On Tuesday, July 17, 2018 at 12:00:08 PM UTC, Bruno Marchal wrote: > > > On 16 Jul 2018, at 23:08, [email protected] <javascript:> wrote: > > > > On Monday, July 16, 2018 at 8:30:58 AM UTC-6, Bruno Marchal wrote: >> >> >> On 13 Jul 2018, at 01:55, [email protected] wrote: >> >> >> >> On Wednesday, July 11, 2018 at 2:16:24 PM UTC-6, [email protected] >> wrote: >>> >>> >>> >>> On Tuesday, July 10, 2018 at 4:42:44 PM UTC-6, Brent wrote: >>>> >>>> >>>> >>>> On 7/10/2018 3:01 PM, [email protected] wrote: >>>> >>>> *IIRC, the above quote is also in the Wiki article. It's not a coherent >>>> argument; not even an argument but an ASSERTION. Let's raise the level of >>>> discourse. It says we always get a or b, no intermediate result when the >>>> system is in a superposition of states A and B.. Nothing new here. Key >>>> question: why does this imply the system is in states A and B >>>> SIMULTANEOUSLY before the measurement? AG * >>>> >>>> >>>> Because, in theory and in some cases in practice, there is a direct >>>> measurement of the superposition state, call it C, such that you can >>>> directly measure C and always get c, but when you have measured and >>>> confirmed the system is in state c and then you measure A/B you get a or b >>>> at random. The easiest example is SG measurements of sliver atom spin >>>> orientation where spin UP can be measured left/right and get a LEFT or a >>>> RIGHT at random, but it can be measured up/down and you always get UP. >>>> Any >>>> particular orientation can be *written* as a superposition of two >>>> orthogonal states. >>>> >>> >>> *When you're trying to explain esoteric issues to a moron in physics, >>> you need to be more explicit. These are the issues that cause confusion and >>> caused me to fail to "get it". After some subsequent posts, you seem to be >>> saying that in an SG spin experiment where the measurement base is UP/DN, >>> the system being measured is ALSO in a superposed LEFT/RIGHT state which is >>> also measured (by an SG device designed to measure spin?), and that the >>> LEFT/RIGHT superposed state persists with some persistent eigenvalue after >>> UP/DN is measured. It's murky for us morons. How does one get the system >>> to be measured in a superposition of RIGHT/LEFT; what is the operator for >>> which that superposition is an eigenstate, and what is the value of the >>> persistent eigenvalue?* >>> >>> *Furthermore, you finally assert that since the RIGHT/LEFT state >>> persists -- meaning that particle is in some DEFINITE state after the spin >>> is measured -- and since (as you finally, finally assert) that that state >>> can be written as a superposition of UP/DN, all is well -- in the sense >>> that we can now be certain that the system is physically and simultaneously >>> in the UP and DN states (which I am claiming is a fallacy). * >>> >>> *HOWEVER, assuming that I understand your argument after filing the gaps >>> in your presentation (and pointing to some unanswered issues), I now must >>> "rant" again that the UP/DN superposed representation is NOT unique. Thus, >>> since there are finitely many or uncountable many such representations, and >>> since (as per LC) QM has no preferred basis, your argument for the physical >>> simultaneity of UP and DN states fails. I mean, I could write the >>> superposed states in the basis (UP + DN) and (UP - DN), or in many other >>> bases. Absent uniqueness of bases, one cannot assert that the system is >>> physically and simultaneously in any particular pair of basis vectors.* >>> >>> *AG* >>> >> >> *I've been looking over your references to Peres. CMIIAW, but AFAICT he >> doesn't deal with the issue I have been "ranting" about; namely, the >> non-uniqueness of bases, implying IMO that the concept of simultaneous >> physical states of the components of a superposition is an additional, >> unsupported assumption of QM which leads to some popular misconceptions of >> what QM is telling us. * >> >> >> >> Then you need to find a new explanation of the interference that occurs >> in basically all quantum experiments, like the two slits, the statistics of >> results with Stern-Gerlach spin measuring apparatus, etc. >> > > *I am not trying to explain the interference. * > > > You should. That is the whole problem. How can we get interference if the > wave describes only our knowledge state. The reason why we consider the > wave physically real is that the wave interfere, even the wave associate to > a single particle. > > > > *Rather I am pointing out an unnecessary assumption that leads to > paradoxes.* > > > ? > > > > > * See comment below. AG* > > >> The whole point of the physical wave amplitudes is that the diverse >> superposed components have a physical role, through destructive or >> constructive, or in between, interference. >> > > *The amplitudes give probabilities of occurrence, confirmed by > measurements. Nothing more. You forget that the components of the > superposition are usually assumed to be orthogonal states, which don't > mutually interfere. Thus, you are claiming to explain interference from > component states which don't interfere. * > > > That is what we do with any wave, and there is no problem there. It just > that cos(pi/2) is zero. > The problem here is that the amplitude of the wave, when squared, give a > probability to find a particle somewhere, but this forced us to make the > wave physical, as it will behave differently if there is two slits, one > splits, etc. > > > > > > *Try this; in the case of radioactive decay, can you define the > interference between Decayed and Undecayed states? AG* > > > It is not relevant. I prefer ro use superposition of spin, than a temporal > phenomenon. >
*OK, then use superposition of spin and describe the interference. Note that since the Up and Dn are orthogonal, there is no interference. That is, generally, when we write a superposition where the components are eigenstates, it is assumed the components are mutually orthogonal, hence no interference. AG* > > >> Note that the discussion here supposed the quantum theory, but you are >> free of course to propose an alternative. Many have tried without success, >> though. >> > > *What I am doing is asking the usual suspects the basis for the assumption > that the components of a superposition physically exist simultaneously. So > far, IMO, their silence is pregnant. They can't. AG * > > > > Then explain me what happens in the two slit experiments, when we send the > particles “one by one”. > You need superposition to explain this. It is the base of QM: particles > dynamics are described by waves, and those wave do superpose and interfere, > even when the particles are alone. > *I don't have to explain everything, and in fact I cannot. All I want to know is how can there be interference among components of a superposition, when they are mutually orthogonal. AG * > > Bruno > > > > > > >> Bruno >> >> >> >> >> >> *Incidentally, when you earlier referred to a RIGHT/LEFT superposition, >> did you mean circular polarization, or right and left directions in a SG >> apparatus in relation to Up/Dn measurements? TIA, AG * >> >>> >>>> This is true in general. Any state can be written as a superposition >>>> of states in some other basis. But it is not generally true that we can >>>> prepare or directly measure a system in any given state. So those states >>>> we can't directly access, we tend to think of them as existing only as >>>> superpositions of states we can prepare. >>>> >>>> Brent >>>> >>> >> -- >> 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. >> >> >> > -- > 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] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > 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.
