From: Charlie Stross (charlie@antipope.org)
Date: Thu Nov 25 1999 - 06:50:47 MST
On Wed, Nov 24, 1999 at 03:03:35AM -0800, Liam. A. Chu wrote:
>
> If it takes two supernovae to get (e.g.) Fe through U, maybe we _are_ the
> Elder Gods, such as there are. 4 Billion + 4 Billion + 4.5 Billion adds up
> about right, in Fermi number terms.
Interesting corollary:
Heterocyclic carbon chemistry really doesn't get on well with elements
from the second transition metal series (or indeed most elements heavier
than iron). Sure there are a few enzymes that use vanadium or iron, but
in general heavy ions with lots of holes in their outer orbitals wreak
havoc on hydrogen bonds.
As successive generations of nucleosynthesis increases the proportion of
things like lead and uranium in the mix from which planetary systems
are formed, can we anticipate the closure of the "window" within which
terrestrial planets provide conditions suitable for the evolution
of carbon-chemistry based life? So we may not only be nearly the first
kids off the starting block, but not that far from the last generation
before the neighbourhood turns into a toxic waste dump.
-- Charlie
(delurking for once)
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