From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Newsgroups: sci.physics
Subject: Decisive Physics Test for Existence of ESP & God?
Date: 14 Aug 92 22:30:11 GMT
Organization: Whole Earth 'Lectronic Link


Physicists develop experimental test for the existence of ESP & God?

Message  3:
From aephraim@physics.Berkeley.EDU Fri Aug 14 12:54:17 1992
Date: Fri, 14 Aug 92 12:53:24 PDT
From: aephraim@physics.Berkeley.EDU (Aephraim M. Steinberg)
To: sarfatti@well.sf.ca.us
Subject: Re:  cosb = 0 contradicts Fresnel eqs?

Born & Wolf treats it, Cohen-Tannoudji does it for general Schrodinger
barriers, and Ou&Mandel had a paper on it a few years back.

As for the Fresnel equations, think of the simplest beam-splitter,
a thin sheet of glass which reflects 4% at each surface (we'll half-
justifiably ignore multiple reflections for now).

The amplitude for transmission is just exp(ikd) to lowest order, where
k is the wavevector and d is the thickness.

The amplitude for reflection off the front surface is +0.2, no pi phase
shift.The amplitude for reflection off the back surface is 0.2exp(2ikd),
where there is the pi phase shift you noted, but there are two
path lengths of d.  If you add the two phasors, you can see that the
phase of the resultant is the average of the two inital phases (2kd and
pi),that is, kd+pi/2, that is, phi(r)=pi/2 + phi(t) as claimed.

If you do it carefully for the infinite sum, you also get the right
answer,of course, that's just a plausibility argument in response to
your question about the Fresnel relations.

The general argument is easiest by time-reversal symmetry.

Suppose our input ports are I1 and I2, going into outputs O1 and O2.
If the amplitude incident on I1 is 1 and on I2 is 0, t comes out in O1
and r comes out in O2.

Let us now time-reverse this, assuming a symmetric beam-splitter (so r
and t are the same from either side).Now t* comes in O1 and r* comes in
O2, so t*t+r*r comes out I1 and t*r + r*t comes out I2. But we know
nothing originally went into I2, so t*r + r*t = 2Re (t*r) = 0.That is,
if we write t*r as |t||r|exp(iphi(r)-iphi(t)),cos(phi(r)-phi(t))=0, so
the phases differ by plus or minus 90 degrees.

There are other ways of showing this. If it's lossless but not
symmetric, then the AVERAGE of the two different reflection phase shifts
still differs from the transmission phase shift by 90 degrees.

If it's lossy, you can put an upper bound on that cosine, you can derive
it yourself or I can look for my old notes if you're curious.
I don't think it's reasonable to think that the losses would HELP you in
your scheme, though.(I admit I don't immediately understand how to
demonstrate this latter
guess though.)

Hope this is clear,
aephraim.


Sarfatti response: Yes Aephraim your exposition is clear.

OK I agree that for a symmetric beam splitter of the off-the-shelf
variety to lowest order that the effective reflection phase shift is
pi/2 and that, therefore, my faster-than-light communication gedanken
device will not work within those approximations because cosb = 0.

By the way, a minor correction that does not alter your conclusions, the
external reflection from air to glass at front face has pi shift and the
internal reflection from glass to air at back face has zero phase shift
for TE wave below critical angle. Oh yes, you are right for TM wave.



This is real progress. Thank you.

But we must leave no stone unturned since a potentially astonishing
physical discovery may be here if we can find a way to beat the
cosb = 0 barrier!

Your general argument from time reversal symmetry is important but all
it means is that if we can get cosb not equal to zero then causality
violation also breaks time reversal symmetry. I have already indicated
that causality violation here violates parity so why not also violate
time reversal symmetry and have a new microscopic mechanism for the
arrow of time?

So returning to the first part of your brilliant exposition.

We would need to introduce micro-inhomogeneities into the glass of the
beam splitter in such a way as to destroy the equality between the two
optical paths for the photon when in travels from front face to back
face on the one hand and from back face to front face on the other hand.

Thus, I am asking if we cannot be clever enough to invent a new kind of
optical beam recombiner so that the front to back face path is kd and
the back to front face path is kd + theta because of a tiny optical
impurity properly positioned for narrow enough beam widths. This would
be an optical analog to the doping in a transistor. If we can do that
then your argument becomes kd optical path for transmisson, 2kd +
theta(impurity) for internal reflection (TE case) and pi for external
reflection. So the average is shifted by the asymmetrical optical doping
to kd + pi/2 + theta/2. Subtract off the transmission shift gives b =
pi/2 + theta/2 where theta/2 is under our control.

If we can do this then we can violate causality, violate parity and
violate time reversal symmetry right where you are in Ray Chiao's lab at
UCB - and collect a Nobel Prize! (or two or three!)

It will be quite amazing if there really is a cosmic conspiracy to
prevent causality violation even though Kip Thorne et-al showed that you
can do it consistently for closed time-like worldlines and it would make
the origin of universe easier to understand as created by intelligent
design. If you can prove that such an asymmetric beam recombiner cannot
be built in principle then you have also made a very strong case against
the reality of psychic phenomena and the existence of an intelligent
creator of the universe.