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

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