Recently, we discussed a new paper that suggests our universe was not the only one that popped into existence after the big bang, but that a 'mirror universe' did as well. This universe can be thought of as the bizzaro to our Kal-el: it's a place where everything—the microworld and all, even the arrow of time—is opposite of ours.
Of course, the idea wasn't devised for the cool factor. Rather, they believe this "event" would bring clarity to several key issues that remain with the big bang model, including certain contradictions of established laws of physics (like the original state of entropy, and the second law of thermodynamics, to name a few).
In this video, Fraser Cain from UniverseToday examines this hypothesis, and how such a mirror universe may work
WATCH:"Is There a Mirror Universe?"
You can read a more thorough analysis here.