[From Bruce Gregory (960520.1100 EDT)]
(Chris Kitzke 960517.1705 EST)
Example: with no theory and only observation, I could
reasonably argue that the sun revolves around the earth. Am I
making sense here?
Very apt example. One of the first things we confront precollege
science teachers with is that the fact that they believe the earth
orbits the sun, but they have no evidence to support this belief.
(There is evidence, but it is quite subtle because the stars are at
such vast distances. Otherwise we could see the motion of the earth
reflected in the motion of the stars. It takes very stable
equipment and considerable effort to observe the latter effect.) As
you say, we believe in a sun centered system because we have
dynamical theories (Newton's and then Einstein's) which allow us to
model this behavior, but no theory that allows us to model an earth-
centered solar system and still be consistent with the rest of
physics.
Bruce G.