Or more interestingly it may occur in very ordinary circumstances—the vacuum does not have to be even metastable. Think of an (idealized) pin standing on it’s tip, on a glass plane. Suppose that whole thing is put on a moving train—for any train trajectory, there is an initial position for the pin so that it will not fall. That pin would seem to behave quite mysteriously—leaning back just before the train starts braking, etc—even though the equations of motion are very simple. Seems like a good way to specify apparently complicated behaviours compactly and elegantly.
(edit2: Rather than seeing it as worlds being destroyed, I’d see this as an mathematically elegant single world universe, or a mathematically elegant way to link quantum amplitudes to probabilities (which are the probabilities that the one surviving world will have such and such observations) )
Or more interestingly it may occur in very ordinary circumstances—the vacuum does not have to be even metastable. Think of an (idealized) pin standing on it’s tip, on a glass plane. Suppose that whole thing is put on a moving train—for any train trajectory, there is an initial position for the pin so that it will not fall. That pin would seem to behave quite mysteriously—leaning back just before the train starts braking, etc—even though the equations of motion are very simple. Seems like a good way to specify apparently complicated behaviours compactly and elegantly.
(edit2: Rather than seeing it as worlds being destroyed, I’d see this as an mathematically elegant single world universe, or a mathematically elegant way to link quantum amplitudes to probabilities (which are the probabilities that the one surviving world will have such and such observations) )