How to resolve the so-called “paradoxes” of quantum mechanics?

Wednesday, December 5th, 2018

Neovictorian reviews The Brave and the Bold, Volume 3 of The Hidden Truth, which I also enjoyed, but this quick aside is what most caught my eye:

Meanwhile, I understand that Dr. Schantz is working on a popular physics book with some ideas about how to resolve the so-called “paradoxes” of quantum mechanics.

Yes, please.

Yes, please, indeed.


  1. Bob Sykes says:

    It might be helpful to read Lubos Motl.

  2. William Newman says:

    Quantum mechanics also has a lot of serious weirdness wired into it that is not particularly paradoxical (and not at all controversial, with consequences that are pretty close to direct experimental observation, not hidden deep behind arcane statistical analysis of difficult experiments) just weird. Besides the famous example of things acting both like particles and waves, consider antimatter, and the Pauli exclusion principle.

    AFAIK the “paradoxes” people like to fuss about generally aren’t paradoxes, they are mostly people refusing to believe what the equations say, mostly unreasonably (i.e., in regimes where the experiments can be done and lo, turn out like the equations say) and occasionally sorta justifiably (in regimes where the equations simply break down into nonsense, as in the interaction between QM and cosmically cataclysmically superstrong gravitational fields, or in regimes where maybe the fundamnental equations don’t break down but we still have great difficulty solving the equations very well, as in QCD).

    The closest thing to an exception that I can think of is the paradoxes related to the “Einstein/Podolsky/Rosen paradox”, in which the equations are conceptually hard to reconcile with Einstein’s plausible intuition that information doesn’t travel faster than the speed of light. That’s not quite a paradox — Einstein’s intuitions don’t have to be right, they merely had a respectably good batting average — but at least worth poking around in very carefully. And so naturally, it has been done… The resolution is fairly typical quantum weirdness in that it is clearly mindblowing (more or less: the elves running the show conspire faster than light behind the scenes, while you in the audience still cannot take advantage of this behavior to send messages to other audience members faster than light) but unambiguously what the equations say and lo, what the (difficult) experiments turn out to say as well.

    It is not unheard of for physics to be surprising or unintuitive once it gets away from the experiments that children can do with sticks and puddles and marbles and rubber bands. Admittedly uantum mechanics carries this to a new extreme, but even electromagnetism shows this pretty well, and even thermodynamics shows it a little bit. E.g., even though in hindsight the first and second laws of thermodynamics show up in everyday experience, they were not AFAIK foreshadowed by anyone’s informal common sense. And the way that magnetic fields curve around electrical currents, while changing magnetic fields induce electrical currents, also seems to take people by surprise. And the way that Maxwell’s equations accommodate magnetic monopoles on the same footing as electrically charged particles, but the universe just seems to have none of them anyway, seems at least as annoyingly unintuitive as the EPR paradox. But despite the traditional name for the EPR paradox, neither EPR nor missing monopoles are truly a paradox, and AFAICS there isn’t anything to resolve, it’s merely the universe flaunting its prerogative to behave in its own peculiar way regardless of whether that’s what you might reasonably anticipate.

    The blowup where fullblown general relativity (superstrong gravitation) meets QM is a real problem, but it’s not a paradox, or at least it’s not an idiomatic use of the word paradox. It’s halfway closely analogous to the old “ultraviolet catastrophe” in the pre-quantum statistical mechanical analysis of black body radiation. The closely analogous half is that then as now, the equations blow up so badly in that regime that they really can’t be right. The entirely unanalogous part is that experiments on the relevant regime for the ultraviolet catastrophe (both variants of black body emission, and other heat-and-EM-radiation experiments like the famous photoelectric effect) were straightforward to do on a tabletop with a reasonable budget, while the QM-vs-GR problems generally arise in “thought” experiments involving utterly insanely extreme conditions like the Big Bang (or, e.g., first procure two black holes heading toward a very near collision…) that are completely out of reach of current experimental tech.

  3. Neovictorian says:

    Great comment, William Newman, but I wrote “so-called ‘paradoxes.’”

  4. Alrenous says:

    Quantum mechanics isn’t that surprising.

    What’s very surprising is that gyroscopes know which way to precess. How do they know the right-hand rule? They don’t have hands, let alone brains.

    Similarly, a wire loop with a current being driven by a Lenz’s law type interaction both has a voltage and has no voltage. It must have a voltage, as current is being driven. W = V*A. It can’t have a voltage, because the situation is rotationally symmetric, so the potential must be the same everywhere.

  5. Bob Sykes says:

    I apologize for two comments, but I had to respond to this:

    “Einstein’s plausible intuition that information doesn’t travel faster than the speed of light”

    Faster than light travel or communications must be forbidden to preserve causality. FTL means no causality. And that is the issue for physicists.

    Finally, it has been noted that Einstein’s theory of General Relativity is the last flowering of classical physics, and that Einstein is the last great classical physicist. While General Relativity has been confirmed numerous times, it has to be pointed out that classical physics failed its tests, particularly in the case of the ultraviolet catastrophe. Quantum mechanics was developed in response to its failures.

    Schantz, whose book I am currently reading (good Heinlein) is evidently a multi-worlds Bohmist (of pilot wave fame).

  6. Kirk says:

    Causality strikes me as a human conceit, a demand to the universe that it make sense, an imposition of order where there is none.

    The general idea of causality is that it is a mechanism whereby you are prevented from creating paradox by way of changing something when you travel in time, something you are bound to do when you set out to subvert the limitations of light’s speed. Presumably, to do that, you will have to step outside the framework of our universe, and then return. Having done so, what makes anyone think that the return is going to be at the same point in time? Outside the framework, time is just another variable, and there is no reason you would automatically come back into the framework at the same point in time you left it.

    Which puts causality into a bit of a quandary; how does it handle the new information your return represents? My guess is that we are going to find that it doesn’t care–Go back in time, kill your grandfather, whatever; causality police are not going to chase you down and erase you. Too much work; instead, you are now severed from consequence because of that trip through whatever lies outside of spacetime, and represent a new reality where your murder of grandpa is immaterial to your actual existence. Grandpa’s dead, and everything he contributed to making you is irrelevant, because for the purposes of causality, your existence in this frame wasn’t brought about by your birth, but by your entrance into it from outside the current spacetime framework that causality works within.

    Breaking the lightspeed rules will have consequences way past what we are thinking, and I suspect that our classic hard-and-fast view on causality will be one of them. And, of course, the scale of the thing is going to make it really hard for classic views on causality to work–Say that getting to Proxima requires traveling back in time a few thousand years, along with spanning the distance. How is “changing the past” going to affect anything here, at that remove?

  7. I appreciate the interest in my fictional and scientific work. In real-life, I’m not a “Many-Worlds” proponent. It’s merely a great fictional justification for an alternate history science fiction tale. There are, however, overlooked “hidden truths” in electromagnetics that could have been uncovered a century ago. You’ll find a summary of my electromagnetic ideas in this blog post: Dirac’s Big Mistake. Alternatively, here’s a video lecture I presented at a conference a few years back.

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