[sjastro]

Originally Posted by MrB

The furthest galaxies are moving at the same speed aren't they?
Does the level of redshift vary between these galaxies or is it the same for all?
I suppose if the observer(us) is too close to the 'origin', or the galaxies are at such distance that we appear to be close to the 'origin', then the delta-redshift (redshift's-shift(!)) between each galaxy would be minimal.
But assuming the observer is sufficiently removed from the origin, then the amount of redshift each galaxy has, their apparent speed, would be an indication of angle of movement relative to the observer?

There is a linear relationship between redshift and velocity (and distance) between the observer and galaxy provided the galaxy is not gravitationally influenced. If the furthest galaxies are at the same distance from the observer they will have the same velocity and redshift.

If galaxies are not gravitationally influenced they will not have an apparent speed nor travel at an angle different to the line of sight of the observer.
The point is that galaxies don't travel through space, they are in a fixed position and are swept along by the expansion of space time. Since space time expands in all directions galaxies are always in the line of sight of the observer.

If galaxies are gravitationally influenced such as being part of a cluster things are more complicated. The red shift/distance/velocity relationship is not as straightforward. The motion may no longer be in the line of sight of the observer and may even be approaching the observer. That's were your vector diagrams will come into play.

Originally Posted by MrB

Not from the 3d plots/maps I've seen, there are clusters and strings and swirls etc etc. The position of the galaxies relative to each other is of no consequence anyway, only their true velocity/apparent velocity and the vector calculated(if possible?) from them.

The 3D slices only represent a small percentage of the Universe. Due to the isotropic nature of the Universe an astronomer ten billion light years away will find the same sort of configurations in their own maps.

Originally Posted by MrB

Yep true, but again, observed from any point within the bubble, (or outside for that matter) other than the 'origin', the velocity of the surface at any point other than those perpendicular to the observer, will have different apparent velocities due to the angle of observation.
I failed physics at high school, it bored me shickless, but do remember vector diagrams... these should apply here right?

The surface of the bubble was meant to be an analogy for the expansion of the Universe nothing more. I'm sorry I raised the issue.

Originally Posted by MrB

Of course there was, we just havent found it yet.
Hope my dribble above makes sense?

You queries are perfectly sensible.

Regards

Steven