X-Message-Number: 21022 Date: Fri, 31 Jan 2003 07:29:25 -0500 From: Thomas Donaldson <> Subject: CryoNet #21007 - #21020 For Mr Kluytmans: I was not, at least directly, claiming that biological systems would be more efficient. Your message said that biological systems provided a proof of principle for the existence of nanotechnological systems. I pointed out one way in which they were quite clearly different from nanotechnological systems, at least those you were talking about: they ultimately came not from anyone's design but from the operation of statistics on chemistry for several billion years. AND because I have studied brains a good deal (brains are biological systems) I raised the question of whether or not living systems might tell us that the kind of nanotechnological devices you envisioned just wouldn't be so easily made that they could compete. I raised a question, but did not directly answer it. I WILL point out that in real life at least one factor which you don't mention in your message becomes quite important: the energy cost of making a device in the first place. Sure, the device when made may use far less energy than a living cell, be packed more tightly, etc etc. But how much will it cost to make? To give an example of how important that MAY turn out to be (not an entirely serious example, because I doubt that either of us has good enough figures) suppose we made our devices of highly crystallized platinum. Platinum is hardly a common element, and just bringing it together would cost a lot more than getting together the hydrogen, carbon, oxygen, etc of which living things are made. Nor would means to make your platinum nanodevices in great number make any difference to their basic cost. They would just multiply that cost by the number of devices you made. Along the way, in my message I explained one way in which that cost may show itself in the real world. Living things work by the statistics of chemical reactions; even though enzymes can and do place atoms in particular locations, this process isn't the kind of manufacturing process you seem to envision, in which nanosystems carefully and exactly do the same thing... to make more nanosystems. The construction process you propose (not that I think you are alone) COULD turn out to be expensive enough that it just isn't practical when compared with how living things are made. (Not that if this were so, we could not use similar reactions to those of living things to make our nanodevices!). Basically I was pointing out one issue which some proposals for making nanodevices don't consider. I don't know myself just how this issue will fall out in the real world ... though things that we forget to consider often show themselves by biting us where we least expect it. In any case, if YOUR proposed systems are too costly compared to the kinds of nanodevices based on chemistry and biochemistry, then no one will buy them. If they are put out to compete with living things, living things will win, not by being more efficient or superior, but simply by numbers alone, while your nanodevices struggle to reproduce themselves only a few times. Most important, I was raising a possibility and posing a question based on that possibility, not simply asserting one thing or another. Best wishes and long long life, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=21022