On Wednesday, July 18, 2018 at 2:00:47 AM UTC, [email protected] wrote: > > > On Tuesday, July 17, 2018 at 12:00:08 PM UTC, Bruno Marchal wrote: >> >> >> On 16 Jul 2018, at 23:08, [email protected] 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. >> > *You're mistaken. In quantum superpositions, orthogonal does not mean 90 deg out of phase -- as is the case for ordinary vectors in the plane -- but that the inner product is zero. Hence, since the inner product of all components of a superposition are mutually orthogonal, or zero, how can you claim that interference exists? AG*
> 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]. >> 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]. 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.
