🚀 go-pugleaf

In article <1551@lyman.pppl.gov> Bruce Scott, bscott@lyman.pppl.gov
writes:

>Actually, one important reason why people turned against the exploding
>planet hypothesis was the discovery that certain classes of asteroids
have
>compositions which are not consistent with any scenario which involves
>heating above 300 K. This and the fact that the property classes
>(achondrite, C1 and C2 chondrite, enstatite, etc) are on isotopic grounds
>irreconciliable with any single parent body are the reasons J S Lewis
>argues against it.

I'm going to look into the literature on this soon (I hope) because I have
learned how far behind I've dropped, but tell me why it is necessary to
have debris which has suffered temperatures greater than 300 K to have an 
explosion? There was an explosion in the lab next door to mine at Cal (I
was in 304 LeConte) which had much debris originally at liquid oxygen
temperature which didn't get *up to* 300 K until after the explosion was 
over! I acknowledge that some (probably central) portion of an exploding
planet likely got very hot, but the bulk of the discorporated planet need
not have seen high temperatures, and the parts that had were probably in a
much finer state of division. The mesoscopic fragments, including 
meteorites, need never have seen high temperatures.

I expect that the time scale for the explosion we are speculating about
was much shorter than transport times for heat within the planet. Appeals
to the lack of evidence for heating do not support the rejection of the 
explosion hypothesis.

Leigh