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Math Science

String Theory Predicts Behavior of Superfluids 348

schrodingers_rabbit writes "Despite formidable odds, condensed matter physicists have made a breakthrough most thought impossible — finding a practical use for string theory. The initial breakthrough was made by physicist and cosmologist Juan Maldacena. His theory states that the known universe is only a 2D construct in anti-de-Sitter space, projected into 3 dimensions. This theory manages to model black holes and quantum theory congruently, a feat that has eluded scientists for decades; but it fails to correspond to the shape of space-time in the known universe. However, it does predict thermodynamic properties of black holes, including higher-dimensional viscosity — the equations for which elegantly and almost exactly calculate the behavior of quark-gluon plasma and other superfluids. According to Jan Zaanen at the University of Leiden, 'The theory is calculating precisely what we are seeing in experiments.' Unfortunately, the correspondence cannot prove or disprove string theory, although it is a positive step." Not an easy path to follow: one condensed matter theorist said, "It took two years and two 1000-page books of dense mathematics, but I learned string theory and got kind of enchanted by it. [When the string-theory related] thing began to... make predictions about high-temperature superconductors, my traditional mainstay, I was one of the few condensed matter physicists with the preparation to take it up."
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String Theory Predicts Behavior of Superfluids

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  • Yeah... (Score:5, Interesting)

    by paazin ( 719486 ) on Friday June 05, 2009 @08:51AM (#28221675)

    Unfortunately, the correspondence cannot prove or disprove string theory, although it is a positive step.

    That is to say, if you view that the proving of string theory to be true a positive step.

    • Re:Yeah... (Score:5, Insightful)

      by samriel ( 1456543 ) on Friday June 05, 2009 @08:53AM (#28221699)
      Enlighten me, why would proving a theory that is another step toward a GUT be a negative step?
      • Re:Yeah... (Score:5, Funny)

        by FredFredrickson ( 1177871 ) * on Friday June 05, 2009 @09:02AM (#28221837) Homepage Journal

        Enlighten me, why would proving a theory that is another step toward a GUT be a negative step?

        Well, you see, string theory is very complex, but really in the 2d universe we truly live in, it can be considered a negative step, but you won't understand it, because your used to only experiencing the 2 real dimensions and the incredible faux 3rd dimension, which is a construct of our brains to understand the space which we perceive. Anyway, the point is, if you really understand string theory, you see the negative step. But if you're standing behind the theory, it's a positive step. It's all relative.

        Re:Yeah... (Score:1) Mod Parent +1 WTF? POP-PHYSICS

      • Re:Yeah... (Score:5, Interesting)

        by jandoedel ( 1149947 ) on Friday June 05, 2009 @09:03AM (#28221845)
        if string theory is disproven, then we also know something more: the GUT is not string theory, ergo we need to direct our energy towards finding another theory. string theory is kinda unelegantly difficult, so a lot of people don't really want it to be true.
        • Re: (Score:3, Informative)

          by Abcd1234 ( 188840 )

          string theory is kinda unelegantly difficult, so a lot of people don't really want it to be true.

          Because quantum mechanics is so elegantly easy?

          I think we need to face facts, here: no GUT is gonna be simple. If it were, it probably would've been discovered already.

          • Re:Yeah... (Score:4, Insightful)

            by peragrin ( 659227 ) on Friday June 05, 2009 @12:51PM (#28225309)

            You can't simplify something until you understand it. Once we have a GUT it will probably reduce to PIRcubed of the universe expanding.

          • Re: (Score:3, Informative)

            by jandoedel ( 1149947 )
            Because quantum mechanics is so elegantly easy?

            well... actually it is relatively easy, and mathematically not extremely different from classcial physics. Basically you write a 'h' in some places where there used to be a '0', and that apparently has all this implications as wave/particle duality, uncertainty principle, observing = changing, etc...
            A bit hard to imagine, and sometimes counterintuitive, and the calculations can be quite some work (although QED and Feynman diagrams etc has made a lot of the
    • Re: (Score:3, Insightful)

      by elashish14 ( 1302231 )

      Unfortunately, the correspondence cannot prove or disprove string theory, although it is a positive step.

      That is to say, if you view that the proving of string theory to be true a positive step.

      Pardon me for the semantics, but no science/scientific theory can be "proven" - even the theory of gravity can't be proven. If I take a rock and drop it on my desk a million times, that doesn't prove that it'll fall there again on the 1e6+1th time. The same goes with the theory of evolution: nothing can prove evolution, but we just have a lot of evidence (fossils, experiments, etc.) that support it. A theory is supposed to make robust predictions, not sense. You can't understand science, you can only apply

      • Re:Yeah... (Score:5, Insightful)

        by gartogg ( 317481 ) <.DavidsFullName. .at. .google.email.> on Friday June 05, 2009 @10:11AM (#28222773) Homepage Journal

        Your point about semantics and the word proof is understood. Of course, you are conflating proof in a mathematical sense with scientific proof. Scientific theories are proven repeatedly, when testable predictions are confirmed. (This is the traditional use of the word in science) They can still be disproven, but scientific proof is very different than mathematical proof. Of course, proof in the common sense meaning of the word is a completely different idea, and yet a third thing. If you're going to make semantic points, make sure the words you use are the ones you want. "Proof" is a bad one to pick apart semantically, because there are a couple different meaning depending on context and meaning. (Yes, in the same context, the same word can mean 2 different things. That's language for you.)

        Of course, you then stop making sense. One CAN understand science. See many comments of Feynman about just that point.You may think you are a scientist, but you seem to think about science a hell of a lot like an engineer.

    • All you can say really is that the evidence fits the hypothesis, and therefore it hasn't been proven false.

      Think of it like sculpting. Eventually after you chip away all the junk you are left with a shape, or model which looks like the truth. You can't say it *is* the truth, but it sure looks a lot like it.
       

  • Science Fiction (Score:2, Insightful)

    by siloko ( 1133863 )
    Is it just me or does String Theory really sound like someone is making it up as they go along. It's like: "we haven't a clue whats going on but reality's so wierd we've decided to pull a theory out of our ass!"
    • Re:Science Fiction (Score:4, Insightful)

      by Anonymous Coward on Friday June 05, 2009 @08:56AM (#28221737)

      Umm, you've just described all scientific progress both past, present, and future...

    • Yeah, not like all that good science which is decided in advance and then rigidly adhered to!

      Wait a minute...

    • by mikael ( 484 )

      I think astrophysics is like that - I once went into a university bookstore to buy some recommended textbooks. On the top of the discount book table was a really impressive looking book with a some wireframe graphics on the front page. It was a summary of all the research carried out on the mathematical theory of black holes over 10 years (the size of two PC keyboards back to back). It was being sold at a discount because all the research was now out of date.

    • Exactly! Who the heck even -knows- what string theory really is? (beyond the pop-sci ``we model things as strings instead of point particles'').

      From what I've read, the equations are so broad that you can calculate and fit'em to pretty much anything (sorta like you can calculate anything with a general purpose computer...therefore, the computer is a physics theory---it calculates things so exactly!)

      The problem of string theory isn't its ability to predict. It's falsifiability. I've yet to see an experiment

      • Well that also says it can't be proven right either. Does that mean as they move they won't hit a point where they will have the abilitiy? No, so keep going if you want and see where it leads.
    • Re: (Score:3, Insightful)

      by Draek ( 916851 )

      To be fair, the same could be (and was) said of Quantum Physics as well. Reality *is* fucked up after all.

      Pity, Newton's equations were *so* much easier...

      • by Troed ( 102527 )

        It's becoming harder and harder for the ones controlling our simulation to keep up the impression of a live dynamic world. Having to stay one step ahead of our scientific progress in the simulated world, having to explain phenomena that were once thought out of our grasp yet documented (distant galaxies with the same rotation speed regardless of the distance from the core) and now needing explanations.

        We're close to seeing the illusion fail. I wonder if that makes the experiment invalid and if they'll just

    • No, it isn't just you. A lot of ignorant, know-it-all, non-physicist Slashdotters have made the same complaint.

    • That's all science ever is. Nobody knows what a wavefunction is supposed to be, but it's the core element of quantum mechanics and it's incredibly useful. Nobody really understand what entropy is either, or how you're supposed to understand things like enthalpy or Gibbs/Helmholtz free energy, but they're still essential for determining equilibrium systems/structures via thermodynamics and statistical mechanics. The value of a theory is based on how much it explains and whether it makes any useful, verifiabl

    • That's what I think about Dark Matter / Energy.

    • by lawpoop ( 604919 )
      They pulled a string theory out of their ass?

      In high school, I had a friend who had a small to medium 12-year-old yappy dog. He was blind, so he would bark at you even if he knew you, until he got close enough to smell you. Then he still might yap.

      One day he ate a baseball. A few days later, a string started coming out of his butt. They had to pull the string out, unless they wanted his to drag his butt string around all day. So they pulled, and when they did, he would yap. He was like some kind of life
    • by Gilmoure ( 18428 )

      Would be really cool if the Police got back together. That's my theory.

  • Wow (Score:5, Interesting)

    by pzs ( 857406 ) on Friday June 05, 2009 @08:55AM (#28221727)

    I'm always amazed that theoretical physicists can manipulate such immensely complex abstract objects in their heads and still be able to breathe and maintain bladder control. It really makes software engineering look like a piece of piss. Much respect.

    I would also say that having worked with academic medics, chemists, mathematicians, computer scientists and biologists, physicists are almost always the coolest, most down to earth and least douchey scientists out there.

    • Re:Wow (Score:4, Insightful)

      by Anonymous Coward on Friday June 05, 2009 @09:21AM (#28222045)

      It's because they look at how huge the universe is, how much energy is in it, how long it's all been around, how long it will most likely continue to be around, then truly comprehend how small, short-lived, and insignificant they are in the grand scheme of things.

      That kind of realization will humble anyone, no matter how smart they are.

      • Re:Wow (Score:5, Insightful)

        by 4D6963 ( 933028 ) on Friday June 05, 2009 @02:15PM (#28226375)

        "The grand scheme of things", yeah, I love how people compare themselves to the hole universe as if it somehow was the objective way to look at things.

        I don't compare myself to the whole universe, I compare myself to elemental particles. In that tiny scheme of things, I'm giant made of tiny molecules that make up cells that make up tubes and organs and shit, which millions of organisms and such living in me. I'm a world of its own.

        I'm being serious here, I don't get how people can go "oh look I'm so much smaller than the whole fucking universe, and so much younger too, that just blew my mind". I for one don't see how the size of the world you live in is relevant to what you are. That's just a misplaced point of view to look at yourself from. Also, I think it's just an exercise of mental masturbation in the dimensions abstractions department, i.e. it's hard to really picture to ourselves what large numbers really represent rather than just a bunch of zeroes, so the exercise of picturing how many times bigger than you the universe really is is humbling, but still completely irrelevant to your life. The universe could stop 50 kilometres up in the sky, it could be only 6000 years old, what would it change to you?

    • Re:Wow (Score:5, Insightful)

      by Fnkmaster ( 89084 ) * on Friday June 05, 2009 @09:23AM (#28222079)

      Very simple explanation - nothing in the universe builds humility like an education in physics. If you don't walk out of a physics degree feeling like you know less than you did when you started, like all you've done is build layer upon layer of model and gained only modest flashes of insight into reality after marathon sessions of math, then you've done something wrong.

      • by pzs ( 857406 )

        I don't know. Molecular biology is mind bogglingly complex but it doesn't seem to instill humility in those guys.

      • Re:Wow (Score:4, Interesting)

        by Jason Levine ( 196982 ) on Friday June 05, 2009 @11:23AM (#28223991) Homepage

        Well, I didn't get my physics degree. I stopped trying after Quantum Mechanics freshman year. I love relativity, but I felt like Quantum Mechanics was using one mathematical equation to prove another one which is used to prove a third. And so on. Eventually, you could plot the course of an electron around a hydrogen atom, but helium was too complex. Of course, a contributing factor might have been that my University didn't check the course requirements and realize that I didn't have the right level of Math to take Quantum Mechanics. I still love physics, but I still don't like Quantum Mechanics. (I passed the course with a C, but I think the only reason I didn't fail is that there were only 3 students in the course and the professor didn't want to have a 33% failure rate.)

      • Re:Wow (Score:5, Interesting)

        by catchblue22 ( 1004569 ) on Friday June 05, 2009 @12:24PM (#28224913) Homepage

        For me, I came out of my physics education with a realization that the world is far far far stranger than anything our everyday experience would lead us to believe. It has also left me with a strong sense that none of our knowledge is absolutely certain. That doesn't mean that I believe that our scientific theories are necessarily completely wrong, but rather that our current theories may very well be incomplete.

        String theory is definitely interesting. Gaining even a glimpse into it is far more humbling than learning quantum mechanics, and that is saying something! Where it will lead is completely unknown. For all we know, string theory may turn into a dead end (or into a massively complicated labyrinth with nothing but dead ends). Or it may turn into an immensely powerful predictive tool. Who can tell?

        There are alternatives to string theory that show promise in uniting quantum mechanics and gravity. I haven't fully digested this yet, but this paper summary [physorg.com] argues that space-time may have fractal elements that have the potential to predict both quantum mechanics and gravity.

        The bottom line is that the universe is immense, and immensely complicated, and we are small. In such a universe, certainty becomes an absurdity.

    • Re: (Score:2, Troll)

      Have you met old scientists? Smelly old men with irritable bowel and asthma.
    • Re: (Score:3, Insightful)

      by OldSoldier ( 168889 )

      Having a physics undergrad degree myself I always felt this humility was due to quantum mechanics. It is just so bizarre and so far removed from everyday common sense that physicists have to live every day with the realization that the universe *is* stranger than we can suppose. Pretty humbling.

      But also, it may be due to a much more rapid set of paradigm changing events in physics as compared to other sciences. Within the last 150 years physics has gone from renowned scientists saying that "we've almost dis

  • by Dystopian Rebel ( 714995 ) * on Friday June 05, 2009 @08:57AM (#28221753) Journal

    the known universe is only a 2D construct in anti-de-Sitter space, projected into 3 dimensions

    Well if THAT'S all it is, I see no reason to upgrade my video card.

    • by L4t3r4lu5 ( 1216702 ) on Friday June 05, 2009 @09:19AM (#28222021)
      Indeed. I hadn't heard of the term before, so I looked it up.

      In mathematics and physics, n-dimensional anti de Sitter space, sometimes written AdSn, is a maximally symmetric Lorentzian manifold with constant negative scalar curvature. It is the Lorentzian analog of n-dimensional hyperbolic space, just as Minkowski space and de Sitter space are the analogs of Euclidean and elliptical spaces respectively. It is best known for its role in the AdS/CFT correspondence.

      - http://en.wikipedia.org/wiki/Anti_de_Sitter_space [wikipedia.org]

      Well, glad that's cleared up!

      • by ColdWetDog ( 752185 ) on Friday June 05, 2009 @09:40AM (#28222301) Homepage
        Yeah, I looked at that Wikipedia article. Then I had to look up all of the other words.

        Then my head asplode.

        Thanks a lot!
      • by nyctopterus ( 717502 ) on Friday June 05, 2009 @09:46AM (#28222411) Homepage

        Gah! That's so common in technical topics on Wikipedia. The problem is that it is is written by undergrads and interested amateurs (I know, I'm one of them). Often they don't know the subject well enough to simplify it for a general audience, and are stuck putting it in the same language they learned it in. Simplifying a complex topic generally takes quite a degree of mastery, in order to know which simplifications are justifiable, and which would distort the concept too much.

        Also, I think sometimes they like to show off by writing things people can't understand.

        • by Timmmm ( 636430 ) on Friday June 05, 2009 @10:03AM (#28222667)

          "Also, I think sometimes they like to show off by writing things people can't understand."

          Definitely. E.g. the intro for "dot product" says "It is the standard inner product of the orthonormal Euclidean space." If you're trying to work out what a dot product *is* then that is a completely useless and confusing statement. Mathworld is usually much better than Wikipedia in this respect.

          • I remember reading that a very early dictionary (perhaps the first published in English) defined "network" as "a reticulation or decussation, with interstices between the intersections" or something like that. I think we've got the analogous situation here.

            Simpler things, in general, should not be described in terms of more advanced things. The article probably should say that the dot product is the standard inner product of the orthonormal Euclidean space, but it should be possible to understand the d

        • my two year old son can beat the shit out of a keyboard and write something that people cant understand. It is no reason to show off!

      • by OctaviusIII ( 969957 ) on Friday June 05, 2009 @11:17AM (#28223903) Homepage
        Suddenly, I have a greater respect for Star Trek technobabble, as well as the simple analogies that often follow.
  • by BadAnalogyGuy ( 945258 ) <BadAnalogyGuy@gmail.com> on Friday June 05, 2009 @08:57AM (#28221755)

    String theory works because the math works. There isn't anything special about the string theorists' model of humming cosmic strings that makes it work. All particle behavior is explainable using mathematics.

    What makes this interesting is that the model allowed for the construction of mathematical constructs that explain the behavior correctly. But it still doesn't say anything about the predictions that the model completely blows.

    What String Theory has, more than anything else, is a great set of marketeers behind it. Michio Kaku is a smart and articulate guy. It's not the steak, it's the sizzle.

    • by Fnkmaster ( 89084 ) * on Friday June 05, 2009 @09:27AM (#28222115)

      Any statistician will tell you that if you put enough free parameters in a model, you can calibrate it to the given data. Admittedly, string theory has some impressive parts to it, but it seems like it's just excess parameter fitting for a class of models that can all explain roughly the standard model.

      But if somebody does come up with a particular string-theoretic model with new, testable implications that get verified that would be impressive - it would certainly indicate that they are barking up the right tree rather than just working on a pleasant geometric abstraction that can be set up to reduce to the messy realities of our fundamental forces and particles.

      • Re: (Score:3, Informative)

        Parent post is insightful. If a model is flexible enough, it can fit any data.
        • If a model is flexible enough, it can fit any data.

          Wrong. If a model is flexible enough, you can probably make it fit a given set of data. But *all* data? No. If it could fit all data, it would be an *accurate model*... which is precisely what they're striving for.

        • Re: (Score:3, Funny)

          by Alzheimers ( 467217 )

          Strings ARE flexible! You can even tie them in knots.

    • by m.ducharme ( 1082683 ) on Friday June 05, 2009 @09:33AM (#28222193)

      So where's the competing theory, the one that explains things better, and is testable and whatnot? I hadn't heard that there really was one. My impression was that the one advantage the String theorists have is that they currently don't have any credible competition, though I confess that I haven't been keeping up with the debates.

      • Indeed. People seem to forget that it is by no means trivial to create a new theory that is even consistent with what we already know (put otherwise, that reduces to quantum field theory and relativity in the appropriate limits). And doing so is only the first step in getting a "better theory". After mere consistency it must make falsifiable predictions that differ from the old theories.

        At present there just are not that many approaches that have even been able to maintain consistency with established ph
      • by RobDude ( 1123541 ) on Friday June 05, 2009 @11:43AM (#28224305) Homepage

        That's basically the, 'If you can't completely and convincingly prove my wild theory wrong, then it must be correct' argument.

        "If God isn't real - then how do you explain ________"
        'Well, I can't explain ________ but I'm saying that there are problems and contradictions in your religious beliefs like,'
        "BWHAHAHA GOD EXISTS BECAUSE YOU CAN'T EXPLAIN WHAT STARTED THE BIG BANG".

        A lack of a better theory doesn't make a theory right.

      • Re: (Score:3, Interesting)

        by psnyder ( 1326089 )

        The competing theory is right here [ted.com]. AND it will be testable as soon as CERN is up and running.

        Whether it pans out or not, I exceptionally like this part of the introduction to his paper [arxiv.org], which I believe highlights the weakness of string theory.

        Hundreds of years of theoretical and experimental work have produced an extremely successful pair of mathematical theories describing our world. The standard model of particles and interactions described by quantum field theory is a paragon of predictive excellence. General relativity, a theory of gravity built from pure geometry, is exceedingly elegant and effective in its domain of applicability. Any attempt to describe nature at the foundational level must reproduce these successful theories, and the most sensible course towards unification is to extend them with as little new mathematical machinery as necessary.

        The further we drift from these experimentally verified foundations, the less likely our mathematics is to correspond with reality. In the absence of new experimental data, we should be very careful, accepting sophisticated mathematical constructions only when they provide a clear simplification.

        And we should pare and unite existing structures whenever possible.

  • But... (Score:5, Funny)

    by HaeMaker ( 221642 ) on Friday June 05, 2009 @08:58AM (#28221781) Homepage

    on page 642 of the second book, they divide by zero, so back to the drawing board.

  • Exciting (Score:4, Funny)

    by Rosco P. Coltrane ( 209368 ) on Friday June 05, 2009 @08:59AM (#28221793)

    one condensed matter theorist said, "It took two years and two 1000-page books of dense mathematics, but I learned string theory and got kind of enchanted by it.

    Boy, long winter evenings must just fly.

  • by disputationist ( 1324927 ) on Friday June 05, 2009 @09:11AM (#28221941)
    The Maldacena duality can't be used to 'make predictions' with a string theory, its just a correspondence between a string theory and a conformal field theory. It's useful because sometimes calculations which are hard in a CFT can be made in the corresponding string theory which is sometimes easier (or vice versa). It cannot be used to support the physical validity of some string theory.
  • I lol'd (Score:5, Funny)

    by Anonymous Coward on Friday June 05, 2009 @09:12AM (#28221945)
    The current tags (in order) for this story read to me:

    mygoddoyouknowwhatthismeans noidont stoptalkingintags

  • except the datum of there being _at_least_ 3 spatial dimensions.
    • by JustinOpinion ( 1246824 ) on Friday June 05, 2009 @09:36AM (#28222237)
      The holographic principle [wikipedia.org] doesn't mean that the universe has only 2 spatial dimensions, but rather that the universe can be modeled using one less degree of freedom than our view of spacetime would imply. Again, these kinds of theories are not suggesting that our space is two-dimensional, rather they are saying that the 3 dimensions we observe are emergent from a lower-dimensional description. All of the 'information' in a given region of space can be described as being encoded in the surface of said region.

      This remarkable, if bizarre, conclusion gains considerable support from the fact that black-hole entropy [wikipedia.org] (and entropy is a measure of information content) is related only to the surface area of the black hole. So this is a case where we know with some confidence that we can indeed reduce all the information about a 3D region of space (the black hole) to an expression that only relies on 2 dimensions (the surface of the black hole). The holographic principle appears in numerous theories that imply that this holds generally for any region of space, not just black holes.

      Now, whether you view this is 'just a mathematical trick' or 'a deep insight into the actual structure of the universe' is in some sense a matter of taste. (The same goes for all other physical theories: e.g. do electrons exist or are they just mathematically-useful constructs? How about photons? Gravity waves? Spacetime?) If you take the math seriously then this may mean that our universe is in some sense 'actually' 2-dimensional, with the three spatial dimensions we see being emergent instead of fundamental.

      But in no case is the theory saying that there are not 3 spatial dimensions. The predictions it makes are for particles moving through a 3+1 spacetime.
      • by Teese ( 89081 )
        The parent needs a higher score pronto. Hopefully a fundamental score of +5 insightful, and not an emergent one of +4 interesting +1funny

        I have no idea what I'm saying.

  • by Normal_Deviate ( 807129 ) on Friday June 05, 2009 @09:34AM (#28222203)
    The main criticism of string theory is that it is too flexible. It can be contorted to generate any prediction, so it predicts nothing. This problem is not unique to physics; I saw it in economics too. Add more parameters to your model and you can fit historical data better, but your predictions of the future get worse. TFA seems to be just a string of examples of contorting string theory to fit past experimental results.
    • Yes, that was my thought too. This work hasn't predicted anything at all, it's simply consistent with what was already known. To predict it has to tell us something we don't know that then turns out to be the case.
  • by jav1231 ( 539129 )
    But can it predict superfluity?

    :P
  • Give it time (Score:3, Insightful)

    by elashish14 ( 1302231 ) <.moc.liamg. .ta. .4clacforp.> on Friday June 05, 2009 @09:48AM (#28222453)

    Everybody gives string theory a hard time because it hasn't made any predictions, and because it can't be tested. Give it some damn time. It took ages before anyone could make useful predictions with quantum mechanics, and it was shunned for a while too (even by Einstein) and now it's an essential part of our scientific understanding. We shouldn't be so quick to cast out string theory either. Some time, eventually, maybe very far down the road (and if it turns out to be right), it too could be as useful as quantum mechanics has become. I wish scientists would just open their damn minds for once.

  • by hAckz0r ( 989977 ) on Friday June 05, 2009 @09:49AM (#28222465)
    Ok, I'll bite, which one? There are NUMEROUS 'String Theories' and they don't all mean the same thing. In fact I will be happy when the day comes that there is some kind of a 'Unified String Theory' so there is enough of it all in one place to be able to *disprove* something. Its kind of hard to prove that ten gallons of Jello won't fit in a bottle half its size if you can't get it all in one place at one time. You can't disprove something that you have not even sufficiently defined either.

    The major problem with String/F/D/Dn/S/Brane/M/Multiverse/Whatever's-next Theory is that every time someone finds a problem that doesn't fit with experiments/reality they just go and find an excuse and then modify the equations until it mathematically works out in that general direction. They don't start with the latest and greatest and modify that. They just pick their favourite Theory-of-the-day and add an extra dimension here, or there, twist it there, or subtract another infinite from both sides, because the formula is inconveniently looking incorrect at the moment. In other words, Just squish the Jello a little here and make it come out over there instead, until someone discovers 'the new mess' on the floor.

    If a theory has no basis in fact (i.e. no physical reality that can be described) then it is just Math. Math is not reality. You can model anything with Math, and it doesn't even have to exist.

    • by JustinOpinion ( 1246824 ) on Friday June 05, 2009 @10:13AM (#28222819)
      You are contradicting yourself. You say:

      The major problem with String/F/D/Dn/S/Brane/M/Multiverse/Whatever's-next Theory is that every time someone finds a problem that doesn't fit with experiments/reality they just go and find an excuse and then modify the equations

      but then complain:

      If a theory has no basis in fact (i.e. no physical reality that can be described) then it is just Math.

      If theorists are continually modifying their theories in order to fit with experiment/reality, and rejecting theories that don't fit with experiment/reality, then what's the problem? At that point it's not "just math", it's "math that correctly matches reality and makes predictions", which is the gold-standard in physics.

      Now, you may disagree with the particular mathematical formalisms the theorists are investigating, or the particular order in which they are checking them... but I don't understand how you can be upset at them for continually making changes in order to fit their theories with reality. That's what theorists are supposed to do: investigate a wide and wild variety of mathematical theories, and see which ones are able to make useful predictions consistent with experiment.

      They just pick their favourite Theory-of-the-day and add an extra dimension here, or there, twist it there, or subtract another infinite from both sides, because the formula is inconveniently looking incorrect at the moment.

      Again, this is an objection of procedure. If you can think of a faster way to uncover a mathematical theory consistent with all known experiments, then describe it. Until then, what's wrong with theorists checking a wide variety of theories (adding and subtracting terms/elements/dimensions as they go) until they find one consistent with observed reality?

      (And of course, in reality theorists are not performing the random-walk through theory-space you describe. They have very good reasons for checking the equations they do; their analysis is informed by many experimental results, previously-successful theories, and the structure of mathematics itself.)

      • What Justin Opinion said, only he said it better than I would've.
        In short, you can't just observe "strings" under a microscope, when you're discussing the actual "fabric" of reality, you can only speak in mathematical terms, because we're stuck inside this reality and can't remove ourselves from it to study it more objectively.

        But that's the way science works; you tweak your theory/math to better accommodate new observations (physical or mathematical); to either remove that which is "proven" fal
    • Yes, they modify existing theories to fit new facts. That's how science is done.
  • And everyone agrees that it STILL doesn't make sense.

    I am now totally convinced that Douglas Adams wrote this universe.
    • by jmoo ( 67040 )

      So true...if only scientist would develop bistromathics [wikipedia.org]
      "On a waiter's bill pad, numbers dance. Reality and unreality collide on such a fundamental level that each becomes the other and anything is possible."

  • by bingbong ( 115802 ) on Friday June 05, 2009 @10:28AM (#28223085)

    "Do you know string theory?"

    "No, I'm a frayed knot."

  • Spaghetti is tastier than string, and they could unify biology and physics with AdS/FSM spaces. How many dimensions has His Noodly Appendage?

"Look! There! Evil!.. pure and simple, total evil from the Eighth Dimension!" -- Buckaroo Banzai

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