the only legitimate way to define its "size" or "degree of reality" is the L^2 norm
"Degree of reality" - an interesting concept, especially when employed as an explanation of why some things happen more often than others. Why does this coin come up heads twice as often as it comes up tails? Because coming up heads has twice the "degree of reality" of coming up tails. Funny, they both felt equally real when they happened...
Face it: if you are going to assert that the observed frequencies of physical events are explained by the existence of Many Worlds, then the frequencies with which those events occur throughout the Many Worlds have to match the observed frequencies. You are going to have to say that the L^2 norm tells you how many copies of a branch exist, not just that a branch has a "size" or a "degree of reality".
It would be nice if the universe were finite, but you can't demand that a priori; it's enough that the infinite mathematical object obeys simple rules.
I'm saying that if we lived in another universe, and someone came along and described to us the wavefunction for the Schrodinger equation, and asked how we should regard the size of some part of the configuration space compared to some other part, the L^2 norm is the blindingly obvious mathematical answer because of the properties of the wavefunction. And so if we (outside the system) were looking for a &quo...
These are extracts from some Facebook comments I made recently. I don't think they're actually understandable as is—they're definitely not formal and there isn't an actual underlying formalism I'm referring to, just commonly held intuitions. Or at least intuitions commonly held by me. Ahem. But anyway I figure it's worth a shot.
A proposal to
rationalizederive magick and miracles from updateless-like decision theoretic assumptions:(On Google+ I list my occupation as "Theoretical Thaumaturgist". ;P )