[extropy-chat] Nuke 'em

Robert J. Bradbury bradbury at aeiveos.com
Tue Oct 25 17:20:53 UTC 2005

On Mon, 24 Oct 2005, Acy James Stapp wrote:

> Most plants are CO2 limited.
> http://listserv.repp.org/pipermail/gasification/2004-January/000546.html

You have to be careful with this.  Obviously to raise the CO2 to 600 ppm,
they had to enclose the plants in something.  It isn't clear whether that
something had a UV shielding effect.  If they were using artificial light
then it wasn't a "real world" test.  I suspect a non-trivial amount of
energy goes into generating UV absorbing molecules and recycling molecules
damaged by UV-B & UV-C radiation and repairing the DNA damage caused by
natural sunlight.  Ideally one wants solar ponds where the top-most cell
layer(s) do nothing but absorb UV-B and UV-C radiation and the layers below
can focus on picking of photons of specific energies and not worry about UV
damage (readers of Nanosystems will note that this is not too different from
Drexler's suggestion of coating nanomachinery with a thin layer of aluminium
to protect it from UV radiation).

*Now*, if you could develop solar cells (or bacteria) that could effectively
harvest and use the UV photons you would have a significant advantage over
current plant (chlorophyll) based systems.


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