Brent, The core of my argument is that in a single-world framework, the ensemble of possibilities described by Schrödinger’s equation is only conceptual. If only one history is realized, then those "possibilities" don’t exist in any meaningful way—they’re theoretical abstractions. In the absence of an actual ensemble from which a selection occurs, the notion of randomness is a metaphor, not a mechanism.
In the many-worlds framework, every possibility is realized, so the "selection" is an emergent phenomenon from within the structure of the totality. In the single-world view, however, there’s no actual ensemble. Probabilities merely describe the likelihood of the one realized outcome, but there’s no underlying framework where those possibilities are instantiated. Randomness then becomes a label for the lack of explanation rather than a true process. To say "the single history simply is" and call that random doesn’t resolve the issue—it just restates it. Without an ensemble that exists ontologically (even probabilistically), the idea of selection collapses because there’s nothing to select from. The photon emission you mentioned is described by probabilities in QM, but those probabilities don’t correspond to real, alternate outcomes in a single-world framework. The realized outcome is the only one that exists, and all other "possibilities" are simply unrealized ideas. In contrast, in the many-worlds interpretation, the photon’s emission in one state is one thread of the total structure, and alternate emissions exist along other threads. This gives explanatory power to the probabilities, as they correspond to real structures within the ensemble. Regarding your point that probabilities lose meaning in MWI because all possibilities are realized—that’s not the case. Probabilities in MWI are understood as the measure of the branching structure relative to the observer's perspective. They still hold meaning because they reflect the structure of the multiverse, not a singular outcome. The single-world view still strikes me as incoherent because it leans on the language of probability and possibility but denies their actual realization. Without an ensemble, it’s hard to see what randomness truly means. Quentin Le mer. 8 janv. 2025, 00:47, Brent Meeker <meekerbr...@gmail.com> a écrit : > > > > On 1/7/2025 3:05 PM, Quentin Anciaux wrote: > > AG, > > > > The issue isn’t just that true randomness is unintelligible; it’s that > > in a single-world framework, there is no such thing as true > > randomness. Randomness implies a selection from a set of > > possibilities, but if only one world exists, there is no set—only the > > one outcome. Without an ensemble of possibilities, the concept of > > randomness collapses. > But there are an ensemble of possibilities. That's what Schroedinger's > equation tells us, for example an atom has an ensemble of possible > energy states. And when one of them emits a photon, it is a random > realization of a possibility. > > There’s no mechanism, no process, no "roll of the dice." The single > > history simply is, with no justification for why it is this and not > > something else. > Exactly why is is random. > > > > In contrast, randomness in frameworks like QM operates within a > > structure where multiple possibilities exist, even if only > > probabilistically. > In a single-world framework there are multiple possibilities that "exist > probabilistically" (where I take that to mean have greater than zero > probability). The world consists of a the realization of possibilities. > > But a single-world theory denies the existence of any ensemble. > It doesn't deny the existence in the probabilistic sense you posited. > > > It renders the idea of “random selection” meaningless because there’s > > nothing to select from. > Sure there is. It's random selection from the possibilities. > > > This isn’t about whether randomness has rules; it’s about whether the > > concept of randomness even applies when there’s only one realized > > possibility for all eternity. > That's always true of randomness. There's only one realized > possibility. If all possibilities were realized probability has no > meaning...which in fact a problem for MWI. > > > > This is why I find the single-world framework fundamentally > > incoherent. It doesn’t just lack explanatory power—it undermines the > > very concepts it relies on to describe itself. > I explains why the universe is not simply a clockwork machine as Newton, > Laplace, Lagrange, etc conceived it. A universe in which the whole > future was already written on the first page. > > 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 everything-list+unsubscr...@googlegroups.com. > To view this discussion visit > https://groups.google.com/d/msgid/everything-list/72956e43-87d1-45fe-81b9-164f24bda7a7%40gmail.com > . > -- 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 everything-list+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAMW2kAqN4Nz2LFMykbC6P8GifducLVzoB1y4Au%2B0dYpv9ML6hg%40mail.gmail.com.
