söndag 2 september 2018

Weinberg Still (at 85) Unhappy with QM

Lubos reports on yet another talk by the famous physicist and Nobel Laureate Steven Weinberg, where Weinberg confesses that he is not happy with Quantum Mechanics QM:
  • In  a graduate course on QM, which eventually turned into a book, I found that I was unable to explain the foundations of QM in a way that I found (entirely) satisfactory.
Weinberg recalls that there are two interpretations of Schrödinger’s wave functions as solutions of Schrödinger’s multi-dimensional wave equation as the basic model of QM:
  • instrumentalist (wave functions predict outcomes of experiments).
  • realist (wave functions describe all possible worlds = multi-versa).
The instrumentalist interpretation says nothing about the world we live in, only something about certain experiments. 

In the realist or rather multi-realist interpretation, multi-d wave functions describe all possible worlds or multi-versa and thus the (quite special and particular) world we are living in gets little attention, if any.

With only these alternatives, it is not difficult to understand that Weinberg cannot make sense of QM. Weinberg also recalls that physicists agreeing that QM is correct, do not agree on what is correct.

Of course Lubos claims as usual that he can make sense to QM, or rather that there is no reason for him to do that, because this was done long ago. Not by Schrödinger or Einstein, but by Born who invented a probabilistic interpretation, which abhorred Schrödinger and Einstein.  

Weinberg has a Nobel Prize while Lubos runs a blogg. Weinberg says there is a problem with QM, which is denied by Lubos. What do you think? Is there a problem or not? Weinberg is at the end of his career and can afford to tell the truth.

In a travesty to a statement by Clark (Someone saying that something is impossible, is mostly wrong. Someone saying that something is possible, is mostly correct), one might say:
  • Someone strongly claiming that there is a serious problem, is mostly correct.
  • Someone shouting that there are no problems whatsoever, is mostly wrong.
If you think there is a problem with QM in its current form, you may be motivated to browse Real QM offering a new realist interpretation, where the objective is the world we are living in and not all possible worlds. Take a look!

One may say that the current deep crisis of theoretical physics witnessed by so many, is rooted in the status of QM as a theory which the expert cannot make sense of. So to get out of the crisis it is necessary to come up with a QM that makes sense. Right?

There are several new books sending the message that QM does not make sense therefore is not understood by physicists:
  • Beyond Weird by Philip Ball
  • What's Real by Adam Becker
  • Through Two Doors at Once by Anil Ananthaswamy.