dmr@grigg.UUCP (12/05/84)
Hmmm, and all this time I had thought that L stereoisomers rotated polarized light to the left, and D to the right. That is, the labels are not arbitrary with respect to particular chemicals, only in the original choice of sign. An article in Nature about 6 weeks ago proposed an explanation for the preponderance of L-amino acids in living forms. It calculates a small effect from the (non parity-conserving) weak force that would make the L forms more favorable energetically. I found it less than completely convincing. (The energy differential was, at most, about 1 part in 1e-17). By the way, thanks to Ray Miller for posting the SOR papers. Many people have wanted to know what creationists actually believe, and these remarkable documents certainly tell us. Dennis Ritchie
friesen@psivax.UUCP (Stanley Friesen) (12/06/84)
In article <1066@grigg.UUCP> dmr@grigg.UUCP writes: >An article in Nature about 6 weeks ago proposed an explanation >for the preponderance of L-amino acids in living forms. >It calculates a small effect from the (non parity-conserving) >weak force that would make the L forms more favorable energetically. >I found it less than completely convincing. (The energy differential >was, at most, about 1 part in 1e-17). Biologists have had another explanation for a number of years. It is known that clay-surface-layer catalysis is capable of generating polarized organic compounds. Considering that clay particles would have been present almost as long as the Earth, I think this is quite adequate as an explanation. The basic fallacy of this creationists' approach is the implicit assumption that an incomplete explanation is inadequate, and that unknown *details* invalidate the entire concept. If this were so *all* scientifiec theories would be invalid, since *none* is complete, and all include "I don't know"s. -- Sarima (Stanley Friesen) (ucbvax!hplabs!sdcrdcf!psivax!friesen)
josh@v1.UUCP (Josh Knight) (12/09/84)
> I found it less than completely convincing. (The energy differential > was, at most, about 1 part in 1e-17). Presumably 1 part in 1e17 was intended. Josh Knight, IBM T.J. Watson Research josh at YKTVMX on BITNET, josh.yktvmx.ibm on CSnet, ...!philabs!v1!josh