Is quantum mechanics a complete theory of nature?

[Cthugha]

I have a copy of the manuscript and will see what it says.

Just to make my point clear: The author should somehow verify that the detector he uses is indeed a linear one for the range of intensities he is looking at. Generally speaking the photon number distribution in some detector area will be a Poissonian distribution around some mean value. For a detection event to occur one either needs a certain amount of photons within the coherence time of the light (for coherent detection) or during some characteristic timescale of the detector (for incoherent detection) to be present. As soon as the mean photon number becomes similar to the photon number needed for a detection event, non-linearities can and will occur due to the Poissonian nature of the photon number distribution. However, this is a detector effect. It could for example result in vanishing side peak structures or have similar effects.

2. The photon is defined as a wave-packet function whose mean energy is given by hbar times an average over its frequency components. This supports the idea of many superposed fields acting on the detector.

This is not the typical definition of a photon. Which book describes it this way?

4. The argument that a SPAD only detects single photons is a clear objection to these arguments; however, it was defined to be that way and due to uncertainty there is no way to positively distinguish between the two possibilities.

Due to uncertainty? Typical clump bunch models are easily ruled out as they cannot explain the joint detection rates at several detectors for non-classical light states. If you do not like the original antibunching paper, a more didactical one was published by Grangier:

P. Grangier, G. Roger, and A. Aspect, "Experimental evidence for a photon anticorrelation effect on a beam splitter: A new light on single-photon interferences", Europhys. Lett. 1, 173-179 (1986).

You need to find a model that violates inequality (7) in order to be in line with experimental observations. That is not possible with classical wave models and that is also the point constantly ignored by the clump-crackpot community.

 

[lugita15]

If you do not like the original antibunching paper, a more didactical one was published by Grangier:

P. Grangier, G. Roger, and A. Aspect, "Experimental evidence for a photon anticorrelation effect on a beam splitter: A new light on single-photon interferences", Europhys. Lett. 1, 173-179 (1986).

If anyone is interested, attached is that paper.

 

[nortonian]

Just to make my point clear: The author should somehow verify that the detector he uses is indeed a linear one for the range of intensities he is looking at.

The experiment with low intensity light by Panarella was not carefully thought out. The physical model he used is a clump model and leads to not very sophisticated experimental procedures. The film used is Type 47 Polaroid high speed film which may seem to be the proper choice. However, a study of starlight photography by Kowaliski indicates that “the use of a slower film can further improve the appearance of the signal.” Only one type of light was used, from a He-Ne laser, but incoherent light should also have been tried for comparison. The data was not normalized for intensity. In other words, as filters were inserted in the output of the interferometer the exposure time should have been increased an amount sufficient to maintain the same total recorded intensity. The visibility is known to decrease with increasing time of exposure, but no one has shown whether it varies linearly. Nevertheless the claim that interference effects were eliminated must be taken seriously.

This is not the typical definition of a photon. Which book describes it this way?

Loudon

You need to find a model that violates inequality (7) in order to be in line with experimental observations. That is not possible with classical wave models and that is also the point constantly ignored by the clump-crackpot community.

I am not talking about classical wave models, rather about photons with classical fields that superpose. In previous posts I have taken the position that non-locality in Bell theorem tests is a field effect and is therefore due to classical properties of light. If those tests can be successfully performed using very low intensity light from which classical field properties such as interference have been eliminated then qm could make the claim of non-locality and not before. The non-locality experiments depend on the precise meaning of “photon” and “one-photon state”, but as has been pointed out here, by Loudon, and by others there is some ambiguity in the definitions.

I have no dispute with the calculations of qm or the experimental results, but there are serious problems with how initial conditions were defined and therefore with the conclusions drawn from them. No one knows exactly what is going on at the microscopic level and to make pronouncements on reality and locality on such a shaky basis is rash, as though they are simply properties of matter like mass or anything else.

 

[Cthugha]

Only one type of light was used, from a He-Ne laser, but incoherent light should also have been tried for comparison. The data was not normalized for intensity. In other words, as filters were inserted in the output of the interferometer the exposure time should have been increased an amount sufficient to maintain the same total recorded intensity. The visibility is known to decrease with increasing time of exposure, but no one has shown whether it varies linearly. Nevertheless the claim that interference effects were eliminated must be taken seriously.

Well, as I said, it would be most important to check the response linearity of the film first before jumping to conclusions. Most people doing research in optics make the mistake of wrongly assuming a linear detector response in a regime where it is in fact not linear at lest once in their lives - at least this is my experience. Most of these learn an important lesson from that. Checking incoherent light may not be too interesting. It may be interesting to compare thermal light with coherence times shorter and longer than the typical 'response' time of the film, though.

I am not talking about classical wave models, rather about photons with classical fields that superpose.

Ok, but the field associated with a photon is classical anyway (is that the point in Loudon's book you mean?). Non-classical signatures arise only at the intensity level. This can be seen easily in the fact that g^{(1)}, the field-field correlation function does not carry any signatures of non-classicality and cannot be used to distinguish classical from nonclassical states, while g^{(2)}, the intensity correlation function does carry such signatures. Classicality of a system with respect to some quantity roughly means that a measurement of that quantity does not disturb the system. This is trivially true for field correlation measurements, but not true for intensity correlation measurements.

In previous posts I have taken the position that non-locality in Bell theorem tests is a field effect and is therefore due to classical properties of light.

But this position is not tenable. The closest completely classical analogue to SPDC emission you can find is some phase conjugated classical light field showing classical phase conjugated correlations. See e.g. B. I. Erkmen and J. H. Shapiro, "Ghost imaging: from quantum to classical to computational" in Advances in Optics and Photonics, Vol. 2, Issue 4, pp. 405-450 (2010) for a brief review of phase sensitive coherence properties. However, using this kind of light field in Bell tests does not lead to any violations of Bell inequalities. Obviously, also non-classicality in general is very well known to not be a field effect, so it is very strange to attribute non-locality to field effects.

If those tests can be successfully performed using very low intensity light from which classical field properties such as interference have been eliminated then qm could make the claim of non-locality and not before.

I do not understand what you mean. In some sense interference is eliminated because (momentum)-entangled photons are necessarily spatially incoherent and cannot show perfect entanglement and a visible double slit interference pattern under the same experimental conditions. One can demonstrate that these properties are complementary (Phys. Rev. A 63, 063803 (2001)).

The non-locality experiments depend on the precise meaning of “photon” and “one-photon state”, but as has been pointed out here, by Loudon, and by others there is some ambiguity in the definitions.

Is there? A single photon state is one for which g^{(2)}(0)=0. There is no ambiguity about that.

No one knows exactly what is going on at the microscopic level and to make pronouncements on reality and locality on such a shaky basis is rash, as though they are simply properties of matter like mass or anything else.

I do not see where the basis is shaky.

 

[nortonian]

But this position is not tenable. The closest completely classical analogue to SPDC emission you can find is some phase conjugated classical light field showing classical phase conjugated correlations. See e.g. B. I. Erkmen and J. H. Shapiro, "Ghost imaging: from quantum to classical to computational" in Advances in Optics and Photonics, Vol. 2, Issue 4, pp. 405-450 (2010) for a brief review of phase sensitive coherence properties. However, using this kind of light field in Bell tests does not lead to any violations of Bell inequalities. Obviously, also non-classicality in general is very well known to not be a field effect, so it is very strange to attribute non-locality to field effects.

Classicality of a system with respect to some quantity roughly means that a measurement of that quantity does not disturb the system. This is trivially true for field correlation measurements, but not true for intensity correlation measurements.

You are speaking of non-local classical which is the accepted interpretation of what it means to say classical. I am speaking of local classical. The first can be measured and represented quantitatively, the second cannot be but may perhaps be revealed by physical means, as for example by low intensity light when photons become statistically independent.

I do not understand what you mean. In some sense interference is eliminated because (momentum)-entangled photons are necessarily spatially incoherent and cannot show perfect entanglement and a visible double slit interference pattern under the same experimental conditions. One can demonstrate that these properties are complementary (Phys. Rev. A 63, 063803 (2001)).

Formulations of the meaning of classical include implicit prejudices such as saying that classical absorptions of energy occur gradually or interference occurs over the coherence volume. The possibility that they are local phenomena is not considered and so a weakened model of classical is compared to qm and rejected.

I do not see where the basis is shaky.

I want only to present an alternative view. One that is local and physical. If it is inadequately expressed it reflects on my capabilities not on the overall picture. I defer to the majority view not because it is correct but due to its intricate design.

 

[Cthugha]

I still do not get it. Almost all of your statements are at odds with experimental results. Do you have ANY justification for your crude theories?

The first can be measured and represented quantitatively, the second cannot be but may perhaps be revealed by physical means, as for example by low intensity light when photons become statistically independent.

Statistical dependence or independence does not depend on the mean intensity, but just on the 'character of your light field'. Photons in a coherent light beam are always statistically independent irrespective of the mean intensity. Photons in a thermal beam always have the tendency to bunch. Your claim is plain wrong.

Formulations of the meaning of classical include implicit prejudices such as saying that classical absorptions of energy occur gradually or interference occurs over the coherence volume. The possibility that they are local phenomena is not considered and so a weakened model of classical is compared to qm and rejected.

Argh. None of this is correct. Classical can be used as in opposition to quantized or it can mean that nonperturbative measurements are possible. The paper of Grangier explicitly shows that there are states for which both of these descriptions fail. 'Local' or 'non-local' does not even play a role when considering these arguments.

I want only to present an alternative view. One that is local and physical. If it is inadequately expressed it reflects on my capabilities not on the overall picture. I defer to the majority view not because it is correct but due to its intricate design.

Your view is at odds with experimental results. Therefore it cannot be physical. By the way this is not a forum for personal theories.

 

[nortonian]

I still do not get it. Almost all of your statements are at odds with experimental results. Do you have ANY justification for your crude theories?

See attachment and explain quantum mechanically why there is greater intensity of field in the middle of the spark discharges. These are unretouched photos of Tesla coil discharges.

Statistical dependence or independence does not depend on the mean intensity, but just on the 'character of your light field'. Photons in a coherent light beam are always statistically independent irrespective of the mean intensity. Photons in a thermal beam always have the tendency to bunch. Your claim is plain wrong.

Sorry, change to physical independence. Light does not interfere or interferes less as is apparent from lower visibility or disappearance of fringes because with low intensity light photons are separated physically from each other.

Argh. None of this is correct.

We are speaking different languages.

 

[Cthugha]

See attachment and explain quantum mechanically why there is greater intensity of field in the middle of the spark discharges. These are unretouched photos of Tesla coil discharges.

And this is supposed to show what? If you have the field distribution, know how and where photons are emitted in these discharges and know your detector response function you can trivially calculate what you will see on a picture. You do not need fringe physics for that.

Sorry, change to physical independence. Light does not interfere or interferes less as is apparent from lower visibility or disappearance of fringes because with low intensity light photons are separated physically from each other.

Are you still discussing that Panarella junk science claim? It has not been published in a credible peer-reviewed journal and there are dozens of peer-reviewed publications contradicting the results presented there. Panarella is well known to be a fringe scientist who sometimes performed serious work, but very often crossed the border to just claiming nonsense. Panarella just measured his detector response function and claims that it is a property of the light field itself. There is a reason why he did not get his results published in a serious outlet.

We are speaking different languages.

Nature speaks very clearly in terms of experimental results. Of course one can muddy the waters by claiming things which are not tenable like Panarella did, but why should one do so.

Again, this is not a forum for discussing fringe or crackpot physics and also not a forum for personal theories as is explicitly described in the forum rules you agreed to. Unless you have some peer-reviewed publications backing up your daring claims, I do not see how this discussion could take a sensible course and I think it is better to just quit this discussion.

 

[Kal-El]

Question? Would it be possible to re-write Bell's Theorem in terms of some other type of particle and test that particle under the given theorem?

 

[DrChinese]

Question? Would it be possible to re-write Bell's Theorem in terms of some other type of particle and test that particle under the given theorem?

This has been done many times and with many different configurations. There are a lot of things that can be entangled (which means they violate a Bell inequality at some level). So try these:

http://arxiv.org/abs/1202.5328

http://arxiv.org/abs/1202.4206

Or better just look at some of these (this is a hodgepodge but you can still see the idea):

http://arxiv.org/find/quant-ph/1/AND+abs:+bell+abs:+test/0/1/0/all/0/1?per_page=100