You're right that nanites could reduce unliving matter to lower chemical
energies for energy. But there are several caveats:
Rock is mostly out. Some of it might be tappable, but the density would
be very low; you'd have to chew huge volumes to do anything.
Biomass is energy-rich. But it's a limited source. If you turn a large
fraction of biomass into nanites I suspect the remaining fraction won't
power their activities for very long. Also remember that only 20% of
living or recently dead biomass is useful as feedstock or fuel, because
the rest is water, one of the most useless substances for mech-nano. So
if defenders can constrain the progress of a pool of goo it could run
out of fuel soon unless it went solar, and solar can be cut off.
} religious fanatic that wants to destroy the world. The basic issue
} has been whether a private (non-global) immune system can deal with
} this threat.
Scenario: New York City is the last city left. All other continents are
a seething mass of grey goo, released by the first "nano-power", which
is also the religious fanatic above. This goo is fuel- or
solar-powered; does not have internal communications, and thus doesn't
do dynamite or nuclear bombs; and is made of aluminosilicates, so it
won't burn. How NYC survived to this stage I'll ignore, but I'll assume
it has acquired some stockpiles as necessary. Also that NYC has more
researchers than any single lab.
First line of defense: shaded concrete moats. Convertible into nanites,
but very energy poor. Nanites crawling over the surface (probably not
in a straight line, I'd guess random walk strategies are used) get
washed off by water hoses. NYC has plenty of water available. This is
probably a temporary solution, especially if the nanites anchor
themselves to the surface at each step (that should slow them down?) or
can tunnel underground (sink concrete curtains, then they won't have
energy to go through.) But that's okay.
Since the beginning of the crisis researchers have been working on
captured nanites. Obviously they're looking for countermeasures --
chemicals which will gum up the nanites, or dissolve them, or
something. But they're also busy figuring out how the things work; by
releasing the nanites the "nano-power" has thrown away its only
advantage. Perhaps the NYC researchers will be able to come up with a
predator nanite for the goo, which they then release around the
perimeter. Counter-goo! Or should I say Bronx-goo? Defeated nanites
and recaptured land become new resources for the counterattack, solving
the problem of limited resources. Soon New York has conquered the
world.
No global immune system; no private nano-immune system to begin with.
Just physical barriers which hold until superior intellectual resources
outfight the attack.
} mobiliy to the nanites themselves, would be that somebody sprays them
} over a forest from a small aeroplane during the night. Most people
Scenario: these are presumably carbon-based nanites, if they eat wood.
The forest is quickly consumed into a huge lake of goo, but the area of
the lake can only spread so far -- only the perimeter nanites are
useful. In the meantime it's been noticed, and someone ignites the
mess, causing possibly the world's larges fuel-air explosion. This
scatters lots of nanites all over the place, leading to the "nano-Pern"
scenario: people rush out to find growing puddles of nanites and
flamethrower them. Concrete houses become a big fad. Again, nanites
are quickly captured and analyzed, this time by a research establishment
dwarfing that of the previous scenario. Life is unpleasant, and the
ecosystem is having lots of holes eaten in it, at least at first, but
total destruction is not imminent.
} > Personally I'm still suspicious of this conception of nanites. Little
} > atomic manipulators made of a single type of material
} No, nanotechnology makes use of many types of materials.
The "designs" I've heard of have been of single types of materials, or
limited families of materials. They supposedly can manipulate anything,
but it's all made of diamondoid. The flammability of which no one seems
to have addressed.
} > environments, and being able to take over the world in their first
} > generation.
} No, not in their first generation. Even when nanotech itself is
} mature, the "little atomic manipulators" have to multiply themselves
} many times over before they reach macrosopic quantities.
First design generation, unless this is some nihilist fanatic who is
willing to have evolving nanites.
Merry part,
-xx- Damien R. Sullivan X-) <*> http://www.ugcs.caltech.edu/~phoenix
Do not look upon this glass,
Lest your soul from this world pass
This legend burned upon its case
You dare not see the mirror's face.