The Big Bang did [i]not[/i] create the universe. This is a common misconception that is used to derail the theory by saying "it violates the law of conservation." It doesn't. The fact of the matter (no pun intended) is that we do not know what created the universe. As far as modern physics goes, we can only be determinate if what happens 5.4e^-44 seconds after the "beginning" of time. This is called the Planck epoch. All we can say is, the universe was the size of a Planck length (1.6e^-28 nm) and that all the energy the universe currently holds was packed into this very small area. Rapid expansion happens, so all this energy is super hot, which eventually leads to the building blocks of matter, and so on and so forth until today. We know this occurred because of the expansion of space, basically we backtracked that expansion until we quite literally can't anymore. [i]That[/i] is what the Big Bang says, that time was not always existent. The best answer we have today, is that the Universe was probably never created. Which, given, seems a little odd to think about. I mean, everything has to be created in order to be, correct? Well, it simply only makes sense if the universe was always here. Mind you, I've over simplified a lot of what I'm talking about here to save myself from writing for hours.