On Tuesday, October 8, 2024 at 11:21:37 PM UTC-6 Alan Grayson wrote:
On Tuesday, October 8, 2024 at 8:59:41 PM UTC-6 Brent Meeker wrote: On 10/8/2024 7:23 PM, Alan Grayson wrote: On Tuesday, October 8, 2024 at 1:35:01 PM UTC-6 Brent Meeker wrote: On 10/8/2024 4:14 AM, John Clark wrote: On Tue, Oct 8, 2024 at 5:55 AM Alan Grayson <[email protected]> wrote: *> I think I get it.* *I think you don't. * * > If you admit that Schrodinger was correct that superposition does NOT mean a system is in all states of its superposition state before measurement, then the Many-Worlds interpretation is also falsified.* *But if "**a system is in a superposition of states**" does NOT mean when"* *all states**" occur "**simultaneously**" then what the hell does it mean? Even Newton, even Aristotle, even Og the caveman, had no problem with an object being in 2 different places AT 2 DIFFERENT TIMES, what made Quantum Mechanics so revolutionary is that it seem to say that one thing could be at two different places AT THE SAME TIME. * Here's how I present it in my popular lectures. There is a range of states in a subspace "ALIVE" and another range of states in a subspace "DEAD". The cat starts out in one of the alive states and moves thru series of superpositions from ALIVE to DEAD, the dark red dotted line. These are not different simple conditions of the cat; they are different *probability amplitudes* corresponding to the cat's state. The physical state of the cat is a vector in this Hilbert space, but it is very much more complicated, and I've collected all that complication into "OTHER VARIABLES". So the state of the cat evolves along the magenta dotted line, which projects onto the simpler dark red dotted line. *But since Schrodinger idealizes a physical reality, where there is no continuous evolution of the Cat from Alive to Dead, I don't see this as an explanation or refutation of the lesson Schrodinger tried to offer about superposition. AG* I often see it written that "Before measurement, the system is not in any definite state." But I think this is misleading. The system is in a definite state, it's just not a state for which we have an operator that would return that state as an eigenstate. Brent *Without an eigenstate for the Cat's state, it's dubious whether Schrodinger's thought experiment is valid within the context of QM, and moreover, whether QM can be applied to macro objects which also have no obvious eigenstates. * *Some completely isolate object may be quantum mechanical and macro...but that's essentially impossible to arrange.* *But the SG experiment does seem to indicate, along with Bell experiments, that it's possible for a superposition to be valid where its constituents are all NOT pre-existing states. Do you agree with this latter conclusion, * What is it a superposition *OF*, if not pre-existing states? *It could just be a summed list of possible outcomes, a pure vanilla interpretation using a postulate of QM, and called, confusingly, "the state of the system", with the measurement determining/forcing a particular outcome. Isn't this a legitimate interpretation of the superposition of spin states for the SG experiment? This seems reasonable since all wf has to do, is participate in the calculation of probabilities. TY, AG* The formulation I object to is saying that "It's not in any definite state, not even in a superposition of states". To say a superposition be "valid" is strange terminology. I don't know what it could mean except that the object was in a coherent mixture of two different states. i.e. a superposition. *If you don't mind, could you please define "a coherent mixture of two different states." TY, AG* 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 on the web visit https://groups.google.com/d/msgid/everything-list/64f48b3b-8557-47a2-941d-1abebaeac0ben%40googlegroups.com.
