I would guess that orbital velocities would only affect the observed redshift, and would have little to do with the different paths of light (which is probably what is important here) past the intervening galaxy, though there may be a second-order difference there. I would need to get my head around the relevant bit of cosmology before I could any sort of confidence in all this, though.

@anglophone As you get your head around the relevant bit of cosmology, note that you will see thousands of words about redshift and blackholes but no evidence that

1. redshift is related to Doppler shift and velocity, or
2. blackholes and their enormous gravity exist.
   There is no evidence that light from a moving source and sound from a moving source are both measures of velocity.
   Newton’s gravity mathematics is reliable close to massive bodies such as the sun’s planets and their moons. It is not reliable in outer space where there may be one particle in ten cubic meters.

@yvilletom Newtonian mechanics was debunked by observations of Mercury's orbit around the Sun, which is hardly a massive body in cosmological terms. Redshift and the change in pitch from a source of sound that is moving are mediated by two entirely different mechanisms. Evidence of the existence of black holes comes from the Large Interferometer Gravitional-Wave Observatory.

@anglophone Go to Edwin Hubble and his redshift vs. Doppler hypotheses, not to Georges LeMaitre and his primordial atom fraud.

@yvilletom I have the impression that you have the impression that I do not know what I am talking about. Would that be a fair comment?

@anglophone Here’s a paragraph from the Forum in the current www.thunderbolts.info news:

“The mainstream never had a lick of empirical support to justify any of their claims, but now they have a strong physical laboratory refutation to deal with on top of of their numerous qualification problems. Say so long to mainstream theory, it's about to die a natural empirical death. There has never been a single laboratory observation that was a bigger threat to mainstream theory than that observation of plasma redshift in the lab IMO. Lyndon Ashmore has already written a pretty good paper showing how these laboratory redshift results are not only predicted in Plasma Cosmology/Electric Universe (PC/EU) theory, this successful prediction of PC/EU theory absolutely destroys the credibility of the mainstream's claims related to expansion and acceleration.

Galaxies.