How Many Universes Are There?

The universe is big, but it’s peanuts compared to the eternally inflating multiverse. But just how many universes are there? What are they like? And most importantly, what can they tell us about … aliens? Imagine it: the observable part of our universe is 93 billion light years across, and that’s just a small fraction of the stuff created in our Big Bang. But in the eternal inflation picture, ours is just one among uncountable bubble universes. Bubbles that are continuously appearing and growing within a vastly larger spacetime that itself expands at an exponentially accelerating rate. A greater inflationary spacetime whose expansion never ends. We looked at the bizarre idea of eternal inflation in recent episodes – but we stopped short of exploring the full implications of this proposition. Those implications are, frankly, completely nuts. Some may also be true.