I have always taken the standard tests of general relativity (bending of light at the sun's limb, exact precession of the orbit of Mercury, slowing of the orbits of binary stars by gravitational radiation) as 'good' tests of the theory. I'm reading a set of essays by S. Chandrasekhar, however, and in "The Aesthetic Base of the General Theory of Relativity" the author writes:
"But all these effects relate to departures from the predictions of the Newtonian theory by a few parts in a million, and of no more than three or four parameters in a post-Newtonian expansion of the Einstein field-equations...Should one not argue that a confirmation of a theory, which generalizes a theory as well tested in its domain of validity as the Newtonian theory, should refer to predictions which relate to major aspects of the theory, rather than to small first-order departures from the theory which it replaces?"
Chandrasekhar goes on to argue that one possible reason GR is nevertheless taken very seriously is that "...it does not not violate the laws of other branches of physics not contemplated in its formulation, such as thermodynamics or quantum theory..." and therefore it meshes exceptionally well with known physics.
I'm curious what you genius astrophysicists make of this, especially the observation that current best tests of GR do not address deep aspects of the theory. (Rather than debating GR itself I'm more interested in the meta-question of whether, as theories become more subtle (and presumeably more accurate), it necessarily becomes harder to test their deep aspects or at their limiting conditions.)
[Late note: I do not by any stretch do Chandrasekhar's essay justice in these excerpts; he makes many excellent points that I don't mention. This essay and some others of Chandrasekhar's are collected in Truth and Beauty, 1987, University of Chicago Press]
<font size=-1>[ This Message was edited by: DStahl on 2002-02-02 15:51 ]</font>