[ExI] Collapse of the universe is closer than ever before

[BillK]

On Fri, Dec 13, 2013 at 10:52 PM, Anders Sandberg  wrote:
> Already dealt with :-) :
> http://www.aleph.se/andart/archives/2013/12/dont_fear_the_vacuum_reaper.html
>
>

I have a couple of queries re the two papers you reference on your web
site, generated from the comments in the Nature article.
<http://www.nature.com/news/life-possible-in-the-early-universe-1.14341>

First query is that the time scales on the two papers don't seem to match up.

'Planets in the early universe' is talking about the period over 400
million years after the Big Bang, when the first stars started up.
See: <http://www.solstation.com/x-objects/timelin2.jpg>

'Life possible in the early universe' is talking about the period
around 15 million years after the Big Bang when the afterglow of the
Big Bang had cooled down to around 300 Kelvin. The writer is
speculating that even this early in creation there appeared pockets of
dense matter sufficient to form very early stars and rocky planets.
This sounds like a big stretch to me and involves some rewriting of
the current view of the early universe.

>From the comments:
I do wonder what the 'rocky planets' would have come from and been
made of given that the content of the Universe at a few million years
old was basically hydrogen, helium, deuterium plus vanishingly small
tiny amounts of slightly heavier elements. Complex chemistry requires
chemical elements, which only exist because generations of stars have
undergone catastrophic fusion and explosion as supernovae to spread
their heavy elements out into space where they can slowly re-form into
planets. Loeb needs some special pleading to argue that enough stars
could even have formed and gone supernova that early...
--------------

My second query, also from the comments, is that the temperature was
only suitable for a brief 2 to 3 million years. This short a time
scale is not enough to create 'life'. Before the first supernovae, you
wouldn't even get precursor chemicals.


BillK