🚀 go-pugleaf

Pentcho Valev schrieb:

> On Jan 18, 6:37 am, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
> sci.physics.relativity:
> 
>>Albertito wrote:
>>
>>>Then, why did Einstein propose a local speed of light as
>>>c'= c(1 + V/c2)?
>>
>>Because he was struggling to find General Relativity, but had not yet
>>figured out all the details. His intermediate formula is approximate,
>>but not correct. When he proposed it he did not fully understand the
>>difference between local and non-local phenomena.
>>
>>Tom Roberts
> 
> Roberts Roberts, Einstein's 1911 equation c'=c(1+V/c^2) is consistent
> with the gravitational redshift factor 1+V/c^2 confirmed
> experimentally by Pound and Rebka. 
>

In his 1911 work "�ber den Einfluss der Schwerkraft auf die Ausbreitung 
des Lichtes", Annalen der Physik 35 (1911); translated: "On the 
Influence of Gravitation on the Propagation of Light" Einstein uses the 
equivalence principle to derive the relation for gravitational red-shift

nu_1 = nu_2 (1 + V/c^2)

 From this he concluded that the speed of light must vary according to

c = c_0 (1 + V/c^2)

Using this equation Einstein derives a relation for the deflection angle 
for light passing the sun (1911):

alpha = 2 GM / (c^2 R)

This is wrong by a factor 2. Experimentally is found

alpha = 2 GM / (c^2 R)

> In other words Roberts Roberts, the
> equation c'=c(1+V/c^2) is CORRECT, NOT APPROXIMATE: 
>

This equation is not correct, because it leads to a wrong prediction for 
the deflection of light.  The reason for the error was: In 1911 Einstein 
used "curved time" and "flat space", not curved space-time.

> any different
> equation (that may seem correct to you) would be inconsistent with the
> redshift factor. 
>

The gravitational red-shift is not caused by a variable speed of light.

In his 1916 work "Die Grundlage der allgemeinen Relativit�tstheorie", 
Annalen der Physik 49 (1916) Einstein shows:

* Space-time is described with the metric

   ds^2 = g_mu,nu dx^mu dx^nu

* The gravitiational red-shift depends on the metric:

   nu_B / nu_A = sqrt(g_00(r_A)/g_00(r_B))

* In weak fields the following approximation holds:

   nu_B / nu_A = 1 + Delta V/c^2

* Speed of light:
   - In a local inertial frame of reference the speed of light
     is constant c
   - In general, global coordinates the speed of light varies
     (in weak fields) according to

     c_A = c ( 1 + 2 V/c^2)

* This leads to the correct relation for the deflection angle
   for light passing the sun:

   alpha = 4 GM / (c^2 R)

> For that reason Roberts Roberts superior brothers in
> Einstein criminal cult have always been teaching that the speed of
> light varies with the gravitational potential, in accordance with
> Einstein's 1911 equation c'=c(1+V/c^2):
> 
> http://www.physlink.com/Education/AskExperts/ae13.cfm
> [...]

> http://www.blazelabs.com/f-g-gcont.asp 
> [...]

Probably these "superior brothers" have not read Einsteins 1916 work.

Dieter Heidorn

PS:
For those of you who understand a little german: Einsteins original 
papers that were published in "Annalen der Physik" can be read and 
downloaded here:

http://www.physik.uni-augsburg.de/annalen/history/Einstein-in-AdP.htm