On Saturday, April 28, 2018 at 9:33:58 PM UTC, Brent wrote: > > > > On 4/28/2018 9:39 AM, [email protected] <javascript:> wrote: > > Is it a settled issue whether measurements in QM are strictly > > irreversible, > > There are interactions that, if you did not arrange that they be erased, > would constitute measurements. Whether you say they were measurements > and then got erased or they are not measurments because they didn't > produce an irreversible record is a phlosophical or semantic question. > > > that is irreversible in principle, or just statistically irreversible, > > that is, reversible but with infinitesimal probability? TIA, > > The equations are all reversible so you might say they are reversible > with infinitesimal probability...but in most cases that reversal would > mean catching and reversing photons that are already on their way > outbound beyond the orbit of the Moon. > > Brent >
Are there any measurements that can't be reversed regardless of the fact that the equations of physics are time reversible? I could swear, and I DO, that Bruce demonstrated such a case for spin 1/2 particles measured by SG device. 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.
