Talk:Afshar experiment/Archive 3

message: I want to add a short scientific comment concerning Afshar's work :
Afshar not only claimed that he can circumvent Bohr’s complementarity but that he can effectively determine the path followed by the particle. Afshar, following  here a assumption originally enounced by Bohr , Heisenberg and Wheeler, accepted that even with the two pinholes open a photon trajectory (if trajectory there is) will necessarily connect a pinhole to its optical image as it is if the other pinhole would be closed.  However, as  is was realized by numerous physicists as de Broglie, Bohm, Bell and Scully,  this is a free  metaphysical assumption   which depends of our model of reality and  which can not in general be experimentally tested [read for example “ Surrealistic Bohm trajectories”, Englert et al  in  Z. Naturforsch. Vol  47a , p 1175.]. 
Effectively nothing in the Afshar’s experiment forbids a photon coming from one pinhole to go in the ‘wrong’ detector for the second pinhole (this is the case for example in the Bohm’s theory).  Looking  the image of a  pinhole recorded in a statistical way by a myriad  of photon will not say us from which pinhole an individual  photon  come from but just how many photons crossed this pinhole (in reality it is even more terrible since quantum mechanics only tell us what will happen if we observe the photon). In counterpart of course we can not see the fringes and the complementarity principle of Bohr will be, as in every quantum experiment, naturally respected.
Since I am not a defender of Bohm' view I will not go further in this direction but you see that th concept of trajectory is ambiguous for a photon. 
--Drezet
Dear Aurelien,
I am glad that you start to see what I am saying - there is no which way information in the two pinhole case. The fact that there is lens changes nothing. If all those people including Wheeler et al. have ever claimed that the lens image contains the which way info at the image plane, then i will have to add them in the black list of the people who had done severe error.
By the way - as I know, Wheeler determines the which way with 2 telescopes = 2 lenses, not a single lens, and the 2 lenses do not cross the light beams. Do you see the difference?
Well, by for now, I will be back soon. Contact me by e-mail for further discussion.
Best,
Danko Georgiev, MD
Dear Danko just to tell you that I desagree Afshar's experiment is unlike the Schrodinger cat completely dead and it is useless to try  a reanimation : you are not Frankenstein 
--Drezet
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I noticed the "neutrality disputed" tag on the main Afshar page
and wondered if I should remove my entry, "Kastner's Interpretation",
on that page. If it is desired that I do this, please let me know,
and I'll be happy to do so. May I still list a reference to my
paper somewhere on the main Afshar page? 
Thanks,
R. Kastner
: The POV banner has nothing to do with your entry.  I put the POV banner up about a month ago, but the page now seems a little more balanced (although still could use some trimming in the pro/con section). Whatever happens to that section, my guess is that your reference (as well as Motl's and Unruh's) should probably remain, but of course, this being Wikipedia, who knows?--CSTAR 23:33, 17 Jun 2005 (UTC)
replies: text: Dear Dr. Kastner, I have no qualms about moving your entry, as well as my response to it, to this discussion page until we work out our differnces through e-mail and my weblog. But since I have been accused of being biased in the past, I cannot do it. Perhaps you and CSTAR could sort that out? Best regards.--Prof. Afshar 11:41, 18 Jun 2005 (UTC)
thread_title:  Interference of crossed beams (bis repetita) 

message: I like the new page : this is much more neutral and objectif.
NB: I changed the part concerning complementarity (using a part of an article I am currently writing ) if somebody disagree we can discuss.
--Drezet 22 june
Dear Drezet,
your entry concerning complementarity is ridiculous. You speak about metaphysics, so possibly you are "good metaphysicist" not good physicist. Physics uses strict mathematics and you use words that can be interpreted as one wants.
I have added the mathematical formulation of complementarity and I also write and develop my paper on complementarity. The text in my entry is from a lecture of Bob Eisenstein, professor in physics. I will add in my paper how the different calculations of probability (i) add then square, or (ii) square then add produce "interference" or "clumping" patterns. 
I am curious to know why you don't like mathematics? And also I don't understand your way of doing science - my advice is read Popper for the "demarcation criterion".
Best,
Danko
:: Danko.  Complementrity does have a mathematical definition in terms of consistent histories.  See p 170 of Omnes book or read some of Griffiths' papers.--CSTAR 20:33, 22 Jun 2005 (UTC)
thread_title:  Actual deletion