Talk:Afshar experiment/Archive 2

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Classical ray optics is not Quantum Mechanics

Dear prof. Afshar,

As I have added special section where I explain where Unruh is wrong, actually I also say that your error is essentially the same - you use the classical ray model of light and this is where your error comes from. In the discussion above you advised me to see the web page: http://webphysics.davidson.edu/applets/Optics/intro.html

and I have checked that link today. What everybody can see is exactly the CLASSICAL RAY MODEL OF LIGHT AND THE CLASSICAL MODEL OF LENS ACTION. Actually you tell me nothing new - I already have analogous figure in my revised paper. Soory to tell you but the classical formula 1/a + 1/b = 1/f, where a - distance to object, b - distance to image, f- focal length is not the only way to explain the production of images. I will give you simple counterexample, and i hope you will understand now how serious my critique is.

Suppose we have double lens system 1f-lens-1f-1f-lens-1f. The classical ray model will give you again right image of the object. Folowing this classical model you may consider that there is which way info. However the Fourier optics provides alternative explanation - you have double applicaion of Fourioer transform, so you end up with the same image as predicted by the classical model. However in this second case you don't have which way info.

Wish you nice reading of my paper. I am sure that it will not be losing of time by you.

Danko

for recent opinions or results from the ongoing discussion check also: http://www.geocities.com/dankomed/afshar.htm

Misc

My question is not related to Danko Georgiev, and please don't kill me because I am at the moment not a professional physics student (I am math and electrical engineering). It appears from the article that Unruh's main objection is that Afshar is interpreting two measurements as one in which the light acts as both a wave and a particle. Unruh says it is two different measurements and in one (the detector) it seems particle, and in the other it is a wave since the light is interfering around the wire. If Unruh is right, then what constitutes a legitimate measurement that would show a violation of complementarity? A single measurement in which you get wave and particle behavior? What does 'a single measurement' mean? Bananaclaw 03:05, 16 May 2005


Dear Bananaclaw, Please post your question on my Blog [1] , and I'll answer it there. Let's keep these questions off of the Wikipedia pages. Thanks.-- Afshar 17:11, 16 May 2005 (UTC)


Dear Bananaclaw, If you check out any good textbook in optics you will see that classical ray optics is just approximation of wave optics. Concerning you question - yes, Afshar is right that IF there is which way, then the photons CANNOT avoid the grid and there WILL BE loss of photons. Unruh, as well as Motl are on the wrong way - my thesis: the PRESENCE OF THE GRID does not change anything in the experiment, while Unruh and Motl suggest that the grid "mixes the two channels - S1->D1 and S2->D2". Unruh and Motl theses are both wrong, and they are also wrong that without the grid there is "which way" info. If you don't believe me see the Yoon-Ho Kim's paper at arXiv: quant-ph/9903047, where is simply explained that LENS does not give you which way info in the double slit scenario. For more check my web paper. Danko [16 may 2005]

Major revision

I've attempted to cut the Gordian knot of confusion surrounding this experiment with a major rewrite/expansion of the article. There are three separate issues here:

  • The claim that Afshar's experiment violates heuristic principles of complementarity. Since there is no precise statement of such principles, there is room here for reasonable people to disagree.
  • The claim that Afshar's experiment contradicts certain interpretations of quantum mechanics. This is simply false. The only debate here is between those who understand the interpretations of quantum mechanics and those who do not. I don't know whether Afshar has made a claim along these lines. If he has, he probably has misunderstood what an "interpretation of quantum mechanics" is, based on the broader meaning of the word "interpretation" in English.
  • The claim that Afshar's experiment contradicts a particular quantitative principle of complementarity, given in his paper. This is presumably either true or false, but I have no idea which. Can anyone fill in this information?

-- BenRG 13:28, 23 May 2005 (UTC)

Dear BenRG, I moved your contributions to another page Afshar Experiment and the Interpretations of Quantum Mechanics dedicated to the interpretations issue. Since the paper itself is only concerned with the Complementarity issue, it would be helpful to separate the two to avoid confusion.-- Afshar 18:22, 23 May 2005 (UTC)

Yes, the paper only discusses the complementarity issue. But surely you're aware that people are misrepresenting your work as having much broader implications for the interpretations of quantum mechanics. Given all the confusion and misinformation out there, the issue should certainly be addressed here. Furthermore, the article as it stands does not discuss only complementarity. It makes specific claims about the Copenhagen, many-worlds, and transactional interpretations, and those claims are false. At the very least allow me to replace that paragraph with a paragraph linking to the new article you created.
I notice that on the talk page for the new article, you describe my changes as biased. Please tell me specifically what you think is biased. I made a great effort to avoid any bias in what I wrote, and in fact I never expected you to disagree with it. -- BenRG 20:25, 23 May 2005 (UTC)
Dear BenRG, Forgive me for this belated reply. I was tied up with rediculous exchange with Lumidek. Thank you for trying to clarify what I have and have not claimed. But since there are major errors in your contribution, please allow me to suggest my corrections as soon I can. For now, I am sure the page will not be deleted, which give me a chance to edit it. Best regards.--Afshar 13:28, 23 May 2005 (UTC)

Original research

Most of the controversy section looks like an active debate on these pages, original research and so unencyclopedic at this stage. Should it be removed and replaced with a two line summary and external links?--Henrygb 16:41, 23 May 2005 (UTC)

Dear Henrygb, According to Wikipedia guidlines, delineated in Original research, at worst Afshar experiment falls under the category of "the ideas [that] have become newsworthy: they have been independently reported in newspapers or news stories", due to the numerous news media oultlets that have covered this work, and hence can be posted on Wikipedia. However I do agree with your sentiment that the Controversy section seems somewhat like a back-and-forth discussion rather than an encyclopedic article. Perhaps the Controversy section should be put together along with the Afshar Experiment and the Interpretations of Quantum Mechanics page under a new page titled Afshar Experiment: Contoversy and Interpreations? I would appreciate your suggestions to that end.--Afshar 18:38, 23 May 2005 (UTC)
For what it's worth, my recent contribution, since removed, was in part an attempt to summarize and encyclopedify the article. I left the existing back-and-forth discussion in place only because I didn't have time to read, understand and summarize it. I think this page should remain for the reasons Afshar gave: it is an experiment that has received a lot of publicity in the popular press. I think that people who come to Wikipedia for more information ought to find a well-written article which, among other things, explicitly mentions and corrects some of the errors that have been made in other media accounts. That's what I was (am) trying to do. -- BenRG 20:54, 23 May 2005 (UTC)

Opponents and Proponents

Dear CSTAR, naming just the opponents (who have been answered by a proponent, i.e. Prof. John Cramer) is unfair. See this New Scientist link which shows the last reply to all those critics on August 21, 2004. The list of proponents of my conclusions includes Prof.s/Dr.s Antony Valentini, Dan Cole, Gregg Jaeger, Eduardo Flores, Ernst Knoesel, Robert Perry, Colin Bruce, F. Cardonea, R. Mignanib, W. Percontid, A. Petruccib, R. Scrimagliod, and many others whose names escape my memory right now. There is further evidence in support of my conclusions to be announced at the Vaxjo conference in a couple of weeks. This is a subject that by default all physicists would be opposed to at the beginning and as time progresses more are convinced as new evidence comes to light. Bottom line, naming Pro/Opponents at this time (beyond the critiques mentioned in the Controversy section) is unnecessary, and possibly misleading, especially in light of the fact that all those you listed have been shown to have been too rash in their response, as they did not have enough info on the experiment to make the correct judgment. Regards.--Afshar 06:01, 26 May 2005 (UTC)

As you know, the August 21 letter was from John Cramer, the same individual who suggested your interpretation supported his transactional interpretation of QM. In any case your list of Prof.s/Dr.s are not individuals whose letters (if any) appeared in the New Scientist. It is only fair that the individuals included in the edit you reverted be named to balance your citing the New Scientist.
naming Pro/Opponents at this time (beyond the critiques mentioned in the Controversy section) is unnecessary, and possibly misleading,
This is disingenuous. Wikipedia is not meant to cover original research, and its inclusion here without appropriate disclaimer is misleading.
as they did not have enough info on the experiment to make the correct judgment.
Oh really? Are you the judge of that?
Based on this exchange, this article clearly does not satisfy the NPOV policy of WP.
Regards--CSTAR 11:37, 26 May 2005 (UTC)
Dear CSTAR, It seems that now you are being judgmental! "This is disingenuous" NO!: (i) I am NOT sure if those individuals still believe what they wrote about before my refutation which John Cramer explained in his Aug. 21, 2004 letter to NS. That is why I said it may be misleading. You may wish to contact them before their names get permanently associated with this stance. (ii) "Oh really? Are you the judge of that?" YES! I am the judge of that and rightly so, BECAUSE: NS editors told me exclusively about the only clear shortcoming of the article, which was the fact that it did NOT mention the actual physical dimensions of the experiment and its components. Consequently most readers had assumed that the wires were as closely spaced as a regualr wire grating. In reality the spacing between the wires were 2-3 orders of magnitude larger than the spacing on a regular grating and thus produced much less beam mixing (hence no reduction in which-way info reliability). I am sure you were not aware of this fact (because I was the only one who got the e-mail from NS editors on this issue), and therefore you assumed that I was being biased in my decision regarding the inclusion of their names as opponents. Given YOU accept responsibility on possible assignment of views to individuals whose opinion may have changed after Cramer's letter, please go ahead and post those names. Further, if this remedy resolves your NPOV issue, please remove the flag, and if it doesn't tell me what else you have a problem with. Regards--Afshar 14:08, 26 May 2005 (UTC)

Latest additions

Dear CSTAR,

Sorry for the fact that I was not logged in. Certainly the edit was mine. What I have really tried to edit initially is to put the NPOV banner on Afshar's article, but Afshar removed it. Since Afshar is writing his own biased entry, and since the main article is in a form of discusion, I decided to write down a "popular explanation" where Afshar is wrong. Also note that truth has nothing to do with encyclopedic style. Since the article describes the experiment, it should not have any of the interpretations neither Afshar's, nor anyone else's. And in order to be usable the intro that says that his experiment is "optical which way one" should be deleted, because this does not correspond to scientific truth. I will not try to recover my entry because I could be considered as biased therefore I hope that someone else will put a kind of banner on Afshar's article that will denote that Afshar's entry is used as advertisement, not as sci entry. Indeed by the conventional standards if someone promotes his own work in popular press, but if this work has not passed peer-reviewing and has not being published in orthodox sci journal, then the someone of interest possibly is charlatan or quack.

--Danko_Georgiev_MD 1:24, 27 May 2005 (+2.00 GMT)

The anonymous edits by User:212.91.163.193 (Danko Georgiev) hardly conform to an encyclopedic style. Regardless of the merit of the contents, it should be rewritten in a more suitable style or deleted.

The existence of this article and the problems which it has led to are a clear indication that the WP policy of no original research is a wise one. However, I am not a policeperson, so I won't request it be deleted.

Given that this article exists (unfortunately) , I don't care what Afshar's claims are. He could claim that the Moon is made of green cheese for all I care. However, given the constraint of this article's existence, the article should

  • Report the fact of Afshar's experiment and his (and Cramer's) interpretation;
  • Report that many qualified people don't believe his interpretation (I personally believe that MOST people believe his interpretation is wrong). In particular, the controversial (and in my opinion exceedingly unwise) decision of the New Scientist to feature this experiment should be counterbalanced with dissenting letters to the editor, of which there were many
  • Report the experimental setup (roughly as is now the case)
  • Report dissenting opinions with links to various webpages, rather than the extensive discussion. For Afshar's "rebuttals", reference to his weblog suffices.

This article should probably be placed on RfC.

--CSTAR 15:36, 26 May 2005 (UTC)

I moved the comments by User:212.91.163.193 (Danko Georgiev) to the end of his original nonesense edits above. He has absolutely no credibility as outlined in the past by Unruh's rejection of his non-ideas in support of my analysis of the Fourier optics of imaging lens. As for your belief that "MOST people believe his interpretation is wrong" I must say that in my interactions with colleagues at different academic gatherings, I find that MOST have not formed an opinion yet. On New Scientist's decision to publish the article, you should know they interviewed many experts in the field and that this process took about 9 months. They asked me to respond to the experts' critique and after they were satisfied that the experts could not defend their objections, they decided to publish the article, that is hardly unwise. That said, I have found you more objective than other commentators here, and therefore would appreciate if you go ahead and implement those changes as you suggested, and I will react if I feel there is a factual error by alerting you.--Afshar 18:33, 26 May 2005 (UTC)
Dear CSTAR, The issue of a lens (with no wires) providing which-way information in its image plane has been an accepted physical concept since Heisenberg's famous Microscope proof of the Uncertainty Principle. My setup in which there are no wires present is an exact replica of the one used by John Archibald Wheeler to demonstrate complementarity, and the images were considered to contain the which-way information. Both Unruh and Motl agree with the fact that the images produced by a lens (with no wires) provide which-way info. Danko is saying that regardless of the presence of the wires there is no which-way info. in the images, which is absolutely wrong as discussed by Unruh above. So, I have absolutely no problem with the which-way idea being ascribed to me, but it quite literally started with Heisenberg, and Bohr himself. I can give you the ref.s if you wish.--Afshar 00:28, 27 May 2005 (UTC)
That's not Danko's point. Of course the term or concept which-way was not invented by you. However, to say as you claim the experiment is indeed a which way experiment is tantamount to accept your POV. Both Unruh and Motl agree with the fact that the images produced by a lens (with no wires) provide which-way info. Well yes that's clear and well-known. And reading Danko's latest entry and I find no support for you interpretation of it, i.e., Danko is saying that regardless of the presence of the wires there is no which-way info. However, whether or not that is what Danko meant is a Red-Herring.
Regards.--CSTAR 23:48, 26 May 2005 (UTC)


CSTAR, we may be splitting hairs here, but I reworded the paragraph to make it accurate: because "which-way is preserved even when the wires are there" is indeed my idea, and so the paragraph is OK. I must point out again though, this is not an approval of Danko's erroneous point. In response to your "I find no support for your interpretation of it," just to make sure you realize I am not putting words into Danko's mouth here's a direct quote from above entries by Danko: "Certainly there is error in Afshar’s interpretation, and the problem is that he is claiming without proof that there is which way information even when there is no grid before the lens.--Afshar 01:08, 27 May 2005 (UTC)


  • Dear CSTAR and dear Afshar,

Yes, what I am claiming is that the image at the image plane of the lens does not contain "which way" info even if there is no grid. This is very clearly stated, and I don't understand what is not clear here. If someone of you wants to send me refs where this topic is discussed then I will glad to read them. This will just add more people to the fallacy list [so far Afshar, Motl, Unruh, and Drezet, fall in the category that defends the 'which way' without the grid]. This is however the main point - please prove it!!! i have provided clear mathematical definition of complementarity, and I have provided very concrete mathematics. Actually if there is 'which way' the density matrix must be mixed one, and if 'there is no which way' AS I CLAIM then the density matrix will be of pure state. The two different density matrices are in principle testable. In the first case you cannot recover interference in any way, in the second case you may clearly visualize interference! Simply if the density matrix is that of mixed state, then if you put the detector sigma_2 out-of-focus i.e. say two meters behind the image plane what you will see is just a clumping pattern [like the prediction of the Rayleigh formula], and IF I am right and the density matric is that of a pure state then out-of-focus you will obtain clear interference picture.

I have consulted all the current textbooks in QM and Quantum Computation, therefore I can argumentedly defend my position with mathematics. So far Afshar is blowing air under pressure, and I would like to ask him, please show where is your refuttal of my Fourier interpretation becase I have not seen it yet.

Danko Georgiev [28 may 2005]

  • Questions for homework posed to Afshar:
    • 1. Formulate in mathematical language the complementarity principle [hint: I have done in the last section of this talk, so check you answer]
    • 2. Write down the density matrix for the 'which way' and the density matrix for 'no which way' [hint: read my paper [2]]
    • 3. Answer the question can the mixed state dendity matric be experimentally discerned from pure state density matrix [hint: in pure state the density matrix rho = rho^2, while if you have mixed state this equation does not hold].
    • 4. Tell me how you exactly prove that there is 'which way' if there is NO GRID before the lens. [hint: try not to use classical ray optics ; answer: in QM this is inprovable].

Self promotion and other issues

Though this article did not in a technical sense originate with Afshar (User:Samboy is listed as the originator), its contents were mostly material he had written about his experiment in other articles on WP. This article is not an autobiography (indeed very little information seems to be available to produce such an autobiography other than he is now visiting at Rowan University and is a member of IRIMIS); however, since it mostly pertains to Afshar's work, the policy Wikipedia:Autobiography is applicable here. In particular, the following paragraphs apply:

Similar principles apply to articles about works that you are primarily responsible for — the company you run, the website you started, the book you wrote. Use common sense.
Also, realize that anything you submit can be edited. Several autobiographical articles have been a source of dismay to their original authors after a period of editing by the community, and in at least three instances have been listed for deletion by their original authors. In some cases the article is kept even if the original author requests otherwise.

The other general policy issue I would like to point out is Wikipedia:No legal threats which Afshar has clearly violated above. The fact that Lubos Motl behaved in offensive ways is no excuse and should be dealt with in other ways (and preferably, completely ignored).

Wikipedia is not peer-reviewed and to pretend that the open nature of its editing process is a replacement for peer-review is nonsense. In particular, the controversy section with various pros and cons is not a reasonable place to evaluate Afshar's claims. The correct position should be complete skepticism until we have a peer-reviewed journal article in a scholarly physics journal. The active involvement of Afshar himself in the editing process of this article is highly suspect and should stop, in my opinion. Afshar is free to do what he likes, since I cannot nor can anybody else, short of a ban (which won't likely happen) enforce any of this.--CSTAR 02:32, 27 May 2005 (UTC)

Dear CSTAR, "its contents were mostly material he [Afshar] had written about his experiment in other articles on WP" This is wrong! Look at the history of the mentioning of this experiment on Wikipeida. I had absolutely nothing to do with the very initial entries made on different mostly QM-related pages. I later tried to make the entries as accurate and fair as I could, evidenced by the inclusion of many different critics' comments, and added links that seemed relevant. "[Afshar's] editing process of this article is highly suspect and should stop" Surely you are not suggesting I have no right to set the facts straight?!--Afshar 04:02, 27 May 2005 (UTC)
Dear Shahriar.
Surely you are not suggesting I have no right to set the facts straight?!
Don't frame the question, please. Fallacy of many questions.--CSTAR 03:22, 27 May 2005 (UTC)
As to your other remark, I admit that tracing the source of every statement in this article is not something I have done. But your edit history in all the precedents to the current article is extensive, to say the least.--03:29, 27 May 2005 (UTC)

Mathematical clothing of complementarity

The complementarity principle TELLS US how to manipulate quantum amplitudes. This can be checked in my paper [3]. Briefly complementarity says:

1. If two wavefunctions (e.g. psi_1 and psi_2) are representing indistinguishable particle state then in order to compute the final probability you should add psi_1 + psi_2 and then square the sum. So P = |psi_1 + psi_2|^2

2. If you have distinguishable particle states then you first square then add. In this case P = |psi_1|^2 + |psi_2|^2

Therefore if Afshar busts complementarity THEN he busts the mathematical formalism of Quantum mechanics

This can be checked in any conventional textbook of Quantum Mechanics, so Afshar's claim that he disproves ONLY complementarity, but not Quantum Mechanical Formalism is ridiculous!!! So dear prof. Afshar, please write me down the mathematical structure of what you call complementarity. The complementarity principle as is understood in conventional textbooks is telling us how to manipulate quantum amplitudes in order to obtain probabilities. What you understand under the term complementarity is absolutely un-imaginable for me, and possibly for everyone who has studied QM.

Danko Georgiev (27 May 2005)

Final edits

I propose to remove the remainder after "complementarity" with something like

Various critiques of Afshar's claim have been posted on the internet by the well-known physicists Unruh of UBC link and Motl of Harvard link as well as others links. Afsher addresses some of these in his blog link.

A few words in the introduction bother me, particularly "many physicists" are skeptical which I believe should be "most physicists" are skeptical. However, I have not conducted a scientific poll, and I am sure that fact would be brought to my attention.

I hope this is the last I ever see of this page.

I also hope this serves as a lesson to anybody else that has the bright idea of creating a page on unpublished research. --CSTAR 16:33, 29 May 2005 (UTC)

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