The Universe Is Not a Computer by Ken Wharton

Ken

I like your paper, and think that this issue of the universe being or not being a computer is important. I don't think there is any conflict if we say that evolution of the wave function is deterministic. So its not so much that there are future boundary conditions, its that we can know some probabilities with certainty. We know that we are mortal for instance. We can not escape the unbearable certainty of some outcomes. There are certain two state systems.

Determinism is a tricky thing. There are two types that I can articulate, one is cold determinism of the classical, and the other is the warm determinism of the quantum. Determinism is a foundation it seems, but the universe seems to prefer the latter over the former.

In any case, it seems that you would agree with the statement that quantum universe is certainly more relevant than the classical one, would you agree?

Hi Ken,

First, regarding your essay. 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. So my questions were about trying to pin down your main conclusion. 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. Another possibility is that you are really arguing for a new time-symmetric interpretation of QM but again, merely being a block universe is neither necessary nor sufficient for that. 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. Yet another possible interpretation of your essay is that you see some necessary connection between LS and LSU or some ontological fact about reality, but of course any such inference would require extra premises not given in the essay. And finally, 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. I think the answer to what is novel in your essay comes at the end and again in your reply to me:

"In an LSU model, once you work backward to fill in the 4D spacetime, you can translate that 4D description to a 3+1D *description* of what is going on between measurements. But I do not think it will be "Newtonian", in that it will not always be a solution to some master differential equation, and I do not think it will be an "explanation", just a movie-like description of what actually happened. For an *explanation*, one will have to consider the whole 4D-LSU picture."

If you could find such a formalism, that might lend some extra credence to a block universe and could constitute a novel time-symmetric interpretation of QFT. If this is indeed the heart of your essay, 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? Isn't there a theorem to this effect? See http://en.wikipedia.org/wiki/Lagrangian for example.

Of course what's interesting about our account http://fqxi.org/community/forum/topic/1393 with the SCC at bottom, is that it's exactly what you are looking for except you would have to give up the continuously mediated (3+1)D description. Even though you say such a description wouldn't be explanatory, you think the lack of such a description entails instrumentalism. An understandable worry, but our view isn't instrumentalism. The key to understanding why is seeing that our "fields" are such that matter/sources and spacetime (the metric) are inextricably connected. So it isn't that some independent dynamical QM entity disappears at one point in some spacetime arena and re-appears at another point in that arena. Our "fields" are spacetimematter fields, not some continuous medium between events. Spacetimematter fields on the graph are the fundamental ontological elements and these are not dynamical entities in some (3+1)D sense, they are inherently 4D. In other words, for you "between" necessarily means "between time-evolved entities." To see what we're saying just flip that perspective, i.e., let "between" give rise to "time-evolved entities involved in processes." Then you'll be asking the right questions, e.g., "What is happening between measurements?" becomes "What is between for measurements?" [Answer: spacetimematter fields on a graph.]. When you take spacetimematter seriously, you have to re-think what you mean by "between", "duration", "distance" and so on, in such situations. This is as big a difference in what it means to "explain" as when we went from Aristotelian to Newtonian physics. You worry that our model is needlessly extreme, but that depends on the pay off right? Gauge fields on links allow us to discharge the mysteries of QM with a psi-epistemic account that explains interference, entanglement, discrete outcomes, all consistent with SR and no MP. It also allows us to explain so-called dark energy and unify GR and QFT. Nor do we give up spacetime as you accuse in your reply, we simply give up the differentiable manifold as fundamental. You are so close to us in spirit, if only you can throw off the remaining chains of dynamism.

Ken,

Thanks for the detailed response. You have provided me with several pieces of information I didn't know, and several other ideas I will have to carefully consider. I share your preference for GR and its few simple principles. However, coming from a math background and working mostly with very nice things like algebraic schemes and complex manifolds, it is hard for me to believe that the physical world is based on similarly nice things. I expect successful theories beyond GR and the SM to still be based on simple principles, but possibly involving arbitrarily messy mathematics. Take care,

Ben

Dear Ken

very nice thoughtful essay, one of the best. A comment: I am a little surprised you do not mention Aharanov's "two-time" formalism (see for example this paper and references therein), as it seems very close to what you are proposing as regards the way time works.

As regards the LSU formalism, this non-local approach is very interesting. You state "Instead of initial inputs (say, position and angle), Fermat's principle requires logical inputs that are both initial and final (the positions of X and Y). The initial angle is no longer an input, it's a logical output."

Yes indeed. What this approach does is very interesting: it puts dynamics into a framework that resembles the process of adaptive selection (the dynamics is offered a variety of choices, and selects one that it finds optimal according to some selection criterion, rejecting the others). This kind of process occurs in various contexts in physics, even though this is not widely recognised; for example it underlies both Maxwell's demon and state vector preparation (as discussed here ). I believe there may be a deep link to the dynamics you describe. This may be worth pursuing.

George Ellis

Hi Ken,

I'm very relieved that the Universe is not a computer! Sure, I need to re-read your essay many times to only partly understand it. But I need not know all the rules of hockey to see that a game is brilliantly played.

Best regards!

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

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

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 :-)

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