Yep. Until/unless our understanding of physics improves, we can’t get any evidence for or against MWI. Our only reason for preferring it is that it sounds simple and thus should have lower prior. But it’s a weird kind of “narrative simplicity”, not mathematical (Kolmogorov) simplicity, because mathematically there’s only one quantum mechanics and no interpretations. So I wonder why people care about MWI as anything more than an (admittedly very nice) intuition pump for studying QM.
So I wonder why people care about MWI as anything more than an (admittedly very nice) intuition pump for studying QM.
MWI says (in part) that we don’t have to make wave function collapse an integral part of the mathematical formulation of quantum mechanics. Since, historically, wave function collapse has been a part of the mathematical formulation of quantum mechanics, that seems sufficient reason to care about MWI.
I think you’re equivocating on “mathematical formulation”. We want theories to predict the future. The algorithm that assigns probabilities to your future observations is the same, and equally mysterious, across all interpretations. MWI does raise the tantalizing possibility that the Born rule might not be part of basic physics—that it might somehow emerge from a universe without it—but AFAIK this isn’t settled yet.
Good point, I missed that. So MWI seems to be even subjectively unconfirmable...
Yep. Until/unless our understanding of physics improves, we can’t get any evidence for or against MWI. Our only reason for preferring it is that it sounds simple and thus should have lower prior. But it’s a weird kind of “narrative simplicity”, not mathematical (Kolmogorov) simplicity, because mathematically there’s only one quantum mechanics and no interpretations. So I wonder why people care about MWI as anything more than an (admittedly very nice) intuition pump for studying QM.
MWI says (in part) that we don’t have to make wave function collapse an integral part of the mathematical formulation of quantum mechanics. Since, historically, wave function collapse has been a part of the mathematical formulation of quantum mechanics, that seems sufficient reason to care about MWI.
I think you’re equivocating on “mathematical formulation”. We want theories to predict the future. The algorithm that assigns probabilities to your future observations is the same, and equally mysterious, across all interpretations. MWI does raise the tantalizing possibility that the Born rule might not be part of basic physics—that it might somehow emerge from a universe without it—but AFAIK this isn’t settled yet.
It should be called the MWH (Hypothesis) - not the MWI (Interpretation).
See: Q16 Is many-worlds (just) an interpretation?