When a medium at rest is moved by a wave pulse does the wave pulse create a locally small variation of density in the medium? If it does then wouldn't some of the energy of the wave pulse be reflected back to the source of the wave pulse?
If this is true then perhaps something analogous can happen to light so that the observed CMB would be the echo of light from our own Sun and the redshift of a remote galaxy would be the result of light energy being reflected back to that galaxy. (According to the theory of special relativity this is a flawed analogy since it says no medium or aether is required for light, but as far as I know no experimental tests of special relativity have looked for reflections from the aether.) Harry
