Quote:
Originally Posted by Robh
From my reading of the proposed model it is in fact static space i.e. not expanding. But galaxies are receding from each other with unchanging velocities.
The paper talks of a common point of divergence. However, an observer at any point, not necessarily the point of origin, will still see other galaxies moving away from each other. The cosmological principle, as anything else in Science, is not immutable. However, I see no reason why the cosmological principle can't be applied to the current state of the universe. As all galaxies have moved away from the point of origin, it is no longer part of our observed universe. If galaxies extend beyond the event horizon in every direction, then our universe is what we see - seemingly the same in every direction.
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The only time there can be a common point of origin and all the galaxies experience moving away from each other is if that point of origin lies outside the universe, completely. This is including the observable universe and the universe as a whole. Otherwise, you have a preferred frame of reference and this immediately violates the cosmological principle. All the observation that have been made point to the universe being isotropic and homogeneous on the largest of scales. For that to be the case, there cannot be a preferred frame of reference to the matter-energy density within the universe, otherwise it would've been detected.
The first premise of a static universe in which all the galaxies are moving away from one another makes no sense. You have a finite sized container with all its contents racing away to...where??. Eventually the galaxies will crowd to a point, or several points near the edge of the universe because at some stage, they will have to change their direction of motion tangential to their original motion vector....there's no more space to move in even if the universe is finite but unbound. This would already be occurring for the farthest galaxies, yet we see no evidence for this type of motion in the observations. Occam's Razor, ergo, it's not occurring. It would also mean that the redshift being detected is solely a Doppler shift and not a Hubble redshift....then you would have to explain those galaxies which exhibit a blueshift to their spectrum.
Then you have the problem that not all galaxies are, in fact, moving away from one another in the way that's been observed. If you have a preferred frame of reference because of a defined point of origin within the universe, you cannot have all the galaxies moving away from one another in all directions because some will have to be moving at a tangent to your motion. There's no way around it. Yes, you may be able to say that all the galaxies are in fact moving away from one another, with careful observation, but you would also be detecting galaxies whose motion would have a partial vector of movement across your line of sight. It would be akin to proper motion. This hasn't been observed.