Just before I received this, I was writing a note asking if you had seen
this paper. A couple of comments though,
1) don't you appeal to the equivalence principle to justify *not* including
fictitious forces in physics? (perhaps your last sentence below is an answer
to this question.)
2) (this is from 9 year old memory) I found the paper to be highly
technical, and this is from someone who has some knowledge of 3+1 formalism
in GR. I might add, again if memory serves me correctly, that the
difference between the two frames is more than just observing that the
equivalence over small local regions is similar to epsilon->delta reasoning
in analysis.
I found the paper difficult, but that is a statement about my limitations
and not the principle of equivalence's limitations.
Joel
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From: A. R. Marlow
To: QuistO; RAUBERJ; Phys-L
Subject: Equivalence Principle
Date: Monday, February 16, 1998 10:51PM
Apropos the continuing appeal to the equivalence principle to try to
justify the inclusion of fictitious forces in physics, the clear and
cogent analysis of the principle by Edward A. Desloge (Nonequivalence of a
uniformly accelerating reference frame and a frame at rest in a uniform
gravitational field, Am. J. Phys., 57, 12, December, 1989, Pp. 1121 -
1125) should definitely be read by anyone interested in the issue. The
author shows that it is always possible in principle to distinguish
whether one is in an elevator in a uniform gravitational field or in an
elevator uniformly accelerating in a zero gravitational field, and this no
matter how small the region occupied by the elevator is. It is only when
one restricts the accuracy of the measurements permitted in the elevator
that the two cases can seem approximately equivalent; the author points
out (with references supplied) that, of course, Einstein never claimed
more for the principle, and clearly recognized its approximate nature.
The new emphasis in the paper is on the fact that *uniform* gravitational
fields both exist (contrary to claims made sometimes) and can be
distinguished from acceleration in a field free space. How such an
approximate equivalence can be used to justify inclusion of fictitious
forces in physics has always been beyond my understanding, so I won't try
to discuss that.