Well, if you'll read up on your quantum physics, you'll realize that we really don't know what matter will or won't do. We can only give it probabilities for certain behaviors we've observed in the past.
"Something can't just appear out of nothing- that's another scientific fact! Mike"
As for possible Religious explanations of the big bang, that too would qualify as something we really don't understand. String theory is only now touching on hidden dimensional possibilities that would theorize a bouncing big bang theory wherein the matter in the universe expands as far as the initial energy of the explosion that caused it, and then it starts to shrink, until it all meets again, collapses into a giant black whole, and explodes again.
Oh and to all of you who smoked pot before you read that, I’m really sorry.