[ExI] Silence in the sky-but why?

[Adrian Tymes]

On Tue, Aug 27, 2013 at 6:32 AM, spike <spike66 at att.net> wrote:

>
> Subject: [ExI] Silence in the sky-but why?
>
> Anders tackles the Fermi paradox.
>
> <http://phys.org/news/2013-08-silence-skybut.html>
>
> >...'We still don't know what the answer is, but we know it's more radical
> than previously expected.'
>
> ------------
>
>
> Of all the observed scientific anomalies that I know of, the misnamed Fermi
> paradox is absolutely the most vexing.  The more we study that question,
> the
> more clear it is that there is something fundamentally wrong with our
> models
> of everything we think we know about intelligence, evolution, space travel,
> everything.  If our current understanding of these things is anywhere close
> to correct, there has been plenty of time for intelligence to evolve and
> colonize everywhere in the visible universe, and the signals between
> civilizations should be easily detectible.
>
> After pondering all the possibilities, I am forced to conclude that
> apparently intelligence is inherently self-destructive or self-limiting,
> and
> that our current level of intelligence on this planet is anomalously high.
>

Why is that error more likely than, say, our error rate in calculating how
unlikely intelligence is to arise in the first place?  Sure, there are
billions and billions of stars - roughly 300 billion in the Milky Way,
which has been around for 13.2 billion years.  Let us assume that the Milky
Way has had roughly a constant star population since its formation.  That
gives on the order of a trillion star-five-billion-year periods.  It's
taken 4-5 billion years for intelligent life to arise on Earth, so perhaps
it makes sense to speak of the odds of life arising around any given star
in a given five billion year period.

If the odds of intelligent, tool-using life with the potential for space
travel arising around a star, in a given five billion years of the star's
lifespan, is somewhere around one trillionth (readily justifiable when you
multiply together all the factors it would need to overcome, even before
the species gains the capacity to wipe itself out), then we would indeed
expect there to be exactly one intelligent species by now - and here we
are.  Not counting anything we create, we could expect on the order of
another ten billion years before another species like us came along.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20130827/0c664f12/attachment.html>