If you didn’t follow this a couple years ago, you can read John Baez’s detailed description of the Bogdanoff Affair. For more about my dealings with them, see here,, here, and here. If you want to read their stuff, go to the website of the Mathematical Center of Riemannian Cosmology which purports to be in Latvia.
In brief, the Bogdanovs are two brothers in France with a TV show who got Ph. D.s based on work which on the whole was complete nonsense. I’m not surprised that they managed to get Ph. D.s, and one of them was failed on his first attempt. It’s not unusual in academia to be faced with having to decide what to do with students who seem to be enthusiastic and work hard, but don’t perform at an acceptable level. There are lots of reasons to just pass them with the lowest possible grade (for one thing, this gets rid of them). One of my colleagues refers to this as the “infinitely elastic C-minus”.
What was disturbing about the Bogdanov story was that they managed to get papers published in six refereed journals, some of which were quite respectable. Some of these papers were essentially identical. After this story became public, the editorial board of one of the journals (Classical and Quantum Gravity) issued a statement saying that the paper they published shouldn’t have been accepted, and that they were taking (undisclosed) steps to change their refereeing process so this wouldn’t happen again. This seemed to me strong evidence that there is so much nonsense now in the theoretical physics literature that the refereeing system has broken down. Many referees are now either unwilling or unable to identify nonsense when they see it.
I had discussions about this with quite a few physicists at the time, and many of them took the position that this wasn’t such a big deal. Their attitude was roughly that “So what if these guys managed to get something nonsensical past some lazy referees? Everyone in the community can tell that what they wrote is nonsense and just ignores it. It’s not true that we can no longer tell nonsense from serious work”. I became somewhat convinced that I was being too harsh on string theorists and others when I thought that they had completely lost the ability to identify nonsense. Maybe the only scandal here was the laziness of referees, not the infection of the whole subject by nonsense to the point where lots of people can’t tell the difference. Well, I just changed my mind, clearly at least some string theorists can’t.
I feel somewhat constrained in what I can say about the details of this, due to the fact that someone I’ve been in contact with tells me of being threatened with a lawsuit by the Bogdanovs for having criticized them publicly. I’m also not about to engage in discussion of the details of their nonsense, which is what they, like all crackpots, really want. It’s just a complete waste of time.
Funny, that last comment came from an internet address that looks a lot like the ones of Roland Schwartz and Prof. L. Yang…..
The idea that topological gravity has something to do with the full quantum gravity is a reasonable conjecture and isn’t due to the Bogdanovs. I’m sure people will keep working on it.
From my point of view, one must leave to time and history the care to decide wether this fields of research was effectively killed by Bogdanovs.
I will rather say, on the contrary, that it was born from Bogdanovs.
In his criticism of LQG Lubos states, “It assumes the metric tensor is a good variable at all distances and is the only relevent variable…it even assumes Einstein equations are more or less exact at the Planckian regime…these assumptions are challenged in a general enough theory of QG, for example all models that emerge from string theory…assumptions that have no theoretical or experimental justification”.
I agreed with these statements actually, but how come he now thinks it is ok perhaps if the above variable “the metric” has signature fluctuations in the Planckian regime, a la Bogdanov, and is a viable variable in this regime?
Even if you think TQFT has something deep to say about the initial singularity of spacetime(and who knows)the Bogdanovs have effectively killed this as a respectable research direction.
BTW the first place where Lubos signed “lumo (leashed)” was his blog entry commenting on
http://arxiv.org/abs/hep-th/0504221
Dijkgraaf, Gopakumar, Ooguri, and Vafa
Baby Universes in String Theory
that was on April 30 and in the preceding segment of that day’s blog he had said “Unfortunately, I currently do not enjoy the freedom to tell you what I think about these things.”
I tend to view Lubos protestations of tolerance for the Boganoff article as an ironical reproach to somebody who told him to ease up and stop the vitreolic attacks on other stuff. It puts him in position to say, well you told me not to be so ferocious so you must favor relaxing the intellectual standards applied to scholarship, so look what happens! I will just (to spite you) go and approve of the Bogdanoffs on the same basis that I tolerate specious research by [unnamed].
Yeah that is a tortured overinterpretation, and who cares about the adventures of Lubos melodrama, except he is entertaining sometimes. Anyway I dont take his apparent acceptance of the Bog paper at face value, it is a travesty just like the Bogs (or so I tend to suspect)
It’s interesting that Lubos is pushing “not complete nonsense” as the new standard for scientific publication, at least for certain types of physics. Of course for, say climate science, he expects a level of rigor exceeding pure mathematics literature.
I can’t help but notice a parallel with certain defenders of Bush administration foreign policy who have adopted “not as bad as Saddam” as the new standard for acceptable moral behavior.
on the other hand, Dijkgraaf is an eminently sensible choice).
a propos Dijkgraaf, he is one of the invited speakers on the programme of Loops 05 conference in October
loops05.aei.mpg.de/index_files/Programme.html
since Dijkgraaf’s public lecture in July is about black holes and time, I was reminded of his recent paper
http://arxiv.org/abs/hep-th/0504221
Baby Universes in String Theory
Abstract: “We argue that the holographic description of four-dimensional BPS black holes naturally includes multi-center solutions … This provides a concrete realization, within string theory, of effects that can be interpreted as the creation of baby universes…”
in that context I cannot imagine what he could mean by his jazzy phrase “the end of time” except that continuation through a black hole implies a branching of time which could be said to dispose of the classical single-track unitary-evolution notion and thus be “the end” of time as we have thought of it up til now. I certainly agree Dijkgraaf is a great choice (maybe “eminently sensible” could be supplemented to read “inspired” 🙂
I’d noticed that too. It speaks volumes that the organizers of this conference feel that Susskind’s pseudo-scientific nonsense is worthy of being half of the public face of string theory (on the other hand, Dijkgraaf is an eminently sensible choice).
I wouldn’t read too much into the lack of a definite program for the conference. Scheduling such a program is always difficult, with all sorts of last minute changes.
this may or may not bear on the general topic of attention-seeking and marginal science
please erase if insufficiently topical
The schedule posted for Strings 05 is still (as of Monday 20 June) almost blank, but it now lists a Leonard Susskind public lecture and two other events.
http://www.fields.utoronto.ca/programs/scientific/04-05/string-theory/strings2005/program.html
Public Talks
Saturday July 16, 2-5p.m.
Robbert Dijkgraaf U. Amsterdam
“Strings, Black Holes, and the End of Space and Time”
Leonard Susskind Stanford U.
“Cosmic Landscape: String Theory and the Illusion of Intelligent Design”
Panel discussion: The Next Superstring Revolution
Tuesday, July 12, 19:00-21:00
the conference goes July 11-16, so is only 3 weeks away. It seems curiously suspenseful on the part of the Toronto organizers that the posted schedule of talks is mostly blank (no regular talks shown, only the two public lectures.) Maybe we can take it as providential sign that Susskind’s title mentions the illusion of intelligence in connection with string theory (kidding)
I apologize if this is somewhat off topic (please delete if it does not belong), but every day I learn something new here. Matti Pitkanen wrote: “In some other summary brothers identify Big Bang singularity with a point rather than singularity analogous to the boundary of future light cone: this mistake of course appears again and again in popular literature.”
Exactly! Until recently everything I have learned has come from popular literature and that is how we are told to “visualize” the Big Bang. For someone who is not a mathematician or physicist, where do we turn for a more accurate understanding of these issues? Something more advanced than popular books (Kaku) but not as complex as the text books by Polchinski, Zwiebach, Zee, etc.., which are presented as introductions but are too complicated for someone without an advanced understanding of math.
I’m trying to work my way through Penrose’s new book and almost threw in the towel on the chapters on Manifolds and Symmetry Groups. It’s very frustrating. In the introduction he nonchalantly advises readers to feel free to skip the math. 1) I don’t want to skip the math and 2) It’s ALL math.
Between that demonstration of ignorance and Lubos’s new one, I think it is at least safe to say that on the whole string theorists don’t even know what a TQFT is.
Yeah, PW, people who don’t really understand things ought to abstain from commenting on them, don’t you agree? I also find that there are way too many people who engage in heated denunciations of certain theories and yet have absolutely nothing to suggest as alternatives. That, too, is rather feeble, is it not?
“1.These brothers are surely intelligent. They got an IQ of 200.”
That only comes out to 100 each, assuming it’s evenly split. Nothing to brag about.
Peter,
>What to do about this is a hard problem.
to this I answer : a national anonymous competition. In France this is the way the “grandes écoles” recruit their students and it put them way ahead universities. The problem is that now it is criticized also (for one thing because this system is very different from what is done everywhere else in the world).
I am not saying that this system should be considered as perfect : it selects people with very peculiar qualities. Nevertheless I do believe it is the less unfair, and I think it should be used along with more traditional academic systems in a balanced way.
Regards.
I would be happy if the discussion about Bogdanov affair could be based on real arguments rather than uneducated crackpot guesses and unjustified non-sense claims so familiar also from earlier discussions.
Thanks for Lubos for seeing the trouble for performing a real analysis of one of papers. I looked the reports about the thesis of G. Bogdanov and found that Majid gave a positive statement saying that the work was original. Brothers emphasize that they are mathematicians, not physicists. By looking the abstracts of their papers, one gets the impression that also their understanding of Riemannian geometry could be better.
For instance, look just the abstract of THERMAL EQUILIBRIUM AND KMS CONDITION AT THE PLANCK SCALE
Considering the expected thermal equilibrium characterizing the physics at the Planck scale, it is here stated, for the first time, that, as a system, the space-time at the Planck scale must be considered as subject to the Kubo-Martin-Schwinger (KMS) condition. Consequently, in the interior of the KMS strip, i.e. from the scale ℬ = 0 to the scale ℬ = ℓplanck, the fourth coordinate g44 must be considered as complex, the two real poles being ℬ = 0 and ℬ = ℓplanck. This means that within the limits of the KMS strip, the Lorentzian and the Euclidean metric are in a “quantum superposition state” (or coupled), this entailing a “unification” (or coupling) between the topological (Euclidean) and the physical (Lorentzian) states of space-time.
Brothers seem to have a rather vague view about Riemannian geometry (“the fourth coordinate g44 must be considered as complex”). Could a real mathematician really write something like this without feeling a deep pain in his guts.
In some other summary brothers identify Big Bang singularity with a point rather than singularity analogous to the boundary of future light cone: this mistake of course appears again and again in popular literature. Taking into account what brothers propose, this mistake looks strange since singularity is very much like the boundary of the future lightcone and by its metric 2-dimensionality is indeed an excellent candidate for serving as a seat of conformal (and thus also topological) field theory.
I see nothing crackpottish in idea about possibility of Euclidian and Lorentzian signatures. If space-time is identified as a 4-surface (or brane) this is an unavoidable prediction with deep implications. The idea that pre-Planck era corresponds to TQFT is also interesting. Personally I would rather view it as a phase during which the analogs of long cosmic strings dominate and string models become a good approximation.
Matti Pitkanen
Hi Deane,
I agree that through grade inflation and passing students who don’t perform acceptably the value of undergraduate degrees has been seriously debased. To a lesser degree the same has been true of graduate degrees. What to do about this is a hard problem.
In the Bogdanov case I still think the root of the problem is the failure of the refereeing system. If you look at their theses, Grichka’s is not egregiously non-sensical, and his committee passed him with the lowest grade, which was not unreasonable. Igor’s was nonsense, and his committee did the right thing the first time and failed him. My understanding was that he was told that if he could get his work published in refereed journals, he could come back for a second try. If the referees had done their job correctly, there would have been no problem.
Another unusual part of this story is that the person who agreed to supervise their work was Moshe Flato, and he died unexpectedly before their theses were completed. It’s quite possible that had he lived he would not have allowed Igor to submit such a thesis. Moshe was a wonderful, generous and extravagant man, one whom I was quite fond of, having enjoyed meeting and talking to him on half a dozen occasions or so over the years. I suspect his generosity was what led him to take on the Bogdanovs, but had he lived his devotion to good science probably would have kept something like Igor’s thesis from getting approved.
Quote:
It’s not unusual in academia to be faced with having to decide what to do with students who seem to be enthusiastic and work hard, but don’t perform at an acceptable level. There are lots of reasons to just pass them with the lowest possible grade (for one thing, this gets rid of them). One of my colleagues refers to this as the “infinitely elastic C-minus”.
Peter,
It’s about time that we professors recgnize the damage we do to ourselves and our community by doing this. It’s certainly an expedient action, but it does tremendous damage to our credibility.
It is an open secret in many places (Wall Street, for example) that a degree in mathematics— undergraduate, masters, or doctorate—even from a good school, tells you absolutely nothing about a person’s ability to use mathematics. The Bogdanov affair is only a particularly public example of something happens quite often. Is this really how we want it to be?
Some folks completely refuse to believe they’re wrong, regardless of how many times they’re hit over the head with a stick?
quantoken, do you ever tire of being wrong?
Peter:
It was easy to call the other side logically incoherent or complete idiot or things like that when they have published something that you can not make sense of. But consider that:
1.These brothers are surely intelligent. They got an IQ of 200. Admittedly they have practiced and trained for it (well, you can say that for virtually all student exams, as well). But Peter or any one try to get an IQ test score of 200. I bet you can’t. I can’t. No one I know can.
2.They clearly have spent a lot of time, energy working on the stuff. As Lubos said, all the formulas and equations they cited are correct. And they make correct references to names of people and all that.
If they have better intelligence than you, and have spent 10 years to come up with the ideas. And you have spent 10 minutes reading their stuff and could not understand it. The more plausible case is they may really have some good ideas that you are simply not capable to appreciate, versus the other possibility that they are complete idiot with 0 IQ, and that their brain can not think coherently.
Althought scientifically, all those are still nonsense regardless how the logic works. If you can not explain anything in nature, your theory is still worthless as far as science is concerned. This has nothing to do with intelligence.
Quantoken
Quantoken,
There is a difference between the Bogdanov papers and most of the string/M-theory literature. A more or less typical paper on hep-th these days starts from a set of assumptions about string/M-theory, then goes on to make various arguments and do various calculations based on the assumptions. Most of the time these arguments and calculations make sense, if you accept the assumptions. The problem is that the assumptions are incoherent and don’t really make sense.
As an example, consider the Douglas et. al. statistical counting arguments and calculations. You can definitely follow the logic of their argument and calculations, even though the starting point, a mish-mash of ideas about string theory, branes and the anthropic principle, is completely incoherent and there is no rational reason to believe that any prediction about physics can ever be derived from it.
The Bogdanov papers are different. There are huge leaps of logic from one sentence to the next, clear examples of misunderstandings of basic ideas by the authors, etc. The problem isn’t their assumptions, but that they can’t construct a coherent argument and don’t understand the technical tools they are using. This makes their papers look a lot like Sokal’s hoax paper, except that their papers aren’t (intentionally) funny.
I don’t think I’d have any problem winning a court case against the Bogdanovs (for one thing, I think I have strong cause for legal action against them since they published an intentionally mistranslated version of my words). But getting involved in something like that would be a huge waste of time. And now the fact that a Harvard faculty member is going around claiming that their papers make sense and are of value would make the whole thing much more difficult.
Similarly, I’m not going to waste time pointing out all the problems with the Bogdanov’s manuscripts. This has been done elsewhere, by John Baez and others. When people like the Bogdanovs publish papers containing wrong arguments and leaps of logic, what they most want is for someone more knowledgeable than them to take their ideas seriously and devote time to figuring out exactly what is wrong with their arguments and thinking hard about whether or not their logical gaps can be filled in. They’re lazy, convinced they are geniuses because of their vague conjectural ideas, and hoping that someone else will do the hard work necessary to turn their incoherent conjectures into something that makes sense. In this case I don’t believe it is possible to do this, and any time spent on showing this would be completely a waste.
Hello.
I think a clarification is needed here. The brothers have been harshly criticized for a very precise reason : in their last book they misquoted some people (including Peter Woit) as if they supported them, or at least as if they thought the brothers’ work were meaningful. I first pointed this ( here), then a french journalist talked about it and the brothers suited him, I just can’t imagine for what motive. I don’t know if the procedure is still on its way.
I agree with Peter that talking about this affair now only serve the brothers’ commercial interests, so I won’t make any further comment.
Best regards.
As far as I know, complaints from readers about the paper started coming in to the Editorial board of J. Classical and Quantum Gravity before the whole affair blew up, which is unusual. If the brothers are going to start sueing people now for criticising them then any sympathy that I (and other people) might have had for them is gone because this is a good way to help kill science and open scientific debate. However, I don’t see how they could realistically expect to sue someone in this way. I imagine though (or hope) that it is the ‘crackpot’ or ‘fraud’ label they don’t like and not impersonal criticisms of the work itself. This could probably be considered defamation of character and grounds for a lawsuit.
Even if there are seeds of really good ideas in their papers (which there might be) there is such a stigma attached to this whole affair now that no-one is going to continue with or explore the questions they address using the methods they suggest, even if that person(s) could develop or improve the whole approach. Do you think any career-minded person(s) is ever going to write a paper with both “topological field theory” and “initial singularity” or “KMS states” in the title and have the brothers’ papers in their reference list? Anyone doing such a thing is going to be instantly labelled crackpot. Also, I doubt any journal (esp CQG) or even the arxiv would accept it. Not that I am saying this is right but this is just the way things are.
Peter said:
“I feel somewhat constrained in what I can say about the details of this, due to the fact that someone I’ve been in contact with tells me of being threatened with a lawsuit by the Bogdanovs for having criticized them publicly. I’m also not about to engage in discussion of the details of their nonsense, which is what they, like all crackpots, really want. It’s just a complete waste of time.”
You repeated that several times. Are you really this weak-nerved that you really take such threat seriously? If they sue then let them sue. I do not see you have anything to lose just for being actually sued.
Frankly I do not see any ground for a legitimate law suit just because you discuss and criticize the content of their paper. On the contrary, the fact that you repeatly call them crackpots, without discussing any of the facts that leads you to do so, could well be used as a ground for suing you for defamation.
So just for the purpose of avoiding being sued, you should start criticizing and analysing about their papers in more details, instead of just blanketly accusing them to be crackpots.
Quantoken
Peter:
I do not think Lubos become a supporter of the brother just because he made some comments that looks fair, reasonable and balanced. He made some good points that the brother’s papers raised some important questions. A paper could be well worth publishing even if just for asking the important right question along.
On the other side I do not understand why you have to single out these brothers for some harsh criticism, at an era that 99% of academic papers can already be accorded the same evaluation: nonsense and worthless.
The whole super string business is already nonsense since it does not explain a single thing we observe in nature. Does it make the brothers’ paper more nonsense than nonsense just because the presentation of their ideas does not seem very coherent to you? Or if they present the same idea, but in a more logically coherent and more readable ways, then you would not consider it nonsense in that case? Why pick on unimportant details if the fundation of the whole thing of the whole field is already wrong and none-scientific, regardless of the mathematical details?
The whole thing started when some one thought the brothers pulled a hoax, and it should end when the brothers point out that it was not a hoax. There is nothing especially wrong or especially bad in the paper of the brothers comparing with the quality of the rest of academic papers. The brothers even excelled in asking important questions and provided novel ideas, something that Lubos praised rightfully!!!
The important matter in the status of the affair, is the fact that nowadays in the field of theoretical physics research, it is no longer possible to distinguish between a serious paper, or a hoax. You could no longer tell if some one is dead serious or if he is joking around. That is the status of affair today.
Now, my own evaluation of the brother’s work: The whole idea is total nonsense to start with, regardless of the details. But that would also apply to many of other academic papers I see. So the brothers do not deserve any harsher criticism than the rest.
Quantoken
I personally don’t find the paper terribly valuable, but I insist that its vagueness and strangeness is comparable to the vagueness and strangeness of other works about equally difficult and unknown subjects.
such as, for example?
Well, I don’t need to comment on the description “a new supporter of Bogdanovs’ brother” because Peter Woit is obviously the only person here who thinks that this description is anything else than a stupid and childish exaggerated game.
The paper is not a complete nonsense. It is a mathematically detailed clarification of a vague but intriguing idea about a very difficult subject of the initial singularity of the Universe. It is a paper whose details have been improved for 7 months or so, to say the least, to satisfy the real physicists much more than at the beginning. And the local fragments of the paper now mostly reflect the correct definitions of the mathematical concepts and their basic relations.
If Peter Woit thinks that most sentences of the paper are wrong or that the paper has no idea, then it only shows that Peter Woit is uncapable to understand any paper published after 1900.
I personally don’t find the paper terribly valuable, but I insist that its vagueness and strangeness is comparable to the vagueness and strangeness of other works about equally difficult and unknown subjects.
In all fairness, there is a problem evaluating any number of categories of doctorial level physics research, as advanced work commonly delivers raw data based on apparatus that lack a standardized metrology or operation.
The most obvious example of this is “quantum computing” work with ion traps. Because there’s not a high enough degree of consistancy (over 90%) between apparatus performance in different labs, there’s still not an established frequency standard for the time being. (I’m over simplifying). Thus only a casual review of claims or results out of a given lab are possible, strict confirmation and verification will only be possible a couple of years from now. Should doctorates be withheld in the meantime? Of course not.
Yet it’s quite obvious that given the number of labs, and the wide spread of resulting research that’s been published using standard equipment, that everyone cannot possibly be representing their work accurately (to put it gently). I think it’s probably safe to assume that a large number of phd’s given for quantum computing (ion trap) research are gifts, pure and simple. So what? By the time the dust settles (so to speak), the frauds will have moved on, the public won’t know or care, and no fuss will be made by the physicists and engineers that know.
Just because it’s clear there must be some frauds, there’s no practical way to determine the genius from the cranks as of yet, so there’s little one can do. And because one genius is worth ten cranks, the best course of action is to hold ones nose and wait. If its genius it’ll persist.
Sincerely, I am not sure if it is a Lubos trick.
Often one revise literature that is really wrong but contain one or two ideas really interesting that one would investigate in deep.
How could i know if Lubos is talking seriously or simply doing a joke?
Instead of title of this blog
Bogdanovs Gain a New Supporter
i would prefer
Does Bogdanovs Gain a New PARTIAL Supporter?
“Lubos deleted one of my comments about this on his blog, so I won’t bother writing there, but will comment here. It’s true that I did accuse him of joining the crackpots, and he has every right to delete things he considers personal attacks, but given his general style of dealing with people he disagrees with, this is kind of funny.”
Also is funny your erasing of my past post here!!
As a post doc, at a leading university, in the 80’s, I was witness to at least one PhD thesis on string theory that was refereed by well known people and approved by them, while those who actually knew something about how these theses produced realized that there was nothing new in them, and that at least one was plagiarized.
The problem at the time, was that the subject was developing very fast, there were very few experts with sufficient overview to referee every thesis, and almost all senior people simply had no clue.
I was also witness to how some leading string theorists with physics background, were totally taken by younger ones who used the jargon of algebraic geometry so heavily that no onen could tell if anything they said made sense, but one thought “It must make sense, because it’s highly unlikely that someone can make all this up”. Not true.
I realized already at that time that it’s entirely possible that someone can master the jargon of a highly technical subject and manage to produce papers that get published in leading journals, while these papers have no content whatsoever.
I would be very happy to give detailed examples with names, but I don’t want Peter Woit to be hit with legal action.
Another problem that I noticed is that, if any starts to make waves or to question the authorship and/or content of a paper by a PhD student and/or young researcher, people around him, and particularly his supervisor may not like that at all, and the person who questions things ends up being the bad guy. People just don’t want this kind of headache. They want students to graduate and go away.
Speaking of LQG, Lee Smolin posted a new response this morning in the topic, “Response From Smolin.”
Peter wrote:
“It’s not unusual in academia to be faced with having to decide what to do with students who seem to be enthusiastic and work hard, but don’t perform at an acceptable level. There are lots of reasons to just pass them with the lowest possible grade (for one thing, this gets rid of them). One of my colleagues refers to this as the “infinitely elastic C-minus”.
One of the reasons why I like to read this blog is that Peter does not pull any punches. I had a few professors in college who gave me ‘C’s that I probably didn’t deserve. I used to think they were just being generous — now I know the truth. 🙂
> You have written simplicial gravity
> papers yourself
Indeed. I am one among the many who failed
to solve the puzzle (so far).
At this point I hope that somebody will find
the solution and do not care who will find it,
Lubos, Renate or anybody else.
But I would expect that some new experimental
evidence will be needed as guidance.
Lubos attacked the CDT approach several month ago.
You can follow this link
http://yolanda3.dynalias.org/tsm/tsm02.html#20041218
for (one of) the discussions about it.
Wolfgang Beirl! You have written simplicial gravity papers yourself, if I remember. I visited your family website quite some time ago, an attractive picture of life in Bahamas.
Thanks for the link.
I wonder if Lubos will use similar arguments the next time he attacks CDT, or if he will try different.
Just one more remark.
Quantization of 2+1 gravity is possible
without super-strings and Regge-Ponzano
is an example of lattice gravity in 3d.
So, whenever Lubos rides a general attack against
LQG, CDT or other non-string approaches, check
first whether his argument distinguishes between
3d and 4d (the ones I heard from him usually do
not).
If not the argument cannot be valid …
Dear “”,
Lubos attacked the CDT approach several month ago.
You can follow this link
http://yolanda3.dynalias.org/tsm/tsm02.html#20041218
for (one of) the discussions about it.
Hi Aaron,
I remember your mentioning Ambjorn et al CDT as an interesting quantum gravity rival to string, in the other thread.
I guess in any research line there are some who are generous towards rival efforts (and permit themselves to be sincerely interested in them) and there are others who habitually attack or condescend. I value the former a lot.
my simplified model of Lubos is that whenever he talks about quantum gravity alternatives to string he will tend to attack whatever he sees as the most dangerous threat to string prestige. (clearly unfair to Lubos and an oversimplification, he would not be so amusing if he were predictable, but that’s my model)
So I am expecting Lubos to attack CDT presently, because I see it as the most threatening from his standpoint. I would not be surprised if he were getting into position.
BTW one of the CDT leaders is a woman named Renate Loll, as you doubtless know since you’ve read one or more of her papers. Apparently she and Ambjorn invented the approach in 1998—their first CDT papers are from then.
I think it is at least safe to say that on the whole string theorists don’t even know what a TQFT is.
Nice of you to generalize from two examples.
Lubos refers to Majid as “One of the co-fathers of quantum groups”. With all due respect, that’s plain silly, and shows how little he knows about the subject and how inclined he is to hyperbole.
Lubos deleted one of my comments about this on his blog, so I won’t bother writing there, but will comment here. It’s true that I did accuse him of joining the crackpots, and he has every right to delete things he considers personal attacks, but given his general style of dealing with people he disagrees with, this is kind of funny.
One point I made in my comment is that Lubos’s claim that “this is one of the punch lines that shows that they’re either pretty smart or someone helped them: the observables are replaced by homology cycles on the moduli space of gravitational instantons” is ridiculous. That homology classes on a moduli space are the observables is nothing but the definition of this kind of TQFT. He’s impressed that they can repeat the definition????
When this all happend in 2002, another string theorist circulated e-mail to his colleagues attacking John Baez and demonstrating an impressive lack of understanding of TQFT (he believed that a TQFT doesn’t depend on the Lagrangian). Between that demonstration of ignorance and Lubos’s new one, I think it is at least safe to say that on the whole string theorists don’t even know what a TQFT is.
Alejandro: It is a trick, isn’t it?
same thought occurred to me, on first reading Lubos post.
setting up to go thru the motions of applying similar criteria to
some serious work that he wants to discredit
but I would not have voiced my misapprehension
(thinking it too mistrustful on my part) except
that you mentioned it. Yes, it could be a “set up”.
It is a trick, isn’t it?
Pingback: Open System for Geniuses
Pingback: Not Even Wrong » Blog Archive » All Sorts of Stuff