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This suggestion glosses over a major point. In inflationary models, it is often concluded that our visible universe is a tiny fraction of the rest of the "univ

This suggestion glosses over a major point. In inflationary models, it is often concluded that our visible universe is a tiny fraction of the rest of the "universe", where by "universe" one means something like a bubble described in this article. I know of no model that would yield something where our visible universe's CMB "boundary" would be close to the boundary of the bubble. If there is a collision between these bubbles, the imprint that would be left on the CMB would almost certainly be outside our visible universe.

Florin_Andrei 12y ago
Doesn't it depend on when the collision happened?
- aroberge 12y ago
  No, not really. During inflation, points separated by a finite distance quickly see the distance between increase at a rate faster than the speed of light in vacuum. (This is not a violation of special relativity that says that information can not be transmitted faster than the speed of light.) So, if a collision happened at any point outside of the visible universe, its influence would have quickly been swept away from the edge of our visible universe. The only way that there might have been some evidence left would be if the collision had happened essentially exactly at what is currently the edge of our visible universe. Statistically, this is extremely unlikely to say the least.
wuliwong 12y ago
That's interesting, I hadn't realized that. I thought this was actually pretty interesting, at least it was an attempt to look a data instead of just theoretically speculation. This reminds me of Neil Cornish's past work. http://scholar.google.com/citations?view_op=view_citation&hl=en&user=_No9jXMAAAAJ&citation_for_view=_No9jXMAAAAJ:d1gkVwhDpl0C http://scholar.google.com/citations?view_op=view_citation&hl... He and his colleagues were trying to find evidence of the large-scale structure of the universe. I wonder if this woman or her colleagues found inspiration in that work?

Florin_Andrei 12y ago

Doesn't it depend on when the collision happened?

aroberge 12y ago
No, not really. During inflation, points separated by a finite distance quickly see the distance between increase at a rate faster than the speed of light in vacuum. (This is not a violation of special relativity that says that information can not be transmitted faster than the speed of light.) So, if a collision happened at any point outside of the visible universe, its influence would have quickly been swept away from the edge of our visible universe. The only way that there might have been some evidence left would be if the collision had happened essentially exactly at what is currently the edge of our visible universe. Statistically, this is extremely unlikely to say the least.

wuliwong 12y ago

That's interesting, I hadn't realized that. I thought this was actually pretty interesting, at least it was an attempt to look a data instead of just theoretically speculation. This reminds me of Neil Cornish's past work. http://scholar.google.com/citations?view_op=view_citation&hl=en&user=_No9jXMAAAAJ&citation_for_view=_No9jXMAAAAJ:d1gkVwhDpl0C http://scholar.google.com/citations?view_op=view_citation&hl... He and his colleagues were trying to find evidence of the large-scale structure of the universe. I wonder if this woman or her colleagues found inspiration in that work?