[ExI] woooohoooo! it's ice!

[Amara Graps]

Robert Bradbury:
>Small pieces of bright material can "vanish" if the Martians are
>stealing them.  What if they are diamonds or sapphires for example?
>This is one complaint I'll always come back to with well trained,
>otherwise very good scientists, they have a lack of imagination.

Funny you should mention diamonds. When Eugene posted the news
item

"Diamonds on Demand"
http://postbiota.org/pipermail/tt/2008-June/003149.html

on Transhumantech, recently, I was thinking that surely the planetary
geochemists would easily know how to distinguish between those amazing
synthetic diamonds described in the article and those created in the
Earth's interior.

Diamonds have two important roles for geochemists: 1) they can date
samples of the Earth's ancient mantle and 2) they hold original mantle
noble gases retained at the time of their crystallization [1]. Of the
first, radiometric dates so far show Precambrian ages, some being older
than 3 Ga.  Of the second, since diamonds crystallized in the mantle at
temperatures likely to exceed 1000 deg C and have resided there for a
substantial time, and since the heavier-than-helium noble gases have low
diffusion in diamond coefficients, the gases are likely representative
of the mantle at the time of formation. Xenon and neon are two noble
gases that are particularly well sampled in diamonds and provide
valuable boundary conditions for models of terrestrial planetary
formation [2].

These diamonds-with-embedded-noble-gases played a large part in in a
fiction story I wrote last year about posthumans living one million
years in the future. The solar system didn't change very much in one
million years, but humans changed alot; in my story most of them had
exited the solar system long before. But a few sentimental posthumans
remained behind, who were sufficiently modified to live comfortably in
underground cities on tethered and untethered cubewanos in the Kuiper
Belt. My main character was an archeologist who studied the departure of
the posthuman exodus by studying archeological sites of ancient markets
on the path of stepping stones of plutinos, centaurs, cubewanos, and
other assorted distant rocks, which became the posthumans' route out of
the solar system, in their journey to the stars. I called the path of
stepping stones 'The Diamond Road' because the ancient markets revealed
significant stashes of diamonds-with-embedded-noble-gases. These
diamonds were not formed inside of the Earth, however, they were formed
in other small Vesta-like bodies in the outer solar system where the
formation conditions were just right. These markets had to be a trade
route for the ancient posthumans because those diamonds with their
stores of noble gases were a precious traded commodity which provided
health benefits to the posthumans who wore the diamonds inside of
their skin.

This story demonstrated the opposite of lack of imagination, in fact so
much imagination, that I didn't take seriously (enough) the publication
editor's (D.B.s' editor) requirement that my story should be an essay,
not a story, and it was booted out of the collection of essays because
it didn't follow the format of the rest of the book. As Sean Carroll
told me after: "that's what I get for being too original".

Amara

References

[1] Ozima, M. and Podosek, F.A., _Noble Gas Geochemistry_, Cambridge University
Press, 2002, pg. 165-166.

[2] ibid. pg. 96-97




-- 

Amara Graps, PhD      www.amara.com
Research Scientist, Southwest Research Institute (SwRI), Boulder, Colorado