Since I am not any sort of physicist, I'll go ahead and ask one more stupid
question. I see by my CRC that deuterium makes up 0.15% (or was it 0.015%)
of hydrogen on Earth. Is there any reason to believe that this represents
a universal distributrion of the stuff? I realize full well that I am not
going to find a gas giant with a pure deuterium atmosphere, but what about one
with twice the universal average? What limits would be reasonable?
I saw a note in some book review recently where the reviewer thought that
identifying objects' planets of origin by the isotope ratios of various
elements was a nifty idea. He apparently hadn't read some of the things I have;
such as the proceedings of a 1970 conference on metallurgy applied to ancient
numismatics, where it is noted that it is apparently quite feasible to identify
which mines silver came from by the distribution of the isotopes of the trace
amounts of lead remaining after refining. Of course, if you melt down lead
from several different mines in one lump, you can no longer identify it that
way. (So if you needed an untraceable object, all you would need to do would
be to combine raw materials from two or three places.)
Rob Dean