Geocentrism and other issues

Gordon Simons (simons@stat.unc.edu)
Sat, 7 Oct 1995 11:16:38 -0400 (EDT)

Abstract: I comment on John Turnbull's recent posting on geocentrism,
Glenn's response to same, and attempt to relate this, and recent
discussions on geocentrism, to questions of scientific vs. theological
explanations, and to the TE vs. PC debate.

I would like to thank John Turnbull for a very interesting maiden
contribution to the reflector.

John says he's not a geocentrist, nor am I, but then goes on to point out
that "Decisive refutation of geocentricity is not as obvious as it may
seem," which he explains in some detail. Some of the salient features are:

1. "Planning a trip to the moon CAN be done with a geocentric model";
"Ernst Mach worked out the physics as to how it could be done."

2. The usual interpretation of the Michelson-Morley experiment, that there
is no ether, is not essential and can be replaced by an interpretation
that our speed with respect to an ether is zero.

3. "Russel Humphreys has written a book recently titled _Starlight and Time_.
Russ has proposed an intriguing explanation of how it is possible for us
to observe stars billions of light years away on an earth not more than a
few tens of thousands of years old."

4. In formulating his "general relativity", Einstein chose one of two
"meaningful models", a "finite and unbounded", non-"anthropocentric"
model over a "finite and bounded", "anthropocentric" model (used by
Humphreys). The latter places us at or near the center of the universe.

5. The two models are not observationally equivalent. The latter
describes a universe in which starlight is observationally uniformly
distributed at the center, and skewed toward the center for observers near
the edge.

John suggests that the finite-and-bounded model should appeal to theists,
and, in particular, to Christians - because of its anthropocentric bias.

I will attempt some comments:

a) There is an important difference between two "equivalent models" (such
as I have been discussing in my earlier postings on geocentrism), which
explain the same data in two equivalent ways, and two "NONequivalent
models (such as the finite-and-unbounded and finite-and-bounded models),
which predict different types of data.

b) If no life exists outside the confines of the earth, then under the
finite-and-bounded model all possible observers would be in the center of
the universe, where (I gather from John's comments) no observational
difference between the two models can be seen. If so, there WOULD be a
sense in which one could properly view the two models as "observationally
equivalent" - from a human perspective.

c) When, in point 3 above, John states "it is possible for us to observe
stars billions of light years away on an earth not more than a few tens of
thousands of years old," I gather that he is mixing the two models.
Presumably, the stars that are "billion of light years away" refers to
the finite-and-unbounded model (the one that holds sway today), and the "a
few tens of thousand years old" refers to the finite-and-bounded model.

d) Glenn, when referring to John's posting, asserts:
"The motion of the earth around the sun prevents the earth from occupying
the exact center (of) such a universe. The motion of the sun around the
galaxy prevents the sun from occupying the exact center of such a universe
and the motion of the galaxy in the local cluster prevents the galaxy from
occupying the preferred center exactly."

I don't agree. These arguments merely reflect the viewpoint of the
standard physical models of the universe. See point 2 above. Under the
finite-and-bounded model, as I understand things, a geocentric view can
still be sustained.

e) I believe what we are discussing here has other ramifications:

(i) Terry Gray has pointed out for us the importance of "primary" and
"secondary" explanations of scientific phenomenon. Both look at the same
data. The first explains it as God's activity, the latter from a
naturalistic perspective. Terry argues that both explanations (Might I use
the word "models?") explain the data - but in different ways. This is an
interesting and intriguing parallel to what John has described.

(ii) Loren Haarsma, with Brian Harper agreeing, (I hope I have the name
order right.) asserts:
"The difference between 'deistic' and 'theistic' evolution, as I have
defined them, is almost entirely one of theological perspective rather
than scientific interpretation. I think that the definition of 'deistic
evolution' may be within the bounds of orthodox understandings of God's
governance of nature -- albeit barely within the bounds -- so long as you
add God's guidance and intervention once humanity arises."

Are these two semi-equivalent models that "explain" the same data, with
different theological interpretations? It seems so.

In this regard, Brian adds to his commentary the remark:
"From a theological point of view, the main point for me is 'mindful
intention' (as Howard would probably put it)."

<iii> I wonder whether something similar is going on in the debate
between the TE and PC positions:
We in the reflector tend to think in terms of one acceptable description
of reality - and view ideas that sound different as fundamentally
different. Is this really the case? For instance, when Glenn is insisting
on a TE model and Stephen a PC model for describing and interpreting a
piece of data, is it possible that both are correct - in that no amount of
effort is going to demonstrate that one view is correct and the other is
wrong? Sounds weird, doesn't it? But how weird is this?

Finally, I would like to thank Bill Hamilton for a series of private
e-mail communications on geocentrism, which have contributed to the present
posting.

Gordie