OFF: SETI, ETs

[M Holmes]

Stephen Swann writes:

> M Holmes writes:
> >
> > jean l delacour writes:
> >
> > >   First of all, there were numerous lectures by such UFO experts as Micheal
> > >  Lindemann & Bud Hopkins.  They were very convincing and insightful.  They
> > >  pointed out that it is COMMON KNOWLEDGE within the scientific community now
> > >  that ETI's are infact out there.
> >
> > Who's this "scientific community"? It's commonly believed that it is
> > *probable* that there are other intelligences but not a lot of people
> > suppose that they visit little old us.
>
> I take it you mean "probable", in the sense of non-zero probability?

Yes.

> I remember some really *really* heavily rounded off numbers being
> thrown into a fairly off the cuff equation, which basically estimated
> how many planets out there might exist that could support anything
> remotely like earth-based life.

Yes, that was quite a famous analysis for a while.

> That of course tells us nothing really important, because what is the
> "probability" that a planet which is "capable" of supporting life will
> spawn it?  If you use Earth as your sample, then the probability is
> 1.0, and it's a crowded little universe out there.  ;-)

Things seem to be running more Fred Hoyle's way and the idea of
pre-organic molecules being created in space is more fashionable.

Then there's Prof Cairns idea that replicating slate/shale near tidal
pools created organic molecules by accidentally creating conditions for
chemical engineering. That would necessitate a planet with a relatively
large moon. We don't know how probable that is either...

For the other side, I was reading some Jared Diamond recently and he
discussed the question. He notes that the ecological niche of the
woodpecker wasn't filled in the ecology of Australia/New Zealand. The
implication being that even in parallel evolution, all niches are not
necessarily filled. It may be that sentience is some weird and rare
evolutionary accident.

> Steve

FoFP