The discussion revolves around the equivalence principle in the context of inertial and non-inertial frames, exploring its implications from both Newtonian and relativistic perspectives. Participants examine the indistinguishability of physical laws in freely falling frames within a gravitational field and uniformly accelerating frames in Minkowski spacetime.
Participants express both agreement and disagreement on various interpretations of the equivalence principle. While some aspects are accepted, there remains uncertainty and differing views on the implications and derivations related to Newtonian physics and the nature of gravitational forces.
Some participants note that the discussion involves complex interpretations of the equivalence principle and its relationship to different frames of reference, which may lead to misunderstandings regarding the distinctions between inertial and non-inertial frames.
DAH said:The Pound-Rebka experiment successfully detected a blueshift in light when photons were sent towards the surface of the Earth from a height of 22.6 m. The formula for the blueshift is given by: $$
z=-\frac{gh}{c^{2}}$$
However, I was thinking about how the blueshift would be observed over time in the accelerating frame, and i came across this paper: https://arxiv.org/abs/1907.06332
According to the paper above the blueshift would drift with time and if photons were sent in the other direction then the redshift will also drift with time. The formula for the blueshift drift is given by:
$$z=-\frac{aL}{\left ( c+at \right )^{2}}$$
So, I would like to know, if this is a flaw in EP and could this experiment be used to distinguish between gravity and an accelerating frame?
... on page 19 of that paper:TABLE I: Redshift ##z_−## and blueshift ##z_+## between co-moving objects in uniformly accelerated reference frames calculated with different approaches.
PeterDonis said:I see what you're saying, but I need to reconcile it with other things I know about the Bell congruence.