X-Message-Number: 21194
Date: Mon, 17 Feb 2003 08:15:37 -0500
From: Thomas Donaldson <>
Subject: CryoNet #21179 - #21192

For James Swayze:

I began my discussion of respirocytes by pointing out that that they
did not now EXIST. This makes their evaluation in comparison with 
present ideas for similar systems to be quite difficult, since after
all dreams always turn out better than reality. Nor do I think that
any amount of previous calculation will solve that problem.

Your note raises lots of issues, more than I can go through briefly.
I would be happy to BUY Freitas's book, if I knew where to go to 
do so. 

However I will begin with a basic issue. Evolution has NOT CEASED.
It simply bears on different traits than those it bore on before.
If I choose to make a modification of myself, and this modification
doesn't turn out as well as I'd hoped, that is evolution in action.
For that matter, external events will also affect our evolution,
just as they always have. It's just that their effects will be 
mixed up much more with our choices in responding to them.

Your advantage to respirocytes, when examined, looks quite weird. 
OK, so now we have this guy with artificial blood which does not
require oxygen as often as we do, and HE SUFFERS A HEART ATTACK?
Now wait a minute here! You seem to be proposing that we will 
someday have this marvellous nanotechnology, complete with 
respirocytes, but still suffer from HEART ATTACKS? No doubt our
respirocytes will also protect our brains from strokes, etc etc.
I hope you understand just how weird such a world would be. At
one time I wrote an article for ANALOG pointing out all the 
stories full of interstellar flight, teleportation, etc etc etc,
in which the level of medicine remained that of the early 20th
Century. That is ABSURD.

(As a side issue, a heart attack occurs when one area in our 
heart muscle becomes deprived of blood flow. A stroke occurs
when one area in our brain becomes deprived of blood flow.
So does this mean that the respirocytes in these areas turn
themselves off while all the others continue working?)

In real life, we do not try to protect ourselves constantly
against all kinds of natural or human threats regardless of
the cost of doing so. Respirocytes would not only have to have
the ability to protect us, but also cause us even fewer
problems in keeping them active than our present blood system.
Even just the engineering and design problems in doing that
makes them harder to do than they look. It's exactly that point
that I was making when I said that our evolution had worked
to optimize (note that word) our blood system. Yes, what is
optimal for people living in one environment may not be 
optimal for those living in another "more modern", but that
does not change the problem.

I am sure that this will not answer all your questions, but
it's my bedtime now and I want some sleep. More later.

               Best wishes and long long life for all,

                     Thomas Donaldson

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