[ExI] powers of ten

[John Clark]

On Tue, Jan 27, 2015 at 2:20 PM, spike <spike66 at att.net> wrote:

>
> >> Yes, I am surprised that rocky planets could form only 3 bullion years
>> after the Big Bang.
>
>  >Indeed?  The early universe would have had plenty of type 1A supernovae
> near the core of a galaxy.
>

Perhaps, but I  have a hunch type 2 supernovae might be a better bet. Even
trace amounts of metals can have a substantial effect on star formation (it
makes for smaller stars) and metals cause big stars to loose a lot of their
mass due to solar wind, but obviously the first generation of stars would
have no metals so they would be bigger and would retain more of their mass
than stars do today.

The lifetime of a star is inversely proportional to the square of its mass
so the first stars wouldn't have lasted long and would soon go out with a
bang. Type 1A supernovae come from 2 smaller (although still larger than
our sun) stars in close orbit around each other, and I think their life
cycle would be longer than the very massive sort of star that could produce
a type 2.

But even so I was surprised there were enough heavy elements around that
early to form a planet, nevertheless I still think rocky planet formation
must have been less common 11 billion years ado than it was 4.5 billion
years ago when the Earth was formed.

And I certainly agree this is a great time to be alive.

  John K Clark
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20150127/3057089c/attachment.html>