Taking issue with String Theory

With the recent publication of Lee Smolin’s and Peter Woit’s books on the troubles of our theories of everything, every blogger in town seems to be talking about the crisis of modern fundamental physics (a.k.a. string theory and, so to speak, friends). Christine has just posted a list of recent posts on the subject. Like her, i’m reading Smolin’s book, courtesy of the publisher, and a review will eventually follow (once i find something to say about it that has not already been said!). In the meantime, i just wanted to add a few links to articles that i like on this pesky matter:

  • Jim’s Stab at String Theory is a very interesting discussion by Jim Weatherall on why it doesn’t really matters whether string theory is right. There you’ll find also a video interview with Peter Woit, by John Horgan (who is not specially happy with ST, either).
  • Among the free contents of the latest Physics Today issue, Burton Richter takes no prisoners when it comes to describe what’s wrong with all this super stuff.

I find Richter’s stabs, er, criticisms particularly compelling: his writing is clear and to the point, and his arguments are all but crisp and pungent. It’s curious that, by contrast, Smolin’s delicacy has actually augmented my curiosity on string theory (but i’m just halfway reading his book, so let’s better wait until i’m done).

On the other hand, i’m starting to be more and more in agreement with Weatherall’s arguments on the irrelevance of this whole business. At the very least, i’m trying to keep in mind that there’s arguably much more to fundamental physics than this debate. Maybe it’s time for some fresh air.

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4 Responses to “Taking issue with String Theory”

  1. Dick Thompson Says:

    I was reading “Jim’s take…” and am not convinced by his reasoning. Basically he says we shouldn’t worry that most funding for beyond-the-standard-model physics goes to string physics because the total number is so small as a fraction of the whole physics budget. But if only one cent out of every dollar goes to such physics then who gets that penny becomes all the more excruciating, not less! The same thing goes for the number of faculty at major universities. It has long been a gripe of GR physicists that they don’t get jobs due to old-string-boy (or old particle-boy) slants. And now the various kinds of non-string QG theorists are voicing the same complaint.

    The last part of Smolin’s new book is for me the most important, for that’s where he tries to locate what’s wrong with the practice of theoretical physics in the US through his own career experience. This is the part of the book I would like to see carefully responded to, rather than the easy target of his criticisms of string theory.

  2. Dick Ropiequet Says:

    I have not read Smolin’s new book. My comments result from reading Smolin’s web article about LQG, and studying “Not Even Wrong > Blog Archive >Dispute Chez Les Physiciens”

    What comes immediately to mind is Fermi’s warning to mathematicians that fitting equations to data doesn’t explain anything! Physical understanding advances only when we can picture what’s happening. He would say that the function of mathematical analysis is to select among and validate our various mechanistic constructs.

    In astrophysics we have pictures galore, so mathematical modeling of imagined mechanisms can be validated by computer reproductions of what is being observed. However, in particle and nuclear physics, although we have mountains of data, no scheme has been offered that permits us to visualize in 3-D, and in true scale, the photons, leptons, baryons, & nuclides that we infer from our detector displays. That is, until now!

    We lost our ability to visualize particles a hundred years ago when we abandoned the ether. The remedy; get it back! I show how this can be done on my website, where you will find how to:

    Make a comprehensive theory with just 2 fundamental particles.
    Visualize photon structures in 3D.
    Visualize lepton structures in 3D.
    Visualize dozens of meson structures in 3D: calc. m.e. to ±0.01%.
    Visualize dozens of baryon structures in 3D; calc. m.e. to ±0.01%.
    Visualize hundreds of nuclide structures in 3D; calc m.d. to ±0.02 Mev
    Visualize antimatter structures in 3D; calc. m.e. to ±0.01%.
    Visualize strong-force bonds mechanics in 3D;calc m.d. to ±0.02 Mev
    Visualize momentum structures in 3D.
    Visualize particle-creation processes in 3D.
    Explain how particles acquire charges.
    Explain wave-particle duality.
    Explain mechanics of particle-field interactions.

    Best wishes, Dick

  3. Shamal Jayakody Says:

    String theory is of interest to many physicists because it requires new mathematical and physical ideas to mesh together its very different mathematical formulations. One of the most inclusive of these is the 11-dimensional M-theory, and in the M-theory way of thinking, string theory requires space time to have eleven dimensions,[as opposed to the usual three space and one time. The original string theories from the 1980s describe special cases of M-theory where the eleventh dimension is a very small circle or a line, and if these formulations are considered as fundamental, then string theory requires ten dimensions. But the theory also describes universes like ours, with four observable space time dimensions, as well as universes with up to 10 flat space dimensions, and also cases where the position in some of the dimensions is not described by a real number, but by completely different type of mathematical quantity. So the notion of space-time dimension is not a fixed thing in string theory: it is best thought of as different in different circumstances.

  4. Themadscientists Says:

    I think that string-theory provides some novel ideas that extend beyond ordinary perturbation theories like the standard model. But how does it really correlate to physics?

    To imagine physics is an important task for science.. Without Dirac or Einsteins imaginations and the like, physics would be very limited indeed. But it is a mathematical construct that cannot be measured effectively, and this should be made much clearer when these theories are presented I think.

    However the moduar idea that M-theory presents (Or model-dependent realism as Hawking calls it) in incorporating existing physics is interesting for future theories and the notion that the laws of physics may be subject to evolution beyond the present point of understanding.

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