That experiment, carried out by Pound and Rebka, intended to cancel a Doppler redshift with a blueshift predicted by a certain theory of gravity.
Many tests of this theory have been designed to demonstrate constraints on a set of ten parameters named for Nordtvelt and Will. One test of this theory was a measurement of the Shapiro delay by the Cassini-Huygens probe, which also set a new lower bound at around forty thousand for omega, the coupling constant in Brans-Dicke theory. One test of this theory used a Mylar bag full of helium to minimize scattering while a vibrating loudspeaker cone on top of Jefferson Laboratory contained an iron sample emitting gamma rays. That experiment, carried out by Pound and Rebka, intended to cancel a Doppler redshift with a blueshift predicted by a certain theory of gravity. For 10 points, name this theory advanced by Einstein.
Many tests of this theory have been designed to demonstrate constraints on a set of ten parameters named for Nordtvelt and Will.
tests of general {relativity} [accept {clear knowledge} equivalents]