X-Message-Number: 5254
From:  (Thomas Donaldson)
Subject: Re: CryoNet #5245 - #5251
Date: Fri, 24 Nov 1995 11:55:52 -0800 (PST)


And here we go again:

Mr. John Clark argues that I am only raising "engineering" difficulties. As 
readers of my original message know, I pointed out that not all materials 
provided equally good substrates either for computing or for brains. It seems
to me that "engineering" difficulties, when we become really serious, count 
at least as much as other problems. That's why I mentioned them. Yes, with
considerable effort we can make computers out a wider variety of substances
than silicon. Silicon won out precisely because it did not require all that
effort, and made something that worked better, to boot. Just what materials
we might use to make neural nets that behave as our brains do remains an open

And note, moreover, that I specifically did not say that Mr. Clark was "wrong".
I said that the materials involved needed to be considered or else he was 
raising what was, in PRACTICAL terms, a meaningless abstraction.

Moreover, Mr. Clark still shows the arrogance I have come to expect of those
who believe in Nanotechnology. We learned to fly by careful study of birds,
not the small birds but of large ones such as albatrosses, which spend much
of their time gliding. And the entire notion of neural nets, which has proven
to be more and more useful in real engineering applications (whether or not
these "artificial neural nets" imitate real neural circuits, or even claim to)
came from study of how brains might work. Yes, mammals (humans included) 
send impulses on their nerves are far less than the speed of electrical 
impulses on wire. Yet right now there is work in progress on making organic
conductors, with some success. I personally believe that the reason our 
nerve impulses are so "slow" is not because of any physical limit, but simply 
because they do their job well enough as it is (their job, of course, is to 
manage our limbs and body, both of which have physical restraints on how fast 
they can move. Right now, if our nerves worked faster, their speed would be
quite useless because nothing else would match it).

Naturally, as parallel systems, far more parallel than anything yet built, 
our eyes (for instance) can match any electrical device in their speed of 
reaction. That is because they are highly parallel, not because individual 
impulses proceed faster.

I would agree with him when he says that we can probably design ourselves 
"better". Immortalism is part of that belief. Just what materials we might
use remains an open question. And of course, as biochemical creatures,
we are basically instances of nanobehavior if not nanotechnology. That is
exactly what enzymes and cofactors do. Not only that, but despite all the
noise in some circles, nanotechnology (except for its currently major 
branch, known as BIOCHEMISTRY) has so far been little but theory. Biochemistry
however has been moving forward very rapidly. 

I too am not disinterested in theoretical issues. I would be interested in
knowing some other way to produce the features that our brain has, and do
well enough to match real brains in practical things. Clearly the only means
NOW to do that involves neurons; it would be of great interest to find other
materials, not least because, even if we don't create brains faster than our
own, we may devise materials capable of surviving environments that our 
current biological substrate cannot. But one essential point that study of 
parallel computing has led me to is that the older model of a computer fails:
not, not because it is "wrong", but because speed of computation is and will be
a major important factor if we really want to use computers for more than 
intellectual games.

As for the possibility of uploading ourselves into a computer which would then
provide a substitute reality for us, rather than actually dealing with the real
one all around us, I would say that (IF that is the only reason for uploading)
we already have means to do much the same. If you want to escape the world, 
try opium, or speed, or any one of a number of different drugs. If you use 
them you won't even CARE how fast you are. And how do we tell reality from 
a dream? Reality has this tendency to produce events that are not just 
unexpected, but that we would not have imagined in thousands of years of 
dreaming. Sometimes those events are very uncomfortable, sometimes they are
delightful. That is what happens with reality. 

			Best and long long life,

				Thomas Donaldson

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