On Monday, July 16, 2018 at 8:30:58 AM UTC-6, Bruno Marchal wrote: > > > On 13 Jul 2018, at 01:55, agrays...@gmail.com <javascript:> wrote: > > > > On Wednesday, July 11, 2018 at 2:16:24 PM UTC-6, agrays...@gmail.com > wrote: >> >> >> >> On Tuesday, July 10, 2018 at 4:42:44 PM UTC-6, Brent wrote: >>> >>> >>> >>> On 7/10/2018 3:01 PM, agrays...@gmail.com 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. 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. Try this; in the case of radioactive decay, can you define the interference between Decayed and Undecayed states? 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 * > > 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 everything-li...@googlegroups.com <javascript:>. > To post to this group, send email to everyth...@googlegroups.com > <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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
