Not Even Wrong

The Edge web-site has something new up they call Einstein: An Edge Symposium (thanks to commenter Hendrik for pointing this out). It’s an exchange between Walter Isaacson, Paul Steinhardt and Brian Greene, nominally about Einstein, but ending up turning into a discussion of whether and how string theory has “crashed”.

Steinhardt forcefully makes the same point I’ve made ad nauseam here: the anthropic string theory landscape is not a valid scientific research program, but simply the kind of thing you end up with when a speculative idea fails.

In my view, and in the eyes of many others, fundamental theory has crashed at the moment. Instead of delivering what it was supposed to deliver—a simple explanation of why the masses of particles and their interactions are what they are—we get instead the idea that string theory allows googols of possibilities and there is no particular reason for the properties we actually observe. They have been selected by chance. In fact, most of the universe has different properties. So, the question is, is that a satisfactory explanation of the laws of physics? In my own view, if I had walked in the door with a theory not called string theory and said that it is consistent with the observed laws of nature, but, by the way, it also gives a googol other possibilities, I doubt that I would have been able to say another sentence. I wouldn’t have been taken seriously…

But what angers people is even the idea that you might accept that possibility—that the ultimate theory has this googol of possibilities for the laws of physics? That should not be accepted. That should be regarded as an out and out failure requiring some saving idea…

What I can’t accept is the current view which simply accepts the multiplicity. Not only is it a crash, but it’s a particularly nefarious kind of crash, because if you accept the idea of having a theory which allows an infinite number of possibilities (of which our observable universe is one), then there’s really no way within science of disproving this idea. Whether a new observation or experiment comes out one way or the other, you can always claim afterwards that we happen to live in a sector of the universe where that is so. In fact, this reasoning has already been applied recently as theorists tried to explain the unexpected discovery of dark energy. The problem is that you can never disprove such a theory … nor can you prove it.

Steinhardt dismisses attempts to hypothesize that maybe the landscape is somehow predictive as follows:

Do you mean as derived from string theory? I don’t believe that’s true. I don’t believe it’s possible…

Well, I believe that if you came to me with such a theory I could probably turn around within 24 hours and come up with an alternative theory in which property X wasn’t universal after all. In fact, you almost know that’s true from the conversation that’s been happening in the field already, where someone says, these properties are universal and these others are not. The next day, another theorist will write a paper saying, no, different properties are universal. There are simply no strong guidelines for deciding…

If a version of string theory with a googol-fold multiplicity of physical laws were to be disproved one day, I don’t think proponents would give up on string theory. I suspect a clever theorist would come up with a variation that would evade the conflict. In fact, this has already been our experience with multiverse theories to date. In practice, there are never enough experiments or observations, or enough mathematical constraints to rule out a multiverse of possibilities. By the same token, this means that there are no firm predictions that can definitively decide whether this multiplicity beyond our horizon is true or not.

After some prodding, Steinhardt makes clear that he is not claiming that string theory as whole has crashed, that it is just the landscape that is the crash. While insisting that people need to acknowledge that the landscape is simply a scientific failure, he holds out hope that some fix to string theory may still be found:

…it’s that point of view which is a crash, and needs a fix. I am not arguing that string theory should be abandoned. I think it holds too much promise. I am arguing that it is in trouble and needs new ideas to save it.

There’s also some discussion about what Einstein would have thought of string theory and the landscape, with Steinhardt of the opinion that Einstein would have liked string theory with its unification via geometry of extra dimensions, but that he would have rejected the landscape:

Einstein took gravity and turned it into wiggling jello-like space, and now string theory turns everything in the universe, all forces, all constituents into geometrical, vibrating, wiggling entities. String theory also uses the idea of higher dimensions, which is also something that Einstein found appealing.

What I was commenting on earlier was where the string program has gone recently, which I described as a crash. I can’t say for sure how Einstein would view it, but I strongly suspect he would reject the idea.

Three years ago I expressed the opinion that the promotion of the anthropic landscape would make Einstein gag, which so upset Joe Polchinski that he used this to argue that trackbacks to my blog should not be allowed on the arXiv (even though this was not about an arXiv paper, but a Scientific American article). At one point I regretted having used that expression, feeling it was somewhat over the top and inappropriate. In retrospect, seeing what has happened over the past three years, I’ve changed my mind. The kind of thing that would make Einstein gag has moved from popular science articles to regular appearance in the lectures and scientific articles of leading figures in particle physics. This would probably not just make him gag, but send him into a serious fit of depression.

Yesterday a new web-site was launched by the DOE and NSF, called US/LHC, which will be devoted to the role of the US in the LHC project. Besides news and descriptions of the science and the experiments, it will also include blogs by several physicists involved in experiments at the LHC. This new web-site joins several other similar ones, most notably one devoted to the ILC, and an umbrella one for US particle physics called Interactions.

I’ve sometimes wondered whether this huge publicity onslaught for the LHC is a good idea. Just as this new web-site is coming on-line, I’m starting to hear unconfirmed reports of possible very serious delays in the LHC startup, ones which may push back the beginning of experiments by a year or more. The current schedule includes no extra time for cooling down sectors of the machine which have to be warmed up to deal with one problem or another, and this cooling is a tricky months-long process. If these rumors turn out to be true, this will be good news for the Tevatron, which will have the energy frontier to itself for longer than expected. But it will definitely be very bad news for CERN and for particle physics in general, both of which have just about all of their eggs in this heavily publicized basket.

Update: From the comments here and e-mail I’m getting, it appears that others are hearing these same rumors: the first physics runs are likely to be in 2009, not 2008, due to problems that have shown up as they have started cooling down some sectors of the machine.

Update: Peter Steinberg at the US/LHC site blogs about the conundrum of whether he should be dealing with “gossip from unverified or anonymous sources”, and decides he’d better not. I suspect one consideration is that his blogging role puts him in a sort of unofficial spokesman capacity, which is rather incompatible with rumor-mongering. On the other hand, I don’t have this problem…

An informed commenter reports in the comment section about details of some of the problems that have cropped up in the last month, and that the “best guess” for the delay that these will cause is about two months. This would move the start of a physics run from next July to next September.

Update: Via the Resonaances blog, here’s the video of a September 13 colloquium talk by Lyn Evans about the LHC commissioning. Evans describes in detail two of the problems that have shown up that motivated some of the rumors: leaks that have appeared during the first cool-down of certain sectors of the machine, and problems with some of the plug-in modules that interconnect the magnets. It remains unclear if these problems will cause slippage in the schedule, and if so, how much. News about what is going on with these problems is posted here.

Despite my abusive treatment of his article Stringscape here recently, Matthew Chalmers was kind enough to send me a copy of the September issue of Physics World, which contains three shorter pieces about string theory (available on-line only to subscribers).

One of the articles is by Fred Goldhaber and entitled Scientific faith put to the test. It’s a scathing attack on the anthropic string theory landscape program, describing it as “antiscience” (rather than my favorite, “pseudo-science”). Goldhaber characterizes this sort of research as “antiscience of the left”, with its adherents promoting the idea that we can’t ever understand some things since they are due to chance. He contrasts this to the “antiscience of the right”, which promotes the idea that we can’t understand things because they come from supernatural origin, and finds both attitudes equally unscientific. As for where antiscience comes from, he has this to say:

On the left, I think that it stems from arrogance (“If I can’t figure it out, no-one ever will”). On the right, I think it comes from defensiveness (“If science is right, religion must be wrong, and that can’t be”). In the end, antiscience on both side boils down to vanity. While we need to stay alert for the vanity of those advocating antiscience, we also should guard against vanity in the name of science.

He ends on a more optimistic note, writing that he does see a difference in those on the “left”. They remain physicists, and if someone finds a “promising route to picking out the right solution to string theory”, they would leap to pursue it. He doesn’t speculate on what they would do if someone shows that string theory just inherently can’t ever predict anything…

Philosopher of science Steven Weinstein has a piece with the title Philosophy pulls strings, which tries to make the case that string theory is leading to some new interaction between physics and philosophy, since it “forces us to tackle issues that cross both disciplines.” As far as one of his topics goes, the anthropic pseudo-science, the main role I see for philosophers is to forcefully point out to the scientists involved that they are doing something intellectually highly disreputable and should stop. He also discusses a much more non-trivial and interesting topic, that of the philosphical questions about space and time raised by quantum gravity, a subject where philosophers may or may not end up having something quite useful to contribute.

Philosphers Nancy Cartwright and Roman Frigg contribute a very interesting article about how scientific theories are evaluated, entitled String theory under scrutiny [available here, thanks to commenter “R” for pointing this out]. The make the important point that immediate experimental testability of a theory is not all there is to deciding whether something is science or not. When scientific ideas are new, they often are not understood well enough to be able to extract definitive predictions from them. Theorists are generally engaged in research programs, the end result of which is supposed to be something experimentally testable. In order to evaluate a research program, you can’t just note that it isn’t predicting anything, you have to evaluate its prospects for reaching its stated goals. They describe good research programs as “progressive”:

Good research programmes are those that are progressive, i.e. those whose theories get better and better, even if individual theories face serious difficulties at certain times.

The fundamental problem with string theory is that, as far as its central goal of unifying physics goes, over the last nearly 25 years it has not only not made any progress toward explaining anything about particle physics, but, quite the opposite. Everything that has been learned about string theory makes it more and more clear that the original hopes for getting unification this way were just misguided and can’t work. The derivative here is the wrong sign.

There are areas in which string theory has had successes, notably in mathematics and in strongly-coupled gauge theories. But these are really different research programs, and the fact that progress has been made in them doesn’t change the facts about the colossal failure of the unification program. Cartwright and Frigg try and put various other “dimensions” on the string theory research program, including that of “elegance and simplicity”, writing that:

Radical string critics would then conclude that string theory is progressive only in the dimensions of elegance and simplicity (in the sense that the theory only contains one class of basic objects – strings – from which all the basic particles and forces follow), while being largely stagnant in the other dimensions.

As a “radical string critic”, I don’t see things this way. According to M-theory, “string theory” is not a theory of “one class of basic objects”. Strings are just part of a hugely complicated picture, one which at the moment is neither elegant nor simple. String theorists hope that there is some elegant and simple underlying theory, but they have not been able to come up with it despite a huge amount of work. Whatever underlies M-theory, it may be something very complicated. Perhaps M-theory is just a rather obscure corner of a story very different than what string theorists are hoping to find, one that may tell us some interesting things, but just doesn’t have anything to say about how to unify particle physics.

It seems that if you’re a Fields Medalist, you now have to have a blog. The latest of these is a new blog from Timothy Gowers. His blog will also function as a blog for the upcoming Princeton Companion to Mathematics that he is editing, and he has started a discussion about the possibility of a wiki devoted to “mathematical tricks”.

Rigorous Trivialities is another new mathematics blog, one of the rare ones not being run by a Fields Medalist.

Mathematics will now have its own “rumor mill” to gather information about job searches, to be called the Mathematics Job Wiki. It appears to have been set up by Greg Kuperberg, “who however recuses himself from handling confidential e-mail and is not the wiki moderator”. All we are told about the moderator is that “someone without a current tenure-track appointment will read e-mail sent to the Wiki Moderator.”

Gerard ‘t Hooft has translated his lecture notes on Lie Groups and Physics from Dutch into English, increasing by about two orders of magnitude the number of people who can read them.

Math and physics geeks are now certifiably cool, as the TV show Numb3rs goes into yet another season, and is joined by The Big Bang Theory. New York magazine got together a group of Columbia physics grad students to take a look at the show and discuss.

The early history of string theory is getting lots of attention these days, especially because of a conference on the subject last May. Some related articles have now appeared on the arXiv, from Di Vecchia and Schwimmer, Ramond and Schwarz. At Caltech, an Oral Histories project has made available the transcript of a long interview with Schwarz.

Hendrik, a commenter here, pointed out that there’s more of the latest string theory hype concerning results from the MAGIC telescope, originally discussed here. Now New Scientist has weighed in with an article entitled Finally, a MAGIC test for string theory? According to the article, Mavromatos and collaborators say that their (non-critical) string theory model “predicts the 4-minute delay exactly”. Polchinski is quoted to the effect that this would falsify (critical) string theory. LQG is completely cut out of the deal, with no mention of it at all. They really need to do a better marketing job. The way things are now, any supposed evidence of quantum gravitational effects is automatically evidence for string theory, in one version or another.

For the latest attempt to market string theory to astrophysicists, see this new article on astro-ph. The abstract begins not by acknowledging that string theory can’t make any predictions about cosmology, but by claiming instead that the problem is

Attempts to connect string theory with astrophysical observation are hampered by a jargon barrier, where an intimidating profusion of orientifolds, Kahler potentials, etc. dissuades cosmologists from attempting to work out the astrophysical observables of specific string theory solutions from the recent literature.

Update: Slashdot has a thoroughly worthless article about this last paper, based on the New Scientist article about it.

It appears that the release of the French edition of Lee Smolin’s book (entitled Rien ne va plus en physique ! : L’échec de la théorie des cordes) has stirred up quite a lot of attention to the string theory controversy over there. A correspondant wrote to tell me that this month’s edition of the French popular science magazine La Recherche has the controversy over string theory on the cover (La theorie des cordes dit-elle le vrai?) and four articles on the subject inside. Unfortunately I don’t have a copy of the magazine or on-line access to the articles, but just to an English language summary. It’s hard to tell from this exactly what’s in the articles. One of them is an interview with the historian of science Peter Galison, who seems to describe string theory as having “initiated a new way of seeing, crucial for the future of physics.” No idea what that is about, but I hope it’s not about the string theory landscape….

The string theorists of the Paris region have a web-page, which recently has acquired a defensive section about La faillite de la theorie des cordes? It encourages people to read Polchinski’s review of my book and Smolin’s (my response to this is here), as well as papers critical of LQG. The same web-page also has links to other information sources about string theory, including to two blogs. Personally I don’t think Jacques Distler’s blog is much of an advertisement for the subject, but sending people to Lubos Motl’s is a pretty funny thing to do….

Plagiarism Scandal

Today’s Nature has an article by Geoff Brumfiel with more details on the plagiarism scandal described here. At last count it involves 15 authors, 67 papers on the arXiv, of which about 35 were refereed and published, in 18 different journals. The arXiv has set up a special page with information about this. As far as I can tell from checking a few examples, most of the published papers are still available online at the journals, with no indication of their plagiarized nature. One exception is the plagiarized paper at JHEP, which has now been removed, with the notation

This paper has been removed because of plagiarism. We regret that the paper was published.

As far as I know, neither JHEP nor any of the journals has given any indication of an intent to change their refereeing procedures because of this scandal.

Journal of K-theory

The editors of the new Journal of K-theory have issued a public statement, explaining in detail their plans for how to handle papers submitted to the older journal, K-theory, where they had resigned as editors.

There are yet more hep-th articles on the anthropic principle this week, following recent ones devoted to the implications for fundamental physics of the heights of giraffes and sizes of brontosaurus brains. The TASI summer school designed to train particle theory graduate students this year featured talks by Raphael Bousso expounding the anthropic landscape pseudo-science as a “solution” to the CC problem. His lecture notes are now available. In them he does refer to one problem that plagues this subject, that of how to identify the intelligent observers whose probability of existence everything depends on:

The problem of characterizing observers, especially in vacua very different from ours, remains challenging.

Last night a new paper on this subject appeared on the arXiv, by Maor, Krauss and Starkman, making the point about anthropic arguments that:

arguments of these sort (see for example [3] [reference is to papers by Bousso]) strongly rely on the assertion that we must be typical observers, an assertion without sound fundamental scientific basis at the current time.

The authors end with a conclusion about what you can learn from anthropic arguments:

Finally, the correlations illuminated by anthropic reasoning imply that what we ultimately learn from anthropic arguments is that the existence of us and the existence of the observed value of Lambda do not contradict each other. That is nice, but hardly surprising.

In their acknowledgment section they thank Bousso for “lively discussions”. He thanks lots of people in his acknowledgments section, but not them. I don’t know about this question of intelligent life in other pocket universes, but the question of whether there’s intelligent life on hep-th these days seems to still be open.

The September issue of Physics World is out, featuring a 13 page advertising supplement for string theory which is pretty much unadulterated hype. The same issue includes an editorial which takes the point of view that the only problem with string theory is that:

String theorists need to do much more to explain their field’s genuine links to experiment

String theory’s lack of falsifiability is minimized as a problem, and the fact that it “raises several philosophical issues, such as the role of anthropic reasoning” is listed as a point in its favor. As for those who complain that string theory predicts nothing, in particular nothing about what will happen at the LHC, they are told to just shut up:

With CERN’s Large Hadron Collider (LHC) due to switch on next year, now is the wrong time to slam string theory for its lack of predictive power. While not able to prove string theory is right, the discovery of supersymmetric particles at the LHC would give it a major boost…

The fact that string theory doesn’t predict supersymmetry visible at LHC scales is actually acknowledged in the advertising supplement by Kachru and Susskind.

The few quotes from string theory skeptics allowed seem chosen to be those that put string theory in the most favorable possible light (except for Phil Anderson, who is reduced to hostile spluttering by Polchinski’s claims that string theory may explain high T_c superconductivity). This allows the editorialist to conclude:

However, the richness of string theory that has become apparent in the last decade, and its increasing contact with the real world, gives theorists something to shout about. This is why our main feature on the subject, which started with fairly modest intentions, has ballooned into the longest ever to appear in Physics World. As the views of even many non-string theorists in the article make clear, the theory still holds all the potential it ever did to revolutionize our understanding of the universe.

The critique of string theory by Smolin and myself is pretty much completely ignored or dismissed, with Susskind quoted as having come up with a new insulting term for us (to him we’re “Smoit”, evidently he likes that better than the “Swolin” favored by those in Santa Barbara). The claim is made that

few string theorists think that the sometimes negative portrayal of string theory in the popular arena recently has had much of an effect other than to irritate people.

Amidst the endless misleading hype contained in the Physics World piece, there’s some that simply is demonstrably completely untrue. The most egregious example might be the discussion of Witten’s Fields Medal which claims that it was awarded him due to his work on string theory compactification spaces:

.. with the study of 6D “Calabi–Yau” spaces making Witten in 1990 the first physicist to be awarded the prestigious Fields Medal

The quotes from Witten himself don’t include any of the hype about connections to experiment. He describes string theory as something very poorly understood, with even the fundamental equations of the theory unknown, and no good ideas about how to find them, leading to the danger that even if his vision is correct, realizing it may just be too hard:

It’s incredibly rich and mostly buried underground. People just know bits and pieces at the surface or that they’ve found by a little bit of digging, even though this so far amounts to an enormous body of knowledge… There is an incredible amount that is understood, an unfathomable number of details. I can’t think of any simple way of summarizing this that will help your readers. But despite that, what’s understood is a tiny, tiny amount of the full picture.. One of the greatest worries we face is that the theory may turn out to be too difficult to understand… [about the search for equations for string theory] This is certainly a question that interests me… but if I don’t work on it all the time, it’s because it’s difficult to know how to make progress.

Unlike Witten, many of the other string theorists quoted seem to have no problem with issuing streams of highly misleading hype claiming “predictions” of string theory. For instance, from David Gross:

String theory is full of qualitative predictions, such as the production of black holes at the LHC or cosmic strings in the sky, and this level of prediction is perfectly acceptable in almost every other field of science,” he says. “It’s only in particle physics that a theory can be thrown out if the 10th decimal place of a prediction doesn’t agree with experiment.

I don’t know how to characterize this kind of claim that string theory is as predictive as other scientific theories, just not able to get accuracy to 10 decimal places, as anything other than out-and-out dishonesty. If someone could come up with a legitimate, distinctive, testable prediction of string theory that gave even the correct order of magnitude for some experimental result, that would be a huge breakthrough.

Michael Green, while describing the landscape and its potential to allow for a small CC as “an enormous success” for string theory, is one of several string theorists characterizing the status of string theory as being just as good as that of QFT, with the landscape not a real problem at all, just a “supposed” one:

This supposed problem with a theory having many solutions has never been a problem before in science.

Several people promote the anthropic point of view, with Susskind describing it as the third superstring revolution, one that is even more of a revolution than the others. Polchinski adds

In terms of changing the way we think about the world, the anthropic landscape is certainly as big as the other revolutions

while Susskind’s colleague Shamit Kachru is described as “in the middle”, sensibly pointing out that it would have been a stupid thing for people to do, once they realized that the ratios of sizes of planetary orbits were environmental, to start claiming that “there is a deep anthropic lesson to be learned from Newtonian gravity.”

All in all, I think that the picture the Physics World article presents of the reaction of leading string theorists to the failure of the superstring unification project is a depressing one. Instead of acknowledging in any way this failure and considering what can be learned from it, on the whole they seem to prefer to abandon science for anthropic pseudo-science, to spout misleading claims of bogus “predictions” of string theory, and make indefensible claims that the lack of predictivity of string theory is not unusual for a science.

On the other hand, among string theory skeptics, I fear that the attitude of Howard Georgi is all too common:

I have been critical in the past of some of the rhetoric used by string-theory enthusiasts,” says Howard Georgi of Harvard University, who coinvented the supersymmetric extension of the Standard Model in 1981. “But I think that this problem has largely corrected itself as string theorists learned how complicated string theory really is. I am concerned about the focus of young theorists on mathematical details, rather than what I would consider the real-world physics of scattering experiments, but with any luck the LHC will take care of that by reminding people how interesting the real world can be.”

The problem with string theory is not too much mathematics and a lack of effort towards making connection to real world experiments, but that it is a wrong idea about unification, and thus cannot ever explain the standard model or predict what lies beyond it. The recent move among string theorists to hype bogus claims about connections to experiment, abandoning the search for greater mathematical insight into string theory as just “too hard”, retooling themselves as more salable “string phenomenologists” and “string cosmologists” is not a healthy trend. It is based on adopting the Susskind-Polchinski “multiverse” revolution in the received wisdom about how to do fundamental physics, slowly turning a once great subject from a science into a pseudo-science.

Update: Lubos is beside himself with glee over the Physics World article, see here and here (don’t miss the photo-shopped “Smoit” graphic of me and Lee Smolin). For something more reasoned, there’s a short piece at Wired.

All sorts of schools and workshops occurring this summer have been putting up materials from the talks on-line. Sometimes this is just an audio recording of the talk, which can be very frustrating if you’re interested in the details of a subject, leaving you desperately trying to guess what symbols on the blackboard correspond to the scratching noises and words from the speaker that you are hearing. Best is a set of slides used by the speaker, together with audio or video of the full talk. Some examples worth looking at include: