4 ms·

Multiverse Collisions May Dot the Sky

43 points by digital55 12y ago

zw123456 12y ago
What if out universe was a matter universe and 14B yrs ago it collided with an anti-matter universe and that was the big bang? An our universe was just a little bigger than the other one? It seems like would explain a lot, like why the universe is so empty.
aroberge 12y ago
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?
trhway 12y ago
>The team concluded that a collision of two bubble universes would appear to us as a disk on the CMB with a distinctive temperature profile. we don't expect them to be real bubbles with real walls, don't we? Thus, once the collision happened, the Universes get entangled, and, continuing the expansions, the matter/space from each other should continue penetrating deeper and deeper into each other (like 2 garbage trucks colliding in slow motion). So it should be not just CMB temperature disk - looking at that direction we'd be actually looking at matter/space from the other Universe.
- ccvannorman 12y ago
  >like 2 garbage trucks colliding in slow motion The best description of a QM interacting multiverse ever

43 points by digital55 12y ago

What if out universe was a matter universe and 14B yrs ago it collided with an anti-matter universe and that was the big bang? An our universe was just a little bigger than the other one? It seems like would explain a lot, like why the universe is so empty.

aroberge 12y ago

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?

trhway 12y ago

>The team concluded that a collision of two bubble universes would appear to us as a disk on the CMB with a distinctive temperature profile. we don't expect them to be real bubbles with real walls, don't we? Thus, once the collision happened, the Universes get entangled, and, continuing the expansions, the matter/space from each other should continue penetrating deeper and deeper into each other (like 2 garbage trucks colliding in slow motion). So it should be not just CMB temperature disk - looking at that direction we'd be actually looking at matter/space from the other Universe.

ccvannorman 12y ago
>like 2 garbage trucks colliding in slow motion The best description of a QM interacting multiverse ever