Dear Markus Mueller:

I very much enjoyed your essay. It closely parallels ideas in my essay, in which I distinguish between empirical models and conceptual models. An empirical model, like your description of theory, describes objects of observations and their empirical relationships. A conceptual model, like your structure, describes what the theory is talking about, i.e. it tries to define physical reality.

You note that Special Relativity tells us that we cannot answer whether two events are simultaneous. Is this the end of the story? Or should we, as the Theorem and final paragraph in Section II suggest, take this unanswerable question as a deep insight into the possible existence of distinct differentiations?

Special Relativity assumes that all inertial reference frames are equally valid. This is empirically consistent with SR, but it is an added assumption about the nature of physical reality. It leads to 4D spacetime and no definition of simultaneity. Klingman's essay describes an alternative reality, based on a contrarian assumption that physical reality is contextually defined with respect to a particular inertial reference frame. This structure/conceptual model is also empirically consistent with special relativity, including time dilation, but it describes a 3D space with a single time frame, and it embraces simultaneity.

In my essay, I describe the Copenhagen Interpretation as an empirical model of QM. It is focused on predicting measurement results and explicitly avoids questions of underlying reality. As such it is an undifferentiated theory, in which the question "Is randomness fundamental?" is unanswerable.

I consider more-differentiated structures to describe contrasting conceptual models of quantum reality. One conceptual model (I call HCM) adds an assumption that denies fundamental randomness. This assumption equates the wavefunction with physical reality, and both are fundamentally deterministic. I also describe an alternative model, which I refer to as DDCM. It recognizes that absolute zero can be approached but never attained, and it assumes that physical reality is contextually defined with respect to a positive ambient temperature. It describes physical reality as fundamentally random and irreversible. Both structures are empirically consistent with QM, but they yield contrasting answers to the questions of fundamental randomness and irreversibility. (DDCM also resolves the measurement problem and other conceptual difficulties of QM.)

I suggest that the metaphysics of "things" corresponds to a context-free physical reality. Things have independent existence. The metaphysics of structure, which "manifests itself by, and weaves together, 'real patterns'" corresponds to a contextual physical reality, in which elements of reality are defined by their relationship to their objective physical context. Contextual reality with respect to a positive ambient temperature provides a firm foundation for your final hypothesis of a fundamentally probabilistic quantum reality.

I hope you will take a look at my essay and provide your thoughts.

Sincerely,

Harrison Crecraft

    Dear Markus,

    This is a very insightful and very well written essay you have got there!

    The structural realism you put forward coincidentally resonates with some of my recent readings on Poincaré who was also advocating for a form of structural realism well before quantum mechanics.

    A naive query I would have about an ontology based on structure is that it seems to rely on a form of first order logic where predicates, and the rules they may obey, are what remains when what they can act on is forgotten. But I cannot help wonder how would that work if the predicates themselves are instantiations of models in higher order logics; it would seem to run into a form of infinite recurrence of Russian dolls structures that in some sense never stops; unless we select a given model or order of logic.

    I would be interested to read your thoughts on this :) .

    In case you would be interested I develop a similar view in my submitted essay where, as far as I understand your perspective, we claim that finding meaningful differentiations within a given structure (of observational phenomena for example) is in fact a defining feature of scientific practice https://fqxi.org/community/forum/topic/3477 .

    Best of luck for the contest.

    Fabien

      Hi Markus,

      I enjoyed reading your essay. You present some an interesting an very unique perspective.

      If I understand correctly, you are proposing we focus on the structural patterns between elements of physical theories. That is, the relationships between things in the theory are fundamental, not the things themselves? Is this what you meant by real patterns? It was a little vague.

      If I have understood this correctly, I do believe I could get behind this idea with a bit more convincing. There are considerable overtone in your essays to the structuralist ideas of contemporary philosophy which I have been somewhat sympathetic too. I think it might provide some useful insights for the physical sciences.

      In any case, I will be checking out a few more of your papers on this topic!

      Thanks again,

      Michael

        Dear Harrison (if I may),

        thanks very much for your thoughtful comments!

        I really like your insight that "being undifferentiated" can also mean that something is defined in a contextual way. Your example with reference frames in SR is a very good example.

        I would like to find out more about your view on QM (especially what you mean by DDCM), and will try to have a look at your essay if I manage to find the time.

        Best,

        Markus

        Dear Michael,

        thank you for your comment!

        I agree that the notion of "structure" in my essay is a bit vague. One would have to invest more work to make this mathematically and philosophically sound.

        What I do *not* mean by "structure" is simply the relations between things (in the sense, for example, of Newman's objection). What I rather mean is, basically, whatever we can say about the "real patterns" we encounter.

        Ladyman at al. have clearer definitions of this. They write, for example, that certain patterns behave like "things". But the notions of "things" or "relations" are not taken as primitives to ground the notion of pattern or structure.

        Thanks again for checking out my essay!

        Best,

        Markus

        Dear Fabien,

        thanks so much for taking the time to read my essay, and for your comments!

        It's very interesting to hear that Poincare was already advocating for some form of structural realism. Off the top of your head, do you perhaps know a reference for this? I'd be curious!

        Now, regarding your question on the "Russian dolls structure" in an ontology of structure. First, note that answers to your question -- more generally the question of how to think of an ontology of structure, and how to define it much more carefully than in my essay -- can be found much better in the works of philosophers who have written about this in much more detail. My favorite source is still Ladyman.

        Now, second, I guess that the way I understand "structure" is different from how it is used in your argument. I totally agree that there is this infinite-recurrence problem that you describe -- if one relies on a view in which we have "mathematical objects" (the individuals) and their "relations" (the predicates etc.), and that an "ontology of structure" means to drop the former and keep the latter.

        But this is not how I want to understand "structure". Rather, I'd use "structure" as the whole package of what a given consistent formal system, or theory, talks about. It is what all models of a given theory have in common.

        This is vague for two reasons. First, because for the essay I didn't do the hard work one would have to do to make this philosophically and mathematically more rigorous. Second, I believe that it *must* appear vague to some extent because our intuitively "most concrete" ideas are those of things and their properties, and these notions are exactly what's avoided here to begin with.

        Good luck for the contest to you, too!

        Best,

        Markus

        Hi Markus,

        Congratulations to the well-organized essay. I learned so many quantum foundations topics from this. In your quantum-optimistic hypothesis, how to deal with the data-driven science to be approached to quantum mechanics? On quantum mechanical objects or events, this seems to NOT be reproductive even by the future AI technology if this hypothesis is true.

        Best wishes,

        Yutaka

          Dear Markus,

          Thank you so much for writing this essay. I enjoyed reading it very much, and learned a lot of stuff. I think the message is somewhat orthogonal to my essay, but not necessarily contradictory. I like your viewpoint regarding how we implicitly assume there to be a metaphysics of things, and how this may be mistaken.

          Thanks again, and all the best,

          Gemma

            Dear Markus,

            I really enjoyed reading your essay, and I sympathize with a lot of your ideas.

            Especially, the fact that letting go of the concept of "things" and acknowledging that some questions have no answer, "dissolve" the paradoxes and avoid the invocation of weird ontological phenomena. Indeed, quantum theory invites to consider the notion of "entities" (as they were defined since Aristotle, individual objects with determinable intrinsic properties) as an "epistomological obstacle" as philosopher Gaston Bachelard might say. A metaphysical distancing from the notion of "things". While I was preparing my essay, I came across this quote from Rothstein, which I think might be in line with your "dissolution of questions" : an `` operational meaning can be assigned to question with respect to a system of interest which does not include the observer. Applied to the universe as a whole, these question lose their operational significance and become physically undecidable, they become metaphysical questions.''

            I really enjoyed your defense of an "optimistic" view. It is true that interpretations acknowledging this analysis are very often mistaken with "incomplete" knowledge (epistemic restrictions) about ontic things ; or they are straightforwardly labelled as anti-realistic, without specifying "anti-realistic towards what". Not towards the existence of an external word, but towards the notion of "things".

            I guess there might an ambiguity in your essay (or a misunderstanding from me), because I don't see QBism as "an epistemic restriction" which can be compared with Spekkens's view. I rather see it as something that might get along with your view, an optimistic position based on acknowledging that some "questions don't have answers" not because of a lack of human ability, but based on a fundamental, logical argument.

            Instead of taking a metaphysical stance as you do, arguing for an ontological realism of structures ; I tend to be sceptical towards sentences such as "the world is" (which are often related to a naïve realism (based on "things")). So I am not sure that I completely rely on your view that "the world is about structure". The word "structure" seems quite vague and ambiguous... and I prefer (for now) to strive for an "epistemological modesty" rather than designating what is ontological or not. However, you solution is way more appealing than naïve realism, since it is proposed after a careful analysis about the (un)decidability of questions. So I rather prefer your conclusion : "We can know what there is to know." Which resonate with Bohr-like sentences : "There is no quantum world. Physics is about what we can say about nature".

            If you ever find the time to read my essay, I would be glad to have your feedbacks on it. You go further than my analysis, proposing an ontological path to follow (structuralism) while I stopped at the dissolution step (for now). However, your notion of "Structural differentiation" seems rather close to my concept of "meta-contextuality", and I am very curious to have your thoughts on this.

            I hope that your essay will do great in the contest.

            Best,

            Hippolyte

              Hi Markus,

              your essay is definitely my top pick for this contest, thank you for contributing! You state in your concluding hypothesis:

              "The quantum world is probabilistic structure. In other words, it is not a "thing" or a collection of things, but it is the multitude of statistical patterns and their structural relations that any observer encounters in their data."

              So is the question here then how our discrete observational experience of a 3D world emerges from the probabilistic structure of our observations? 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? A sort of QBist realism meets radical empiricism for which there is only the real patterns of our observational experience?

              I've long been a fan of Dennett's take on phenomenal experience (the manifest image) and its 'real patterns', or the persistent regularities of our sensory perception (cf. Husserl). Our species has evolved to perceive complex patterns in the phenomenal flux of visual, auditory, chemical, and somatic sensory experience, and where those patterns are predictive they can be considered 'real', with the natural (phenomenal) numbers being a case in point. I take it Peano's axioms would then be an account of the modern structural relations evident in the real patterns of our natural/phenomenal counting experiences, along with whatever ontological assumptions that might motivate those axioms? Such as, for some, a rather quaint (and in this case a posteriori) belief in Platonic realism for numbers.

              The ontic/conceptual structure then consists of identifying the dynamic relations between factical/real patterns--with structure defined by ontological and mathematical concepts that can explicate those patterns in terms of formalized predictions--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!

              In this way the structural 'laws of physics' and the ontology that informs them emerge from the real patterns observed in scientific/empirical experience. So your ontic structural realism is then an observer dependent realism? 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? What is real are the patterns (the information) ... where an observer might be defined as nothing more or less than the flux of its observations situated, by simple definition, at the centre of its observable universe of real patterns and their probabilistic structural relations.

              And finally, is it this first person ontology of the observer that might provide a structural differentiation from the early modern (delusional) godlike third person perspective that reduces the observer to a simple automaton located in an unobservable classical container world of the Ding an sich?

              Apologies for crowding your thread but I find these questions fascinating and closely aligned with my own philosophical prejudices!

              All the best,

              Malcolm

              Je suis, nous sommes Wigner!

                Dear Markus,

                Your essay is one of the few that I could identify with. While I am not very sure of how close our views are it seems we agree that reality is computable. My model sort of points outs that nature is a mathematical structure that represents probability structure as in "geometric probability", also taken line-line or circle-line picking as examples. you can see that the expectation value characterizes the "process", I would guess similar to you idea. Moreover, when I interpret the line lengths(after some summing procedure and inverting and normalizing) as energy many results that agree whith QM and QFT is obtained. Also my model sort of agrees generally with

                https://www.physicsforums.com/threads/the-thermal-interpretation-of-quantum-physics.967116/

                I hope you are discouraged by my low score, since I am not into political chit chating just for the score. Thanks

                  I hope you are discouraged by my low score, since I am not into political chit chating just for the score. Thanks

                  of course that shout read

                  I hope you are NOT discouraged by my low score, since I am not into political chit chating just for the score. Thanks

                  Dear Professor Markus

                  I got a very nice introduction to you from Prof. Malcolm Riddoch, this post is about furthering that discussion...

                  This will give me a fundamental approach to the quantum mechanics. I will go thro' your essay soon of them and contact back to you ASAP.

                  I mainly worked in cosmology , I am yet to enter into the world of Quantum Physics, i will do that in discussion with you and your friends...

                  Meanwhile he asked me about my possible fundamental concepts??

                  These are the Fundamental concepts of Dynamic Universe Model taken from my essay, Have a look at my essay for further details....

                  C.1. Logical and Physical foundational points of Dynamic Universe Model:

                  -No Isotropy

                  -No Homogeneity

                  -No Space-time continuum

                  -Non-uniform density of matter, universe is lumpy

                  -No singularities

                  -No collisions between bodies

                  -No blackholes

                  -No warm holes

                  -No Bigbang

                  -No repulsion between distant Galaxies

                  -Non-empty Universe

                  -No imaginary or negative time axis

                  -No imaginary X, Y, Z axes

                  -No differential and Integral Equations mathematically

                  -No General Relativity and Model does not reduce to GR on any condition

                  -No Creation of matter like Bigbang or steady-state models

                  -No many mini Bigbangs

                  -No Missing Mass / Dark matter

                  -No Dark energy

                  -No Bigbang generated CMB detected

                  -No Multi-verses

                  C.2. Main ETHICAL foundational principles of Dynamic Universe Model:

                  -Human Accrued knowledge should be free to all

                  -Concept should come out from the depth of truth;

                  -Authors / Scientists thinking should go towards perfection;

                  -Logic should be simple

                  -Theory's predictions should be verifiable experimentally, by anyone and anywhere with the same conditions

                  -Computations / computer programs should be simple

                  -ontological realism of senses produced information

                  -New theory lead us forward into ever-widening thought and action experiments

                  -Let the new theory lead us into that heaven of freedom.

                  C.3. Main PHYSICAL and COSMOLOGICAL foundational principles of "N-Body problem solution: Dynamic Universe Model":

                  -Natural universe regularly undergoes change in shape due to mutual Dynamical

                  Gravitational forces.

                  -Accelerating Expanding universe with 33% Blue shifted Galaxies

                  -Newton's Gravitation law works everywhere in the same way

                  -All bodies dynamically moving

                  -All bodies move in dynamic Equilibrium

                  -Closed universe model no light or bodies will go away from universe

                  -Single Universe no baby universes

                  -Time is linear as observed on earth, moving forward only

                  -Independent x,y,z coordinate axes and Time axis no interdependencies between axes..

                  -UGF (Universal Gravitational Force) calculated on every point-mass

                  -Tensors (Linear) used for giving UNIQUE solutions for each time step

                  -Uses everyday physics as achievable by engineering

                  -21000 linear equations are used in an Excel sheet

                  -Computerized calculations uses 16 decimal digit accuracy

                  -Data mining and data warehousing techniques are used for data extraction from large amounts of data.

                  Best wishes to your essay

                  =snp

                    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