Le sam. 15 févr. 2025, 02:49, Brent Meeker <[email protected]> a écrit :
> > > On 2/14/2025 4:55 AM, John Clark wrote: > > On Fri, Feb 14, 2025 at 12:13 AM Brent Meeker <[email protected]> > wrote: > >> > >> *>> Schrodinger's equation produces a complex-valued wave that evolves in >>> time, the square of the absolute value of the amplitude of that wave >>> determines probabilities. You just take the Born Rule as a given because >>> experimenters tell you that it works. Many Worlds can tell you why it works >>> and why you need it.* >> >> >> *> So you say. But all attempts to derive it, assuming MWI, have failed.* >> > > *I admit there is some controversy concerning the validity of the > derivations of the Born Rule that Many Worlds advocates have come up with, > but they are the only ones that have even tried. Copenhagen, Objective > Collapse, the Bayesian Interpretation and of course Shut Up And Calculate > haven't even tried to derive it from their respective interpretations, they > just accept the Born Rule as a starting assumption. * > > You said you read the papers by Brandes, Weinberg, and Pearle to which I > posted links. That's exactly what they were about. Of course if you can > *only* be satisfied by an ignorance interpretation of probability, then > any one-world interpretation is going to conflict with your theology. > > > > *Deutsch and Wallace have proven that if the Many Worlds idea is correct > then a rational agent in a branching universe would bet according to the > probabilities the Born Rule produces; the only assumptions they needed is > that similar quantum states should have similar probabilities, and > probability assignments should be stable over time. But some complain that > they have not defined "rationality" with enough mathematical rigor. * > > *And in 2014 Sean Carroll and Charles Sebens used Many Worlds to find > another derivation of the Born Rule based on self‐locating uncertainty. > However some complain that if you know the full wave function then you > should not have any uncertainty at all; I believe that complaint is invalid > resulting from confusion over the personal pronoun "you". Another complaint > is that they are assuming something called the "Epistemic Separability > Principle", the idea that an observer’s credences about local measurements > shouldn’t be affected by distant changes in the environment; I can't > comment further about that because I don't know what the hell it means.* > > * >> Many Worlds says everything always obeys Schrodinger's equation >>> including the observer, therefore there will always be self-location >>> uncertainty, it can't be avoided.* >> >> Fallacious reasoning. There won't be any self-location uncertainty if > only one world happens...as a properly interpreted Schroedinger plus Born > rule says. > Yes, and there wouldn't be any if the Earth were flat, either. But that doesn’t mean reality conforms to the simplest assumption. The fact remains: quantum mechanics, as it stands, predicts self-location uncertainty unless you introduce an ad hoc collapse mechanism. > > > *< And how does that result in uncertainty, when you are located in every >> branch. * >> > > *Brent Meeker is in every branch but Mr.You is in only one branch, and > until Mr.You opens the box and looks at the cat Mr.You lacks sufficient > information to know which branch Mr.You is in. If personal pronouns had > never been invented the Many Worlds idea would have been universally > accepted by the physics community 50 years ago. * > > > A semantic solution to a physics problem? > No, a recognition that "where am I in the wavefunction?" is a valid physical question. Ignoring it doesn’t make it go away. Quentin > > Brent > > -- > 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/7851da3c-c45c-406b-9757-ba137a66a608%40gmail.com > <https://groups.google.com/d/msgid/everything-list/7851da3c-c45c-406b-9757-ba137a66a608%40gmail.com?utm_medium=email&utm_source=footer> > . > -- 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/CAMW2kAq9g0WWaoNnCO2cQ22LQsNJRw34RqDogP3PPaFxmRO%3DHg%40mail.gmail.com.
