On Saturday, December 16, 2017 at 6:00:30 PM UTC, John Clark wrote: > > On Thu, Dec 14, 2017 at 9:20 PM, <agrays...@gmail.com <javascript:>> > wrote: > > > >> I don't see how Wigner's friend presents a problem for Copenhagen. >> According to the CI, the wf collapses when the system measured, which is >> when the box is opened. What am I missing? >> > > > According to > > Copenhagen > > Wigner's friend > > opens the cat box and that > > collapses > > the cat's wave function, and so Wigner's friend > > now knows the cat's fate, but Wigner's friend > > is also in a box and Wigner > > himself is outside that box, so until Wigner opens his friend's box his > friend is in a "I see a dead cat" state AND a "I see a live cat state". > And of course you could put Wigner himself in a box with somebody outside > it and you could keep increasing the number of nested boxes until the > entire universe is included, and that is why the Copenhagen > > interpretation is useless if you're > interest is in > dealing in cosmology because there is nobody outside > to > universe observe it. > > And God > is of no help unless somebody knows who collapses God's wave function, > and even then there would be another unanswered question too obvious to > mention. > > John K Clark >
*Not a problem. Easily solved. Remember; a superposition of states only exists for isolated systems, and the measurement, collapse, or whatever you want to call it, occurs when the isolated system interacts with the macro environment, in this case when the box opens, or more generally when the system interacts with a macro system called 'the measuring device'. The cat problem is an idealized situation. In fact, one can never isolate a cat from its environment, but this is irrelevant for the illustrative purpose of Schrodinger's thought experiment. We don't understand the measurement process, but this doesn't justify affirming Tegmark and going off into MWI fantasies. I now tend to agree with Lawrence that the wf has no ontological status. Believing that it does has led us into fairy tale land. 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
