Dear Mueller:

Excellent scholarly article.

I basically agree with your views:

"I argue to replace this perspective by a worldview in which a structural notion of 'real patterns', not 'things' are regarded as fundamental. Instead of a limitation of what we can know, undecidability and unpredictability then become mere statements of undifferentiation of structure."

..... but only partly, because "undifferentiation of structure" acknowledges our persistence ignorance. In fact, that is point of my essay.

Please, make time to read my essay and grade it.

"Complete Information Retrieval: A Fundamental Challenge"

https://fqxi.org/community/forum/topic/3565

The universe is fundamentally stochastic because the observable radiations and particles are emergent oscillations/vibrations of the universal cosmic space, which is, at the same time, full of random "background" fluctuations. These fluctuations, however weak they may be, nonetheless are perturbing any and all other interactions going on in the universe. Since, human initiated measurements are also interactions between our chosen interactants in our apparatus, stochastical changes will be inevitable in every measurements, classical or quantum.

I am an experimentalist. Aprreciating persistent & continued incompleteness in our knowledge does not require complex philosophical arguments. Our measurements will always be imprecise. That we had been, we now are, and we will always be, information limited, emerges naturally when we enumerate the basic steps in any measurement:

(i) Data are some physical transformation taking place inside the apparatus.

(ii) The physical transformation in a detectable material always require some energy exchange between the interactants, the "unknown" and the "known", where the "known" is the reference interactant.

(iii) The energy exchange must be guided by some force of interaction operating between the chosen interactants.

(iv) Since we have started with an unknown universe, from the standpoint of building physics theories, the "known" entities are known only partially, never completely. This also creates information bottleneck for the "unknown" entity. Note that in spite of innumerable experiments, we still do not know what electrons and photons really are.

(v) All forces of interactions are distance dependent. Hence, the interactants must be placed within the range of each other's mutual influence (force-field). Force-field creates the necessary physical "entanglement" between interacting entities for the energy transfer to proceed. In other words, interactants must be "locally or regional" within their physical sphere of influence. They must be "entangled" by a perceptible physical force. Our equations are built on such hard causality.

(vi) The final data in all instruments suffer from the lack of 100% fidelity. This is another permanent problem of imprecision. We can keep on reducing the error margin as our technology enhances; but we do not know how to completely eliminate this error.

Many of my earlier papers have also articulated this position. They can be downloaded from:

http://www.natureoflight.org/CP/

You can also download the paper: "Next Frontier in Physics--Space as a Complex Tension Field"; Journal of Modern Physics, 2012, 3, 1357-1368 , http://dx.doi.org/10.4236/However, mp.2012.310173

Sincerely,

Chandra.

Prof. ChandraSekhar Roychoudhuri

    Hi Markus.

    Poincare's stucturalism is found in his Science ad Hypothesis. There was a whole bunch of other related stucturalisms too, of Russell, Eddington and others, aiming to get an isomorphism between our experience of the world and the world itself. Things beyond the structure had to go, at least from the point of view of science's scope. My essay is slightly similar to yours in that it ultimately ends up pushing towards some kind of structuralism (though I don't quite call it that).

    But, given the every thing must go approach, there is a potential problem with structural underdetermination that various dualities seem to pose: these are structurally different, yet would generate what seem to be the same phenomena [e.g. AdS/CFT]. This would pose problems for your view since we then face the same question as for things: which structure is being observed? How might you deal wth this, assuming it's valid?

    (My essay is here: https://fqxi.org/community/forum/topic/3450)

    Best

    Dean

    Dear Marcus Mueller,

    Essays on top of community ranking tend to not even notice those who are ready to fundamentally justify the wave function and the redundant FT as a fundamental of it.

    I nonetheless very much enjoyed reading your anti-agnostic worldview which I share in principle. I thank you very much for reminding of Euclidean geometry which I understand as a special case of the elliptical one. Isn't use of mathematics often too less or inappropriately differentiated? To me the denial of distinction between past and future implies an unjustified arbitrary choice of the reference point which may cause confusion.

    I would like to see you on top of ranking and also on job even in case Kadin will not be quite wrong.

    Eckard Blumschein, an old Berliner

      Dear Markus Mueller,

      Your essay is extremely well written with sharply presented arguments. One can agree that the world which is open for opportunities (unpredictable) provides generally optimistic perspective though sometimes reality bites painfully as one can see. Questions which remain are of deeper foundational nature: why it is as it is, e.g. your hypothesis about the quantum world. It has to be originating from an underlying structure unless one accepts that every possible world exists and we just happened in this one.

        This is a thoroughly brilliant essay. It offers, if not optimism, a palliative to even the most realistic of scientists.

        In my essay I offer a perspective that is even more optimistic: The world is inherently spontaneous (not random and not determined), which is why we observers are inherently spontaneous, and that is why knowledge can only be tentative and limited. The world is not strange, but rather, like us, it is wonderful.

          Dear Professor Mueller,

          It was a pleasure reading your beautiful essay, whose overall philosophy I agree with. I fully support redefining and reinterpreting realism to make it in accord with what physical theories present us.

          With regard to quantum mechanics, my view is that the unpredictability and indeterminism are not fundamental. Rather they emerge as apparent effects when an underlying deterministic theory is coarse-grained. I explain this in my new arXiv preprint

          Nature does not play dice on the Planck scale

          and also in my essay in this contest. Hope these will be of interest to you.

          My thanks and best wishes for your success in this contest.

          Tejinder

            Hi Dean,

            ah, excellent, thank you for the reference! I'll have a look at it, and will also see what Russell and Eddington had to say.

            And thank you for your thoughtful comment on structural underdetermination! I would say that this all depends on what we exactly mean by "structure" -- a question that I haven't tried to answer in detail in my essay (I've kept it somewhat vague). In AdS/CFT, for example, depending on the answer to this question, one could either say that the boundary CFT and the bulk gravity theory are different structures, or that they are the same. It depends on what kind of notion of "equivalence" of structures we accept.

            However, I think here we are in a better position than in the context of "things": while a "thing" is usually imagined as a kind of god-given entity with clear boundaries, we have quite a few different options to clarify what we mean by "a given structure". Hence I'm optimistic that the question of "which structure" (that you posed) could be clarified. But more work would be needed (and has probably been done by the philosophers).

            Best,

            Markus

            Hi Yutaka,

            good to hear from you, and thank you for your comment!

            I would say that the fact that a given event cannot be predicted even by future AI (if I understand your suggestion correctly) is a good thing -- at least if you want to rely on quantum cryptography, for example. :-)

            Of course, this doesn't mean that data-driven science or computation cannot tell us anything new about quantum mechanics. Even learning the quantum-mechanical properties of large systems seems to be something where such science, and perhaps AI, can be immensely useful

            All the best,

            Markus

            Dear Gemma,

            thanks so much for your kind words! I'm glad you enjoyed the essay.

            I believe that our views are not really orthogonal, they are just emphasizing different aspects. I fully agree that "undecidability is everywhere". Whether we see this as a limitation (for example, we cannot predict all aspects of some system) or as a positive outlook (differentiation is everywhere) may be a matter of perspective.

            Hope to discuss this in person once the crisis is over!

            Best,

            Markus

            Dear Hippolyte,

            thanks so much for your kind words, and for your detailed comments!

            I agree that there is a big difference between Spekkens' view and QBism. Seeing the quantum state as some kind of incomplete knowledge is very different from seeing it as an agent's belief, and there are many more differences between these views. Still, I think that they have something in common: they see the quantum state as something that pertains to some notion of observer which is seen as holding incomplete information in some sense. Hence, both views express the hope that more can be said about the part that is not known to the agent that assigns the quantum state, presumably about some underlying reality: either by finding a kind of plausible "causal" ontological model, or by understanding what the Born rule has to say about the world on which we place bets.

            I also agree that the word "structure" is ambiguous. I guess there are two reasons for it: first, this is only an essay, and I didn't do the hard work to make this notion mathematically or philosophically sound or fully concrete (the structural realists among the philosophers have more to say about this). Second, however, it must *seem* vague to some extent: after all, what we would intuitively label as our most "concrete" understanding is naturally in terms of *things* -- and this is a view that is explicitly rejected here.

            I will try to have a closer look at your essay, the abstract sounds very interesting!

            Best,

            Markus

            Dear Malcolm,

            thanks a lot for the thoughtful and fun comments! I'm glad you liked my essay.

            You write: "And for you might this ontic structural - quantum - realism also be a form of wave function realism where the quantum side of that realism equates to a pure potentiality for experience rather than a thing-like external quantum world?" Yes in fact! I'm stunned that you managed to formulate what I mean so clearly, even clearer than I did myself in the essay!

            Regarding Dennett's real patterns, I'm a big fan of this (and referencing it myself), but I think there is a hidden subtlety that is related to other issues like Goodman's New Riddle of Induction. To say what a pattern is, you have to choose a compression algorithm, or a universal machine (which is analogous to a choice of language). For finite data, the notion of compressibility will depend on this choice. Any ultimate definition of a real pattern will have to deal with this issue in some sense...

            I really like this paragraph of yours:

            "... and the history of science becomes the history of technological advances in our real pattern finding (from Kepler's telescope to the Michelson-Morley experiment and on to Aspects' entangled photons) leading to whatever necessary paradigmatic updates might be needed on the structural relations side with their subsequent technological innovations and so on... Which brings us to the contemporary conceptual mess of 21st C quantum foundations!"

            :-)

            Very well described!

            Just a final comment on this question of yours:

            "I assume this is where your 'law without law' research project begins, with a first person perspective using algorithmic probability to assign structure to sense data patterns?"

            Even though algorithmic probability is used in this approach, the idea is somewhat different. In some sense, it starts with a form of methodological solipsism: there is your state S now (intuitively, containing your sense data and memory), and you will be in another state T next. In that approach, what that next state will be doesn't depend an any "external world" (as we would usually think), but only on algorithmic probability P(T | S). Why such an approach? Well, suppose we are interested in "observer paradoxes" like Parfit's teletransportation paradox (or others, e.g. simulating observers on a computer), and we claim that there is an objective chance of what such an observer will see in those situations. Then the answer, almost by definition, cannot be grounded on properties of the external world (even if there is one).

            Surprisingly, one can show that, if we assume such law, then things look in the long run, for any observer, pretty much *as if there was* an external world. So the notion of "world" is emergent there, and an abstract notion of "self" is fundamental.

            In case you're really interested, there's a link to an online talk on my homepage (mpmueller.net). But enough of advertisement.

            I'll try to have a look at your essay. I'm curious now!

            Thanks again, and all the best,

            Markus

            Dear Chandra,

            thank you for your comments!

            Let me ask a clarification question. When you point out that we are "information limited", are you then saying that this will forever prevent us from getting any "final answers" about reality? In the abstract of your essay, you seem to argue the other way: that we can make progress nonetheless.

            You also write: "Unlike Copenhagen Interpretation, we do not need to give up visualizing ontological reality." So are you claiming that there is an underlying reality in the usual hidden-variable sense, and that we can get our hands on it?

            Best regards,

            Markus

            Dear Eckard Blumschein,

            thank you for your comment! Honestly, I don't quite know what to make of it... but I thought I'd send you best wishes to Berlin, where I've lived for several years.

            Best,

            Markus

            Dear Irek Defee,

            thanks very much for your kind words!

            I fully agree: it makes sense to have a generally optimistic perspective, but sometimes reality bites painfully.

            About the quantum world: yes, many different views are possible, and I'm not claiming the final word on this. The questions of "why these laws of nature and not other ones" and "how to think about all possible universes" are deep, hard and far-reaching, and I'm not trying to say anything about this in my essay.

            Best,

            Markus

            Dear James Arnold,

            thanks very much, I'm glad you liked my essay!

            I have some sympathy for your view of quantum events as spontaneous -- it paints a quite vivid picture, and points out that it is not just about "uncontrollable external perturbations". But can your view also be coined in the more familiar terms of "intrinsic randomness"?

            Best,

            Markus

            Dear Tejinder,

            thanks a lot for your kind words!

            Let me ask you a question on your approach. If dynamics at the Planck scale is fully deterministic, and coarse-graining leads to quantum mechanics, then Bell's theorem implies that this dynamics must be non-local (as you also point out in your paper). But if it's non-local, an immediate worry would be that it leads to superluminal signalling. Is it clear that the coarse-graining in your model removes the possibility of signalling?

            Best,

            Markus

            Thank you Marcus, for asking an important and interesting question. I try to explain what I mean by non-locality in this matrix dynamics, and why it does not imply superluminal signalling. In this dynamics at the Planck scale, there is no space-time. There is only a new notion of time - the Connes time. All processes take place in a Hilbert space, where there is no conventional notion of distance [space-time emerges subsequently, from this Hilbert space, after spontaneous localisation]. So, whereas Alice and Bob are two space-like separated observers from the viewpoint of a conventional Minkowski spacetime, who are making their respective measurements, the picture of the same set-up is very different in matrix dynamics. From the viewpont of this new dynamics, a correlated pair of say electron and positron in an entangled state are represented by operators evolving with time, but this evolution does not imply that the electron and positron are moving away from each other. We must not think of them as spatially separated. Also, one talks of simultaneity in Connes time, which plays the role of an absolute [reversible] time. When Alice makes a measurement on the electron, it simultaneously changes the state of the positron [simultaneous in Connes time]. But no travel or signalling is involved.

            I explain this in some detail in this paper:

            https://arxiv.org/abs/1903.05402

            starting at the bottom of p. 26. Basically, there are two different ways of lookimg at an EPR event. One is the space-time-less matrix dynamics way [non-local but no signalling], and the conventional way..involves signalling. Quantum non-locality appears to violate relativity if we accept that QM needs space-time. But qm does not need spacetime - in fact spacetime is external to qm and must be removed so as to find a better description of qm. The matrix dynamics achieves that - because there is an absolute time, but no light-cones. Lorentz invariance is emergent.

            I will be very happy to discuss this point further with you. Do let me know what you think.

            Thanks,

            Tejinder

            I really enjoyed this essay. Relating the incompleteness theorem to Euclid's axiom is a great illustration of the point which really puts the issue of incompleteness in a new perspective. And I agree that much of our trouble with the interpretation of quantum mechanics comes from asking the wrong questions and attempting to force the theory into an over-specific ontological structure.

            I wondered about your phrasing of the 'unanswerable questions' in quantum mechanics - 'What is, at some given moment, the actual configuration of the world?' Relativistically the concept of 'the state of the world at some given moment' isn't well-defined, so it would seem that it follows directly from relativity that this question is unanswerable, and therefore quantum mechanics wouldn't be adding anything very new here. Or did you mean 'at some given moment' to refer to 'on some spacelike hyperplane of simultaneity'?

            I also think there's an important difference between the case of quantum mechanics and the case of 'the same time.' In the case of relativity, Einstein did not simply assert that it so happens that questions about 'the same time' have no answer - he argued convincingly that these questions are meaningless (in our universe and in a large class of universes like ours). Whereas quantum mechanics doesn't seem to show us that 'What is the actual configuration of the world (on some suitable spacelike hyperplane)'? isn't a well-posed question - rather it's just a contingent fact that in our actual world this question has no answer (if it is indeed a fact!). So the claim that this question is unanswerable seems less logically compelling then the claim that 'same time' questions are unanswerable (though of course that doesn't mean it isn't true!). I wondered if you agree, or if you think there's a stronger claim to be made to the effect that questions about the actual configuration of the world aren't even meaningful?

              Dear Professor Markus

              Hope you will have a visit to my essay, before time expires

              Best

              =snp

              The idea of actual, physical randomness is an odd one. If it isn't meant to be due to a complex of unrelated extrinsic causes, to be extrinsically uncaused, and intrinsically foundationless, would be the best explanation for nothing happening at all.