From: scerir (scerir@libero.it)
Date: Sat May 11 2002 - 12:08:56 MDT
John K Clark:
> scerir wrote:
>
> > > Photon(s) 1 just passes through a double slit D, that's all.
>
> Photon 1 produces a dot (not a smudge, a dot) when it hits its screen, one
> photon never, EVER, produces an interference pattern. If you fire a lot of
> photons through the double slit then the dots will form a interference
> pattern, but one photon just makes a dot. Always.You can't know exactly
> where the dot will form but you can point to places it probably will form
> and places where it probably will not. The probability distribution is in
> the shape of a interference pattern, but when a photon actually hits a
> screen it always produces a sharp dot.
Yes, of course. I wrote: photon(s).
> Photon 2 like all photons will produce a sharp dot when it hits the
> screen,
> if you send more photons in this way the new ones will cluster around the
> first, but because photon 2 passed through no double slit there will be no
> interference pattern.
'Contra factum non valet argumentum'. Unfortunately the experiment (done)
shows that QM is weird. (But if we think in terms of a "bi-photon", and not
in terms of *two* photons, QM is, perhaps, less weird).
> > If you remove the D from the first beam, the interference
> > pattern on S vanishes.
>
> You will have no interference pattern from the second photon whatever you
> do to the first photon.
T.B. Pittman, Y.H. Shih, D.V. Strekalov, A.V. Sergienko
Phys. Rev., A, 52, R3429, (1995)
D.V. Strekalov, A.V. Sergienko, D.N. Klyshko, Y.H. Shih
Phys. Rev. Letters, 74, 3600, (1995)
Y.H. Shih, A.V. Sergienko, T.B. Pittman, D.V. Strekalov,
D.N. Klyshko, "Two-Photon 'Ghost' Image and Interference-
-Diffraction", in "Experimental Metaphysics - Quantum
Mechanical Studies for Abner Shimony", Volume one,
eds. R.S. Cohen, M. Horne, J. Stachel, pages 199-211,
Kluwer Academic Publ., (1997)
Also Leonard Mandel performed similar experiments, in Rochester
Univ., but I have no references.
[But I'm not saying here that, actually, we can use these weird
effects for FTL messages. I'm not sure that there is
a FTL effect here]
s.
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