sci.physics.particle

On Feb 25, 10:03=A0pm, pmb wrote:
> On Feb 25, 2:24=A0pm, "Paul B. Andersen"
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> <...@> wrote:
> > Juan R. Gonz=E1lez-=C1lvarez skrev:
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> > > Tom Roberts wrote on Mon, 25 Feb 2008 15:47:04 +0000:
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> > >> The best model we have for the propagation of light near a massive
>
> > > no.
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> > >> object like the sun is GR, in which the curvature of spacetime is the=

> > >> important aspect in determining the path light follows. And it agrees=

> > >> with measurements to part-per-million accuracy over an enormous range=
.
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> > > Theories without spacetime curvature also agree with that.
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> > Could you name one of those theories, please?
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> Personally I know of no such theories. However spacetime curvature is
> not neccesary for light deflection in a gravitational field. So long
> is there is a gravitational field present, . non-vanishing
> connection coefficients, then a particle can be deflected. A uniform g-
> field is a perfect example. The spacetime curvature associated with a
> uniform gravitational field is zero and yet a beam of light will be
> deflected. Geometrically speaking the deflection is described as the
> observer corresponding to a frame of reference for which a geodesic
> represents a non-straight line in space, . one changes from
> Minkowski coordinates to "curvilinear" coordinates. Spacetime
> curvature is only neccesary when geodesic deviation is expected.
>
> Pete- Hide quoted text -
>
> - Show quoted text -

Hi Pete

I remember Kip Thorne commenting, in his non-mathematical book on the
history of gravitational physics, that he occasionally liked to use
teleparallel gravity to evaluate gravitational wave phenomena.
Teleparallelism is a GR equivalent.

/wiki/Teleparallelism

Bruce