BBC地平线：我们身处哪个宇宙

     Imagine a world where dinosaurs still walk the earth       A world where the Germans won World War II and you are president of the United States       Imagine a world where the laws of physics no longer apply and where infinite copies of you are playing out every storyline of your life       　　It sounds like a plot stolen straight from Hollywood, but far from it       This is the multiverse       　　Until v