Talk:Afshar experiment/Archive 30

message: I think all this quite un-necessary, as it pushes bad meanings. Everyone knows that arXiv is pre-print. Redundancy of such info, is like underline the fact, with possibly bad meaning. Imagine what will look-like to put after Unruh's and Motls's posts in brackets the following remakr: (web blogs). Is it aesthetic? Is this extra info manifesting good intention. Will anyone vote for inserting this (web blogs) after Unruh's and Motl's posts? And what about characterization of Drezet's preprint? Why it has no label? And what about putting After Afshar's two proceesings this labels "(proceedings)" and after the New Scietist and Cramer's Analog column this label (yellow press)? I vote for removing all this extra categorization of sources. One can check them without any prejudice and decide for himself. Danko Georgiev MD 13:51, 28 March 2007 (UTC)
thread_title:  "pre-print" labels for arXiv 

message: The whole section was voted for deletion, as it was written by editors, who even don't have any scientific contribution to QM or at least to Afshar's experiment. Still I expect to see Carl Looper's forthcoming paper promised in 2006, yet until then, I don't think that specific critiques section must be 3 times shorter than the non-expert written ongoing debate section. Danko Georgiev MD 10:06, 29 March 2007 (UTC)
replies: text: I agree. Delete the whole thing. But someone else needs to do it - but without destroying the links. Re - scientific contribution. It is true that I haven't completed my paper but there is far more material I need to go through than a re-exposition of the QM formalism. I'm writing from the point of view of information theory (a well defined science) and in particular signal theory - and even more specifically, - semiotics. The main problem is this. In terms of the QM formalism alone, one could argue that no "interference effect" can be said to have taken place in the Afshar experiment since the shape of the wave function, which normally determines the presence/absence of an interference effect (at the detector site) is determined only by the apertures and lens/detector arrangement - the wires playing no role whatsoever in shaping the wave function. And since the shape of the wave function, at the detector site no longer carrys any intrinsic interference information (other than minor fourier components) one must conclude that no "interference effect" is demonstrated. But if one is to claim an "interference effect", then one must look wider than the formalism, back in the setup - which is where Bohr is otherwise pre-occupied. And sure enough - there are the wires. We can't erase our knowledge of the wires - but the wave function does - insofar as it never carrys any information regarding the wires in the first place. What we find is that it is the combination of our knowledge regarding the wires (a pre wave function structure), and the information embodied in the  data (the intensity level) , plus our understanding of the wave function, which collectively construct our conclusion that an "interference effect" is demonstrated. But this can't be demonstrated by the QM formalism. It can, however, be demonstrated in terms of what Bohr is talking about. And what Bohr is talking about, as well as Heisenberg, involves a good deal of theory beyond the formalism. And to expose such requires a good deal of research which I can only lightly touch upon here in the hope that someone else is capable of picking up on it. For everyone else they must wait for the paper and reponder their equations. --Carl A Looper 23:27, 29 March 2007 (UTC)
thread_title:  Ongoing debate 

message: There was an error in the introduction regarding the Greenberger-Yasin relationship. I corrected the text to factually reflect my claims that is mentioned in section 5 of the Found. Phys. paper. Here's the new text with the changes in boldface: "...appears to be in accordance with the standard predictions of quantum mechanics, however, it is claimed to violate the Englert-Greenberger duality relation." -- Prof. Afshar 12:48, 29 March 2007 (UTC)
thread_title: Introduction

message: Kastner writes:
:Nevertheless, even with the grid removed, since the photon is prepared in a superposition S, the measurement at the final screen at t2 never really is a "which-way" measurement....
That's about as clear as can be that she doesn't belong in the "grid erases info" camp but in the "never any WWI" camp. I think it will be necessary to move her and to resurrect that point of view from the footnote back into the regular text. Any comments before I do that? --Art Carlson 19:45, 29 March 2007 (UTC)
replies: text: Dear Art, my regards, but Kastner's argument is flawed. It is NOT the superposition that erases the which way. Imagine AS AFSHAR POINTED OUT the two non-overlapping beams, for example arm 1 and 2 of the Mach-Zehnder interferometer, or the two slit beams before they overlap i.e. very close to the slit. Yes, they are superposied in the form \Psi = \alpha_1 |1> + \alpha_2 |2>, however because |1> and |2> are NON-OVERLAPPING i.e. orthogonal, at this stage the ww info is NOT erased, as these two wavefunctions [kets, |1> and |2>] do NOT manifest interference effects. Only after the overlap region the ww info is erased. This is clearly expressed in the equations 3 and 4 in my published article. As you have PhD in physics, you can check for yourself the calculations, they are not too complex after all. Danko Georgiev MD 04:43, 30 March 2007 (UTC)
replies: text: We are not discussing here whether Kastner is right or not, simply that her argument is improperly characterized in the current version. In addition, I don't think your description here is accurate. She is not saying that the superposition erases which-way-information, but that the wave function always contains  both "ways" - at the slits, at the wires, in front of the detector, all the way up till the collapse of the wavefunction in the detection process. --Art Carlson 07:27, 30 March 2007 (UTC)
replies: text: Dear Art, the which way concept is one-to-one correspondence concept. It has nothing to do directly with superposition of paths, i.e. much more other stuff is needed in order to prove the required bijection. Superposition existent or not, by itself is not directly linked to idea of bijection. For bijection, you must at first define two sets mathematically, then you must verify they have the same cardinality, and then describe a mapping. See bijection for details. I had the impression that Cramer was major consultant of Castner, so I thought that Kastner supports Cramer's view which are exactly clear for which way. Of course all these objections from this group are math inconsistent, so I am not surprized that confusions arise. p.s. feel free to classify Kastner's work any way you like. And reply to Afshar, yes there are two camps of objections, the fact that Kastner does not fit anywhere, is simply because her analogy is hardly seen or understood by anybody, as it is provably incorrect. In contrast Unruh's setup is crystally clear in disproving Afshar's analysis, however not in the way originally proposed by Unruh. Danko Georgiev MD 08:33, 30 March 2007 (UTC)

text: The "grid erases info" was put there by Danko to create an illusion of two major camps! The fact is the arguments presented by Unruh, Motl, Kastner, Drezet and others in that section are varied, subtle and usually contradictory to the other critics' argument. Kastner is using Cramer's Transactional Interpretation discussing an allegedly analogous experiment using Spin 1/2 particles and Stern-Gerlach apparatus. I have previously discussed the lack of analogy between my experiment and her suggested one's at the APS March 2006 meeting chaired by Prof. Greenberger, and separately my colleagues have responded to her in http://arxiv.org/abs/quant-ph/0702210. Her argument is very different from the fringe DQD argument, which is questioning the conservation of momentum argument espoused by Einstein and later used by Wheeler discussed in the article on Wheeler's delayed choice experiment. I suggest we remove the "grid erases info" from the text, and leave the fringe DQD argument in the footnotes, until they publish in a reputable peer-reviewed journal. BTW/ Unruh is a very famous and well-respected theoretical physicists who worked with Hawking and Davies (see Unruh effect)...-- Prof. Afshar 20:03, 29 March 2007 (UTC)
replies: text:  And Tabish Qureshi is famous and well-known researcher, who has disproved many other incorrectly solved foundational problems in QM. Now it seems to have spotted another incorrect solution done by Afshar et alia, that has been properly solved and math inconsistency revealed. Danko Georgiev MD 08:36, 30 March 2007 (UTC)

text:  Drezet, I am "copying" Afshar's argument, as it is one of my favourite ways to lead discussion, use the tools of the opponet, and force him into self-contradiction. Please comment on Afshar, not me. BTW, acceptance date with 2 years delay, is NOT a criterion either. I am exhausted to point out that science is to be decided in scientific way. Danko Georgiev MD 11:41, 30 March 2007 (UTC)
replies: text:  You guys, have nice time here. Continue to be "objective" wiki-editors, I will not lose my precious time here. I VOTE for Afshar being able to edit the article any way he likes, and retract my previous vote for him to be banned from editing the Critique section. Regards to all, Danko Georgiev MD 11:47, 30 March 2007 (UTC)
replies: text: Probably no one will object to your removing the reference to your work, but I hope you realize that the editors have every right to put it back if they want to. --Art Carlson 12:46, 30 March 2007 (UTC)
thread_title:  Kastner 

message: Qureshi writes:
As expected, there
has been skepticism towards Afshar’s experiment, and
a heated debate is currently going on7,8,9,10,11.
7 “Why the Afshar Experiment Does Not
Refute Complementarity” R. E. Kastner,
arXiv.org:quant-ph/0502021.
8 “Logical analysis of the Bohr Complementarity Principle in Afshar’s experiment un-
der the NAFL interpretation” R. Srinivasan,
arXiv.org:quant-ph/0504115.
9 “Complementarity and Afshar’s experiment” A.
Drezet, arXiv.org:quant-ph/0508091.
10 “Afshar’s Experiment does not show a Violation of Complementarity” O. Steuernagel,
arXiv.org:quant-ph/0512123.
11 “Entanglement and quantum interference” P.
O’Hara, arXiv.org:quant-ph/0608202.
I was always a bit worried about the possibility that our choice of criticisms could be biased, so I am grateful for a verifiable selection. We already have Kastner, Drezet, and Steuernagel. I will now add Srinivasan and O'Hara. --Art Carlson 09:34, 31 March 2007 (UTC)
thread_title:  additional references 

message: Thank you to both Art and Carl. The new specific critiques section is now logically structured, and carries useful information regarding the crux of each author's criticism. My hat's off to Art for having spent a good deal of time and effort to actually read and reflect upon each entry. Now, from a NPOV standpoint, I believe it would be necessary to inform the reader of my rebuttals to each. But before that, I'd like to ask one of the editors to add a small graphics and short description of an experiment (explained in the AIP paper) that was performed to simplify the experiment and use the conservation laws more clearly. I call it the Crossed Beams experiment in which no imaging lens is used. Please let me know who would like to take on this task, and I will provide the graphics that needs to be reformatted to the Wiki version. I'm not well-versed in the process myself! We discuss the related text here first. Thanks. P.S Qureshi paper should be properly flagged as a fringe argument, one which Unruh and all experts in the field reject. More importantly, it belongs in the article on Wheeler's delayed choice experiment since he actually criticizes Wheeler's setup and arguments, not mine... -- Prof. Afshar 14:18, 31 March 2007 (UTC)
thread_title: Recent improvements