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It's important to avoid conflating string theorists with all theoretical physicists. Plenty of people in particle physics either don't believe in string theory

• Ma8ee 7y ago
  String theory has completely dominated the field of theoretical high energy physics for decades. There have been some notable contrarians, e.g., Smolin and Woit with their books. But those haven't changed the fact that it has been very hard to get a faculty position in theoretical hep for decades without being a string theorist. It is only the last few years that has changed. In other words, it's not a biased view that string theory has completely dominated the field for more than 30 years. Btw, the reason we aren't reading Feynman's take is that he died in 1988, not that he's too busy doing physics. He was very successful in doing both high quality physics and expanding his popular reach.
  • knzhou 7y ago
    That's just not true. Look at the statistics for hiring faculty in theoretical high energy physics [1]. String theory was never more than half, and usually much less than that. (It is true, though, that for a while they had a near monopoly on pop physics. But that's totally different from physics.) [1] http://www.particle.physics.ucdavis.edu/rumor/doku.php?id=statistics http://www.particle.physics.ucdavis.edu/rumor/doku.php?id=st...
    • jessriedel 7y ago
      His statement can be true if you restrict it to "quantum gravity" jobs (of which string theory is one of many approaches, abeit the overwhelmingly most popular one). The other jobs you're talking about just don't try to answer the questions that string theory purports to addresses.
      • whatshisface 7y ago
        Despite its drawbacks string theory may actually be our best theory of quantum gravity, perhaps even enough to justify its hiring ratio relative to other quantum gravity theories. Maybe string theory has been treated in a balanced way all along.
        • Ma8ee 7y ago
          Maybe, or maybe not. My personal opinion is that even thirty years ago it seemed stupid to bet almost all resources on a theory that was too complex for anyone to even produce any testable predictions. And I think it is even more stupid now, when the main result of the theory seems to be that it's not possible to use it for any prediction (10^500 possible universes, it's not possible to say which one).
          • whatshisface 7y ago
            Unless you mean "almost all PBS physics documentary budget dollars," I don't think almost all resources were bet on it.
• improbable22 7y ago
  "would have trouble making predictions. Physicists have made this criticism since the beginning." You can go one step further. If you regard string theory as an attempt to answer questions about quantum gravity, then this criticism applies to the whole question, not just to any particular school of thought about answering it. This was known since approximately the time when physicists first had access to Planck's constant, Newton's constant, and a spare envelope to write on. But, as you say, this is far from all that people who get called string theorists work on. A great pile of mathematical tools have been developed, to the point where deliberate ignorance of all of them would be a very strange position. Not for all fields of theory, obviously, but for quite a few.
• mannykannot 7y ago
  > [Horgan] puts all his energy into expanding his popular reach. I would not say 'all', but this bet fits the claim. If he had lost, his position as a prescient naysayer would be gone anyway, while a win could be used to boost it, even though, as it happens, no decisive case against string theory (or for an alternative) has emerged in the interim. In a sense, this bet is a columnist's hedge against there being no news. For any counterparty, however, a win would have been completely overshadowed by the science itself. A person might be happy to accept the bet as a form of harmless entertainment, but for Horgan, it was more than that.
• bufferoverflow 7y ago
  It should really be called String Hypothesis. Theories in science are generally for something that's near 100% proven.
  • westoncb 7y ago
    The difference between hypotheses and theories isn't about whether one is more likely true, they are different kinds of structures with different roles. A hypothesis is ideally 'atomic': it's making a single assertion that should be falsifiable by experiment. A theory provides a specific way of modeling the elements of some field of study, and how those elements interact with one another. It should be structured in such a way that it can describe the components of any experiment that might be set up to confirm/reject a hypothesis in this field. And once an experiment is described in the terms of some theory, the theory should provide a systematic way of calculating what the result of the experiment should be. That's where the connection between hypotheses and theory comes in: actually conducting experiments assigns either Acceptance or Rejection to a set of hypothesis; ideally, the theory assigns the same Accept/Reject values to the same hypotheses in its predictions (this is probably never 100% the case in practice though—esp. not in an active field of study). The structure of String Theory is much closer to theory than hypothesis. (It may have limitations in how much it models physical 'experiments,' but it's at least much more of a 'system description' than an atomic assertion.)
  • thanatropism 7y ago
    That's a trope made up on the spot to defend Darwinism from "it's just a theory/teach the controversy". Whether in science or police work, etc. a theory is a holistic framework, while a hypothesis is truth-valued. We should also complicate this idea that something can be 100% proven, but baby steps.
  • hansen 7y ago
    Physicists and philosophers of science give those terms different meanings. E.g. what a philosopher of science would call a theory is called model by physicists. What physicists call a theory is more a broad framework in which more concrete models can be build. From the view of a philosopher of science string theory isn’t even a hypothesis as a hypothesis needs to be testable
• SomeOldThrow 7y ago
  How is holography any more concrete than string theory? It is just as untestable.
  • knzhou 7y ago
    You use it as a tool to compute what happens in real things, such as quark-gluon plasma or certain condensed matter systems.
    • evanb 7y ago
      You should be careful to not overstate it's rigorous application to QGP or condensed matter systems though. For example, for QGP, holography can paint a nice picture, but we don't know a holographic dual for Nc=3 QCD.
    • SomeOldThrow 7y ago
      We must not be discussing the same thing. EDIT: yup, I am not knowledgable enough to be in this conversation.
• nxpnsv 7y ago
  All string theorists are theoretical physicists, noz all theoretical physicists are string theorists. Many string theorists contribute in other fields.
• mikorym 7y ago
  The advantage of being a mathematician is that the unifying theories for QM and GR just that, mathematical techniques to unify QM and GR. Unfortunatly, if you are a physicist, I assume your grants at some point will have the words "predictions" or "experiments" in them. But for someone focused on mathematics, string theory, quantum loop gravity (if that is what it's called) and all the others become tools and objects of study on their own that have a unique perspective to offer in their own right. Whether you study one or the other then becomes a personality inspired preference. Just because I don't study number theory, doesn't by default scorn the field (or perhaps I just can't do number theory).
  • improbable22 7y ago
    In quite a few countries, string theorists (and usually GR people too) are far more likely to be in mathematics departments than in physics. Pretty much for the reasons you describe -- GR was seen in the 60s as an exotic mathematical playground, not quite real physics.
    • mikorym 7y ago
      This is also true of QM (not just because of QM computational sciences). My MSc thesis has application to quantum mechanics. I wrote a short summary of the generalisation that I made here [1], which generalises what the Nijmegen group calls quotient comprehension chains to sets. The authors of the latter QC-chains did not seem much interested when I emailed them. In any case, ideally the framework should touch on geometry eventually as well, but I am not aware of concrete ways to do it. Toposes are considered geometric, but I don't know whether geometric in the sense of GR. The eventual or at least, hopeful, end point is something like [2] where your mathematical framework should ideally in the language of categorical or functorial duality express physical dualities. I don't know how to get to GR, as I say, and should read maybe this [3] but there are many ways to get to QM. One example is through entropy: the generalised abstract set subobjects are partitions and partitions encode entropy through "distinctions", i.e, elements in separate equivalence classes of the partition. The category of sets itself is a model for QM theories via it's inspiration for (symmetric) monoidal categories so perhaps one would want to express in the self-dual language that as well. It's one thing to point to multiple uses of category theory in physics, but it is another to keep track of it in your personal, internal intuition strategy. [1] https://arxiv.org/abs/1808.01350 https://arxiv.org/abs/1808.01350 [2] https://en.wikipedia.org/wiki/AdS/CFT_correspondence https://en.wikipedia.org/wiki/AdS/CFT_correspondence [3] https://ncatlab.org/nlab/show/duality+in+string+theory https://ncatlab.org/nlab/show/duality+in+string+theory
• JohnJamesRambo 7y ago
  Well I’m not reading Feynman’s take because he is dead right now.
  • gimboland 7y ago
    I like the "right now" there. Like, fingers crossed, that could change...
    • varjag 7y ago
      It's not impossible, just isn't very probable.
    • FiatLuxDave 7y ago
      Obligatory xkcd: https://xkcd.com/397/ https://xkcd.com/397/