On Monday, April 30, 2018 at 3:33:23 AM UTC, [email protected] wrote: > > Implied by standard QM insofar as the theory is inherently irreversible, > that is, irreversible in principle at the quantum level since the wf cannot > be recovered by time reversal. AG >
I argued this conclusion on the Entanglement thread. Here I will add some additional considerations. When you think of time reversibility, say for an electron being measured by SG device, you naturally think of passing the measured electron backward along the same path, trying to recover the original wf by running time backward. Of course you can't run time backward during or even after a measurement because QM doesn't provide any time dependent equations for the measurement process. But even if you could do the thought experiment, according to QM, if the measurement was, say, spin UP, it remains spin UP by virtue of the measurement postulates of QM. Further, This MUST be the backward in time measurement result if you simply accept time symmetry, and not appeal to the measurement postulates of QM. Thus, it seems highly plausible that the original wf, a superposition, cannot be recovered after the measurement, and that QM is a time IRREVERSIBLE theory. 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.
