There is a priciple in science called Ockham's razor: If you have two different hypotheses that both explain the same observation, the hypothesis that is less complicated and makes less assumptions is normally the true one.

If we apply Ockham's razor to the creation of the universe, all the scientific theories about the cause of the Big Bang - phase shift theories or multiverse theories - become a lot more likely than the theory of an unexplainable creator.