Creation of Universe - Matter/Anti-Matter

During an “is there a God” discussion, someone made a comment about the Big Bang Theory being very possibly wrong. It didn’t have that much to do with our discussion, so we didn’t go into it. I’m curious about it, though.

It is thought that there should be an equal amount of matter and anti-matter in the universe. Matter and anti-matter can’t co-exist, though, yet humans and the rest of the earth are made of matter. How come we don’t just blow up? There seems to be an imbalance of matter and anti-matter.

Is someone familiar with this idea that the big bang could not have happened because of matter/anti-matter.

Our universe is composed of matter in the overwhelming majority, as far as we know. This is itself the leftovers of a tiny imbalance in favour of matter over anti-matter in the the enormous matter-antimatter annihilation near the timeless singularity at one end of our universe.

That theory assumes that the amounts of matter and anit-matter were the exact same at the big bang. That is thought to be false. If I recall, the ratio was something like a billion and one particles of matter to a billion of antimatter. The billions blew each other up, leaving us with the left over one part of matter that we’ve come to know and love.

Why this particular ratio, which is seemingly pretty odd, is an interesting question, but it does not disprove the Big Bang.

IANAC (Cosmologist)