On Monday, November 18, 2024 at 7:38:22 PM UTC-7 PGC wrote:
On Monday, November 18, 2024 at 11:37:16 PM UTC+1 Brent Meeker wrote: On 11/18/2024 5:53 AM, John Clark wrote: ... *The useful role that Many Worlds provides is that it doesn't need to explain what a "measurement" or an "observer" is* LOL. You just wrote three paragraphs immediately above each of which referred to "observed". So if it doesn't need an explanation it must be obvious and have the same meaning as in the neo-Copenhagen interpretation, NCI. MWI needs to explain how and when the worlds split, presumably due to decoherence although I've not seen an explicit calculation of an instance of the process. The same when and how is available to NCI if you think it needs one. I find myself seeking clarification regarding your statements, Brent. E.g. about the absence of explicit calculations for the process of branching in MWI. This surprises me, as the phenomenon of decoherence, as you well know, has been extensively studied both theoretically and experimentally. The literature is abundant with models demonstrating how interactions between quantum systems and their environments suppress interference, leading to the emergence of classical behavior. These calculations provide the empirical foundation for many interpretations of quantum mechanics, including MWI. If your critique is that these calculations do not explicitly prove the branching described by MWI, I would consider that a valid philosophical concern, but not necessarily a deficiency of the calculations themselves, which are separate and agnostic regarding interpretation. In MWI, branching is not an additional mechanism; rather, it is a natural interpretation of decoherence. Each "world" corresponds to a term in the wavefunction that no longer interferes with others due to environmental entanglement. This framework aligns with the unitary dynamics of quantum mechanics, avoiding the need for collapse mechanisms. While it is true that some explanations use terms like "observed," MWI does not treat observation as a special ontological event. Instead, observation is modeled as a unitary interaction between systems that results in decoherence, creating branches of the wavefunction corresponding to different outcomes. In this sense, "observation" in MWI is a descriptive shorthand for the branching process and not an additional mechanism requiring explanation. Your insistence that MWI needs to explain "how and when worlds split" is strange to me; the splitting is continuous and governed by the dynamics of decoherence. Decoherence calculations, as I understand them, apply equally to MWI and other interpretations, such as the neo-Copenhagen interpretation (NCI). The question, then, seems here, in this thread, to be whether one views the wavefunction as a real entity describing multiple branches, as in MWI, or as an epistemic tool requiring collapse, as in NCI. From my perspective, MWI avoids introducing additional ad hoc elements, providing a simpler and more frugal, low cost explanation of the same phenomena. If you find the connection between decoherence and MWI unsatisfactory, it would be helpful to understand where you believe the explanatory gap lies. Scholars like Zeh, Tegmark, and Wallace have elaborated on these connections; and Schlosshauer’s reviews, in particular, provide an agnostic mathematical context for decoherence —a context on which there seems to be broad agreement in the field. And yet, I feel this is all obvious to you. Your perspective on how these studies/literature might then fall short of addressing your concerns would clarify. What am I missing, besides a lifetime of more reading and the beans to sustain the same? IMO, fundamentally, for you the bottom line is "taste". Presumably, you feel the MWI is in good taste so you affirm it. For me, it's the opposite. MWI IMO is in bad taste, very bad taste. Have you ever watched how an ant moves, or flying insects? They zig-zag, back and forth, sometimes in small circles. Presumably, every slight change creates new worlds according to the MWI, and copies of these insects come into being in these worlds. And what about us humans? Are we also in these worlds? If not, where is the cutoff? How does that come to be? It all seems totally ridiculous, indeed UGLY. You write eloquently, with authority, very educated. Probably a professor somwhere, at some prestigious university. So it baffles me how you could arrive at, and support a theory which utterly fails the smell test. But what could I know? After all, I'm just a simple country lawyer. AG -- 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/0a757039-530a-4c45-91ba-00c73d3d3d3cn%40googlegroups.com.
