Joy Christian wrote:or Macroscopic Observability of Fermionic Sign Changes Under Rotations:
Some of the readers of this forum may know that I have proposed a macroscopic experiment to test Bell's theorem itself (as opposed to merely observing violations of Bell inequality in quantum experiments). One of the papers where I have proposed the experiment is now published in the International Journal of Theoretical Physics. The published version of the paper can be downloaded from this URL: http://link.springer.com/article/10.100 ... 014-2412-2 (the preprint version can be found here)...
IV. PROPOSED EXPERIMENT
We now sketch a classical experiment which could, in principle, distinguish the geodesic distance on SU(2) from that on SO(3), as calculated in the previous sections (cf. Fig. 4). It can be performed either in the outer space or in a terrestrial laboratory. In the latter case the effects of gravity and air resistance would complicate matters,
but it may be possible to choose experimental parameters sufficiently carefully to compensate for such effects.
Q-reeus wrote:My question is, has there been any attempt in the final IJTP article to quantify the combined gravitational and aerodynamic perturbations, for a given experiment parameter set, and at least roughly show they will not swamp the rather subtle differences your idealized calculations predict? The aerodynamic influence in particular would seem a forbidding problem, unless clever statistical techniques can somehow extract the ideal results from the 'noise' so introduced. But it all gets down to expected order-of-magnitude effects to begin with.
Q-reeus wrote:Thanks for quick reply Joy. Fair enough. One or two suggestions if I may. Seems to me it would be not much extra trouble to simulate 'zero g'. By arranging for each 'explosion' to coincide with a free-fall drop in the entire apparatus. Easy to estimate the requisite free-fall time given the estimated free-flight time. So there would be periodic fall-then-lift-and-repeat. Cheaper than hiring time on the international space station surely!
Also, elementary scaling law arguments (basically, Reynolds number) suggest that minimizing aerodynamic turbulence implies miniaturizing the physical dimensions as much as feasible. Which coincidentally has the added benefit of upping the repetition-rate thus shortening the overall run time required to get meaningful stats. Better add - imho!
Q-reeus wrote:Always good to get a nod from a recognized authority. I'm not, but just one more thought. An obvious thing that separates a macroscopic analogue from the quantum one is degrees of freedom - far more in the former than latter. Having looked briefly at mitigating effects of gravity and turbulence, one other thing just come to mind is elastic vibrational modes. When hemispheres with 'randomly' oriented but coaxially aligned surface weights pop, it's inevitable some of the energy goes into vibrational motion, in addition to the ideally assumed purely linear + angular KE. So it would pay to try and estimate how material parameter specific modulus, combined with shell thickness, weights alignment relative to hemisphere axis, and planned 'explosion g-forces' add to generate vibrational energy. Hopefully just one or two dominant modes need considering. I imagine not much of an issue for reasonably stiff material and reasonably thick-walled shells, but only calculations will make that known with any certainty. Not getting any simpler!
Joy Christian wrote:Thanks, Jay. The triumph of truth has been bittersweet, but let us now hope that there is someone courageous enough to actually realize the proposed experiment.
Yablon wrote:Joy Christian wrote:Thanks, Jay. The triumph of truth has been bittersweet, but let us now hope that there is someone courageous enough to actually realize the proposed experiment.
Joy,
I would be interested in your comments on my recent paper at http://vixra.org/pdf/1411.0552v1.pdf, because it takes the view that FQHE is a direct experimental validation of fermion entanglement, and because your own work and proposed experiment is very much also entangled with entanglement.
Jay
Joy Christian wrote:I am glad you brought this up. In the published paper I have added two new paragraphs (reproduced below) concerning this issue, as a response to a referee's query:
Q-reeus wrote:Interesting observations. Your proposed experiment is based on spin measurements. The more one thinks about it, the more issues there are to deal with. As that passage reveals - there would be lots of finely timed measurements required for any run. And much post-processing to extract pertinent data. Given Alice-Bob Bell inequalities can manifest for either spin or linear polarized particle pairs, may there not be an analogous experiment involving purely linear polarization? If so, seems to me a considerably cleaner and simpler regimen might result. For instance it's easy to arrange for two arbitrarily rigid bars to fly apart with equal and opposite linear momenta. And for the bar axes to be precisely orthogonal to the velocity vectors. Not sure whether some form of randomization would be best at the bar or detector end of things, but all-in-all looks to have considerably fewer complications. Just some random ramblings.
Joy Christian wrote:No, two rigid bars flying apart with equal and opposite linear momenta will not do. There has to be relative rotation between the two constituents. Otherwise the difference between the topological properties of the rotation groups SU(2) and SO(3) will not manifest in the experiment (cf. the theoretical discussion in the paper).
That, however, does not mean that what I have argued theoretically is not applicable to the case of linearly polarized pairs of particles, such as photons. It just means that the theoretical analysis in the linear polarization case is somewhat different and more involved, as discussed in this paper: http://arxiv.org/pdf/1106.0748.pdf.
Joy Christian wrote:Hi Jay,
Thank you for the link. I just read your paper. I very much like your derivation of the FQHE from the orientation/entanglement relation. It is a yet another (and a very nice) example of the fundamental significance of that subtle relation. Just to clarify for other readers, this entanglement with environment has nothing to do with the quantum entanglement, or quantum mechanics. It is simply a not-so-obvious property of the physical space itself. In other words, there is nothing mysterious about it.
Joy Christian wrote:Both Richard Gill and Scott Aaronson have used all sorts of dirty political tactics to hurt me academically and financially. I therefore call upon the scientific community to have their professorships revoked when my proposed experiment finally vindicates my refutation of Bell’s theorem.
Q-reeus wrote:Joy, could you provide details here of precisely how the mechanics of exploding ball scenario would be realised in practice? That is:
1: The exact geometry envisaged.
2: Method of joining of the two hemispheres.
3: Method of pre-stressing them - i.e. a third entity such as internal coil spring or compressed air, or somehow just internal stresses in hemispheres.
4: What the pre-stressing is exactly - i.e. Purely compressive load (internal spring or compressed air), combination of compression and torsion (internal spring), or 'warping' of hemispheres in some way etc (no internal spring or compressed air).
5: Method of (presumably thermally) triggering the separation.
6: Will the method yield an expected constant ratio of linear to angular momentum for each run? My guess is no, assuming the planned random 'spot' weighting of hemispheres, coupling to initially linear separation impulses, is the sole method of generating angular momentum.
7: How your alternate 'squishy balls' arrangement would differ from above in each point mentioned.
Joy Christian wrote:These are all very good questions. I don't have answers to them at the moment, because the answers will very much depend on the actual singlet system used in the experiment. As we speak, various alternatives are being considered and discarded by experienced experimentalists for one reason or another. As you say (and unlike the ignorant claims made by Richard Gill elsewhere), although doable according to David Weinland this is not going to be an easy experiment to realize in practice.
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