Theoretical physics often involves idealization - massless
strings, frictionless planes, perfectly spherical planets, &c. This is a
matter of approximation, & it's really something of an art to know what
to include & what to leave out. The trick is to include only what's
"important" - i.e., can describe something observable.
We do this because we're trying to find general laws. I.e., we
don't want just a description of what happens when Galileo slides a
block down an inclined plane in Florence c.1600 a.d., but what happens
with inclined planes _in general_ - & then with falling & moving bodies
in general. That means we're leaving out the peculiar characteristics
of G's inclined plane experiments. We can then try to take account of
those peculiarities - friction of his particular apparatus, atmospheric
conditions on that day, G's possible subconscious biases starting &
stopping each run, &c.
The contingency of actual events shows up in chaos theory. The
idea that we can know initial conditions for something like the earth's
atmosphere is an idealization. We know now that in some systems like
the atmosphere, slight changes in those conditions - far below our power
of observation - can make a big difference in the way the weather
develops. So while we can learn & predict some features of weather in
general, each hurricane, tornado, &c is unique.
The rise of science & the Enlightenment led to belief that only
the _general_ features of nature & history could tell us anything about
the ultimate ground of reality - i.e., God. (E.g., Lessing) In this
view, the basic laws which underly all atmmospheric phenomena might tell
us something about God ("God is a mathematician"), the specific
interaction of wind & water which made it possible for a group of Hebrew
slaves to escape from Egypt couldn't.
On the contrary - without denying that God is involved in the
general laws of the world, God's revelation, & thus our knowledge of who
God is, comes in contingent happenings in the world - most importantly,
the Exodus & the death & resurrection of Jesus.
Further, God is involved in the contingency of "ordinary" events
- growth of plants for food, &c. Quantum theory & chaos show that God
_can_ be so involved without being bound to a specific course of events.
I.e., God has freedom to act without "violating" the general pattern of
nature.
On an even more basic level, even the general laws of nature are
contingent - i.e., they could have been different, & have been chosen
freely by God. (Cf. Torrance's "doctrine of the contingent rationality
of the universe.)
George L. Murphy
gmurphy@imperium.net
http://www.imperium.net/~gmurphy