[net.origins] stereoisomers

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