The idea of multiple, parallel universes existing beyond the scope of our own is enormously exciting. Imagine the prospect of infinite other versions of yourself, all with wildly different lives. One of them might be an international sports star; another might be a Nobel Prize winner. It’s fun to think about, but it’s still just an idea. Now, though, scientists think they may have discovered proof of a parallel universe. And the evidence suggests that it might have once crashed into our own.