Symmetric Chaos
Fractal King
From GURPS: Space by Jon F. Zeigler and James L. Cambias
Ammonia could replace water as a
medium for life. Ammonia has a narrower
liquid temperature range than
water, so it would require a planet
with a very stable climate between -
108° Fahrenheit (-78° C) and -27° F (-
33° C). In that cold environment, it’s
possible for something like Terrestrial
nucleic-acid chains to function, or for
complex chains of nitrogen or carbon
and nitrogen to serve the same purpose.
Since complex nitrogen molecules
become highly unstable at liquid-
water temperatures, ammoniabased
organisms could be made of living
high explosive! (This does not
require the Explosive disadvantage,
however, because the temperatures
involved would kill the being
long before its molecules became
unstable.)
Ammonia-basedlife could conduct
photosynthesis if it evolved on a cold
Earth-type planet, or might tap the
heat differential between layers of a
gas giant world’s atmosphere. Such
creatures probably would not be oxygen-
breathers, since the chief source
of oxygen molecules for Earth-type
life (carbon dioxide) is a solid at
ammonia-life temperatures. Instead,
ammonia-based organisms might
breathe free hydrogen, either in a gas
giant atmosphere or liberated from
methane molecules on a cold
Terrestrial world.
Living creatures based on ammonia
should define their Temperature
Tolerance range as centered somewhere
between -100° F and -25° F;
they are not automatically Cold-
Blooded in the sense defined by the
disadvantage of that name, however.
Hydrogen-breathers may take the
disadvantage Fragile (Combustible) if
they spend lots of time in oxygen environments,
as their “air” can catch fire.
Since chemical reactions are slower at
ammonia temperatures, either a low
Basic Speed or Decreased Time Rate
might be appropriate.