Dear prof. Tejinder singh,

Thanks for producing an excellent essay which is highly thought provoking and equally original in its content. I am beginning to wonder whether both GTD/CSL and the Copenhagen interpretation of QM are 'diametrically opposite' views; where GTD/CSL move from past to future as in classical physics and hence give priority to It in QM, whereas Copenhagen interpretation moves from future to past and give priority to Bit although both describe the same reality from opposite ends/ directions. The Copenhagen interpretation due to its stance is 'queer' in the sense that it thinks of controlling past from the future and thereby controlling the future itself which irritates any classical physicist, but GTD/CSL do not give credence to such views and in this sense preferable.

Best of luck in the contest,

Sreenath

Resp Prof Tejinder sir,

I replied your COMMENTS put on my essay yesterday. I hope you will see those and discuss...

Best Regards

=snp

Dear Sreenath,

Thank you for your kind remarks. I broadly agree with your viewpoint about Copenhagen versus CSL/GTD. It all comes down to whether we are willing to accept probabilities as fundamental in a system which does not have an underlying sample from which to select.

Regards,

Tejinder

5 days later

Many thanks for your reply and comments over at my essay Tejinder. I've replied. Still thinking about the threefold way while reading other essays. Certainly got me thinking!

All the best for the contest & nice to "meet" you!

Antony

You argue against probabilities having a 'fundamental, irremovable status in quantum theory'.

I think the layman's view of what your saying is that probabilities are not fundamental to the Cosmos, and there is therefore an absolute reality that we can know completely.

But the It-Bit question does not only pertain to the measurement of quanta, or the probabilities thereof - even if this is what inspired Wheeler to make his statement.

It is a much bigger question than that.

Even if the emergence of random outcomes can be explained in a variety of ways, the nature of Bit remains unchanged: It is information, and ultimately - even in mathematics and physics - it defines the Observer's patch of reality at a given moment.

Regardless of how we ultimately account for the phenomena of the quantum world, there will still be a greater reality beyond human cognition; the observer does not interact with the whole field of reality regardless of how probabilities emerge. Mathematics is the projection of the human mind on to the Cosmos - and it is only bits!

Though it is doubtless critical to investigate quantum reality as thoroughly as you do, it is also necessary to define the relationship between the Observer and the field of observation. What we must ask is: 'Why do Bits 'match' Its so consistently at every instant of evolution?'

There is indeed cause to doubt which quantum model should be adopted, a point you make very thoroughly - but even if we could describe the quantum world in perfect mathematical language, we would still have only described some small part of our Cosmos perfectly; and we would nonetheless still be involved in our distinctive human Cosmos ... one that displays a continuous correlation between Bit and It over the course of evolution.

As you can probably tell, this is one of the strands of my essay.

Believe me, I found your work highly informative and very interesting, and my objections only relate to the implicit parameters within which you are framing your conclusions - ie: that adopting one quantum model over another causes the concept of It-Bit duality to 'vanish into thin air'.

I believe that a definition of Information underlies your thought as it does mine, and that it would be very positive if your parameters were expanded so that you might precisely define the Correlation of Bit to It, as I do.

I am eager to hear your feedback, of course, and to know what you think of my essay.

All the best!

John

Dear prof. Tejinder singh,

It is disheartening to know that such a beautifully written essay as yours is rated so low so far in the essay contest and I have decided to give you a shot in the arm by giving you maximum honors.

Best of luck in the essay contest.

Sreenath

Dear John,

Thank you for your constructive criticism which I fully accept: we have dealt with the it-bit question only in the limited context of quantum theory, and undoubtedly the scope and context of the matter-information relation is much larger. Perhaps it could be said we stayed within these limits because our training and expertise lies here. We might be out of our depth trying to address the larger question.

I shall definitely read your essay very soon, and leave a comment on your page. Till then, here are my layman views on the issue, when one steps out of the quantum theory domain. I want to divide the issue into two parts: (i) classical world, without making a reference to observer/mind/consciousness, (ii) same as (i) but with the observer included.

(i) I feel one can give here a precise match here between the material world [spacetime-matter] and the mathematical description of the properties of the material world [which i would like to call knowledge/information]. Honestly, here information seems to me to be just a big blown up word about what physicists do all the time: develop physical laws to mathematically describe properties and evolution of the material world. Here it seems rather apparent to me that bit follows from it.

In making the above physicist picture, we pretend that such a description exists without the observer playing a key role [objectivism], except that of someone who somehow grasps an understanding of the physical world and then presents it objectively as if the observer never existed.

(ii) including the observer / mind / consciousness: But I agree that this is only a pretend, and the question as to how the mind processes information, and in so doing relates to the physical world, must be understood. I agree that here the it-bit relation is non-trivial and not understood. Personally I feel we are not ready to answer these questions: we do not really understand thinking, nor do we understand understanding! But yes I do very much welcome attempts to explore this domain - maybe it will intimately involve interconnections between physics and neurobiology, and will spell out the limits of human information processing. I think this sort of reasoning overlaps with what you say above.

So those are my two cents :-) Thanks again for putting my essay in perspective - I was enlightened to learn from this contest that so many essays here address the larger picture you emphasize, including yours, which i will see soon.

Best regards,

Tejinder

    Dear Tejinder,

    Your essay is impeccable and well grounded. There are indeed many theoretical rats to smell as things currently stand. Your conclusion that Bit is from It also follows on one condition, which if correct will be a fatal oversight to that conclusion. Bit is short for any binary choice.

    Bizarre as it may initially appear, Is existence/non-existence then one of the binary choices available? If not, why not if the universe as a whole exhibits this choice? (if our cosmology is correct). Can this Bit be denied other Its, if the universe is not denied this choice? If yes, then non-existence is one bit that does not require any It to carry it. Again, what other Bit can lie below this Bit? Would it not occupy the "very, very deep bottom" as Wheeler says? If there is actually some primordial substance, can a fundamental discrete It come from another It? Would it rather not be derived from this Bit mentioned?

    So when you say, "...we believe that 'it from bit' is not a real option. 'Bit' always refers to a pre-existing 'it'", I can understand because obviously, the Binary choice I mention above does not come into your reckoning, or if it did, you don't want it included in the list of available Bits. As I claim in my essay however, it is likely that it is that Bit that will make "all problems evaporate" and not the contrary.

    *Mind you, a few in this community have come to agree that this Bit should not be excluded from our list of Bits, with Ian Durham introducing another view (trying to find an escape route) in that he says probability can again dog that Bit, i.e. an It can hover between existence and non-existence.

    I enjoy dialectic, so pardon my barrage of questions.

    Whatever, your essay is a collector's item on how to rectify deficiencies in Quantum theory.

    My essay is here as well, you may take a look.

    Cheerio,

    Akinbo

    Thank you Akinbo, for your kind appreciation, and also for your comments, which perhaps bear similarity with those by John Selye just above. I agree to the importance of the observer/existence aspect when the matter-information relationship is considered in its broadest perspective. My response would perhaps again be somewhat along the lines of the response to John's comments.

    I hope to see your essay soon.

    My best wishes,

    Tejinder

    Dear Angelo,

    You wrote an excellent essay to introduce your RMP paper and more.

    I don't really understand why your work contradicts the "it from bit" philosophy.

    As you write in the RMP paper, QM is a theory of measurements and seems to have "nothing to say about the world as it is". So, in the range of validity of QM, the "bit from it" makes no sense. On the other hand, QM says a lot about observer participancy and the existence of objects, and finally about the "it".

    Is it that you reject QM in the microrange? In that case, you would have to explain many exotic quantum properties, from non-locality to entanglement and contextuality, am I right?

    Best wishes,

    Michel

      Dear Michel,

      Thank you for your kind appreciation and interesting comments.

      To put in perspective the remark you quote from our RMP paper we reproduce here the entire paragraph in which that sentence appears:

      "

      Quantum mechanics, in its standard textbook formulation, refers only to the outcomes of measurements, but it has nothing to say about the world as it is, independently of any measurement or act of observation. This is a source of serious difficulties, which have been clearly elucidated, e.g., by Bell (1990): ''It would seem that the theory is exclusively concerned about 'results of measurements,' and has nothing to say about anything else. What exactly qualifies some physical systems to play the role of 'measurer'? Was the wave function of the world waiting to jump for thousands of millions of years until a single-celled living creature appeared? Or did it have to wait a little bit longer, for some better qualified system . . . with a Ph.D.?''

      "

      This is intended as a criticism of the Copenhagen interpretation. When we say quantum mechanics is a theory of measurements, and has nothing to say about the world as it is, it is intended to mean that according to the Copenhagen viewpoint, unless a measurement is made [and information acquired] no definite reality can be ascribed (i.e. `has nothing to say about the real world') to the properties of objects [because the outcomes of successive measurements are only probabilistic, and not predictable]. This is `it from bit' suggested by the Copenhagen interpretation: make a measurement, gain statistical information (bit), and deduce the properties of the `it'. The it is claimed to be ill-defined without the bit coming first.

      We are saying this is very much tied to the Copenhagen interpretation, which interpretation we find unsatisfactory, for reasons which you saw outlined in the essay. We highlight that indeed there are interpretations/modifications of QM which explain the collapse of the wave-function and the measurement problem, without invoking observer participancy. Here the it comes first [it being the particle / wave-function / matrix] and is well-defined even before the measurement is made. Measurements give information (bit) about this preexisting it; hence bit from it. This runs contrary to the Copenhagen interpretation.

      We fully accept QM in the microrarnge. The Copenhagen interpretation, as you will agree, is not a statement about the microrange, but rather about the process of measurement. All interpretations/modifications of QM are in agreement in the microrange. The differences are only in the understanding of the measurement process and of the quantum-classical transition.

      Thank you once again for your kind interest in our work,

      Best,

      Authors

      Thanks Tejinder,

      I appreciate your input - it does seem to me that the paradigm I've created does put your option (ii) in a context that makes the Cosmos fully accessible to classical, Bio-, and Neuro-Physics. I did rate your essay highly, and am looking forward to studying it again.

      I look forward to hearing from you soon on my page,

      All the best,

      John.

      Angelo, Saikat, & Tejinder,

      I am somewhat familiar with Bohm QM, less so with dynamic collapse and I will have to read on trace dynamics. I did read something a while back about how dynamic collapse runs into some difficulties.

      Bohm QM works well enough for systems with quantum observables that have a direct correspondence with classical mechanics. Bohm's QM does not work very well without a classical-quantum correspondence. BQM contrary to what is commonly said does work in a relativistic setting. You can write the Klein-Gordon equation in real and imaginary parts, just as with the Schrodinger equation. What becomes troublesome is when you try to do interacting QFT. There is no natural ladder of states from which to describe the production of massive particles. As a result there is no workable BQM form of QED.

      These approaches to QFT, which are really forms of quantum interpretations, are minority reports. I did some work on quantum chaos where I used BQM. I used it because it is close to a classical description and is convenient for working Hamiltonian chaos. The response was not good, largely because of the Bohm part. I kept trying to argue that there is nothing erroneous with the writing the wave function in polar form, separating the Schrodinger equation into real and imaginary parts and so forth. BQM is admittedly weak in some respects, but it is not wrong. I don't think BQM can replace standard QM, nor do I think it is likely the others will either. Yet they have their niche.

      Cheers LC

        Dear Lawrence,

        Thank you for your interest in our work and for reading our essay.

        We do not quite understand what you mean by your remark:

        "Bohm QM works well enough for systems with quantum observables that have a direct correspondence with classical mechanics. Bohm's QM does not work very well without a classical-quantum correspondence."

        What we have said in our essay is that

        "In this theory, a system of N non-relativistic particles is described by a wave function which lives on configuration space, and by the actual positions of the particles. The positions evolve according to a 'guiding equation' which depends on the wave function, while the wave function itself obeys the Schro ̈dinger equation."

        This, along with the quantum equilibrium hypothesis, completely defines the theory. Of course the Hamiltonian must be prescribed by hand, and yes there one relies on experience from classical physics, but that then is true as much for standard QM and dynamic collapse as for BM. With the above structure, BM reproduces all the results of standard QM. And it does better, because the collapse of the wave-function / the projection postulate are not put in by hand in an ad hoc manners as a recipe to explain outcomes of experiments.

        We agree that one can easily write down the one particle / non-interacting relativistic BQM. But that is trivial isn't it? We always had the interacting relativistic QFT in mind.

        If by standard QM you mean the one with Copenhagen interpretation, we believe it is an incomplete theory. It does not explain what happens during a measurement - it merely postulates collapse of the wave-function without prescribing a mechanism for the collapse. We believe the least one would have to do to complete the theory is to adopt the many-worlds interpretation or BQM. Personally, we have difficulties with many worlds since we do not see how probabilities and the Born rule can come about in MW. So we would prefer BQM over MW.

        Alternatvely, collapse of the wave-function might be explained dynamically - we think this issue will be settled by experiments, because dynamic collapse theories make different predictions from BQM / standard QM in the yet untested mesoscopic domain.

        With our best regards,

        Authors

        Angelo, Saikat, & Tejinder,

        The information as embodied in particle properties (which can be thought of as internalized rules of behavior, the expression of laws of physics) in a self-creating universe must be the product of a trial-and-error evolution. If fundamental particles have to create themselves, each other and particles only exist to each other if and for as long as they interact, then particles, particle properties, 'its' must be as much the source as the product of their interactions, both cause and effect of a continuous energy / information exchange, then information only can evolve, become information when molded into material particles and tested in actual particle interactions: only such information survives which enables its embodiments to survive, to manifest themselves as real particles. So I don't see how you can have one without (before?) the other, how one can be more fundamental than the other.

        Regards, Anton

          Bohm QM is basically the Schrodinger equation split into a real and imaginary part. There is the Hamilton-Jacobi equation for the real part that includes this quantum potential term

          -∂S/∂t = H - (ħ^2/2m)∇^2R/R

          for the wave function ψ = Re^{-iS/ħ}. That quantum potential is associated with the guidance equation. There is an imaginary part which is formally a continuity equation. None of this is wrong exactly, but I think it is weak. The one problem is that it depends upon classical variables, where we know there are quantum observables that have no classical analogue. In addition quantum mechanics with its complementarity of observables permits one to work exclusively in the position or momentum representation. This is a halving of the number of degrees of freedom a theory needs. Bohm QM brings back the full phase space with {p, q} variables.

          I think this is potentially useful for quantum chaos, for the classical-like structure of this theory is I think better adapted to the techniques in classical perturbation theory and looking at KAM theorem results on puncturing invariant tori. The classical-like particle, called the beable, then traces out chaotic motion. Of course to my way of thinking this beable is really just a mathematical fiction of sorts. It is a gadget used to compute scarring in quantum chaos.

          The BQM is a sort of interpretation. It is meant to get around the cut-off problem with Copenhagen interpretation. MWI has been worked out with Born theorem. I think the big open question is contextuality. An observer is free to orient their Stern-Gerlach apparatus by choice. This selects the eigenbasis of a measurement, but the Kochen-Specker theorem tells us that QM has no such contextuality; QM treats all bases equivalently up to a unitary transformation. So this eigen-splitting of the world in MWI, where different observers record different results, has some sort of implicit contextuality.

          It is my general observation that QM interpretations that are meant to give some dynamics to a measurement, such as Bohm's QM does by tying things closely to classical physics, runs into their own set of difficulties. Quantum interpretations in my opinion are devices that can be employed for different problems, where some interpretation turns out to be more applicable. Now there is the rise of Qubism, which ties QM to Bayes' theorem, but as near as I can tell this ends up being just another interpretation.

          Cheers LC

          Dear Angelo, Saikat and Tejinder,

          I enjoyed reading the overview of the three alternatives to orthodox quantum mechanics. I did not previously know much about trace dynamics, so it was good to find out a bit more about it. It would have been nice if the experimental tests hinted at in the article would have been described a little, possibly including an expected date (if known) for when they are expected to be performed. Also, one might ask if it is possible to motivate the theories a little more. Obviously nature does not need to heed our prejudices, but it would be nice if she could be understood at the most fundamental level in a way that makes sense.

          I wish you all the best,

          Armin

            Dear Anton,

            We are not sure we understand your remarks. Perhaps you refer to a very broad context as to how information relates to matter, interactions and space-time. We have addressed only one aspect of that very broad issue: how the interpretation / understanding of probabilities in quantum theory can dictate the primacy of it over bit or vice versa.

            Best regards,

            Authors

            Dear Armin,

            Thank you for reading our essay and for your comments.

            The experiments have been going on since the nineties, and have put useful bounds on the theories. If you like you could see our recent review article in

            Reviews of Modern Physics 85 (2013) 471

            also available at

            http://arXiv.org/abs/arXiv:1204.4325

            where we discuss these experiments in detail, as also the motivations for the theories.

            Best regards,

            Authors

            Dear Dr. Singh,

            Your argument for an underlying deterministic basis for quantum theory is novel and very well presented!

            Using a Bohmian approach necessitates that there is an underlying quantum wholeness in which absolute probabilities are defined for every possible outcome. One way to approach this is by using quantum information theory.

            The emergence of classical spacetime from coarse graining classical matrix dynamics thus depends upon the conditional entropy of the observer. The measurement process arises out of her ignorance that this is just another aspect of dynamic evolution. Essentially, she erases the entanglement information of the underlying quantum wholeness. (See my essay "A Complex Conjugate It and Bit".)

            In this way, paralleling your theory, the "it" arises from the "bit".

            Best wishes,

            Richard