Dear Philip,

For completeness, kindly indulge me an answer to the question even though it may not be your essay topic. But being a professional I will value your opinion:

Is it being implied by the relational view of space and as suggested by Mach's principle that what decides whether a centrifugal force would act between two bodies in *constant relation*, would not be the bodies themselves, since they are at fixed distance to each other, nor the space in which they are located since it is a nothing, but by a distant sub-atomic particle light-years away in one of the fixed stars in whose reference frame the *constantly related* bodies are in circular motion?

You can reply me here or on my blog. And please pardon my naive view of physics.

Accept my best regards,

Akinbo

    It's trivky to answer questions in terms of Mach's principle because Mach only gave a vahue idea of what he meant and it does not correspond to the way we think about gravity and inertia since general relativity. I can only really answer the question in terms of what we know now.

    In general relativity it is not correct to say that rotation is measured relative to distant stars. Rotation is relative to a local inertial reference frame. In normal circumstances local rotation in an inertial frame is very close to the fixed frame defined by the distant stars but it does differ slightly due to the geodetic effect and frame dragging. This means that it is not really correct to talk about rotation in terms of direct relationships between objects at very large distances. Instead of the "action at a distance" idea of Newtonian mechanics we must now think in terms of matter affecting and being affected by the gravitational field whose effect propagates at the speed of light.

    However, there is still possibly some mileage to be had from relational ideas in quantum gravity at small scales.

    I agree fully with what Feynman said and it always influences my thinking. It is why I do not dismiss different ways of looking at things. For example I am always promoting the idea that string theroy and loop quantum gravity are not contradictory alternative ideas. They are more likely different (but incomplete) ways to look at the same things. The concept of dualities has become even more important in recent times and is a dramatic example of his thinking.

    Another side to this is that even different philosophical approaches can turn out to be equally valid. e.g. "It from Bit" vs "Bit from It", but I think that the "It from Bit" viewpoint is more useful in our current state of knowledge.

    Chris, I am sorry I am having trouble forming a good answer to this because I dont see clearly what you mean. As the sphere expands there is more information inside the volume and more area on the boundary. vice versa as it shrinks. I dont see where this poses a problem for the holographic principle. It is probably my misunderstanding of your point that is the problem.

    Phil

    I appreciate your reply and very sorry to be troubling you. Trying to know what you physicists have in mind. Answering the question in terms of what we know now:

    1)Between those two bodies where will the local inertial reference frame be located? In the middle point of the line joining them, being the only two local objects, there will still be no way of knowing of their rotation without reference to a third object. So in what frame will this rotation be observable? Note apart from that distant star these are the only two objects in the universe!

    2) Let us not assume that these two objects are bound by gravity. It may be electromagnetism or a string binding them. This is to avoid complicating the picture by geodesics and frame dragging. The question is how can we know they are rotating? We know this by experiencing centrifugal force. But then rotating with respect to what?

    It seems to me without preempting you that space may not be relational but substantial, don't you think? Then someone referred me to a talk by Paul Davies in which moving objects in space experience an Unruh effect.

    In the absence of any reference frame to distinguish circular from linear motion, then it appears we have only Newton's space to decide our reference frame? Or do you disagree? Where can you be located to observe the rotation if it is occurring?

    Thanks for your time. Much appreciated.

    Akinbo

    Gibbs,

    I have a few questions or comments/opinions if you will.

    Why are boundary conditions stressed? Yes, the surface area and Planck Unit-using formula say this is a relation between information and entropy, but I don't see the logical necessity of that function being at a particular point. I would think that such a fundamental looking math equation would describe a whole group of phenomenon, not just a particularly interesting black hole paradox. I'm getting at that maths being used for all region near this "boundary."

    Which leads me to note another peculiarity. You don't mention particles. I would think that they two would be fundamentally described with information, since it's appealing to think the same logic applied to black holes applies to all entities in the universe, big small or otherwise insignificant and completely ordinary.

    It was a very nice essay and showed two sides and gave a pretty thorough presentation or argument. Since such difficulties are arising when the best minds are working on these problems with strings and somewhat in the way you prescribed, and seem still not to be near resolution, I think a deeper assumption will be what breaks down. Hopefully this is before many physicists do!

    Appreciatively,

    Amos.

      Dear Philip,

      It was a privilege to read your essay, wherein you discuss many ideas at the very foundational level. Often you talk about the power of consistency. Let us consider the following three points in this context.

      (1) The energy-stress tensor is a redundant part of Einstein's equations as the material and the gravitational fields appear in the geometry through the metric field (see my essay in the present contest).

      (2) Recently it has been shown that the right hand side of Einstein's equations, i.e., the energy-stress tensor T^ik, has serious problems [arXiv:1204.1553].

      (3) The quantization of the right hand side of Einstein's equations, in a given spacetime, has yielded the interesting effects of the Hawking radiation.

      Do the requirements of the logical consistency then not render the Hawking results doubtful, which are obtained by using the stress-energy tensor?

      Best Regards.

      ___Ram

        Dear Ram, You have a very interesting essay. I also dispute some conventional wisdom concerning GR and the formulation of energy conservation, but not as radically as you. Good Luck, Phil

        Phil,

        I have the impression you are mixing up divergence with covariant divergence... I do not see anything in what you say that goes beyond what is written in all GR books about energy conservation in GR. There is a vast literature on this... The rest seems to me to be hanging on nothing ...

        carlo

          Dear Philip,

          One single principle leads the Universe.

          Every thing, every object, every phenomenon

          is under the influence of this principle.

          Nothing can exist if it is not born in the form of opposites.

          I simply invite you to discover this in a few words,

          but the main part is coming soon.

          Thank you, and good luck!

          I rated your essay accordingly to my appreciation.

          Please visit My essay.

          Carlo,

          As I am sure you know ordinary divergence and covariant divergence are simply related for vector fields

          [math]\sqrt{-g}J^\mu_{;\mu} = \frac{\partial \sqrt{-g} J^\mu}{\partial x^\mu}[/math]

          so the ordinary divergence theorem can be immediately translated to covariant form for vector currents. In what way then am I confusing divergence and covariant divergence?

          Please could you tell me which textbook treats energy conservation in covariant form without claiming that it works only in special cases? In particular can you tell me where my covariant formula for the energy current (or equivalent) is given by anyone else either in texts or papers, I will repeat it here because the equation editor mangled it in the essay,

          [math]J^\nu(\xi^\mu) = \xi^\mu T_\mu^\nu - \frac{1}{\kappa}(\xi^\mu G_\mu^\nu \xi^\nu\Lambda) \frac{1}{2}(\xi^{\mu;\nu}-\xi^{\nu;\mu})[/math]

          I am glad that you agree with my conclusions about energy conservation because I have been waging a one-man battle online for twenty years to convince people that energy conservation in GR works. I have been up against people such as Baez, Carroll, Carlip, Motl etc who all think that energy conservation does not work properly in GR. It would be very helpful if I could just reference a text book that agreed with me.

          As to your final statement, I am baffled. I have made a number of original points. If you don't agree with specific points that is one thing but to call it nothing just indicates that you have not understood.

          The boundary for the holographic principle can be any boundary. The information inside must be less than the area of the boundary. In the special case where the boundary is a black hole horizon, entropy is maximised and the information inside is equal to the area of the boundary. The holographic principle tells us that this is not just a bound but in fact the information can be determined from the state on the boundary. If that does not answer your question please clarify.

          About particles, in quantum field theory particles are fields are dual descriptions of the same quantised field. It does not matter if you think in terms of one or the other. Information is encoded in the spectrum of states whether you use the particle description of the field description.

          Thank you for your comments I have also enjoyed your essay

          Dear Philip,

          Hear is to you for pushing boundaries, my rating. Because, from my own level of view, the strongest hope is that of multiple quantization; all methods that seek to perfect it! For it seems to me the only way that something may emerge from nothing. To start with, the non-local CANNOT be information, It signifies the NOTHING. So at last the "it" has to define as the "nothing" for Wheeler's "bit" to emerge therefrom. There is no way we can START by presuming information!

          And should you have the time please take another look (and do rate) at my corner.

          All the best,

          Chidi

          Dear All

          A standard-issue big city all-glass high-rise stands across the street from my usual bus stop. When I look up the high-rise facade, I can see the reflections of the near-by buildings and the white clouds from the sky above. Even when everything else looks pretty much the same, the reflections of the clouds are different, hour to hour and day to day.

          After I boarded the bus, I rushed to get a single seat facing four others on a slightly elevated platorm. From my vantage point, I can't help noticing the shoes of the four passengers across from my seat are not the same, by either the make , the design, or the style, and that is true even when the four passengers happen to be members of the same family.

          I could change the objects of my fascination from shoes to something else, to buttons on the dresses for example, but I do not think the result would have been any different. Diversity or Uniqueness would still rule the day! (There is a delightful essay on the subject of uniqueness by Joe Fisher in this contest.)

          I am pretty sure people are fascinated by the diversity and the uniqueness in the world, when the other side of it is the inevitable boredom of sameness every time.

          However, we have a need to know where all this beautiful and enchanting diversity comes from. Borrowing Wheelerian phraseology of "How come the quantum?", I ask "How come the diversity?" A standard physics answer is "Entropy always increases." (I am not a physicist, and I don't know if that is the final answer.)

          Whenever I'm out of my depth, I go back to my theory of everything (TOE), which is a mental brew of common sense, intuition, gut, analogy, judgement, etc. etc. , buttressed when I can with a little thought-experiment.

          The thought-experiment is simple. Imagine cutting a circle into two precisely, identical, and equal parts. Practically, there is no way we can get the desired result, because one part will be bigger or smaller in some way.

          Physics - especially quantum physics - says it don't matter, do the superposition!

          But superposition is fictive, an invention like the Macarena dance, and it has given us a cat, alive and dead at the same time.

          I have heard that angels can dance on the tip of the needle, and now I'm finding out some of us can too!

          Cheers and Good Luck to All,

          Than Tin

          Dear Philip

          I enjoyed reading your essay. It was clarifying and well structured. The fact that the information is proportional to the area of a black hole seems to me weird but we must accept the math. To say that entropy and information are the same thing reduces the problem, in my view, to mere interpretation. In such case, I wouldn't bother to replace the it by the bit. This is what I discuss in my essay.

          Indeed, as you said, what our instruments measure is discrete units (or bits) but we can derive discreteness from continuity, as some authors have argued. Real numbers cannot be computed with bits. So we need to assume that the essence is the continuity and the discreteness its manifestation which is used to distinguish one event from another. Take for instance the case of a measurement of a time interval using a quartz clock. How would you know when an event starts and when it ends. Time cannot be discrete, but we have to cut the time interval at some point to delimit it. So when we say that an event occurred at 10 am what we are saying in fact is that the event started between 9.999999... and 10.00000...0001. We are indeed discretizing time although we know that time flows continuously, otherwise we would fall into inconsistencies.

          On the other hand, when we accept that information is proportional to the area of the black hole, the immediate consequence is the holographic principle; which assumes that the area has sufficient information to describe the apparently 3D world. Do you think that this principle is correct? What new physics can be extract from this principle?

          Finally, I'd like to invite you to read my essay and leave some comments. There I discuss about Wheeler's dream and propose a potential way to get out of the present crisis. They key is assuming

          Well, I'll be looking forward to hearing any comments you may have.

          Regards

          Israel

          Hi,

          A nice and thought provoking essay so I wanted to make some comments/leave some questions.

          On page 2 you give three examples of advances made by Maxwell, Einstein and Dirac based on the use of logical/theoretical consistency as each was trying to combine different regimes of physics (E with M for Maxwell, GR with SR for Einstein, and SR with QM for Dirac). The idea being that this type of use of logical consistency will be our best/only tool as we try to build a theory of QG. While I generally agree with this view point there are some works which have proposed ways to test for QG effects. In the article "Tests of quantum gravity from observations of γ-ray bursts" G. Amelino-Camelia, J. Ellis, N.E. Mavromatos, D.V. Nanopoulos and S. Sarkar, Nature 393 (1998) 763 it was proposed that high energy gamma ray photons would show anomalous dispersion based on their interactions with the space-time foam. Recently Robert Nemiroff and colleagues from the FERMI gamma ray space-observatory noticed the almost simultaneous arrival of three gamma ray photons of slightly differing energies after a trek of almost 7 billion light years. This observation if confirmed would put tight limits on the scale of the possible space-time foam. A popular level description of this can be found at http://phys.org/news/2012-08-spacetime-smoother-brew-knew.html. Also one of my co-authors has a paper where he proposes tests of QG gravity effects using delicate quantum experiments

          ("Universality of Quantum Gravity Corrections", Saurya Das and Elias C. Vagenas, Phys.Rev.Lett. 101 (2008) 221301; e-Print: arXiv:0810.5333 [hep-th]). Anyway given the hugeness of the Planck scale theoretical cleverness/consistency may be the best tool for advance but there are some possible ways to test these ideas.

          I like the holographic description and in some sense even Gauss's law has some holographic flavor to it -- the total charge in the bulk is determined by a quantity (electric flux) at the surface. One might also include the AB effect in this category -- the phase picked up by the electron at the "surface" (the closed path surrounding the solenoid) is determined by the magnetic flux in the bulk "volume" (the area bounded by the path in this case). I did have one question/comment about the statement " Information about the total electric charge, colour charge and weak - isospin charge thrown into a black hole is not

          lost." I see how this is true for a charged RN BH -- if the BH carries a charge +Q at some point it will preferentially radiate positive charges in order to achieve electric neutrality. However weak charges/interactions are a broken symmetry and color charges are confined. Thus for weak charges there is an additional e^{-m_W r} fall off to the potential and one can not so easily or at all formulate a version of Gauss's law. If one takes a very large sphere around an electron one can determine the net electric charge from the flux at the surface, but I'm not sure the same is possible for the weak charge. Similar arguments apply for the color charge but here due to confinement rather than symmetry breaking. Thus my question is "Is it possible to holographically describe weak charge in the context of BH evaporation and if so how does it differ from the electric case where the symmetry is un-broken?"

          Finally I note you have a discussion of energy of the gravitational field near the end of the essay. As you note this is a contentious issue. The orthodox view is there is no good local definition energy in the gravitational field and yet the Hulse-Taylor pulsar does lose energy due to the radiation of gravitational waves. In this regard I like very much Weinberg's discussion of this issue in his 1972 gravitation text. in chapter 7 section 6. In equaiton 7.6.5 Weinberg write down a quantity which he called the gravitational field EM "tensor" which I think is similar to or the same as the L&L pseudo-tensor. Weinberg gives a list of reasons (A thorough G!!) to think of this as gravitational field energy but in the end it is not a real/proper tensor. But next Weinberg defined a volume integral of this quantity from 7.6.5 and then turns it into a surface integral via Gauss's law to arrive at a global quantity which he then makes calculations to support as the global energy and momentum of the gravitational field -- this energy and momentum of the gravitational field is given finally via 7.6.21. This then would seems to be exactly in the spirit of the holographic view of gravity -- the exact degrees of freedom/gravitational field energy in the bulk are not as crucial as the globally defined quantity which is spread over the surface. In any case my reading of this is that Weinberg very much wants to define a energy-momentum of the gravitational field. The most rigorous think he arrives at is a surface integral 7.6.21 which seems then to be in accord with the holographic principle.

          Best,

          Doug

            Doug, thank you for your detailed points, and thanks for reminding me about the Fermi results. I mentioned that in an earlier essay. It would be much more important if they measured a dispersion rather than setting a limit but we cant tell nature what to do. I certainly agree that every effort should be made to look for QG effects both in the lab and in cosmology. I want to be optimistic about it but I feel more pessimism. Luckily I do feel optimistic that QG theory is still progressing fast and perhaps when it is understood there will be a clear prediction that can be tested.

            Concerning the holographic nature of weak and strong nuclear forces I think the principle still holds. The conservation law and its holographic nature depends on the symmetry of the underlying equations and works regardless of the solution. If the solution breaks the symmetry it does not change things. It just makes it harder to see it directly. The colour charge of a blackhole may be impossible to observe due to confinement but you can place a surface round a single quark and measure its colour on the boundary. As far as I know these principles carry over from classical to quantum but I agree that this needs to be shown. Obviously we are only talking about theory so it is the principle that counts. We cant hope to measure this directly.

            Of all physicists Weinberg is the one I find most reasonable and wise. His analysis of energy in GR is one of the best even if it uses pseudotensors. The equation I have given does the same job in covariant form and energy and momenta can be understood as belonging to a vector space acted on by a dual resprsentaion of the diffeomorphism Lie algebra. It is surprisingly hard to convince people that it makes sense and then when I finally succeed people just tell me that it is all known textbook stuff.

            I think you wrote a good essay, although it is a little math-intensive. I liked the "acataleptic" vocabulary usage: I got to teach my computer a new word! However, I'm not so sure about how certain you are about uncertainty.

            Please check out my essay: All Your Base Are Belong To Math.

            - Kyle Miller

            Dear Philip,

            We are at the end of this essay contest.

            In conclusion, at the question to know if Information is more fundamental than Matter, there is a good reason to answer that Matter is made of an amazing mixture of eInfo and eEnergy, at the same time.

            Matter is thus eInfo made with eEnergy rather than answer it is made with eEnergy and eInfo ; because eInfo is eEnergy, and the one does not go without the other one.

            eEnergy and eInfo are the two basic Principles of the eUniverse. Nothing can exist if it is not eEnergy, and any object is eInfo, and therefore eEnergy.

            And consequently our eReality is eInfo made with eEnergy. And the final verdict is : eReality is virtual, and virtuality is our fundamental eReality.

            Good luck to the winners,

            And see you soon, with good news on this topic, and the Theory of Everything.

            Amazigh H.

            I rated your essay.

            Please visit My essay.

            Late-in-the-Day Thoughts about the Essays I've Read

            I am sending to you the following thoughts because I found your essay particularly well stated, insightful, and helpful, even though in certain respects we may significantly diverge in our viewpoints. Thank you! Lumping and sorting is a dangerous adventure; let me apologize in advance if I have significantly misread or misrepresented your essay in what follows.

            Of the nearly two hundred essays submitted to the competition, there seems to be a preponderance of sentiment for the 'Bit-from-It" standpoint, though many excellent essays argue against this stance or advocate for a wider perspective on the whole issue. Joseph Brenner provided an excellent analysis of the various positions that might be taken with the topic, which he subsumes under the categories of 'It-from-Bit', 'Bit-from-It', and 'It-and-Bit'.

            Brenner himself supports the 'Bit-from-It' position of Julian Barbour as stated in his 2011 essay that gave impetus to the present competition. Others such as James Beichler, Sundance Bilson-Thompson, Agung Budiyono, and Olaf Dreyer have presented well-stated arguments that generally align with a 'Bit-from-It' position.

            Various renderings of the contrary position, 'It-from-Bit', have received well-reasoned support from Stephen Anastasi, Paul Borrill, Luigi Foschini, Akinbo Ojo, and Jochen Szangolies. An allied category that was not included in Brenner's analysis is 'It-from-Qubit', and valuable explorations of this general position were undertaken by Giacomo D'Ariano, Philip Gibbs, Michel Planat and Armin Shirazi.

            The category of 'It-and-Bit' displays a great diversity of approaches which can be seen in the works of Mikalai Birukou, Kevin Knuth, Willard Mittelman, Georgina Parry, and Cristinel Stoica,.

            It seems useful to discriminate among the various approaches to 'It-and-Bit' a subcategory that perhaps could be identified as 'meaning circuits', in a sense loosely associated with the phrase by J.A. Wheeler. Essays that reveal aspects of 'meaning circuits' are those of Howard Barnum, Hugh Matlock, Georgina Parry, Armin Shirazi, and in especially that of Alexei Grinbaum.

            Proceeding from a phenomenological stance as developed by Husserl, Grinbaum asserts that the choice to be made of either 'It from Bit' or 'Bit from It' can be supplemented by considering 'It from Bit' and 'Bit from It'. To do this, he presents an 'epistemic loop' by which physics and information are cyclically connected, essentially the same 'loop' as that which Wheeler represented with his 'meaning circuit'. Depending on where one 'cuts' the loop, antecedent and precedent conditions are obtained which support an 'It from Bit' interpretation, or a 'Bit from It' interpretation, or, though not mentioned by Grinbaum, even an 'It from Qubit' interpretation. I'll also point out that depending on where the cut is made, it can be seen as a 'Cartesian cut' between res extensa and res cogitans or as a 'Heisenberg cut' between the quantum system and the observer. The implications of this perspective are enormous for the present It/Bit debate! To quote Grinbaum: "The key to understanding the opposition between IT and BIT is in choosing a vantage point from which OR looks as good as AND. Then this opposition becomes unnecessary: the loop view simply dissolves it." Grinbaum then goes on to point out that this epistemologically circular structure "...is not a logical disaster, rather it is a well-documented property of all foundational studies."

            However, Grinbaum maintains that it is mandatory to cut the loop; he claims that it is "...a logical necessity: it is logically impossible to describe the loop as a whole within one theory." I will argue that in fact it is vital to preserve the loop as a whole and to revise our expectations of what we wish to accomplish by making the cut. In fact, the ongoing It/Bit debate has been sustained for decades by our inability to recognize the consequences that result from making such a cut. As a result, we have been unable to take up the task of studying the properties inherent in the circularity of the loop. Helpful in this regard would be an examination of the role of relations between various elements and aspects of the loop. To a certain extent the importance of the role of relations has already been well stated in the essays of Kevin Knuth, Carlo Rovelli, Cristinel Stoica, and Jochen Szangolies although without application to aspects that clearly arise from 'circularity'. Gary Miller's discussion of the role of patterns, drawn from various historical precedents in mathematics, philosophy, and psychology, provides the clearest hints of all competition submissions on how the holistic analysis of this essential circular structure might be able to proceed.

            In my paper, I outlined Susan Carey's assertion that a 'conceptual leap' is often required in the construction of a new scientific theory. Perhaps moving from a 'linearized' perspective of the structure of a scientific theory to one that is 'circularized' is just one further example of this kind of conceptual change.