gray goo
n. A hypothetical substance composed of sagans of
sub-micron-sized self-replicating robots programmed to make copies
of themselves out of whatever is available. The image that goes
with the term is one of the entire biosphere of Earth being
eventually converted to robot goo. This is the simplest of the
nanotechnology disaster scenarios, easily refuted by arguments
from energy requirements and elemental abundances. Compare blue goo.
