Hi Avtar,

On a quick scan, I'm afraid I can't find the connection between our essays, but I'll shoot you an email and see if we can cross paths this semester.

Cheers, Ken

Andrew,

It's great to see someone else pushing two-time boundary approaches to quantum problems... Section 2.1 definitely made me want to read more, and I hope to get to it soon. If you have any other drafts or preprints on this general topic, I'd love to take a look; please feel free to send them to me at whartonscience.sjsu.edu.

The continuous/discrete issue is an important one, and one on which I have fairly strong feelings, although that's outside the scope of this essay. (My entry in the previous contest is a pretty good summary.) But if you're looking for solitons, it sounds like you're aligned with me point of view that things are continuous at the most fundamental level... but it sounds like you want to treat these tiny solitons as discrete particles for all-practical-purposes?

But even if the structure of such a soliton appears to be less than 10^-19 m in high-energy collisions, would you agree that the structure of such a soliton passing through a double-slit interference experiment appears to be *much* bigger than that, on the order of the slit separation?

For the record, I do not see the electron as a soliton in the traditional sense as some tightly-bunched solution to some nonlinear differential equation. I think that it is best described by a field that corresponds to the classical Dirac Lagrangian Density, but doesn't necessarily solve any EOM, not even the Dirac equation. Such a field smoothly converges to a soliton-like bunch wherever such behavior maximizes its "relative volumes in the URT solution space" (to pick a quote from your 2.1 that meshes with my ideas fairly well). Such points are where we normally think that the "measurement" occurs, subject to caveats such as whether that measurement is erased in the future, as discussed in the previous contest entry. Inbetween measurements, one *wants* the electron-field to naturally spread out, or it becomes very difficult to describe interference in a "realistic" theory.

Welcome to the retrocausal club - I'll follow up on email soon!

Cheers,

Ken

Hi Harlan,

I don't much like the concept of "warm determinism"... I think (to paraphrase Jaynes) that's just scrambling together subjective and objective elements into a conceptual morass. If there's *any* part of the chain between measurements that's uncertain, why wouldn't you expect the whole length of the chain to be smoothly-uncertain? Why push all the uncertainty to the very end, at the moment when it makes the least physical sense?

As for your question, I'm not sure I can answer that without knowing what you mean by 'quantum universe'... There certainly shouldn't be two independent sets of physical theories, one applying to the microscopic world and one applying to the macroscopic. But I happen to think that the ultimate fundamental theory (which would govern both micro- and macro-) will in many ways look a lot more like classical Lagrangian field theory than standard quantum mechanics. We'll see... :-)

Hi George,

Thanks for the nice comments. I'm a bit of two-minds about the two-state formalism (:-) ... It's certainly a step in the right direction, with many elements that I like. But it's built so firmly on the standard QM foundation that it inherits too many of QM's traditional problems -- despite the fact that the retrocausal elements can in principle solve many of those same problems.

The biggest technical problem it inherits is the configuration-space of the standard quantum state. This isn't so evident in many of the papers as they usually only talk about single-particles, but if you delve into the details it only works if *both* the history- and the destiny-vector live in configuration space.

Now, these latest papers you mention are a step in the right direction, trying to fit entanglement experiments back into spacetime -- I was very pleased to see them when they were posted. But it's impossible to do this analysis in the traditional two-state formalism, because of the configuration-space problem. Basically they're pointing out what Huw Price and I have been arguing all along -- that the retrocausal elements can bring configuration space back to spacetime. But, by its very nature, the two-state formalism is not the right framework to accomplish this -- one needs something that departs from standard QM more radically.

I like the "adaptive selection" phrase, and might even use it as an easier-to-understand 3+1D description for the 4D physics I'm proposing. I'll be looking forward to reading both that preprint and your essay, which appears to be getting some very favorable feedback.

Cheers,

Ken

Hi Michael,

> Title not withstanding, you are not really arguing against the universe as literally a computer a la Lloyd or Wolfram. You only indirectly argue against them by positing a block universe, which certainly can't be computed.

I'm not sure I'm reading that correctly; surely you're not saying that there are no block universes that can be computed? Wolframs universes are block universes, and can be computed. Newtonian clockwork universes are also in that category. But as I said above, the block-universe has little or nothing to do with any of this.

>Now, you admit in your reply to me that you don't have a novel argument for block universe, though I assume you want that to be a distinguishing feature of LSU.

No, please don't assume that. Again, re-read my first response; physics is *all* block-universes, NSU, LSU, the lot. I don't need to argue for it, because it's not a distinguishing feature.

> In other words, there can be block worlds without local time-symmetric processes and there are time-symmetric accounts of QM that are not block world.

Yes on the first, no on the second (at least, any such account would also have a corresponding block-world account). At least, no one has ever come up with such a physical theory. (One would need two time dimensions, at which point time-symmetry would mean something quite different.)

> since we already knew that a time-symmetric psi-epistemic account of the QM could deflate the MP and provide a local picture of entanglement, that can't be your novel conclusion.

Maybe you know this, but this is still heresy in much of the foundations community. Regardless, I was more trying to answer the essay question than provide a 'novel conclusion'. The question is what flawed assumption we might be making without realizing it, and the answer is the assumption that the universe operates according to the Newtonian Schema. You may be one of the few people who have already internalized this point, but even many people in the retrocausal-quantum-camp still lapse into NSU-style thinking with alarming regularity. And people not in the camp are repelled from it, I think, because they think NSU is the only way to do physics.

> here's my challenge to you. If the lagrangian density L is a function of the field f and its derivatives, S is stationary wrt to f (LS formalism), and f satisfies the boundary conditions (LS formalism), then L satisfies a differential eqn (NS formalism). If you want your LS soln to allow for a continuously mediated (3+1)D story, then I don't see how L won't be a function of f and its derivatives, thus allowing for an NS counterpart. Can you explain how you plan to avoid this LS-NS correspondence?

The mistake is that you are assuming S has to be stationary with respect to small variations of f. True, this is how one gets classical field equations in classical physics, but it's simply not true when you look at the full quantum path integral (unless you take the hbar->0 limit, which is not physical.) Without that assumption, one cannot derive any equations of motion at all, and there simply is no NS version of a generic LS approach where the action isn't extremized. (We can debate whether the standard path integral still maps to the Schrodinger equation, but this is again beside the point, because LS is a broad framework that subsumes more than just the standard path integral; there will be other ways to use the action that lead to no general equations at all.)

I'm denying the existence of some master equation of motion that applies in all cases. No equations, no NS. It's that simple.

I'll tackle the RBW discussion back in email... but as I've told you, I'm not about to throw out all continuously-mediated LSU approaches until I have no other choice.

Cheers,

By the way I forgot to say that I totally agree with your critique of the idea of the universe as a computer. It's a totally overstretched analogy. And what is quite interesting is that if you analyse the flow of causality in computers, they are a classical case of top down action (I sketch this in my own essay). What drives them is the logic of the algorithms they employ - which are abstract entities.

Cheers

George

Dear Dr Wharton,

Your essay is clearly heading in the right direction. But, should this discussion stop at the physical aspect of the spacetime, which is still derived from a mathematical framework? Or have we missed the big picture precisely because of an even deeper bias we have about the spacetime at its most fundamental -- and physical -- level?

In my essay I introduce a model of the universe that resides entirely in ordinary spacetime. In this model, quantum spaces are explained as real but independent spaces, similar to the space of the universe.

However, something is less than ordinary: the hypothesis about the nature of this wrong assumption, which changes the way we see reality. Surprisingly, the hints about this wrong assumption were provided by Minkowski himself, but the scientific community ignored them for the last century.

Cheers,

Gene

    Ken,

    I agree a Lagrangian approach, indeed I've argued that the centre of a large mass such as a SMBH should not be a singlarity but a point of equilibrium. This is precisely a Lagrangian point, and gives a toroid form of gravitational potential, a form common to all em fields, tokamaks (fusion) and which I deal with every day as an astronomer, as AGN's etc.

    So of course maths (see my end note terms) but far more warily. Information theory shows your idea can be taken further (See McEachern essay) because the information possible in a mathematical abstraction is tiny compared to that contained in what it is trying to model (nature). I'm thus far more rigorous in applying the order; Correct concept first, Maths second. This requires the structures of logic, and a fully consistent ontological basis, which few of our theories posses. Expecting maths to accurately match reality is then foolish.

    My main point is that, if we drop the series of related and unproven assumptions identified, the gap between SR and QM disappears. SR is derived direct from QM, and consistent with GR. CSL, curved space-time etc are all natural and inevitable consequences and effects of a single and well evidenced (but poorly understood) series of real mechanistic quantum interactions. The picture is Einstein's Local Reality, with causality conserved and paradoxes resolved.

    The strict construction of truth propositional logic (hierarchical frames), and Dynamic Logic (interleaved but non interfering modes) are followed.

    The evidence is overwhelming, but the big issues with it are that it's;

    1. Entirely unfamiliar.

    2. So self apparent we can't possibly not already know it.

    3. Hiding so close in front of our eyes it forms a layer on our lenses.

    4. Far to 'big' and fundamentally important to be recognised or acceptable.

    5. Does not require complex mathematics to initially find, just visualisation of the evolution of kinetic effect (a new way of thinking).

    6. Although it agrees with the SR postulates, it finds a fault in one of the the assumptions used for SR so must of course be wrong.

    Could you see any of that? I'm considering reverting to the incremental approach (paper on resolving the Kantor interferometer issues accepted and due soon). Any other ideas?

    best wishes

    Peter

    • [deleted]

    Great essay, Ken. Had it been posted early enough, we would've made yours a prerequisite for ours and detailed how we satisfy your desideratum for an LS-only approach to new fundamental physics. Unfortunately, it wasn't in the blockworld cards so (with your permission) I'll have to do so here.

    If you're interested in new LSU-inspired approaches (LS formalisms) to fundamental physics which have been vetted and shown to have empirical consequence, read our essay. The LS approach outlined therein was inspired by our LSU interpretation of QM called Relational Blockworld (Foundations of Physics (2008, 2012,) and Studies in History and Philosophy of Modern Physics (2008)). In RBW, the manner by which we satisfy Ken's desire for an LS-only formalism (to the extent that it's possible, anyway) is to abandon dynamism altogether, i.e., get rid of (3+1)D time-evolved stories. The fundamental ingredients are relations, as advocated in Rickle's essay. In a sense, we're getting rid of the background/matter distinction in the spirit of Dreyer's essay. Among other things, this idea suggests correlations on a cosmological scale as Weinstein promotes in his essay. Such correlations suggest corrections to Regge calculus cosmology that we used to explain the Union2 supernova data without accelerating expansion or dark energy (Classical & Quantum Gravity (2012)) in direct opposition to the 2011 Physics Nobel Prize citation (Honorable Mention in Gravity Research Foundation 2012 Awards for Essays on Gravitation, http://users.etown.edu/s/STUCKEYM/GRFessay2012.pdf).

    Thanks for letting me use your essay to connect with others in the competition, Ken. Good luck!

      Ken

      Beautiful essay, and a very good point to get across. I hope you can get to read my own, and commend you to the other I refer therein, and particularly the Jackson and McEachern essays, the first for the mechanisms, both that and the second with some extended proof of your appraoch.

      Interesting times!

      Well done.

      Rich

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        Ken,

        I've been trying to put my finger on what strikes me as inconsistency in your desiderata. Perhaps you can help me understand where I'm missing the boat.

        Desiderata: An LS formalism that does not admit an NS formalism but does admit a (3+1)D continuously mediated story between Source and sink that explains the measurement outcome.

        My confusion: The way one obtains NS from LS is to demand the extremum condition of LS be satisfied instant by instant. This leads to the local as well as global conservation of some property or characteristic of the fields involved; in classical physics it's energy and in quantum physics it's probability. Thus, in order to avoid an NS characterization of your ultimate LS formalism, there can be nothing conserved instant by instant. But, if no field property or characteristic -- absolutely *nothing* -- is locally conserved, what *is* being mediated in a (3+1)D continuous fashion?

        I can imagine a field filling spacetime between initial and final hypersurfaces (and therefore between the worldtubes of the equipment). This field has some 4D global property that satisfies an LS constraint, but this field does not possess any property or characteristic that satisfies any constraint instant by instant (for any foliation). Trying to mathematically model such a field strikes me as a perfectly reasonable thing to do (it's what we're doing graphically). But, the very field property that rules out the possibility for an NS formalism also rules out the possibility of a (3+1)D story. At least, that's the way it strikes me. Perhaps you can dispel my confusion :-)

          • [deleted]

          Dear Prof. Wharton,

          I very much enjoyed the essay and realize you are looking at this from primarily a mathematical perspective as it relates to the physics more so than from the philosophical bend. Never the less once the Lagrangian perspective is taken it's hard not to wonder about what it all means as opposed to simply what observable results it has mandated. That is while metaphorically you say the universe is not a computer, yet stop there as not to share with us how you actually would have it imagined.

          As for instance I recall reading one of the first criticisms of such a perspective written by one of Fermat's contemporaries, Claude Clerselier, in him saying "Fermat's principle can not be the cause, for otherwise we would be attributing knowledge to nature: and here, by nature, we understand only that order and lawfulness in the world, such as it is, which acts without foreknowledge, without choice, but by a necessary determination". So although the LSU is certainly not a computer it presents as universe mandated to follow a central rule where the nature of the outcome is predecided. The deeper question for me then is to ask how a universe underpinned by predecision can have physical outcomes present as being so seemingly lawless respective to their certainty. That's not that I think we might ever be able to have such a question answered simply I find it as one interesting to think about.

          "Our intuition, going back forever, is that to move, say, a rock, one has to touch that rock, or touch a stick that touches the rock, or give an order that travels via vibrations through the air to the ear of a man with a stick that can then push the rock-or some such sequence. This intuition, more generally, is that things can only directly affect other things that are right next to them. If A affects B without being right next to it, then the effect in question must be indirect-the effect in question must be something that gets transmitted by means of a chain of events in which each event brings about the next one directly, in a manner that smoothly spans the distance from A to B. . . . We term this intuition 'locality.'

          Quantum mechanics has upended many an intuition, but none deeper than this one. And this particular upending carries with it a threat, as yet unresolved, to special relativity-a foundation stone of our 21st-century physics."

          -Albert, D.Z. & Galchen, R., 2009. "A quantum threat to special relativity", Scientific American, 300, 32-39.

          Kind regards,

          Phil

            • [deleted]

            Dr Wharton

            I would like reminding you my last essay

            http://www.fqxi.org/community/forum/topic/946

            I don't know -- I'm quite suspicious of attempts to 'start with logic', as that's exactly how anthropocentric mistakes are most likely to sneak into the foundations in the first place. This goes doubly so for efforts built on information theory.

            Now, I am a big fan of Einstein's method of building theories from big-idea principles, but at the end of the day it's the comparison of the math with reality that is the only way to determine if those ideas were right in the first place.

            And I'm afraid I disagree with your sentiments concerning a derivation of SR from QM in an ordinary causal (NSU) framework. Your essay dismisses Bell's theorem far too cavalierly for my liking. If you really want to tackle Bell inequality violations in a spacetime framework, check out my essay references [6] and [12] to see how an LSU can do the trick.

            Gene,

            There certainly may be other anthropocentric biases built into physics, and it also is true that I only experience this one universe, so that might unfairly bias me against your ideas.

            That said, as a physicist, I want to explain the particular universe that I observe. Maybe it will turn out that the best explanation will require the use of other places and times outside "my universe", but I can't see myself seriously pursuing that possibility until I've ruled out some simpler options.

            Here's a quote I still kind of like from my entry to FQXi's very first contest:

            "Looking to quantum theory for answers about spacetime is like looking to a roadmap for answers about geology: it's a tool designed for something else entirely. In general, quantum theory tells us nothing about spacetime except what its formulators put into it in the first place."

            Best, Ken

            Hi Mark,

            Yes, you and Silberstein are further along than any other LSU-style approach that I know of, and it's great to see some new cosmological results coming out of it. For now I hope we can agree to disagree about the continuum/discrete issue, and keep finding points of contact, such as this essay. More to come...

            Rich,

            Thanks for the kind words -- although I think both you and Jackson may be misreading my main point to some extent. From what I can tell about your essay (and Jackson's, and McEachern's), you're still working in a conceptual framework aligned with the NSU. If there's some LSU approach buried in any of those essays, I must have missed it, but I'm certainly interested in any such efforts.

            Best, Ken

            Hi Mark,

            I'm not sure if by "story" you mean "explanation" or mere "description"... If the former, we're not on the same page: LSU explanations don't make much sense when viewed sequentially in 3+1D -- they require 4D "stories". But I'll assume you're merely using "story" to refer to my hoped-for-3+1D representation of what is happening between measurements.

            As for whether giving up NS for LS means that *nothing* can be conserved instant-by-instant... That seems way too strong a conclusion. After all, there are aspects of Noether's theorems that provide conservation-type-rules (from the symmetries of the Lagrangian) even if the Euler-Lagrange equations are not strictly adhered to. There's a nice paper by Harvey Brown to this effect...

            If you ask me about ontology, "what is being mediated", my best guess right now is the classical Lagrangian density itself, and the classical fields that comprise it. (Bearing in mind that those fields need not strictly adhere to the Euler-Lagrange equations, just as single-photon experiments obviously don't adhere to Maxwell's equations.)

            On your last point, perhaps the problem is what you mean by "story" (see first paragraph above). Otherwise, I think we're on the same page. Also, note that LS approaches can give meaning to *new* instant-by-instant constraints, that don't make any sense in an NS framework -- such as enforcing a zero total Lagrangian density throughout spacetime (to pick a not-so-offhand example... :-).

            Cheers, Ken

            Phil,

            Yes, lots of great philosophical questions at the heart of this stuff. Usually I just point people to Huw Price at this point, but I'll venture a few comments of my own.

            Very nice quote about Fermat's principle, but if you'll look closely, the claim that "nature... acts without foreknowledge" is precisely the NSU assumption that the universe is just as limited as us humans.

            When you get into words like "predecided", I'll direct you to my discussions concerning the block universe in response to Silberstein, above. The very word "predecided" refers to two different times (its subject and object), and therefore has no physics translation -- the philosophical concept of predecision doesn't make sense in the block universe of modern physics.

            As for your excellent question: "The deeper question for me then is to ask how a universe underpinned by predecision can have physical outcomes present as being so seemingly lawless respective to their certainty." I certainly have a few thoughts. At one level, the hidden variables that I'm proposing (and that are necessary in any LSU) answers this to a large extent. Just because it's a block universe doesn't mean that we *know* the block; to the extent it's unknown, it appears probabilistic.

            But I've only recently come to realize this isn't the whole story. You can't get all quantum phenomena simply by constraining deterministic fields at two times. And the path I'm going down right now -- departing from deterministic equations of motion, underconstraining the intermediate physics between the LSU constraints -- provides plenty of uncertainty all around. (Although one must also relax the Principle of Sufficient Reason to the point where our universe is just one of many possible solutions to the same ultimate constraints.)

            As for that great quote you ended with, you may be surprised to see that we used that very quote to start Ref. [12]. We like the intuition of locality (as defined in that quote), and the LSU allows us to keep it, quantum phenomena notwithstanding.

            Best, Ken