[Physicist]

Now supposed instead of the big bang, the light simply passed through shocks waves in cold gases, giving local red and blue shifts.

That wouldn't give you the continuous emission spectrum we see in the CMBR. Where's the light coming from in the first place?

[M Kehoe]

Any commercial applications for this?

5.56mm

[Gary Boldwater]

Consider that the the microwave background radiation is highly scattered. If you look at optical communication systems in highly scattering medium it's impossible to tell where the source is, same for microwave. What is the coherence length of the background radiation as a radial function from earth? We only see the transverse coherence.

Secondly, the background radiation can be the summation of many shifts occuring at different times and places and gives a continuous spectrum. Just look at the spectrum of the spread spectrum radio signal. For just "crude" modulation rates the spectra appears as continuous noise. Imagine if it was encoded over astronomical time periods at very high data rates.

I think it would be telling to look at the nature of low level signals of the cosmic background. Refer to the discussion of the difference between "antenna radiation" and "light" in Dishington's book. If the thesis is correct, one would see the microwave background radiation showing photonic properties (since it is shifted light) rather than the properties of antenna radiation, as this is what most microwave signals are. The properties would show as polarization differences. Light type radiation would show circular polarization at the quantum level (individual photons) and antenna type radiation would maintain the same polarization (linear or circular) regardless of signal level.