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Message: <blockquote data-quote="Umbran" data-source="post: 6687070" data-attributes="member: 177">The issue there is that there's no reason for it to have been "thrust away".  We would have expected the matter and antimatter to have been created in a homogeneous spread - where every matter particle created had its antimatter counterpart right next to it.  It'd be like having an incredibly large and dense bag of mixed vegetables, and finding somehow all the diced carrots spontaneously migrated to one corner of the bag.  Like anything else, you'd notice antimatter by its interactions.  Now, its interactions with other antimatter would look exactly like matter interactions with matter.  So, you can have a star of anti-hydrogen fusing away to anti-helium, and emitting light, and you'd be none the wiser - it'd just look like a star from far away.  You could have a whole galaxy of antimatter stars, and from a distance it would look normal......Except where it met a boundary with normal matter.  Then things go kablooey.  If there were large areas of antimatter within the visible universe, you'd expect to find boundaries between that and the region(s) with normal matter - at those boundaries, matter meets anti-matter, annihilates, and produces X-rays (If I recall the energies correctly - gamma rays if not X-rays).There are, and have been, several X-ray telescopes.  I don't know if any have surveyed for precisely this effect, but a couple of previous telescopes did do full sky surveys.  I think they've looked at enough of the sky that they'd have seen it if it was there.  This suggest that there are no such regions in the visible universe.This is where the hypothesis I mentioned in the other thread comes in.  It posits that, after the big bang, the only regions that fell out of inflation were regions that, for whatever reason (including just statistical variation), just happened to have at least a slight predominance of either matter or antimatter.  So, there's a multiverse of bubbles, separated by the vast inflating deeps, that are dominated by one or the other.  The next universe over may be an antimatter universe.  And this fits nicely into the anthropic principle Freyar mentioned.  We live in the universe we do, because if it wasn't this way, it wouldn't be livable, or even exist.  If we were in a region that had even distribution of matter and anti-matter, it'd never have stopped inflating.</blockquote>

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