The Big Bang and Ex Nihilo (out of nothing)

We have this very solid conclusion that the universe had an origin, the Big Bang. Fifteen billion years ago, the universe began with an unimaginably bright flash of energy from an infinitesimally small point. That implies that before that, there was nothing. I can’t imagine how nature, in this case the universe, could have created itself. And the very fact that the universe had a beginning implies…