Quick Philosophical Enlightenment.

To an antimatter universe where everything is the same and all the same events occur(ed), wouldn't we be an antimatter universe.

In other words, we could be an antimatter universe considering normal matter universes as antimatter. hmmph

Either there are some unknown restraints that prevents an antimatter Universe to exist within the domain of our physical laws or a yet unknown huge part of our Universe may already contain large quantities of antimatter with the possibility of aliens that would consider us to be of the "anti"-cind.

 

The baryon asymmetry problem in physics refers to the apparent fact that there is an imbalance in baryonic matter and antibaryonic matter in the universe. Neither the standard model of particle physics, nor the theory of general relativity provide an obvious explanation for why this should be so; and it is a natural assumption that the universe be neutral with all conserved charges. The Big Bang should have produced equal amounts of matter and antimatter; as such, there should have been total cancellation of both. In other words, protons should have cancelled with antiprotons, electrons with antielectrons (positrons), neutrons with antineutrons, and so on for all elementary particles. This would have resulted in a sea of photons in the universe with no matter. Since this is apparently not the case, after the Big Bang, some physical laws must have acted differently for matter and antimatter.

 

There are competing theories to explain the matter-antimatter imbalance that resulted in baryogenesis, but there is as yet no one consensus theory to explain the phenomenon.

 

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Another possibility is that antimatter dominated regions exist within the universe, but outside our observable universe. Inflationary cosmology models suggest that the there may be more to the universe than can be seen from the Earth, if only for the simple reason that the universe isn't old enough for light from the most distant parts of the universe to have reached us yet. If so, radiation from the boundary of matter and antimatter dominated regions may simply still "be on its way" to Earth, and so cannot be observed.

http://en.wikipedia.org/wiki/Baryon_asymmetry

The real question is, does it matter or antimatter? haha

We've not found a "proper" difference between antimatter and matter that would allow us to say which should be the one called "anti", other than that our universe is made of the one we decided to call matter. There's expected to be some sort of difference that would account for matter being dominant (parity violation), but if something somehow had simply separated matter and antimatter than maybe there is no parity violation