In the presence of a gravitational field, the protective belt is called "gravitational time dilation". However the VARIABLE speed of light predicted by Newton's emission theory of light cannot be camouflaged so efficiently as in the field-free situation:
A light source on top of a tower of height h emits light with frequency f and speed c (relative to the source). The light reaches an observer on the ground with frequency f' and speed c' (relative to the observer).
Equivalently, a light source at the front end of an accelerating rocket of length h and accelaration g emits light with frequency f and speed c (relative to the source). The light reaches an observer at the back end with frequency f' and speed c' (relative to the observer).
Consider equations (13.2) on p. 3 in David Morin's text:
http://student.fizika.org/~jsisko/Knjige/Klasicna%20Mehanika/David%20Morin/CH13.PDF
f' = f(1 plus v/c) = f(1 plus gh/c^2) (13.2)
where v is the relative speed of the light source (at the moment of emission) and the observer (at the moment of reception) in the rocket scenario. By combining these equations with:
(frequency) = (speed of light)/(wavelength)
we obtain THE FUNDAMENTAL EQUATIONS OF NEWTON'S EMISSION THEORY OF LIGHT:
c' = c plus v = c(1 plus gh/c^2)
which CONTRADICT EINSTEIN'S 1905 FALSE CONSTANT-SPEED-OF-LIGHT POSTULATE. The fundamental equations of the emission theory can also be obtained from Paul Fendley's text:
http://rockpile.phys.virginia.edu/mod04/mod34.pdf
Paul Fendley: "An experiment to test this idea was done in the early '60s by Pound and Rebka in a tower 20 feet from where my office was as a graduate student. First consider light shined downward in a freely falling elevator of height h. Inside the elevator, we're a happy inertial frame. We say it takes time t=h/c to hit the bottom. We also say that there's no Doppler shift of the frequency of the light. But how does this look from the ground? Say the light beam was emitted just as the elevator was released into free fall (i.e. at zero velocity). By the time the light hits the bottom of the elevator, it is accelerated to some velocity v. Since light travels so fast, the elevator isn't traveling very fast when the light hits the bottom, so v is pretty small, and we can use non-relativistic formulas for this (but not the light!). We thus simply have v=gt=gh/c. Now let's see what this does to the frequency of the light. We know that even without special relativity, observers moving at different velocities measure different frequencies. (This is the reason the pitch of an ambulance changes as it passes you it doesn't change if you're on the ambulance). This is called the Doppler shift, and for small relative velocity v it is easy to show that the frequency shifts from f to f(1 plus v/c) (it goes up heading toward you, down away from you). There are relativistic corrections, but these are negligible here. Now back to our experiment. In the freely-falling elevator, we're inertial and measure the same frequency f at top and bottom. Now to the earth frame. When the light beam is emitted, the elevator is at rest, so earth and elevator agree the frequency is f. But when it hits the bottom, the elevator is moving at velocity v=gh/c with respect to the earth, so earth and elevator must measure different frequencies. In the elevator, we know that the frequency is still f, so on the ground the frequency
f' = f(1 plus v/c) = f(1 plus gh/c^2)
On the earth, we interpret this as meaning that not only does gravity bend light, but changes its frequency as well."
By combining the above equations with the formula:
(frequency) = (speed of light)/(wavelength)
one obtains THE FUNDAMENTAL EQUATIONS OF NEWTON'S EMISSION THEORY OF LIGHT:
c' = c plus v = c(1 plus gh/c^2)
which CONTRADICT EINSTEIN'S 1905 FALSE CONSTANT-SPEED-OF-LIGHT POSTULATE.
The Pound-Rebka experiment, just like the Michelson-Morley experiment in the absence of a protective belt, UNEQUIVOCALLY confirms THE FUNDAMENTAL EQUATIONS OF NEWTON'S EMISSION THEORY OF LIGHT and refutes EINSTEIN'S 1905 FALSE CONSTANT-SPEED-OF-LIGHT POSTULATE:
http://student.fizika.org/~jsisko/Knjige/Klasicna%20Mehanika/David%20Morin/CH13.PDF
David Morin (p. 4): "This GR time-dilation effect was first measured at Harvard by Pound and Rebka in 1960. They sent gamma rays up a 20m tower and measured the redshift (that is, the decrease in frequency) at the top. This was a notable feat indeed, considering that they were able to measure a frequency shift of gh/c^2 (which is only a few parts in 10^15) to within 1% accuracy."
David Morin's text referred to above reappears as Chapter 14 in:
http://www.people.fas.harvard.edu/~djmorin/book.html
Introduction to Classical Mechanics With Problems and Solutions, David Morin, Cambridge University Press
Pentcho Valev pvalev@yahoo.com
