[FoRK] SETI and the Cosmic Quarantine Hypothesis
Mon Oct 24 09:23:40 PDT 2005
At 19:05 -0700 on 10/23/05, J. Andrew Rogers wrote:
>My formerly strong chemistry background has atrophied beyond recognition,
>but I believe the important difference between carbon and silicon is that
>carbon has a much simpler and stronger electron structure, lacking the outer
>d-orbitals that silicon has, making it a more robust building block for
>complex molecular structures. That the chemistry of life is overwhelming
>biased toward p-orbital elements despite no shortage of d-orbital elements
>in our environment is not likely to be an accident.
>Electron orbital structures explain quite a bit about a lot of things, but
>most people forget them as soon as they are taught them. Magnetism in
>materials, for example, is all about spin alignment in orbital shells.
Yes! That's what I was trying to remember... My big problem with
the "silicon based life" meme is that their is no evidence in nature
or the lab that silicon can replace carbon in very large molecules
(i.e. proteins). It's a cute "how could life be different?" answer,
but I don't see how it could happen in our universe.
Arguing with an engineer is like wrestling with a pig in mud.
After a while, you realize the pig is enjoying it.
Kevin Elliott <mailto:kelliott at mac.com>
AIM/iChatAV: kelliott at mac.com (video chat available)
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