X-Message-Number: 14202
Date: Sat, 29 Jul 2000 12:23:40 EDT
Subject: individuality, Norton, Pizer

First, just a little more on "indistinguishability" of "individual" particles 
such as electrons. Obviously, discussion here can only be minimal, but I just 
want very briefly to indicate some authorititave comments. 

David Bohm (QUANTUM THEORY, Prentice Hall, 1951) notes that 
"distinguishability" or its lack relates to the overlapping of wave packets 
associated with the particles, which means in essence that particles far 
enough apart can be considered separate, otherwise blurred. "If these wave 
packets overlap, then it becomes impossible to identify a given electron by 
tracing its trajectory." 

In most cases--outside of an individual atom--the overlap is negligible, so 
the electrons are separate, even in the standard quantum view. And I cannot 
overemphasize that interpretation of quantum theory continues--after a 
century--to be highly unsettled. What we know is probably still only a pimple 
on what we don't know.

And I can't help repeating that, if one were to insist that all electrons are 
the "same" (in ALL respects) then that seems equivalent to saying there is 
only one electron in the universe--a view which has actually been proposed, 
but finds few takers, and boils down to language chopping.

Likewise, if one insists that duplicate or near-duplicate people at different 
locations in space or time are the "same," then you have to add that they are 
different "instantiations," which throws back into obscurity what you mean by 
"same," or why it is valid to call them the same. So far, to my knowledge, 
all writers expressing definite opinions here have merely expressed their own 
leanings or hopes or preferences, nothing like proof. (I look forward to 
reading the final version of Mike Perry's book.)
In connection with the Quantitative view of identity, Brook Norton (#  14195) 
writes, in part: 

>duplicates exist in different space, made of different molecules, with two 
separate self-circuits      ..The duplicates are similar but not the "same" in 
some identity-linking way   ..The Quantitative view has no problem with 
duplicates.  It says they are different entities but with similarities.

His version of the Quantitative view is not mine. My version (my version of 
this view, not my opinion) is that there ARE no "identity-linking" types of 
similarity--there are only objective kinds and degrees of similarity. This 
view avoids (most) problems by dodging most issues. It takes no stand on 
which similarities are "important" or what degree of similarity is necessary 
for various purposes.
Dave Pizer's view probably comes closest to the "common sense" approach and 
the one that recommends itself in the interim. You will (probably) survive if 
your meat is frozen and then repaired, and substitutes are moonshine, albeit 
sometimes comforting. 

Robert Ettinger
Cryonics Institute
Immortalist Society

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=14202