Fermi's Paradox

On 9/8/12 5:22 AM, brooksn wrote:

> Thinking on this, I wondered if we came upon an alien species. Observed
> it for a time unnoticed. And found the species to be violent, both
> personally and between groups of individuals, contain weaponry with 10
> times the potential to destroy the planet they were on, polluted the
> planet to a degree that caused mass extinctions and threatened the
> habitability for their own existence and lastly was intelligent and
> technologically advanced. Would we make contact? In other words would it
> be wise to contact ourselves if we found a planet with species just like
> us? I'm thinking no.

I don't think we're as bad as all that. But the fact is, we wouldn't
have even been "we" when the aliens came -- we would've more likely been
small furry mammals scrabbling around in the dirt. Consider that humans
are only about 100,000 years old (taking a reasonable though arbitrary
point to call "now human"). Even that is a pretty short span of time on
a galactic scale -- ET would most likely have completely settled the
galaxy millions or hundreds of millions of years before that.

So this boils down to the "nature preserve" hypothesis: the galaxy was
settled long ago, but our solar system (perhaps because of its planetful
of indigenous life) was declared off-limits and left alone. This of
course implies that ET is right next door, knows darn well that we're
here, and is choosing not to reveal itself. (So our attempts at SETI
will continue to fail.)

The other major Fermi Paradox hypothesis, of course, is that the galaxy
is empty. Life (or at least technological life) is a really, really
rare fluke, and we're it so far. (So our attempts at SETI will continue
to fail.)

Unfortunately, these two opposite hypotheses make exactly the same
prediction for SETI, which is why SETI is not likely to ever prove a
useful experiment. However, they do make different predictions in other
ways; for example, the first one predicts that when we look out into the
galaxy, we should see some signs of large-scale engineering (Dyson
spheres for example).

But so far, we've seen none of that either, and so I put more stock in
the second hypothesis.

Cheers,
- Joe