From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.skeptic
Subject: Re: Can quantum terminology be flakeproofed?
Date: 13 Oct 92 01:23:33 GMT
Article-I.D.: husc8.mcirvin.718939413

aa387@cleveland.Freenet.Edu (Jim Kutz) writes:

>You're  quite  correct  that  the  misinterpretation  of the word
>"observe" is what's causing the  problem. What I'm saying is that
>maybe  there's an  alternative (clearer)  way to  make statements
>about quantum uncertainty, without referring to an "observer" ?

Part of the problem is that physicists are by no means of one
voice about what really happens when an apparatus measures something.
This is the subject of all the disputes about the interpretation
of quantum mechanics over on sci.physics and in the literature.
The field is broadly divided (*very* roughly speaking) into
people who think some sort of physical "collapse" suddenly
changes the wave function when a measurement happens (and there
are disagreements about what constitutes a measurement); people
who think there's no such thing as collapse and the wave function
always evolves smoothly (sometimes with operationalist caveats
added); and people who think something else.  Most of these views
seem to be more or less equivalent in terms of predicted outcomes
for experiments.

Almost no physicist thinks today that consciousness has anything to
do with the act of measurement.  (You might say that the apparatus,
like the famous cat, is in a superposition of macroscopic states until
a conscious observer observes it; but why in heaven do you have to
make the "collapse" happen *there*?)  Nevertheless, people like Wigner
have endorsed this view in the past; it isn't entirely the creation
of magazine writers.  I think that this interpretation has little
reasoning and no evidence in its favor (as you nicely summarize)
and I agree that it's spawned a lot of garbage, but it's not
entirely been repudiated by the physics community.

Everything written about this subject tends to become seriously
mangled in the popular literature, since the consequences often
seem so bizarre.  Distortion is by no means limited to interpretations
where the act of measurement involves a physical "wave-function
collapse."  Hugh Everett's nice collapse-free "relative
state interpretation" was branded the "many-worlds interpretation"
and instantly gave rise to a host of descriptions that were as
inaccurate as they were lurid. 
 
>For example,  would there be any  inaccuracy or incompleteness in
>stating:
> 
>          "The act of interaction with a measuring apparatus
>           affects the quantity observed at the quantum level."

I'd say it affects quantities that are incompatible (don't
commute) with the one observed, but otherwise this is not
particularly inaccurate.

It's a little incomplete, in that it doesn't say what a measuring
apparatus is or how the state is affected.  Those issues are at
the heart of the disputes over interpretations of QM. 

>The point is that when a  physicist talks to a magazine writer in
>"layman's  terms", the  lay writer  (or reader)  has a reasonable
>expectation  that  the  words   correspond  to  their  dictionary
>definitions.

And, additionally, the physicist has often been using the terms
in a physicist's way for so long as to have forgotten that common
use differs, or that people usually can't tell the difference. 

The result is the sad flood of nonsense that you've chronicled.

>I'd like  to see some  of the Heavy  Hitters of Physics  come out
>with  quotable (and  above all  *understandable* statements about
>the nature of 'observation', so that people will realize that the
>universe *does*  still exist independent of  the consciousness of
>the observer.

A good place to look is sci.physics, where a lively debate on this
subject resurfaces periodically.  There are a lot of cranks there,
but in between their blatherings one can find nice posts on the
topic of measurement and QM interpretation by people who've done
some serious thinking about the subject.  It gets a bit technical
sometimes, but it gives a nice idea of both what is accepted and
what is in dispute.
 
-- 
Matt McIrvin, posting nonsense again 
Xref: sparky sci.skeptic:18051 soc.men:17837 soc.women:17832 alt.feminism:2676