[meteorite-list] Earths core

[stan .]

>Well, Half life can't change (otherwise the universe would be in a real 
>mess) but who knows what effect very very high pressure, heat and 
>gravitational force would have on a fission reaction, maybe at the earths 
>core, a nuclear reaction happens at an accelerated rate due to the much 
>higher pressures (i.e the atoms are forced much closer together, and there 
>would be total neutron absorbtion) or maybe even hot fusion? This would 
>result in the radioisotopes transmuting into Lead and Iron etc a lot faster 
>than they would under natural decay.


fusion isn to going to be possible in the earth's core- tempertures are off 
by several orders of magnitude..

fission reactions arent affected by high pressure, heat or gravity (within 
sensible limits). as the earth's core is under tremendous pressure it's 
density is increased, so the criticle mass of uranium is correspondingly 
lowered, making it easier for a blob of uranium to undergo a fission chain 
reaction. this sint going to 'transmute radioisotopse into lead and iron' 
any faster however, since the timespan of the radioactive decay chain is 
unchanged.

also, if we were to find a hunk of a heavy (density wise) element iron 
meteorite, remeber that it would ahve to come from the core of a body large 
enough to differentiate to a similar extent as the earth (per your original 
question). i dont know if there are any asteroids out there that sample 
hundreds if not thousands of miles inside of what used to be a large body.

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