On Tuesday, May 1, 2018 at 3:30:31 PM UTC, Brent wrote: > > > > On 5/1/2018 12:40 AM, [email protected] <javascript:> wrote: > > > > On Tuesday, May 1, 2018 at 6:57:14 AM UTC, scerir wrote: >> >> *AG: 'I suppose people will appeal to entanglement and decoherence to try >> to make sense of how a measurement occurs. Nevertheless, I tend strongly >> to the view that the theory is inherently irreversible; that is, TIME >> IRREVERSIBLE IN PRINCIPLE If so, it implies the arrow of time has its >> origin at the quantum level.'* >> >> #### Maybe. >> >> But ... since we say that there is non-separability between >> (position/momentum or time/energy) entangled quantum states, can we also >> say there is quantum non-separability not just *in space* (i.e. correlation >> between space-like separated events) but also *in time* (there is no >> *causal* ordering)? >> >> Are there Bell's inequalities for correlations *in time*? s. >> > > Sure. Just make the measurements at time-like separate events. It's not > so interesting because then there could be a local (slower than light) > hidden variable that would explain the result. > > https://arxiv.org/abs/1712.06884 >> >> https://arxiv.org/abs/1708.00248 >> > > *If two events are space-like separated, I think it's correct to say there > is no causal ordering. However, when analyzing time reversal for > measurements -- whether or not it exists in QM -- aren't we dealing with > time-like ordering in the laboratory wherein the "first" measurement > occurred? AG* > > > > Spacelike events have no time order. Their order varies depending on your > choice of coordinate system. > > Brent >
*Right; that's what I wrote above. But it isn't obvious, and might not be the case, that ascausal ordering, aka space-like separation, comes into play when doing a thought experiment on reversing a quantum measurement. Why would it, how could it come into play? 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.
