"This is actually based on an outdated argument. We don't have a law of conservation on the quantum level. That's more of a Newtonian thing. In the quantum world, even vacuum has energy and there have been experiments to prove this."
"Precisely. The Universe is not a sterile environment. It's a huge mess of just about every atomic combination that can form... which then eventually mix with other formations, and so on, and so forth.
... and the Universe had billions of years…"
"Well the fact that time began at the Big Bang and didn't exist beforehand is a good point. But we've got to remember that the actual Big Bang occurred in an interval less than the Planck Time, so there really isn't a conceivable way…"