X-Message-Number: 7952
Date:  Wed, 26 Mar 97 12:21:26 
From: Mike Perry <>
Subject: Re: CryoNet #7941 - #7944

Bob Ettinger wrote

> It is simply a fact that NONE
> of the usual intuitive survival criteria, nor any combination, can be shown
> to be EITHER necessary or sufficient--not continuity of matter, not identity
> of matter, not continuity of pattern, not identity of pattern. It is not
> possible, and in my opinion not psychologically necessary, to form a firm
> opinion before we have the necessary knowledge of biology and physics. So,
> once more, we just use common sense, freeze our assets, and hope for the
> best, while continuing to investigate.
> 

"Identity of pattern" would, to my 
satisfaction, be sufficient (not necessary, however, inasmuch as you 
could be said to survive in a continuer, which is not identical to 
you). This is a central point of the book I am writing, and  I'd
be interested in any comments as to why, if what I mean is
reasonably understood, it would NOT be sufficient. The 
objections, as far as I can see, all amount to forms of vitalism or a 
non-reductionist "further fact" about what constitutes our identity.
At any rate, I second Bob's advice to "freeze our assets and 
hope for the best, while continuing to investigate." 

Thomas Donaldson wrote

> Now look here. Are you really saying that everything is 
> symbolic? Not representable by symbols, but actually symbols themselves?

I am inclined to think that a universal language could be 
developed to describe "everything." It would describe the quantum 
state in an economical way. (Indeed, something like this probably 
already exists.) The quantum state of a bounded system has a finite 
description. Would I say that such a language "is" reality? I'll say 
that I think it would be isomorphic, in a mathematical sense, and 
probably in a rather strong sense (since more than one isomorphism is 
possible between mathematical objects, and we then must ask whether 
we are dealing with the "right" isomorphism). If such a language did 
exist, it would make it clearer how to emulate processes in the real 
world--it would be straightforward to map a process in a computer 
that used this language into a "real" process, and vice versa. The
possibility of doing this, in principle, seems strongly suggested by 
arguments such as the finite state machine argument of Tipler, 
despite some complications with that idea (see below).

> I doubt that completely, unless perhaps you have decided to redefine 
> the world "symbol" so it includes everything... in which case you are
> saying nothing at all. Who attaches meaning to these symbols, anyway?
> Without that, you have no symbols.  
> 

I haven't "decided to redefine the [word] 'symbol'." I am talking 
about a language over a finite alphabet--each letter being a 
"symbol"--each "sentence" being a finite string of such symbols.
The alphabet could just as well contain 2 symbols only, say 
O and X. As for "who attaches meaning"--consider the
following string of symbols:

OXOXXOXXXOXXXXOXXXXXOXXXXXXOXXXXXXX

Now consider this string:

OXXOXXXOXXXXXOXXXXXXXOXXXXXXXXXXX

I haven't "attached any meaning" to either one, yet I bet you could 
say something "meaningful" about both--they are not just random 
noise. More generally, I think that strings of symbols could encode 
mathematical properties that should be decipherable to intelligent 
aliens who have no knowledge of our languages or civilization, or 
what we are like physically. Mathematics would make a 
powerful starting point for conveying ideas in general, and I think
this could be done too. We might then say that
a message in such a language would "have a meaning" we 
didn't have to "attach" in the sense that aliens could pick up on it 
without our instructing them, other than through the message 
itself--and other messages in the language. Reality is like that too. 
If we could reduce its "messages" to pure digital form, and think of 
them that way, it wouldn't preclude our finding "meaning" in them.


> As to whether or not we are finite state machines, I remain dubious. One
> issue coming directly from quantum mechanics is that not ALL measurements
> (in theory) have a quantum character. For instance, momentum is a vector,
> and its value as a vector -- a direction in space --- is not quantized,
> though the relation between position and momemtum is. That alone raises
> questions about whether quantum mechanics says we are finite state 
> machines. In practical terms, our components undergo constant renewal,
> so that their quantum states will constantly change. This means to me 
> that any attempt to really list the finite number of states we are in will
> fail --- not because of its number, but because it changes all the time.
> Sure, we can make generalizations, but then we will lose that finite
> character: an infinite set of molecules can be in the right conformation
> to produce ME or YOU.
> 
There is a complication with the finite state machine model of real 
world phenomena, in that such machines must always be "embedded" in 
their surroundings. (An FSM, however, can be interconnected to other 
FSMs, through input-output relations.) An infinite universe
would not be a finite state machine, nor an immortal person. But the
FSM model, even taking account of the
(hopefully) infinite character of reality as a whole,
does at least strongly suggest that we are digital processes, and 
thus, exactly emulable in a purely symbol-manipulating device (which 
must also have appropriate links with the outside world to model the 
embedding). But this seems contrary to the view you express: 

> 
> One major distinction between (say) Crays and human beings comes down to
> the issue of whether they operate with symbols or work in the world without
> using symbols (at root). I am saying that this distinction is key.
> 

Can you "work in the world without using symbols (at root)"? The 
message from quantum mechanics, whatever the character of some 
measurements, etc., seems to be no. This is because the quantum state 
is held to provide the complete description of a system--or, as Tipler 
says, to *be* the system. The description in turn is finite (again, 
for the bounded case), and the way it changes over time is describable
by an FSM. The states change rapidly, as you say, but we could, in 
principle, enumerate all the *possible* states a system could be in for a 
long stretch of time. We would then know that the system is popping 
back and forth between various of these states according to known 
rules--even if, in practice, ascertaining exactly which states
at which times may be impossible. Again, the practical difficulties
don't seem to stand in the way of this being a digital world.

Mike Perry

http://www.alcor.org

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