[TXnMA]

As far as they have been able to discern so far, the antihydrogen spectrum is the same as for normal hydrogen...

If that propagates through all anti-elements, could there be entire anti-galaxies out there?

And, we wouldn't recognize one -- until we stumbled into it -- and were annihilated?

[NativeSon]

You racist ! Anti-matter Lives, matter!

[Theophilus]

Wouldn’t we observe matter/anti-matter galactic collisions/annihilations? Does it matter?