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String Theory a Disaster for Physics? 737

Posted by timothy
from the sure-is-a-disaster-for-my-brain dept.
BlueCup writes "Mathematician Peter Woit of Columbia University describes string theory in his book Not Even Wrong,. He calls the theory 'a disaster for physics.' Which would have been a fringe opinion a few years ago, but now, after years of string theory books reaching the best sellers list, he has company."
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String Theory a Disaster for Physics?

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  • Man... (Score:5, Funny)

    by bcat24 (914105) on Friday June 23, 2006 @09:57PM (#15594071) Homepage Journal
    Some people really get tied in a knot about stuff like this.
    • Re:Man... (Score:5, Funny)

      by Tx (96709) on Friday June 23, 2006 @10:00PM (#15594082) Journal
      Yeah, it feels like these scientists are just stringing us along.
      • Re:Man... (Score:5, Funny)

        by Bruce Perens (3872) * <bruce@perens.com> on Friday June 23, 2006 @10:08PM (#15594134) Homepage Journal
        I get a hadron just thinking about it.
        • Re:Man... (Score:5, Funny)

          by Surt (22457) on Friday June 23, 2006 @10:13PM (#15594167) Homepage Journal
          We recently hired someone who worked at the LHC, and the company email that went out (small company announces all new hires) made that very obvious misspelling. Much hilarity ensued.
        • Re:Man... (Score:5, Funny)

          by cgenman (325138) on Friday June 23, 2006 @10:20PM (#15594209) Homepage
          What a charmingly strange thing to say.

        • Re:Man... (Score:5, Funny)

          by snuf23 (182335) on Friday June 23, 2006 @10:50PM (#15594355)
          Ack, it makes my brane hurt.
        • by 22RealMcCoy (864375) on Friday June 23, 2006 @10:56PM (#15594384)
          http://physicsmathforums.com/showthread.php?t=56 [physicsmathforums.com]

          Tied Up & Strung Out: Hollywood String Theory Movie!!! Looking For Extras!!!

          FOR IMMEDIATE RELEASE:

          ALL TIED UP & STRUNG ALONG, a movie about String Theorists and their expansive theories which extend human ignorance, pomposity, and frailty into higher dimensions, is set to start filming this fall. Jessica Alba, John Cleese, Eugene Levie, Jackie Chan, and David Duchovney of X-files fame have all signed on to the $700 million Hollywood project, which is still cheaper than String Theory itself, and will likely displace less physicists from the academy.

          "As contemporary physics is about money, hype, mythology, and chicks," Ed Witten explained from his offices at the Princeton Institute for Advanced Study, "The next logical step was Hollywood, although I thought Burt Reynolds should play me instead of Eugene Levy."

          Brian Greene, the famous String Theorist who will be played by David "the truth is out there" Duchovney, explained the plot: "String theory's muddled, contorted theories that lack postulates, laws, and experimentally-verified equations have Einstein spinning so fast in his grave that it creates a black hole. In order to save the world, we String Theorists have to stop reformulating String Theory faster than the speed of light. We are called upon to stop violating the conservation of energy by mining higher dimensions to publish more BS than can accounted for with the Big Bang alone, and I win the Nobel prize for showing that M-Theory is in fact the dark matter it has been searching for."

          Greene continues: "At first my character is reluctant to stop theorizing and start postulating, but when my love interest Jessica Alba is sucked into the black hole, I search my soul and find Paul Davies there, played by John Cleese. I ask him what he's doing in my soul, and he explains that the answer is contained in the mind of God, which only he is privy too, but for a small fee, some tax and tuition dollars, a couple grants here and there, and an all-expense-paid book tour with stops in Zurich and Honolulu, he can let me in on it. And he shows me God in all her greater glory, as he points out that we can make more money in Hollywood than writing coffee-table books that recycle Einstein, Bohr, Dirac, Feynman, and Wheeler. I am quickly converted, and I agree to turn my back on String Theory's hoax and save Jessica Alba."

          But it's not that easy, as standing in Greene's way is Michio "king of pop-theory-hipster-irony-the-theory-of-everything- or-anything-made-
          you-read-this" Kaku, played by Jackie Chan. Kaku beats the crap out of Greene for alomst blowing the "ironic" pretense his salary, benefits, and all-expense paid trips depend on. "WE MUST HOLD BACK THE YOUNG SCIENTISTS WITH OUR NON-THEORIES!! WE MUST FILL THE ACADEMY WITH THE POMO DARK MATTER THAT IS STRING THEORY TO KEEP OUR UNIVERSE FROM FLYING APART, OUR PYRAMID SCHEMES FROM TOPPLING, AND OUR PERPETUAL-MOTION NSF MONEY MACHINE FROM STOPPING!!" Kaku argues as he delivers a flying back-kick, "There can be ony ONE! I WILL be String Theory's GODFATHER as referenced on my web page!! I have better hair!"

          But Greene fights back as he signs his seventeenth book deal to make the hand-waving incoherence of String Theory accessible to the South Park generation, senior citizens, and starving chirldren around the world. "Kaku! Kaku! (pronounced Ka-Kaw! Ka-Kaw! like Owen Wilson did in Bottle Rocket)," Greene shouts. "It is theoretically impossible to build a coffee tables strong enough to support any more coffee-table physics books!!!"

          "Time travel is also theoretically impossible, but there's a helluva lot more money for us in flushing physics down a wormhole. Nobody knows what the #&#%&$ M stands for in M theory ya hand-waving, TV-hogging crank!!! Get it?? Ha Ha Ha! We're laughing at the public! We're the insider pomo hipsters! Get with the gangsta-wanksta-pranksta CRANKSTER
  • by Anonymous Coward on Friday June 23, 2006 @10:03PM (#15594102)
    asked a ninja [youtube.com].
  • String Theory (Score:5, Interesting)

    by Stalyn (662) on Friday June 23, 2006 @10:05PM (#15594120) Homepage Journal
    I think ST is a very interesting and peculiar theory. I'm not sure it's a disaster. Even if ST is proved wrong in some way the math that resulted from ST is still worthwhile. However I think Woit's point is metascientifical, in that string theorists get more funding than those who are trying to provide alternatives to ST. That ST has become somewhat of a marketing term. This is surely damaging but again science is not excluded from human frailty.
    • Re:String Theory (Score:4, Insightful)

      by Wonko the Sane (25252) * on Friday June 23, 2006 @10:15PM (#15594176) Journal
      In fact, "theory" is a misnomer, since unlike general relativity theory or quantum theory, string theory is not a concise set of solvable equations describing the behavior of the physical world. It's more of an idea or a framework.


      I think the article says it best. If we keep letting people use the term "theory" too loosely it just gives more ammunition to the intelligent design idi... proponents.

      In truth neither intelligent design or string "theory" is really a scientific theory as neither makes testable predictions yet. Maybe string theory will in the future but until then it is just an idea.
    • by mblase (200735) on Friday June 23, 2006 @10:39PM (#15594299)
      I think ST is a very interesting and peculiar theory. I'm not sure it's a disaster. Even if ST is proved wrong in some way the math that resulted from ST is still worthwhile.

      Think of Newtonian physics. We now know that Newton falls apart when viewed under the lens of Einsteinian relativity. But if you're dealing with relatively small masses, at relatively slow speeds, then Newton's physics works perfectly because relativity is too small a factor to affect the numbers. Likewise with quantum mechanics at the macroscopic level.

      Neither of those three "theories" is a complete and accurate view of how the universe works. They are each of them a model for certain situations, and which one you choose depends on which one is most appropriate.

      The thing about string "theory" is that it's more of a model than a theory. When physics gets down to this level, it's more mathematics than science. The theory/model that you use is never going to be perfect or complete, but as long as it fits the purposes you want it for, it's good.
      • by Stalyn (662) on Friday June 23, 2006 @11:35PM (#15594526) Homepage Journal
        ST is an attempt to unify QFT with GR. In that setting QFT and GR are a consequence of ST. However string theorists have discovered something called the landscape. In which not only is QFT and GR possible but so are 10^500 other types of universes and the theories that describe them.

        This is a huge problem. Of course there is the possibility that finding the ultimate theory of everything is impossible and this would be the physics dual to Godel's incompleteness result. Which I'm sure sure scares the shit out of many physicists.
        • by spune (715782) on Saturday June 24, 2006 @01:37AM (#15594939)
          The main problem I have with ST is that in its attempts to unify QFT with GR, the WGT becomes much too ambiguous with regard to WGO. Does our universe even qualify as proper SFU? And does ST demonstrate HTAW? Our universe, being ASLOM could be considered little more than a running simulation in the light of TBNT. The RFLN of alternate landscapes may not even BCWN; to assume there is a limit to their VPIN is shakey.
      • by pVoid (607584) on Friday June 23, 2006 @11:41PM (#15594548)
        The reason why ST is different from Newtonian, Maxwell's EM, relativistic or even quantum physics is not that it's more a mathematical model or some such thing...

        It's simply because each one of these theories were postulated starting from physical events, a model was conceived and using this model, we were able to predict phenomenons that we had yet not experienced.

        Case in hand: back in Newton's time, there were no air hockey tables. There wasn't anything that would make people think that an object would continue in a straight line at the same velocity if not interfered by any outside force. Try telling a medieval man that the mule and ox pulling his cart were only doing so to counter the force of friction on the wheel axle. He would laugh at you. Turns out, pretty much everything from going to the moon to airplanes could be explained if not predicted using newtonian theory.

        Maxwell, using nothing but simple equations not only 'found out' that light had a maximum speed, he measured the said speed. He's also the one who came up with e=mc^2, although he didn't quite know what that meant.

        Einsteins relativity. No need for an example.

        Quantum? As far fetched and sci-fi as quantum is, it explained how tainted glass can possibly be (something which made no sense in classical physics), it also predicted transistors (by the same tunelling principle).

        ST on the other hand, is a very very highly indirect 'theory' in which there has been practically no observation, and no verifiable predictions made. It's all underneath the cloak of the "too small to be verified". Which, when you really look at it, means it's on the same level as mysticism: as systematic as it might be inside of its confines, you have to first start by believing in it.

        All this being said, I'm not taking sides. I do hope that they eventually find something of relevance from it. I know a few people at least who've put their live's work into this.

    • Re:String Theory (Score:3, Insightful)

      by Raindance (680694)
      Yeah. And perhaps more important than the funding, many of the brightest physicists are going into String Theory- which, if it does turn out to be a dead-end, is a *lot* of waste, no matter the silver lining.

      ichin4's comment further down the page was rather insightful.
  • by manx801 (698055) on Friday June 23, 2006 @10:09PM (#15594145)
    There exists a universe in which major advances in Phyics would have been made if so many smart scientists were not distracted by String Theory.
  • String "theory" (Score:5, Insightful)

    by zephc (225327) on Friday June 23, 2006 @10:09PM (#15594147)
    I've never felt very comfortable with string theory. Not that it threatens some deep-held belief (I have few of those), but that it seems mostly like conjecture, trying to shoehorn increasingly complex theories to fit some phenomena that is probably explainable in a simpler manner which we just yet haven't found. Of course, physics often doesn't adhere to common sense.
    • by Black Parrot (19622)
      > it seems mostly like conjecture, trying to shoehorn increasingly complex theories to fit some phenomena that is probably explainable in a simpler manner which we just yet haven't found

      What if the universe is so complex that there's no explanation that's both simple and correct?
  • by aws4y (648874) on Friday June 23, 2006 @10:10PM (#15594149) Homepage Journal
    Let me point out that this has been well known in physics departments for years. The problem is string theory is nowhere near producing any prediction that can be tested, this means that it is not science, any more than mathematics is physics.
    • by Stalyn (662)
      There is this lurking idea that Number Theory is very important in Physics. Witten has been investigating this via the Langlands Program [northwestern.edu]. What if saying something is physically possible and mathematically possible is talking about the same realm of possibility. That is surely not how people think but if it was true would dramatically change our view of the world.
    • by node 3 (115640) on Saturday June 24, 2006 @12:31AM (#15594745)
      It very much is science, it's just not a proper theory. Perhaps "not yet" or "not ever" a proper theory, no one can say which is correct at the moment.

      Science, on the other hand, does not require one wait for the finished product. Working on string theory is working on science. It's just not complete, nor even all that useful currently. It's still in the early stages--a stage that is rarely so long and drawn out as it is in this case.

      For example, when devising special relativity, Einstein's theory was, at some point, still in the state string theory is in currently--that is, significantly conceptual, with a lot of math and refining yet to be done, and early on was entirely untestable making no real predictions. He was still engaged in science during that stage. That doesn't mean that special relativity was useful yet, nor do I mean to imply that string theory is correct or will bear fruit, just that even at this early stage it is legitimate to call it science.
  • Not so? (Score:5, Informative)

    by Kawahee (901497) on Friday June 23, 2006 @10:12PM (#15594164) Homepage Journal
    Michio Kaku in his book Hyperspace describes why we can't actually get very far with this theory, is because "nobody is smart enough to figure it out". Since it was an accidental discovery in the 80's, he describes it as "21st century math that accidently made its way into the 20th century". The problem is to do with phase shifts and perturbation theory:

    (Excerpted from Hyperspace: A scientific Odyssey through the 10th dimension)

        To understand this form of tunneling, think of an imaginary Charlie Chaplin film, in which Chaplin is trying to stretch a bed sheet around an oversize bed. The shit is the kind with elastic bands on the corners. But it is too small, so he has to strain to wrap the elastic bands around each corner of the matress, one at a time. He grins with satisfaction once he has stretched the bed sheet smoothly around all four corners of the bed. But the strain is too great; one elastic band pops off another corner. Every time he yanks an elastic band around one corner, another elastic pops off another corner.
        This process is called symmetry breaking. The smoothly strechted bed sheet possess a high degree of symmetry. You can rotate the bed 180 degrees along any axis, and the bed sheet remains the same. This highly symmetrical state is called the false vacuum. Although the false vacuum appears quite symmetrical, it is not stable. The sheet does not want to be in this stretched condition. There is too much tension. The energy is too high. Thus one elastic pops off, and the bed sheet curls up. The symmetry is broken, and the bed sheet has gone to a lower-energy state with less symmetry. By rotating the curled up bed sheet 180 degrees around an axis, we no longer return to the same sheet.
        Now replace the bed sheet with ten-dimensional space-time, the space-time of ultimate esymmetry. At the beginning of time, the universe was perfectly symmetrical. If anyone was around at that time, he could freely pass through any of the ten dimensions without a problem. At that time, gravity and the weak, the strong and the electromagnetic forces were all unified by the superstring. All matter and forces were part of the same string multiplet. However, this symmetry couldn't last. The ten-dimensional universe, although perfectly symmetrical, was unstable, just like the bed sheet, and in a false vacuum. Thus tunneling to a lower-energy state was inevitable. When tunneling finally occurred, a phase transition took place, and symmetry was lost.
        Because the universe begain to split up into a four- and a six-dimensional universe, the universe was no longer symmetrical. Six dimensions have curled up, in the same way that the bed sheet curls up when one elastic pops off first. For the ten-dimensional universe, however, there are apparently millions of ways in which to curl up. To calculate which state the ten-dimensional universe prefers, we need to solve the field theory of strings using the theory of phase transitions, the most difficult problem in quantum theory.
    • by dr. loser (238229) on Friday June 23, 2006 @11:14PM (#15594461)
      IAAP (I am a physicist). Out of all the bloviating, often obnoxious high energy physicists who feel compelled to write popular books with pretentious titles (Dreams of a Final Theory (Weinberg); The Quark and the Jaguar (Gell-Man); The God Particle (Lederman); The Cosmic Landscape (Suskind); A Brief History of Time (Hawking)), Kaku has absolutely contributed the least to the actual science. Lisa Randall is 10x the physicist of Kaku, if not moreso.
  • by postbigbang (761081) on Friday June 23, 2006 @10:19PM (#15594204)
    String theory is almost recursive.... a snake eating its tail.

    TFA is right in one thing-- it's lead to physicist bigotry.... an increasingly inbred idea that string theory rules and all else drools, but in dimension 9. So many things are unsolved.... and Hawking has helped but the mathematicians that used to rule physicists are finding themselves in a reverse role, where expostulations must be found to match equations which were pimped for expostulation.

    It's like curve-fitting, but with unprovable geometry, not Euclidian and not non-Euclidian.
  • by Tablizer (95088) on Friday June 23, 2006 @10:25PM (#15594236) Homepage Journal
    Maybe Intelligent Design can get some respect if other hard-to-test and long-shot hypotheses are allowed to be called "science". Just because backers tend to be religious does not by itself make it wrong. If a Darwin or SETI cult formed, would evolution or SETI's hypothesis grow less likely? Human bias does not change the truth values of the universe. If biased people want to hunt down evidence for long-shot hypotheses, so be it.
    • by MillionthMonkey (240664) on Friday June 23, 2006 @11:24PM (#15594488)
      Maybe Intelligent Design can get some respect if other hard-to-test and long-shot hypotheses are allowed to be called "science".

      Doubt it. Both string theory and Intelligent Design may be unfalsifiable, but then they are also unfalsifiable for different reasons. A major goal of string theory was to make the theory falsifiable, by looking for low energy phenomena that could be predicted by it. The string theorists failed, because their theory takes place in what turns out to be an unobservable realm with no observable predictions, but at least they were trying. Intelligent Design's unfalsifiablity was built into it by design.

      String theory could still surprise you. They might make unexpected progress and come up with some string-theory derived explanation for some low energy phenomenon, like the mass of the proton. But Intelligent design will never successfully predict a thing since by nature it is not a predictive theory.
    • by UserGoogol (623581) on Friday June 23, 2006 @11:56PM (#15594604)
      Intelligent design is a bit of a lower quality than String Theory. String theory is in principle testable, it's just that the tests are somewhat out of our ability at the moment. How on Earth do you test ID? An intelligent designer can do whatever the hell he wants. In order for Intelligent Design to be testable, it needs to postulate a particular designer with particular goals and particular mechanisms for effecting the genetic code of organism. More problematically, the traditional creator of "God" would not do, because a big part of the traditional definition of God is that his will is ineffable.

      I'll admit that Intelligent design is not an inherently terrible idea. It's not impossible that we might find "fingerprints" of intelligent design, and that this might lead to trying to investigate the idea more closely. Furthermore, investigating how human "intelligent design" has effected the evolution of other species is certainly a worthy subject for research, and something which people do research. But as it is currently formulated, Intelligent Design is not testable enough to be anywhere near the realm of "science." At least String Theory tries.
  • by ichin4 (878990) on Friday June 23, 2006 @10:30PM (#15594263)

    I am an (ex-) particle theorist. I worked on phenomenology, which is how particle physicists describe people try to work with actual data.

    I don't think the rise of string theory has been the cause of the dearth of breakthroughs in particle physics in the last 30 years, but rather the effect. For all that time, nothing unexpected has come out of accelerator experiments -- just more confirmations of the predictions of the standard model developed in the 1970s, and more accurate measurements of its parameters. In an environment like that, it's no surprise that theoreticans turn to highly speculative and mathematically challenging models to keep their work interesting.

    There are still some related fields generating new and interesting data for good young theorists to cut their teeth on -- cosmology, for example.

  • by ilyag (572316) on Friday June 23, 2006 @10:45PM (#15594333)
    I think the whole problem is that string theory is misclassified. As far as I understand, the whole reason for its existance is that people have noticed several beautyful equations for strings in 12-dimensional space. On the other hand, we are as far now from seeing a measurable connection between these equations and the world around us as we were 20 years ago.

    This is not physics because physics ultimately deals with the real world around us, with things we can measure or at least hope to measure. However, since this is a beautyful theory, this is math.

    IMHO, any beautyful math will someday find its application and even if it doesn't, it should be done solely for its beauty. In any case, if string theorists would start calling themselves mathematicians, all the problems with string theory would disappear. Just don't expect it to have any obvious applications.
  • Some Comments (Score:3, Insightful)

    by shma (863063) on Friday June 23, 2006 @10:49PM (#15594348)

    First off, I should point out to those that aren't familiar with the world of physics that Lee Smolin is one of the principal advocates, at least in the public discourse, of Loop Quantum Gravity, a competitor to String Theory. That is certainly not to say he's bashing string theory for his own benefit, though. His arguements are all quite sound.

    Secondly, in my own experience, speaking to physics professors about string theory, we're starting to see some saturation in the number of students willing to work on topics in string theory for their PhDs, and as jobs become more scarce for those who enter into the field (after all if they don't advance with predictions, there's less and less to do), we'll see more people entering into other areas, ro examining other theories.

    And finally, I should point out that the last line, That string theory abandoned testable predictions may be its ultimate betrayal of science , is extremely insulting. I'm sure there's nothing string theorists would like more than to come up with a testable hypothesis that could be tested immediately, but the fact is that it's a difficult subject. Just because we can't test it now is no reason to start crying "pseudo-science".
    • by dr. loser (238229) on Friday June 23, 2006 @11:29PM (#15594505)
      A real concern is that the "landscape" (the fact the string theory is really a collection of theories that could have something like 10^500 (yes, that's a googol to the fifth power) possible vacua as solutions) renders string theory nearly unfalsifiable. It's not that they can't predict anything. Indeed, they've predicted everything. If the LHC at CERN started up tomorrow and found a Higgs boson with a mass of 220 GeV, and some kind of light supersymmetric partner at 260 GeV, they could claim that's consistent with string theory. Heck, if the Tevatron folks at Fermilab found a fourth family of leptons next week, the string community could claim to understand that, too. I would love to see just one example of something that could credibly be found at the LHC that string theory can't explain. Just one.
      • http://arxiv.org/PS_cache/hep-ph/pdf/9709/9709318. pdf [arxiv.org]

        Chapter 6 counters your arguments in a way that I think is quite clear (for a string theory paper, at least).

        And while I won't try and claim there's some particle that we can discover at the LHC that string theory can't explain, by not finding light supersymmetric partners of existing particles, the LHC has the possibility to disprove string theory.
      • by Bill Quayle (712339) <quayle@NospAm.wisconsin.cern.ch> on Saturday June 24, 2006 @06:44AM (#15595517)
        My officemate pointed me to a paper the other day where the authors (Distler, Grinstein, and Rothstein) were saying it might be possible to falsify strig theory with WW and ZZ scattering measurements (although they don't talk specifically about these measurements at LHC). The paper is on lanl.gov and the reference is hep-ph/0604255. I'm not a theorist, but it looks to me like the basic argument is that if there is no light higgs, and certain bounds on the WW and ZZ cross-sections are not satisfied, then the S-matrix is either non-analytic, non-unitary, or not Lorentz invariant at some scale. And the authors say that since string theory is constructed to satisfy these assumptions at all scales, it would be invalidated if one of them were not correct.

        But I do find it rather amusing that you'd have to give up something like Lorentz invariance or unitarity to disprove string theory.
  • Carver Mead (Score:3, Interesting)

    by Ian Bicking (980) <ianb@colo r s t u d y .com> on Friday June 23, 2006 @10:49PM (#15594349) Homepage
    It's not really related, but I found this interview [blogspot.com] with Carver Mead very interesting. Related in that it's also about progress (or non-progress) of scientific theory.
  • Trust (Score:5, Funny)

    by Oligonicella (659917) on Friday June 23, 2006 @10:53PM (#15594369)
    Never trust anyone who makes up dimensions to make the math work.
  • a counter argument (Score:4, Informative)

    by chenzhen (532755) on Friday June 23, 2006 @11:18PM (#15594474) Homepage
    I am a string theorist. I would write my own rebuttal to Peter Woit, who is well known in the community for being very vocal about his opinions, but it has already been well [cosmicvariance.com] done [cosmicvariance.com] (these are blog posts by Sean Carroll at Chicago/Caltech).

    I'm all for public education on all topics of physics, including string theory, but this is an unfortunate case of a little bit of knowledge being dangerous for armchair physicists. In order to properly understand string theory requires understanding conformal field theory, supersymmetry and supergravity, Riemann surfaces, Kaluza-Klein theory, and so on, just to name a few of the introductory ideas. I don't think it's too unreasonable to assume that most of Peter Woit's audience has not studied any of these. But without studying string theory, I don't think it's possible to judge whether or not the things string theorists find compelling are in fact sufficiently exciting to warrant the attention it receives from them. For my part, I think they are.
    • by Mark Maughan (763986) on Saturday June 24, 2006 @05:42AM (#15595426)
      I am a theoretical physicist. I am educated in Supersymmetry, Riemannian geometry, and the original Kaluza-Klein theory. I am educated in field theory in curved space time, but not Supergravity, nor do I care to be.

      I have only one thing to say about all of this. Everytime I sit in a talk on strings or branes all I can think is one thing.

      Extra dimensions are the epicycles of Modern Physics

      That's all I have to say. If you understand this, it is profound.
  • statistics (Score:5, Interesting)

    by kakapo (88299) on Friday June 23, 2006 @11:39PM (#15594544)
    I am a cosmologist, albeit one who works "close" to string theory (I am not a string theorist, but many of my collaborators are), and I am familiar with Woit's arguments (and have met the gentleman himself several times).

    However, my impression -- and I speak as someone who works inside a particle theory group, and who has served on faculty-level particle physics search committees -- is that string theory is far from having a "lock" on theoretical particle physics today. In the article, Woit is quoted as follows: "By his count, of 22 recently tenured professors in particle theory at the six top U.S. departments, 20 are string theorists." Looking at the Particle Physics Rumor Mill (http://physics.wm.edu/~calvin/) which assembles the short lists for faculty jobs in particle theory many of (and perhaps most) the people getting offers are not "hard core" string theorists. Many of them will have written papers with some string content, but have wider interests in cosmology, particle phenomenology, and/or physics "beyond the standard model".

    This statistic differs from Woit's, in that it is not just counting "top" physics departments, and looks at Assistant Prof hires, and not tenured faculty (although *outside* the top six, most Assistant Profs can expect to be promoted to tenue). However, I suspect that the "twenty out of twenty two" statistic is either over a very carefully chosen interval, or reflect a very broad definition of who counts as a "string theorist".

    My feeling is that string theorists have a *hard* time getting jobs. In general, many places outside the top ten (ande most of the jobs are outside the top ten) do not have string theorists on their faculty, and string theorists have a hard time differentiating themselves from other people in their field, which makes it hard for them to get hired -- especially as they are competing against other, very smart people.

    The real issue here is that particle physicists have received no "surprises" in many years -- perhaps the only genuinely unexpected recent data point being the non-zero value of the cosmological constant. And this did not create a new problem, since the challenge for the theoretical community was always to explain why the CC was around 10^120 times smaller than its "natural" value, which is not much easier than explaining why it is actually slightly different from zero. In this enviroment, we have no good way to "prune" theoretical ideas, and the hope of many is that the LHC (Large Hadron Collider) will yield results that cannot be explained within the context of the so-called "standard model" of particle physics. In this sense *any* theoretical framework that had been worked on since the mid 1970s would risk falling into the same trap as string theory, since there is no data we can't explain with existing models -- if it was incompatible with the standard model it would have been dead on arrival, but any model which yields the standard model in some limit is not falsifiable with current data.

    On the other hand, string theory does provide a rich mathematical structure with some very surprising results. The so-called "AdS/CFT" correspondence sets up a completely unexpected relationship between gravity and a particular class of field theories, and some calculations in QCD (the theory of the "strong" nuclear interaction) can be "organized" and performed using string theoretic ideas. This does not "test" string theory, but it does show that there are deep and unexpected consequences to what is ultimately a very simple idea and, in the absence of data, this motivates theoriests to keep working in this area.
    • Re:statistics (Score:5, Insightful)

      by The_Wilschon (782534) on Saturday June 24, 2006 @12:16AM (#15594696) Homepage
      The real issue here is that particle physicists have received no "surprises" in many years -- perhaps the only genuinely unexpected recent data point being the non-zero value of the cosmological constant.

      Excuse me? You should try keeping up with experiment if you're going to make broad statements like this. Minos, up here at fermilab, recently discovered that neutrinos do in fact have mass. This was suspected a year or few ago, which was why Minos was built, but is nonetheless quite surprising. It is surprising because it is really the first definitive measurement which is nearly unquestionably outside the standard model. (I don't need to tell you this, I suppose, but others will read this too: The standard model assumes explicitly that neutrinos have no mass at all.)

      Anyway, the problem that most experimentalists, such as myself, see with String Theory is that in some ways it is a step backwards from the standard model. It is purported to be "parameterless", which contrasts with the plethora of unconstrained parameters that the standard model contains. However, this is really only a bit of sleight of hand. Instead of numerical parameters, which are (relatively) easy to measure, and continuous, we now have the topology of space, which is discrete (no smooth change from one topology to the next) and quite difficult to measure, and embodies immensely more variation than the parameters of the standard model.
  • Missing the Point (Score:5, Interesting)

    by wildsurf (535389) on Saturday June 24, 2006 @12:01AM (#15594627) Homepage
    The statement that string theory makes no testable predictions does not necessarily limit its usefulness. As I understand it, the mathematics behind quantum theory and relativity are irreconcilable, in that they lead to infinities and singularities when extended into each others' domain. The brilliance of string theory is that it provides a general framework that encompasses both quantum theory and relativity, and thus it may be a superset of the "true" framework of the universe, if not the most concise description. The idea that string theory is "bad science" only because our universe may be one of 10^500 possible configurations (and string theory can't predict which one it is) is like saying that statistics is bad science because it can't predict the exact run of cards I'll have at my next poker game. The development a framework within which our observed universe is possible at all (which cannot be said of relativity or quantum theory) is a tremendous achievement in itself.

    Think of it this way. Many theorists predict that our universe may be one of many (e.g., in a much larger "multiverse"), and these universes are not all expected to be identical. Therefore, the variations between them represent quantities that are not exactly "predictable" by any theory, and the best we can hope for is a meta-theory that describes all possible universes, and says that ours is one of them. The earth is not the center of the universe; the prediction of string theory may simply be that our universe is not the center of the universe, so to speak.
  • The problem is... (Score:5, Interesting)

    by Pedrito (94783) on Saturday June 24, 2006 @01:28AM (#15594909) Homepage
    Newtonian gravity came about because Newton had an idea and then used math to express it. Relativity came about because Einstein had an idea and then used math to express it. Quantum physics came about in a similar fashion. An idea (or ideas) and then math to express it (them).

    The problem with string theory is that some equations came along that fit the data in an intriguing way and so physicists pursued and continue to pursue the math. The problem is, it's not based on some sort of idea that someone had. The idea is the thing that's missing. Math is great at expressing ideas, but it's not particularly good at creating them.

    It could be that at some point, someone will come up with an underlying conceptual idea that the math can then be used to express, but until that happens, I don't think string theory is really going to become a practical theory.
  • by spetey (164477) on Saturday June 24, 2006 @01:57AM (#15594996) Homepage
    "Untestable! Unfalsifiable!" This is a common refrain from string theory critics, and even from many string theory fans - and it really bugs me. I'm a philosopher of science, and I say: forget falsifiability!

    Well, don't completely forget falsifiability - but don't let it be the whole story. Falsifiability was already outdated philosophy of science 50 years ago. Its main problem is what's sometimes called the "Quine-Duhem Thesis" - roughly speaking, any treasured theory can be made to fit any evidence, as long as you're willing to adjust enough auxiliary hypotheses. Here's an ordinary example: when your high school science lab experiments didn't fit predictions, your results didn't get published in Science for falsifying the theory at hand. Instead, quite reasonably, you drew the conclusion that something wasn't quite right with the instruments, etc., and you kept the original theory. The tricky question is to figure out when it's reasonable to excuse recalcitrant data, and when you're unreasonably trying to rescue a theory that's just wrong. Intelligent design advocates can lay out all sorts of falsification criteria, and then make similar excuses should unhappy data come their way. So does that make ID a science? (If on the other hand you insist that only actual falsification makes something a science, then only theories we no longer believe can count as scientific!)

    It's too easy in all sciences - not just string theory - to make theories "supported" by the data. Given this problem, the name of the science game is to find the simplest explanation that fits the data. It's very hard to say exactly what counts as a simpler theory, but some theories are clearly less simple. Compare the hypothesis that "the butler did it" to the hypothesis that "unknown sneaky aliens planted all that evidence to make it look like the butler did it." Both hypotheses fit the evidence equally well, but the latter is clearly less simple, and we normally never even consider it for a moment.

    String theory explains all the data, from quantum physics to relativity, with a simplicity that's hard to beat. (Its elegance is so good, we're apparently willing to posit 11 dimensions for it!) That's what makes it a legitimate scientific theory. Of course it would be great to have more relevant data, to see if string theory can accommodate them simply too. But just because we can't get such data (now, or maybe ever) doesn't spoil the current scientific status of the theory.
    • If on the other hand you insist that only actual falsification makes something a science, then only theories we no longer believe can count as scientific!

      That's actually a reasonable and sound position. It's more or less impossible to prove something correct in science - we've discovered many times that if a theory looks right on one level, when you go deeper it's just a good approximation. So you can never really be sure whether you've found the right answer, or just something close to it. And from our experience of science the odds are in favour of the 'good approximation' side.

      On the other hand, when you've proven something wrong, you're pretty damned sure that it's wrong. It's then a scientific fact. You can't do that for something that appears right - it's more like a scientific guess.

      It's important to keep this in mind - remember that something you believe to be correct is almost certainly not correct in every particlar. And follow up on those "Hmm, that's odd" moments, because those are how progress is made.
  • by m874t232 (973431) on Saturday June 24, 2006 @07:01AM (#15595551)
    Many physicists stopped being scientists some time in the 20th century; they stopped following the scientific method, their experimental methods became sloppy, and so became their reasoning. They started valuing theoretical elegance more than testable hypotheses, and they became more enamored with formulas than data.

    I think Einstein may have been responsible for that development: while relativity was a great insight and made useful, testable predictions, it falsely instilled the belief in physicists that Einstein's way of doing physics was the way they should all follow. The problem with that is that most physicists aren't as smart as Einstein, and even if they were, there is only a small number of self-styled visionary scientists any field can comfortably accommodate before becoming unscientfic.
  • by Physics Nobody (688399) on Saturday June 24, 2006 @03:38PM (#15597362)
    First off, I should note that I am a nuclear/particle physicist so I actually know something about this stuff.

    Yeah, the vast majority of string theory is probably crap. But what people don't seem to realize is that 99% of what all theorists say is crap. That 1% that actually manages to get something right gets all the fame and tends to be the only ones the general public hears about, but the sad truth is that most theorists take the shotgun approach: They try to come up with as many different theories as possible in the hope that one of them might actually turn out to be right.

    The article seems to imply that the existence of string theorists is preventing advancement in particle physics. That's BS. The reason why there haven't been any new dramatic discoveries in particle physicists in the past few years is because there haven't been any new experiments! Science is experimental in nature. Progress is made with new experiments. The theorists can speculate all they want but no consensus will be reached until somebody tests it. Unfortunately experiments in particle physics have become so massive and expensive that progress has slowed significantly.

    Actually, there have been many discoveries in less traditional aspects of particle physics...neutrino mass for instance. So I'm not even entirely sure what the article is complaining about. Yeah, traditional accelerator experiments haven't done much since the discovery of the top quark at Fermilab, but again it's because there haven't been any new experiments since then. Other than RHIC, which focuses on a very different kind of physics (and RHIC has also been producing many interesting new results).

    When the LHC finally comes online expect a flurry of new discoveries. Until then the theorists can speculate all they want. If they weren't wasting their time on string theory they would be wasting their time on something else.

I'd rather just believe that it's done by little elves running around.

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