• [deleted]

I must confess that I wasn't thinking about a "Theory of Theories". My only thought at the time of the question was whether we would expect a quantum computer to produce results that include effects of gravity as an intrinsic output. For instance, if we were able to have sufficient precision, would a simulation of H2 using a quantum computer have gravity effects including into output even if the specific quantum algorithm was not designed to include those effects? It would seem that if we are to link spacetime to entanglement then we can not remove effects of QG without an appropriate correction (not sure if that is simular to the correction codes you are referring too).

Theory of Theories idea is interesting, and I would offer that one unifying concept in a theory of theories is that of ordering. Any non constant variable using any set of values that can correspond to numbers can be placed in some order. A cumulative sum of the values of the variables will always have some curvature (possibly none).

I think the idea of understanding vacua as programs is interesting. The notion that there is a code for the vacua is also interesting. I have to admit I didn't think about it along those lines until reading your article. I agree that a 200 byte program is not particularly complex, and certainly the set of meaningful programs can only be addressed by understanding the language or semantic problem associated with communication theory. To that end I can only offer the suggestion that its a question of the effectiveness of the information in the program. In that sense, we should think that there should be some language that maximizes the effect of the program in question, and it would seem that if we know that language, we could understand better what choices of programs are possible. In some sense we may need to look at approaches that maximize redundancy. I am not sure how far that treads into anthropic notions, where the observer in effect is somehow choosing the language and program that makes themselves possible, but again, we have to remember that the universe is what is ultimately observing itself, so it isn't really a question of human perception.

Just my thoughts.

  • [deleted]

I have to confess that I am no expert on these matters. I honestly have what might be called an introductory knowledge. To clarify things a bit the bounded quantum polynomial (BQP) algorithms a quantum computer can solve contain P-problems and BPQ is contained in NP, but probably not NP-complete = NP ∩ NP-hard.

I tend to think that P != NP. The reason is that an NP problem will run for a finite time, though it could be enormously large, and if P = NP it would seem to imply that there exists a P-Turing machine which could access the problem and determine the space/time bound of the problem in P. The only way I think this could be done is if there is an oracle input which feeds the solution to the P-TM.

The P = NP problem is important for physics, but it may not be crucial. The reason is that one can largely capture the important elements of physics in ways similar to coarse graining. Statistical mechanics involves a measure over Ω, S = log(Ω). The course graining invokes a "log" which washes out the intractable problem of computing every microstate.

Again I am rather inexperienced with algorithmic complexity theory. So these musings are at best proximal to the subject.

Cheers LC

  • [deleted]

Phil

Kilgore

When you reach the last Theory and the last smallest byte in the chain one can paraphrase the phrase

[en.wikipedia.org/wiki/The_medium_is_the_message_(phrase)]"the medium is the message"[/link] to read "nature is the theory". Does this help?

Oops sorry I sent a post with html tags by mistake and it was garbled.I meant to say:

Phil "...Theory of Theories"

Kilgore ".. the universe is what is ultimately observing itself, so it isn't really a question of human perception."

When you reach the last theory and the 'last' byte in the chain one can paraphrase McLuhan's phrase "the medium is the message" to read "nature is the theory". It has to be that simple.

    • [deleted]

    HIHI a Theory of Theories.you say dear scientists I have an idea,wait ..I know Let's name it"THE THEORY"

    Here is its real name ...THE THEORY OF SPHERIZATION A GUT OF SPINNING SPHERES....EUREKA also of course .

    FROM BELGIUM

    A simple gauge quantum spheres....cosmological spheres ....UNIVERSAL SPHERE.

    I make a little pub for my little theory of evolution.

    and of course a string is divisible,a sphere no!!!!

    Regards

    Steve

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    P in all likelihood does not equal NP. P=NP implies a universe radically different from the one we know. Aaronson has several excellent arguments, independent of mathematics, for the NP-hardness assumption. One is Darwinian. If P=NP why the hell didn't we evolve to take advantage of it? As things stand we're essentially ginned-up savanna apes staring around at the horizon hoping to see something we can maybe run fast enough to catch.

    I'll simply cut to what I see as the real chase, which is the physical description of the fundamental life process itself. That's physics too. It seems ridiculous to talk about decoding or retro-engineering the universe when we can't even algorithmize (physically model) protein folding. The reason we can't has entirely to do with what in computational complexity theory is called its location in NP. Another way of putting it is that our minds are what they are and that simply may not be good enough. But we do need to play games to stay sane, so laissez les bons temps rouler.

    • [deleted]

    It's an interesting thought that "decoding the universe" might be a NP-hard problem that we just can't solve. You might be right of course, but I would say two things.

    Firstly, assuming we just need to find the right vacuum of string theory, the size of the problem is 500 digits so it might be comparable to factoring a 500 digit number. We can factorise a 232 digit number now. Perhaps a better algorithm would take us up to 500 digits one day or quantum computer might be able to do it.

    Secondly it might not be a problem like that at all. It may be more like decoding the human genome which just required the right empirical data to make the process doable, even though the genome is described by a gigabyte of data. Decoding the universe may just be an experimental problem requiring knowledge of particle physics near or above the GUT scale.

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    Back in the late 1990s I read an article about ant colonies. The author pointed out how ants form pheromone trails which solve NP complete problems. The thing these guys have going for them is large numbers. In effect they form a huge statistical sample space of trails and the minimal paths are the ones which get used the most. The analogue to this is the planning of campuses that start out by letting people walk where they want and then later pave the beaten paths. In physics some theories have similar flavors, such as Maldacena's AdS~CFT which applies for "large N." In a funny sense while these are NP hard they are also complete problems so checking solutions is P. The application of large numbers, ants, people or quantum modes, gives the statistics which converge to the proper solution.

    Cheers LC

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    Hi Philip

    Very good essay offering quite convincing arguments for a speculative look at reality.

    I am wondering if there might be a possible compatibility between this idea of fundamental quantum information as you have described it and the proposal of David Bohm dating back to 1952 of "active information" which might exist as a sub-quantum field which would "inform" the QM wave function via what he calls the "quantum potential? It is an extension of DeBroglie's "pilot wave" theory and is starting to receive a bit more attention lately, mainly because it has the capacity to treat quantum theory in a physically real way, very naturally explaining what conventional quantum theory can't, EPR, wave function collapse etc. It also has the advantage of very simply removing notions like "superposition of states" (and therefore "collapse") via the non-local field.

    Do you see your fundamental qubits as generating only a geometry, ie spacetime/Calabi-Yau M, or as you seem to indicate in your section on the Holographic Principle, can it also apply to matter? If so, it could I think connect with Bohm in that the wave functions of elementary particles could be "formed" and "guided" by the information contained in the sub-quantum field of Qubit interactions.

    Just some ill-defined initial thoughts but I thought it might be interesting to relate the two concepts?

    Congatulations on your essay and good luck!

      Roy,

      Thanks for asking these questions. I'm also interested in the answers. FYI, my essay addresses some of these questions, and I would appreciate your thoughts.

      Also, I'd like to point out that Brian Whitworth's essay follows the logical implications farther than perhaps anyone else has done. I think both you and Phil would find his essay very interesting.

      Edwin Eugene Klingman

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      I like the idea that Bohm anticipated the holographic principle a couple of decades ahead of the quantum gravity version. His motivation for it was very different but since 't Hooft is interested in alternative quantum theories I am sure it must have had some influence on his thinking.

      I agree that other erssays such as Whitworth's and Klingman are interesting in regard to Bohm's work

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      Hello dear Sir,

      You are welcome.

      Sorry to say dear Basudeba.Here all people says the name as Peter, John,...

      You can say Steve you know I am 35 years old.

      Regards

      Steve

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      It is my understanding the difficulty with getting QFT to work with Bohm's interpretation of QM remains. Relativistic QFT of interacting fields describes the creation of particles with some mass gap, which Bohm's approach is not able to work with.

      Goldstein, I believe at Rutgers, has been trying to push this. I am not aware of his progress. However, at the end of it all Bohm's QM is still nonlocal, and the quantum potential has nonlocal properties. Bohm's QM has not managed to reduce nonlocal hidden variables to something which is local.

      Cheers LC

      Lawrence,

      You state: "Relativistic QFT of interacting fields describes the creation of particles with some mass gap, which Bohm's approach is not able to work with."

      A somewhat related question: A dozen years ago it was realized that the vacuum energy was off by 120 orders of magnitude. Do you believe that all relevant QED calculations (since 1947, or so) have been recomputed to take this into account? Have all 'virtual particle' assumptions been re-questioned? Only a year or so ago physicists were expecting a 'sea of strange particles' in the proton. It's not there. And 3 years ago the expectation of QCD was for a 'gas' when nuclei collide. They found a 'perfect fluid' as I predicted.

      Second, for about six months we've known that QED only comes within 4% of the proton radius in muonic hydrogen. Do you have an opinion as to the cause of this?

      Third, if, as I believe, the gravito-magnetic field is 10**31 orders of magnitude greater than Maxwell et al believed, then the relative changes between QED and GEM involve 151 orders of magnitude, in favor of GEM as a physically reasonable factor in the universe. Should this be ignored? At what point does one decide to look in new directions?

      Finally, my 'pilot wave' is not the same as Bohm's approach. He was not basing it on a very specific 'real' field, like gravito-magnetism, but on a more general 'quantum' field. So the fact that "Bohm's QM has not managed to reduce nonlocal hidden variables to something which is local" may not be entirely relevant to my approach.

      Thanks for your consideration.

      Edwin Eugene Klingman

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      We solve comparatively simple NP problems all the time. A sodoku or crossword or jigsaw puzzle are NP problems. Assisted by unquantifiable intuition, induction, creative insight you iterate your way to a solution which, when achieved, can be recognized almost instantly. Negotiating your way through a traffic jam is an NP problem. Sherlock Holmes was pretty adept at solving NP problems. But each case required him to start from scratch. These problems and their solutions are one-offs. You can't compress them algorithmically. You can come up with certain basic strategies which may work for subsequent problems, but strategies aren't solutions and sometimes they don't apply anyway.

      The basic genome isn't where it's entirely at nowadays, Craig Venter notwithstanding. The frontier is epigenomics, how specific genes interact in aggregate, often extremely complexly. In some senses the process appears to resemble multiple entanglement where the information is distributed among the quanta. What's junk DNA for, if anything? And so on. And where do these processes devolve from in the first place if they don't emerge from the fundamental physics of the universe? Wouldn't a valid fundamental theory need to comprehend them?

      Concerns like that.

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      A sodoku or crossword or jigsaw puzzle "is an NP problem" not "are NP problems" of course, sorry.

      • [deleted]

      I think the level of complexity in the world is some sort of extremal condition on paths in a Feynman path integral. Each path here corresponds to a particular "universe" or nucleation bubble. The vacuum configuration of each of these universes is determined by the compactification on a Calabi Yau space. Strings which wrap on these spaces have a duality with their mode index --- T duality. We are all of course familiar with path integrals and how very high frequency stuff or wild phases tend to cancel themselves out, so that you tend to get WKB behaviour or classical systems. My conjecture is that the huge degree or measure on the NP-completeness of the landscape (the extent of its space or need for qubits) is reflected in the complexity of the classical world. If so then of the 10^{500} or so landscape "realities" that exist there is a far smaller number of them which are classical. The "worlds" are those which satisfy an extermal condition on their complexity. This complexity is determined by the n-form flux through Dp-brane coincident with these wrappings.

      Cheers LC

        • [deleted]

        I accidently pasted my response to this in the bottom text box.

        LC

        Thanks, I can see how from this level of comprehension one would not worry about things like real physical anomalies, hundred order of magnitude errors, 4% accuracy of our best theories, or other such trivia.

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        I can't comment upon the muonic atom result which got the radius of the proton adjusted. I will offer my suggestion that the large muon has a small orbit and these results reflect the interaction of the muon with the proton. So the perturbation may be reflected by this result. To ferret out the problem requires some very complicated QED calculations with a quark or parton model of the proton.

        The fluid properties of the quark-gluon plasma is interpreted as an AdS_4 ~ QCD result. In effect the quark gluon has properties of a BTZ black hole in the anti de Sitter spacetime. There is then some parameter that depends on energy, so that at low energy the quark gluon plasma has properties of a black hole with very weak gravity, but as the energy is scaled up the QCD plasma becomes a real black hole with strong gravity. Nastase and others have written on this.

        The value of the cosmological constant means there is some field flux across the Dp-brane of the cosmology that counters the vacuum energy. The AdS has negative Gaussian curvature, which counters the Ricci curvature on the S^5. In the AdS_5xS^5 the boundary of AdS_5 = ∂AdS_5 ~ CFT_4. The AdS_5 has negative Gaussian curvature, which is from a 5-form which has a positive curvature on the S^5. On the boundary the gravitational curvature is zero. So problem involves the incidence of these curvature fluxes on the Dp-branes in the presence of these spaces.

        My understanding is that since Bohm QM does not involve Hilbert space, the whole thing lives in configuration space, it is difficult to model the production of particles. One can well enough derive a Bohm version of the Klein-Gordon equation, or the Dirac equation, and even the Maxwell equations. The problem comes when you couple them together. It is difficult to describe the generation of photons, which are massless, and from what I know up to now it is not possible to describe the pair production of particles with some mass --- such as e-e^ pairs.

        Cheers LC