Is this the only universe?

Our universe could be just one small piece of a bubbling multiverse. Human history has been a journey toward insignificance. As we’ve gained more knowledge, we’ve had our planet downgraded from the center of the universe to a chunk of rock orbiting an average star in a galaxy that is one among billions. So it only makes sense that many physicists now believe that even our universe might be just a small piece of a greater whole. In fact, there may be infinitely many universes, bubbling into e...