NetNews Usenet Archive 1992 #18/NN_1992_18.iso/spool/sci/physics/12884

Text File | 1992-08-14 | 3.8 KB | 88 lines

Newsgroups: sci.physics
Path: sparky!uunet!haven.umd.edu!darwin.sura.net!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!pacbell.com!well!sarfatti
From: [e-mail] (Jack Sarfatti)
Subject: The End of Physics?
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: Whole Earth 'Lectronic Link
Date: Sat, 15 Aug 1992 02:17:05 GMT
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From [e-mail] Fri Aug 14 17:22:57 1992
Date: Fri, 14 Aug 92 17:22:04 PDT
From: [e-mail] (Aephraim M. Steinberg)
To: [e-mail]
Subject: Re:  asymmetric beam recombiner - can you make one?

You don't mind violating T-invariance, okay, there's certainly a
precedent.  Do you believe in energy conservation at all firmly,
on the other hand?  (You seemed to take people's concerns about unitarity
seriously, except for the von Neumann projection of course, which implies
to me that you do.)

Ou&Mandel's paper on this uses that, rather than time-reversal arguments,
and I bet the same is true of Born&Wolf. Cohen-Tannoudji et al show
it explicitly for the Schrodinger equation when they treat scattering,
using no supplementary assumptions.  (Except, of course, symmetry.)

I don't think the asymmetry will help you because one beam will experience
r1 but the beam coming from the other side will experience r2, and in
general, the fact that (r1+r2)-(t1+t2) = pi suffices in these
interferometry schemes to give the same final results as a symmetric beam
splitter.

Anyway, with my original example, forget time reversal invariance,
and just think energy conservation.  We already know that |t|^2+|r|^2 = 1
for a lossless splitter, and you saw that that would come back out
port I1 if you sent t* and r* in the other side; thus, if t*r+r*t were
nonzero, the beam splitter would somehow be creating energy.

aephraim

Sarfatti's response:
m [e-mail]
Subject: energy conservation
Yes, I agree that if it violates energy conservation it's wrong. However,
I think I can show that it does not. If you can find me your notes, the
Mandel and Cohen papers and fax them that would help. My fax number is
415 397 0250 it's same as my well modem no.

I think I can show that unitarity is a sufficient condition for
conservation of locally observable probabilities of detectors (hence also
energy conservation) but that it is not a necessary condition if cosb is
not equal to zero. But first I would like to see the info you mentioned.

P.S. Also for asymmetric beam recombiner, the fact that AVERAGE shift is
pi/2 does not matter since the light is only incident on one of the two
faces of the recombiner in the actual device.

I thave to think about what you say about creating energy - it could mean,
for example, tapping of zero point energy of quantum vacuum fluctuations -
cohering the fluctuations. I mean inducing a vacuum first order phase
transition like in the big bang.

In summary if we can achieve cosb not equal to zero then it appears to
imply:
1) precognition - indeed basic mechanism for consciousness
2) defeat of classical chaos limits of predictability of future events - we
would simply access information from the future rather than try to predict
it on basis of past Cauchy data.
3) parity violation of mirror symmetry - the mechanism for beta
radioactivity
4) violation of time reversal symmetry explaining the arrow of time's flow
from past to future
5) tapping of limitless quantum zero point vacuum fluctuation energy as in
mechanism of big bang creation of universe. If this could be harnessed it
might mean practical Star Ship propulsion for space-ships that might
locally generate there own closed timelike world lines to travel back in
time.

So it is very important we really study this. Keep up the good work!

Note for historical record: this "PS" not in original message to aephraim -
must send it later.