I have a long-percolating post that I hope to finish soon (when everything else is finished!) on “Why String Theory Must Be Right.” Not because it actually must be right, of course; it’s an hypothesis that will ultimately have to be tested against data. But there are very good reasons to think that something like string theory is going to be part of the ultimate understanding of quantum gravity, and it would be nice if more people knew what those reasons were.
Of course, it would be even nicer if those reasons were explained (to interested non-physicists as well as other physicists who are not specialists) by string theorists themselves. Unfortunately, they’re not. Most string theorists (not all, obviously; there are laudable exceptions) seem to not deem it worth their time to make much of an effort to explain why this theory with no empirical support whatsoever is nevertheless so promising. (Which it is.) Meanwhile, people who think that string theory has hit a dead end and should admit defeat — who are a tiny minority of those who are well-informed about the subject — are getting their message out with devastating effectiveness.
The latest manifestation of this trend is this video dialogue on Bloggingheads.tv, featuring science writers John Horgan and George Johnson. (Via Not Even Wrong.) Horgan is explicitly anti-string theory, while Johnson is more willing to admit that it might be worthwhile, and he’s not really qualified to pass judgment. But you’ll hear things like “string theory is just not a serious enterprise,” and see it compared to pseudoscience, postmodernism, and theology. (Pick the boogeyman of your choice!)
One of their pieces of evidence for the decline of string theory is a recent public debate between Brian Greene and Lawrence Krauss about the status of string theory. They seemed to take the very existence of such a debate as evidence that string theory isn’t really science any more — as if serious scientific subjects were never to be debated in public. Peter Woit agrees that “things are not looking good for a physical theory when there start being public debates on the subject”; indeed, I’m just about ready to give up on evolution for just that reason.
In their rush to find evidence for the conclusion they want to reach, everyone seems to be ignoring the fact that having public debates is actually a good thing, whatever the state of health of a particular field might be. The existence of a public debate isn’t evidence that a field is in trouble; it’s evidence that there is an unresolved scientific question about which many people are interested, which is wonderful. Science writers, of all people, should understand this. It’s not our job as researchers to hide away from the rest of the world until we’re absolutely sure that we’ve figured it all out, and only then share what we’ve learned; science is a process, and it needn’t be an especially esoteric one. There’s nothing illegitimate or unsavory about allowing the hoi-polloi the occasional glimpse at how the sausage is made.
What is illegitimate is when the view thereby provided is highly distorted. I’ve long supported the rights of stringy skeptics to get their arguments out to a wide audience, even if I don’t agree with them myself. The correct response on the part of those of us who appreciate the promise of string theory is to come back with our (vastly superior, of course) counter-arguments. The free market of ideas, I’m sure you’ve heard it all before.
Come on, string theorists! Make some effort to explain to everyone why this set of lofty speculations is as promising as you know it to be. It won’t hurt too much, really.
Update: Just to clarify the background of the above-mentioned debate. The original idea did not come from Brian or Lawrence; it was organized (they’ve told me) by the Smithsonian to generate interest and excitement for the adventure of particle physics, especially in the DC area, and they agreed to participate to help achieve this laudable purpose. The fact, as mentioned on Bloggingheads, that the participants were joking and enjoying themselves is evidence that they are friends who respect each other and understand that they are ultimately on the same side; not evidence that string theory itself is a joke.
It would be a shame if leading scientists were discouraged from participating in such events out of fear that discussing controversies in public gave people the wrong impression about the health of their field.
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Wow! Great!!
You killed the thread. Someone needs to say something provocative or we’ll never beat Hank Aaron’s record.
String theory is the devil!!!!
I think that’s on the right track; it just needs a little tweaking:
Not only does god exist, but so does the devil. String theory is the invention of the latter.
Dear all,
I think this was (is) a very nice thread with good discussions on some specific issues. There are certainly various matters we can further discuss. Eg Lee’s (409) comment following Mark (302) and the issues of landscape, anthropic principle, time, are we typical?, and isn’t it premature to discuss these issues at all. We can slao have a look at falsifiability again. Remember – before the notion of falsifiability, there were various notions of “verifiability” which were dominant in philosophy of science. And on the more technical matters, if somebody can explain what are the technicolor methods that Mark refers to this can be great.
“Someone needs to say something provocative ”
We can also talk about the tendency for provocation and extreme views which is quite common also in this debate.
And who is Hank Aaron? Any family relation, aaron?
Hank Aaron was a baseball player who currently owns the record for most career home runs. His record should be broken this year by Barry Bonds.
Back to string theory, does anyone know if it’s possible to stabilize all of the moduli without using fluxes, even for a special case? I think fluxes are ugly and give us the landscape, which I personally don’t like.
Re 505, I think the proper conclusion of the thread is:
“God exists since string theory is true, and the devil exists since we will never be able to test it.”
(originally said by Andre Weil on the consistency of mathematics, I’ve replaced “prove” with “test” which seems more adequate here.)
> I think the proper conclusion of the thread is:
“God exists since string theory is true […]
I am not convinced that Sean would like your conclusion 😎
“Someone needs to say something provocative or we’ll never beat Hank Aaron’s record.”
Ok, how about this:
String theory = alchemy
Newton devoted himself to alchemy, Witten to string theory…
Discoveries made in the pursuit of alchemy turned out to be useful in chemistry;
discoveries in the pusuit of ST might be useful for heavy ion physics…
Btw, what is Hank Aaron’s record?
Actually, the nice thing about this thread was that it was not provocative, and instead rather nice and modular. For example, the word “string” is mentioned only a handful of times in the recemt 50-comment interesting discussion on renormalization. Another novel thing was Mark looking and commenting om Thomas Larsson’s theory. (I always hoped somebody will do it.) There are plenty of things we can discuss (e.g., beyond my previous suggestions also we can discuss “skepticism” in general and in this case.)
The thread that wouldn’t die!
Wikipedia to the rescue for Gina’s questions:
http://en.wikipedia.org/wiki/Technicolor_%28physics%29
http://en.wikipedia.org/wiki/Hank_Aaron
Now, if we could only get Lee to post his latest screed here, we’d easily make it!
Dear all,
As for topics for discussion here are two which are related to our discussion and yet we can explore without even mentioning the S-word.
1) Symmetry: Is symmetry what it’s all about or perhaps just a cheap mathematical trick.
(Of course, there are many possibilities in between)
This is a very interesting issue on which I suspect that Peter Woit and Lee Smolin sharply differ. Peter sees, as far as I can tell from his book, that symmetry is in the essence of things and he gives an unflattering description of physicists (from the pre-QCD bootstrap time,) that dared thinking otherwise. Lee , on the other hand, has an interesting lecture called “against symmetry” that plato linked and referred to in #429.
2) Time: Given a movie or a musical symphony played on a crooked video tape or audio tape. How can we find an “correct” internal clock for the piece?
Perhaps there are known methods that engineers already use? This can help if we want to define time as an emergent feature.
Aaron: “Now, if we could only get Lee to post his latest screed here, we’d easily make it!”
Dear Aaron, Any comments by Lee will be most welcomed, as he makes a lot of interesting contributions and in a gentle style. It looks that you like Peter but not Lee, why is that?
The only thing worse than a string critic without alternative ideas is a string critic with alternative ideas.
Dear Aaron, Any comments by Lee will be most welcomed, as he makes a lot of interesting contributions and in a gentle style. It looks that you like Peter but not Lee, why is that?
I think I’m going to take a break from answering that. I can’t guarantee that I won’t be sucked in again, but I can’t imagine I have anything new to say at this point.
“Back to string theory, does anyone know if it’s possible to stabilize all of the moduli without using fluxes, even for a special case? I think fluxes are ugly and give us the landscape, which I personally don’t like. ”
It is possible to stabilize the moduli without fluxes in M-theory compactified on singular manifolds with G_2 holonomy. See hep-th/0701034 for the details.
In this class of models the racetrack-type superpotential is purely non-perturbative and the hierarchy problem can be naturally solved via the dimensional transmutation. Moreover, surprisingly, in this construction the tuning of the CC results in a constraint which completely fixes the scale of gaugino condensation at ~10^14 GeV which in turn results in O(1-100)TeV scale superpartners.
LHC prophecies
One interesting part of this discussion in LHC prophecies and interpretations of various scenarios.
Peter Woit wrote (#260): “The all too depressing possibility is a 160 GeV (or whatever the number is that makes the theory consistent at very high energies) Higgs.”
In this case, Peter’s opinion that discovering the Higgs and no-more-and-no-less scenario is disappointing (even depressing) appears to be that of quite a few physicists. Looking at it well from the outside, I beg to disagree.
It is a possibility (to which I will give a substantial but small probability) that LHC will fail. (And it also seems likely that the time schedule will not be as expected; Setting the expected date for definite results to 2012/3 rather than 2009/2010 seems reasonable.) But once LHC will succeed to run it is a win/win/win situation.
If “only” the Higgs will be discovered this will be an amazing success for the scientific endeavor. (This is especially clear if you regard empirical verification of a scientific theory a major ingredient and not just a nuisance.)
Sure, like any major achievement it will raise the question, what is next. But as is the case after the Everest was reached, or the Moon, or the Poincare conjecture solved (in the affirmative as most people expected) the question of what is next is of secondary importance.
Of course, evidence for suppersymmetry will be another amazing success. Many physicists would not bet even money on this possibility but still regard it as a probable possibility. The stakes are so high that it certainly worth the wait.
In any case, there is a very good chance that in 5-6 years we will replace some tentative theoretical beliefs with a firm knowledge. This is what science is all about isn’t it? And if we will get a conformation for more speculative insights, and some unexpected data to keep are busy in the future this will be welcomed too.
Can beauty be debated?
The issue of beauty and physics is quite prominent in this discussion. Lee Smolin warns against adopting a physics theory based on aesthetic consideration and bring Kepler’s theory relating the five planets and five platonic solids as an example. Peter Woit makes (repeatedly, here e.g. on #145, and #252,) the claim that string theory is simply ugly, very ugly.
Well, beauty is a subjective matter. I remember my dear grand uncle Lena telling me:” Gina, aren’t we very lucky that people see things in a subjective way? If men were objective they would have all fallen in love with my own beloved wife (here name was incidentally also Gina,) who is clearly the most beautiful woman, and this could have caused all sort of complications.”
I, for example, regard string theory as very beautiful. Supersymmetry which grew up from string theory is an extremely beautiful notion. (In my view, suppersymmetry has a natural form of beauty while string theory has an exotic and peculiar beauty.)
But the really interesting question in my mind is how to debate beauty. Can beauty be argued and debated at all?
Here is a story about arguing beauty in court, which may be of use. It was a case were the defendant was accused of a terrible crime.
The attorney for the defendant said in his opening speech: “Look at the defendant. Looks how beautiful she is and look at her eyes of an angel. Do you really think she is capable of committing this ugly crime?”
At first, The prosecutor thought to ignore this remark altogether, but then the remark was repeated and similar sentiments were expressed by some witnesses. The prosecutor watched how this non-issue is becoming an issue and was worried that the beauty claims may convince some jury member.
The dilemma was not a simple one. Trying to argue that the defendant is not beautiful may convince a few jurors but will the strengthen the belief that indeed beautiful eyes is an obstruction for being a criminal. Trying to argue that there is no connection between the innocent angel look and the crime may give this whole business some credibility and may cause those jurors who believe in this connection to take for granted that the defendant is indeed beautiful
This is what the prosecutor said in his closing argument:
“Ladies and gentlemen of the jury. There are two types of beauty. There is the beauty that reveal a beautiful soul and there is the beauty that covers us a corrupted and distorted personality. It is very difficult to distinguish between theses two types of beauty, and often our initial hunches and intuitions turn out to be wrong.
We have carefully proved during this trial that the defendant committed the crime she is accused with, and therefore you must conclude that to the extent you find her beautiful this is a beauty of the bad kind, a beauty which covers a corrupt personality able to commit terrible crimes.”
(The moral is that if you want to argue against the beauty of string theory your best chance is, as Clifford Johnson often say in his tea-cup series, to come up with a real scientific argument against it. Of course, in such a case, the whole beauty issue becomes of secondary importance.)
BTW Woit’s blog (which recently contains a lot of cool stuff and relatively little dozes of boring string bashing,) has in the May 5 posting a link to an interesting discussion on beauty and physics theories.
Hi Gina,
yes, beauty is definitly subjective. But both, Lee as well as Peter, have made it more than clear what exactly they mean with that. Best
B.
Dear Bee,
You wrote regarding the beauty issue “Lee as well as Peter, have made it more than clear what exactly they mean with that”
If Peter’s approach is more than clear, is it clear to you, B, if Peter regards supersymmetry as beautiful or as ugly?
(Lee’s approach to beauty and physics is oveall quite reasonable.)
“(The moral is that if you want to argue against the beauty of string theory your best chance is, as Clifford Johnson often say in his tea-cup series, to come up with a real scientific argument against it. Of course, in such a case, the whole beauty issue becomes of secondary importance.)”
If you want to argue FOR the beauty of string theory, a real scientific argument for it would be useful, too. (Science as in empirical reality and not just something that you wish to be true.)
Hi Gina,
how about you ask Peter? You are the one who wrote he regards string theory as very ugly. I meant to say he has written a whole book that clarifies his opinion. That doesn’t mean you have to share it. In my subjective perception for example the length of this comment section is ugly. Best,
B.
Dear Bee and Anon,
Bee, Peter Woit’s discussion of beauty in physics (Chapter 13 in his book) is also quite reasonable, although I do not agree with his opinion that superstrings are not beautiful. In this thread, Peter refers to string theory as “ugly” ten times. (While criticism and skepticism are overall healthy and welcomed, the amount of repetitions here and elsewhere makes Peter skeptical style (also regarding other parts of the debate) a sort of “skeptical harassment,” which is, in my opinion, a rather problematic style of skepticism.)
I think that seriously thinking about the role of beauty in physics or science can be of interest. The evaluation of supersymmetry can be a good test case. If Peter indeed described a clear approach regarding beauty of physics theories, as you said, Bee, we should be able to predict Peter’s answer on this particular matter without asking him. (But, of course, I did ask him and he just did not reply, (which is perfectly OK).) Peter’s description of supersymmetry (Chapter 12 in his book) is very good and support my view that this is a very beautiful idea/theory.
Anon wrote: “If you want to argue FOR the beauty of string theory, a real scientific argument for it would be useful, too. (Science as in empirical reality and not just something that you wish to be true.)”
The issue is precisely how to discuss beauty. If ‘beautiful’ is just the same as ’empirically valid’, there is no point to talk about beauty at all. If ugly is a synonym for difficult or complex, again there is no point to discuss it as a separate concept.
Bee wrote: “In my subjective perception for example the length of this comment section is ugly.”
I am not sure, B. It may be true that we are well ‘over the hill’ here, but it is always nice to hope otherwise, no?