Hi Cristi,

Nice essay, easy enough to read that even I can understand it (I am not a physicist).

I agree with your global consistency principle, I have an example of how it could be implemented.

In my essay (Definetely It from Bit !) the Universe is a succession of 2D layers of information (like rings around an onion). We (and our surrounding world) are just information moving up the layers at the speed of light. In relation to each layer, the inner layers represent the past and the outer layers represent the future. Each layer can evolve separately but they must always form a "coherent" storyline. (there are as many "presents" as there are layers).

If I am correct, then the consecutive layers (ie: the complete information sphere) could be what you call "the solution (it) which combines consistently all the pieces of the puzzle (the yes/no bits at different points and moments of time)"

Cheers,

Patrick

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    • Post #48

    Cristinel,

    Could you please comment on [/link:http://arxiv.org/pdf/1007.3977v1.pdf] B Gaasbeek (2010) [/link] Demystifying the Delayed Choice Experiments, arXiv:1007.3977v1 [quant-ph] 22 Jul 2010

    Your delayed initial conditions are intriguing to me who did not yet deal with that matter. Did you get support?

    Best regards,

    Eckard

    Cristi,

    I must take exception to your statement that "The main mystery of quantum mechanics is contained in Wheeler's delayed choice experiment."

    Last September, in the discussion of my essay for the previous FQXI essay contest, I pointed out that the delayed choice experiment, was not merely badly designed, but badly conceived. The telescopes block the path from a slit just as surely as if the slit had been closed. It thereby precludes any possibility for this apparatus to produce an "interference pattern".

    It is not the case that "the past is determined by our choice", rather it is "the path is determined by our choice".

    Consequently, Wheeler threw the baby out with the bath water.

    Rob McEachern

      Hi Patrick,

      Interesting the onion layers idea. I look forward into reading your essay.

      Thank you for the feedback. I made extra effort to reach a broader audience.

      Best regards,

      Cristi

      Robert,

      The path decribes a history, does it not?

      Tom

      Dear Robert,

      I think you have a keen eye for telescopes and optics. Delayed choice experiments, not at galactic scale, but at lab scale, were performed, and the delay was ensured. The experiment confirmed the theoretical prediction.

      Wheeler proposes the delayed choice experiment with the Mach-Zehnder interferometer, and also the one with a telescope and galaxy. I think that the one with telescope and galaxy is an exaggeration, done for explanatory reason. Something like Brian Greene's Quantum Cafe, or Gamow's books with Mr. Tompkins, where quantum or relativistic phenomena are "zoomed" at a level which makes them relevant to our daily experience. Or like Bohr's quantum devices, with exaggerated mechanical parts.

      I am not sure that Wheeler really tried to design a workable experiment involving telescope and light from other galaxies. One big issue I think it is the lack of control of the source of light. By looking at Wheeler's drawing of the experimental setup, in Quantum Theory and Measurement, p. 139, we see that the device is more like Bohr's drawings of devices. But even so, I don't see in that picture how the telescope would block the path from a slit. Perhaps you analyzed a different picture than the one I found.

      Thanks for the comment, and keep questioning everything! When we stop questioning, science stops.

      Cristi

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      • Post #53

      Dear Eckard,

      Thank you for the link to the paper, I don't remember knowing it. A short glance makes me add it on my to do list of readings. I hope I will come back soon with comments, but if you have a specific point which you have in mind, please let me know. Regarding delayed initial conditions, I think the idea is supported by quantum phenomena, but then, what interpretation of QM is not? Or, if by "did you get support", you refer to funds, I don't have.

      Best regards,

      Cristi

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      • Post #56

      Cristi

      My comment about is has happened was in the context of observation. In general, mu comment about happened is that something definitive occurred, existence does not do vagueness. So the point is thatobservation can have no effect on the physical circumstance, and if we cannot discern what actually happened then that is our failure, not some inherent characteristic of physical existence.

      Paul

      Christi,

      The statement "The experiment confirmed the theoretical prediction." is incorrect.

      The experiment confirmed that the interference pattern vanishes. But it failed to confirm that the cause for the vanishing is due to the cause that was predicted. It was not.

      The situation is analogous to preventing two cars from interfering (colliding) with each other at an intersection. Delaying one car will prevent the collision, but so will completely eliminating one car.

      In effect, the experiment simply eliminates one travel path, via a spatial filter. The delayed choice is irrelevant - if there is no path, there can never be any interference, regardless of any delayed choice.

      The telescope I was referring to is not an astronomical one. It is part of the laboratory interferometer, and used to "choose" the slit.

      Rob McEachern

      Robert,

      Thank you for the clarifications. In fig. 2 and 3 in my essay I draw the two situations of the delayed choice experiment with the Mach-Zehnder interferometer. I don't see the detectors (are they the telescopes?) change, yet the result changes, depending on whether the second beam splitter is present or not. I don't understand your argument how it is the detector the one that makes the difference. Maybe, if you have some drawings, will help.

      Best regards,

      Cristi

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      • Post #59

      Dear Cristi,

      While I consider myself unbiased, I enjoy common sense arguments like your delayed initial condition, Rob's car accident comparison, and Paul's independence of reality from observation. Of course, as an EE, I am familiar with the impossibility to measure something without disturbing it, for instance because there is no voltmeter with infinite resistance. The disturbed reality is not the reality one intends to observe.

      When I asked you whether your idea has already been supported, I meant ideal support by other experts. I guess that it may be understood as undermining Wheeler's intention to justify his absorber theory, travel backward in time, and it from bit. Perhaps, many honest experts will be cautious, and I doubt that there will again be almost 300 contributions to the contest this time, although in particular the many experts of computer science are now addressed.

      Best regards,

      Eckard

      Paul,

      If by "happened" we understand what was observe, what has observable consequences, then we agree 100% that what "what happened has already happened". The only difference may be in the order of the events. In classical mechanics, time is linear, in quantum mechanics, in some cases, is not, as I will explain. Time is a parameter, very similar to how space coordinates are. In classical mechanics, the events happen as time goes. In other words, all the events labeled with time smaller than t already happened at time t. Time is linear. In quantum mechanics, the things are really different, in the sense that the order in which the events happen may be different for that of time labels. In the case of the Mach-Zehnder interferometer, the photon leaves the first beam splitter, and arrives at the place where the second beam splitter may or may not be. The interaction between the photon and the second beam splitter takes place or not (if the beam splitter is not there). This is the happening at the second beam splitter. Then, and only then, the happening at the first beam splitter takes place. The happening at the first beam splitter, so to speak, stays suspended, until the happening at the second beam splitter gives enough information to the system, so that the photon will know whether to go one way or both ways. So, I agree that "what happened has already happened", except that, for quantum phenomena like the one discussed, the order is not the linear order of events. If we want, we can say that the order is linear, and the happening at the first beam splitter took place before the happening at the second one, if we assume that the photon can guess the future. Even in this case, the causal order is reversed, because the photon's "choice" is decided by a future event which it guessed.

      Best regards,

      Cristi

      Dear Eckard,

      The "delayed initial conditions" view is a way to see things in quantum mechanics, so that they make more sense to me. I more or less agree with most interpretations of QM, each of them explains phenomena in a way or another, so that they make more sense to one group or another. But each one of them, including mine, had to start from a point which contradicts common sense. I like mine, because I consider it natural, in the sense that it doesn't add extra things to the wavefunction, it only considers that initial conditions are not 100% chosen, and much remains to be chosen in time. In fact, we can say they are chosen, if the choice takes into account what may happen, hence global consistency condition. I received positive feedback from a very small number of experts in the field, but my views are far from being even considered equal competitors with other interpretations. One thing I like at this view, is that it is best understood when considering global consistency, and this makes the things more compatible to relativity, unlike other interpretations, which seem to violate it. Moreover, it makes the block view more flexible, in the sense that the solution is not determined completely at t0. This is close to the evolving block universe of Ellis, except that for him the past is fixed, and choice resides in discontinuous collapse.

      Best regards,

      Cristi

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      • Post #62

      Eckard

      "Of course, as an EE, I am familiar with the impossibility to measure something without disturbing it"

      There are two aspects to that statement:

      -the practical which you allude to, ie the degree to which measuring accurately and comprehensively captures what actually occurred

      -the more fundamental point that measuring/observing/etc, cannot affect what occurred, because it has already occurred. And, whilst that is sufficient to dispense with this false notion that observation/consciousness/etc has a physical role, suffice it to say that the interaction involves a physically existent representation of what occurred anyway, and not the occurrence itself, which is usually light.

      Paul

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      • Post #63

      Cristi

      "If by "happened" we understand..."

      Well it is not possible to observe something which has not happened. And my concept of observe includes valid hypothesis, ie virtual sensing. That is, what demonstrably could have been observed had it been possible to do so.

      The concept of time revolves around the rate at which alteration occurs. That is, there is no time (because there is no alteration) within a reality. Time relates to a feature of the difference between realities, ie speed of 'turnover'. Timing being the measuring system whereby we calibrate it by comparing different rates and identifying the difference. Events can only occur in a sequence. And presuming that something very bizarre does not happen to light in its travels, then we will receive a light based representation of the sequence in the right order. The frequency is more likely to be affected. Existence can only occur this way, which again points to the fact that whilst 'classical' is not understood properly, QM is based on a flawed premise. Nothing can occur 'out of sequence', it is impossible. Neither can something be in different spatial locations at the same time, or in different states at the same time. They must be different. The problem is with our inability to observe/discern what is actually happening at the existential level. Reality does not guess or choose anything. We are the problem, and people should stop adjusting reality to overcome it.

      "But each one of them, including mine, had to start from a point which contradicts common sense"

      And there is the alarm bell for the fact that the theory is wrong. What is, physically, a wavefunction, it is certainly more than one physically existent state.

      Paul

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      • Post #64

      Rob

      Re cars: exactly. There is an understandable human view that the future can be affected. But there is no existent future to be so affected. What is actually happening is that the outcome is different from what otherwise would have occurred, because the causes were different from what otherwise might have prevailed. Which is really a meaningless statement in so far as, by definition, any outcome is the result of preceding causes, but it is imperative to dispense with this notion that physics can occur out of sequence.

      Paul

      Paul,

      What happens with the photon, after it leaves the first beam splitter?

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      • Post #66

      Cristi

      The answer to your specific question is I do not know. But the point is that something happens, ie it is knowable if we had the wherewithall to discern it. Put the other way around, nothing happens which is contrary to how existence occurs, ie there is no pre-existent future, neither does observation cause a particular existence from a range of options, etc, etc.

      Paul