ethan@utastro.UUCP (Ethan Vishniac) (08/29/84)
[Go ahead, eat this line.]
This article is a followup to Paul DuBois commenting on Ken Perlow
commenting on Paul Dubois. Rather than repeat their arguments I'm
going to assume everybody has read these articles.
The problem with believing that c, the speed of light, is a function
of time, is, as Ken pointed out, that a constant speed of light is
a basic part of our current ideas about the nature of physics. This
ideas have been subjected to a great deal of experimental testing and
so deserve to be taken seriously. If there were any evidence indicating
that c were, nevertheless, a function of time, then this would cause of
a crises in modern physics. This is not bad, this is exciting. Since
there is no such evidence, we can ignore the possibility.
This leads into a problem in cosmology which people have worried about
in a somewhat different context. To what extent can we be confident
that the laws of physics determined locally apply to the entire
observable universe? The fact that the chemistry of ancient rocks and
the spectra of distant quasars make sense according to these laws
presents us with reasonable reassurance. Theories which involve
changing fundamental constants have to make all the changes at unobservable
epochs in order to be consistent with observations. This leaves the
age and structure of the universe unaffected.
Of course, if you change all fundamental constants together in such a way
as to conceal the change from any observer then you have simply
changed the semantics, not the content, of physics. One could claim
the universe is "really" 6000 years old but physics has changed so that
all our age indicators point to 10 billion years. However, this is
equivalent to saying that any observer present from the beginning would
have recorded the passage of 10 billion years. The date of 6000 years
then becomes a meaningless fiction.
As a general philosophical point, it is worth pointing out that the
fact that scientific conclusions are always tentative does not mean
that all ideas deserve to treated equally seriously. Some ideas
account for our observations in a natural and economical way, some
conflict with observations, and some are consistent with the observations
but do not account for them in an economical way. The first category
of theories deserve to be treated as science, the second do not. The
third category is very very very large. It includes those theories that
we will regard, at some future time, as correct, but only as an infinitesimal
subset. The overwhelming majority are nonsense. "Scientific" creationism
often falls into the second category, depending on whose version you listen
to, but more usually it falls into the third category. This doesn't make
it science. This makes it an unlikely idea about the nature of the universe.
I have serious doubts as whether any version of creationism I have heard
propounded is testable in any sense. If not, this makes it impossible for
it to *ever* move from the third category to the first.
Mentioning it in school as a viable theory would be fair and reasonable only
if we presented it along with a list of other equally, or more, likely
possibilities. To accord them all equal time would require giving
scientific creationism some small fraction of second. This would be fair
to everybody, except the poor students whose time would be wasted.
"Cute signoffs are for Ethan Vishniac
perverts" {charm,ut-sally,ut-ngp,noao}!utastro!ethan
Department of Astronomy
University of Texas
Austin, Texas 78712
P.S - In reviewing the articles submitted over the summer I have the
impression that someone has defended the argument that thermodynamics
forbids evolution on the grounds that the universe as a whole is a
closed system. This is irrelevant. The total entropy of the solar
system ( sun, planets and nearby space) is certainly increasing
regardless of the evolution of life on Earth. Local fluctuations
in entropy are not forbidden by thermodynamics, in fact they are
expected in situations far from equilibrium (that's our planet).