Dear Jonathan,

I want to thank you for reading and commenting my essay. Indeed, too often some ideas propagate in a distorted or misunderstood form, and few have time to go to the source and check with careful consideration. I guess the problem is that there are so many interesting things to do and read in life. This competition is a good opportunity to go back and (re)read some of Wheeler's works. I am glad if I could shed a little more light on the subject. I am looking forward for your essay.

Best regards,

Cristi Stoica

Dear Anton,

I appreciate you posted here such interesting comments, which present a critical view on causality. I think causality has its roots more in our daily experience, and in classical mechanics. This is so rooted in our minds. Theory of relativity and quantum mechanics, were so difficult to understand, hence were initially resisted, mostly because of our preconceptions about causality. Wheeler's delayed choice experiment was intended to show that causality is not what it used to be, so to speak. This doesn't mean that delayed choice experiment shows or claims to show that we can change the past, this occurs only because we assume that the past was in a state, which was then modified, as in the grandfather paradox. "No phenomenon is a phenomenon until it is an observed phenomenon."

Evolution equations are local, and the solutions exhibit local causality, which seems to be violated by quantum mechanics. I proposed that the "global consistency principle" explains this, by constraining local causality so that, globally, there is no conflict. So, global consistency comes first, and local causality later. Local causality is just an illusion of an observer who perceives time as flowing. In the block universe, in which time is just the fourth dimension, as in relativity, global consistency is natural, and local causality emerges only when you go to a dynamical description, in terms of a flowing time. When you tell a 4d story, things look natural, but when you tell it as a 3d story evolving in time, causality becomes manifest, and then appears to be broken by quantum nonlocality and delayed chocie experiments, and we conclude that there are paradoxes. But this is an illusion.

Best regards,

Cristi

I'll summarize here.

There are several points of strong agreement between your essay and my own (yet to be posted), which figure into my current line of research. To enumerate...

There is an interplay between 'it from bit' and 'bit from it' roles at work.

There is a realistic middle ground which global consistency assures.

The deep structure of Math is unavoidably influential on natural law in Physics.

Of course; the second point may be true largely because regularities in Math existing outside our spacetime conceptions rule when there is nobody looking, nor any form to influence. What seems not to be grasped is that rather than imposing a strait jacket which dictates a single outcome deterministically, the deep structure of Mathematics assures that there will be sufficient degrees of freedom for realistic outcomes to emerge.

Recent forays have examined projective geometry as the determiner of object/observer relations, and of course this ultimately leads to an explicit connection with the octonions. Does Math like that predate our discovery thereof? I think it's reasonable to assert that; in some way, all realistic possibilities arise from the deep inner structure of Math.

Regards,

Jonathan

    Already something more..

    Not feeling like I said enough, I'll mention that part of what disagrees with me - about the common conception of 'It from Bit' - is the sense that either/or choices are enough to determine anything. Wheeler was pretty crafty, with his variation on the 20 questions theme, and it's interesting to see how this introduces a kind of telescoping element that later gets reduced down, but allows a flexibility of interim definitions. This allows the process of determination to be playful. I really like that aspect of the story.

    But this description allowing ranges rather than values is fundamentally different from what's normally employed, and is instead more constructivist, heuristic, or lateral thinking oriented. The idea of considering all possible trajectories from A to B requires a non-verbal approach and encourages one to suspend beliefs, in favor of ideas. Something to ponder.

    Have Fun,

    Jonathan

    Dear Cristinel Stoica

    You did a great job, I found your essay very enlightening and well structured. I agree in many points with you. What I could notice is that you open several topics and I'm afraid they cannot be addressed in a small essay. In particular, what drew my attention was your discussion of the mathematical universe due to Tegmark since I have also discussed a bit about it in my essay. I do agree that maths are logical relations and that finding the right mathematical structures that describe the observed data is relevant to quantify and model nature, however, what "worries" me is that from mathematical structures one cannot extract intuitive and tangible explanations of the phenomenology. This is the problem that we have, for instance, with quantum mechanics. The theory has been written in a mathematical language such that most people are uncertain about whether the theory is telling something about reality or it's just a prediction machine.

    From my view, the formulation of physical theories in terms of pure math (without baggage as Tegmark put it) can only give mathematical (or logical) "explanations" of the world but not descriptions of physical phenomena in the intuitive language that we all humans understand. This is in part what I discuss in my essay. I hope you have the opportunity to read it and leave some comments, I'd appreciate it.

    Best regards

    Israel

      Dear Jonathan,

      I enjoyed reading your latest comments too, and it seems to agree at many points indeed. You made some deep remarks, and emphasize correctly the role of Math and lateral thinking. I look forward to reading your forthcoming essay.

      Best regards,

      Cristi

      Dear Israel,

      I appreciate you reading and commenting my essay. I am happy about our points of agreements.

      "what "worries" me is that from mathematical structures one cannot extract intuitive and tangible explanations of the phenomenology. This is the problem that we have, for instance, with quantum mechanics."

      I agree with you that quantum mechanics should be supplemented with something. Its formalism ignores anything except outcomes of quantum measurements. But the world in which we live is also general relativistic, there is also gravity. Having a deeper understand of QM (and GR for that matter) would be helpful in trying to unify them. But ignoring anything but outcomes, by applying "shut up and calculate", would not allow us to go beyond these problems. Those saying that we should "shut up and calculate", claim indeed that QM is complete, because mathematics works and makes the predictions. But if we want to supplement this description, it doesn't mean that what we add cannot be mathematical. In fact, all attempts to extend quantum mechanics or to add content to it are based on mathematics (think at GRW, de Broglie-Bohm, TSV, trace dynamics, etc). The fact that the mathematical description of a phenomenon at a moment of time is not enough, it is not necessarily due to the limitations of mathematics, but of our understanding.

      "the formulation of physical theories in terms of pure math (without baggage as Tegmark put it) can only give mathematical (or logical) "explanations" of the world but not descriptions of physical phenomena in the intuitive language that we all humans understand."

      I am not sure I understand why would be like this. For instance, 1/2 spin, which is elementary and simple, as compared to other things in physics, is well described mathematically, but how to explain it to the "lay man"? One way is to explain the math, this will take time and patience from both sides, but it has chances to succeed. The way without math, no matter how many years will take, will not lead to any progress at all in explaining such a simple thing as spin.

      To put it as a joke, I am not sure why God would have choosen physical laws with the purpose that they can be explained in plain language to the lay men.

      On the other hand, I think that human brained is a tool for understanding mathematics. Maybe the need for survival made our ancestors search for patterns, make abstractions, make deductions. Anyway, no matter what the reason is, people can learn math. I dare to say that most of us can do this, although for some takes longer, mostly because of our resistance to abstract logical thinking which seems to be disconnected from reality. There is also another reason: after WW2, either math became too much and had to be made more concentrated, or the mathematicians became snobs, anyway, they banished the good old geometric interpretations from mathematics, by calling such approaches "too elementary". Vladimir Arnold, in The antiscientifical revolution and mathematics, attributes this to the Bourbaki school, and he may be right. I think that in learning math, one should keep anything that can help, but after that, get over it in our thinking. For example, humans use fingers when they first learn to count and make simple arithmetic operations, but later they no longer refer to fingers in doing this. Such references would slow down thinking.

      So I agree that one should supplement math with something, when we are trying to explain to the laymen. Many scientists try to make their work more accessible by doing this in popular writings, but since science is very active and new things happen all the time, it is difficult to do this with any new idea.

      Thank you for your insightful and stimulating observations. I look forward to read your essay.

      Best regards,

      Cristi

      Dear Cristinel

      I'm also glad that we have some opinions in common. I'd like make some comments on your previous reply.

      You: Having a deeper understand of QM (and GR for that matter) would be helpful in trying to unify them. But ignoring anything but outcomes, by applying "shut up and calculate", would not allow us to go beyond these problems. Those saying that we should "shut up and calculate", claim indeed that QM is complete, because mathematics works and makes the predictions.

      Indeed, shut up and calculate implies that you know what you're calculating, but when there is no picture of what would be the calculation about, this approach looks to me as throwing rocks to nowhere expecting one day to hit the target.

      You: I am not sure I understand why would be like this. For instance, 1/2 spin, which is elementary and simple, as compared to other things in physics, is well described mathematically, but how to explain it to the "lay man"?

      I'm working on this part, we just have to reformulate the notion of particles, this will eradicate the wave-particle duality and the mysteries of QM will fade away. After the make up, QM will look like classical mechanics, highly intuitive.

      You: On the other hand, I think that human brained is a tool for understanding mathematics. Maybe the need for survival made our ancestors search for patterns, make abstractions, make deductions.

      Yeah, but according to some studies, there is one hemisphere dedicated to logical operations and another for intuitive ones. So, the whole brain doesn't work with pure logic, intuition, inference, analysis, irrationality, etc, are processes that play a fundamental role in the generation of knowledge.

      You: I think that in learning math, one should keep anything that can help, but after that, get over it in our thinking.

      I agree, sometimes it is necessary to renew our thinking and get rid of everything that is useless. I'll take a look at the paper you cite.

      Thanks for your comments on my essay, they were very stimulating.

      Best Regards

      Israel

      Dear Israel,

      It seems we agree at all points you discussed. Yet, at one of them, I feel the need to reply. I said "I think that human brained is a tool for understanding mathematics", and you replied with "Yeah, but according to some studies, there is one hemisphere dedicated to logical operations and another for intuitive ones.". I don't see any disagreement here, since I did not say that the brain is exclusively for doing math (anyway, the brain lateralization is also between math: right hemisphere is not only dealing with intuition, but also geometry). I just meant that and it is not obligatory to translate math into another language for people, since their brain is capable of understanding it. I think geometry is the intuitive part of mathematics, so left-right brain means, from math viewpoint, algebra-geometry. I don't recall of any study showing that mathematicians have only one hemisphere :). On the other hand, as I already said, I am all for using whatever additional means we can to improve understanding, both in research, and in teaching.

      Best regards,

      Cristi

      Dear Cristi,

      I very much enjoyed reading your well-written and lucid essay, which provided me with food for thought. If I understand you right, you appeal to Wheeler's delayed choice experiment and observer participance to start with a case for it from bit, and law without law. Along the line though, you make a case for objective realism and a global consistency principle, and end by concluding for the necessity of an underlying it, so that the bits do not contradict. To quite some degree we are in agreement about the final conclusion.

      However, I have always been puzzled by the significance and interpretation attached to the delayed choice experiment. Does it tell us something new about the conventional view of quantum theory, which we already did not know without this experiment? For instance, if we could strictly conclude observer participance from here, would it not rule out `observer independent' reformulations/modifications such as Bohmian mechanics and GRW? But we know that these latter two theories are still in the reckoning. [You might enjoy looking up the proceedings of the recent Bielefeld conference `Quantum theory without observers' available at http://www.mathematik.uni-muenchen.de/~bohmmech/bielefeld/videos.html ]

      In any case the above is a point for discussion. I admire the courage and passion with which you have written your essay and wish you all the best.

      Tejinder

        Dear Prof. Singh,

        Thank you very much for reading and commenting.

        You said "I have always been puzzled by the significance and interpretation attached to the delayed choice experiment. Does it tell us something new about the conventional view of quantum theory, which we already did not know without this experiment?"

        I think that Wheeler's delayed choice experiment doesn't say something that is not implicit in the known experiments. Its great merit is, I think, pedagogical: it emphasizes a feature which, otherwise, is ignored and rolled from one corner of the mind to another, to avoid confronting it. The essence is that what happened in the past depends on how we prepare the measurement device now. Wheeler liked the spectacular conclusion of the observer participance, probably because he liked his conclusion of 'it from bit'. I think we can limit this to the experimental setup, rather than extending it to the observer (although the observer chooses what to observe). He wanted to conclude that this proves there's no 'it', and 'it' is inferred from the 'bit', while I prefer to restore reality, the 'it'. My claim is that 'it' is something that prevents 'bits' from contradicting one another, a 'reality check'. But, the price to restore realism is to make it dependent on the context, and by this I mean future measurements. I like to look at this as a 4D universe, in which events at various positions and moments in time constrain one another (global consistency). In quantum phenomena, when we develop the events in time, the 4D constrains manifests as if the present depends on what we measure in the future (delayed initial conditions).

        Does this dependence of the past on the future measurements persist in realistic approaches like GRW and deBroglie-Bohm? I think it does, and I would refer here to Bell's and Kochen-Specker's theorems. Some claim realistic approaches like dBB are ruled out by such theorems. I don't think so, but the price is the same: to admit that the experimental setup constrains the past. Otherwise, the dynamics of GRW and dBB is not contradicted. In fact, I think that even the unitary evolution, as in the Schrodinger's equation, can be maintained without discontinuous collapse, if we accept that the initial conditions are delayed, or that they have to include the future experimental setup (superdeterminism). No reference here to observers, but only to measurement device. Restoring unitary evolution in the theory (without tricks like "unitary evolution is preserved, if we include all the branches corresponding to the different outcomes") is much more difficult than in modified dynamics or hidden variables, because unitary evolution is much more rigid. But even if there is no proof that unitary evolution is preserved, at least we know that it is not obligatory to be violated - the collapse is not necessarily discontinuous.

        Thank you for the link to he conference Quantum theory without observers III. Currently I am watching The Quantum Landscape 2013.

        Best regards,

        Cristi

        Christinel,

        If given the time and the wits to evaluate over 120 more entries, I have a month to try. My seemingly whimsical title, "It's good to be the king," is serious about our subject.

        Jim

        Hi Cristi,

        Talking about the observer and Quantum mechanics, I have secured a unique definition of the term "observer" here What a Wavefunction is.

        Pls read through.

        Meanwhile am getting back to you on your essay in a while. I have a download.

        Chidi Idika

        Dear Chidi Idika,

        Thank you for the link. I look forward.

        Best regards,

        Cristi

        Dear Christnel

        Thanks for the essay. I think what you have written, "I argue that there is in fact an interplay between it and bit. The requirement of global consistency leads to apparently acausal and nonlocal behavior, explaining the weirdness of quantum phenomena" might have a solution in my posted essay but in some how differently.

        The "world" or I say as "digital nature" i.e. "It" can be defined as is a product of two inverse sets of ultimately "bits". Therefore some new fundamental constants may emerge to explain that "world" or "digital nature" simply as an interplaying of "It" and "Bits" in cycles.

        Thanking once again.

        Regards

        Dipak

          Dear Dipak,

          You observed well that I propose as a solution to the apparent acausality and nonlocality encountered in quantum mechanics, the global consistency principle. Thank you for directing me toward your essay, in which, I understand that you also proposed a solution.

          Best regards,

          Cristi

          Dear Cristinel

          Indeed, we are in agreement. Thanks for the link to the articles the idea goes more less in that direction. But that idea is limited, I have a wider view that encompasses both the notion of particle and of wave.

          Best Regards and good luck in the contest

          Israel

          Dear Cristi,

          Your essay has captivated my attention.

          You agree with me that such a "zero axiom" should exist. This is what I suggest in my essay. I called it the principle of duality, which handles the contraries. What do you think about ?

          A question : what do you think if we rename « quantum mechanics » by « quantum and wave mechanics » ?

          best regards

            Dear Amazigh,

            I am glad you liked the axiom zero. About renaming « quantum mechanics » by « quantum and wave mechanics », this sounds a good idea. For some reason, one tends to forget about the waves. Looking forward to read your essay.

            Best regards,

            Cristi

            Hi Cristi,

            Yesterday evening I returned from holidays. I have just finished to read your beautiful Essay which enjoyed me very much. Congrats. I appreciated that you emphasized the important contribution by Zel'dovich and Starobinski to black hole radiation. Although Hawking cited them in his original famous paper, they are often neglected by researchers who study black hole thermodynamics. Another fundamental contribution on quantum fluctuation is due to Parker, who preceded both Hawking and Zel'dovich's group on this important issue.

            In any case, I am going to give you an high score.

            Cheers,

            Ch.