On Sat, Nov 16, 2024 at 03:52:25PM +1100, Bruce Kellett wrote: > > On Sat, Nov 16, 2024 at 3:28 PM Russell Standish <[email protected]> > wrote: > > On Sat, Nov 16, 2024 at 03:08:03PM +1100, Bruce Kellett wrote: > > On Sat, Nov 16, 2024 at 2:41 PM Russell Standish <[email protected]> > wrote: > > > > I don't think it requires this assumption. In fact "physically real" > > is a rather nebulous concept anyway. > > > > > > If you want the 'other worlds' to be physically real, then the original > wave > > function must be physically real. > > That's a non-sequitur. The 'other worlds' are as real as this one. The > reality of the wave function doesn't enter into it. > > > It does if the wave function is purely epistemic. In other words, if it is > merely a means of calculating probabilities, then the supposed 'other worlds' > do not exist. The probabilities are the probability that one, and only one, > outcome is realized for each experiment.
You've lost me here. Even if the wf is epistemic, it has no bearing on whether other branches are as real as this one or not. The MWI states that all branches are equally real. Other interpretations assert that only one branch is real, because... (fill in the blanks). > > > > > > > > > and it also has to > > > make some assumptions about probability that are equivalent to > just > > assuming > > > the Born Rule. So the idea that it does not make any further > assumptions > > beyond > > > the Schrodinger equation is something of a pipe dream. > > > > > > > You need to assume something like the Kolmogorov axioms of > > probability anyway, but these are by and large definitional. > > > > For the rest, the Gleason theorem really does the heavy lifting. > > > > > > But one somehow has to relate the amplitudes of the wave function basis > vectors > > to the probabilities. And since the Schrodinger equation is > deterministic, > > introducing a probability interpretation is problematic. > > > > I never followed that line of argument. I know you've raised this > multiple times over the years, but it made little sense to me. > > For example - in classical statistical physics, the connection between > entropy and the classical microstate is statistical in nature. The > assumed deterministic nature of classical microphysics does not > prevent a probabilistic interpretation of the macrophysics. On your > line of argument, you'd need to reject Boltzmann's H-theorem. > > > But in the classical statistical mechanics case one relies on an ignorance > interpretation of probability. This is not available in the quantum case > because, given the SE, nothing is unknown.This has been discussed at length in > the literature on the philosophy of quantum mechanics. > > One problem with the probability interpretation is that the SE is insensitive > to the amplitudes -- you get the same set of worlds for an amplitude of 0.001 > as for an amplitude of 0.9. > I have seen various arguments along those lines, but found them unconvincing, and to be frank confusing. They are along the lines of "the probability of Knight's Choice winning the Melbourne cup in 2025 is either 1 or 0, because either it will happen or it won't". That is not exactly a useful notion of probability. -- ---------------------------------------------------------------------------- Dr Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders [email protected] http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/ZzpuZ_6RYFZzCJNO%40zen.
