On Wed, Feb 26, 2025 at 10:26 PM Quentin Anciaux <[email protected]> wrote:
> You are still assuming that each measurement results in a discrete split > with exactly one observer per branch, which is an interpretation, not a > derivation. Nothing in the Schrödinger equation forces branches to be > discrete rather than continuously superposed structures with relative > measure. Your reasoning assumes what it wants to prove: that branching is a > countable process rather than a differentiation of an already superposed > structure. > I find it interesting that you haven't even attempted to answer the detailed argument that I made (below). That, to me, suggests that you do not have any coherent response to offer. So you just repeat your normal smoke-and-mirrors trick and hope that I will be diverted away from the main points. I think you need to up your game if you want to make any progress here. Bruce > Publish it, what are you afraid of? Being proved wrong? > > Quentin > > Le mer. 26 févr. 2025, 11:04, Bruce Kellett <[email protected]> a > écrit : > >> On Wed, Feb 26, 2025 at 7:08 PM Quentin Anciaux <[email protected]> >> wrote: >> >>> >>> You’re still misrepresenting the argument. It’s not branch counting >>> under another name, it’s about how measure determines observer frequencies. >>> The issue is whether the number of observer instances scales with amplitude >>> squared, not whether we simply count branches. If all branches were >>> weighted equally, MWI would have been dead on arrival, because it wouldn’t >>> match experiments. >>> >>> The claim that “one observer per branch” is a direct consequence of >>> unitary evolution is just an assumption, it’s not something derived from >>> the Schrödinger equation. >>> >> >> It is derived from that, or the Schrodinger equation enhanced with >> unitary evolution and the linearity of Hilbert space. >> >> Since you clearly don't get it. Let me spell it out in baby steps. >> >> We start from the wave function for some system, say |psi>. This is the >> expanded in some basis like |psi> = a|0> + b|1>, where I have taken a two >> dimensional space for clarity and convenience, although the argument is >> easily expanded to an arbitrary number of independent basis states. >> >> We then measure this state (or subject it to some interaction). >> |psi>|O>|E> where |O> is an observer, and |E> is the environment which can >> include anything else that is relevant. Linear unitary evolution then >> entangles both the observer and the environment with the object state: >> >> |psi>|O>|E> = (a|0> + b|1>)|O>|E> --> a|O sees zero>|E records >> zero>|0> + b|O sees one>|E records one>|1>, >> >> One can readily see that there is one, and only one, copy of the observer >> for each branch. Decoherence renders these branches approximately >> orthogonal, and leads to the notion of independent worlds. The argument >> can, of course, be readily generalized to a state with any number of basis >> vectors. In no case, do we get more than one copy of the observer on any >> branch, and there are no branches without a copy of the observer. >> >> All of this is just elementary linear unitary evolution, taught in >> general quantum mechanics courses. If you want to deny this, you have to go >> to some other theory which is incompatible with quantum mechanics. >> >> 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/CAFxXSLQGreXJZ01ukTV5PJSnM9g8QpRdhTmcog3Hz1rHoA%2BkHw%40mail.gmail.com.
