Model Building

For some interesting comments by Nima Arkani-Hamed about his model-building activities, followed by some of my own, take a look here.

Update: Jacques Distler has some comments on the Arkani-Hamed et. al. paper.

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10 Responses to Model Building

  1. Peter says:

    Thanks for spelling correction, just fixed it.

  2. Anonymous says:

    BTW, a spelling correction:  Nima Arkani-Hamed

  3. Quantoken says:

    Superstar said:
    “For those of us outside the network, who nonetheless are the ultimate source of it’s funding, what value does it provide? It’s looking more an more like it’s ultimate value is as entertainment. Or perhaps also as a way to impress the neighbors. Kind of like one great big living coffee table book for the nation.”

    Entertainment is good. It is a much bigger sector of human expendition than what we collectively spend on the whole front of science research. Making one typical movie costs more than sending one PathFinder to Mars. My own daytime work relates to the routine creation of real multiverses in virtual spaces of many dimentions, for the joyful entertainment of the playful population.

    Expenditure on Superstring research is nothing compare with the rest of pork barrel. If it expands the imagination of a few SciFi novel writers or allows making of a few SciFi movies, that’s more than the worth of the money already. The sad thing is so many of the smartest people jump into this seemingly hopeless quest, knowing full well they probably won’t have better luck in the next 25 years than the previous one, and that it may ultimately be proven to a wrong road which leads to no where. If that’s entertainment, isn’t it a bit too much cruelty?

    I agree with the notion that “let 1000 flowers bloom”. There should be an affirmative action in science research that when the main stream seem to be un-productive, alternative approaches and different tries should be encouraged, instead of being suppressed and censored.

    Remember, some of the greatest discoveries in science were made by a none-main-stream nobody, mere 26 years old, who could not even find a job teaching in a high school, and needed help to finally land a job as a third class clerk working in a small patent office. And whose ideas still look so wackered even today, that calling him “crackpot” would be a compliment to him.

    And this year is to be honored in his name.

    I still don’t know how that guy managed to get his stuff published at the time. Wasn’t there supposed to be a peer review process to maintain sanity in science publications:-)

    Quantoken

  4. Superstar says:

    The sociological network effect is certainly a big factor in the current dominance of string theory.

    For those of us outside the network, who nonetheless are the ultimate source of it’s funding, what value does it provide? It’s looking more an more like it’s ultimate value is as entertainment. Or perhaps also as a way to impress the neighbors. Kind of like one great big living coffee table book for the nation.

    Is it any wonder then that so many physicists are working on their own coffee table books these days, and the documentaries to go along with them?

  5. Anonymous says:

    “So just as network benefits accrue to users of inferior software [windows], inferior videotape systems [vhs], community benefits accrue to the dominant, if unsuccessful, scientific fad [conference invitations, x-archive postings, fellowships, book contracts, interviews, pbs specials].”

    This seems a bit cynical. The analogy between windows and vhs users with string theorists is improper. The software and videotape users (together with sufficient numbers of similarly acting people) provide the funding that in turn enables the community benefits. Clearly this is not the case with string theory research or other research that is funded publicly or by others who are not members of the string community.

    If community benefits are the primary coin of the realm, then a better analogy would be a community of parasites [the opportunists in the string community] feeding off the hosts [the funding agencies]. Not all parasites end up killing the host; let’s hope this one doesn’t [e.g., drying up of physics research funding due to inadequate benefits returned to the rest of the world].

  6. Anonymous says:

    Comment on Peter’s comment on Nima’s comment:

    Think of the string theory community as a social group with a “network effect” function of utility to it’s members. See for example:

    http://en.wikipedia.org/wiki/Network_effect

    In other words, regardless of utility to outsiders [rest of world] the community itself generates it’s own utility as a power or exponential of it’s own size.

    So just as network benefits accrue to users of inferior software [windows], inferior videotape systems [vhs], community benefits accrue to the dominant, if unsuccessful, scientific fad [conference invitations, x-archive postings, fellowships, book contracts, interviews, pbs specials].

    This is to be expected. The good news is that because of the power law of network utility a competing technology or theory with clear benefits can grow in size rapidly and overtake the inferior competitor. However the benefits have to be substantial to the defecting members, and outweigh the lost utility from detaching from the previous network.

    In the case of the competitors to string theory it seems that currently any apparent benefits do not offer enough utility for large numbers to defect.

  7. Anonymous says:

    Or

    Quantum Field Theory:Standard Model & related
    ::
    String Theory:specific predictive models built from a string vacuum.

  8. Tony Smith says:

    Commenting on the historical remarks of Nima Arkani-Hamed
    “… a big realization leading to the SM was that gauge theories should be important to the description of nature. … But it did not uniquely predict 3-2-1 gauge theory! … during a period in 77 or so when the experimental situation got very confusing. Critics of gauge theory model-building … said “Its unconstrained! You can build so many models!”. … When the dust settled, we had 3-2-1. …”
    Peter Woit said:
    “… in 1977 … SU(3)xSU(2)xU(1) with the SM particle content was … pretty well set in stone …”.

    Here is some chronology supporting Peter Woit’s comment:

    the electroweak force SU(2)xU(1) part of the SM was pretty much “set in stone”
    in 1971 when ‘t Hooft proved its renormalizability;

    the 1973 paper of Kobayashi and Maskawa, confirmed experimentally by the 1974 discovery of the charm quark and the 1976 discovery of the beauty quark, pretty much “set in stone” the color SU(3) 3-generation part of the SM; and

    in 1974 the 3-2-1 SM was so well accepted that Glashow and Georgi constructed SU(5) GUT based on the fact that SU(5) contains SU(3)xSU(2)xU(1) as a subgroup.

    Although some people in 1977 may have disagreed with the the 3-2-1 3-generation SM, their relevance to physics has been no more significant that the relevance of those who disagree with Einstein’s relativity.

    As to the situation today, it seems to me that string theory today has a financial / sociological dominance that is at least as strong as that of the 3-2-1 SM in 1977, but that string theory today has nowhere near the basis of detailed calculations and experimental results that the 3-2-1 SM had in 1977.

    As Peter Woit said:
    “… The real problem with particle theory these days is that the top-down approach has been nearly completely destroyed by the concentration on one idea of how to do this (string theory) and the refusal to acknowledge the colossal failure this has led to. …”.

    Another aspect of the problem is raised by Nima Arkani-Hamed’s statement “… there are specific hardware triggers at the LHC that are about to be finalized … we’re on touch with experimentalists and they will be modified …”.
    As Peter Woit said “… It’s certainly a good thing that model-builders are pursuing as wide a range models as possible in preparation for the LHC, especially if they’re talking to the people who are working on the LHC triggers. …”.
    However,
    if the only model-builders who have influence with LHC trigger designers are conventional string theorists, then the LHC may fail to observe events that could be very useful in evaluating models not based on conventional string theory.

    I repeat what I said in a comment to an earlier post:
    It is time to let 1000 flowers bloom and try lots of alternative approaches with equal hiring/funding and see which approach works best.

    For my part, since I have no influence on LHC trigger design, about all I can do is to be happy to defend my model in comparison with conventional string theory in any reasonable forum (for instance, I have submitted contributed talks about my model to the APS Tampa meeting 16-19 April 2005).

  9. Superstar says:

    In other words, Chris, you’re saying string theory is meta-physics.

  10. Chris W. says:

    Arkani-Hamed’s characterization of the work he and his colleagues are doing supports a picture* of string theory and landscape ideas as meta-theoretical frameworks — as theory generators. Given the constraints on the models he describes, this may well prove fruitful. However, any successes achieved by this path will be dubious empirical confirmations of string theory, since failures of these models couldn’t be taken as empirical refutations of string theory. That is why I’m inclined to regard the specific models as the real physical theories, and string theory itself as a web of related ideas (largely formal schemes) from which testable physical theories might be derived.

    Again, drawing an analogy with the case of general relativity, GR is the physical theory, whereas Riemannian geometry is only a meta-theoretical framework, notwithstanding the general notion that the structure of physical space (and later, spacetime) might be Riemannian and dynamic — an idea which was anticipated by Riemann and Clifford.

    (* previously discussed in the comments on this post)

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