From: Charlie Stross (charlie@antipope.org)
Date: Thu May 09 2002 - 06:05:09 MDT
On Wed, May 08, 2002 at 05:58:43PM -0700, Robert J. Bradbury wrote:
>
> What isn't said is that over time there is a decrease in the
> probability of forming stars that will produce hypernovas.
> So the galaxy becomes increasingly safe -- the question becomes
> when it is "safe enough" for life to evolve.
Well, that would actually provide one answer to the big puzzler: why
did the earth support prokaryotes for about 2-3Gy before the eukaryotes
showed up, then only 0.3-0.4Gy before multicellular life took off?
Stephen J. Gould's precambrian evolution engine hypothesis seems to have
taken a beating lately, but if you look at things from a different angle,
a decreasingly frequent series of hypernova events might well explain
why life never got beyond the primitive prokaryotic cells for so long --
then took off in a big way.
-- Charlie
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