An interesting post on the suggestion by Susskind & Bousso that "the multiverse and the many worlds interpretation of quantum mechanics are formally equivalent." But this only holds if we are in a "supersymmetric multiverse with vanishing cosmological constant":
If the universe takes this form, then it is possible to carry out an infinite number of experiments within the causal horizon of each other.Clear? Well, no of course not, and its untestable. But still, of interest.
Now here's the key point: this is exactly what happens in the many worlds interpretation. At each instant in time, an infinite (or very large) number of experiments take place within the causal horizon of each other. As observers, we are capable of seeing the outcome of any of these experiments but we actually follow only one.
Bousso and Susskind argue that since the many worlds interpretation is possible only in their supersymmetric multiverse, they must be equivalent. "We argue that the global multiverse is a representation of the many-worlds in a single geometry," they say.
They call this new idea the multiverse interpretation of quantum mechanics.
UPDATE: Mathematician Peter Woit at Not Even Wrong says that even he can't really make sense of this and other papers that try to draw similar multiverse/quantum theory connections, so don't feel so bad!