At 06:55 AM 8/1/2004, you wrote: >On 31 Jul, . <yerushabel@xxxxxxxxx> wrote: > > As Moller's text on Relativity makes clear, the centrifugal, Coriolis > > and Eulerian forces which are treated as fictitious forces in a > > non-geocentric context are real, actual forces in a geocentric context. > > No they're not real. They seem to be real if you're in a rotating >environment, but they don't actually exist. In general relativity, even gravity is fictitious. General relativity allows non-inertial frames of reference, even earth-centered earth-fixed. Here's a quote from Einstein: "The struggle, so violent in the early days of science, between the views of Ptolemy and Copernicus would then be quite meaningless. Either CS could be used with equal justification. The two sentences, 'the sun is at rest and the earth moves,' or 'the sun moves and the earth is at rest,' would simply mean two different conventions concerning two different CS." -- Einstein and Infeld, The Evolution of Physics, p.212 (p.248 in original 1938 ed.) CS, in that quote, means Coordinate System, and here's another from Einstein's Theory of Relativity by Max Born. From page 356 of the 1962 Dover edition: "A similar error lies at the root of the following, which is continually being brought forward, although the explanation is very simple. "According to the general theory of relativity, a coordinate system which is rotating with respect to the fixed stars (i.e., which is rigidly connected with the earth) is fully equivalent to a system which is at rest with respect to the fixed stars. In such a system, however, the fixed stars themselves acquire enormous velocities." Born does provide the simple explanation promised. In the Earth-fixed system, the metric coefficients are transformed, becoming very large at large distances away from the Earth. Since the limit on the speed of light is derived from these coefficients, the "enormous velocities" of the stars are still less than their local speed of light. Nowadays, the interpretation is different. At any place, one can find a local frame of reference that can be aligned so as to be inertial--and in *that* local frame, the local speed of light is c. So, it is often said that even in general relativity, the speed of light is restricted to c--but you can see that the interpretations are a bit different.