🚀 go-pugleaf

On Oct 29, 12:09 am, Pentcho Valev <pva...@yahoo.com> wrote:
On Oct 29, 12:09 am, Pentcho Valev <pva...@yahoo.com> wrote:
> ...you will have to give a straightforward answer to
> the following question: Are the "strongest validations of GR"
> consistent with Einstein's 1911 equation c'=c(1+V/c^2) or are they
> consistent with Einstein's final equation c'=c(1+2V/c^2)?


This was already answered last week. Here's the answer again.

On Oct 24, 12:20 am, Pentcho Valev <pva...@yahoo.com> wrote:
> The speed of light varies with the gravitational potential V and
> Einstein has given two respective equations: c'=c(1+V/c^2), Einstein's
> 1911 equation, and c'=c(1+2V/c^2), his final decision.

The link you cited clearly explains that, in the completed theory of
general relativity, when expressed in terms of Schwarzschild
coordinates near a spherically symmetrical mass, the speed of light is
1 + 2V in the radial direction and 1 + V in the tangential direction.

In 1911 Einstein was working on a theory with a scalar potential that
gave a speed of light that depended only on position, given by 1 + V,
but by 1915 he had realized this doesn't work. It's necessary for the
speed of light to depend not just on the location, but also on the
direction. This means instead of a "scalar potential" he needed a
"tensor potential". It so happens that the scalar formula he gave in
1911 was correct for the tangential direction, but not for the radial
direction.

> Both hypnotists and zombies in Einstein criminal cult should stop
> repeating "Not variable locally" (a rather silly red herring)...

That isn't exactly a "red herring", it's just stated rather sloppily.
The point is that, in general relativity, the coordinate system can be
chosen arbitrarily (the field equations are generally covariant), so
the "speed of light" depends on the choice of coordinate system. This
is also true in special relativity, but in that case there is a
natural "best" choice of coordinate systems, namely, the inertial
coordinate systems, and in terms of those coordinates the speed of
light is always c.  In general relativity there is no longer a
natural
best choice of coordinate systems, because it isn't possible to define
a global inertial coordinate system (due to the curvature of
spacetime). It's like trying to define a Cartesian coordinate system
over the whole surface of the Earth. So we have to use some other
coordinate systems, like Schwarzschild coordinates, in terms of which
the speed of light is 1+2V radially and 1+V tangentially. Note that
the Schwwarzschild coordinates are NOT an inertial coordinate system.
The point of the "red herring" as you call it, is that we can always
define a LOCAL inertial coordinate system, in terms of which the speed
of light is c, just as in special relativity. This is essentially just
another way of expressing the Equivalence Principle. So it isn't a red
herring at all.

On Oct 29, 12:09 am, Pentcho Valev <pva...@yahoo.com> wrote:
> ...you will have to give a straightforward answer to
> the following question: Are the "strongest validations of GR"
> consistent with Einstein's 1911 equation c'=c(1+V/c^2) or are they
> consistent with Einstein's final equation c'=c(1+2V/c^2)?

The best measurements today are based on the tensor potential that
gives a speed of light (in terms of Schwarzschild coordinates) that
varies both as a function of position and as a function of direction.
The two formulas you gave are just two special cases, corresponding to
the speed of light in the tangential and radial directions. In
general, the direction of a light pulse may be neither purely radial
nor purely tangential, so the actual speed is more complicated than
either of those formulas.