- #26

Cthugha

Science Advisor

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They give analogies. The differences are huge. For example in the diffraction and interference paper, quantities which are depend on the field intensity in standard diffraction/interference experiments now depend on amplitude. The experiments are nice to look at, but they are just analogues, not more.See Couder's experiments (analogous to dBB) -without any nonlocality, they give clear intuition for:

- interference in double-slit experiment (particle goes a single way, but "pilot" waves it creates go through all paths - leading to interference): http://prl.aps.org/abstract/PRL/v97/i15/e154101 ,

- tunneling (the field depends on the whole history, making that getting through a barrier is practically random): http://prl.aps.org/abstract/PRL/v102/i24/e240401 ,

- orbit quantization (to find a resonance with the field, the clock has to perform an integer number of periods while enclosing an orbit): http://www.pnas.org/content/107/41/17515 ,

- "classical Zeeman effect" (Coriolis force instead of Lorentz): http://prl.aps.org/abstract/PRL/v108/i26/e264503.

Proper intuition? I would say no. The physics is not the same, though there are similarities. Concrete quantum phenomena? Antibunching and entanglement for starters.Do you disagree that they give proper intuition about quantum phenomenas?

Please refer to a concrete quantum phenomena which indeed needs some nonlocality or nonobjectivity?

Do you have any peer reviewed publications supporting your claim? Then please post it. Otherwise please stop making such claims. By the way, the delayed choice quantum eraser does not require any retrocausality. We have plenty of topics on this experiment here.Thanks. Violation of Bell inequalities shows only that our natural past->future "evolving 3D" intuition is wrong ... what is also obvious from other fields of physics: using Lagrangian mechanics and is broken e.g. in quantum retrocausality: Wheeler's or delayed choice quantum eraser experiments.

This violation is not in disagreement with living in a field theory governed by Lagrangian mechanics (before or after quantization).

That is wrong. Quantum dots are the semiconductor equivalent of atoms. They are not harmonic oscillators (or just to the same degree that atoms are) and show pretty much the same mode spectrum as atoms do. The length for atoms depends on the transition used. See the references in the article above.Ok, http://prl.aps.org/pdf/PRL/v108/i9/e093602 [Broken] ... but it is about quantum dots: harmonic oscillators.

I completely agree that waves produced by harmonic oscillators should be very different from standard optical photons: results of deexcitation of excited atom ... what are "time lengths" for them?

Loosely speaking, a 50/50 mixed state means that upon many repetitions, you get result A half of the time and result B half of the time, but within every repetition, the state is A and B all the time, not a superposition of both. It may be beneficial to read up on those basics before thinking about entanglement at all. There is not much chance to really understand it without knowing the difference between superpositions and mixed states.Sure, but still does the mixed state in his quantum mechanics means that the cat is not objectively dead or alive?

Yes, they are indistinguishable unless you use a very light mirror. Distinguishability requires an irreversible interaction, which would mean that the mirror ends up in a state orthogonal to its initial state. If a photon gets redirected, the momentum transfer is well within momentum uncertainty of the mirror, so that it does not end up in a state orthogonal to the initial one. There are people in cavity optomechanics using very light cantilever mirrors where things may be different. For a typical MZ- or Michelson interferometer, however, the two paths are indistinguishable.So when two paths in M-Z interferometer are indistinguishable, you get interference?

But are they really indistinguishable?

Reflecting photon by mirror means momentum transfer - doesn't final situation of photon going one or second path differ by final momentums of mirrors?

You could measure it by placing these mirrors floating in vacuum and finally measuring their positions after some time.

I have nothing to add to what I wrote above.Quantum mechanics is h-order expansion of classical one by the wave nature ... in Feynman path integral you usually start with classical trajectory and make variation around it ...

So you say that this expansion allows energy to travel through curved trajectories without momentum exchange?

Like while reflecting by mirrors in M-Z interferometer?

There would be nothing wrong with the photon having such a broad spectrum, but experiments show that it does not. So this idea is simply ruled out.But what's wrong is about having broad spectrum?

I never said anything against this picture. It is a bit simplistic though.Take electron, twist it by 180deg, changing its spin by 1: e.g. from -1/2 to +1/2 ... Noether theorem says that the used angular momentum has to create twist-like wave.

Exactly like behind a marine propeller, but this time the medium (EM field) has no viscosity - such twist-like wave can travel without dissipating ... e.g. finally getting to another electron and twisting it 180 deg.

What's wrong with this picture?

You claimed this "process" lasts just a single cycle of the em field. This is demonstrably completely wrong.I meant only that everything in internal dynamics of a single atom takes time/evolution - and so we should be able to ask how much time deexcitation lasts - changing orbital angular momentum or twisting spin of electron.

I already responded to that. What exactly is the remaining question you have?Accordingly to Noether theorem, this angular momentum changing process should produce wave carrying this angular momentum (optical photon) - of spatial length being time length multiplied by the propagation speed (c).

Why it is not so simple?

Yes. If it was "just a wave", there would be no need for quantization....is photon something more than just a wave carrying energy, momentum and angular momentum - to compensate differences in deexciting atom?

It is a general problem of massless bosons. The problem arises due to moving at c and the absence of a rest frame. If you want the full math, you can show this by having a look at the representations of the Poincare group in the massless boson case, but I am sure that there are people on these forums way better at that than I am.Just a quick question about localization: is the crucial difference between the electron and the photon that the photon can't be prepared in a localized state because it is always absorbed in measurements or is it something else?

Needless to say, there are some alternative suggestions for constructing alternative position operators that still work for photons, but one has to keep in mind what they really mean. Although it sounds easy, position may become a tricky concept.

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