ethan@utastro.UUCP (Ethan Vishniac) (10/30/84)
[This space reserved for obscenities]
Our system isn't saving news articles for more than a
few weeks. As a result I no longer have access to Larry Bickford's
last three articles. This is too bad because I have lot to say
about them and wanted to quote them exactly. I'll have to rely
on my memory instead. Fortunately several other people have been
responding. I particulary liked Patrick Wyant's article.
First, I note with amusement that Larry felt peeved enough
by my summary of creationism (which read something like: "God
created the world 6000 years ago. All indications to the contrary
are his idea of a joke.") to comment that I must be a <censored>.
The word he was looking for is "skeptic". It's clear why he regards
this as an obscenity. Second, the list of alternative possibilities
that mix supernatural explanations with science was not meant to
be exhaustive. Even so I found it revealing that Larry Bickford
chose to ignore the suggestion the a creator might have made
life at some early point in the history of the Earth and subsequently
let it evolve. This suggestion is not science (nor do I take it
seriously) but far from being a "poor stepchild" of evolution and
creationism it is demonstrably better than standard creationism in
that it does not require any ad hoc explanations for the evidence
regarding the evolution of life on Earth.
The issues of radiometric dating and the necessity for completeness
in a scientific model have been adequately dealt with by others.
Let me just make a brief comment about continental drift. The
comments I made in a previous posting were not meant to be a "proof"
in a geometrical sense, but a summary with an invitation for the
creationists to point at the specific parts they found objectionable.
The relevance of this is that current ideas about continental drift
make locally complicated strata inevitable. Larry Bickford kindly
responded by objecting at two points. First, he questioned whether
the continental motions were persistent. Second, he suggested that
if they were then the continents would move in a straight line across
the globe i.e. not colliding "repeatedly" but exactly once. The first
point is legitimate. The answer is that the near term persistence of these
motions is revealed in the presence of intense geological activity
(including the presence of geologically young mountain chains)
along lines where there is convergent motion. Along lines where
there is divergent motion we see the age of rocks is well-correlated
with their distance from the rift. This shows that the rift has been
spreading steadily, with new rock solidifying in the center, for
significantly long periods of time. The second point is a little
bizarre. The only mechanism for moving the continents that is physically
reasonable is pressure from convection currents in the mantle. The
existence of such plumes is shown by the appearance of hot spots in
the crust that produce volcano chains as the plates move over them
(e.g. the Hawaian Islands - Midway Islands chain). Such plumes will
not be arbitrarily stable (watch a boiling pot someday). The exact
history of continental collisions can be reconstructed not just by
trying to fit continental plates together, but by a detailed comparison
of the geological structure of the plates. This detailed comparison
shows a much more convincing "fit" than the coastlines which originally
inspired the theory.
One last note, Larry Bickford is *very* peeved because I (and others)
refuse to make any distinction between creationism and biblical creationism.
I don't think that any such distinction is valid. Both are supernatural
belief systems. The former is a subset of the other, but the dividing
line appears entirely arbitrary. I am, however, willing to compromise.
Larry Bickford often notes that it has "so far" been possible to maintain
consistency between the two. If he can tell me any realistically possible
experiment which will lead him to reject that consistency then I will
remember to clearly distinguish between the two. Furthermore, if he
can present any way in which "scientific" creationism is falsifiable
I might even stop putting quotes around the word scientific.
"I can't help it if my Ethan Vishniac
knee jerks" {charm,ut-sally,ut-ngp,noao}!utastro!ethan
Department of Astronomy
University of Texas
Austin, Texas 78712