[extropy-chat] Nuke 'em

Damien Sullivan phoenix at ugcs.caltech.edu
Sun Oct 23 19:34:47 UTC 2005

On Sun, Oct 23, 2005 at 02:21:02PM -0500, Damien Broderick wrote:

> >I also don't know if we even have industrial tech
> >for CO2->fuel, and am struck that no one ever talks about it even as a
> >research possibility.  It's oil from coal, or hydrogen from water, never 

> New biotechnology will grow liquid fuel for the poor, according to Freeman 

Okay not no one, and people do talk about biodiesel... but I said industrial
tech.  You know, suck CO2 out of the air, crack it, crack water, mix to taste.

I went googling for [phytoplankton photosynthetic efficiency] and didn't find
useful numbers easily, but did find Bradbury's own page:

"On the basis of these limitations [visible light, and quantum stuff related
to working with carbon atoms], the theoretical maximum efficiency of
solar energy conversion is approximately 11% [hey, my estimate!]. In practice,
however, the magnitude of photosynthetic efficiency observed in the field, is
further decreased by factors such as poor absorption of sunlight due to its
reflection, respiration requirements of photosynthesis [looks like CO2] and
the need for optimal solar radiation levels. The net result being an overall
photosynthetic efficiency of between 3 and 6% of total solar radiation. } "

Colinvaux also noted that the fractal nature of bushes and trees is consistent
with the plant needing respiratory area more than light area, and with working
well in diffuse light.  If light were the sole concern a flat sheet of green
might work better than all those buried leaves.

-xx- Damien X-) 

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