Antimatter Universe: Same or Different?

[abuguchie]

What would the universe be like in contrast to what it is now if it were made out of antimatter? Or would it be exactly the same?
Thanks.

 

[mathman]

There might be slight differences, since there is some difference in the decay properties of particles compared to anti-particles.

 

[ibysaiyan]

My guess is that it would be reverse to ours ? Just as Richard feynman had described about anti-matter.
By the way I just read an article stating the creation of the anti-particle counterpart of Helium-4

 

[Drakkith]

What would be reverse about it? As fas as I know there would be almost no discernible differences between ours and their universes.

 

[Bill_K]

The first thought is, it would be the same. However there is some reason, still unknown to us, why our universe is predominantly matter. Was it really just random chance? Without an understanding of that issue, it's impossible to answer your question. There are apparently differences between matter and antimatter which we have not yet discovered. An antimatter universe sounds possible, but may not be.

 

[abuguchie]

Could there be an antimatter universe parallel to ours? If so what would the "boundary" between the two be like?