Bruce, You claim that your argument proves MWI is inconsistent with the Born rule, but what you’ve actually shown is that naive branch counting doesn’t work, something Everettians already acknowledge. The real question is whether measure, derived from amplitudes, determines observer frequencies, and your argument does not disprove that.
Decoherence is not about making branches "disappear", it’s about preventing interference, which allows classical-like behavior to emerge. If low-amplitude branches exist but do not significantly contribute to observer experiences, that’s exactly what would give rise to Born-rule statistics. Your response doesn’t refute this; it simply denies that amplitudes matter beyond formal calculations, which contradicts all of quantum theory outside of measurement. You state that unitary evolution directly leads to "one observer per branch," but that’s an assumption based on a discrete branching picture that Everett himself didn’t use. The wavefunction remains continuous, and what we call "a branch" is just an approximation of decoherence-selected states. If you believe the Born rule must simply be assumed rather than derived, then fine, but that applies to all interpretations, not just MWI. If you claim MWI is falsified, then demonstrate why no derivation of the Born rule from unitary evolution is possible, instead of repeating that it hasn’t been done. And if your so-called "proof" is airtight, publish it, surely the physics community will be thrilled to see a definitive refutation of MWI. But you won’t, because you know it’s flawed. Instead, you’d rather sit here, dismissing any disagreement as stupidity while avoiding any real engagement with the open question. You’re not debating in good faith, you’re just clinging to your priors and throwing insults at those who don’t share them. If you’re so convinced of your argument, be decent enough to confront it with actual peer review instead of just parading it around this list. Or is that too much to ask? Quentin Le mer. 26 févr. 2025, 00:01, Bruce Kellett <[email protected]> a écrit : > > On 2/24/2025 6:09 PM, Quentin Anciaux wrote: >> >> Bruce, >> >> Your response assumes that unitary evolution inherently produces "one >> observer per branch" in a discrete way, but that’s not what follows from >> the wavefunction’s continuous structure. Everett’s relative state >> formulation does not propose discrete worlds but rather an evolving >> superposition where decoherence prevents interference. The fact that we >> describe macroscopic branches as "splitting" is a convenient approximation, >> not a fundamental aspect of the theory. >> >> > Everett did not know about decoherence. That idea emerged only about30 > years after Evefrett's work. > > The key point you keep ignoring is that amplitudes are not just "carried >> along" without meaning—they define the structure of the wavefunction, and >> decoherence prevents low-amplitude branches from significantly contributing >> to observer experiences. >> >> > That is simply nonsense. Decoherence does no such thing. You just keep on > making things up, and you are not arguing for Everettian QM at all. You are > obsessed by your own half-baked ideas about computationalism. > > >> Your claim that "one observer per branch" follows directly from unitary >> evolution is an assumption, not a derivation. >> >> > No, it is a straightforward derivation from the formalism. If you don't > understand that, it is just further confirmation of the fact that you > understand very little about quantum mechanics. > > > If you insist that unitary evolution cannot produce probability weights, >> then your argument applies equally to any interpretation of quantum >> mechanics. The Born rule is a fact of experiment, and any valid >> interpretation must explain it. >> >> > Why? It can just be assumed as a way to relate the theory to experimental > results. > > If you believe MWI cannot do so, you must show why—not just assert that it >> "hasn’t been done" while dismissing attempts to derive it. Assume your >> pride, publish and get the glory. >> >> > I have shown that MWI is not consistent with the Born rule. If you have > not understood the proof, then that is your lack of insight, not a failure > of the proof. > The trouble with your attempts to undermine my arguments is that you > resort to many unfounded assertions based on your half-baked > computationalist ideas. You do not argue from the basis of unitary quantum > mechanics, so your arguments are valueless. > > Bruce > > -- > 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/CAFxXSLQGsLrcL%3DgaFh-onGfOMnQnyOgT1rAvZcThx%3DsV%2BAeQ_w%40mail.gmail.com > <https://groups.google.com/d/msgid/everything-list/CAFxXSLQGsLrcL%3DgaFh-onGfOMnQnyOgT1rAvZcThx%3DsV%2BAeQ_w%40mail.gmail.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]. 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