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From: mikes@AMES-NAS.ARPA
Newsgroups: net.physics
Subject: none
Message-ID: <525@sri-arpa.ARPA>
Date: Fri, 30-Aug-85 19:52:43 EDT
Article-I.D.: sri-arpa.525
Posted: Fri Aug 30 19:52:43 1985
Date-Received: Mon, 2-Sep-85 04:01:05 EDT
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From:  mikes@AMES-NAS.ARPA (Peter Mikes)

 RE:  Many Worlds and other Interpretations of QM
Status: R

in reply to: hplabs!sdcrdcf!sdcsvax!davidson@UCB-Vax.ARPA (Greg Davidson)

   Hi Greg,
            I am atempting to understand what you are saying - and am
  not sure how well I did so far. So I would send this directly but I have
  problem with your address.
   I am seriously interested in alternate interpretations of the QM - and I
  would really like to get your view. I am not on level of agreeing/disagreeing
  yet - just attempting to align the terminology.
Greg:
First suppose that every elementary event occurs in all possible ways by
forking off a whole universe for each possible outcome of the event.  For
``observers'' along any world-line, it is irrelevant (because unobservable)
whether some outcomes are more probable, or whether all are equally likely.
It is also irrelevant whether outcomes are constrained by some ``laws of
physics'' or whether all conceivable outcomes generate universes.  Note
that the latter is a simpler theory, hence preferable by Occam's razor.
POM:
   First - it seems that what you are describing is not (what is usually
           called) MW (Many Worlds int) - I would suggest to call it 
                   AW ( All Worlds). [ I did not read Everett (either?) ]
            - but let's take his book as definition of MW. In MW (I think)
           not all possible ways are assumed - it just considers outcomes
           which are compatible with QM.
Greg:
Now in such a system, the notion of observer is rather bizarre (hence
my earlier quotes).  Particle configurations identical to what we think
   	TRUE. ( for AW)
So to summarize, MWTs do violence to the notion of observers, and thus
to the practice of physics.  To belive in a MWT is to believe ourselves
    	TRUE. ( for AW )

> [1]  Not all the alternate worlds are equiprobable!  [2]  There is no
> observable difference between the alternate-worlds QM and the
> Copenhagen QM.
[1] Maybe, ....., Occam's razor would suggest
abandoning any theory of structure in the generation of successor worlds.
    	NOT clear why - pls explain.

Thomas M. Breuel wrote:
> [1] The 'multiple worlds interpretation' of QM is not a physical theory:
> you cannot design an experiment to disprove it, since it postulates that
> there is not interaction between its different worlds.
[1] Many physical theories give the same results.  Ptolemaic epicycles
    
    POM:    It is not a theory!  (most believe it is 'only' an interpre-
 tation of QM. I consider it a mere rephrasing of CI ).

  Are there other interpretations?
	   Yes. I have mentioned at least three other interpretations which are
 	 significantly different ( Pilot wave, Q. potential and 'subvac' )
   	Didn't you noticed?