut-offs quantum corrections to the Higgs mass, how much is the D-dimensional Planck scale? And the first string excitation? And the tension of our brane? 1 TeV? 5 TeV? 200 GeV? String theory does not give any useful answer.
Collisions of particles excite brane fluctuations giving missing energy signals that are detectably large if SM particles live on a brane with tension smaller than about a TeV. Formulae for brane tensions on Polchinski book apply when many supersymmetries are unbroken, not in our universe.
The actual name of the book is “The Cosmic Landscape: String Theory and the Illusion of Intelligent Design”.
and Wesley Clark is just trying hard to make himself look cool to geeky voters.
Joe,
The problem with your philosophy of string theory = generator of models is that it generates far too many of them, and the ones that look at all like the real world are ridiculously ugly and impossible to do precise calculations with. The theoretical framework of these models gives an infinite number of publishable research projects for people to work on, but zero reason to believe that this will ever lead anywhere, and no way of ever showing it is wrong. There is no criterion in this game for when to stop, give up and admit it doesn’t work. Your only hope is for a miracle to happen and something orders of magnitude more successful (in agreeing with the SM, being computationally tractable, and constrained enough to allow predictions) to all of a sudden appear. Hoping for a miracle is not a valid scientific research program.
Hi Peter,
The judgement of whether research programs are promising or not is subjective. Both reasonable and unreasonable people disagree. On the issue of whether string-based models are promising things to work on, I happen to think you are dead wrong. Of course, it’s your prerogative to disagree 🙂
Best wishes
Joe
>Hoping for a miracle is not a valid scientific research program.
What scientific research program would you propose?
“What scientific research program would you propose? ”
– Presumably any where the following is false:
“There is no criterion in this game for when to stop, give up and admit it doesn’t work. “
> Presumably any where the following is false:
Which is?
This is a serious question. If Peter or you suggest to give up on string theory, then it is a legitimate question to ask what better alternative you have.
What theory are you or Peter working on which will help us determine the value of the cosmological constant?
Wolfgang, you are posing a false question. One need not be working on some lesser nonsense in order to call the bluff of greater nonsense. We may simply have to say that there are no viable ideas today for the theoretical determination of the cosmological constant. It is better to face that truth than to have false hopes about some program. Activity for the sake of activity (what will we do otherwise) is pointless.
Joe,
Reasonable people can disagree about prospects for these models, but I’ve been watching people work on them for almost 22 years, and they are further away now from being able to use them to predict anything than at any previous time. The derivative has the wrong sign.
Wolfgang,
Unlike many of my dear commenters I don’t want to use this forum to endlessly promote my own favorite ideas. I did write a long paper about some of these, and hope to get some other things written down in the future. If you look at the non-string theory things I write about on this blog you can get an idea of what I find interesting. Obviously I don’t know how to compute the CC, if I had to guess I’d guess that the answer to that problem will come after you solve some other problems. Just thinking about the CC is probably not going to get you anywhere.
But I think the whole field would be a lot healthier is people tried to come up with their own new ideas, whether about the CC or anything else. If one is not willing to try and do this, this isn’t a good career choice and one should stop trying to be a particle theorist and find something else to do where one can make a contribution. Putting one’s efforts into an idea which obviously can’t work is just a waste of one’s time and talents, there is no justification for doing it.
> We may simply have to say that there are no viable ideas today for the theoretical determination of the cosmological constant.
OK, but if you or Peter do not want to be active it does not follow that everybody else has to give up as well.
Many decide that string theory is a good starting point for such activity, because it contains quantum gravity already (which is certainly a necessary ingredient). Others may decide that it is
better to think about causal sets, simplicial lattices, LQG or whatever.
But why should they stop doing whatever they are doing just because you or Peter feel that it is taking too long already?
(By the way, it is not 20 years. People have been working on quantum gravity for more than 70 years.)
Peter,
I am sorry, our comments crossed.
I am looking forward to read your paper.
Wolfgang,
The question of whether string theory can produce a physical prediction or not is utterly independent of what my opinion is, and needs to be answered prior to “why should anyone stop doing what they’re doing”?
Let us consider a patent absurdity to drive the point home.
If someone is proposing to compute Einstein gravity perturbatively to three loops, it is a legitimate question to ask why, what for, what do you hope to learn by it?
The question on the table is – at what point does any approach reach that level of absurdity?
Great Inquisitor,
I am quite impressed by your forthright description of the present crisis. But whereas you describe the symptoms you say little about the deeper causes. Obviously things are not that simple that some leading figures on the top decided to conspire to push a particular metaphysical fashion at the expense of more reasonable ideas.
One idea I have been thinking about is that as a result of an increasing sophistication of mathematical methods and a rapid grows of knowledge the time an individual particle theorist needs to pursue an idea and arrive at a breakthrough is perhaps longer than say at the beginning of last century. Even very intelligent and ambitious people may come into a situation where they have spend a sizable part of their lifetime with a problem without experiencing the satisfaction and joy of a significant accomplishment. Couldn’t there be a strong temptation to force a situation in which such an experience is still possible within one’s lifetime? In that case one would do everything which keeps this idea in the headlines against all ethics which the pursuit of science requires. Hegemonic control and arrogance as well as squandering, wholesale clearance of the conceptual treasures and their substitution of depth by banalizations seem to be the poisonous gift of string theorists to particle physics. Isn’t this the equivalent of Enron and World com which we are witnessing? The fact that it is not an isolated phenomenon but a general hallmark of the Zeitgeist of unleashed globalized capitalism shows that this not something which is likely to stop if Witten gets disappointed with string theory or Susskind disavows anthropic arguments.
Wolfgang
any theory of something is a reasonable alternative of a TOE. I have never seen as many interesting and deep problems in my over 40 year professional life as there are now. I even think that I am working on a very interesting one. Nobody is forcing you to do work on the lattice which you obviously consider not as a worthwhile alternative to string theory.
Dear Bert,
Thank you for your kind response. I think that you describe the temptations facing a researcher in contemporary theoretical physics very well. My take on understanding the roots of the crisis is as follows:
The time of the CREATION of grand physical theories is over, at least for a long time, after the revolutionary discoveries in the 20th century (qft, general relativity). Many young theoretical physicists enter the field in the belief that a theoretical physicist’s obligation is to discover new theories. They, and also many of the older theorists, have not learned to accept that in order to be successful, one’s success strategy must adapt to the situation in which one lives. Schroedinger, Einstein, Heisenberg, etc. are success stories of the past, and cannot serve as valid role models for a contemporary theoretical physicist’s career any longer. A string theorist’s dream is to relive this era once more.
Now is the time for the ANALYSIS of the grand physical theories discovered in the past century. None of these fields, be it quantum mechanics, quantum field theory, general relativity, solid state physics, etc, are mathematically satisfactorily understood. In fact, they are incredibly poorly understood from a mathematical viewpoint. Isn’t it baffling that after 100 years of quantum mechanics, no one has the slightest idea how to explain the simplest chemical processes mathematically rigorously from first principles ? While the theoretical physicists are missing the boat to appreciate and learn the exciting new mathematical methods available today to reach a better comprehension of the existing theories, several areas of mathematics that analyze problems in theoretical physics are nowadays booming.
Many theoretical physicists base their life on the hope to discover the holy grail of it all, the link between qft and general relativity. This is certainly a noble goal, but is it a reasonable one to build one’s career on ? It’s at least as unreasonable for a theoretical physicist to judge his/her success on his/her progress on this problem as it would be for a mathematician in the case of the Riemann hypothesis. Common sense, good taste, maturity, and modesty would forbid such a foolish and naive career strategy. This would certainly be the common viewpoint, were it not for the emergence of the miraculous genius of Witten, which has ever since tempted intelligent researchers to abandon all good judgement, and to give in to the hope and illusion of a quick answer to a big question.
The desire for a theory of quantum gravity finds some cheap gratification in string theory; it is the link to the observed world which is a problem. I have to remark here that in all this discussion of quantum gravity, one believes that gravitational waves need to exists in quantized form, and that they are not an emergent, effective phenomenon in some macroscopic limit. The dogma of gravity wave = graviton field has, as far as I know, not been really criticized. Perhaps the de Broglie principle is being taken too literally, and ad absurdum ???
While the theoretical physicists are either in despair of the absence of the last grand theory, or lost in a grand illusion, neighboring research areas are taking over, and solving extremely interesting and important problems stemming from theoretical physics. For previous generations, the natural evolution of physical theories was that they were first discovered by physicists, and when they became more mature, the mathematicians took over to manifest their true structure in all profundity. Perhaps, nowadays, theoretical physicists should take a step back, reject the sensation of a cheap miracle, and do the hard work to better understand the inner structure of the existing theories which are still as amazing as ever.
Great Inquisitor,
You may be right about what is necessary for progress, but it is not likely to happen. The least well understood part of fundamental physics is the foundations of quantum mechanics, and studying this is bad for your career. In fact, anybody who even mentions it is a crackpot.
The problem is that attempts to get a clear understanding of quantum mechanics compels one to consider philosophical questions, and physicists do not handle this situation well. They consider philosophy a waste of time, a pursuit for lesser minds, so they are overly dismissive of their opponents’ philosophical positions. It’s philosophy, metaphysics, a waste of time, not even worth taking the time to understand. So they have a communication barrier, and end up calling each other crackpots, so the field of the foundations of quantum mechanics is in some disarray.
rof:
The least well understood part of fundamental physics is the foundations of quantum mechanics, and studying this is bad for your career. In fact, anybody who even mentions it is a crackpot.
And, I believe, anybody who mentions Einstein’s relativity is a triple crackpot… So, here we go. The most fundamental problem of theoretical physics is the incompatibility of SR and QM, and we are not even allowed to think about SR and QM. When are we going to wake up?
G I,
these thoughts you expressed so clearly have been on my mind for more than a decade. But I am not quite as pessimistic as you seem to be with respect to the chance of experiencing the pleasure of great new discoveries and insights. I think that the way particle theoreticians have been trying to force this during the last decades is futile and counterproductive. Instead of being extremely caring about physical principles underlying our most successful particle physics theory and to be more imaginative about extending the range of their implementation, they do just the opposite. They are ultraconservative on the side of the implementing formalism and “revolutionary” about speculations which squander established principles and concepts in an uncontrolled way. How else could you understand the slavish adherence to a metaphoric quantization approach culminating in the formalism of functional integration which is known to be artistic and metaphoric i.e. lacks any intrinsicness? To discover something in an artistic way is quite normal and human, see the Bohr Sommerfeld old style QM. Fortunately in that case the better implementation of the evolving principles was discovered so rapidly that there was no time for a fossilation of formalism. A very good illustration of the point I am trying to get across is the discovery of the renormalization theory during the 1940ies. The principles underlying QFT were already in place, but a totally inadequate implementing formalism prevented people from extracting the correct physical results and this led to quite wild speculations which cast doubts on the principles which were already clearly formulated by the protagonists of QFT. It was only after a radical change in the implementing formalism which upheld the principles, that real progress was made.
Roughly speaking string theory is what you get if you maintain a functional setting at all costs and instead massage the principles and concepts so that they seem to describe reality within an obsolete formalism. If you have such an efficient formalism as that of Feynman, it is understandable and even reasonable to explore it beyond its range of validity, but you should never allow it to play the role of a holy cow.
To keep the revolutionary ideas away from the the principles on the side of innovative and extended implementations is difficult, in fact very very difficult. One needs a lot of time, patience, knowledge, modesty and hindsight. There are a few people who have chosen this path, most of the ones I know work in algebraic QFT (Local Quantum Physics) and I have been trying to be one of them. It is not a carrier-supportive path and if my carrier would not have been completed before I took this decision, I may not have done it.
My worry is not so much if the span of my left lifetime is sufficient to experience the joy of a genuine discovery, rather I am worried if the knowledge which is necessary to achieve that and to understand its conceptual implication will not be wiped out by the increasing addition to get hegemonic control over particle physics and the arrogant idea of making nature like a dog jump over a string. In the media you hear a lot about string theory and considerably less about LQG (which likes to position itself as the adversary in the final Armageddon over the hearts and minds of particle physics). There will be a forthcoming book by Lee Smolin but I would bet that there will be no mentioning of the ideas on that topic coming from AQFT. In fact up to now that liberal atmosphere at the Perimeter seems to have been tested by only one AQFTist and even that one (Hans Halvorson) is more involved in the study of philosophical aspects of AQFT than in the main topic at the perimeter.
The pictures emerging in AQFT about physical reality (e.g. the characterization of the full content of QFT in terms of the relative position of a finite number of copies of the “monade”, which I mentioned on some occasion) are quite startling precisely because they emerge from a totally conservative setting. But the ability to recognize, evaluate and to execute (i.e. its material basis at universities) these subtle new concepts has been significantly diminished by that banalization coming with that metaphoric way of thinking supported by string theory.
Since you mentioned the role of Witten in this process, I would like to direct your attention to the interesting fact that there was a different Witten before he was directed away from the physical beauty (see e.g. his analysis of the Kosterlitz-Thouless phase transitions in terms of infrared quasiparticle clouds) towards mathematical beauty by Atiyah. Nothing against mathematical beauty, but one should pay attention to its originating from physical beauty. Even now his role in the Maldecena “revolution” his role was relatively restraint (I think this is a residue of the early Witten) in the way a conjecture was manufactured into a fact and (after thousands of papers, I supported the various stages of this manufacturing process in an ealier blog by citations from some of these papers) became the pivotal argument why the fate of string theory is (according to Gross) inexorably linked to that of the Standard Model. Since this is a watershed (something akin but reverse to the phlogiston-oxygen change of the theory of combustion) which visibly separated the new metaphoric approach from the good old science, it may be interesting to return to this crucial event and analyze it more carefully (and without any polemics).
Dear Prof. Schroer,
> I have never seen as many interesting and deep problems in my
> over 40 year professional life as there are now.
I agree, physics is as interesting as ever if not more than ever.
> Nobody is forcing you to do work on the lattice which you
> obviously consider not as a worthwhile alternative to string
> theory.
You must have misunderstood my comment.
Recently there is some progress by people who try to put supersymmetry and superstrings on the lattice (look at papers by Kawai, Catterall an others) and I find this very interesting.
And there is still a chance that lattice gravity without
supersymmetry could work. I mentioned one example on my blog
here.
Wolfgang,
in that case there was a misunderstanding on my part. So we both agree that the world of particle physics is full of interesting and important problems (even below the challenges coming from gravity) which is a far cry from the “no other game in town” hype of stringers.
Bert,
Thank you for your clear comments and arguments.
I do agree that for a particle theorist working on approaches to QG other than string theory, everything is fine as long as he/she is self-motivated, has a job, and doesn’t mind that he/she is getting a lot less attention than string theorists (but this is true for a lot of fields in science, right ?).
Maybe there will be the next jump forward very soon in one of these alternative fields, who knows. I think that young theorists should not enter the field out of a desire to see the next revolution in their lifetime (essentially, this is already true for at least one entire generation).
I agree that the strings approach is conceptually too conservative, despite its mathematical sophistication, while other approaches are in need of more mathematical sophistication. I also agree that it would be worthwhile to push alternative theories of QG, but the proponents of those alternative approaches should pull their act together, and do something really impressive for their PR.
What the strings community has understood is that propaganda and group organization helps tremendously to get “credibility” and, more importantly, financial funding. They are a very strong political lobby in the physics community. Any proponents of a physical theory other than strings should keep in mind that in order to promote and protect themselves, they should work on building political significance, too. This is the 21st century, times have changed.
One of the questions that have bugged me for a long time is how one of the strongest movements in theoretical physics in the past could have lost so much of its influence. Why have the constructive field theorists not built a lobby as strong as that, or why did they give up their position in physics ? At the end of the 70s, they were as strong as any movement in physics ever, and despite the fact that the Wightman program might have been to rigid and narrow to begin with, there would have been myriads of alleys to build along in order to further manifest the importance of the field. However, today, this area has almost entirely vanished.
I blame it on poor political skills, and the naivety of many of its members that the importance of the field would support itself. Some constructivists have learned the language of neighboring fields, and have remained very successful. Although we are complaining about the populist practises of the strings community, we have to acknowledge that their methods are working. They are getting recognition in the public, money, etc. More purist minded physicists shy away from such practises for ethical reasons, but in the 21st century, it might very well be that every branch of science needs a lobby.
Finally, I’d like to say that many young theorists are drawn towards strings, not because of its physical beauty, but because of its mathematical sophistication. Here I’d like to comment that it is much more worthwhile in such a case to directly go into pure mathematics which is so much more beautiful than string theory can ever be.