On Tuesday, June 12, 2018 at 11:03:28 PM UTC, Bruce wrote: > > From: <[email protected] <javascript:>> > > > *Doesn't the superposition of states used in the cat problem. or indeed >> any quantum superposition, requires the system being measured to be >> isolated? AG * >> > > *As I see it, the total system represented by the wf ( (Alive, Undecayed) > + (Dead, Decayed) ), leaving out Dirac symbols, must be isolated if it's > regarded as a superposition. If so, this implies the cat is also isolated. > AG* > > > That is the root of your problem in understanding superpositions. There is > absolutely no requirement for the system to be isolated in order for there > to be a superposition. In fact, the opposite is the case -- each branch of > the superposition decoheres by interacting with, and becoming entangled > with, the environment. That is how quantum measurement theory proceeds. > Isolation from the environment is a condition you made up, and it is not > required. > > Bruce >
For reasons not worth explaining, I have had doubts whether a superposition requires isolation. But what it does require, at least in the cat paradox, is interference among the components. Otherwise, Schroedinger couldn't have concluded that the superposed wf implies the cat is simultaneously alive and dead. So the issue becomes whether a macro object like a cat has a well defined wave length, which IIUC, is the necessary condition for interference. 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
