On Mon, 26 July 1999, Billy Brown wrote:
> There are several big mental pitfalls that you have to avoid when
> approaching this subject.
>
> Exaggerated Respect for the Immensity of Space
> The galaxy is big, but it isn't infinite. A single expansionist species
> with sublight travel could easily colonize every single system in it in
> less <10^6 years. Suggesting that we are surrounded by aliens, but they
> don't happen to have visited us, is equivalent to sugggesting that a
> particular lot on Manhatten Island might remain vacant for the next million
> years.
I'm not sure I agree with this. The universe is in fact extremely large, with our galaxy making up a very small part of it. It is possible that space-faring intelligences are so rare that they only pop up in 1 out of 1000 galaxies. If they are that rare, and given the relatively young age of our universe, this doesn't give them enough time to find us. Afterall, we are but a speck in a speck. And if inflationary theorists are right, then our observable universe might be as small as a 1/10^30th of the actual Universe. Now that's a speck within a speck within a speck if I have every heard one. :-)
Paul Hughes