Re: Does Newtonian gravity bend light?

[Roger Haar <haar@PHYSICS.ARIZONA.EDU>]

Hi,
        Although this business can be a bit sticky and
cause flame wars, I will make a few comments.  My
reference is the little Dover Press book "The
Principle of Relativity" by Einstein and others.
This is a collection of reprints of the original
papers.

        In a paper "On the Influence of Gravitation on
the Propagation of Light," Annalen der Physik,
35,1911  Einstein uses special relativity and the
assumption that locally a frame of reference that
is stationary in a gravitational fields is just
like an accelerating frame.  His result is the
light bends.  In this paper he refers to an
earlier paper from 1907.

        The major paper on GR is "The Foundation of the
General Theory of Relativity"  Annalen der Physik,
49, 1916.  But a quick check of reference in
Misner Thorne and Wheeler's massive "Gravitation"
indicates a near continuum of papers struggling
with gravity from 1911 until 1916.  In the
publish  proceeding of a meeting near the end of
1915, Einstein indicates the GR was at that point
logically complete.  The 1916 article put
everything together in one package.

        In Misner Thorne and Wheeler (pages 177-186)
deals with fails in simpler models for gravity.
There is no deflection of light if gravity is a
scalar field.

        As I understand the difference deflection is
about a factor of two.  The difference comes about
because in the GR case, 4-space is NOT Euclidean.

Thanks
Roger Haar
U of AZ

*****************************************
Larry Smith wrote:
> One of the textbooks on my desk says regarding predictions of GR "Gravity
> should bend light rays, an effect not predicted by Newtonian mechanics
> because light has no mass."  Yet
> <http://www.theory.caltech.edu/people/patricia/lclens.html> claims that
> Newtonian gravity bends light, just less than Einsteinian gravity does.
> What gives?
>
> Thanks,
> Larry