> Il 27 maggio 2018 alle 8.21 'scerir' via Everything List > <[email protected]> ha scritto: > > > > > > > Il 27 maggio 2018 alle 6.05 Brent Meeker <[email protected]> > ha scritto: > > > > > > > > On 5/26/2018 1:37 PM, [email protected] > > mailto:[email protected] wrote: > > > > > > > > > > > > > On Saturday, May 26, 2018 at 5:08:51 AM UTC, Brent wrote: > > > > > > > > > > > > > > > > > > On 5/25/2018 9:50 PM, [email protected] wrote: > > > > > > > > > > > > > Right. I was just making the observation > > > > that when we don't see advanced EM waves (coming from the future?), > > > > it's generally not seen as a big deal and they're ignored. But when > > > > decoherence or the MWI implies the creation of full-blown worlds (that > > > > we can't observe), there seems to be a large body of opinion that > > > > accepts this bizarre result without serious criticism that there's no > > > > mechanism or process for creating full-blown worlds. No. I don't > > > > believe in such worlds. I tend to think a large segment of professional > > > > physicists have gone mad. AG > > > > > > > > > > > > > > Except you've got it > > > > > backwards. There is a mechanism and process for creating them FAPP, > > > > > evolution by the Schroedinger equation, which is the same process > > > > > used in predicting results. But there is no physical mechanism for > > > > > making them disappear....there's a mathematical process, i.e. taking > > > > > the partial trace which is the same as applying a projection operator > > > > > (with a little better justification). > > > > > > > > > > > > > > There's a distinction between subspaces that are disjoint and > > > inaccessible to each other, and their non existence. Apparently you want > > > to make the case that their mutual inaccessibility is equivalent to their > > > non existence. > > > > > > > > Operationally, it is. > > > > Brent > > > > > Sometimes the principle of conservation of quantum information > > (no-cloning, no-deleting) seems to have something to do with MWI - > > conservation of quantum information and "relative state" formulation both > > depend on linearity( ?) - in the sense that any other world must be > > inaccessible (just to conserve quantum information). > > s. > > "In conclusion, we have shown that any theory for which dynamics is > linear with respect to stochastic mixing, the no-cloning and no-deleting > principles follow from the law of conservation of information, and from > whether two copies contain a different amount of information than a single > copy. In particular, this result allows us to understand the physical reason > for which perfect cloning or > deleting are impossible. They are forbidden because they infringe a > principle of conservation of information. Classically, two copies and one > copy contain the same information. However in the quantum case, these > information contents are generically different, putting restrictions on > cloning and deleting processes." > > https://arxiv.org/abs/quant-ph/0407038 > https://arxiv.org/abs/quant-ph/0407038 > > see also, for entropy issues, https://arxiv.org/abs/quant-ph/0306044 >
"Considering no-cloning and no-deleting together (and excluding wavefunction collapse as a valid physical process) we see that quantum information (of non-orthogonal states) has a quality of “permanence”: creation of copies can only be achieved by importing the information from some other part of the world where it had already existed; destruction (deletion of a copy) can only be achieved by exporting the information out to some other part of the world where it must continue to exist." -Jozsa in https://arxiv.org/abs/quant-ph/0204153 > > > > > > > > > > > -- > > 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] > > mailto:[email protected] . > > To post to this group, send email to > > [email protected] mailto:[email protected] . > > Visit this group at https://groups.google.com/group/everything-list. > > For more options, visit https://groups.google.com/d/optout. > > > > > > > > > > -- > 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] > mailto:[email protected] . > To post to this group, send email to [email protected] > mailto:[email protected] . > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- 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.
