Re: [sl4] giant planets ignation - one more existential risk

From: Alexei Turchin (alexeiturchin@gmail.com)
Date: Tue Dec 09 2008 - 05:04:54 MST


This estimation is my one prior subjective probabilities.

I spoke about artificial ignition of Jupiter by man - that is by use
of some kind of fuse like nuclear bomb, which does not exist in nature
- so past records will not give us any information.

But my conclusion is based oh 3 facts:

1) Scientific article that estimate that termonuclear detonation of
deiterium is possible if its concentration is higer then 1 to 300.
"Necessary conditions for the initiation and propagation of nuclear
detonation waves in plane atmospheres". Tomas Weaver and A. Wood,
Physical review 20 1 Jule 1979,
http://www.lhcdefense.org/pdf/LHC%20-%20Sancho%20v.%20Doe%20-%20Atmosphere%20Ignition%20-%202%20-%20Wood_AtmIgnition-1.pdf

2) Mesurements of deiterium concentration in the atmosphere of
Jupiter, which is 1 to 1600 ( but other mesurement gave much lower
value), that is only 5 (five) times below critical level.
Hubble observations and lowering probe to Jupiter: Hubble measures
deuterium on Jupiter - Hubble Space Telescope
http://findarticles.com/p/articles/mi_m1200/is_n14_v150/ai_18757250

3) The fact that deiterium is very prone to isotopic separation in
natural processes, which means that its concentration may be much
higher in the bowel of Jupiter, or other planet.
e.g. see: "In contrast, Uranus and Neptune may have been enriched in
deuterium, during their formation, by the mixing of their atmospheres
with comparatively larger cores containing D-rich icy grains".
http://herschel.esac.esa.int/Publ/2001/lellouche.pdf
Emmanuel Lellouch. Observations of planetary and satellite atmospheres
and surfaces

So I find very plausible that somewhere in the Solar System
concentratiopn of deiterium is enogh for termonuclear detonation, but
I underatsn that my conclusion may have errors, so I lowered it from
100 per cent to 1 per cent.

On 12/9/08, Stuart Armstrong <dragondreaming@googlemail.com> wrote:
> >> I estimate that probability of teoretical possibility of ignition of
> >> giant planet is arround 1 per cent.
> >
> > Over what period of time? And how come it hasn't happened yet --
> > Jupiter's been there for billions of years without igniting.
>
>
> A narrow aplication of the anthropic principle gets rid of the
> argument that we shouldn't worry about whether its happened yet or not
> - if life evolves anywhere, it would have to evolve in a solar system
> where the gas giants don't periodically go nuclear.
>
> But I second the question about how these probabilities are arrived
> at, and over what period of time - and add, what is the astronomical
> evidence? Gas giants igniting should be the kind of signal that can be
> detected over large distances.
>
>
> Stuart
>



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