Life in an Open Universe

Bryan Moss (
Thu, 3 Sep 1998 14:37:41 +0100

I'm not sure if this made it to the list or not. If it did, here it is again. If it didn't, then please feel free to answer my questions.


A few questions about life in an open universe as
described by Dyson in TIME WITHOUT END: PHYSICS

Dyson chooses a model in which "human-sized
objects will disappear [within 10^(10^26) years],
but dust grains with diameter less than about
100mu will last for ever". He later proposes that
if this is true life may have to exist as "a large
assemblage of dust grains". Does this mean that
after the elapsed 10^(10^26) years anything over a
100mu diameter would be unable to exist, or merely
that such an object would take that many years to
decay? His later statement about the biology of
future life (the "assemblage of dust grains")
suggests the former, but I'm not sure.

The most interesting thing about Dyson's scenario
is that it imposes a number of limits. These
limits make it easier to predict what life could
`evolve' into. (Tipler's Omega Point in a closed
universe relies on omniscience and is therefore an
omniboring area of conversation.) For instance,
the need for an infinite amount of memory storage
(Dyson suggests analog memory) "will put severe
constraints on the rate of acquisition of
permanent new knowledge". He also proposes scaling
laws, the need for hibernation, and limits to
communication. I'm sure an even better model of
future life could be created. For instance, are
there any fundamental limits to complexity that
would stop *really big* Jupiter Brains from
functioning (increased complexity generally means
more errors and more redundancy)? Will limits to
communication (speed of light, background
radiation) and size (spread of matter in the
universe, rate of decay) insure individuality?