X-Message-Number: 14158
Date: Sun, 23 Jul 2000 23:39:45 -0700
From: Mike Perry <>
Subject: Re: Ettinger's Survival Quickies

Bob Ettinger, #14142, writes in part:
>3. Mike Perry points out that your far-future self might still be interested 
>in history, and especially in the history of you, of whom he is the remote 
>That's true, and possibly comforting to some people, but not really relevant 
>as far as I can see. Why should it matter to me, now, if in the far future 
>someone else (whether or not my own continuer) will think about me?

My future continuer will not be simply "someone else" but *me*--grown older,
wiser, and I think, a greater being all around. I don't fear that this
person will be "different"--and thinking about this possibility *now* is
reassuring in a way that any contrary possibilities could never be. It does
matter. It is not the only thing that matters, however. Benevolence, I hope,
will so prevail in a world of the far future that all should be valued by
all in ways not possible today. This I think will follow from considerations
of enlightened self-interest on the part of those who are around then, self
hopefully included.

>Others have said that, since "you" change over time anyway, a near-duplicate 
>at the same time might be more "you" than your continuer at a later time. 
>More similar, sure, but that doesn't really touch the basic problem, which is 
>that we just don't have any sound or proven criterion (or set of criteria) to 
>gauge "identity," nor do we even know how to state the question clearly.  

In my view we are rather close to a reasonable theory of identity, based
around computation, but the theory (or almost-theory) itself is still far
from having general acceptance.

>Mike Perry also says:
>>Sure, a measurement "proves" that you have two particles that are separate 
>and >distinct. But in making that measurement, you have also put them in 
>different >quantum states. When the states are the same, the behavior of the 
>total system >is such that you have to treat them as identical.
>"have to"? Only for some purposes. (And even if the act of measurement 
>changed the states, it did so separately to the separate particles, and they 
>are still distinct from each other.) 

The point of view of Tipler et al (self included) is that you have a number
of "particles" that range over exactly the same set of states and actually
are one and the same object. You don't have one particle that's over *here*
and another *there* for instance. Both particles (speaking loosely) are
*both* here and there equally until measurement separates them! In other
words, they both possess the same, identical family of states with
associated probabilities, and so can be said to constitute one entity. The
act of measurement itself splits one entity into more than one.

>If I detect one alpha particle here, and 
>another there, I certainly don't have to treat them the same way.

Yes, but in so doing you have put them in different states, violating the
condition that they were originally in, and in effect, splitting one,
original object into two.

A discussion of these points will be found in *The Physics of Immortality*
pp. 230-233, and some further clarification is provided by P. Forrest in
"Identity of Indiscernibles," from the article "The Impact of Quantum
Mechanics," *Stanford Online Encyclopedia of Philosophy* (1996)

Mike Perry

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