In A Quilted Multiverse, Literally Anything Is Possible
The quilted multiverse theory postulates the existence of infinite pockets of spacetime on a gravitationally "flat" universe. In this infinite field, anything imaginable could—and indeed, would have to—occur. This means that there would be universes identical to the one we inhabit, as well as universes identical to every fictional world ever created, from Harry Potter's world to Narnia.
from NOVA PBS
Key Facts In This Video
The inflationary multiverse model postulates that "Big Bangs" are forming universes constantly. (0:39)
In a quantum multiverse, the universe is always "splitting" into multiple versions. (2:42)
The brane multiverse theory positions our universe on a plane in one of 10 dimensions. (3:25)