Originally Posted By: Bill S.
As I see it, the reason we would be measuring our speed relative to our neighbours as the same in both places is that the location we left and the destination location would both be travelling at approximately the same speed relative to their neighbours. In the case of an expanding universe, this would apply whether the mechanism involved galaxy groups being transported by expanding space, or travelling through space.

The thing about this is that just moving from here to there wouldn't change our proper motion. We would still have the same proper motion with respect to our neighborhood. And our proper motion with respect to the new neighborhood would be roughly the same. That is both places have roughly the same proper motion.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.