Sorry about my lack of knowledge here and thanks to the membership for at least being tolerant of it.
This one has always bothered me. If a galaxy is constantly gaining mass then could it also constantly affect the Doppler effect? Would not a larger mass have more of an effect on light waves then one of lesser mass? I'm thinking that an ever increasing mass would constantly stretch light waves. If this is so then is the expansion of the universe, the stretching of space, merely a result of mass increases of the heavenly bodies? Is there an actual increase in the distance between these objects?
Part II: As an object accelerates it gains mass. Would the same Doppler Effect be noticed between stars for instance, if you were travelling in a spaceship towards one? In other words would it appear as if space is being stretched even if you are accelerating towards an object in space?