Origin of the universe

Most people agree that there was something they like to call a Big Bang, even though the metric expansion of space is radically different from an explosion. What many people don't agree on is what, if anything, preceded this "Big Bang". Some claim that there was nothing before the Big Bang and are thus apparently willing to believe that time, causation and existence itself did not exist prior to the Big Bang. Others would have you believe a sentient God was bored one day and decided to create the universe because he had nothing better to do. Even others claim two primeval universes banged each other and thusly created the present universe. Personally, I prefer to think there exists an eternal chaosverse which spawns universes at random.