X-Message-Number: 5254 From: (Thomas Donaldson) Subject: Re: CryoNet #5245 - #5251 Date: Fri, 24 Nov 1995 11:55:52 -0800 (PST) Hi! 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 question. 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 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=5254