🚀 go-pugleaf

On Thu, 26 Mar 2009 00:38:18 -0700 (PDT), Pentcho Valev <pvalev@yahoo.com>
wrote:

>On Mar 26, 9:09�am, hw@..(Dr. Henri Wilson) wrote:
>> Welcome back Hanson, I was getting worried about you...thought the libel police
>> might have gottten you.
>> The Einstein dingleberries can't make up their minds whether or not the factor
>> of two actually exists. If it does, they are stuffed. If it doesn't they are
>> still stuffed....
>
>Just in case, Einsteiniana's Masters teach that "the factor of two"
>both exists and does not exist:
>
>http://www.physlink.com/Education/AskExperts/ae13.cfm
>"So, it is absolutely true that the speed of light is not constant in
>a gravitational field [which, by the equivalence principle, applies as
>well to accelerating (non-inertial) frames of reference]. If this were
>not so, there would be no bending of light by the gravitational field
>of stars....Indeed, this is exactly how Einstein did the calculation
>in: 'On the Influence of Gravitation on the Propagation of Light,'
>Annalen der Physik, 35, 1911. which predated the full formal
>development of general relativity by about four years. This paper is
>widely available in English. You can find a copy beginning on page 99
>of the Dover book 'The Principle of Relativity.' You will find in
>section 3 of that paper, Einstein's derivation of the (variable) speed
>of light in a gravitational potential, eqn (3). The result is,
>c' = c0 ( 1 + V / c^2 )
>where V is the gravitational potential relative to the point where the
>speed of light c0 is measured."
>
>http://www.mathpages.com/rr/s6-01/6-01.htm
>"In geometrical units we define c_0 = 1, so Einstein's 1911 formula
>can be written simply as c=1+phi. However, this formula for the speed
>of light (not to mention this whole approach to gravity) turned out to
>be incorrect, as Einstein realized during the years leading up to 1915
>and the completion of the general theory. In fact, the general theory
>of relativity doesn't give any equation for the speed of light at a
>particular location, because the effect of gravity cannot be
>represented by a simple scalar field of c values. Instead, the "speed
>of light" at a each point depends on the direction of the light ray
>through that point, as well as on the choice of coordinate systems, so
>we can't generally talk about the value of c at a given point in a non-
>vanishing gravitational field. However, if we consider just radial
>light rays near a spherically symmetrical (and non- rotating) mass,
>and if we agree to use a specific set of coordinates, namely those in
>which the metric coefficients are independent of t, then we can read a
>formula analogous to Einstein's 1911 formula directly from the
>Schwarzschild metric. (...) In the Newtonian limit the classical
>gravitational potential at a distance r from mass m is phi=-m/r, so if
>we let c_r = dr/dt denote the radial speed of light in Schwarzschild
>coordinates, we have c_r =1+2phi, which corresponds to Einstein's 1911
>equation, except that we have a factor of 2 instead of 1 on the
>potential term."

You're right again Pencho.

>
>Pentcho Valev
>pvalev@yahoo.com



Harry Wilson. ASTC,BSc,DSc(T)

www.users.bigpond.com/hewn/index.htm.

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