However, I'm not sure the immune system would know to go after the
nanites. It's basically a question of whether the nanites would trigger
an immune response. Our systems are most sensitive to foreign proteins,
preferably large or with special aromatic amino acids. Synthetic
homopolymers -- only one building block -- tend not to trigger
responses. Killer cells are activated by peptide fragments displayed on
the membranes of cells containing them. (Dextrorotary amino acid
proteins tend not to trigger an immune response, because our enzymes
only break down levorotatory amino acids.) On the other hand, "large,
insoluble macromolecules are good immunogens" so I don't know how pure
carbon nanites would be responded to. Presumably someone could get some
idea by injecting small carbon particles into a lab mouse and seeing
what happened.
As I said, carbon-nanites are probably an overrated threat, due to the
flammability problem. I'll give you some more threatening ideas:
(1) bacteria based on right-handed proteins and sugars, but equipped
with tools for dealing with both orientations themselves. No natural
life would be able to digest them (usefully; they'd probably die in
stomach acid) but they could go through the biosphere. I have no idea
of what's involved in reversing the handedness of an amino acid --
possibly breaking it down and rebuilding it from scratch. That would
probably put a kink in their style, but they could still be annoying.
(2) Rock-nanites, based on AlO, SiO, or relatied mateirals (quartzoid,
sapphireoid.) Their elements are as abundant as carbon, and they're
already burnt, so the flamethrower attack won't work. They'll probably
still be low in entropy, and they'd have to be disassembling biomass for
the hell of it, not because they were using it to grow themselves
(except as an energy source, perhaps.)
Of course, I don't think anyone's really working on sapphire nanites.
People who worry about this should hope that Carl's progression is
wrong, and that we do start with bucky/diamond nanites. Rampaging
mistakes at that level will be easy to control. Then by the time more
resistant nanites start wandering around strong nano-defenses would
already be in place.
Merry part,
-xx- Damien R. Sullivan X-) <*> http://www.ugcs.caltech.edu/~phoenix
Humans humans pay your dues
As never before you get to choose;
Become like us or fight and lose,
Great Ones evermore.
Powers evermore.