Quote:
Originally Posted by DBryan
Why does the Observable Universe appear to be expanding? ... This is simply because the light which we observe from the outer reaches of the universe cannot have travelled further than 14 billion light years since the
beginning.
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As a description of why the OU appears to be expanding, this is not consistent with observation. The expansion of the universe is not derived from observations of the edge of the universe. Rather, it is derived from the observation of the consistent motions of galaxies that are clearly visible, and a lot closer than the edge (
Hubble, 1929). The OU appears to be expanding, quite simply, because we think we can actually see all of its parts expanding away from each other (that is the standard interpretation of cosmological redshifts). That is where the idea of a "big bang" event comes from.
Quote:
Originally Posted by DBryan
Note that we are talking about the OU which is unlikely to bear any resemblance to the CU.
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This is a metaphysical postulate that is in fact directly contradicted by your own description of the expansion of the universe (despite the fact that your description is also incorrect in any case). In your own model, as the OU expands, because we can see farther as time goes on, previously hidden parts of the CU become part of the OU. We can see that the OU is consistent. It does not suddenly change into something bizzare & different. As we see more & more of the CU, it looks just like the old OU. So, if you hold to your own model, you must also hold that the OU & CU are not observationally distinguishable. So the CU must look just like the OU, just bigger.
This in fact is the standard cosmology. Cosmologists are well aware of the fact that the observable universe is only a subset of a bigger universe, and your description of the growth of the OU is correct, but only as a description of its growth, not of its expansion. For instance,
Key, et al., 2007 (Physical Review D 75(8): 084034, April 2007) place a lower bound on the size of the universe of 24 Giga parsec (78.24 billion light years).