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Weirdest physics proved beyond doubt?

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Einstein’s hidden variables tests two ways, closing both loopholes. From the Economist:

To save physics from the spooky, Einstein invoked what he called hidden variables (though others might describe them as fiddle factors) that would convey information without breaking the universal speed limit.

By now, most physicists reckon the hidden-variable idea is flawed. But no test had closed both loopholes simultaneously—until this week, that is.

Ronald Hanson of the University of Delft and his colleagues, writing in Nature, describe an experiment that starts with two electrons in laboratories separated by more than a kilometre. Each emits a photon that travels down a fibre to a third lab, where the two photons are entangled. That, in turn, entangles the electrons that generated the photons. The consequence is easily measured particles (the electrons) separated by a distance that precludes any shifty hidden-variable signalling.

Over 18 days, the team measured how correlated the electron measurements were. Perhaps expectedly, yet also oddly, they were far more so than chance would allow—proving quantum mechanics is as spooky as Einstein had feared. More.

Unless, the Economist suggests, every single event in the universe was predicted in advance from outside. Of course, that’s unfalsifiable.

Quantum mechanics is spooky, but contrary to some hopes, it doesn;t add up to something from nothing.

One wishes people would research the history of such ideas before buying in. See “The universe as Ponzi scheme.

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15 Replies to “Weirdest physics proved beyond doubt?

  1. 1

    To a large extent the quantum spookiness is the same as the logic of choosing in common discourse, making it look less weird.

    One of the main differences is, while in qm the entangled particles are in the present, in common discourse alternatives are said to be in the future.

    Which is right common discourse or qm? Could it not be found that the entangled pair, or the space parameter of the entangled pair, exists at time t+1?

  2. 2
    nightlight says:

    I happen to be theoretical physicist who had this problem (quantum paradoxes, mainly non-locality) for my master’s theses. Since mid-1970s these claims would come along periodically every few years, and only when the next group of ‘quantum magicians’ comes along it is suddenly revealed to the gullible reporters and public — ‘oops, the previous experiment had a very subtle yet fatal flaw and only this new one is actually the real thing’.

    Those who who have seen the routine many times will just roll their eyes. The latest quantum magicians get to bask in their temporary glory for few years, while quietly but quickly snatching the loads of funding, until the next team of magicians decides it’s their turn now.

    In this case the inevitable fatal flaw is fairly easy to spot. Since the Nature paper is paywalled, use the free arXiv copy here.

    You basically have setup with 3 experimental locations which are far apart (see Fig 1, page 2 and its description):

    A —— C —— B

    The spins to be measured in the final step (and demonstrate the alleged ‘quantum non-locality’) are at the A and B locales. The location C contains the ‘event-ready’ detectors (photo-detectors). In each test the light photons interact first with spins at A and B, then they are sent from A and B to C where the two photons are measured in order for ‘event-ready’ computer logic at C to decide and signal YES/NO to A and B indicating whether spins at A and B should be tested. Then, on YES, the spins at A and B are measured in one of two ways, and magically they show apparent non-local correlations. On NO, that try is not counted and new try is started.

    It is clear though that the measuring procedure itself, with its common ‘event-ready’ detection & decision at common location C, is explicitly non-local, hence the claim is bogus.

    Consider analogy of ‘telepathic’ magician twins at A and B claiming they can ‘randomly’ pick the cards from the far away decks, one twin at A the other at B, and make them match at greater rate than regular chance would allow. But then, their magic procedure consists of each twin picking the card, then each sending their messenger to C, and then the two messengers meet at C to decide whether this test instance is to be counted or discarded.

    Anyone with few brain cells would tell them, ‘is this a joke? you call that telepathy? get out of here’. Of course, when this same kind of magic procedure is obfuscated in the heavy technical jargon, reporters and public, as well as some investors (lured by the promise of magic ‘quantum computing’ which rests on the existence of the above effect) will get duped.

  3. 3
    Mapou says:

    The word “nonlocality” is a ruse. It masks the real meaning behind it which is nonspatiality. In other words, space (volume or distance) is a perceptual illusion albeit a very powerful one. But the undeniable truth is that space and distance are abstract concepts. Position is the only property needed to explain the location of a particle, something that any video game programmer can tell you. Position is one of the intrinsic properties of a particle, not of some external space. Distance is derived from positions. Thus it is superfluous. Besides, it leads to an infinite regress. If space exists, where is it?

    This is something that German mathematician and philosopher Gottfried Leibniz already understood centuries ago. He wrote:

    …space is nothing else but an order of the existence of things, observed as existing together; and therefore the fiction of a material universe, moving forward in an empty space cannot be admitted.

  4. 4
    Mapou says:

    The reason that the true meaning of nonlocality is hidden is that, if it came out, it would immediately falsify the Einsteinian relativity doctrine that insists that only relative positions exists in reality. It is a false doctrine because it leads to a self-referential reality.

  5. 5
    Mapou says:

    nightlight:

    Then, on YES, the spins at A and B are measured in one of two ways, and magically they show apparent non-local correlations. On NO, that try is not counted and new try is started.

    I find this hard to believe. Do you have a specific quote in the paper where this is mentioned or do I have to read the entire paper to verify your assertion?

  6. 6
    nightlight says:

    @5 — If you wish to skip through quickly, just search for strings “YES” and “event-ready” or even better, “ready”. That should tie for you the relevant textual references and confirm my summary.

  7. 7
    EvilSnack says:

    Do the photons always entangle? If not, are the state of the electrons measured anyway?

    If the answers to both questions are “no”, then the more likely explanation is that the photons entangle only when the electrons are in a corresponding state that permit entanglement.

  8. 8
    bornagain says:

    so you deny nonlocality nightlight?,,, Does this not now put you in the lunatic fringe group?
    I’ve heard that many journals have now refused to publish any more papers from the ‘lunatic fringe’ of deniers of non-locality.

    If it is any comfort, IDers are also considered ‘lunatic fringe’ in the main journals 🙂

  9. 9
    Mapou says:

    nightlight,

    In your first comment, you make it sound as if the messengers (entangled photons) actually make a decision as to whether or not the test is counted or not. This is not the case. Here’s what the paper says:

    The detection of two such photons constitutes the event-ready signal.

    The event-ready detector simply detects when both signals arrive. It’s just an error detector. The test cannot be conducted if only one photon arrives.

  10. 10
    nightlight says:

    @8 — “so you deny nonlocality nightlight?,,, Does this not now put you in the lunatic fringe group?”

    No one claims that there is actual non-locality, in the sense of transmission of anything (signal or matter/energy) faster than speed of light. There is only appearance of non-locality and there are different opinions about its origin. My position is that of quite a few notable physicists, including the most of the key founders of Quantum Theory, Planck, Einstein, Schrodinger, de Broglie, as well as surprising number of notable more recent physicists (Jaynes, Barut, Marshall, Santos, Nelson, Wolfram, `t Hooft etc). Vast majority of physicists, though, have not studied the problem at sufficient depth to care or matter about this subject.

    Even John Bell, who reformulated the older Einstein-Rosen-Podoslky “paradox” as non-locality problem via his inequality, acknowledges that his claim has absolutely unavoidable loophole (at least super-determinism, others think there are more possibilities than that), hence it’s not matter of wrong or right, but that of opinion and taste. Or rather, it is a question about how one sees future physics that will resolve some day the still open “quantum measurement problem” (which hinges on interpretation of Bell inequalities).

    @8 “I’ve heard that many journals have now refused to publish any more papers from the ‘lunatic fringe’ of deniers of non-locality.”

    There are some of course. It’s typical media, or subordinates/betas, reflex to stick to the perceived herd. Plus, the ‘quantum magic’ promised by the non-locality is much greater attraction for research funding than the non-magical alternatives. So, that’s about money and herd behavior, both of which tended historically to make the wrong bets. Such reflexive behavior is not a theory with which one can argue scientifically.

  11. 11
    nightlight says:

    @9 In your first comment, you make it sound as if the messengers (entangled photons) actually make a decision as to whether or not the test is counted or not.

    It’s not photons that decide but the coincidence logic (computer algorithm) that works on the results of measuring their degree of entanglement. The YES results from this detection logic finding full entanglement, NO from partial or imperfect entanglement. Results processing algorithm decides on that. The right column on page 3 gives more detail, although one needs to go to several cited earlier references to unwind the full meaning.

    In effect, the messenger (photons) which interacted with remote spins at A and B, carry purely classically (or non-magically) the information about those remote spins at A and B to the common location C and measurement on the messengers then yields algorithmically YES/NO decision.

    Such procedure is explicitly and grossly non-local. As noted, if some magician twins were to make any kind of telepathy claim based on demonstration arrangement like that, they would be laughed from the stage.

  12. 12
    Mapou says:

    One should note that Newtonian physics assumes nonlocality because it assumes that gravity is instantaneous. Coulomb also assumed that charge was propagated instantaneously. Even Einsteinian physics implicitly assumes nonlocality since the very concept of relativity (i.e., position A relative to position B) is inherently a nonlocal concept.

  13. 13
    bornagain says:

    nightlight, welcome to the lunatic fringe group 🙂

  14. 14
    nightlight says:

    @13 — you’re or anyone else is welcome to email to the lead author (his email is in the arXiv preprint) the link to this thread or just copy-paste my post #2, and see whether he can defend their ‘loophole free’ claim.

  15. 15
    bornagain says:

    nightlight, there is nothing wrong with being in the lunatic fringe. You just need to take one more small step and become a full fledged ID lunatic fringe instead of just a quantum lunatic fringe 🙂

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