# Einstein, Newton and the Pound-Rebka Experiment

#### Pentcho Valev

Einsteinians teach that the gravitational redshift measured in the Pound-Rebka experiment gloriously proved gravitational time dilation, a miracle in Einstein's general relativity:

Professor Jim Al-Khalili, Commander of the Order of the British Empire, Fellow of the Royal Society: "There is another way of slowing time down that does not require high speed travel. Instead, Einstein’s General Theory of Relativity (1915) shows that a gravitational field will do the same job. The effect can even be seen due to the Earth’s gravity but, due to the relatively small mass of our planet, the effect is tiny. Nevertheless, it was measured by two Americans, Pound and Rebka, in 1958 in one of the most precise and beautiful experiments in the whole of physics. Thus clocks run faster out in space than they do on the surface of the Earth. To travel into the future, all you need to do is find a suitable massive object, such as a black hole or neutron star, which has a strong enough gravitational field to significantly warp spacetime in its vicinity, and orbit around it a few times. While doing this your time will flow more slowly than it does in the relatively weaker gravitational field on the surface of the Earth." http://personal.ph.surrey.ac.uk/~phs1ja/1STR/time.pdf

David Morin: "The equivalence principle has a striking consequence concerning the behavior of clocks in a gravitational field. It implies that higher clocks run faster than lower clocks. If you put a watch on top of a tower, and then stand on the ground, you will see the watch on the tower tick faster than an identical watch on your wrist. When you take the watch down and compare it to the one on your wrist, it will show more time elapsed. [...] 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." http://www.personal.kent.edu/~fwilliam/Chapter 13 General Relativity.pdf

"In astrophysics, gravitational redshift or Einstein shift is the process by which electromagnetic radiation originating from a source that is in gravitational field is reduced in frequency, or redshifted, when observed in a region of a weaker gravitational field. This is a DIRECT RESULT OF GRAVITATIONAL TIME DILATION." https://educalingo.com/en/dic-en/einstein-shift

Sometimes Einsteinians test if the more-than-a century brainwashing has completely paralysed the scientific community. Here they inform the community that the gravitational redshift measured in the Pound-Rebka experiment is a direct result of Newton's variable speed of light, not of gravitational time dilation:

Max Planck Institute for Gravitational Physics : "You do not need general relativity to derive the correct prediction for the gravitational redshift. A combination of Newtonian gravity, a particle theory of light, and the weak equivalence principle (gravitating mass equals inertial mass) suffices...The gravitational redshift was first measured on earth in 1960-65 by Pound, Rebka, and Snider." http://www.einstein-online.info/spotlights/redshift_white_dwarfs.html

The scientific community does not react and Einsteinians conclude that, yes, the paralysis is complete. So complete that when Pound and Snider themselves explain that their experiment confirmed Newton's variable speed of light and has nothing to do with gravitational time dilation, the community simply couldn't care less:

R. V. Pound and J. L. Snider, Effect of Gravity on Gamma Radiation: "It is not our purpose here to enter into the many-sided discussion of the relationship between the effect under study and general relativity or energy conservation. It is to be noted that no strictly relativistic concepts are involved and the description of the effect as an "apparent weight" of photons is suggestive. The velocity difference predicted is identical to that which a material object would acquire in free fall for a time equal to the time of flight...The view that the local time scale depends on the gravitational potential appears to require a coherent source for confirmation. The present experiment is unable to distinguish between frequency changes and velocity changes, for example. It appears as if an experimental comparison of clocks at different potentials would make a useful complementary contribution to the over-all status of confirmation of theory." http://virgo.lal.in2p3.fr/NPAC/relativite_fichiers/pound.pdf

#### Pentcho Valev

The top of a tower of height h emits light downwards. If the light falls as per Newton, we have

dL = cdt ; dc = gdt (dL is infinitesimal distance travelled by the light)

Accordingly,

dL/dc = c/g

Integrating gives

c' = c(1 + gh/c^2)

where c' is the speed of the light at the ground (it is assumed that c>>(c'-c)). Accordingly, the frequency at the ground is

f' = c'/λ = f(1 + gh/c^2)

where f=c/λ is the initial frequency (at the top of the tower). That is, the frequency shift is

(f' - f)/f = gh/c^2

Is that the frequency shift measured in the Pound-Rebka experiment? Yes:

"They [Pound and Rebka] 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." http://www.personal.kent.edu/~fwilliam/Chapter 13 General Relativity.pdf

Replies
1
Views
394
Replies
2
Views
483
Replies
12
Views
2K
Replies
1
Views
351
Replies
3
Views
524