Official Afshar Experiment Blog Questions 2

You are in [Official Afshar Experiment Blog Questions 2]

Please post your questions here after March 12, 2005. Soon I will organize a comprehensive FAQ page as well.

Thanks!

Dear All

I would like some clarification to start this new stream of posts.

Entanglement applies to two or more particles even if one of them is used as input to the two slit experiment, it is not applicable to single particle experiments.

Afshars experiment is conducted in such a manner that it is the setup of the experiment coupled with the conservation of momentum that allows us to know exactly which slit the photon has gone through.

Whilst knowing which way the photon has gone we also manage to show the absense of interference with both slits open via intererence minima.

This is essentially it is it not ?

Dear quantum enforcer

"Whilst knowing which way the photon has gone we also manage to show the absense of interference with both slits open via intererence minima."

This is a contradiction. Interference minima show the presence of interference, not the absence.

Dear Quantum Mirror

By placing wires at the minima of interference we observe when both slits are open the absense of interference is what I mean.

Professor Afshar,

How big could the wires have been and still record sharp complimentarity? What radiant flux criteria would determine detection/nondetection of a minima?

The non destructive measurement of IP, I find as a breakthrough in itself, and possibly capable of many more discoveries.


Peter Tanguay

Dear quantum enforcer

"By placing wires at the minima of interference we observe when both slits are open the absense of interference is what I mean."

Did I wake up in a new universe when this became page 2? The name of the paper is: "Sharp wave and particle in the same experiment". The only way to show wave is to demonstrate that there "is" interference. There would be no minima without it. Minima show the presence of interference and therefore the wave. At the CCD we detect particles. This is how the experiment shows wave and particle in the same experiment.

Dear Peter Tanguay

"How big could the wires have been and still record sharp complimentarity? What radiant flux criteria would determine detection/nondetection of a minima?"

The size of the wires is not important. The experiment shows that the radiant flux is 80 times higher without interference. This number is more than sufficient to demonstrate interference as necessary for the conclusion that interference is present.

Dear Quantum Mirror

Sorry, obviously making a bad impression with my explanation of it. With only one slit open and the wires in place we get scattering of light and a reduction of the image intensity at the CCD. Then by opening the other slit the intensity of the image in restored because the wires are in the minima (almost a complete absense of light) of wave behaviour from two slits. Hence light intenisty is restored due to the wire not in fact blocking any light (or very little).

The CCDs are in addition still recording individual photons and hence "which path information".

Voila, Ware and Particle behaviour simultaneously. Well thats is essentially my understanding of it anyway.

Dear quantum enforcer

I see, you were using the word interference to mean interfering with the photons, not interference in the wave sense. Wrong choice of words in a physics experiment.

Dear Quantum Mirror,



I am not criticizing the size of the wire as too big for detecting a minimum. According to my calculations the present size of the wire influences the cos 2 α term in the Bessel function by only ± 3%. That is the largest difference that is within the accepted limit, for the final value of radiant flux to be considered unaffected. Otherwise stated, δ12 ≈ 0 for the coherent state. I am amazed that the wire could be so big. It spans 143μm with max positioning error, and is 200λ. I believe Afshar has accomplished his goal.


My point for questioning the size of the wire has a different goal. If the wire was at first 100 λ, and then increased to 200 λ, then one would not significantly decrease/increase knowledge of IP minima location. One would also simultaneously double his position knowledge of where the photon could not be. This is because the diameter of the wire is doubled. This simultaneous gaining of knowledge is at the plane of the wires not at the slits. This would violate Hiesenberg, as well as complimentarity. WWI at the plane of the slits is not involved for this question.

Do you see what I am saying? I am also interested in professor Afshar’s input.

Peter Tanguay

Dear Peter Tanguay

I will let prof. afshar have the definitive word on this but the way I see the experiment the wires are only there as a test to show that interference is present. With one slit open you have light sparkling on the wire and a reduced image at the CCD. With both open you have no sparkles and a complete image that compares to the image of one slit without wires. With calculation and trial and error probing we can work out exactly where the minima are located. I don't see that knowledge of minima location would pertain to complementarity or Heisenberg since with no changes to the equipment they should appear in the same place every time. We would always know that photons were not there.

To those of you who were suggesting that no previous experiments had simultaneously demonstrated particle and wave behavior, you should examine delayed choice experiments more carefully:

http://www.bottomlayer.com/bottom/kim-scully/kim-scully-web.htm

Dear Uncertainty Identity

The difference is very clear between the two experiments. The name of this experiment is:

"Sharp complementary wave and particle behaviours in the same welcher weg experiment"

In the mentioned quantum erasure experiment they have clearly demonstrated that wave disappears every time they have which-path information. From the article:

Figs. 3 and 4 show the "joint detection" rates R01 and R02 against the x coordinates of detector D0. It is clear we have observed the standard Young's double-slit interference pattern. . . .

Fig. 5 reports a typical R03 (R04), "joint detection" counting rate between D0 and "which-path" D3 (D4), against the x coordinates of detector D0. An absence of interference is clearly demonstrated. .

This paper clearly has wave and particle in the same experiment.

The last line above should have been which-path and wave in the same experiment.

Dear professor afshar

The pre-print: Attosecond double-slit experiment has arrived:

http://arxiv.org/PS_cache/quant-ph/pdf/0503/0503165.pdf

From the article: Of particular
importance for interpreting quantum mechanics have
been experiments with a single particle at any given time
in the apparatus [5, 6]. More recent work has illuminated
the fundamental importance of complementarity
in which-way experiments [7]

There is of course no reference to this preprint.

Which makes my Questions on 3/8 from this link much more valid.

http://irims.org/blog/index.php/questions/2004/09/25/questions_welcome#c494

Here is my question before from before the preprint was out:

They say the reason for interference in these experiments is because we can't know which of two peaks created the electron which then self interfered. I think they are reaching a bit too far here. I may be completely off base since I can't read the paper but could this also be explained as the two peaks created two electrons which interfered with each other? The single peak could only produce one. This sounds more reasonable than we can't know which peak created the electron so complementarity is put into action. Is there a QM reason this is not possible?


Now we see why the delay in printing this paper is important for physics and Professor afshar. So that papers such as these must explain their results using reasons other than complementarity!

Professor when you have time I would like to hear your opinion of this.

Dear All

New and very important pre-print has just arrived:

http://arxiv.org/PS_cache/quant-ph/pdf/0503/0503201.pdf

From the paper:

Their ingenious gating system allowed GRA to test, perhaps for the first time, quantum mechanical predictions for a single photon state. Interference is confirmed in the obvious way. The which-path predictions are also confirmed; the photon is detected in only one path. What we have shown though, is that a wave model (CIEM) can explain this result. It cannot therefore be concluded that the detection of the photon on one path confirms particle behaviour. In a particle model, the photon takes one path at the beam splitter and is detected in that path, whereas in our wave model the photon splits at the beam splitter, is nonlocally absorbed, and is again detected in only one path. Since the which-path measurement does not confirm particle behaviour, Bohr’s principle of complementarity is
also not confirmed, contrary to what is claimed by GRA. We conclude then, that GRA’s experiments confirm wave behaviour but not particle behaviour, so that complementarity is also not confirmed. We may further add, that if complementary is accepted Wheeler’s delayed choice experiments lead to very strange conclusions: either history is changed at the time of measurement, or history is created at the time of measurement CIEM, on the other hand, explains Wheeler’s delayed-choice experiments in a unique and causal way. It is perhaps fortunate therefore, that complementarity remains experimentally unconfirmed.

Is this experiment in any evidence that photons which take a definite path could possibly "interfere" with each other?

Dear Science Nunce

I am assuming your question is does this experiment show any evidence that photons which take a definite path interfere with each other?

Yes when they go through a double slit and are resolved by a lens.

Professor,

How did the presentation at the APS conference go? Was there enthusiasm or mostly criticism?

Peter Tanguay


Quantum Mirror,

thank you for the detective work in finding the latest relative preprints. Its great to see the latest relative events on the blog.

Peter

http://www.bottomlayer.com/bottom/kim-scully/Image7.gif

http://www.bottomlayer.com/bottom/kim-scully/kim-scully-web.htm

http://www.bottomlayer.com/bottom/kim-scully/Image5.gif

http://www.bottomlayer.com/bottom/kim-scully/kim-sc1.jpg


Dear Prof. Afshar, and dear readers,

I am personally very interested in Delayed Choice experiments and what puzzled me in Afshar's experiment is NOT the fact that he disproves "complementarity", but the STRONG CLAIM that the focusing lens provides "which way" information. I think the error comes from "misunderstanding" that the lens provides "which way" information, and surely this is not so.

I will post just a brief comment, and I hope that prof. Afshar will realize where his error is. Actually if Complementarity Principle was wrong, then NONE of the Heisenberg relations would be TRUE [for example you cannot measure of a quantum both position and momentum - the uncertainty relation is delta_x delta_p[x] > 1/2 h bar], and the whole quantum mechanics would be destroyed if Afshar's experiment was true. But there is fundamental error in it :

The lens does not provide "which way" information, because say detector 1 if counts a photon cannot say from which slit the photon passed - actually the photon passes trough both slits, then it interferes with itself and there is interference picture even when when you perform the experiment photon by photon. So photon self-interference IS NOT PROVE against complementarity and this is what is overlooked by Afshar. So my advice is that he withdraws his paper and publishes that his experiment is actually interpreted in the wrong way.

I provide the right argument against his conclusion, but you should read also the paper
"A Delayed Choice Quantum Eraser"
by Yoon-Ho Kim [1], R. Yu, S.P. Kulik, Y.H. Shih, and Marlon O. Scully
http://xxx.lanl.gov/pdf/quant-ph/9903047
Phys.Rev.Lett. 84 1-5 (2000).

and reviewed by Ross Rhodes here:
http://www.bottomlayer.com/bottom/kim-scully/kim-scully-web.htm

The argumentation is clear - the lens does not provide the "which way" information, and two possible pictures are possible - (i) interference or (ii) not interference. Please not the fact that here a single photon can "interfere" or "not interfere with itself" and this depends on whether the "which way" information is available.

Case (i)
http://www.bottomlayer.com/bottom/kim-scully/Image5.gif

Case (ii)
http://www.bottomlayer.com/bottom/kim-scully/kim-sc1.jpg

But how a 100% of which way information is obtained? Well, this can be done with prism, not with lens !!!!!!!!!!!! Note this, and major consequence at the end of this post.

http://www.bottomlayer.com/bottom/kim-scully/Image7.gif

So now because in the experiment listed above we work with entangled pair of photons, if the "which way" of the second photon is meausred we have "not-self-interference" of the first photon, and if the "which way" of the second is not measured the first photon "self-interferres".

If you read the mentioned paper by Kim et al. (2000) then you will see that lens does not provide "which way" information, and that Afshar is clearly wrong.

MY SUGGESTION IS THAT PROF. AFSHAR PUTS A PRISM TO DETERMINE THE"WHICH WAY" NOT LENS. BUT THEN THE INTERFERENCE PATTERN WILL DISAPPEAR IMMEDIATELY AND I CAN GUARANTEE THAT !!!

If there is not difference between prism and lens on their capacity to provide the "which way" or welcher weg information, then the experiment of Afshar SHOULD HAVE identical results when the lens is substituted with prism.

I hope prof. Afshar will not blame me that I have "cut the wings of the plane", because my critique is clear - he shows that there is "mixing of information" by detectors 1 and 2 about slits A and B and says that this "mixing" is 10^-6, but this is major loophole. There should be ZERO "mixing of information" about the "which way" in order the experiment to be valid, otherwise one can consider that the "mixing value" has increased > 10^-6, and that this increment depends on the experimental setup, and the "mixing" is varying between experiments.

How the photons "understand" the difference between the different systems is another topic and has to to with backward causality as suggested by Wheeler's delayed choice experiment and Cramer's interpretation.

CONCLUSION

If there is not difference between prism and lens on their capacity to provide the "which way" or welcher weg information, then the experiment of Afshar SHOULD HAVE identical results when the lens is substituted with prism. But my prediction is absolute failure to observe interference if Afshar put prism "after the grid". Note here that the prism is after the grip, not "before the grid". So the photons will "know" their future !!!

If there is prism after the grid, each photon will not interfere with himself when he passes in the space before the grid, and if there is lens after the grid the photon will interfere with itself in the space before the grid. So actually in the space before the grid the photon will "know the future" - whether there s lens or prism after the grid !!! :-)

At best, perfoeming the prism experiment by Afshar is EASY, and it will prove Complementarity at once, as well as Wheeler's delayed choice, and will destroy Afshar's WRONG conclusion.

Best,

Danko Georgiev

"Is this experiment in any evidence that photons which take a definite path could possibly "interfere" with each other? "

NO - lens does not provide "which information" so photons interfere and they do not have definite paths.

If they had definite paths then photons cannot interfere, and there would be diffraction from the grid.

If lens is substituted for prism arranged in the way shown by Kim et al. (2000) [web link in my previous post] then photons will have definte paths, but there certainly will be diffraction from the grid.

Sorry to disappoint all readers, but Afshar experiment is interpreted in the wrong way.

I am curious why John G. Cramer took Afshar's conclusions as evidence for the transactional model, because IF Afshar was wrong then all known interpretations of QM WOULD BE wrong! This is serious overlook by professor like John G. Cramer.

Typos:

"not provide "which information" should be red as:
"not provide "which way information"

and

"IF Afshar was wrong then all known interpretations of QM WOULD BE wrong!" should be read as

"IF Afshar was right then all known interpretations of QM WOULD BE wrong!"

Sorry for the typos.

Dear Danko Dimchev Georgiev, MD

Have you read the paper? There is a permanent link at the top of this blog. Prof. afshar has followed the exact QM proof using this lens as Heisenberg. Heisenberg's microscope proof is based on the imaging theory of a lens, in which the resolution limit of the lens directly enters the uncertainty relation as delta_x, the uncertainty in position. See Physical Principles of the Quantum Theory by Heisenberg or any other textbook on QM for that matter. The paper follows the rules of QM and would not even be under consideration for publication if it did not. Prof afshar has been on a trip to europe to the APS conference and is very busy writing a book and designing the next set of experiments. My answers to this blog are mine alone and are answered to the best of "MY" ability to answer them. I am not associated with Shahriar S. Afshar in any way and don't hold him accountable to my answers. I am a visitor to this blog just like you and when I answered that the lens resolved the which way information, it was a simple answer to a garbled question. Not in any way meant to replace the paper which Shahriar S. Afshar has written.

Dear Danko Dimchev Georgiev

You say that:"Please not the fact that here a single photon can "interfere" or "not interfere with itself" and this depends on whether the "which way" information is available."

What is the physical force or mechanism that prevents interference and which way information in the same experiment?

Dear Danko Dimchev Georgiev,

I am also a visitor, however I am a Senior Optical /Laser Engineer for over 20 years. I can assure you that the lens images the pinhole/slit. This is an accepted method to provide which way information .

The photon interfering with itself is, in my opinion, classic double speak by advocates of Copenhagen. They want it both ways. A wave interferes with itself. A photon is a localized event. However in order for CI to be true , they also say the photon has an extended nature. The photon has never been directly obeseved to have an extended nature, that is just what is necessary for the interpretation CI. The photon is only directly observed at detection or emmission. This alone should be enough to say TI is the preferred interpretation.

I beleive the Transactional Interpretation. Because when only waves are present through both slits, there is no need for WWI here, and consequently no conflicts. Most parties beleive TI does not conflict with Afshars results. These parties include the previously mentioned Kastner and John Cramer. I believe Professor Cramer and CIEM proponents advocated this experiment because a wave model is a best fit with the results.

Afshar is foremost an experimentalist, and need not concern himself with interpratation. his conclusions are justified under presently accepted CI theory.

Peter Tanguay

Please note that I am medical doctor, not specialist in mathematics. I think you have not read the essay about the "Delayed choice quantum erasure" that is why my point is not clear. You should look at least the web links [from my previous posts] with the pictures of images from lens and prism!!!

You ask what prevents a photon to interfere with itself, when there is "which way" information. Well, this is a kind of tautology, because "which way" means that you have measured photon travelling in a straight line. If this is the case then there could be no interference [wave-like motion].

Does lens measure "which way"? IF you see the experiment performed by Kim et al. you will see that THIS IS NOT ALWAYS SO!

Lens may measure "which way", but also "may not measure which way" :-) Both type of statistics are seen on Kim et al. experiment. You better read the review of Kim et al. experiment first.

Soon I hope I will be able to write down the mathematics that explains where exactly is the error of Afshar. It will be published online.

Best,

Danko

What about prof. Cramer,

I have notified him that Afshar interpretation is NOT consistent with delayed choice, and so it seems that the interpretation is against TI. But surely ordinary QM DOES PREDICT no diffraction from the grid, exactly what Afshar has shown. But this is because the lens does not provide which way info. I am curious why prof. Cramer has not spotted the wrong conclusion by Afshar?!

Dear Peter,

The APS meeting was very reassuring. Prof. Greenberger (famous in the foundations of physics circles) called the experiment "very beautiful", and said that he would include it in his textbook, if he writes one. He was happy to accept both measurements (sharp interference and which-way) in the same experimental setup. He had a little confusion regarding the quantum erasure aspect of my experiment, which we are hammering out right now...

Dear Dr. Danko Georgiev,

I understand you are excited about your views, and I respect that. But I must say, to put it mildly, you are not "even wrong"! A lens CAN provide which-way information if one observes its image plane. The lens can ALSO provide information on momentum distribution (Fourier transform of the position space) in the Fourier plane, which for a beam of collimated light is the focal plane. The Kim et al. paper uses the Fourier plane to observe one of the photon pairs, so that they can choose a particular wave-front propagation direction. They use a Glen-Thompson prism because it separates orthogonally polarized signal and idler photons produced by the down conversion crystal, not because it acts like a lens!!! ...

I do not wish to be blunt, but I'm afraid untill you formally study QM and put your arguments in terms understood by all physicists, I shall refrain from further addressing your posts, in accordance with the conditions announced at the top of this page. To that end, you may find some posts in (Questions 1) page instructive.

Best regards.

"note that I am medical doctor, not specialist in mathematics."

That is certainly clear.

" I think you have not read the essay about the "Delayed choice quantum erasure" that is why my point is not clear. You should look at least the web links [from my previous posts] with the pictures of images from lens and prism"

Yes the paper was brought to our attention last month and I thoroughly reviewed it and saw no conflict with this paper.

With commentary by Ross Rhodes:
QM predicts that if which-path information is not available at the time of measurement, the pattern will be an interference pattern, as though wave-like photons passed through both slits and "interfered with themselves" to produce the distinctive interference pattern of hits. This is the case at detector D0 at all times.

If you read the "commentary" which is all this web site is, he mentions QM predicts several times. If you read the original paper at this url:

http://xxx.lanl.gov/PS_cache/quant-ph/pdf/9903/9903047.pdf

They don't say that QM predicts, they say at the first of the paper: Over the years the two-slit interference experiment has been emphasized as a good example of the enforcement
of complementarity.

What you are reading in the commentary is wrong. QM has not made the predictions as he keeps mentioning. complementarity is the predictor. What you are saying is: Complementarity can't be wrong because complementarity says it can't be wrong.
This is the same circular logic that has kept complementarity alive all these long years without physical reason or logic.

Dear professor Afshar,

I found your experiment original and interesting and the controversy surrounding it is really an occasion to sharpen our concepts on the nature of light.
I have however a simple comment.
I agree with you when you say that when the grid is removed and one hole (or slit) is closed, the detection enables you to know WWI.
But I think this is not true anymore when you put the grid (and one of the slits is still closed). Because then, what you get in the detection plane, is in a way the Fourier transform of the transmittance function of the grid, that is to say the typical diffraction pattern of a grating (having possibly many orders). So even if the thickness of the wires is small, you have indeed diffraction. This means that a photon detected on detector 2 is likely to come from slit 2, but there is a probability that the photon comes from slit 1. (This probability depends on the relative thickness of the wire that determines the "duty cycle" of the grating) .
So it is unclear to me whether you really get WWI from the experiment with the grid. Could you show us what is seen by the detector 1 in the figure 8 b) ? Because I am pretty sure you have some signal there (even weak) ! This would help !

Thank you very much
Best Regards

Dear Hugues de chatellus

As Prof Ashar has stated many times. Due to the conservation of linear momentum the experiment demonstrates that particle to detector is guaranteed to be the way prof Ashar staes it to be.

Dear hugues de chatellus

From the preprint:( link at the top of this page for PDF)

Fig. 8(c) on page 33 of the preprint shows the configuration in which both pinholes are open, and the WG is present. The data show that the attenuation of the transmitted light in this case is negligible, R = (-0.1± 0.2)% indicating that the WG has not absorbed or reflected a measurable amount of light within the margin of error, thus establishing the presence of dark fringes at 1 s , so that V=1. It is also evident that the loss of the resolution of the image compared to the decoherent case is negligible. There is a very good agreement between the theoretical value of 0 = Coherent R and the observed value R. This is compelling evidence for the presence of a perfectly visible IP (V=1)

As you see the loss of signal is R=(-0.1± 0.2)%. If the data from the unused CCD were included it would be a small fraction of this amount and as you can see negligible in the outcome of the experiment.

Dear hugues de chatellus

I just realized you were talking about fig. 8b. In this situation the prof. is showing that the wires do cause attenuation and diffraction of the transmitted light. The other detector is not important in this case because we are measuring the amount of diffracted light so he can compare it to fig 8c. and say here is the amount of light diffracted with no interference and here is the amount when interference is present. This is how he proves that interference is present.

Dear hugues,

As mentioned in my 12/26/04 @ 16:59 post in (Questions 1) page, you can see from the image plane data in this figure: http://www.physics.ohio-state.edu/~perry/p631/articles/afshar_Slide3.GIF (originally from my seminar at Harvard) that there is indeed a small leak to the "wrong" image region when one pinhole is open. But the situation for the case when both pinholes are open, is not the same as the case in which only one pinhole is open. Remember, you must first add the amplitudes and then square them for an observable. Most people forget this, and carelessly sum up the squared scattered amplitudes from both pinholes, when both are open, which INCORRECTLY leads to the conclusion that the WWI is reduced. If it is done correctly, the sum of the scattered amplitudes from both pinholes cancel out (because they are out of phase by Pi at the wires) and thus never lead to an observable downstream when we square the wavefunctions to get the flux density.

Incidentally, were you one of Sasha's postdocs at BU? Did you guys talk about this experiment, and if yes, what did Sasha think?

Regards.

Thank you for your answers. I will think more about it.
Yes, I was one of Sasha's postdocs at BU, but I left 6 months ago, and I have no idea what he thinks about that.
Bests

Hugues

Dear ALL

New preprint about this experiment:

Logical analysis of the Bohr Complementarity
Principle in Afshar’s experiment under the
NAFL interpretation

http://arxiv.org/PS_cache/quant-ph/pdf/0504/0504115.pdf

From the paper:

2.1 The Main Postulate of NAFL
If a proposition P is provable/refutable in a consistent NAFL theory
T, then P is true/false with respect to T (henceforth abbreviated as
‘true/false in T’); i.e., a model for T will assign P to be true/false.
If P is undecidable in a consistent NAFL theory T, then the Main
Postulate [5] provides the appropriate truth definition as follows: P
is true/false in T if and only if P is provable/refutable in an interpre-
tation T* of T. Here T* is an axiomatic NAFL theory that, like T,
temporarily resides in the human mind and acts as a ‘truth-maker’
for (a model of) T. The theorems of T* are precisely those propositions
that are assigned ‘true’ in the NAFL model of T, which, unlike
its classical counterpart, is not ‘pre-existing’ and is instantaneously
generated by T*. Note that for a given consistent theory T, T* could
vary in time according to the free will of the human mind that interprets
T; for example, T* could be T+P or T+¬P or just T itself at
different times for a given human mind, or in the context of quantum
mechanics, for a given observer. Further, T* could vary from
one observer to another at any given time; each observer determines
T* by his or her own free will. The essence of the Main Postulate
is that P is true/false in T if and only if it has been axiomatically
declared as true/false by virtue of its provability/refutability in T*.
In the absence of any such axiomatic declarations, i.e., if P is undecidable
in T* (e.g. take T*=T), then P is ‘neither true nor false’ in
T and Proposition 1 shows that consistency of T requires the laws of
the excluded middle and non-contradiction to fail in a non-classical
model for T in which P&¬P is the case

I have never seen such a basket full of horse apples in a single supposed scientific paper. This will be the title of the paper written in reply:

QMBS in a SSSP

Just a little humor in the AM! 8)

So what do you think about this paper?

Dear Quantum Mirror,
Thank you for inviting comments on my paper. The passage you have quoted has been published in the Int. J. Quant. Info.; see Ref. [4] of my paper. This paper is based on a new logic, NAFL, that was introduced to the physics community in the FQI04 conference noted in Ref. [4]. There were physicists, logicians, philosophers, mathematicians at that conferece. You need to understand what a logic is, before you attempt to judge this work. I suggest that you make the effort to do so. You may find it rewarding.
Regards,
R. S.

Dear Quantum Mirror,


I am not an expert in NAFL, so I cannot say what he is talking about. In a way, I'm glad I dont understand this. I dont think a reviewer will find it easy to decipher either. If only because of this difficulty to decipher, I do not think that the Afshar expeirment will be rejected by this manuscript.

Thanx again for keeping the blog updated

Peter Tanguay

Dear Peter Tanguay,
My paper accepts (or rather, takes for granted) Prof. Afshar's main experimental conclusions,, namely: (1) The interference pattern is present. (2) Which-way information (WWI) is also present. So it certainly does NOT reject the Afshar experiment; quite the opposite. But despite (1) and (2), Complementarity as I have defined it (and I think, as Bohr intended) is upheld.

The main part of the argument is that the presence of the interference pattern does not PROVE (in a logical sense) that the photon was `really' a wave, i.e., that it `really' exhibited self-interference. The NAFL interpretation of quantum superposition does not ascribe reality to the wave nature of the photon; rather, it only means that WWI was not available to the observer during the times that the superposition held. The interference pattern only indicates that a non-classical probability distribution applied to the photons, still treated as particles. In order to appreciate what quantum superposition means in NAFL, you need to understand the bare essentials of logic and the NAFL truth definition that Quantum Mirror posted (and ridiculed).

In a sense, I am arguing the opposite of Kastner, who would like the wave nature to be `real' and so rejects that WWI is present in the Afshar expt. In order for Complementarity to be violated in NAFL, one must *simultaneously* demonstrate that the superposed state AND the WWI hold, but this does not happen in the Afshar setup; the WWI only comes later, at time t_2 (see Fig. 1 of my paper) and applies retroactively, whereas the superposed state held prior to t_2. So the WWI does not conflict with the NAFL interpretation of the superposed state, either temporally or in meaning.

I can post a more detailed explanation if necessary. It is not all that difficult to follow what I am saying and I think the explanations I have given in my paper are quite clear. But, you need to set aside preconceived notions/prejudices and take an objective and patient look at my work.
Regards, RS

Dear R. Srinivasan

I think that logic has always been my guide in science and I gravitate toward Quantum Theory because it is the most illogical of all the investigations of science and I want to pull it toward a more logical framework. I think the biggest errors were in the early years of QT and the many years of teaching uncertainty, complementarity and many more aspects QT have caused many errors in logic. I must admit I have not deciphered all of the paper and will make a effort to do so. I do not think the answer to logic in QT will be accomplished by stretching the logic to fit the ideas of current thinking as NAFL seems to do, but to change the earlier errors to a more logical framework. Here is a preprint I like which would change the uncertainty principle and most of CI. I do not think it is complete but brings some logic to QT.

http://arxiv.org/PS_cache/quant-ph/pdf/0504/0504058.pdf

Dear Quantum Mirror,
Thank you for the link. You may well be right that completely new ideas (especially on the nature of light) are needed to bring all of quantum mechanics within a satisfactory logical framework. In fact I have made such a disclaimer in my paper. On the other hand, NAFL already radically departs from many accepted results in conventional mathematics/logic, and may well provide the logical framework for the revolutionary future theories in QM that you have in mind. For example, infinite sets cannot exist in consistent NAFL theories. So how does one justify real analysis in NAFL? My next paper will address this important issue; only then can we think of how to formulate consistent postulates for QM in NAFL. Alternatively, can we do without real numbers? It seems almost inconceivable at the moment, but you may be surpristed to know that at least one prominent quantum physicist (A. Zeilinger) thinks so. He made such an assertion at the FQI04 conference.
Regards, RS

Dear ALL

A fractal entropy dissemination state in complex quantum theory.

After reading much of the paper by R. Srinivasan, it occurred to me that QM as interpreted by NAFL will enter a state of entropy from which it is not possible to make any advances in this field. The confusion that is already inherent in QM combined with the obfuscation and confusion of NAFL means that each paper instead of adding to the knowledge actually adds to the disinformation and confusion.


My question for R. Srinivasan: The universe has been around for at least 12 billion years. The human mind a small fraction of that time. The purpose of Physics is to understand everything in that universe and how it is put together. How do you logically include the mind as a part of quantum physics?

Dear Quantum Mirror,
The obfuscation/confusion is present in interpretations such as, Cramer's Transactional Interpretation or Many-Worlds. If you are comfortable with "atemporal transactions" and with "confirmation waves" propagating backwards in time or with uncountably many parallel universes, then good luck to you. The NAFL interpretation explains some of the puzzling aspects of QM with unprecedented clarity. But it would be too much of an effort to explain it to you.
Regards, RS

[I an sending this message again as the previous one got truncated for some obscure reason]
Dear Quantum Mirror,
OK, let me try to give a very brief reply to your question. First of all, I claim that the NAFL formulation is a requirement of logical consistency. You should take a look at the proof of Proposition 1 of my paper (for which I have cited earlier references). Secondly, is it clear to you that all truths are pre-existing, independent of the human mind? This is certainly not clear to me. For example, without human beings is it meaningful to talk of the distinction between left/right or east/west, etc.? But leaving aside such deep issues, if you look at my paper carefully, you will see that I am actually supporting the existence of the particle state of the photon as a "reality" independent of the human mind. What depends on the human mind is the probability distribution that one computes for the photons. Thus for t_0

Dear Quantum Mirror,
So the "less than" sign truncates the post. Why? This is more mysterious than quantum mechanics itself. My apologies to Prof. Afshar.

What I was trying to express is the following. The probability distributions depend on the (non-)availability of WWI. If WWI is not available prior to time t_2, then one computes the quantum probability distribution and the interference pattern is seen. In the Afshar Expt., WWI becomes available after time t_2, but this does not "propagate backwards in time" and prevent the superposed state in NAFL. Instead, the WWI can be interpreted to confirm the "reality" of the particle nature of the photon which held all along. The main point is that one does not assign "reality" to the superposed state used to compute quantum probabilities in the NAFL interpretation; instead, the superposed state means that WWI was not available to the observer during those times. It is very important to understand the NAFL truth definition (the Main Postulate, Proposition 1 and its proof) as well as to understand the temporal nature of NAFL truth. These two features of NAFL enable us to make sense of the Afshar Expt. Classically, if WWI becomes available at time t_2, it would prevent the superposition from holding even at earlier times (and hence prevent the interference pattern from appearing), unlike the situation in NAFL.

Quantum Mirror is apparently objecting to the probability distributions depending on the
(non-)availability of WWI to the observer. But probability itself is a paradoxical notion that is observer-dependent even classically (e.g. "conditional" probabilities). So this is not all that surprising to me, though I have no explanation at this point of time on why such a dependency occurs.
Regards, RS

"The obfuscation/confusion is present in interpretations such as, Cramer's Transactional Interpretation or Many-Worlds. If you are comfortable with "atemporal transactions" and with "confirmation waves"

I would agree with that. I did not mean that all confusion was caused by NAFL. It already seems that you can interpret a experimental result one way and have 10 people see it 10 different ways. I would hate to see it get any worse. I am not at all comfortable with atemporal anything, but experimental results must be explained. Have you seen this preprint on CIEM?

http://arxiv.org/PS_cache/quant-ph/pdf/0503/0503201.pdf

I really like this paper and think it is the most logical I have seen.

" is it clear to you that all truths are pre-existing, independent of the human mind"

I would not say all truths, only the physical truths that built the universe. They did that without our help using energy and lots of time.

Dr. Afshar -- I am totally an amateur thinker in this realm. However, it has long been my thinking that as regards quantum mechanics and our knowledge of universal principles that there is not "matter" and "energy" as unique entities (or provinces). The idea that matter somehow "converts" to energy and vice versa is probably a product of our effort to understand phenomena. That both states are governed by one set of "rules" only reinforces the likelihood that we are, in fact, always dealing with one ultimate "essence." Further thinking suggests that the essence is energy. Recent revelations that so-called particulate energy has characteristics of string tends to support this type of imagery for all energy. When one considers all the known spectra of energy, the similarities of behavior must seem remarkable unless we begin to look at them as variants of the same fundamental essence. The conclusion I drew was that our measurement tools are quite crude compared to the exquisite nature of the energies we seek to analyze. Suppose energy, released from the gravitational (i.e. energy-bonded) confines, is represented by linked bi-polar modules (something like N-S or +/-) and because of this quantum-like unit polarity extends string-like in rays. Our measuring devices typically rely on intersecting and quantifying the intersected moment. So what we recognize - depending on technique - resembles particles or waves. But it could be neither, as your experiment seems to indicate. I'm not sure why I write you this, as you seem to have been considering something quite similar already. Diego Gonzalez

Dear Quantum Mirror,
I looked briefly at the paper
http://arxiv.org/PS_cache/quant-ph/pdf/0503/0503201.pdf
Here is what seems to be the Achilles Heel:

"The CIEM model of the photoelectric effect is of the nonlocal absorption of a photon by a localized atom. The photon prior to absorption may be spread over large regions of space"

In other words, the author seems to be saying that in, say, a beamsplitter, an incident photon splits and passes through both output paths, but is "nonlocally absorbed", at a detector in only one of the paths. The author can do a lot of fancy mathematics to justify this assertion, but it will not have too many takers. In the NAFL interpretation of the beamsplitter expt., the observer did not have WWI prior to the absorption/detection, so the superposed state holds for these times. The superposed state means precisely that the obsever did not have the path information. After the detection, the observer has WWI, and can retroactively assert that the photon passed through only one of the paths, as a particle.

NAFL does not deny that there are truths independent of the human mind. However, the *formal* truths exist only with respect to axiomatic theories and are those that are perceived by the human mind as axiomatic declarations, either directly or via a proof in an axiomatic theory. I claim that this formulation is a requirement of logical consistency, as I had indicated earlier. Truths outside of the primary formalism can be metamathematical (pertaining to semantics, or model theory) or metalogical (i.e., outside of even semantics of NAFL theories).
Regards, RS

Dear All

A new preprint with a very interesting experimental outcome.

"These outcomes (independently confirmed by crossing photon beam experiments in both the optical and the microwave range) apparently rule out the Copenhagen interpretation of the quantum wave, i.e. the probability wave, by admitting an interpretation in terms of the Einstein-de Broglie-Bohm hollow wave for photons. Moreover, this second experiment further supports the interpretation of the hollow wave as a deformation of the Minkowski spacetime geometry."

http://arxiv.org/ftp/physics/papers/0504/0504166.pdf

While digging for more information I found this paper entitled:

THE SHADOW OF LIGHT: LORENTZ INVARIANCE AND
COMPLEMENTARITY PRINCIPLE IN ANOMALOUS PHOTON
BEHAVIOUR

http://xxx.sf.nchc.gov.tw/ftp/physics/papers/0504/0504114.pdf

frpm this paper a mention of the afshar paper I had missed:
Therefore, both corpuscle and wave properties manifest themselves in the same photon system, at the same time, in the same experimental apparatus. Consequently, our experimental results seemingly invalidate Bohr’s principle of complementarity

Let us notice that recently Afshar carried out a double-slit experiment, that
apparently proves a failure of the complementarity principle [10]. He essentially showed that the coherent superposition state, corresponding to the interference pattern, persists
regardless of the fact that the which-way information (trajectory) is obtained in the same
experimental apparatus. Moreover, he states that evidence for coherent wavelike
behaviour is not a single-particle property, but an ensemble (multi-particle) property.
Although the results of ref. [10] do agree with ours, in denying the validity of the wavecourpuscle complementarity, let us stress that Afshar’s experiment is in a sense dual (or complementary) to ours. In fact, in a corpuscle behaviour (trajectory) was observed within a pure wave setting (double-slit interferometer); on the contrary, in our case a wave behaviour (interference) was observed within a pure corpuscular framework.

Dear prof. Afshar,

I have been able to study the mathematics of Fourier optics and I have clearly seen where your error is! You simply ignore the fact that converging lens action is just to convert the spherical frontwaves into plane frontwaves. Actually the image at the Fourier plane is nothing but INTERFERENCE PATTERN. Your error comes from improper comparison of fig.1 and fig.2 in your paper. Well it would be obvious that fig.2 is interference pattern if you have provided the intensity distribution of the higher order maxima surrounding the two Airy discs. The diference between fig.1 and fig.2 is that in the first case the Rayleigh criterion is not satisfied so you have only one central maximum, while in the fig.2. you have splitted with the use of the lens the central maximum into two maxima.

For reference use my paper:
http://philsci-archive.pitt.edu/archive/00002281/

p.s. Responce to your previous commentary: I have not been at all been interested in the Glen-Thompson prisms that separate the pairs of photons, as discussed in Kim et al. 1999. I have just said that the "which way" measurement on idler photon 2 is performed by a prism. So please check again the Kim et al. 1999 paper at ArXiv.org [quant-ph/9903047].

You may ask what is the difference between a prism and a converging lens. Well, the converging lens crosses the light beams coming from the two pinholes so there is interference, while the prism if properly positioned does not cross the light beams.

Well, if one is interested I recommend to check out my PhilSci paper.

Danko Georgiev

Danko Georgiev

Wow, you really worked hard on this paper.

"In contrast Afshar claims to have been able to determine both photon’s path and
momentum in the same experiment thus violating Heisenberg’s uncertainty relations and frankly admits that he is searching for a new physical theory of light."

There are several mistakes in this tiny sentence alone. (First error)It is which way and wave in the same experiment, not momentum. (second error) it is not HUP but complementarity he is violating. (third error) The idea that he is searching for a new theory of light is patently absurd and made up, as prof afshar has never mentioned such an idea.


"In the July 24, 2004 edition of New Scientist Afshar openly accused the fathers of Quantum
Mechanics to have developed fundamentally wrong theory and suggested that possibly there is no such thing as a photon:"

The New scientist magazine is not a scientific publication. (error 1) one of the first questions on this blog was about QM here is afshar answer:Quantum-Mechanical formalism is completely valid, and should be used to make the calculations for the the amplitudes, as well as the observables in any experiment.(error2) No such thing as a photon? have you gone mad? The photon is mentioned in the paper 19 times. How could he use the photon in the paper and say it does not exist? You are clearly a demented individual to work so hard on a paper with such idiocy involved.(error 3)

"Further, assuming that there is no such thing as a photon Afshar insisted that Einstein’s Nobel Prize for the discovery of the photoelectric effect should be taken back! It is amazing that Afshar takes back with an easy-hand Nobel Prizes:"

The lines you use to validate these outlandish statement are taken out of context and embellished by you.

That is just the tip of the iceberg. You make more errors than I thought humanly possible. The following references are not scientific papers and are as worthless as the entire paper.

Afshar, S.S. (2004). Waving Copenhagen Good-bye: Were the founders of Quantum Mechanics
wrong? Harvard University HEPL, 42 Oxford St., 3rd Fl. Conf. Rm., March 23.

Chown, M. (2004). Quantum Rebel. New Scientist, July 24, No.2457.
Cramer, J.G. (1984). Other Universes II. Alternate View Column AV-03, Analog Science Fiction &
Fact Magazine. http://www.npl.washington.edu/AV/altvw03.html
Cramer, J.G. (2004a). The Blind Men and the Quantum: Adding Vision to the Quantum World. 1st
Hal Clement Memorial Lecture, Boskone 41, Boston, MA, February 15.
http://faculty.washington.edu/jcramer/PowerPoint/Boskone_0402.ppt
Cramer, J.G. (2004b). A Farewell To Copenhagen? Analog - The Alternate View.
http://www.analogsf.com/0410/altview2.shtml
Cramer, J.G. (1998). The Quantum Eraser. Alternate View Column AV-90, Analog Science Fiction
& Fact Magazine. http://www.npl.washington.edu/AV/altvw90.html
39
Cramer, K. (2004). Shahriar S. Afshar: Quantum Rebel.
http://kathryncramer.typepad.com/kathryn_cramer/wblog/archives/000674.html
Dürr, S. & Rempe, G. (2000). Can wave-particle duality be based on the uncertainty relation? Max-
Planck-Institut für Quantenoptik, Progress Report 2001/2002.
http://www.mpq.mpg.de/qdynamics/publications/library/qdynamics02.pdf
Hartle, J.B. (1992). The Space-time Approach To Quantum Mechanics. http://arxiv.org/abs/grqc/
9210004
http://arxiv.org/abs/quant-ph/9903047
Larkin, K.G. & Oldfield, M. (1997a). Fourier Optics: Fraunhofer Diffraction and the 2D Fourier
Transform. http://oldsite.vislab.usyd.edu.au/CP3/Four6/node1.html
Larkin, K.G. & Oldfield, M. (1997b). Fourier Optics: Fraunhofer Diffraction – Exercises.
http://oldsite.vislab.usyd.edu.au/CP3/Four6/node1.html
Melles Griot Inc. (2005). Diffraction. http://www.mellesgriot.com/products/optics/fo_3_1.htm
Rhodes, R (2005). Commentary on “A Delayed Choice Quantum Eraser”. The Reality Program.
http://www.bottomlayer.com/bottom/kim-scully/kim-scully-web.htm
Scully, M.O. & Drühl, K. (1982). Quantum eraser: A proposed photon correlation experiment
concerning observation and ‘delayed choice’ in quantum mechanics. Phys. Rev. A 25: 2208-2213.

Dear Quantum Mirror,

you are very passionate in criticizing me! Well, I am really hard follower of Karl Popper, so I enjoy to be criticized - this will just "test" what I have done i.e. if my work is true it will survive, and if false will be destructed.

Well, you certainly claimed a lot of wrong things.

1. At least in the case of one qubit the complementarity IS manifestation of HUR.
2. If you measure wavelength [lambda] you measure momentum [p] and vice versa. The relation is:
[p]=h/[lambda]
3. What about the "idiotic things" it is not me who claims them but Afshar.

What I have done is to translate the Afshar's "pompous style" into CLEAR STYLE understandable for everybody.

When he says "welcher weg" this is nothing but claim that uncertainty about position [delta_x] is close to zero i.e. well defined, and when he says "interference" this is nothing but claim that he has measured momentum of the photon, because the interference fringes provide info about the wavelength.

My paper is crystally clear - and it should be even for those who have no idea of QM at all. You cannot have "wave-length" - note the root "wave" if you don't have uncertainty about position x. If x is certain then the "wave" is gone and there is no "wavelength". Considering that wavelength is linked to the momentum by the above relation, this also means that the momenum is not precisely defined.

My essay is clearly written, so enjoy reading it. If been able to carefully re-think each word used in the abstract, so there is nothing superficial in it.

And as an end - my so-called "translation" of Afshar, is based on mathematical equations, so it is very precise. Note: the equation p = h/lambda has only one constant and two variables linked through this constant, so it resembles really like "dictionary" -- "a" means "b" :-) I hope you understood this last joke!

Best,

Danko

A note on the references provided by me

First, Afshar's paper is just submitted and I doubt that it will ever be published in any good journal.

Second, since Afshar is promoting his work in the web, I am quoting his web postings i.e. I do not have the chance to quote published paper, because it may never be published :-)

Finally, I doubt that a real physicist will need my paper in order to see Afshar's error, because most professional physicists are far above my level in mathematics and physics.

So, my paper is aimed at those who will start learning QM in the future in order to show them the right sources to do that. And certainly The Optics Project at Department of Physics and Astronomy, Mississippi State University is a good source for begginers.

p.s. If the web courses for begginers quoted by me are for begginers, I am asking myself why Afshar [if he is experienced in the field] is not acquainted with them ?

What are you trying to do, Quantum Mirror? Trying to defend Afshar at any cost? It
is clear from your posts that you don't even conceive a simple possibility: Afshar is
wrong.

Despite anything you have read on the literature, the converging lens does not
provide which-way information when both pinholes are open. Please, define:

A := "photon passed through pinhole 1",

B := "photon detected at detector 2".

I challenge you to prove that P(B | A) = 0 from the general principles of quantum
theory. If this is not the case, there is no which-way determination. Please, you must
try to falsify the assertions of Afshar. After all, what are we discussing here? Science
or Ideology?

Dear Quantum Mirror,

You say: "No such thing as a photon? have you gone mad? The photon is mentioned in the paper 19 times. How could he use the photon in the paper and say it does not exist? You are clearly a demented individual to work so hard on a paper with such idiocy involved"

Well, possibly you have not read the New Scientist paper, or if you did [because obviously you have counted how many time the word "photon" is used] you have not understood Afshar's position at all. Really the paper is written by Marcus Chown, but indeed he quotes Afshar!

So everything is clear - Afshar says that Einstein's Nobel Prize should be taken because there is no such thing as photon. Re-read this text again and don't tell me that I accuse Afshar without reason.

Best,

Danko

Dear Danko Georgiev MD,

You have certainly outdone yourself this time! I am sure the copying and pasting of ill-understood concepts and graphics from different sites must have been time consuming, but sadly it shows your complete incompetence in the topic, and it is quite frankly disgraceful. You have certainly overstepped your personal boundaries by statements like: "We suppose that Cramer's error does not result from ignorance of mathematics but it is due to psychological factors..." I would suggest you have yourself checked for BPD (I'm sure you know what that is Dr.), as you certainly seem to project your own shortcomings unto others!

Just like your telediagnosis, the technical merit of your argument is nonexistent (again due to the fact that you have no idea what you are talking about!) In page 13 of your non-paper you say the lens converts the spherical wavefronts into plane waves. That is true if we use a 1f-1f system as shown in Fig. 10. But in my experiment the lens is placed well beyond 1f from the dual pinholes, and thus produces images in the image plane. Another sign of your lack of understanding of even the basics of the subject matter is the fact that you naively ASSUME that the image plane is the SAME as the focal plane; it certainly IS NOT! If the distance between the lens and the object is more than f (which is the case in my experiment), the image plane falls at a distance always grater than f from the focal plane (which is the Fourier plane if the light illuminating the object is collimated), unless the object itself is placed at infinity, in which case the focal plane and the image plane become the same (due to the fact that light from an infinitely far source is a plane wave)...

This Blog is not an educational site (as outlined at the top of page), but since you seem to be fond of using internet resources, I would suggest you play with the applets in this link: http://webphysics.davidson.edu/applets/Optics/intro.html to get the hang of how a lens works in the geometric limit, and where the focal and image planes are.

To wit, the images in the IMAGE plane (read my paper carefully) provide highly reliable which-way information. [I can’t believe I wasted 15 precious minutes of my life on this nonsense!!!!]

P.S. I am normally not too critical, but you have certainly earned this frank counsel: Please stick to your own profession. There is nothing more embarrassing than a non-specialist making irrelevant remarks in a field well outside his domain.

Dear Danko Georgiev MD,

"Afshar says that Einstein's Nobel Prize should be taken because there is no such thing as photon"

NO! I said, "In order to declare Einstein the winner of the Bohr-Einstein debate, we should take back his Nobel Prize." That is because Einstein's idea of a bullet-like photon with straight line trajectory is completely false, and if he kept using the wave model he could have thought of my experiment. That statement is a popularized dramatization aimed at the lay audience of the NS magazine. Obviously, Einstein deserved his Nobel prize; it is just that he should have gotten it for his remarkable Relativity theories rather than his explanation for the photoelectric effect (which has been explained semicalssically by Willis Lamb).

As for "there is no photon" quote, I have expressed my "gut" feeling that ultimately we will find that photons do not exist, but I have made it clear that is my personal opinion, and nothing more. The aim of the experiment has been to rule out Complementarity (which it has successfully achieved), not to rule out photons. Please read the whole article...

Dear all,

If you are local come join us in celebration of Einstein's Centennial. For more info check out this link:
Afshar Experiment: Einstein's Rebellion Lives On At Rowan!
Regards.

Dear prof. Afshar,

You say: "Einstein's idea of a bullet-like photon with straight line trajectory is completely false". NO! whether the photon will move in a straight line or not depends on Principle of Complementarity. In the case of a single qubit this may be seen in HUR. For multiple qubit entangled state the explanation invokes entanglement between the multiple qubit system and the measuring intrument(s) [in general].

Well, I agree that the New scientist paper is too "dramatically written", but even if we ignore it, the problem is still there -

whether there is grid or not, the lens is not measuring the "which way" info.

In order to have "Fourier image" you need INTERFERENCE of information from every elemental aperture of the global aperture pattern [two-slit, three-slit, etc.]. Also I am curious that you have paid little attention to the popularization of the HOLOGRAPHY, and explanation of holograms as Fourier transformed images.

Danko

Dear Danko Georgiev,

EVRY image is produced by the self-interference of the diverging parts of the same wavefunction originating from a point source on the object. In my experiment we have two such sources. i.e. the two pinholes. But in the image plane, the two separated wavefuntions do not overlap, and thus cannot produce a spatial interference pattern, as evidenced by the two individual spots. Do you now understand the difference between the image plane and the focal plane? BTW/ contraty to your assertion, my images beat the Raleigh crtierion handsomely (that is if you really understand the criterion)!

"whether there is grid or not, the lens is not measuring the "which way" info. "

Then you are saying Heisenberg's Microscope proof of the uncertainty principle is wrong! Good luck proving that...

Danko Georgiev

Karl Popper, you don't even belong on the same planet as he does. He is the father of the scientific positivism and you are the Weekly World News scavenger.

"Well, possibly you have not read the New Scientist paper"

The New Scientist magazine is not a scientific paper. If one could use popular magazine and web site articles to argue science, anyone could destroy relativity, evolution, Bohr, quantum mechanics or any theory. There would be no science.

You must admit that you collected all the garbage you could find and twisted it to the worst possible conclusion in anger over the reply you received from afshar. You could not possibly understand QM or the scientific method to make such idiotic conclusions based on such unreliable source material. I am certainly glad you are not my medical doctor. I would hide all the Good Housekeeping and Ladies Home Journal medical articles in your waiting room.

Dear Prof. Afshar,
In your recent posts to Danko Georgiev, you make the following assertions:

(1) "To wit, the images in the IMAGE plane (read my paper carefully) provide highly reliable which-way information".
(2) "That is because Einstein's idea of a bullet-like photon with straight line trajectory is completely false, and if he kept using the wave model he could have thought of my experiment."

From (2), it would appear that you would conclude the wave nature of the photon from the existence of the interference pattern in your experiment; i.e., you would conclude that the photon "really" passed through both slits, as a wave. How do you reconcile this assertion with (1), which would indicate that you believe the which-way information to be "reliable", which in turn means that you believe that the photon "really" passed through only one slit? Or are you assuming something like the CIEM model [quant-ph/0503201] of Kaloyerou to reconcile the which-way information with a wave model? Or are you viewing this as a paradox which cannot be explained using existing theories?
Regards, RS

Dear R. Srinivasan,

"Or are you viewing this as a paradox which cannot be explained using existing theories?"

I would LEAN towards this option, but that is purely a personal preference and nothing more.

Regards.

Dear prof afshar
I really am one to jump on a bandwagon for a while if I find something that fits, but that is just my nature. :) I can jump off very quickly also as I am quite flexible. I am on this bandwagon now:

http://arxiv.org/ftp/physics/papers/0504/0504166.pdf

In this paper when you have time to read it, the author explains interference as deformation of the Minkowski space-time geometry by breakdown of local Lorentz invariance. This would be a incredible breakthrough which could unite relativity with quantum theory. I was wondering if you had read this and your thoughts on it. It is all based on experimental results.

Dear QM,

It looks very intereting. I'll read up on it next week, and thanks for the heads up!

Regards.

Dear prof. Afshar,

I will "close my eyes" for the fact you have personal attitude to my personality, not to my critique. Now straight to the topic:

You simply do not understand what the Fourier transform is, so I will clarify the issue using the exact values [data] from your experimental setup. I have been able to use the online calculator of the Rayleigh criterion at:

http://webphysics.davidson.edu/mjb/SESAPS2000/rayleigh3.html

in order to verify that your results are not manipulated. What is good is that you really have provided true results and I express my regards for providing all details about your setup in the IRIMS paper.

So now I will show you that I am very well acquainted with the action of the converging lens and that I do make distinction about the focal and image planes. However I didnot consider that the details of so great importance for my PhilSci paper - they are obvious.

Let me first list some relevant info from your setup:
photon wavelength - lambda = 650 nm;
distance between pinholes - d = 2 mm;
pinhole (aperture) diameter - a = 0.25 mm.

1. Using the Rayleigh criterion you may easily see that the Airy disc of each pinhole "grows" along the optical axis. At distance up to ~0.5 meters the two Airy discs have not yet significantly interfered with light coming from the other pinhole.

2. You first put screen sigma_1 at distance L from the double-pinhole L = 4 m. So at this distance the double-slit pattern is clearly seen. Also at this place the image is essentially Fraunhofer diffraction image - i.e. the wavefronts can be approximated as plane ones - the usual criterion is d

2. You first put screen sigma_1 at distance L from the double-pinhole L = 4 m. So at this distance the double-slit pattern is clearly seen. Also at this place the image is essentially Fraunhofer diffraction image - i.e. the wavefronts can be approximated as plane ones - the usual criterion is d

Dear prof. Afshar,

I will "close my eyes" for the fact you have personal attitude to my personality, not to my critique. Now straight to the topic:

You simply do not understand what the Fourier transform is, so I will clarify the issue using the exact values [data] from your experimental setup. I have been able to use the online calculator of the Rayleigh criterion at:

http://webphysics.davidson.edu/mjb/SESAPS2000/rayleigh3.html

in order to verify that your results are not manipulated. What is good is that you really have provided true results and I express my regards for providing all details about your setup in the IRIMS paper.

So now I will show you that I am very well acquainted with the action of the converging lens and that I do make distinction about the focal and image planes. However I didnot consider that the details of so great importance for my PhilSci paper - they are obvious.

Let me first list some relevant info from your setup:
photon wavelength - lambda = 650 nm;
distance between pinholes - d = 2 mm;
pinhole (aperture) diameter - a = 0.25 mm.

1. Using the Rayleigh criterion you may easily see that the Airy disc of each pinhole "grows" along the optical axis. At distance up to ~0.5 meters the two Airy discs have not yet significantly interfered with light coming from the other pinhole.

2. You first put screen sigma_1 at distance L from the double-pinhole L = 4 m. So at this distance the double-slit pattern is clearly seen. Also at this place the image is essentially Fraunhofer diffraction image - i.e. the wavefronts can be approximated as plane ones - the usual criterion is d

Dear prof. Afshar,

I will "close my eyes" for the fact you have personal attitude to my personality, not to my critique. Now straight to the topic:

You simply do not understand what the Fourier transform is, so I will clarify the issue using the exact values [data] from your experimental setup. I have been able to use the online calculator of the Rayleigh criterion at:

http://webphysics.davidson.edu/mjb/SESAPS2000/rayleigh3.html

in order to verify that your results are not manipulated. What is good is that you really have provided true results and I express my regards for providing all details about your setup in the IRIMS paper.

So now I will show you that I am very well acquainted with the action of the converging lens and that I do make distinction about the focal and image planes. However I didnot consider that the details of so great importance for my PhilSci paper - they are obvious.

Let me first list some relevant info from your setup:
photon wavelength - lambda = 650 nm;
distance between pinholes - d = 2 mm;
pinhole (aperture) diameter - a = 0.25 mm.

1. Using the Rayleigh criterion you may easily see that the Airy disc of each pinhole "grows" along the optical axis. At distance up to ~0.5 meters the two Airy discs have not yet significantly interfered with light coming from the other pinhole.

2. You first put screen sigma_1 at distance L from the double-pinhole L = 4 m. So at this distance the double-slit pattern is clearly seen. Also at this place the image is essentially Fraunhofer diffraction image - i.e. the wavefronts can be approximated as plane ones - the usual criterion is d

Dear all,

sorry for this unsuccessful "pasting" of my Wikipedia response. Just check out the full version at:

http://en.wikipedia.org/wiki/Talk:Afshar_experiment

There is step-by-step analysis of the whole setup using data from the IRIMS pre-print.

Regards,

Danko

Dear R. Srinivasan,

Your remark is valid if you first say that there is [1]interference pattern and then you prove [2] that there is "which way" info. Going from 1 to 2 is ridiculous!

While Afshar first points out [2] then he goes to [1]. Now "as if" the situation implies paradox, because [2] is the "true" assumption from where you have started. Well, the problem is that [2] is false.

Danko

To Prof. Afshar:

This in line with Srinivasan thought. Forget Complementarity for a moment. It seems
that your experiment cannot be explained by the standard quantum theory. If you
believe that your setup provides which-way information, in your experiment you
know for each photon the slit through which it passed. In this case the quantum
recipe is to sum the probabilities and not the amplitudes for each alternative. In this
way there could be no interference, and your wires should be absorbing some of the
photons. Please, if you forget that private philosophy of Bohr called
Complementarity which was never really used by any working physicist, how do you
apply the standard quantum formalism to describe your experimental result:
which-way + interference?

After all, the quantum recipe is "add the amplitudes for each alternative when you
don't have any way to know that a single alternative happened at a time, otherwise
add the probabilities for each alternative". Since in your experiment you know
which-way each photon went, then you know that a single alternative happened before
each detection. So, add the probabilities, forget interference and standard quantum
theory can't explain your result of zero absorption at the wires.

Could you give me some light ;-) on that?

Regards.

Danko Georgiev

The Rayleigh criterion is a formula for figuring the resolving power of telescopes or lens systems. The formula is to figure how close two light sources can be together and the size of the lens needed to resolve detail. The minima and maxima in a pinhole are the brighter and darker circular lines caused by diffraction. This is not the same as the minima/ maxima of two slit or two pinhole interference pattern.The Rayleigh criteria is not a criteria for double slit interference. In fact has nothing to do with spatial relations of interference. You should really have an expert in quantum mechanics and physical/experimental optics look at your work before you post it all over the web. You are quick to study and make judgments but the devil is in the details.