NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/sci/physics/21844

Internet Message Format | 1992-12-29 | 4.5 KB

Xref: sparky sci.physics:21844 alt.sci.physics.new-theories:2641
Path: sparky!uunet!mtnmath!paul
From: [e-mail] (Paul Budnik)
Newsgroups: sci.physics,alt.sci.physics.new-theories
Subject: Re: Aspect's experiment
Message-ID: <[e-mail]>
Date: 29 Dec 92 17:43:21 GMT
References: <[e-mail]>
Followup-To: sci.physics
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070
Lines: 81

In article <[e-mail]>, [e-mail] (Jack Sarfatti) writes:
>[...] Furthermore, Aspect's acoustically driven switching
> time for the polarizer orientations was short compared to flight time by a
> factor of order 10 as I recall - so the interval between detections of any
> two photons in the same pair is definitely spacelike. And I don't think
> it's clear to anyone but you if your "critical delay" is the same as
> Aspect's switching time.

The critical interval is not that between detecting two photons in the
same pair. The critical intervals are those between when the polarizers
change and this has an observable effect. These are not Aspect's switching
time. They are the intervals that must be measured to prove Bell's
inequality is violated.

> [...]
> No Paul - your above paragraph is totally garbled and confused! I mean
> specifically your remark:
>
> " these two events, the change in polarizer angles and the resulting change
> in joint detections
> have a space-like separation."
>
> Those are not the "two events" that must have a spacelike separation in
> order "to prove Bell's inequality is violated" - what you talk about as
> "events" are not "events" in the sense of special relativity. An event is a
> point (i.e. a small local region) in flat spacetime. Your so-called events
> are not localized. When you write "the change in polarizer angles" you are
> refering to the nonlocal relationship between the far-apart polarizers one
> for each photon in the backto back pair - unless you mean the change in
> orientation of one polarizer in a short time - that would be an event. But
> then your other event which is to be spacelike separated from this one is
> "the resulting change in joint detections" - that's no event - that's a
> delocalized prcess you have to compare data from both ends do a lot of
> computing etc.

Here you have a valid point. There are four events. Two polarizers
both of which must be changing their angle and two detections. Two pairs
of these events must be space-like separated to prove Bell's inequality
is violated. The change in each polarizer angle must be space-like separated
from detections at the more distant detector.

    |-------/-----------------[]----------------------/-----------|
Detector  Polarizer       Photon source            Polarizer   Detector
    A        A                                        B           B

The entire experiment is done in an inertial frame of reference so we
can speak of simultaneous events in that frame. The changes is polarizer
A must be space-like separated from detections at B and similarly the
changes in polarizer B must be space-like separated from detections at A.
You change both polarizers simultaneously and observe the delay between
when this change happens and it affects the probability of joint detections.

>[...]
> So Paul you seem to be insinuating that Leggett is attacking Aspect as an
> incompetent experimental physicist who has conned us all!

    Neither myself nor either of the authors cited are suggesting that
Aspect is incompetent. His analysis of this experiment was not complete. He left
out an important possibility. All scientists make mistakes at this level
and it is not a sign of incompetence, only a sign of the difficulty in
doing things correctly. That is why the details of important experiments
must be published and reviewed by a wide audience.

>[...]
> OK Paul, if you send me copies of the papers by Franson and Leggett I will
> read them objectively but they seem cranky- but maybe I'm wrong. But
> whatever it is you are trying to say you are still not saying it clearly.
>[...]

    I am not going to copy and mail the papers to you. They are readily
available at any good physics library. You generally do not need to have
lending privileges at a university library to look at and copy documents in
the library.

    I have been posting these results for three years and you are the
first person to seriously argue that they are technically incorrect.
Some people have doubted them, but did not seem willing to check out
the original papers. No one else has posted a `refutation' of these
arguments.

Paul Budnik