Dear PF Forum, In less than 1 second after big bang, baryons were created. And there's asymmetry in it. Can anyone help me? 1. Is it physically possible for a galaxy made entirely from anti matter? 2. If it's true, is it statistically possible for a galaxy made entirely from anti matter? If it's true, then I'd like to know the answer question here. No information can come out black hole. Only their mass, and with it their gravity. 3. Is it possible for us to tell that this black hole originator is matter or anti matter? Or you guys scientist just say, well No information can come out black hole. So we don't know 4. Does "matter" black hole differ from "anti matter" black hole? If question number 3 is true. 5. If question number 4, what if we throw an anti matter black hole to a matter black hole? A. Will they explode? B. Will they gets bigger. By "bigger" I mean their schwarzshild radius, of course its size is always zero if it's a singularity. Because, by logic. The explosion will generate more energy E = (m(Matter Black Hole) + m(Anti matter black hole)) x c2 And this E will eventualy become m, right? m = E/c2 But where is this m come from? Matter? Anti matter? I just want to know if my logic in question 5 is right. Consider this: A star, 1 solar mass comes from the north of our sun and hit our sun. What happen? Okay...., there's blast. Earth are surely destryoed. Solar system is destroyed, some TNO might survive. Okay... So what I'd like to know is, What if a matter+anti matter black hole collide? Will it explode like the sun, or will it getting bigger? But first of all we must be sure that Anti matter galaxy is physically possible, statistically possible, matter and anti matter black hole is different and ... they collide. Thanks for any answer.