In recent years, as it has become clear that string theory can never be used to predict anything about the real world, string theorists have reacted to this state of affairs in various often bizarre ways. Tonight there’s a new review article by Steve Giddings about string theory which doesn’t even pretend that the theory will ever make a real prediction about anything. Giddings seems to think that the particle phenomenology archive hep-ph is the place to post this kind of thing, not the hep-th archive devoted to less experimentally based work. This is pretty funny, but the really hilarious thing is the way Giddings motivates string theory. In a section entitled “The problem of predictivity” he argues that our inability to make quantum gravity predictions at high energy is a problem of supreme importance, then goes on to use this to motivate the introduction of string theory, which in the end gives a theoretical framework unable to predict anything about anything at any energy.
The review does actually claim at various points that string theory “predicts” gauge theory, fermions, supersymmetry, Dp-branes, and the cosmological constant. It just neglects to mention that it doesn’t predict any characteristics of any of these things (value of the cosmological constant, any observable characteristic of a Dp-brane, how supersymmetry is broken, what kind of fermions, what gauge groups). String theory actually has nothing at all to say about even the things Giddings claims it “predicts”.
Giddings seems to be a hard core anthropist, he ends with the exciting recent insight from string theory that:
“It may in fact be that anthropic considerations fix the small relative size of the Higgs mass as compared to the Planck mass. If so this ultimately answers the question we started with, ‘why is gravity so weak?’ This is clearly a very interesting line of research, and debate continues on these and other important points.”
Actually this is only the next to last paragraph. He finally ends with the news that exp{10^120} years from now our region of the Universe will spontaneously decompactify, which he thinks is pretty kewl.
With the current anthropic nonsense exemplified by this review article, string theory has finally reached rock-bottom. It has given up any claims to being a legitimate science and has taken on the characteristics of a cult. It is long past time for those leaders of the field with any remaining scientific integrity to take a public stand that what is going on is not all right.
Perhaps this is too much ranting. My excuse would be that I’m not in the best of moods because I’ve spent my entire break between semesters being sick (don’t worry, I’m getting better). I just can’t believe the way essentially the entire particle theory establishment, including many people I have the highest respect for, continue to allow this situation to go on without public comment.
Update: Lubos Motl has news of a new, more elaborate set of anthropic nonsense coming soon from Savas Dimopoulos, Shamit Kachru, and his senior colleage Nima Arkani-Hamed (their innovation is to divide the landscape up into “countries”. I kid you not). Lubos evidently has seen this paper early, the rest of us will have to wait until tomorrow night. Even though he pretty clearly sees how unscientific this is, he has to try to find something nice to say about it since his career depends on these people. Sad to watch, actually. Postdocs and untenured people can’t take on the fight against this garbage unless they want to commit career suicide. It’s up to the tenured people. Where are they?
Further update: It seems the “countries” terminology is due to Lubos, the authors refer instead to breaking the landscape up into “friendly neighborhoods”. Which sounds even sillier than “countries”.
Yet further update: The Arkani-Hamed, Dimopoulos, Kachru paper is now available. It consists of about fifty pages of few equations and highly convoluted anthropic sorts of arguments, not about any particular theory but somehow about whole classes of theories. Kind of a meta-argument. They don’t seem to get anything at all like an actual prediction of anything out of this, the closest they get is in their conclusion about what to expect at LHC energies:
“Instead of finding a large spectrum of new particles and interactions typically needed for naturalness, we predict sparse models with few new particles and couplings, with dimensionful parameters finely tuned but close to dangerous environmental edges.”
Pretty poetic, but I think the experimentalists working on the LHC detectors are going to have trouble using that as guidance as to what to be looking for.
Anthropicy is clearly a pretty desperate strategy, but what’s a girl to do? QGr has been stubbornly resisting all sorts of attacks for 60+ years. What I object to is the string theory thought police, who seem to regard their theory as sort of a religion, and all other approaches as heresy. It’s just possible that the QGr problem won’t be solved without some new fundamental data.
Peter said:
“The problem with the quantized superstring is not that it can’t describe interesting physical degrees of freedom, but that it can describe almost anything. It’s too ill-defined for anyone to be able to show it is inconsistent, but it is increasingly clear that it is VACUOUS .”
I find it very amusing in the last word. Thanks for the humor, but string theoreticians are over-qualified languists in inventing new words:-)
ST doesn’t just describe “almost” any thing. It describes much much more than everything in the world adds up. That’s exactly the problem. When the complexity of a theory allows it to describe more than what this universe can hold, that’s no longer a physics theory since physics strictly limit itself to the observables within this universe only.
I keep seeing STers sing the praise how ST is rich of mathematics structures and how much beauty you can find within the theory, and they can’t believe that a mathematical frame work so rich in content could have nothing to do with the real world at the end.
What they don’t realize is it is exact the problem when you have a theory too rich and provides too much structure than what is needed to encompass the whole observable universe!!! It makes the whole thing “vacuous” when you realize just what an insignificantly small portion of that theory actually describes the universe 🙂
One could propose a theory living in 137 dimentions, it surely will provide even richer structures than the current 11-D string theory. It would also be more “vacuous”.
I think even a flat 4-D theory is alittle too bigger than what the universe can hold, as we already see. A theory of flat, infinitely extending 4 dimentional spacetime of precise coordinates provides more structures and information than what the actual universe holds. The result is we see a universe that is limited in size and has fuzzy coordinates. The richness of the universe is bounded by boundary, so it is described by the conditions of the 3-D boundary of the 4-D spacetime. That’s the holographic view.
Quantoken
Peter – OK fair enough, but if you can’t make a non-Abelian gauge theory from line sources I just can’t see how YM is going to work…perhaps I’ll post something to SPR about it.
-drl
Hi Danny,
Please don’t repeat the argument. I took a look again at your comment I deleted, and it still seems to me that it is about a calculation that interests you but doesn’t have anything to do with the topic of this posting (predictivity and anthropic reasoning in string theory).
I don’t think you can convincingly argue that the current superstring theory framework can’t support YM fields. The problem with the quantized superstring is not that it can’t describe interesting physical degrees of freedom, but that it can describe almost anything. It’s too ill-defined for anyone to be able to show it is inconsistent, but it is increasingly clear that it is vacuous.
Peter – the point of the comment you deleted was – I don’t even see how string theory can support Yang-Mills, much less be a TOE. I thought this was on-topic.
I will repeat the argument if you wish.
-drl
(Sorry if I resort to bad humor sometimes. Nip nip nip.)
This landspace stuff is seriously leading nowhere. Weinberg’s original paper was “OM” and had an interesting result.
I think this “landscape” business is just playing with words. Finally string theory has a lot of ground states and one doesnt know which one to pick. The best thing is that _none_ of these vacua come close to describing the real world.
Peter said:
“The only other senior person besides Gross I can think of who has spoken up about anthropism is Steinhardt. It really is remarkable to me that they haven’t gotten others to back them up publicly.”
That’s not surprising. No one could say anthropism is wrong, since it is derived from pure logic. How could we possible living on a planet hostile to life, and the planet sits in a universe impossible to create stars and planets? So it is without question that anthropic principles are CORRECT.
The only thing that can be questioned against anthropic principles, is not whether it is correct or not, but whether it is science or not.
There are things that are absolutely correct, but is not science. Science does not necessarily have to be correct, since a theory we think is correct now may be replaced by a more accurate better theory in the future. Science have to be able to make predictions of the nature to be useful, science have to provide a mean for someone to potentially disproof itself through experiments or observations. Only when a theory makes prediction that can be verified or contradicted, and when it came out such predictions are verified instead of contradicted, will that theory be considered science.
What’s being disputed, is whether anthropic principles, although correct, does it have that predictive power at all? Some think it has, some do not. I personally think it does have predictive power, but very limited and definitely does not explain things unrelated to the condition of our existence. For example it does not explain why there’s homosexuality, which is strange from the biological point of view. I would say anthropic principle is probably some sort of semi-science.
Even the widely accepted standard of what is considered science may be subject to question itself, due to the Godel theorem. For example mathmatics, 1+2=3, that’s absolutely true, it does not even provide a potential opportunity for any one to possibly contradict itself, using experiment or whatever, so, then, is it science or not if it can never be dis-proven?
Quantoken
“They think that if they speak out, it will be the end of their careers in physics.”
Hardly. I just don’t think that they care. As I said, plenty of people are perfectly content to continue working on whatever they’re working on and let the anthropic people do what they want.
The only other senior person besides Gross I can think of who has spoken up about anthropism is Steinhardt. It really is remarkable to me that they haven’t gotten others to back them up publicly.
I can’t think of many anti-anthropic folks who have spoken loudly against the anthropic deterioration on the subject, other than perhaps David Gross. Other former colleagues who are “quietly” anti-anthropic, generally won’t speak out loudly about it because they either don’t have tenure and/or they’re a postdoc with no “political” power. They think that if they speak out, it will be the end of their careers in physics.
String theory lacks its underlying geometric entanglement that would widen and flush its application through what Einstein terms as our “persistent reality.” The problem is without this extensive symmetry the theory gets stuck in a theoretical cul-de-sac; what I’m suggesting would suggest, too, that string theory be more accuratly catagorized as _Spring Theory_.
Hi Quantoken,
This web-site is not supported by public funds. Columbia University is a private, non-profit university. The computer equipment involved and the salary of the person who supports it (me) are paid for by this private institution.
This private, non-profit institution supports educational and research activities. As part of this they pay my salary to maintain the computer system, teach classes assigned to me and engage in other research and educational activities of my choice. What I produce in the course of such research and educational activities outside the classroom belongs to me. This is the standard way universities treat this sort of intellectual property. One of my colleagues has gotten extremely wealthy through this arrangement. I haven’t.
If I thought there was any doubt about the above I would move this web-site to a commercial service. This could easily be done, but I feel it naturally belongs on the university-supported web-site since it is part of the educational and research component of my job. I also believe that the university’s standard protections of the intellectual products of their academic staff ensure that there is no question about my control and ownership of this material.
The comment section is intended to allow others to participate in the educational and research activity of which the web-site is part. To the extent that people further the educational and research goals of this site, I will do everything I can to encourage them. To the extent that they damage these goals I have to do what I can to stop them. Again, this belongs to me, and I’m solely responsible for it. It does not belong to you in any way, shape or form.
For the answer to the question you ask about Feynman’s argument that a massless spin-two particle necessarily implies general relativity, see his book “Feynman Lectures on Gravitation”
Peter:
Hope you feel better now. I am sorry to see that you had to start deleting comments. But I respect that, plus it’s not my comments that you deleted.
Not wanting to be picking, but your statement is only 25% correct: “It is something that I created, that belongs to me.” It does not belong to you. The Columbia web site, plus all your research activities, are supported by public fund. The things you create while being supported by public fund does not belong to your private property.
I am in a good mode today since I just got a few patents filed today. I am the sole creator of the patents, but it does not belong to me, since I was paid salary to create the stuff. The same principle applies to you, Peter.
Also it is not completely true you created this place. People come and discuss various things in your comment section. Without that your blog would be dead water that no one wants to look at.
That said, it is still best that people would focus a little bit more on the topics. It’s hard though because in any heated debate it is commonplace that you started in one thing, and it could leads to something else totally unexpected. I think it is perfectly healthy that different opinions get exchanged this way.
Now back to the Giddings paper. One thing I have been long puzzling is string theoreticians claimed they “predicted” gravity, and I never know exactly where that came from. Giddings’s paper seem to provide some hint. Based on what I read, the reasoning goes like this:
a.String theory leads to a spin 2 mass less particle.
b.Feynman said long ago “ANY theory that describes a spin 2 massless particle must describe gravity”.
c.So super string theory predicts gravity.
Now, does any one know any thing where b. came from? Why Feynman said any spin 2 mass less particle must be associated with gravity?
Quantoken
I am extremely pissed off right now. I just deleted the last two comments, which had nothing to do with the topic of this posting, and whose authors seem to feel that this is a good place for them to go on about whatever they feel like. It isn’t. It is something that I created, that belongs to me, and that you are damaging. Don’t do this again.
Giddings’s claim (and that of the 10000 other similar string theory propaganda pieces) is not that it contains gravity and fermions. The claim is that whereas the standard perturbative quantization of the gravitational field is non-renormalizable, quantized superstring theory contains the gravitational degrees of freedom but is term by term finite in perturbation theory.
There are several problems with this:
1. It actually is not known to be true for more than two loops.
2. Even if it is, finiteness of the terms in the perturbation series isn’t enough for a finite theory. The series diverges, and conjectural non-perturbative definitions of the theory have their own problems with infinities.
Introducing fermions into general relativity is not the problem. The problem is quantizing the gravitational field. Unless you have a good argument that the work of Chen addresses this problem, please do not discuss it further here.
Since Giddings’ clain for strings boils down to; it contains both gravity and fermions, what if we create another theory that does this? Which brings me to a modest proposal.
X. Chen has just posted a double Kalusza-Klein theory on GR which supports spinors (but does not, I think, generate them) and which accounts for quantum phenomena by zitterbewegung caused by the compacted two extra time dimesions. All we need is a way to get dirac spinors defined K-K style in an extension of this theory. Then with both Em and Dirac in a unified space time we can let them interact and tune the theory to produce QED (maybe).
Now in 1933 Infeld and van der Waerden produced a theory of spinors as a sort of bundle over GR spacetime (Sitzb. Pruss. Akad. 1933, pp 308-401.) Could modern techniques unify their spinor manifold with GR via a K-K mechanism? Is it worth looking into?
Aaron, in reply to Peter’s post statement about String Theory
“… Postdocs and untenured people can’t take on the fight against this garbage unless they want to commit career suicide. It’s up to the tenured people. Where are they? …”,
you say
“… If, all of a sudden, this starts to affect hiring patterns, then maybe that’s a big deal, but I haven’t seen anything like that. …”.
Since the current String Theory movement started out about 20 years ago, it has grown so that for years the hiring/funding for theoretical particle physics has been about 90% String Theory and 10% Loop Quantum Gravity with other approaches being miniscule.
Since String Theory already has 90% of the pie, of course you “… haven’t seen anything like … all of a sudden …[effects on]… hiring patterns …” during the recent past.
You would have to look at the early part of the last 20 years to see when “anything like that” took place.
As of now, a point related to Peter’s post is that String Theory may be choking out alternative approaches and
that such elimination of alternatives may be tolerable if the dominant approach (String Theory) actually does produce realistic models, but
if the dominant approach (String Theory) is sterile, then the field (theoretical particle physics) stagnates.
Perhaps String Theorist should admit that they have had their chance.
Two decades of the smartest people on earth working on an approach with no realistic results indicates to me that the approach is unsound, otherwise all those smart people would have already announced realistic results.
It is time to let 1000 flowers bloom and try lots of alternative approaches with equal hiring/funding and see which approach
works best.
You also say
“… You want to work on that sort of stuff, you go work on it. If you don’t, you don’t. No need for bickering on the arXiv. …”.
For some of us with unconventional viewpoints (even string theory related unconventional viewpoints such as CERN CDS EXT-2004-031), it is impossible for us to engage in “… bickering on the arXiv …”
because we are blacklisted therefrom (an example being that, since I am personally blacklisted, all my recent work including the paper I just cited is barred from the arXiv).
I’m in a bad mood and I’ve finally had it. Any more comments at all like the last two will be immediately deleted. Please take off-topic nonsense like this elsewhere. I’m not going to put up with it here anymore.
Okay from the physics then.:)
At very high energies, the density of the gluons in this wall is seen to increase greatly. Unlike the quark-gluon plasma produced in the collision of such walls, the color glass condensate describes the walls themselves, and is an intrinsic property of the particles that can only be observed under high-energy conditions such as those at RHIC.
I was also given the pdf file for consideration and wanted to know if you fellows thought any revision to KK theory would have allowed a expanded view of this area I am pointing out?
Summing over all topologies?
I’ll have to add pdf in later
drl writes:
The aether investigation was honest, and physically motivated. Propagation in itself required a medium before it was known that space and time were part of one geometry, and that propagation was a primitive fact that needed no more explanation – so it’s not fair to compare the idiocies of string theory with the honest but ultimately wrong-headed search for the aether.
Wasn’t the original motivation for string theory (even if indirectly), the problem of infinities, of f = qq’/d^2 when the distance gets so small, in other words, the inherent problem of point particles in a background of space and time?
If we could rewind the clock and go back before Schwartz and Green, and before Nambu, Nielsen and Susskind, and, knowing what’s coming, prevent it, where would particle physics be now? Of course, I realize that no one can really say, but it points out something important: given that string theory is such a calamity, what’s the more reasonable alternative?
How do we know that the “honest but ultimately wrong-headed search for the aether,” a search for something that didn’t exist, isn’t being repeated again with an “honest but ultimately wrong-headed search” for the elementary particle? Remember the importance of epistemology: it’s not what we don’t know, but what we “know” that’s not so, that can really hurt us.
The apparent “idiocy” of “stringpots” should serve to warn us of this, and instead of continuously ranting about it, maybe we ought to look back to what started it all and ask ourselves why we don’t know what an electrical charge is much less a quark? If the standard model is so successful in some ways, but disconcertingly deficient in others, why is this? Could there be something that we think we “know,” an erroneous assumption that we have accepted as a fact that is doing us in?
I was referring to anthropic-types, not string theory in general.
Peter –
I suppose we can look forward to some coset argument that groups the countries into competing blocs and pacts.
“Witten, tear down this membrane!”
Trace, but verify.
-drl
Lubos, I think you should admit one thing, at least to yourself. People like myself, Woit, Lunsford, Baez, Schroer or Rovelli have never written a positive word about anthropism. The only person on your hate-list that has been close to anthropism is Smolin with his fitness landscape (which I find disturbing), but he is also the only tenured person to publicly criticize Susskind.
We all know who the landscapers are: stringpots like Susskind, Douglas, Polchinski, Dimopoulos, Kachru, and Arkami-Hamed. And Witten and Weinberg are the ones that cannot find good arguments against the AP. Draw whatever conclusion you wish from this.
Peter, as you know, I don’t plan any career and it has no implications for my statements.
“Country” is my terminology – they only use “friendly neighborhood”. 😉
I don’t think that the claims in their paper are really justified, on the other hand it is a nicely written paper with a lot of interesting technology.
“” –
The aether investigation was honest, and physically motivated. Propagation in itself required a medium before it was known that space and time were part of one geometry, and that propagation was a primitive fact that needed no more explanation – so it’s not fair to compare the idiocies of string theory with the honest but ultimately wrong-headed search for the aether.
Nor is there any resemblance of the current phase to spectroscopy before quantum theory.
The string cult is like nothing since the pre-Baconian schoolmen.
-drl
One does not have to say nice things about garbage from people on whom one’s career rests; one can simply keep silent.
This branch of physics is perhaps going through its “models of the luminiferous aether” phase. Perhaps as a proportion of published papers in the 19th century there are as many on the aether as there are now on strings.
The change is going to come from some young researcher who has found a cocoon of safety in some small obscure university somewhere, who has a good idea; and who does not hesitate to comment on the nakedness of the emperor.
Oak – HA!
Actually, the notion of countries made me think of a marathon game of “RISK!”. Watch it, Bon-Motl is attacking Kamchatka from Alaska!
-drl
This whole phenomenon makes me think of the way that stars swell up to red giants before they use up their fuel. A branch of “physics” is dying spectacularly. Eventually the hundreds of string theorists will become just a handful and they will mostly be found in mathematics departments.
Aaron –
Explain why this site has won awards. I get excited questions from friends and acquaintences about string theory all the time, and have to explain over and over again that it is total horseshit and it practitioners charlatans.
Just because you are up to the neck in sand from the other direction doesn’t mean things aren’t really bad. I honestly think the Western world is in deep shit.
-drl
Fight against them? Who needs to fight against them? You want to work on that sort of stuff, you go work on it. If you don’t, you don’t. No need for bickering on the arXiv.
If, all of a sudden, this starts to affect hiring patterns, then maybe that’s a big deal, but I haven’t seen anything like that.
Peter, about hep-ph/0501080 by Steven Giddings, you say:
“… string theory … has given up any claims to being a
legitimate science and has taken on the characteristics of a cult.
… I just can’t believe the way
essentially the entire particle theory establishment,
including many people I have the highest respect for,
continue to allow this situation to go on without public comment. …”.
There have been notable physicists such as
Richard Feynman,
who said in Davies and Brown, Superstrings, Cambridge 1988, pp. 194-195):
“… I do feel strongly that this is nonsense! …
I think all this superstring stuff is crazy and is in the wrong direction.
… I don’t like it that they’re not calculating anything. …
why are the masses of the various particles such as quarks what they are?
All these numbers … have no explanations in these string theories
– absolutely none! … ”
and Sheldon Glashow,
who said at http://www.pbs.org/wgbh/nova/elegant/view-glashow.html
“… superstring theory … is, so far as I can see,
totally divorced from experiment or observation.
… string theorists … will say,
“We predicted the existence of gravity.”
Well, I knew a lot about gravity before there were any string theorists,
so I don’t take that as a prediction. …
… there ain’t no experiment that could be done
nor is there any observation that could be made
that would say, “You guys are wrong.”
The theory is safe, permanently safe.
I ask you, is that a theory of physics or a philosophy? …”.
They have declared that the String Emperor has No Clothes,
but
they seem to be dismissed by the current physics establishment
as being dead or senile reactionaries, to be pitied for their
inability to perceive the beauty of String Theory.
I am reminded of Kipling’s Gods of the Copybook Headings
which says in part
“… we worshiped the Gods of the Market Who promised …
that Wishes were Horses …[and]… that a Pig had Wings. …
But,
though we had plenty of money,
there was nothing our money could buy …
… Then the Gods of the Market tumbled,
and their smooth-tounged wizards withdrew,
And the Gods of the Copybook Headings
said: ‘If you don’t work you die.’
… And the hearts of the meanest were humbled
and began to belive it was true
That All is not Gold that Glitters, and Two and Two make Four …”.
So it seems to me that the smooth-tongued String Theory Wizards
have historical precedent and will eventually withdraw,
but I might not live to see that day.
Lest anyone think that I am opposed to any form of string theory,
I will refer to my paper at CERN CDS EXT-2004-031
which is also available from my web pages at
http://www.valdostamuseum.org/hamsmith/E6StringBraneStdModelAR.pdf
It is an outline of a construction based on the E6 Lie algebra
and an interpretation of strings as world-lines (as opposed to
little stringy subparticles), which construction gives
concrete structures consistent with the Standard Model.
Maybe my construction is valid and realistic,
and maybe it has faults that may or may not be remediable,
but
it is interesting to me that the String Theory establishment
seems to have very little interest in serious exploration of
such a model that, although somewhat complicated,
actually might be a way to connect String Theory with
the Standard Model.
The situation in theoretical physics is indeed sad to watch. String theorists have become a kind of religious sect refusing to receive any communications from the world outside.
When string models came around 1984, two years after my PhD and the realization that PhD would not help to get support for my work, one thing looked obvious to me. 2-D space-time would soon become a convenient toy model being replaced with a realistic theory based on 4-D surfaces representing both particles and space-time in which they appear as topological in-homogenities. If a time traveller from future would have tried to convince me that after two decades people would be filling hep-th with “predictions” of a non-renormalizable theory, I would have laughed him back to the future.
In these discussions people avoid saying aloud what the real problem is: average theoretical physicist (the finger points also to me!) is full of vulnerable ego and so concentrated in optimizing the career of this vulnerable ego that he will never take a risk of wasting time by listening a person without name and position. My consolation is that I still has some years to develop TGD while looking how colleagues are getting sick of string theory. I try my best to avoid feeling some malicious pleasure and thinking that colleagues are now getting just what they deserve. Fortunately, when farce continues forever it ceases to be fun for both actors and audience and comes to an end.
Matti Pitkanen
As usual, there are no equations, no derivations, no apparatus, lots of buzzwords, etc. IOW this paper is the gradient of a crackpotential.
Moreover this person writes on a 4th-grade level. Don’t future bullshitters understand the importance of rhetoric? Where are the great teachers of our day?
-drl