[MrB (Simon)]

Originally Posted by sjastro

Your line of reasoning contradicts the Cosmological principle.

Never heard of it, so it's somebody else's problem... hehe

If you use red shift to calculate the origin you will find the BB to have occurred in your own backyard.

Red shifted galaxies are moving away from you, or from an observer from any point in the Universe. Doppler red shift is not an absolute parameter but is relative to the position of the observer.

True. You can probably tell I've never read/learnt anything about this and I'm kinda making it up as I go along.
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?

At the scale of the universe, galaxies are essentially evenly distributed. This is a direct consequence of space time expansion which makes the universe homogenic and isotropic.

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.

If you want to use a bubble analogy think of the universe as the surface of the bubble rather than its volume. You will find that every point on the surface is moving away from every other point as the bubble expands.

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?

There is no specific origin.

Regards

Steven

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