Jurassic intelligence (time-scale for evolution of alien

[Mike Bonham <bonham@jade.ab.ca>]

Tom Myers  tommy@cs.colgate.edu wrote:

>   I won't be surprised if we go out into space and find lots of planets in
> which the Cambrian explosion never happened, because I haven't the slightest 
> idea why it happened here or why it took billions of years for bacteria to 
> get together. I will be surprised if we find multicellular life with 
> organized nervous systems which is more than a billion years old and yet has 
> not developed intelligence. It seems to me that we came close lots of times, 
> and if we hadn't hit it with people we would have hit it sooner or later 
> anyhow.
>   thoughts?

Carl Sagan presented an argument that we may be alone, despite great odds
of finding life in the galaxy, in his and Shklovskii's 1970's-ish book
`Intelligent Life in the Universe'.

Starting with the `Drake equation' where various conservatively-estimated
probabilities are multiplied together (probability each star has planets,
fraction of planets suitable for aqueous life, probability life actually
arises, probability life becomes multicellular, probability intelligent
species arise, probability technological civilization arises, fraction of
the galaxy's lifetime thatcivilizations last...etc.  This gives a very
small fractional probability that a star has detectable intelligent life,
but then gets multiplied by the huge number of stars in the galaxy,
yielding a number in the tens of thousands for the expected number of
concurrently-existing technological civilizations.  We haven't (yet)
noticed any of their effects on their stellar environment, intercepted
their communication signals, etc.

Moreover (!), if any single one of them decided space exploration and
colonization was a GOOD IDEA (TM), it would only take a couple of hundred
thousand years at sub-light speeds achievable by presently-envisioned
rocket technology, to spread to all habitable star systems in the galaxy.
They're not here (side-stepping the UFO enthusiast's protestations that
they ARE here!)

So, it must be that intelligent technological life (oxymoron?) is a lot
rarer than we thought, civilizations destroy themselves soon after they
arise, aliens really are out there but are hiding, and/or they reveal
themselves only to those who won't be conclusively believed (and how
intelligent is that?)

If intelligent dinos lived, couldn't they have been like the other
galactic minds and been undetectable? :-)
----
Mike Bonham        bonham@jade.ab.ca      Jade Simulations International
``So, here I am, sitting by myself, talking to myself.  Now THAT's chaos!''