Move a paddle to and fro at a frequency of 10/minute and generate a continuous train of waves in a large pond of still water.
Ask an observer standing in the pond about 5meters away from the source to measure the frequency of the water waves as the waves hit him.
Ask a second observer standing in the pond, say about 20 meters farther from the source, to measure the frequency of the same waves as the waves cross him.
The frequency measured by the first observer would be less than the frequency of oscillation of the paddle. And the frequency measured by the second observer would be even lesser. That is, the farther the observer from the source, the lesser the frequency one measures for the same waves.
And this drop in frequency would occur even when the source and the medium (water) are stationary. In other words, it is n’t because of the Doppler effect.
So unlike what our physics prophets preach, red shift isn’t a proof of a receding source, rather it is a natural phenomenon that occurs as waves propagate in space/medium.
In fact, not only the frequency, but also the velocity and the amplitude of the waves would decrease as waves propagate father and farther from the source. As I have elaborated elsewhere, it is the amplitude (along with frequency) which actually determines a wave’s velocity and not the wave length. https://debunkingrelativity.com/2014/03/22/revamping-wave-mechanics/
Wave mechanics is probably the most messed up topic in the entire discipline of physics and that mess-up has what helped the absurd theories of modern physics to flourish in the religious scientific circles.