There seems to be a peculiar trend going on in the particle theory community. Just about all theorists I talk to, correspond with, argue with on blogs, etc. claim to be quite unhappy with the Landscape, and insist that most of their colleagues share this view. On the other hand, all evidence is that Landscape research is becoming increasingly influential at the highest levels of the string theory community. The most prominent yearly string theory conference, Strings 07, will soon be taking place in Madrid, and titles of many of the talks there have just been announced. The largest contingent of speakers is from Stanford, and it appears likely that landscape studies will be the most popular topic at the conference, with various aspects of AdS/CFT running a close second. Just counting the number of times “Landscape” appears in the title of a talk, so far there are 4 such talks out of 31 with announced titles. Last year at Strings 06, out of about 50 talks, 2 had “Landscape” in the title. Naively extrapolating this eternally inflationary trend to the future, pretty much all Strings 1X talks should be about the Landscape…
Another indication of where the field is going is the yearly TASI summer school aimed at training graduate students in particle theory. This year the topic is “String Universe”, and several of the lecture series are about the Landscape, with two having “Landscape” in the title. Videos of the talks are being made available now, even as the summer school is going on. I learned about this from Clifford Johnson, who writes that the talk he most wanted to look at and recommends to everyone is Raphael Bousso’s on “Cosmology and the Landscape”.
Harvard’s Lubos Motl traditionally has been a landscape skeptic, but in recent months he has been writing more and more positive things about this subject. His latest posting advertises a new paper by Raby and Wingertner calculating statistics on (an extremely small piece of) the heterotic landscape.
Update: Lubos has written a posting entitled Landscape 2007 in response to this one. His point of view seems to be that although he doesn’t like the Landscape, he doesn’t have a workable vacuum selection principle, and as time goes on and no such principle is found, this makes the Landscape more and more likely to be correct. He doesn’t seem to even consider the possibility that the existence of the Landscape and the lack of a vacuum selection principle means that string-based 10/11d unification is just a failed idea. I suspect his point of view may be widely shared among string theorists, explaining the simultaneous unhappiness with the Landscape and its increasingly widespread adoption as a research program.
Have you taken into account that you may be persona non grata among Landscape researchers. Of course it may also be the case that you have become ad hoc confessor for the String Theory community, whom they go to in secret outside the group to confess their doubts and heresies. I hope you’re not abusing your position by giving them your own book to buy and read as a penance!
It’s about a year since Lubos was converted from his heresy. In his June 18, 2006, blog posting entitled Top twelve results of string theory, Lubos’ top result number 12 was:
‘The existence of the landscape, a large enough set of metastable solutions that the cosmological constant can adjust to a value small enough as to allow organized structures (which require many bits and many cycles).’
He wrote that this result was added at the suggestion of Prof. Polchinski. It’s kinda confusing to me to see the landscape hailed as a top result of string theory, something to be proud of.
Should Prof. Baez now revise his crackpot index so that it doesn’t include theories which are endlessly adjustable and so can’t make falsifiable predictions?
Could it be that everything else in string theory is just too hard to get any significant results in?
There seems to be a peculiar trend going on in the theoretical physics community. Just about all theorists I talk to, correspond with, argue with in letters, etc. claim to be quite unhappy with the theory of relativity, and insist that most of their colleagues share this view. On the other hand, all evidence is that relativity research is becoming increasingly influential at the highest levels of the theoretical physics community.
Letter from journalist X.Y. to his friend Z.V. in 1920.
(Note for the nitpicker: I do not think the landscape is comparable to relativity but merely would like to point out that the fact that a particular theory is unwelcome in scientific circles and yet it gains momentum can not and should not be interpreted as a defect.)
Peter Shor,
Yes, I think that’s basically why landscape studies are so popular. The huge variety of possible “vacua” provide a huge number of possible calculations you can do, many of which are not very hard. So, instead of trying to solve a hard problem (actually find a legitimate way to unify physics via string theory, or work on an alternative), people do this, even though it can’t ever lead anywhere. Seems pretty dysfunctional to me…
Bhabha,
“I do not think the landscape is comparable to relativity”
Than why write a comment making the analogy?
I’ll point out that my comment that most physicists are unhappy with the landscape is not my argument that there is something wrong with it. I’ve made that scientific argument at great length here and elsewhere.
Peter,
> Clifford Johnson, who writes that the talk he most wanted to look at and recommends to everyone is Raphael Bousso’s on “Cosmology and the Landscape”
this is quite different from what Clifford wrote.
“I glanced for a while at Raphael Bousso’s first lecture in the series “Cosmology and the Landscape”, and it was clear and very well presented.”
Einstein particularly despised those physicists who looked for the thinnest part of a board and then drilled as many holes as they could there.
Sounds like the problem with the landscape, string theory, toy models, etc. is that physicists are looking for something that they can calculate and publish, regardless of whether it has any relevance to the real world. That seems secondary.
Physicists need to knuckle down, think hard for years and try to solve some real problems instead of darting off to higher or lower dimensions when things get too difficult. I think they publish too much. Just pick up any copy of Phys Rev D; 99% of the theories are inconsistent with each other, so therefore 99% of them are wrong. Or not even wrong.
Wolfgang, your quotation is a bit incomplete, missing:
“(This is not entirely surprising – Raph is always an excellent lecturer.)
“This is great! I’m going to make some time to work through some of this wonderful material over the next month. Anyone else?”
wolfgang,
I exaggerated slightly, but the fact remains that the Bousso talk on the landscape was the one Clifford chose to spend his time watching, not others, and I think his comments read as an encouragement to others to spend their time watching this talk. Since Clifford is known to complain that critics emphasize too much the role of the landscape and associated pseudo-scientific argumentation in current string theory, I thought it odd that he chose to watch and recommend the Bousso talk, which is about as pseudo-scientific as these things get, rather than something else, like one of the talks on aspects of AdS/CFT, which he often complains doesn’t get enough attention.
Note: The above comment is as originally written, but it was not written as carefully as I would have liked. The clause “which is about as pseudo-scientific as these things get” was intended to refer to the advertised topic of Bousso’s series of talks, not specifically to his first talk.
OK, I’m puzzled by your count of which topics are dominating string theory (but then, I usually am). I see four titles explicitly mentioning the landscape, maybe two more that are landscape-related. That’s all. Are you counting anything related to, say, inflationary model-building as ‘landscape’?
Also:
I thought it odd that he chose to watch and recommend the Bousso talk, which is about as pseudo-scientific as these things get
I watched the first Bousso lecture: it was a very straightforward description of deSitter space, FRW cosmology, and why there is a cosmological constant problem. Things that anyone interested in cosmology should know. Are you referring to a later talk?
I wonder what Einstein would think about those who like to sit and criticsize, but who don’t ever do anything themselves.
anon,
I chose to stick to counting whether “landscape” occurs in the title to avoid issues of interpretation, as well as not knowing what will actually be in some of these talks. I’ll accept your count of 6 landscape related talks. I count 4 talks on AdS/CFT, no other single topic with more talks than this. I don’t think my characterization of the landscape as the topic with the single largest number of talks is incorrect.
I didn’t watch the Bousso talk, made the assumption that his series of talks with the title “Cosmology and the Landscape” would cover similar material to his recent papers on the subject. If the first talk didn’t mention the nonsense about the landscape, and that’s why Clifford was promoting it, my apologies to him, although I think it would have been a good idea for him to explain that the reason that it was a good talk was that it didn’t deal with half of its title.
Hi Eric,
And I wonder what Einstein would think of those who devote their energies to defending the practice of bogus pseudo-science by engaging in personal attacks on anyone who dares to point out that this is what is going on?
No, this item on the crackpot index still stands:
I’m not saying string theory is crackpot physics. Whether someone wins the 50 crackpot points depends on what claims they make for this theory.
Hi Peter,
I only point out that the people who criticize the most also happen to be those who contribute the least. In my experience, such people make noise in order to give the appearance of being relevant. I’m the not criticizing you, by the way. Generally, I have no problems with your arguments, only that sometimes your statements are too extreme, i.e. that string theory is ‘pseudo-science’ and string theorists are dishonest, etc.. You could make your points without this vitriol.
Anyway, you’re right that not too many string theorists like the anthropic principle. However, most except the reality of the Landscape. It’s just not possible to answer the vacuum selection problem right now, as your nemesis points out in his recent comments. This question will have to eventually be answered if string theory is too be viagle, and I think it’s healthy to point this out.
Best,
Eric
“Videos of the talks are being made available now,”
As always, thanks for the heads up. This bog is great!
bog = blog (Above)
Dear Peter,
You are sure of the failure of superstring theory?
I think that if the Theory of String is “very elegant” also only from the point of view mathematical, it could not be wrong completely.
I am looking forward of receiving Your answer at this my opinion.
I’m studying string theory from about seven years. You think really that the string theorist, hence also me, are visionary?
For me You are a long way off from the truth and I’m sorry that You have not again understood the beauty and the elegance of mathematical verity.
I hope that You answer at these my two observations.
I wonder what Einstein would think about those who like to sit and criticsize, but who don’t ever do anything themselves.
Quite a good point, because Einstein’s time was not completely unlike ours. It didn’t take an Einstein to see that the Michelson-Morley experiment in 1887 was problematic for ether theory, but it did take an Einstein to discover special relativity. So what would Einstein think about those who liked to sit and criticize ether theory, but who didn’t ever came up with special relativity themselves?
michele,
while you wait for Woit’s answer (which surely won’t come up until next US morning), I would like to ask you a few questions, just to warm the night up:
– why in your view is string theory such a beautiful theory? where does its beauty come from? I happen to think just the opposite, that string theory is a kind of messy zoo with no rules and principles in it, and no elegance at all.
– why should this questionable elegance be a piece of reality, if no experiment is ever going to falsify or validate ST?
– what is truth in science? You sound to me like a sort of mistic or religious when you talk about “verity” (which is not an english word by the way, maybe “truth” might work better)
– have you read Woit’s book or a wide selection of his blog entries?
Is it really important what Einstain would have thunk before 1905? Maybe he would have been too busy examining patent applications?
Einstein just went for simplicity – he got rid of the Ether altogether (which was actually not disproved by the MM experiment series) and reused the Fitzgerald-Lorentz equations to good effect:
… the introduction of a light-ether will prove to be superfluous since, according to the view to be developed here, neither will a space in absolute rest endowed with special properties be introduced nor will a velocity vector be associated with a point of empty space in which electromagnetic processes take place.
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Special_relativity.html
On the other hand, his post-GR opinions on force unification might be of more interest.
michele,
I have more questions for you. I understand you’re a young italian string theorist. Since a great deal of the string debate is on sociological issues, such as funding and student recruitment, I think these topics might be interesting:
– after seven years study, do you handle it well enough to work on it and publish?
– during these years, did you also try to take a look at alternative theories of gravity, or on advances in the mathematics of QFT, or any other subject?
– how did you get involved in ST? Did you choose by yourself or were you strongly addressed by some professor?
– when you chose, were you aware of the state-of-the-art of ST?
– did popular books such as Greene’s “L’universo elegante” have any role?
– in case SUSY weren’t to come up at LHC, would you keep studying ST? have you ever thought of abandoning the theory in case it didnt’ lead to any significant improvement, and try to study something new?
I think that is perhaps a big exaggeration suggest that string theory is completely useless.
I am sure that are many stringy inspired pieces of mathematics (with regard some sectors of string theory) that will be of great interest to mathematicians for years to come.
This is, for me, the mathematical “beauty” of string theory.
I’m not a young string theorist. I am a studious of mathematics and theoretical physics.
I think that also you have not again understood the mathematical beauty….
For matteoeo
Who are you, please?
I’m looking forward to read the answer of Prof. Peter Woit.
However, I’ve read many books of string theory (Polchinski, Green-Schwarz-Witten) and more than 500 papers concerning various sectors of string theory. I’ve also published 13 papers. I’ve “trust” in the mathematical beauty of string theory and I’m sure that the next experiments with LHC can be the confirm to it.
Message for Italian peoples
Purtroppo mi rendo conto che ci sono molte persone e molti studiosi di vedute limitate e che non hanno rispetto per quella che loro definiscono “astrattezza” della scienza matematica.
Ma chi ha fede fino in fondo verrà ricompensato degli sforzi di anni e anni di studi pazienti e sacrifici inenarrabili.
michele,
the point has been made very frequently in this blog’s threads that one should distinguish ST’s merits as a mathematical tool and as a theory of something physical. I also question the fact that the theory itself is beautiful; the study of strings has boosted a great amount of study in many areas of mathematics and of mathematical QFTs, and has revealed very beautiful truths (which are tautologies and have nothing to share with the platonic “truth” you talk about) belonging to these areas, but is ST itself a beautiful theory? I really don’t know, do strings themselves have any very simple and beautiful mathcmatical content? Maybe anomaly cancellation. Or is it just an instrument that reflects other theorys’ light?
If you distinguish among mathematical achievements and physical world description, you can also say that from the physiscs point of view ST is completely useless, since it cannot calculate anything.
LHC cannot confirm ST, since ST doesn’t predict anything hat has to do with LHC; what could happen is that LHC does not falsify it, which surely will be the case since ST is not fasifiable. as to your italian message, what stries me more is the use of the word “Faith”, which in my view shouldn’t belong to science. Will you still have faith after LHC will show no sign of SUSY?
Anyway I’ll stop posting since this is becoming a personal argument and at the moment there is no moderation. And also the topic was “anthropic landscape” rather than ST in general. Sorry Peter.
Michele,
I’ve never written anywhere that “string theory is completely useless”. String theory is a mixed bag, ranging from some wonderful mathematics to some appalling pseudo-science. This posting is about the “Landscape”, an increasingly active part of string theory research which is mathematically extremely ugly, as well as showing no signs at all of having any connection to physics. This is what I’m criticizing here as pseudo-science. If you’re interested in my views on string theory in general, there’s a huge amount of this here on the blog, and my book has just come out in Italian…
Like the host of this blog – and no doubt many others – I find Lubos’s climbdown over the anthropic principle somewhat puzzling, especially as this does not seem to be based on any new evidence coming to light. I would advance the following explanation: although the String Theory community values Lubos’s services as a cheerleader, they do, at the same time, recognise that he is a loose cannon, and have sent him to special clinic for reprogramming, a bit like Alex in A Clockwork Orange. The new Lubos, although just as hostile to critics of S.T. will now no longer resist the encroachment of anthropic arguments, or any other pseudo-science that comes his way, provided that it comes from the right sources.
Apologies to John Baez, whose comment above spent all night in the spam queue of my blog software. It gets very suspicious when people use links in their comments, unfortunately it doesn’t seem to be configurable in any way.
Chris, the anthropic landscape is the language in which God wrote the world.
Dear Peter
I would Thank You for Your advices. I’ve determined to read Your new book.
Now, I’m writing You for ask You with regard the “Loop Quantum gravity”, you think that it can be a good alternative theory as regards string theory?
I just want to point out that “verity” most certainly is an English word, one of which I happen to be rather fond.
strange, my dictionary doesn’t quote it but I see on Word Reference it exists, must be very rare. sorry for that.
michele, would You like to answer my question about faith and science?
matteoeo
I believe in mathematics and this has not a metaphysics meaning.
King ray wrote: “Physicists need to knuckle down, think hard for years and try to solve some real problems instead of darting off to higher or lower dimensions when things get too difficult. I think they publish too much.”
True. Alas, this has a cause, known as “publish or perish”. So either you pick/invent some easy problem which you can use to generate a lot of papers in a fairly limited amount of time, or you’re out of academia and need to get a Real Job(TM) to put food on the table. And then you won’t have much if any time to think about physics.
So academia ends up being populated by people doing things which they don’t really believe in, holding on to the hope that some day, they’ll end up having the time to do what they really would like to. Somehow. Someday.
Easy to criticize, but try to come up with a workable alternative.
Maybe somebody smart enough to do something really worthwile in theoretical physics should also be smart enough to become independently wealthy in a reasonable amount of time (a decade or so)? Then the best course of action might be to just fire all theoreticians and funnel the funds to experimental physics instead. An LHC is out of reach for individuals, so it can only be built using public funds. Not true of model building and theory.
Michele
“Believing” in anything for a while, is at least a temporary metaphysical act of faith.
Any social contracts to deal with something as “given”, without proof, such as commitments to axiomatics of logic, mathematics, language, etc., are all equivalent to metaphysical acts of faith. So none of us, scientist or mathematicians, should decry metaphysic “belief” too vigorously. We can’t avoid it.
But one shouldn’t loses track of the difference between metaphysical, unprovable models, and those which (although also essentially metaphysical) are able to be supported or refuted by empirical observation. Because this distinguishes scientific models, and the scientific enterprise, from most other (including mathematical) models and disciplines.
The argument to which you should try to respond is that String Theories and the Landscape currently don’t pass this test, as Science.
Thanks for pointing to the link to the TASI2007 lecture videos (via “Asymptotia”). Meanwhile I listened there to the first three lectures by Bousso on the c.c. problem, and found them very illuminating indeed. Without going into too much technicalities associated with string theory he makes a convincing point that the anthropic argument, taken seriously, is in fact not a mere tautology, and far from trivial, since it obliges to demonstrate that there are sufficiently many choices for the c.c. in the theory, and to derive from the theory a mechanism how these choices are populated in a way consistent with the observations about our universe.
Very recommendable lectures, also for non-experts.
Cheers, Fynn.
AGeek — you could be on to something there.
Bousso’s talk mostly based on his previously published papers, e.g.
http://arxiv.org/abs/hep-th/0702115
He’s basically trying to substitute Weinberg’s “observers require galaxies” with something like “observers obey the laws of thermodynamics”
What really bothers me is that, since superstring/M-theory is supposed to explain [among other things] thermodynamics as well, it’s like saying “observers obey the laws of superstrings”. This, of course, leads nowhere [at least logically].
(Correct me if I’m wrong)
Thus, it’s obvious to assume that we need some sort of a meta-theory approach, maybe similar to what we have in mathematical logic/proof theory
Peter,
A few years ago, you wrote about the Einstein issue of the Scientific American:
“One article in the magazine doesn’t really have much to do with Einstein and I believe would make him gag if he were still around. The article, entitled “The String Theory Landscape” is by Raphael Bousso and Joe Polchinski. In it they claim credit for the pseudo-scientific idea of “explaining” the value of the cosmological constant by the existence of the “landscape” and the anthropic principle. It’s sad to see this nonsense being purveyed by the most respected and well-known popular science publication in the US.”
After Joe commented on this on Jacques Distler’s blog (http://golem.ph.utexas.edu/~distler/blog/archives/000760.html), you offered an apology:
“First of all, you’re right that the tone is quite objectionable and I’d like to apologize to you for it. I sincerely regret writing that posting in that way, and you’re right to object to it. But while I agree with you about the civility issue here, I disagree with you about the issue of whether this kind of thing is legitimate scientific discussion. The example you give is a low point for my blog […]”
I am not qualified to judge the competition for low point on your blog, but the depth of your contrition is illustrated well by a more recent posting:
“I thought it odd that he chose to watch and recommend the Bousso talk, which is about as pseudo-scientific as these things get”
which, amusingly, prompted one of your readers to inform you of its content. I can’t help admiring the frankness of your reply,
“I didn’t watch the Bousso talk […]”,
but the episode tempts me to quote the question that Welch asked McCarthy. You can google it as an exercise in checking sources.
Raphael,
The only thing I regret here is that I did not express myself precisely in one of the comments I wrote, with the “about as pseudo-scientific as these things get” clause applying to your talk when I meant it to apply to the advertised topic of your lectures. I’ll add something to the end of that comment to make that clear.
No, I didn’t watch the talk, but I have read your recent papers, as well as a wide variety of other promotional material by you and others for the anthropic landscape, including your Scientific American article with Polchinski. I’m not about to apologize for referring to any of that as “pseudo-science”, since that’s what it is. I can assure you that, privately but perhaps not to your face, a large number of physicists express themselves in even stronger and less civil manner about this topic. After I apologized to Polchinski for some of the language used about the Scientific American article, I received several e-mails from people complaining to me that I had no business apologizing, since my description was completely accurate.
Many people besides me, including many of the leaders of the particle theory community, feel that what you and others are doing to (quite successfully) promote an inherently untestable research program is extremely dangerous for physics. I’m not going to apologize for forcefully making this case here.
If you think it permissible to bring up the McCarthy era as an analogy to criticisms of the cosmic landscape, you may escalate the hostilities because others will draw analogies between string propaganda and the propaganda of certain historical dictatorships, etc.
The following question in my opinion can more appropriately be directed to those who popularize pseudoscience, than to those who combat it:
‘Have you no sense of decency?’ – http://www.americanrhetoric.com/speeches/welch-mccarthy.html
well, the landscape is definitely a topic that attracts a lot of attention and very many interesting developments have been made in this field. I am presently at the String Phenomenology (this year near Rome) and we’ve just had a very stimulating talk by Keith Dienes who closed (among other things) with stating “just as in astrophysics, botany, and zoology, the first step in the analysis of a large data set is enumeration and classification” (slides not yet online, should be shortly). He made his points well, his talk was (as always) very good (as well as entertaining), and I understand the attempt of ‘That’s what we have, now let’s deal with it’ – which is imho as risky as courageous. Nevertheless I can’t avoid finding the landscape botanics somewhat depressing.
Bee,
The problem is that the landscape of supposed string vacua is NOT a “data set”. Actual data about the real world is worth spending time enumerating and classifying. Endlessly complicated and useless constructions that reflect nothing except the failure of a certain research program are not worth spending time on. The fact that this is a rather easy activity to engage in, that you can keep yourself busy for years doing it, generating lots of papers, doesn’t mean it’s worth doing.
Peter,
If you think studying string theory vacua is is not worth your time, then you definitely shouldn’t spend any time on it. However, leave the rest of us who think it’s worthwhile alone. I don’t see how it’s any of your concern what the rest of us choose to study.
Eric,
If you don’t want to hear my opinions on “string vacua” and want to be left alone to pursue their study, all you have to do is not read this blog.