# Opposition to quanatum mechanics? **URL:** \ **Category:** Factual Questions\ **Created:** [June 9, 2016, 11:03pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976 "2016-06-09T23:03:48Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [June 11, 2016, 6:50pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/41 "2016-06-11T18:50:47Z")
> [@Half\_Man\_Half\_Wit](#): > > I haven’t read this in full as of yet, but it starts out boldly claiming that ‘locality is dead’ thanks to quantum mechanics, which is simply not true. Rather, any proposed theory that augments quantum mechanics with additional parameters needs to be **local** ; but we don’t know if any such theory is true. Quantum mechanics itself is perfectly local. Was that a typo for “any proposed theory that augments quantum mechanics with additional parameters needs to be **non-local** ”? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 11, 2016, 7:04pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/42 "2016-06-11T19:04:33Z")
Newton built on generations of experimental data: Galileo’s results that gravity resulted in an acceleration, not a velocity, and many astronomers who measured the distance to the Moon and other celestial objects. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [June 11, 2016, 7:05pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/43 "2016-06-11T19:05:07Z")
> [@Riemann](#): > > Was that a typo for > “any proposed theory that augments quantum mechanics with additional parameters needs to be **non-local** ”? Err, yes, thanks for catching that. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [June 11, 2016, 7:08pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/44 "2016-06-11T19:08:07Z")
**Half Man Half Wit** , can I just ask if I’ve got this right - The Bell’s Inequality experiments say local realistic theories can’t account for the data, so we have standard QM = local & non-realistic de Broglie-Bohm = non-local & realistic And maybe the superdeterminism loophole, saying the experiments aren’t valid because the sampling isn’t random, the universe is a conspiracy in some sense - is this taken seriously? ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [June 11, 2016, 7:10pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/45 "2016-06-11T19:10:28Z")
> [@Half\_Man\_Half\_Wit](#): > > Err, yes, thanks for catching that. Phew, I’m just relieved that I haven’t totally lost the plot… ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [June 11, 2016, 9:25pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/46 "2016-06-11T21:25:33Z")
> [@Riemann](#): > > **Half Man Half Wit** , can I just ask if I’ve got this right - > > The Bell’s Inequality experiments say local realistic theories can’t account for the data, so we have > > standard QM = local & non-realistic > de Broglie-Bohm = non-local & realistic > > And maybe the superdeterminism loophole, saying the experiments aren’t valid because the sampling isn’t random, the universe is a conspiracy in some sense - is this taken seriously? Whether quantum mechanics should be called a local theory or not depends on your definition of ‘local’ and it is not difficult to find examples of QM being described as a non-local theory. It also depends on your view on how QM should be interpreted. Realism is usually a property assigned to interpretations of QM, rather than to the theory itself, but again it is not like there is a rigorous definition of ‘realism’. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [June 11, 2016, 10:52pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/47 "2016-06-11T22:52:19Z")
> [@Riemann](#): > > **Half Man Half Wit** , can I just ask if I’ve got this right - > > The Bell’s Inequality experiments say local realistic theories can’t account for the data, so we have > > standard QM = local & non-realistic > de Broglie-Bohm = non-local & realistic > > And maybe the superdeterminism loophole, saying the experiments aren’t valid because the sampling isn’t random, the universe is a conspiracy in some sense - is this taken seriously? Well, it’s an issue of interpretation, depending on what exactly you take ‘standard QM’ to be. Many Worlds interpretations, for example, are both local and realistic: they get around Bell’s theorem, because it assumes that measurements have definite outcomes, but in MWI, every outcome occurs. On probably most takes on ‘standard QM’, however, it’s local according to most definitions of locality—you can’t send superluminal signals, there’s no action at a distance, and the local description is independent of whatever happens on distant systems. As for Bohmian mechanics, the issue is far more clear: it’s explicitly nonlocal—the quantum potential, which tells the particles how to move, depends on the coordinates of all particles simultaneously, so whatever happens to one may instantaneously influence all of the others. Regarding realism, most commonly, particle positions are definite, and hence, one can treat them realistically; however, other properties, such as spin, don’t have independent reality—rather, whether a spin detector, say in a Stern-Gerlach experiment, clicks, is determined by the position of the particle within the wave packet. The superdeterminism issue is a little more thorny again. Few people take it seriously, on the grounds that it is difficult to see how one even would do science in such a case: after all, we never observe ‘how the world really is’, but merely, what we are constrained to observe by the superdeterministic rules. Furthermore, it has less explanatory capacity: quantum mechanics predicts the value of Bell inequality violations, and only a violation consistent with this prediction is observed. E.g., in the case of the CHSH-inequality, QM yields the value 2.83 \> 2, while a superdeterministic theory could just as well yield values up to 4. Thus, why we only see violations consistent with the quantum bound remains unexplained. However, a prominent exception to this is Nobel laureate Gerard 't Hooft, who proposes an explanation of QM in terms of a cellular automaton model. It hasn’t found much resonance within the community, though. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [June 11, 2016, 11:01pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/48 "2016-06-11T23:01:02Z")
> [@ftg](#): > > I am both opposed and unopposed to QM. Not me, I prefer thinking outside the box. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [June 11, 2016, 11:19pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/49 "2016-06-11T23:19:46Z")
> [@Half\_Man\_Half\_Wit](#): > > On probably most takes on ‘standard QM’, however, it’s local according to most definitions of locality—you can’t send superluminal signals, there’s no action at a distance, and the local description is independent of whatever happens on distant systems. One sense in which one can consider even standard QM to be nonlocal is that even if you have full information about all of a system’s subsystems, it doesn’t follow that you have full information about the total system—there’s additional information in the correlations that doesn’t reduce to information about the system’s parts. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 12, 2016, 12:50am UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/50 "2016-06-12T00:50:29Z")
> [@](#): > > Quoth **eschereal** : > > Not me, I prefer thinking outside the box. Think inside the box, because it’s bigger on the inside. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 12, 2016, 5:31am UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/51 "2016-06-12T05:31:44Z")
> [@chappachula](#): > > What about Newton’s discovery of gravity? Didn’t he think of the revolutionary theory first? > And only a century or two later other people did the experiments to prove it? > > I thought that Newton simply proclaimed his theory: that the force which determines the trajectory of the planets in orbit was the same as the force which determines the trajectory of a cannonball. To support his theory , he showed the math; but did he use experimental data in any way? Johannes Kepler started with meticulous data on Mars’ path through the sky and, in an amazing feat without computers or sophisticated math, was able to derive [Kepler’s (empirical) Laws of Planetary Motion](https://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion). The “proof” of Newton’s laws of motion and gravitation was that it explained Kepler’s empirical Laws. There were a few scientists who posited an inverse-square law for celestial gravitation independently of and shortly before Newton did. _But they were all reacting to Kepler’s empirical discovery_ (in particular, that orbits were ellipses). But this doesn’t fully answer your question. Might Newton have developed the same laws in the pre-Keplerian world when orbits were thought to be circular? I don’t know. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 12, 2016, 5:40am UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/52 "2016-06-12T05:40:51Z")
By the way, I think that the [three-photon GHZ experiment](http://web.physics.ucsb.edu/~quopt/ghz.pdf) leads to a simpler example of quantum weirdness than Bell’s Theorem. I mentioned it in an earlier thread: > [@Please explain Bell's theorem](https://boards.straightdope.com/t/please-explain-bells-theorem/713399/24): > > … > In the GHZ experiment, an H’/V’ test is performed on one photon. > If it is H’, the other photons will match each other if both are submitted to an H’/V’ test; but they will mismatch if both are submitted to an L/R test. > If it is V’, the other photons will mismatch each other if both are submitted to an H’/V’ test; but they will match if both are submitted to an L/R test. > > _ **Given these results, all 64 possible settings of the 6 “hidden” bits are impossible** _, no probabilistic argument is needed – all the probabilities must be zero. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 12, 2016, 12:13pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/53 "2016-06-12T12:13:52Z")
I don’t have time to read through all of that right now. Does it allow for the possibility that the “hidden variables” might be more complicated than 6 bits? ---
**Author:** ![JacobSwan](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@JacobSwan](https://boards.straightdope.com/u/JacobSwan)\ **Post date:** [June 12, 2016, 12:44pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/54 "2016-06-12T12:44:50Z")
No one is opposed to the typo in the thread title? ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 12, 2016, 12:48pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/55 "2016-06-12T12:48:08Z")
> [@Chronos](#): > > I don’t have time to read through all of that right now. Does it allow for the possibility that the “hidden variables” might be more complicated than 6 bits? 😕 The basic idea is the same as the version of the EPR paradox usually treated in Bell’s Theorem. Bell’s result is that a probability which must be at least 0.333 _if common-sense causality applies_, is instead only 0.25. The GHZ result is that a probability which must be 1 _if common-sense causality applies_, is instead 0. The GHZ experimental setup is more complicated than Bell’s. But the paradoxical result is clearer and more “satisfying.” ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [June 12, 2016, 3:07pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/56 "2016-06-12T15:07:29Z")
> [@JacobSwan](#): > > No one is opposed to the typo in the thread title? There’s a no zero probability it’s not a typo. ===== Slight hijack here … _ **SHOULD** _ there be opposition to quanetum mechanics? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 12, 2016, 10:19pm UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/57 "2016-06-12T22:19:56Z")
I asked only because a lot of lay explanations of entanglement-related weirdness do assume that hidden variables must be only one bit each, but it’s easy to come up with hidden variable models which are slightly more complicated, and which avoid those overly-simplistic arguments. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 13, 2016, 3:22am UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/58 "2016-06-13T03:22:41Z")
> [@Chronos](#): > > I asked only because a lot of lay explanations of entanglement-related weirdness do assume that hidden variables must be only one bit each, but it’s easy to come up with hidden variable models which are slightly more complicated, and which avoid those overly-simplistic arguments. Perhaps my referring to the 6 _potential_ binary observations as 6 “hidden” bits was the source of confusion. Reread my brief summary with that substitution. Both GHZ and the usual Bell’s experiment involve the orientation of a mirror; treating the polarization result as two “hidden” bits is tied to the fact that the experimenter uses just two orientations, no? In that sense, I think the treatments are equivalent. On the other hand, if you want to posit a more complex “hidden” system, e.g. 137 bits instead of 6 bits. what difference would it make? The six bits I described would still be derivable from the 137 bits; and the “paradoxes” would apply with the same argumentative authority. TL;DR: Your objection, if any, applies equally to the usual Bell’s Theorem set-up. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 13, 2016, 3:33am UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/59 "2016-06-13T03:33:37Z")
… And of course the whole discussion of a local hidden-variable system is counterfactual. The point of the E-P-R paradox, and its variations including the GHZ experiment, is that such systems do _not_ describe reality. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [June 13, 2016, 3:43am UTC](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976/60 "2016-06-13T03:43:32Z")
**septimus** : Is it really that certain? There are some decent minds who still think that a hidden-variables model might work. That isn’t as foolish as, say, creationism or flat-earthism, is it? Even some of the posts in this thread seem to accept hidden variables as an abstract possibility, although far from a favored one. [Previous page](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976.md?page=2) [Next page](https://boards.straightdope.com/t/opposition-to-quanatum-mechanics/756976.md?page=4)