X-Message-Number: 14454 From: "Daniel Crevier" <> Subject: If so, where are they Date: Tue, 12 Sep 2000 13:59:55 -0400 I'm no cosmologist, but I understand that the universe is made of "lumps" of matter, which can be either galaxies or galactic clusters. The size of any given lump remains more or less constant, but the expansion of the universe makes the lumps move away from each other at ever increasing speeds. So if you are in a lump, after a while all the other lumps will move away from you at close to light speed, which should make them unreachable even for a very advanced civilization. Thus, even in an infinitely old, infinitely large universe, the number of star systems reachable by any civilization may well be finite, and li- mited to the lump the civilization develops in. If a lump cannot contain more than a few civilizations, this could explain why we haven't seen any aliens yet. Daniel Crevier Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=14454