On Friday, July 20, 2018 at 10:17:04 AM UTC, Bruno Marchal wrote: > > > On 20 Jul 2018, at 04:40, agrays...@gmail.com <javascript:> wrote: > > > > On Wednesday, July 18, 2018 at 9:24:26 PM UTC, agrays...@gmail.com wrote: >> >> >> >> On Wednesday, July 18, 2018 at 4:39:30 PM UTC, Bruno Marchal wrote: >>> >>> >>> On 18 Jul 2018, at 05:02, agrays...@gmail.com wrote: >>> >>> >>> >>> On Wednesday, July 18, 2018 at 2:00:47 AM UTC, agrays...@gmail.com >>> wrote: >>>> >>>> >>>> On Tuesday, July 17, 2018 at 12:00:08 PM UTC, Bruno Marchal wrote: >>>>> >>>>> >>>>> On 16 Jul 2018, at 23:08, agrays...@gmail.com wrote: >>>>> >>>>> >>>>> >>>>> 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 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. * >>>>> >>>>> >>>>> 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. * >>> >>> >>> >>> That is what I mean. >>> >>> >>> >>> >>> >>> *Hence, since the inner product of all components of a superposition are >>> mutually orthogonal, or zero, how can you claim that interference exists? >>> AG* >>> >>> >>> >>> A position (say at one hole) is models by a vector in an abstract linear >>> space. The position at the other hole (I’m thinking of the two slit >>> experiences) is represented by another vector. The fact that the two >>> position are distinct and distinguishable made them described by orthogonal >>> vector in that abstract linear space (an Hilbert space). >>> >> >> >> *Orthogonal vectors don't manifest interference, as shown in the simple >> case of vectors in a plane, which form a linear vector space. In the double >> slit case, there IS interference of various types along the screen, the >> components of the superposition DO interfere, but they are NOT orthogonal. >> AG * >> >> >> >>> The interference of statistics comes from the fact that the available >>> stories are described by a wave function, which describe my relative >>> ignorance on which histories I belong to. When the to holes are open, the >>> particle state might be described by a superposition of those two position, >>> which makes some angle different from PI/2, >>> >> >> *The interference, constructive, destructive, or in between, depends on >> the position of impacts and the distance between the slits. I don't deny >> interference among the (two) component terms of the superposition in this >> case. Rather, I object to the generalization of this idea to quantum >> superpositions composed of orthogonal states. AG* >> >> >>> so that interference terms can appear, and indeed can be reflected on >>> the screen by interference fringes if I repeat the experience with the same >>> wave again and again. >>> >>> >> 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. >>> >> >> *Assuming the wf gives us correct probability results, it's surely the >> case that it gives us information, what is the argument hat it also has >> physical reality, whatever that means. What does physical reality mean >> here, without resorting to your arithmetic theory? AG* >> >>> *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.* >>>> >>> >>> >>> The interferences are between waves, not state. >>> >> >> >> *We're doing Wave Mechanics, where the state functions are also called >> WAVE functions, so the interference, if it exists, is between states or >> wf's. In the case of vectors in the plane, orthogonality between two >> vectors means 90 degrees in separation. These vectors don't interfere >> because they are orthogonal -- defined as the dot product, aka, inner >> product, which is zero. So, in a quantum superposition, whether there is >> interference between the components depends on whether there is mutual >> interference as defined by the inner product. In standard QM, the >> superposition is understood, or usually written, as sums of orthogonal >> states. So no interference. Correct me if I am wrong, or if you disagree. >> AG* >> >> >> With the spin Up can be written as superpositions, like >>> >>> Up = 1/sqrt(2) Up’ + 1/sqrt(2) Down >>> Down = 1/sqrt(2) Up’ - 1/sqrt(2) Down >>> >> >> *What is Up'? So the wf for spin, which is Up + Dn (leaving out >> normalization factor) is, you now imply, 2/sqrt(2) Up'. Make no sense. >> CMIIAW. AG * >> >>> >>> The interference comes from sum and difference of such superpositions. >>> >>> Take the two “orthogonal” slits: in classical physics you can add up and >>> multiply he probabilities in the usual way for the alternatives and >>> sequence of events, but in quantum mechanics, you have an amplitude, which >>> describes a “wave of history”, and to predict the final state, you need to >>> square the amplitude, and this takes into account all path, basically >>> because (a+ b)^2 is different from a^2 + b^2. >>> >>> >>> >>> * 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 * >>>> >>> >>> I don’t really understand the language. You have interference when the >>> wave of a particle describe different outcomes possible for some observable. >>> >> >> *I think this is wrong. See my above comment about orthogonality. Writing >> a superposition as a sum of possible eigenstates does not necessarily imply >> interference, not if the states are orthogonal, which is usually assumed. >> AG* >> >> >>> If it is the position, like in the two slits, interference comes from >>> the existence of state “superposing” two (or more) states from the base. >>> The interference is, somehow, the superposition itself, when recombined at >>> some place (screen, interferometer, etc.) >>> >> >> *In the double slit, there IS interference between the waves exiting from >> each slit. But IMO this should not be generalized for all superpositions of >> quantum systems. As I wrote, I believe that from this seminal experiment, >> arose the general interpretation of superposition, which I contest. So far, >> I have not seen any justification of this extension. It leads to the false >> belief IMO, that systems in superpositions are simultaneously in all >> component states, from which we the MWI and cats alive and dead >> simultaneously. In the latter case, Brent claimed that Schroedinger got it >> wrong, and that decoherence theory explains it by asserting the cat is in >> the apparently contradictory state for only fractions of nano seconds, so >> we never see that state.* >> > > > > > > *The comment below in RED is incorrect. Although the apparatus A(or > device) has decohered way prior to being part of any experiment, the wf > given earlier by Bruce in the context of decoherence theory is correct > (omitting the normalization factor), namely,|Up> |A+> |E+> + |Dn> |A-> |E-> > where A+ and A- are states of the Apparatus after measuring the particle > spin Up or Dn respectively, and E+ and E- are states of the Environment > after measuring the particle spin Up or Dn respectively. Each component of > the superposition is a possible eigenstate of the *total* system after > measurement. I confused two processes of decoherence; before the experiment > commences for the Apparatus and Environment, and afterward. * > > > OK. Good. > > > > > *Nevertheless, I still stand with Schroedinger that in any quantum > superposition, other than for slit experiments, the system cannot be in all > eigenstates simultaneously before measurement.* > > > Then you can no more explain the working of an interferometer, or > polariser, or even the structure of the hydrogen atoms, molecules, etc. You > are just saying that QM works for the double slit, but not for anything > else. That is contrary to the fact that QM has just never been shown wrong, > at any scale and level. >
*Sorry, but I see you have no clue what I have been claiming in this thread. Although I infer that English isn't your native language, you know it well enough to understand my claim; yet you do NOT. How can you expect to posit new theories about reality, such as based on arithmetic, if you are unable to understand simple English? OK, let me start again. I am NOT questioning the CALCULATED results of QM. All I am asserting is that the INTERPRETATION of a quantum superposition of states is wrong if it claims that a system represented by a superposition of states is SIMULTANEOUSLY in all components of the superposition. I make this claim because bases in Hilbert spaces are NOT unique, and I gave the example of vectors in a plane to show that since the number of bases can be huge in number, sometimes uncountable, it mocks the claim that one particular basis is special. If it isn't special, there is no reason to assume that an expansion of a wf for a system in one basis, implies the system is simultaneously in all components of this particular.superposition. When I formally studied QM at the undergraduate and graduate levels, we solved many of the standard problems such as the H-atom, tunneling, etc., and in no case did the assumption about superposition which I claim is unwarranted and false, enter the analysis. I invite you to explicitly and exactly demonstrate where this erroneous assumption is used in these solutions.Note that when we expand a system in a superposition of eigenstates, it is usually assumed that the component eigenstates are orthogonal. Hence no MUTUAL interference. Where we get interference is between the wf itself, and some particular eigenstate, when we apply the postulate for calculating the probability of the occurrence of the eigenvalue of this eigenstate. As you know, unlike classical E&M, in QM we must calculate the NORM-SQUARED to get the probability, and since these functions are complex, the interference terms necessarily appear in the calculation.As for double slit INTERPRETATION, I didn't claim that QM only works for slit experiments. What I claimed is that for this particular situation, where the incoming particle can be interpreted as a wave which goes through both slits and interferes with itself, the superposition CAN BE INTERPRETED as being in both states of the superposition simultaneously. AG* > * I have asked for arguments to support this apparently superfluous > assumption, but none of the usual suspects have ventured forward. Applying > this assumption we get patent absurdities* > > It shocking perhaps, but not absurd. > *No; in fact absurd -- to think Joe the Plumber can do one trial of a slit experiment and create uncountable copies of himself, replete with his memories! Physics isn't always intuitive as relativity shows, but this is because we don't normally experience speeds near the SOL. But what has occurred is that this insufficiency of human intuition has been inappropriately generalized in such manner as to justify dispensing entirely with common sense. **AG* > *like the MWI, among others.* > > > MWI is just QM taken seriously. > *The MWI follows from the assumption in superposition which I claim is not only extraneous, but false. IIRC, it isn't applied in the H-atom or tunneling phenomena analysis. And where it IS used, we get the absurdities of the power of Joe the Plumber. So if we trash this erroneous assumption, the MWI and cats alive and dead simultaneously go away. AG* > The problem is that nobody find better, and all attempt to get the same > result with one world introduce things which are “more absurd” than many > world, like FTL influence, metaphysical indeterminacy, event without cause, > etc. It is a bit too much to satisfied a willing of being unique. > > * Importantly, I don't have the burden of proof that the assumption is > valid. That's the responsibility of the True Believers. AG* > > How do you explain the difference between a mixture of down and up > particles, and particles in the down + up state? > *If you write down how probabilities are calculated for mixtures, I believe I will be able to explain why we get results that differ from superpositions. I don't think it's a mystery. As for particles in the down + up state, I contend that such states are not physically possible. That's why we don't see them. In general, there can be a difference between what can be described or exist mathematically, and what actually corresponds to a physical state. AG * > > QM is the assumption. Are you arguing that QM is false? > *No. Just that there's an erroneous, unjustified assumption concerning the INTERPRETATION of a superposition which leads to ridiculous results -- as Erwin tried to show. But today, many physicists have fallen in love with the illusion. To quote the Great Trumpist; SAD! AG * > > Bruno > > > >> * IMO, this explanation doesn't work for several reasons, one of which is >> that the wf used in decoherence theory assumes the measuring device is put >> in place before decoherence occurs. But how is this possible with such a >> short decoherence time? Long before the device is attached and the >> experiment is performed, it has interacted with the environment, meaning >> that the wf on which decoherence is based, is impossible to establish. AG * >> >>> >>> Do you know the book by David Albert “Quantum Mechanics and Experience”, >>> it is quite good pedagogically, and he explains well the “problem”. He >>> dmisloh Everett very badly (good for Everett!), and defend Bohm quite >>> unconvincingly (for me at least). But he introduces very well the basic >>> core theory, using only very elementary algebra. >>> >>> 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. >>>>>> To post to this group, send email to everyth...@googlegroups.com. >>>>>> 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-li...@googlegroups.com. >>>>> To post to this group, send email to everyth...@googlegroups.com. >>>>> 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-li...@googlegroups.com. >>> To post to this group, send email to everyth...@googlegroups.com. >>> 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-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. 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