Consequences of gradients of rg (and related experimental evidence)
     As discussed on page 28, a gradient of rg exists around Earth. At sea level, rg is less than rg above sea level, and the frequency of the photons emitted by an atom at sea level is lower than the frequency of the photons emitted when the atom is above sea level. This is consistent with an experiment conducted by R. Pound and G. Rebka, Jr. at Harvard in 1960 in which photons (gamma rays) were emitted at the bottom and at the top of a 22.57 m high apparatus. Photons emitted at the top were absorbed at the bottom and vice versa. The experiment showed that photons which had been emitted at the top had a higher frequency upon reaching the bottom than the photons which were emitted at the bottom. And photons which were emitted at the bottom had a lower frequency upon reaching the top than the photons emitted at the top.

     These results are an important part of the experimental evidence supporting general relativity theory, which attributes the difference in photon frequencies between the top and bottom to a "gravitational redshift" of the photons traveling from bottom to top and a "gravitational blueshift" of photons traveling from top to bottom.

     In the qm view, the frequencies of the photons do not change as they travel between the top and bottom of the apparatus. The photons emitted at the top have a higher frequency than the photons emitted at the bottom. The difference in emission frequencies of the photons is due to the difference in rg between the top and bottom. According to the rg equation, a 22.57 m change in elevation at Earth's surface results in a change in rg of 2.45E−15. This agrees with the Pound-Rebka experiment where the measured differences between frequencies at the top and bottom of the apparatus were 2.5 parts in 1E15.

     Clocks and other processes are slowed in proportion to rg, just as they are slowed in proportion to rv, but rg and rv have different effects on the sizes and masses of bodies. Whereas bodies are foreshortened in proportion to rv only in their direction of absolute motion, bodies are reduced in size in all directions in proportion to rg. Therefore, a body is reduced to one eighth of its rg=1 volume when moved to an environment where rg=.5. And whereas a body's mass is inversely proportional to rv, it is directly proportional to rg.