Thursday, July 27, 2017

Physics took a wrong turn with unification

I have agreed with Lubos Motl the last few times I have mentioned him, which is worrisome, but I do disagree with his post on wrong turns:
what was the first wrong turn in theoretical physics [?] ...

There would be "more moderate" groups that would identify the grand unification as the first wrong turn, or supersymmetric field theories as the first wrong turn, or bosonic string theory, or superstring theory, or non-perturbative string theory, or M-theory, or the flux vacua, or something else.

I've met members of every single one of these groups. ...

Some critics of the evolutionary biology say that zebras and horses may have a common ancestor but zebras and llamas can't. Does it make any sense? ...

The case of the critics of physics is completely analogous. If grand unification were the first wrong turn, how do you justify that the group SU(3)×SU(2)×U(1) is "allowed" to be studied in physics, while SO(10) is already blasphemous or "unscientific" (their word for "blasphemous")? It doesn't make the slightest sense. They're two groups and both of them admit models that are consistent with everything we know. SO(10) is really simpler and prettier ...
No, SO(10) is not really simpler and prettier, and such thinking was indeed a wrong turn in 1973 that lead theoretical physicists into a 40-year dead-end.

You justify the group SU(3)×SU(2)×U(1) because all those group parameters were grounded in experimental observations. SU(3) is the 3-color-quark theory of strong interactions, SU(2) is the weak (beta decay), and U(1) is electromagnetism. SO(10) adds many new particles and phenomena that have never been observed and have no experimental basis.

Supposed SO(10) unifies the forces, but it doesn't. It doesn't reduce the number of coupling constants or experimentally-determined parameters. It doesn't make the theory or analysis any easier.

I have a theory that this wrong turn, and also a bunch of other subsequent ones, were rooted in some misconcepted about big physics successes of the past, notably relativity and quantum mechanics.

Those theories were grounded in experiment, but there is a widespread belief that Einstein should get all the credit for relativity because he ignored the experiments and carried out the supposedly essential step of elevating principles to postulates. I wrote a book on How Einstein Ruined Physics, explaining the damage from this warped view of Einstein.

So physicists came to believe that all the glory in physics goes to those who do such sterile theorizing. Hence grand unified theories that do not actually unify or explain anything.


  1. Roger,
    I would make the argument that grand unified theories actually do explain something. They explain what happens when too much funding for science comes primarily from one centralized source, the government.

  2. Yes! Einstein, in his younger years, tended to root all of his thoughts on physics in experiment and physical contemplations. In his later years, his blind faith in math took over.

    Unfortunately, the string theorists adapted all the methods by which Einstein failed while rejecting those by which he succeeded.

    And too, Einstein could have done even better in his younger years by referencing the experiments of Michelson-Morely as well the work of Lorentz, Fitzgerald, and Poincaire who *did* reference the experiments including those which Maxwell's Equations were based on.

    Physics made a VASTLY wrong turn in the seventies, or perhaps even earlier, and they built a massive empire of handwavy failure about it.

  3. You are absolutely correct. Modern physicists and others have learned the wrong lessons from Einstein.

  4. Yes! In many ways Woit, Bee (Sabine Hossenfelder), Lubos, and Smolin all agree that the future of physics will be determined by using "symmetries" and other abstract math to contemplate things such as loops, strings, and quantum gravity--none of which have ever been observed.

    Woit concludes, "The history of the last 43 years is that this idea isn’t a successful one: as this talk shows, it leads to an empty theory that explains nothing. Can one find different new ideas about symmetry that are more promising?"

    After 43 years of failed symmetry-seeking, Woit suggests we need more symmetry.

    Feynman was far wiser. He knew that physics always advanced in different manners, but that it was most often rooted in experiment and observation.

  5. Yes. I like that math of symmetry as much as anyone else. But it is just foolish to believe that new physics is going to be discovered by abstract theorizing about what symmetries are the most beautiful.