[ExI] simulation

scerir scerir at libero.it
Tue Dec 18 07:28:26 UTC 2007

Gary Miller:
> But I admit the references which say this is impossible still seem to
> outnumber the ones which claim it is possible by about five to one.  But
> the other hand the papers which claim superluminal data transfer is
> are more recent. [...]
> http://casimirinstitute.net/coherence/Jensen.pdf

That one has been discussed here some time ago.
Cramer is now performing his experiment, similar
to Jensen's experiment.

Two-photon interference and one-photon interference
are obviously different phenomena. In the first case
we need a coincidence detection unit of some sort
(two clocks at least). In the second we do not need
any coincidence device.

It seems to me that these position/momentum correlated
photons 'signaling' machines are based on a sort of ...
fusion ... of the one-photon and the two-photon interference
phenomena. You perform a specific measurement on the idler
photons and, at a distance, *without checking the coincidences*,
you imagine that an interference pattern will appear,
or disappear, at a distance, at the signal wing.

Now it is known, since long time, there is an 'luciferine'
complementarity principle between the one-photon
and the two-photon interference. In the sense that
the more you can see the first interference, the less
you can see the second interference, and viceversa.

See, i.e., these papers:

M.A.Horne, A.Shimony, A.Zeilinger, 'Two-Particle Interferometry',
Phys.Rev.Lett. 62, 2209 (1989).
M.A.Horne, A.Shimony, A.Zeilinger,
'Two-Particle Interferometry', Nature, 347, 429 (1990).
D.M. Greenberger, M.A. Horne and A. Zeilinger,
'Multiparticle Interferometry and the Superposition Principle',
Physics Today 46 8, (1993).

and these specific experiments ...

Since the complementarity principles, in general,
presuppose a 'smooth' transition from the visibility
of a phenomenon to the visibility of the other,
here we can also expect a smooth transition
from the visibility of a single-photon interference
to the visibility of a two-photon interference,
and viceversa.

If there is an intermediate situation in which both
interferences are (badly) visible, and if - in this
intermediate and desperate situation - is still possible
to imagine 'signaling' experiments is difficult to say.
(I think we'll see that soon, since Cramer is playing
with his lasers now).

"Pronouncements of experts to the effect 
that something cannot be done have
always annoyed me."
- Leo Szilard

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