On Friday, April 27, 2018 at 5:38:38 AM UTC, [email protected] wrote: > > > > On Friday, April 27, 2018 at 5:10:46 AM UTC, Brent wrote: >> >> >> >> On 4/26/2018 9:24 PM, [email protected] wrote: >> >> >> >> On Friday, April 27, 2018 at 1:43:30 AM UTC, Brent wrote: >>> >>> >>> >>> On 4/26/2018 6:21 PM, [email protected] wrote: >>> >>> >>> >>> On Friday, April 27, 2018 at 1:10:25 AM UTC, Brent wrote: >>>> >>>> >>>> >>>> On 4/26/2018 4:14 PM, [email protected] wrote: >>>> >>>> >>>> >>>> On Thursday, April 26, 2018 at 10:25:29 PM UTC, Brent wrote: >>>>> >>>>> >>>>> >>>>> On 4/26/2018 2:33 PM, [email protected] wrote: >>>>> >>>>> >>>>> >>>>> On Thursday, April 26, 2018 at 9:09:48 PM UTC, Brent wrote: >>>>>> >>>>>> >>>>>> >>>>>> On 4/26/2018 7:23 AM, [email protected] wrote: >>>>>> >>>>>> >>>>>> >>>>>> On Thursday, April 26, 2018 at 4:12:41 AM UTC, Brent wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 4/25/2018 7:44 PM, [email protected] wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Thursday, April 26, 2018 at 2:17:31 AM UTC, Brent wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On 4/25/2018 6:39 PM, [email protected] wrote: >>>>>>>> >>>>>>>> >>>>>>>> *On its face it's absurd to think the SoL is invariant for all >>>>>>>> observers regardless of the relative motion of source and recipient, >>>>>>>> but it >>>>>>>> has testable consequences. The MWI has no testable consequences, so it >>>>>>>> makes no sense to omit this key difference in your historical >>>>>>>> comparisons >>>>>>>> with other apparent absurdities in physics. Moreover when you factor >>>>>>>> into >>>>>>>> consideration that non locality persists in the many worlds postulated >>>>>>>> -- >>>>>>>> assuming you accept Bruce's analysis -- what exactly has been gained >>>>>>>> by >>>>>>>> asserting the MWI? Nothing as far as I can tell. And the loss is >>>>>>>> significant as any false path would be. AG* >>>>>>>> >>>>>>>> >>>>>>>> It's one possible answer to the question of where the Heisenberg >>>>>>>> cut is located (the other is QBism). It led to the theory of >>>>>>>> decoherence >>>>>>>> and Zurek's theory of quantum Darwinism which may explain Born's rule. >>>>>>>> >>>>>>>> Brent >>>>>>>> >>>>>>> >>>>>>> * I've always found the Heisenberg Cut to be a nebulous concept, a >>>>>>> kind of hypothetical demarcation between the quantum and classical >>>>>>> worlds. * >>>>>>> >>>>>>> >>>>>>> That's the problem with it; it doesn't have an objective physical >>>>>>> definition. Bohr regarded it as a choice in analyzing an experiment; >>>>>>> you >>>>>>> put it where ever was convenient. >>>>>>> >>>>>>> *What kind of boundary are we talking about, and how could the MWI >>>>>>> shed any light on it, whatever it is? AG * >>>>>>> >>>>>>> >>>>>>> In MWI there is no Heisenberg cut; instead there's a splitting of >>>>>>> worlds which has some objective location in terms of decoherence. >>>>>>> >>>>>>> Brent >>>>>>> >>>>>> >>>>>> The Heisenberg Cut is too vague and ill-defined to shed light on >>>>>> anything, and to say the MWI is helpful is adding another layer of >>>>>> confusion. AG >>>>>> >>>>>> >>>>>> Decoherence is a specific well-defined physical process and it >>>>>> describes the splitting of worlds. There is still some question whether >>>>>> it >>>>>> entails the Born rule, but at worst the Born rule remains as a separate >>>>>> axiom. >>>>>> >>>>>> Brent >>>>>> >>>>> >>>>> Let's say an electron goes through an SG device. IIUC, its spin state >>>>> becomes entangled with the spin wf's of the device. How do you infer >>>>> splitting of worlds from this? AG >>>>> >>>>> >>>>> I don't. Why should I? >>>>> >>>>> Brent >>>>> >>>> >>>> I could swear that you wrote above that decoherence describes the >>>> splitting of worlds, so I gave you an example of decoherence >>>> >>>> >>>> You didn't give an example of decoherence. Where's the decoherence in >>>> an electron flying through a divergent magnetic field? >>>> >>>> Brent >>>> >>> >>> That's what I figured you would write and maybe you're correct. I >>> thought decoherence means that the wf of the system being measured, gets >>> entangled with the wf's of the environment, in this case the SG device. Why >>> is this not decoherence, and if it isn't, what is? TIA, AG >>> >>> >>> Decoherence happens when the particle is detected in one path or the >>> other, not when going thru the SG. It's a classic experiment to show that >>> particle wf can be coherently recombined after going through SGs. So if >>> you set up a detector on one leg of the SG then the world splits when there >>> is a detection vs no detection. >>> >>> Brent >>> >> >> I am not considering a singlet state; just an electron passing through a >> SG device and being measured, spin up or down. Are you saying no >> decoherence in this case? >> >> >> No. I just saying when you posed the problem you didn't say anything >> about detection. You just said an electron went through an SG apparatus. >> >> From what I gather from descriptions of decoherence, it occurs when a >> measurement occurs, and the particle's wf gets entangled with the >> measurement device. This is a detection, and I think you're saying the >> world splits. If so, why would it? If there's no detection for whatever >> reason, what are we to conclude? I would guess, nothing. AG >> >> >> No. The world still splits because no-detection means the particle took >> the other path where there was no detector, at least that's the MWI >> theory. >> > > *Can't no detection just mean an inefficient measuring device? AG* > > >> This is confirmed by the buckyball Young's slit experiment. The >> interference pattern disappeared even though the IR photons weren't >> measured. >> >> You've been around these lists for years. Haven't you read these >> experiments? >> >> Brent >> > > > *Just SG, not Buckyball. Not sure what Buckyball proves. You have an > interference pattern when it goes through slit, and no IR photons detected. > What does one thing have to do with another? Sorry; this is very confusing. > AG* >
I meant to write; the pattern disappears (and no IR photons detected). Don't know how to interpret the results you describe. AG > > *Earlier, this particular discussion began with your comments about the > Heisenberg Cut and you claimed it said something about splitting of worlds. > "Decoherence is a specific well-defined physical process and it describes > the splitting of worlds." If you don't believe in the MWI, how can you > claim decoherence is well defined and supports splitting of worlds? 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.
