- #176
PeterDonis
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Yes.jbergman said:In the MWI there is a branching into "worlds" where a world is isolated from the other worlds that make up the wavefunction.
No, it isn't. Every possible outcome happens. So the probability of any outcome with a nonzero amplitude in the wave function happening is ##1##. It doesn't matter what the weight of that particular outcome is, since that weight makes no difference to whether the outcome happens or not. It always happens as long as there is any nonzero weight at all.jbergman said:Then the probability of something happening or being observed after measurement is literally just,
# of worlds with outcome A / total # of worlds.
In any particular world, you can formulate a notion of "probability" of something happening based on its relative frequency in that world. But that's not the same thing as the ratio you give. This is one of the key issues with formulating a concept of probability in the MWI, and has been discussed in the literature for decades with no resolution.