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The Future of Physics!
A few days ago I had the pleasure of briefly meeting Adam Becker, the author of What is Real?: The Unfinished Quest for the Meaning of Quantum Physics, and hearing him give a terrific introductory talk on the topic at Harvard's Science Center. Becker's isn't the first book to give maverick physicist David Bohm a fair shot, but it rather blew my mind (and thrilled me) that he first mentions Bohm in his Prologue. Bohm has gone from being omitted from popular books on physics to being the hook.

One of the things the talk did was explode the myth that Bohr won his debates with Einstein--a point I made in the first letter of mine that New Scientist ever published (the other two have been about neural correlates to consciousness):

"It seems grossly premature to declare any sort of victory for Neils Bohr in his great debate with Einstein over the meaning of quantum mechanics (26 February, p 36). Yes, the violation of Bell’s inequality in experiments by Aspect and others appears increasingly likely to rule out Einstein’s favored interpretation, local realism. But many physicists—going back to John S. Bell himself—would unhesitatingly put their money on the eventual acceptance of a non-local hidden variable theory such as David Bohm’s. And if that proves to be the case, then Einstein was correct about realism, correct about determinism (versus inherent randomness), but wrong about locality—while Bohr was wrong on all three counts."

Becker admitted that he's not a Bohmian. I think everyone should be. So here, from an answer on Quora, is what I think is a lockdown argument for something fundamenrally Bohmian being part of the eventual TOE.


Q: How long do you think it will be before a single interpretation of quantum mechanics beats the others (because of scientific evidence, not popular opinion)?

It won’t be scientific evidence that identifies the winner. It will be theoretical success.

I think that QM will be reconciled with relativity via the production of a deeper theory that produces both. The deeper theory will incorporate something close enough to Bohmian mechanics to declare it the winner. This follows necessarily from seven facts (in the original answer; an eighth has just been discovered.)

  1. Relativity cannot be the last word on the nature of space and time, because it cannot accommodate or explain the subjective experience of the passage of time, which is to say, consciousness. We are conscious of only what is happening in the present moment of time, yet in the Minkowski block universe there’s no such thing. There therefore must be a deeper theory of space and time from which relativistic theory emerges, and which can accommodate consciousness by featuring a real time.

  2. There’s a second, entirely independent argument that time must be real, and that we hence need a deeper theory. We’ve gotten used to the counter-intuitive idea that special relativity (SR) says that time is an illusion, but people miss that it also says that interactions (causal force) are illusory, too. Time has a fundamentally puzzling aspect—the conflict between theoretical reversibility and what we observe—that makes a counter-intuitive reframing seem quite plausible. This is not the case at all with interactions, which are the bedrock of physics. It’s extraordinarily counter-intuitive that when we’re struggling to separate two powerful magnets, all that “really exists” is the arrangement of matter in spacetime according to a set of mathematical rules, rather than an actual causal force.

  3. The seeming impossibility of reconciling general relativity and QM suggests that both QM and relativity emerge from a deeper theory. In this paradigm, the way you explain what happens very close to black holes or in the moments after the big bang is not via a theory of “quantum gravity”—the very concept of which is revealed to be a sort of category mistake—but by directly using the deeper theory, the one that is applicable in conditions before QM and relativity separate conceptually.

  4. Only Bohmian mechanics holds relativity (specifically, SR) to be other than fundamental; it calls for an absolute standard of simultaneity and frame of reference, neither of which we can ever detect (these would, however, be features of the deeper theory).

  5. Bohmian mechanics cannot be made compatible with SR, which some hold as its fatal flaw, but a careful analysis reveals that this is a feature, not a bug. Ordinary QM was made compatible with SR only by the enormous effort and work-around of renormalization. Such efforts have failed for QM and GR.

    Reframe this: the more complete version of QM, Bohm, is incompatible with both SR and GR, which is consistent. The version of QM that’s missing a key component (a mechanism for entanglement, which seems to violate SR ) can be jury-rigged for SR compatibility by the very dint of its incompleteness. But now the fact that SR can be made compatible with QM, while GR cannot, is inconsistent, and hence problematical.

  6. The ubiquitous quantum entanglement that uniquely characterizes Bohmian mechanics keeps on showing up elsewhere. It follows if you try to derive spacetime from information (which suggests that it follows if you try to derive it from anything more fundamental), and it also follows if you try to create a version of QM that avoids complex numbers (real-vector-space QM). Since complex numbers cannot refer to anything real and are just a mathematical shortcut, they need to be absent from the deeper theory.

  7. Bohmian mechanics removes QM’s fundamental randomness. A deeper theory has the potential to remove all of the weirdness of QM, by deriving the wave function as a genuine statistical mechanics and explaining how wave / particle duality arises.

  8. Update: On September 18, 2018, the world of physics was shaken by the publication in Nature of a gedanken experiment by Daniela Frauchiger and Renato Renner that shows that Quantum theory cannot consistently describe the use of itself. The paradox results when quantum measurements have been made, but observers ignorant of those measurements model the system containing them as still being in a superposition (as the QM formalism demands they do). I think there is a solid argument that only in Bohmian mechanics is there no paradox, because the philosophical import of Bohm is that it’s not legitimate to use QM to evaluate a system where a quantum measurement may have taken place. Superpositions and state reduction (“wave function collapse”) in Bohm are epistemic, not ontological; they reflect only our knowledge and not reality. Therefore, QM cannot be used recursively.

Bohm himself believed in a deeper reality beneath our observable one. One of his many ideas about the relationship of this “implicate order” to our “explicate order” was that the latter is a projection from the former. This idea predated the holographic theory (a finding from black hole thermodynamics which shows that the contents of any volume of spacetime can be projected from its surface) by many years. It seems to me like a surefire candidate for an element of the deeper theory.

I’d say five to ten years before we get something that looks workable.