Re: New York Times re Fermi's Question

Alfred A. Aburto Jr. replied:
> > "Joseph Lazio" <[EMAIL PROTECTED]> wrote in message
>
> news:[EMAIL PROTECTED]
>
> > > > > > > "R" == Rich  <[EMAIL PROTECTED]> writes:
> > > > I was thinking along the same lines, except at the level of 1%. But
> > > > even at 0.1%, and if we look in the other direction, the "others"
> > > > (...) could also easily be 10 million years _ahead_ of us! (Brings
> > > > us right back to Fermi again-i.e., where are they?)  That
> > > > intelligent civilizations could have started quite early after the
> > > > BBang is supported by the latest studies showing that the earliest
> > > > 1st gen stars in the universe may have been born as early as 200
> > > > million yrs. after the BBang--possibly, even earlier.
> > R> Your viewpoint seems overly simplistic. Consider that the BB
> > R> created mainly hydrogen and helium. Any early stars are likely to
> > R> have only gas giant planets.
> >
> > R> The creation of carbon and other elements heavier than lithium are
> > R> thought to result from supernova explosions.
> >
> > Yes, except that it is also thought that the earliest stars would
> > quite massive, i.e., exactly the kind of stars that undergo supernova
> > explosions.  For instance, there has been a recent detection of CO
> > (carbon monoxide) emission in the galaxy SDSS J114816.64+525150.3.
> > This galaxy is at a redshift of z=6.42, meaning that we are seeing CO
> > molecules when the Universe was only about 1 billion years old (Walter
> > et al.  2003, <URL:http://xxx.lanl.gov/abs/astro-ph/0307410>).
> >
> > The next question is, When did the amount of heavy elements build up
> > to a sufficient amount that planets and intelligent beings could form?
> > We don't yet know the answer to this question, though Mario Livio has
> > speculated that this might have taken a large fraction of the
> > Universe's age.
>
>
> Perhaps in general it might take a significant fraction of the Universe's
> age, but there might have been "pockets" where the build up of
> heavy elements was sufficient very early on?

I know that when a supernova occurs within a dense media (for interstellar
gasses a relatively poor quality vacuum) it compresses the gas and can lead
to a small starburst phenomena. I don't know if one supernova (which can
occur very quickly for a massive star, on the order of hundreds of millions
of years) would be sufficient however.

The dynamics of the timescale are unknown, and I don't think they've been
investigated. But it is clear that the initial population of stars would
be lacking at any rate.

Rich

> Al
>
>
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