This is a map of the multiverse. Or in physics-ese, it’s the maximally extended Penrose diagram of a Kerr spacetime. And in English: when you solve Einstein’s equations of general relativity for a rotating black hole, the universe does not come to an abrupt halt at the bottom of the gravitational pit. Instead, a path can be traced out again but you do not end up in the universe that you started in. As I said, it’s a map of the multiverse.