Surely if there is more distance between any two galaxy groups today than there was yesterday they are moving apart, whatever the mechanism.
That is what I was trying to differentiate between; moving and separating. It is one of those weird physics things. I don't think there are really any good analogies. Going back to the red shift thing with distant galaxies. Typically a shift in wave length is associated with the Doppler effect. But the red shift for distant galaxies isn't really a Doppler effect. It is because the space between has been stretched and the light waves which are 'anchored' to space have been stretched with it. As I understand it if you can do the math you can figure it all out using GR. I can't and am not ready to go back to school to work on an advanced degree just so I can. So I think as far as I am concerned I will just accept the word of the people who do understand the math that it works that way.
Sorry I can't be more help.
Bill Gill
