Uh huh. See:
"What unique predictions does many-worlds make?"
"Could we detect other Everett-worlds?"
"Many worlds is often referred to as a theory, rather than just an interpretation, by those who propose that many worlds can make testable predictions (such as David Deutsch) or is falsifiable (such as Everett)"
OK, thanks. I see that many-worlds could be falsifiable, if the many-worlds interact (or interfere). I really didn't know that was on the table.
Eliezer Yudkowsky and Scott Aaronson - Percontations: Artificial Intelligence and Quantum Mechanics
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