This week and next there are workshops at Snowmass on the particle and accelerator physics aspects of the proposed International Linear Collider (ILC). There’s a new weekly newsletter and a new website devoted to the ILC project which has twice-daily updates from the Snowmass workshops. Kind of like blogging, except done by professionals. Soon every conference or workshop will have their official blogger (two ongoing mathematical physics ones that link to blogs on their website are at the KITP and at Oberwolfach. I really should write more about twisted K-theory here sometime….)
For more about plans for the ILC, and for a presentation about CERN’s plans for the future, see the talks from the EPP2010 meeting at Cornell earlier this month.
In other particle physics news, the RSVP project at Brookhaven has been terminated.
Update: There’s another collider physics workshop going on in the Colorado mountains, this one is at Aspen and is concentrating on LHC physics.
Peter:
This is an academic scandal related to some in the Math department of Columbia University. Since you are at Columbia, you must know the persons involved, and probably know about this incident, too. Would you like to comment on it? True? False? Your opinion?
http://www.stat.rutgers.edu/~shepp/smm.pdf
Quantoken
I’d enjoy reasding it.
BTW, I was wondering about the following, but couldn’t find the answer here in Oberwolfach:
Given a space X, its K-theory is the set of homotopy equivalence classes from X to the space of Fredholm operators [Map(X,Fred)].
One gets twisted K-theory from that by allowing these maps to really be sections of a Fredholm-bundle E associated to a PU(H)-bundle, [Gamma(X,E)].
But noting that a map is just section of a -1 gerbe and a bundle-section is really the section of a 0-gerbe, it almost seems like there is a pattern emerging here.
What would we obtain if we considered homotopy classes of sections of a Fredholm-structure associated to a PU(H)-(1-)gerbe (or a PU(H)-n-gerbe)?
(Of course I am aware that it might not be totally obvoious what an associated gerbe is supposed to be.)
Re: the academic scandal – Ma seems to have failed to acknowledge that a graduate student has no status and that putting up with shabby or perceived shabby treatment by one’s supervisor is part of the deal. Of course, when he threatened them with a lawsuit, they just closed ranks. What did he expect?
Quantoken and Chris,
This is completely off-topic and I feel highly constrained in commenting in a public forum about something that has been the subject of a court case, since the last thing in the world I would want to do is to stir up renewed litigation over this issue. So I won’t say anything about Shepp or Ma other than that my personal opinion, knowing most of the facts of the case, is that they’re the ones in the wrong here.
I can comment in more detail about Phong, who I know quite well and whose interactions with his students I’ve seen quite a lot of over the more than fifteen years I’ve been at Columbia. Phong is one of the best advisors of Ph. D. students our department has, one could easily make the case that he is the best we have. He works extremely hard at advising students, and is incredibly generous to them with his time and his ideas. He has had very many students, quite a few who have gone on to successful careers. He’s a very straight-forward guy, and the accusations made against him are highly implausible if you know him and the student involved.
The department did look into Ma’s accusations carefully, and the people who did this are also people I know well and who have high ethical standards. Repeated attempts were made to find some way for Ma to complete a Ph.D. here.
I’m afraid that’s all I can say here about this story. Please don’t post anymore about it here. It is off-topic, and I find it very frustrating not to be able to say what I think about the details of this and the people involved.
Hi Urs,
Sorry, but I can’t help you with your question, since I haven’t thought much at all about the abstract point of view that you’re asking about. The cases I’ve found twisted K-theory and gerbes useful involve specific equivariant projective vector bundles, not the abstract definition you ask about.
Peter
String theorist Lubos Motl has a new post on the beauty of using maths to fight cancer: http://motls.blogspot.com/2005/08/beauty-of-math-vs-cancer.html
It makes a lot more sense to describe useful and potentially beneficial uses of maths with emotional words, than the usual propaganda of calling useless string theory elegant/beautiful. String theorists could become cancer theorists and actually do something useful. Hopefully they will when they finally grasp that strings are a dead end, wasting time and money! It is terribly tragic that the finest brainpower in the world has been wasted for over 20 years.
Dear Nigel,
let me admit that the word “beauty” was mostly referring to something else that you had to miss.
Of course I think that the beauty of string theory is much more striking than any beauty that can be found in the models you mention; on the other hand, these models may be more useful for practical applications.
All the best
Luboš
Dear Luboš,
I am glad you are honest and admit that work in other areas are more useful for practical applications than string theory.
If beauty lies in the eye of the beholder then you are entitled to see strings like that. But my teachers told me the arts are subjective, since beauty is not really a testable scientific concept. This is because everyone sees beauty differently. But science is different, being based on quantitative facts, and no theory is worth anything until it has after survived experimental tests. This is why extra dimensions/strings cannot be viewed as science. There are other possibilities out there which are not treated as serious science because of the excessive attention on strings. Crackpot theories are crowding out some genuine alternatives to string theory because string theory itself is so hard to distinguish from a crackpot theory. One positive claim about string theory is that it has brilliant people working on it: but if you look back to the 19th century, many brilliant people worked on Kelvin’s theory of vortex atoms, which turned out to be a dead end. So mistakes happen.
Best wishes,
Nigel
Dear Nigel,
it may be difficult for you to distinguish string theory from a crackpot theory. But one should notice that it is difficult to distinguish any correct theory from any wrong theory for anyone who simply does not have a sufficient intellectual capacity to understand the relevant questions.
So unless you’re Nigel Hitchin, I highly recommend you to think about the implications of your ignorance. If you will think enough, one of your conclusions will be that you should be silent – or at least modest – about things that you have no chance to understand.
Best
Luboš
Dear Luboš,
I’m not saying mathematics is not beautiful, just that it is ugly for you to keep sounding off emotionally about string theory. Science is fragmenting because most professors are locked into one particular idea which they defend emotionally like a girlfriend!
(Is string theory really more ‘beautiful’ than Franziska Michor, who you interviewed about the maths of cancer?) Applying the term ‘beauty’ to useless string theory shows a corruption of science.
If string theory is not tangible or even testable. It is like ESP and UFOs or aliens. To use propaganda like ‘beauty’ is just missing the point: beautiful equations can be wrong.
Please be aware I studied QM and general relativity and the beauty of those theories occurs where they have been checked by experimental tests. Einstein’s views on cosmology were disproved experimentally, and his fault was pushing general relativity too far, by adding unobservables to make it model his prejudiced view of a static universe.
Luboš, I do not understand why string leaders become dictators of ‘beautiful’ speculative science, but that ignorance on my part is no reason to be silent. Any dictator can say his critics are ignorant of the hidden dimensions of his philosophy. Really, it is the not the critics who are really the ignorant ones. I’ve done some research and string theorists will not be objective enough to read it and let it be published and debated properly. It might be just as well, because they are so emotional about strings they aren’t objective.
Best wishes,
Nigel
http://news.bbc.co.uk/1/hi/education/3580742.stm :
‘There are more pupils taking A-level psychology than physics – and if current trends continue, the declining science subject will be overtaken by sociology.’
I wrote about the fall in A-level physics uptake in Britain in the editorial/opinion piece for Electronics World, Oct 03. It coincides with the rise of superstring speculation at the top. Teachers can’t do anything because nobody at the top listens, they say all critics are ignorant. At that time, the physics department of my local university, Essex, had just closed because there were too few students. All the string theorists who wrote letters in said (rudely) that Kaku’s popular string theory book sold well, so I was ignorant. But that book had no maths or physics and may have been selling to people who also like crop circles and the paranormal, and whenever pushed, Kaku tries to use Dirac’s tested equation – which is so beautiful he says it made him cry when he first saw it – to defend strings (entirely different). To have a dead end untestable theory at the top of physics sends out the wrong message to students: the whole subject seems like a dead end.
Dear Nigel,
string theory is beautiful in a different way than Franziska Michor – although it may be less different than one would a priori think. 😉 I’ve already written some texts about the beauty of string theory but let me add a few words.
String theory is beautiful because it makes the union between a diverse family of mathematical concepts and theorems inevitable. It is beautiful because all the potential inconsistencies always evolve in the right way so that all problems eventually disappear; something like that can’t happen in a generic theory that would use the same or similar fragments to do calculations.
It is beautiful because if one studies an extreme limit, any potential singularity is always smeared out and fixed by a new kind of effect, new massless modes – much like if one follows the ideal curves of an ideal lady. 😉 It is beautiful because it unifies all good ideas in physics and all good ideas are naturally melting into each other in its framework. It is beautiful because it has been the generator of new striking physical paradigms such as holography. It is beautiful because it is so incredibly unique. Your comparisons with the other “beautiful but wrong” theories are completely ridiculous. The physicists have never had a theory as beautiful as string theory, and the only thing that you may show by disagreeing with it is your ignorance.
One may sometimes be confused what a beauty of physical theories means. But if one is not confused, then it’s almost true that so beautiful theories just can’t be wrong. Your attempts to make your opinions about string theory relevant – although, as you say, your knowledge does not go beyond elementary QM and GR – are completely ludicrous.
Thanks for your understanding
Lubos
Dear Luboš,
Holography was invented by Dennis Gabor in 1947 and was not generated by ST. You are being misleading. Similarly, Witten in 1997 claimed ST ‘predicts gravity’, which is vacuous. ST doesn’t give us testable predictions like GR. Everyone knows that any real success of ST would be in the news, and it is not happening.
To give a specific example, ST cannot give any information on the strengths of fundamental forces. I’ve seen defensive, arm-waving talk that gravity must be weaker than electromagnetism because it is spread over 10 dimensions not 4, but this vague argument gives no quantitative prediction. The earliest use of extra dimensions in GR in the 1920s spilled out solutions which seemed to predict Maxwell’s equations (in tensor form) and give a unified electromagnetism-gravitational theory, but this turned out to be useless. Any unification requires an explanation of why the forces are different. The difference in strengths of weak nuclear and electromagnetism for instance is predictable from electro-weak theory, which is why that is a tested scientific theory.
ST shows no signs of being on the right lines. It has not a single tested prediction. Luboš, you are being misleading when you say: ‘It is beautiful because it unifies all good ideas in physics and all good ideas are naturally melting into each other in its framework.’
This is the sort of emotional trash you find being used by crackpots to defend nonsense. ST doesn’t unify anything properly, let alone everything. Quantitative tests are required to claim unification.
It is therefore fact, not my ignorant ‘ludicrous’ opinion, that ST is untested speculation. GR with a fluid source (Higgs field) and viewing Hubble’s law as a spacetime recession (not just recession with distance but as time past, since both are equivalent in spacetime we observe) predicts gravity quantitatively using Feynman’s pressure shielding mechanism. You demonstrate a love for ST, but that just makes it seem more crazy to most students, who see nothing but a love for mathematics detached from reality.
Best wishes,
Nigel
NIgel and Lubos,
Stop using this place to carry on this kind of argument that leads nowhere. I’ll delete any further similar comments here.