[ExI] Double-Earth (Was: kepler study says 8.8e9 earthlike planets)

[Anders Sandberg]

On 2013-11-25 15:23, spike wrote:
>
> >...There are other expanding liquids like beryllium difluoride, but most 
> are elements like silicon, bismuth, antimony, gallium and plutonium...
>
> Ja.  I can't think of any life forms that depend on that oddball 
> characteristic of water ice.  Perhaps the remarkable thing here is 
> that with all the ice on this planet, there are no known (to me) life 
> forms that use it in its solid phase.  One would think there would be 
> a snow eater somewhere.  Clearly it wouldn't be to extract energy from 
> the water (ground state compound) but rather some kind of life form 
> that can plant itself in snow and use sunlight.
>

There are algae that thrive not just on or under sea-ice, but in it: 
http://www.arctic.noaa.gov/essay_krembsdeming.html
Also, some animals have adapted to freezing in order to (I assume) get a 
first shot at good locations: 
http://science.whoi.edu/labs/pinedalab/Subpages/larvaeinice.html

But note that they do not eat snow - it would need to provide so much 
energy per volume eaten that it counteracts the energy required to melt 
it, and that is a pretty tall order.


> >... Even I agree that a planet with plutonium oceans is unlikely to be 
> habitable for life. -- Dr Anders Sandberg
>
> I learned a new thing by thinking about this.  There is an isotope of 
> plutonium which is non-fissile, 244.  Get a sphere of the stuff, heat 
> it to 900 and some Kelvin, you have an ocean of plutonium, with 
> radioactive particles up the kazoo but no fission.  Until Anders' 
> offhanded comment about an ocean of plutonium, I never knew there was 
> such a critter.  Ain't science kewallll?  {8-]
>

Sounds like a great practical joke to do when re-engineering a solar 
system. A hot ecology based on plutonium as a solvent for some weird 
metal-oxide biochemistry/mechanochemistry.



-- 
Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University

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