• [deleted]

I take QT to be universal for a very elementary reason, that we can take the Hilbert space to be arbitrarily large when describing a finite amount of data. If a small-dimensional Hilbert space doesn't work, we introduce something larger that can (as we perhaps most notably do when we introduce QFT).

What is then difficult is to decide whether the simplest QT model is more or less parsimonious, natural in some pragmatic, human sense, tractable, or otherwise better or worse in whatever sense we think important on a given day than the simplest model we can construct in some equally universal theoretical landscape that might replace it (which, of course, we have to have in hand for us to be able to make a comparison).

This is an accommodation that I've thought through only to a limited extent, of which I would not make much claim, but I've decided to accept it as good enough so that I can work on other things without fussing at these particular shadows. Best wishes with your attempts to construct a more robust reason why QT is inevitable.

    It is very interesting to me when quantum theory is called odd by a quantum theorist.

    "Quantum theory is one of the most successful frameworks in science. But it is also decidedly odd. Physicists cannot use the theory to calculate the precise outcomes of quantum experiments before they have been performed, for instance; they can only work out the probabilities of getting a certain result."

    That statement naturally means that there is another reality that is not odd and where there are deterministic futures for all objects. In other words, the author has built in an implicit strawman of gravity action as the normal, intuitive reality.

    So why not face the demon of gravity down from the start...gravity action is the nemesis, not the second law. The second law is great. It is all about states. I like states. The question is, can the second law incorporate incompatible gravity states and quantum states, especially if gravity states are degenerate with quantum states.

    Will your second law show us the way? By the way, I think that gravity action turns out to be more way more odd than quantum action...

    The obsession with probabilities is misguided. It stems from the total lack of knowledge and training in branches of physics outside the little box of "quantum foundations." The result is that when an actual progress is made in the so-called "quantum foundations", it is not understood, because those who have cornered the subject to their political and financial advantage are not capable of understanding it.

      Steve,

      Is it NOT 'odd'!? Even to Bell it's "unprofessionally vague and ambiguous" he continued; "Professional theoretical physicists ought to be able to do better." (beables.. p173) I think he was rightly concerned about the "intrinsic ambiguity in principle" and the "complacency" from familiarity with the ancient myths some now believe is all there can be. Joy is then correct.

      The 'Problem of Interpretation of QM' has been encircled. And the solution, invisible from the front, may be seen from the back. ..The nonlinear Schrodinger equation seems to me to be the best hope for a precisely formulated theory.

      The shocking thing to many may be that the paragraph above is also a direct quote from John Bell (p.194)where he also directs us to fermion number density! I found he was exactly right and demonstrated that a classical geometric derivation of so the called "probability distribution" is possible in my essay;

      fqxi 2014; Do Bob and Alice have a future?.

      Bohr ignored Galileo; "He who undertakes to deal with questions of natural sciences without the help of geometry is attempting the infeasible.

      In '..unspeakable (p170) Bell described the current implicit acceptance of the bare 'probability' interpretation as; "sleepwalking". and lest those who believe otherwise about Bells views have any doubt;

      "The founding fathers of quantum theory decided even that no concepts could possibly be found which could emit direct description of the quantum world. So the theory which they established aimed only to describe systematically the response of the apparatus. ...in my opinion the founding fathers were in fact wrong on this point. The quantum phenomena do not exclude a uniform description of micro and macro worlds...systems and apparatus."

      So it seems we shouldn't be as terrified as some seem to be of finding that completed understanding. The common fear of having long held beliefs shown to require updating is selfish and invalid as an objection. Are perhaps complacency and arrogance not the main enemies of truth. It's well known in astrophysics that theory, like the universe, is in a state of continuous (relative) motions. The implications of the falsifiable and experimentally supported model in my essay are all positive, enlightening and unifying.

      The full mathematics describing the complete 'two part' state transformation has also now been published, from Prof Soiguine this week and flagged up on my essay blog courtesy of Luca Valeri. Thank you kindly Luca. As I suggested; the 3D dynamic variables can't be validly combined into a single operator as assumed in the conventional maths, inc. CSHS etc.

      Jon and Matt please do carefully review and comment.

      Thank you. Best wishes

      Peter

        • [deleted]

        Joy, I think 'little box' is an apt metaphor. Probability is without a doubt the least understood branch of mathematics -- and even less understood when applied to physical phenomena.

        One has to be reminded that to calculate probability, what one puts into the box determines what one gets out of it. When actual physical results turn up more than the box can hold, one is compelled to assume that one created something (entanglement) that wasn't in the box before one made a measurement (nonlocality).

        Take the calculation of the constant Pi by the Monte Carlo method:

        It is only because we know that the value of Pi exists before we describe the statistics by which Pi is a solution to the condition we have set (pi = 4M/N) for a circle we have prescribed, that the method generates to any arbitrary accuracy the value we know to exist as the exact solution to the equation.

        When we do the same thing with Bell-Aspect results, we are only getting confirmation of our assumption of entanglement and nonlocality. We specified the conditions and we got the solution we asked for.

        Problem is that the universe doesn't live in a little box. There's no 'pi in the sky' as John Barrow put it. We can't impose our mind's conditions on nature's structure and say we have 'found' something that wasn't there.

        (By the way, Peter, the foregoing illustrates exactly why your program doesn't work.)

        Peter M, if a 'robust' reason for the belief that (conventional) quantum theory is 'inevitable' turns out to be an infinite dimension Hilbert space, it predicts its own death -- because then the problem will have reverted to an analytical solution.

        We can just as easily (actually more easily) assume the analytical solution in the first place. Especially since we have more physical reason to do so -- and more especially since we now have the tools to prescribe extradimensional limits to the physical space. We just need a convincing way to test them.

        It seems erroneous to me, to look for the n-dimension finite Hilbert space solution which, if it exists, is compelled to assume that quantum theory will never be complete -- with the implication that our understanding of the universe will never completely map to how the universe actually works.

        The article avers, "Any theory worthy of replacing quantum mechanics would still need to assign probabilities to the outcome of experiments and so would be found in the landscape of generalised probability theories that Barrett and Leifer are investigating. Physicists should be able to instantly rule out a sub-section of the choices that violate the Second Law, due to their prediction that smashed mugs of coffee can surreptitiously reform."

        Generalized probability theories, as I know Leifer to support from earlier writings, are based in Bayesian probability interpretations, which means that some measure of personal belief unavoidably begs the question of entanglement; the circular argument doesn't even provide a sound strategy toward an objective basis for a foundational quantum theory.

        In fact, there do exist alternative frameworks, such as complex systems science that retain the second law of thermodynamics at multiple scales; i.e., the variety of thermodynamic paths toward equilibrium ensure unitary results with probability 1.0.

        Hi Peter, hope you remember me, I checked my emails and it was *only* 4 years ago when we last spoke. I finally did it, I have a proof of the necessity of QM and I am in the process of getting feedback on the draft for the archive. Hope to be able to upload it in about a month. I am extra cautious because this is a really big deal and I am triple checking everything.

        Your argument: "I take QT to be universal for a very elementary reason, that we can take the Hilbert space to be arbitrarily large when describing a finite amount of data." does not work because classical mechanics can also be put in Hilbert space formalism (http://en.wikipedia.org/wiki/Koopman%E2%80%93von_Neumann_classical_mechanics) and therefore the argument does not distinguish between classical and quantum mechanics.

        Best,

        Florin

        Clausius' famous principle "Entropy always increases" (which, according to A. Eddington, holds "the supreme position among the laws of Nature") was deduced in 1865 in the way presented by Jos Uffink on p. 37 in:

        Jos Uffink, Bluff your Way in the Second Law of Thermodynamics, p. 37: "Hence we obtain: THE ENTROPY PRINCIPLE (Clausius' version) For every nicht umkehrbar [irreversible] process in an adiabatically isolated system which begins and ends in an equilibrium state, the entropy of the final state is greater than or equal to that of the initial state. For every umkehrbar [reversible] process in an adiabatical system, the entropy of the final state is equal to that of the initial state."

        Clausius' deduction was based on three postulates:

        Postulate 1: The entropy is a state function.

        Postulate 2: Clausius' inequality (formula 10 on p. 33 in Uffink's paper) is correct.

        Postulate 3: Any irreversible process can be closed by a reversible process to become a cycle.

        All the three postulates remain unproven even nowadays; Postulate 3 is almost obviously false:

        Jos Uffink, p.39: "A more important objection, it seems to me, is that Clausius bases his conclusion that the entropy increases in a nicht umkehrbar [irreversible] process on the assumption that such a process can be closed by an umkehrbar [reversible] process to become a cycle. This is essential for the definition of the entropy difference between the initial and final states. But the assumption is far from obvious for a system more complex than an ideal gas, or for states far from equilibrium, or for processes other than the simple exchange of heat and work. Thus, the generalisation to all transformations occurring in Nature is somewhat rash."

        Pentcho Valev

        As far as I'm concerned, you guys are mired in nonsense.

        Firstly, I assert that there is no platonic realm; there is only this physical universe. So, what is the physical reality behind the numbers and complex numbers that seem to be necessary to explain reality? Numbers are symbols that represent something about physical reality; otherwise you must posit that they are entities that exist in their own right. Get the basics right first.

        Secondly, you all have an unwarranted BELIEF, nothing but a BELIEF, that reality is necessarily 100% deterministic. It is not quantum theory that is odd; what is REALLY ODD is the mob mentality with its very tame, but unshakable, belief that the underlying reality will be found to be 100% deterministic.

          " ... unshakable, belief that the underlying reality will be found to be 100% deterministic."

          And your belief that reality is probabilistic is objectively based on ... ?

            Quantum entanglement gives psychics and the paranormal something to work with. Grey aliens and UFO's could be some dark matter life form popping in for a visit. Ghosts and spirits could be some kind of quantum entanglement form of life. And with the millions and millions of people who have experienced these things, they make the whole subject matter respectable.

            Now let me give you some examples of woo. Time travel. The MWI interpretation of quantum mechanics. Those things are so in conflict with what we know about physics, conservation of energy, causality, etc., that they are not only impossible, but they are not observed by anyone.

              Lorraine,

              The underlying reality *IS* found to be 100% deterministic. It is only by politically suppressing the evidence presented that the physics community is able to maintain the façade of inevitable indeterminism (cf. Tom's rhetorical question below).

              It was the Higgs field that toppled materialism as a philosophy that describes nature; basically, the idea that particles are just hard spheres is dead. If nature allows invisible fields to exist, like the Higgs field, and nature also allows invisible matter to exist, than it is clear that the laws of physics do not oppose the existence of ghosts. In contrast, time travel is going to create paradoxes which make it impossible.

              If you treat a ghost like a quantum field, than it fits in very nicely with quantum mechanics. It goes a long way in explaining why so many people have had experiences with ghosts, shadow figures and other disembodied entities. Lot of people have seen the glowing red eyes of otherworldly entities. There is physical evidence of attacks by ghosts, which include scratching, biting, shoving. There are tons of poltergeist events.

              Skeptics are free to disbelieve. But in my view, it makes more sense. If the nature of reality is made of particles and fields, then it suggests that life forms should be able to exist as fields as well as particles.

              • [deleted]

              I never said "reality is probabilistic". Seemingly you must consider that there are only 2 possible options for the nature of reality: probabilistic or 100% deterministic.

              I might as well ask you : "And your belief that reality is 100% deterministic is objectively based on" what experimental evidence?

              Do you have anything to say about, or any ideas about, what it is that NUMBERS represent about the nature of physical reality, or are you a platonist?

              Joy,

              where is the experimental evidence for your belief that all individual physical outcomes are 100% deterministic i.e. the time and space "parameters" for every individual particle outcome is predictable/calculable beforehand?

              Do you have anything to say about, or any ideas about, what it is that NUMBERS represent about the nature of physical reality, or are you a platonist?

              Lorraine,

              I have to admit that as yet I cannot support my claim with unambiguous experimental evidence. All I have so far is extensive theoretical evidence (in 15 papers, a book, and numerous computer simulations) to support my deterministic framework. But I have also proposed an experiment to test this framework, which may someday prove me either right or at least partially wrong. If I am experimentally proven wrong about my framework, even partially, then I may reconsider my position about determinism (more precisely about Bell's no-go theorem).

              Concerning your question about numbers, to me they are simply excellent tools for us to do mathematics and physics. I rather not speculate anything deeper about numbers than that.