Armin, I was coincidentally reading your essay today so I am happy to find your comment here.

The examples of Maxwell, Einstein, Dirac and Higgs are some of the best examples from history of how logical consistency has been used by theorists. I agree that the circumstances have changed in that further experimental data is lacking for quantum gravity, but that is precisely why consistency is now so important.

I do think that whatever we conclude will eventually be confirmed by observation but the time scale is goinf to be much larger because it is difficult to reach the energy scales required. Nevertheless there are people looking for possibilities in quantum gravity phenomenology.

Of course it would be better if some theory could shed light on dark matter or inflation in a way that we could test, but there are people looking at that too. It is not a choice of one or the other. For some reason we seem to be able to make more promising progress on questions that relate to the highest possible energies at this time. Perhaps that will change.

"Why do you think is it the case that over the last 20 years, the application of necklace lie algebras has not been taken up by the string theory community?"

This is an interesting question but I think the simple answer is that I have not found a convincing enough case to get them interested. There are so many ideas around that might be important that it is hard to get people interested unless there is something really obvious that makes it look important.

Sometimes a mathematical idea can hang around for years looking interesting before people find the right way to use it. A good example is twistor theory invented by Penrose years ago. Most people gave up on it but a few kept going. Andrew Hodges developed a complex diagramatic system for physics based on twistors but nobody paid any attention until Witten applied twistors to string theory a few years ago. A group of theorists then started to use it on super Yang-Mills theory. According to Nima Nima Arkani-Hamed they started to develop a new diagramatic approach for this and then noticed that some of their diagrams looked like the ones drawn by Hodges whose theory they could not really understand at that time. So they looked at some of his more complex diagrams and asked what they would mean in their new theory of super yang-mills. Suddenly everything made sense and they were able to move forward much quicker.

Now they understand it all in terms of invariants of an infinite dimensional Yangian symmetry which had previously been used to understand integral models of spin chains. These things are tantalizingly close to my necklace lie algebras but so far no cigar. It would certainly be amusing if someone wrote down the same definitions as I used twenty years earlier as a solution to the corresponding problem in string theory, but it is more likely that it will be something else

I don't think I had heard of him before, thanks for the pointer.

Philip,

Thank you for answering my questions. Your answers were well thought out and went in a completely different direction from what I imaged. I was very surprised by the black holes created by crossed information beams. I would have bet against you stating that the second law of thermodynamics survives nearly to the plank scale. I am glad I asked these questions. It looks like your essay is doing well, remember us little people when you win.

Jeff

Philip,

I very much enjoyed reading your essay. Your application of Lie algebras to formulate how spacetime emerges from quantized charges of the symmetry hidden in holography is very intriguing.

It is also possible to consider the momentum/energy information in a black hole and the lost spacetime information as reciprocal measures of entropy. In this way spacetime emerges from the hidden symmetry of entanglement entropy via the conditional entropy of the local observer.

Conversely, a compactification of spacetime leads to a dimensional collapse from 4D to 2D (CFT) to 1D in the bulk towards a point singularity. (See my essay "A Complex Conjugate Bit and It".)

Best wishes,

Richard Shand

    Hi Philip,

    Terrific to see a way to discretize String Theory. Now if only we could find proof of String Theory... :)

    You wrote:

    1. "The lesson to be taken from holography is that there is a huge hidden symmetry in physics that nobody has yet appreciated."

    What do you think of Bobylev and Vilasi's Projective Invariance as a candidate symmetry? Their paper is not well-known as they published in an obscure journal that soon went under. Luckily, it survives in cyberspace.

    2. "Some observational input on phenomenology of quantum gravity would help but for now everything we can measure is adequately explained by the physics of quantum mechanics, general relativity, thermodynamics, and the standard model of particle physics."

    Quite an optimistic view in the face of multiple foundational cosmological issues regarding Dark Matter, Dark Energy, Inflation, quasar energies, CMB anisotropy, etc! In my essay, Software Cosmos I work out a holonomic model (in the sense of David Bohm and Basil Hiley) that utilizes the Projective Invariance symmetry to address some of these cosmological problems. Hope you get a chance to take a look...

    Hugh

      Hugh thanks for your comments and questions.

      I had not seen the paper of Bobylev and Vilasi. It should be interesting in the context of the systems they describe. The symmetry appears to use 2D Mobius transforms which are part of conformal invariance. This is a very important symmetry in quantum field theories of massless particles. In super yang mills theory there is a dual conformal invariance which conbines with ordinary invariance to give a larger symmetry which can be used to solve the theory in the planar limit and perhaps beyond. In quantum gravity an even larger symmetry is needed to explain holography but projective mathematics surely plays its part.

      I agree that Dark Matter, Inflation etc are big issues that need to be solved but they have not been much help to quantum gravity and I do not mention in my essay.

      I will take a look at your essay to see how you use projective invariance in relation to these problems.

      Phillip

      the way I like to do physics is to have clearly stated and motivated principles, and derive all physical consequences from them, as in a mathematical theorem.

      My best regards

      Mauro

      Dear Philip Gibbs:

      You quote Wheeler: "Nothing else in our multifarious universe is fundamental, he conjectured. Space and time, locality and causality". It would be the same if "time" is just a remnant word, from which mankind forgot its meanings as Einstein suggested is one of the pre-scientific concepts, and become more real if we find out that it is "motion" a quality or property of every physical existing thing?.

      I am sending you a practical summary, so you can easy decide if you read or not my essay "The deep nature of reality".

      I am convince you would be interested in reading it. ( most people don't understand it, and is not just because of my bad English). Hawking, "A brief history of time" where he said , "Which is the nature of time?" yes he don't know what time is, and also continue saying............Some day this answer could seem to us "obvious", as much than that the earth rotate around the sun....." In fact the answer is "obvious", but how he could say that, if he didn't know what's time? In fact he is predicting that is going to be an answer, and that this one will be "obvious", I think that with this adjective, he is implying: simple and easy to understand. Maybe he felt it and couldn't explain it with words. We have anthropologic proves that man measure "time" since more than 30.000 years ago, much, much later came science, mathematics and physics that learn to measure "time" from primitive men, adopted the idea and the systems of measurement, but also acquired the incognita of the experimental "time" meaning. Out of common use physics is the science that needs and use more the measurement of what everybody calls "time" and the discipline came to believe it as their own. I always said that to understand the "time" experimental meaning there is not need to know mathematics or physics, as the "time" creators and users didn't. Instead of my opinion I would give Einstein's "Ideas and Opinions" pg. 354 "Space, time, and event, are free creations of human intelligence, tools of thought" he use to call them pre-scientific concepts from which mankind forgot its meanings, he never wrote a whole page about "time" he also use to evade the use of the word, in general relativity when he refer how gravitational force and speed affect "time", he does not use the word "time" instead he would say, speed and gravitational force slows clock movement or "motion", instead of saying that slows "time". FQXi member Andreas Albrecht said that. When asked the question, "What is time?", Einstein gave a pragmatic response: "Time," he said, "is what clocks measure and nothing more." He knew that "time" was a man creation, but he didn't know what man is measuring with the clock.

      I insist, that for "measuring motion" we should always and only use a unique: "constant" or "uniform" "motion" to measure "no constant motions" "which integrates and form part of every change and transformation in every physical thing. Why? because is the only kind of "motion" whose characteristics allow it, to be divided in equal parts as Egyptians and Sumerians did it, giving born to "motion fractions", which I call "motion units" as hours, minutes and seconds. "Motion" which is the real thing, was always hide behind time, and covert by its shadow, it was hide in front everybody eyes, during at least two millenniums at hand of almost everybody. Which is the difference in physics between using the so-called time or using "motion"?, time just has been used to measure the "duration" of different phenomena, why only for that? Because it was impossible for physicists to relate a mysterious time with the rest of the physical elements of known characteristics, without knowing what time is and which its physical characteristics were. On the other hand "motion" is not something mysterious, it is a quality or physical property of all things, and can be related with all of them, this is a huge difference especially for theoretical physics I believe. I as a physician with this find I was able to do quite a few things. I imagine a physicist with this can make marvelous things.

      With my best whishes

      Héctor

        Hi Philip,

        What I understand when you say the projective or conformal symmetries are not "large" enough is that they could not be dimensionally reducing in the way holography is.

        So let me make another suggestion for a "hidden symmetry"... how about a kind of "fractal invariance"?

        The idea is to postulate that space (and not just the contents) is self-similar. It would not necessarily have to be a regular fractal, like a Koch snowflake, but could be a brownian fractal (in the sense that Mandelbrot used the term) or even some kind of Julia set. Restriction to a fractal subset can be dimensionally reducing.

        In fact, if I remember correctly, the measurements of the fractal dimension of luminous matter in the cosmos is about 2, instead of 3. It is also worth noting the efficiency of the fractal compression algorithm on various kinds of data, and that the wavelet packet algorithm is surprisingly effective on natural spatial and temporal signals. Laurent Nottale has explored some of the consequences for microphysics of assuming fractal structure.

        Hugh

          A scale factor symmetry is included in conformal symmetry. I think the scale relativity is more about symmetry seen in cosmological structures rather than symmetry of the underlying physics but I am not an expert.

          When I say that the symmetry is huge I mean that the symmetry algebra has many dimensions. A scale invariance may sound like a big symmetry in some sense but it is only one dimension of symmetry. We need an infinite number of them.

          However, scale relativity and projective symmetry are important parts of it so it is good that you are looking at thst.

          Thanks for your comments. I am working my way through all the essays

          Dear Philip, Congratulations. I sincerely hope you win this contest. Apologies if this does not apply to you. I have read and rated your essay and about 50 others. If you have not read, or did not rate my essay The Cloud of Unknowing please consider doing so. With best wishes.

          Vladimir

            Thanks Vladamir, I read your essay some time ago. Good to see you in a strong position.

            Dear Philip,

            Quantization is only an abstraction of infinity in that process of abstraction is infinite for absoluteness. Information paradox indicates that the nature of information is continuum rather than discrete and thus the nature of matter seems to be as string-matter continuum rather than as particles, that is realistic rather than probabilistic with observational information.

            With best wishes

            Jayakar

              Dear Philip,

              I think time has come to rate our essays and I would like to know whether you have rated mine; I am thinking of giving a very high rating. Please inform in my thread and I am glad to know that you are leading the essay contest on account of your amazingly written essay.

              All the best in the contest,

              Sreenath

                Thanks for your comments. I have read your essay some time ago and will take another look. Sorry, I don't discuss ratings as it may look like collusion.

                Dear Philip -

                You say: 'The lesson to be taken from holography is that there is a huge hidden symmetry in physics that nobody has yet appreciated.' I agree completely, and I must say that it is interesting in this contest to see how disparate thinkers start from such different perspectives and draw near to a concept of the Cosmos that can, I sense, accommodate a grand synthesis of their views.

                Simply put, we're all questioning long the established parameters, as has occurred throughout history - and we're doing so for the same reason as always: so that we might interact with a field of reality that is more comprehensive (or consistent), and less paradoxical.

                Like you, I see space-time as emerging from uncertainty - only my paradigm defines certain borders between the states of particles that are projected upon the Cosmos as particles aggregate in large numbers. Consequently, the Cosmos is divided into Zones of dimensionality, as are the particles that constitute it.

                This is similar to the holographic interpretation of reality you expound so well, and I wonder if you might not find some use in my paradigm in this regard?

                I ask because I work within the broadest set of parameters: Unlike you, my focus is not on the mathematics of the Cosmos, but rather on the evolutionary aspect of both observer and Cosmos, and the effects of their continuous correlation. I submit that it is in this area that our key assumptions must be reconsidered: Is not the historical expansion of mathematics into the field of reality a phenomenon that must also precisely describe the evolution of the human mind within that field?

                And is not space-time emergent as a function of evolution, a process that produces our experienced correlation (or symmetry?) in the space-time Zone? If so, symmetry is harder to describe in the quantum world and in deep space - these being the Zones from which space-time and the evolving observer emerge, so that they cannot have the consistency found in space-time, and in the highly evolved mind.

                Since information, organism and cosmos emerge from one source and remain correlated (or we could not make sense of anything) my conclusion is that It and Bit are correlated.

                I was captivated by your combination of mathematical thoroughness, and your concern for the 'real-world' aspect of whatever paradigm will one day resolve the issues at hand. Given this broad perspective, I'm sure you'll find many points of interest in my essay.

                Congratulations on this important work; I have rated it highly, and I look forward to your response.

                All the best,

                John.