| Subject: Re: Are aliens hiding their messages? (was: Fermi paradox) |
| From: Erik Max Francis |
| Date: 31/07/2003, 18:51 |
| Newsgroups: rec.arts.sf.science,sci.astro.seti,alt.sci.seti |
Victor wrote:
For those interested enough to pick up a good book on the subject:
...
Given the fact that there are perhaps 400 million stars in our Galaxy
alone, and perhaps 400 million galaxies in the Universe, ...
Except these numbers are 400 billion and hundreds of billions,
respectively.
... it stands to
reason that somewhere out there, in the 14-billion-year-old cosmos,
there is or once was a civilization at least as advanced as our own.
Non sequitur, particularly the "at least as advanced as our own." The
problem here is that the Universe hasn't been able to harbor life forms
until just recently; the primordial Universe was nearly all hydrogen and
helium. How recently, we can't say; it depends on a lot of things we
really don't know, like how frequently life develops on a suitable world
(e.g., was the time it took life to evolve on Earth unusually fast, just
about average, or unusually slow?), and the precise ratio of "metals"
(in the astronomical sense) required to develop life, intelligence, and
a technological civilization, and so on.
It's certainly possible that the Universe has been capable of harboring
intelligent, technological civilization for a billion years or so. But
then, it's also possible that life is just hard enough to come by that
we're on the first wave of technological civilizations in our Galaxy,
where we're either the first, or the other civilizations of our
"generation" are clear on the other side of the Galaxy and very few.
The point is, we don't know. Saying, "Wow, there've been 14 billion
years for civilizations to develop!" is inaccurate, however.