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

From: Charles Hixson (charleshixsn@earthlink.net)
Date: Tue Dec 16 2008 - 14:15:02 MST


Alexei Turchin wrote:
> There is a big difference between exposive detonation which could take
> seconds, and constant burning like in stars. Only in the second case
> you need high mass to keep reacting matter under sufficient pressure.
>
> In case of detonation we have supersonic fire - which means that
> bowel of Jupiter will have no time to adjust to the chaging
> temperature and pressure.
>
> Of couse Jupiter can''t burn constantly like a star. It could only
> explode - and this explosion would lead to human extinction.
>
> On 12/9/08, Krekoski Ross <rosskrekoski@gmail.com> wrote:
>
>> Jupiter lacks the sufficient mass to sustain a fusion reaction by
>> approximately 2 orders of magnitude.
>> Theres a reason why we find brown dwarf stars with masses over 60 times
>> Jupiter.
>>
>>
>>
>>
>> On Tue, Dec 9, 2008 at 8:04 PM, Alexei Turchin <alexeiturchin@gmail.com>
>> wrote:
>>
>>> 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
>>>>
>>>>
>>
>
>
I think you need a more detailed model. Even were there a pocket of
Jupiter in which Deuterium were sufficiently concentrated, that wouldn't
apply to *most* of the planet. So even were that pocket to be ignited,
it wouldn't cause the planet to explode, but only that one small
pocket. (Even so, I doubt that the pocket could be exploded. Fusion
reactions generally require pressure and heat as well as the proper
ingredients.)

You should probably pick something else to worry about...or as a hook on
which to hang your story. MacroLife (George Zebrowski) did something
analogous using an "artificial metal", which is irrefutable as nobody
knows what the characteristics of said "artificial metal" would be. But
I don't think that a planetary explosion based on Deuterium is plausible
enough for a story. I'd put the odds at less than 1 in a google but
greater than 1 in a googleplex per intentional attempt. This, however,
isn't based on calculation, but just because I don't want to say that
it's flatly impossible. (You could possibly increase the odds, but
you'd need to appeal to either extremely large engineering works of a
peculiar nature [a Deuterium mine that encircled the planet?] or some
future discovery in physics. And it would probably still be
unreasonably improbable.)

Try orbital instabilities of the giant planets causing them to collide
in such a way that they dropped into the sun, hitting the Earth on the
way. That's not nearly as fast, but it's more plausible (i.e., not
very), and would be extremely difficult to do anything about. Or
re-read "When Worlds Collide" by Balmer and Wylie. (1930's Science
Fiction, but reasonable enough that a major rewrite could update it.)



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