Search FQXi


If you are aware of an interesting new academic paper (that has been published in a peer-reviewed journal or has appeared on the arXiv), a conference talk (at an official professional scientific meeting), an external blog post (by a professional scientist) or a news item (in the mainstream news media), which you think might make an interesting topic for an FQXi blog post, then please contact us at forums@fqxi.org with a link to the original source and a sentence about why you think that the work is worthy of discussion. Please note that we receive many such suggestions and while we endeavour to respond to them, we may not be able to reply to all suggestions.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

Contests Home

Current Essay Contest


Contest Partners: Fetzer Franklin Fund, and The Peter and Patricia Gruber Foundation

Previous Contests

Undecidability, Uncomputability, and Unpredictability Essay Contest
December 24, 2019 - April 24, 2020
Contest Partners: Fetzer Franklin Fund, and The Peter and Patricia Gruber Foundation
read/discusswinners

What Is “Fundamental”
October 28, 2017 to January 22, 2018
Sponsored by the Fetzer Franklin Fund and The Peter & Patricia Gruber Foundation
read/discusswinners

Wandering Towards a Goal
How can mindless mathematical laws give rise to aims and intention?
December 2, 2016 to March 3, 2017
Contest Partner: The Peter and Patricia Gruber Fund.
read/discusswinners

Trick or Truth: The Mysterious Connection Between Physics and Mathematics
Contest Partners: Nanotronics Imaging, The Peter and Patricia Gruber Foundation, and The John Templeton Foundation
Media Partner: Scientific American

read/discusswinners

How Should Humanity Steer the Future?
January 9, 2014 - August 31, 2014
Contest Partners: Jaan Tallinn, The Peter and Patricia Gruber Foundation, The John Templeton Foundation, and Scientific American
read/discusswinners

It From Bit or Bit From It
March 25 - June 28, 2013
Contest Partners: The Gruber Foundation, J. Templeton Foundation, and Scientific American
read/discusswinners

Questioning the Foundations
Which of Our Basic Physical Assumptions Are Wrong?
May 24 - August 31, 2012
Contest Partners: The Peter and Patricia Gruber Foundation, SubMeta, and Scientific American
read/discusswinners

Is Reality Digital or Analog?
November 2010 - February 2011
Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American
read/discusswinners

What's Ultimately Possible in Physics?
May - October 2009
Contest Partners: Astrid and Bruce McWilliams
read/discusswinners

The Nature of Time
August - December 2008
read/discusswinners

Forum Home
Introduction
Terms of Use

Order posts by:
 chronological order
 most recent first

Posts by the author are highlighted in orange; posts by FQXi Members are highlighted in blue.

By using the FQXi Forum, you acknowledge reading and agree to abide by the Terms of Use

 RSS feed | RSS help
RECENT POSTS IN THIS TOPIC

Jonathan Dickau: on 5/18/20 at 23:23pm UTC, wrote Hi Tim, I read your essay a while back and I have not seen any comment...

Torsten Asselmeyer-Maluga: on 5/18/20 at 21:17pm UTC, wrote Dear Tim, what a wonderful essay and it rings a bell. Now since 8 years I...

Tejinder Singh: on 5/18/20 at 0:41am UTC, wrote Thanks Tim! This connection between non-computable geometries and...

Tim Palmer: on 5/17/20 at 18:33pm UTC, wrote Dear Tejinder Connes comments in his book that non-commutative...

Tejinder Singh: on 5/17/20 at 18:01pm UTC, wrote Dear Tim, It was a pleasure reading your essay. and the valuable insights...

Tim Palmer: on 5/16/20 at 13:57pm UTC, wrote Dear Emily Thank you for your interesting and important questions. In...

Emily Adlam: on 5/16/20 at 13:09pm UTC, wrote This is a really exciting essay; I'm really intrigued by the connections...

Tim Palmer: on 5/16/20 at 13:04pm UTC, wrote James Personally, I have considerable difficulty with the concept of...


RECENT FORUM POSTS

Brian: "From the Nature abstract cited: "There is no theoretical reason to expect..." in Time to Think

Georgina Woodward: "Sorry, what a pigs ear I've made of that attempt to elucidate. Got muddled..." in Answering Mermin’s...

Stefan Weckbach: "John, "An electron is like a 2sphere, there is no cowlick, the hairs on..." in Answering Mermin’s...

Steve Dufourny: "Hi Jonathan, thanks for developing , I am understanding. I consider like..." in Towards the unification...

Jonathan Dickau: "It all fits together Steve... The optimal case for close-packing of..." in Towards the unification...

Steve Dufourny: "it is the meaning of my intuitive equation, E=m(c^2+Xl^2)+ Y with X a..." in The Effects of Inertial...

Steve Dufourny: "What I tell in resume is that for a good explaination of the..." in The Effects of Inertial...


RECENT ARTICLES
click titles to read articles

Time to Think
Philosopher Jenann Ismael invokes the thermodynamic arrow of time to explain how human intelligence emerged through culture.

Lockdown Lab Life
Grounded physicists are exploring the use of online and virtual-reality conferencing, and AI-controlled experiments, to maintain social distancing. Post-pandemic, these positive innovations could make science more accessible and environmentally-friendly.

Is Causality Fundamental?
Untangling how the human perception of cause-and-effect might arise from quantum physics, may help us understand the limits and the potential of AI.

Building Agency in the Biology Lab
Physicists are using optogenetics techniques to make a rudimentary agent, from cellular components, which can convert measurements into actions using light.

Think Quantum to Build Better AI
Investigating how quantum memory storage could aid machine learning and how quantum interactions with the environment may have played a role in evolution.


FQXi FORUM
October 29, 2020

CATEGORY: Undecidability, Uncomputability, and Unpredictability Essay Contest (2019-2020) [back]
TOPIC: Undecidability, Fractal Geometry and the Unity of Physics by Tim Palmer [refresh]
Bookmark and Share
Login or create account to post reply or comment.

Author Tim Palmer wrote on Jan. 25, 2020 @ 17:48 GMT
Essay Abstract

An uncomputable class of geometric model is described and used as part of a possible framework for drawing together the three great but largely disparate theories of 20th Century physics: general relativity, quantum theory and chaos theory. This class of model derives from the fractal invariant sets of certain nonlinear deterministic dynamical systems. It is shown why such subsets of state-space can be considered formally uncomputable, in the same sense that the Halting Problem is undecidable. In this framework, undecidability is only manifest in propositions about the physical consistency of putative hypothetical states. By contrast, physical processes occurring in space-time continue to be represented computably. This dichotomy provides a non-conspiratorial approach to the violation of Statistical Independence in the Bell Theorem, thereby pointing to a possible causal deterministic description of quantum physics.

Author Bio

Tim Palmer is a Royal Society (350th Anniversary) Research Professor in the Physics Department at the University of Oxford. Tim's PhD (under Dennis Sciama) provided the first quasi-local expression for gravitational energy-momentum in general relativity. Through most of his research career, Tim worked on the chaotic dynamics of the climate system and pioneered the development of ensemble methods for weather and climate prediction, for which he won the Institute of Physics's Dirac Gold Medal. However, Tim has retained an interest in foundations of physics and published a number of papers on non-computability in quantum physics (the first in 1995).

Download Essay PDF File
Note: This Essay PDF was replaced on 2020-04-17 07:52:00 UTC.

Bookmark and Share


David Brown wrote on Jan. 26, 2020 @ 01:54 GMT
From page 6, "In a local deterministic theory, each pair of entangled particles is described by a supplementary variable λ, often referred to as a hidden variable ... " — is this meant to be the definition of a "local deterministic theory" or is it a statement about the conventional wisdom of physicists concerning a "local deterministic theory"? Is it possible that time, space, energy, quantum...

view entire post


Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Jan. 27, 2020 @ 19:25 GMT
You can take it as a statement about conventional wisdom, allowing me to relate my uncomputable model to more conventional computable models.

Bookmark and Share


Dizhechko Boris Semyonovich wrote on Jan. 27, 2020 @ 16:55 GMT
Dear Tim Palmer, Your essay is the most verbose and most abstract of those that I have seen here. Fractals, attractor, Cantor set, p-adic numbers are very cool. To say a lot and to show your awareness of everything is a feature of scientific luminaries. I cannot compete with you with my neo-Cartesian generalization of modern physics, which is based on the identity of Descartes' space and matter and which claims that space moves because it is matter. Only in my essay I briefly show that the principle of uncertainty takes the opposite meaning, i.e. becomes the principle of definiteness of points of space, which is matter; further I show the relationship of the probability density of states with the Lorentz factor; I further explain the formula mass-energy of equivalence by the fact that for each corpuscle there is a flow of forces equal to the product of the Planck constant and the speed of light - ch (Casimir force); further I propose the definition of mass as a stream of centrifugal acceleration through a closed surface of a corpuscle, etc.

         I invite you to discuss my essay, in which I show the successes of the new Cartesian generalization of modern physics, based on the identity of space and matter of Descartes: “The transformation of uncertainty into certainty. The relationship of the Lorentz factor with the probability density of states. And more from a new Cartesian generalization of modern physics. by Dizhechko Boris Semyonovich. "

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Jan. 27, 2020 @ 19:26 GMT
Thank you. I look forward to reading your essay.

Bookmark and Share


Jochen Szangolies wrote on Jan. 28, 2020 @ 07:37 GMT
Dear Tim,

congratulations on an eminently readable and engaging essay on a difficult topic! I will need some time to fully digest your arguments, but I wanted to leave a few preliminary comments---also because our two approaches have some overlap, in particular as regards undecidability and Bell/EPR.

I'll state my biases upfront: I'm skeptical of any sort of 'completion' of quantum...

view entire post


Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Jan. 28, 2020 @ 08:03 GMT
Thanks indeed for these very kind remarks.

A few comments. I do not really view my approach as a completion of quantum mechanics in the sense of providing extra structure to be added to the quantum theoretic formalism. As mentioned in the Appendix to the essay, the closed Hilbert Space of quantum mechanics only arises in the singular limit where my finite fractal parameter p is set equal to infinity, and this is an unphysical limit! Hence, rather than complete quantum mechanics, my own view is that, guided by quantum theory, we have to go back to basics taking ideas based around non-computability and fractal geometry seriously!

You are right to be sceptical of superdeterminism. However, the reasons to be sceptical - e.g. that it would imply statistically inequivalent sub-ensembles of particle pairs in a Bell experiment, simply do not apply to this model. Instead, I focus on a violation of Statistical Independence which only has implications when considering hypothetical counterfactual measurements in a Bell experiment. This interpretation of the violation of SI only makes sense in the type of non-computable model proposed.

In fact this same point will also lead to a negation of the Pusey Barrett Rudolph theorem, through a violation of Preparation Independence. However, once again such a violation only occurs when considering counterfactual alternative preparations.

The bottom line here (something I focus on in the essay) is that we have to think very carefully about what we mean by things like free choice and causality in these quantum no-go theorems: counterfactual-based and space-time based definitions (c.f Newton clapping his hands in the quad) are inequivalent in the type of non-computable model I am proposing here.

Bookmark and Share

Joe A Nahhas replied on Jan. 29, 2020 @ 00:39 GMT
I can produce general relativity experimental numbers and special relativity experimental numbers 5000 times using any of 5000 physical sciences laws and using any level mathematics including 5th grade arithmetic and I can produce entire Einstein's relativity theory from Newton's equation contrary to what main stream scientists claim and I can produce it 5000 times as visual effects between (27.321 days, 365.256 days) motion (PHD dissertation subject 1990 University of Michigan Nuclear engineering department) I introduced "Hacking Physical Reality" and ended "Nobel Physics" decades ago. I know I sound unbelievable but it is a fact and is a well established fact.

Bookmark and Share
report post as inappropriate

Jochen Szangolies replied on Jan. 29, 2020 @ 16:57 GMT
I've been thinking about differences and similarities between our respective models. I focus on a function which assigns values for all measurements and all states of a certain system, and show that there must be measurements such that this function is undefined---which yields the backdrop for Bell inequality violations. This also needs a restriction on admissible counterfactuals---otherwise, the...

view entire post


Bookmark and Share
report post as inappropriate


Joe A Nahhas wrote on Jan. 29, 2020 @ 00:23 GMT
Physical reality can be hacked. First method of hacking physical reality is visual hacking. Visual hacking of physical reality is a display of physical objects motion in real time and physical objects motion has nowhere to hide caught naked for the first time since the beginning of time on display and in real time.

1 – Visual Hacking of Earth’s motion or a display of Earth’s motion in real time = 27.321 days cycle wrongly assigned to the Moon.

2 – Hacking the Sun’s motion or a display of the Sun’s motion in real time = 365.256 days cycle wrongly assigned to Earth.

3 – Physical sciences 5000 laws of physics, astronomy, physical chemistry, physical biology, physical engineering and technology in its entirety is based on light sources as a measuring tool and as used it only measures physics lab physical motion or Earth’s motion in 27.321 days.

4 – The (27.321 days, 365.256 days) Time cycles distance equivalence cycles = (R meters, C meters); R = Earth’s theoretical radius = 6371000 meters and C = 299792458 meter claimed as light speed/second

4 – The Space – Time errors = NASA’s space data sheets

5 – The Inverse Space – Time errors = CERN’s atomic/nuclear data

Meaning: Physical Sciences 5000 physics laws can be produced as (27.321days, 365.256 days, 6371000 meters, 299792458 meters) space –time errors is the subject of this contest of Extermination of Modern and Nobel Prize winners physics and physicists from 1610 Copernicus to 2020 Nobel winners using any level mathematics including 5th grade arithmetic and starting with Physics Most Erroneous Equation E = MC2. Are you ready to hack and strip the incontestable truth of physical reality?

Bookmark and Share
report post as inappropriate


Jonathan J. Dickau wrote on Jan. 30, 2020 @ 19:33 GMT
I very much like this idea Tim...

But I will have to re-read your paper a few times to fully grasp the depth of your reasoning. It seems reminiscent of some of the wild-sounding ideas about Cantorian space from Mohammed El Naschie when he was editing 'Chaos, Solitons, & Fractals' but with a different flavor. I think maybe your ideas have a more solid basis, but with El Naschie it is hard to tell - because so many of his references are self-citations from earlier work, hidden behind a pay wall.

I also talk about fractals in my essay, but the context is rather different. For what it is worth; I like the work of Nottale on Scale Relativity, and I admire the breadth of its explanatory power as a model, though I don't think he got every detail right. When sent a copy by the publisher of his book for review; I enthusiastically recommended its publication. And it inspired my departed colleague Ray Munroe, who I think used it in an FQXi essay.

More later,

Jonathan

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Jan. 31, 2020 @ 07:49 GMT
I think the mathematics in my talk is pretty solid. As to the physics, well at the end of the day it will come down to experiment. I expect the crucial experiment to test invariant set theory will lie in the field of table-top experiments which probe the accuracy of quantum theory in domains where the self gravitation of a quantum system is not negligible. For example, based on the idea that gravity represents a clustering of states on the invariant set, the theory predicts that gravity is inherently decoherent and cannot itself encode entanglement.

Bookmark and Share

Jonathan J. Dickau replied on Jan. 31, 2020 @ 15:30 GMT
I like that answer Tim...

There was recently published a paper describing an experiment that claimed to disprove objective reality, using a system with 6 entangled qubits. I think this is wrong. There are too many co-linear points, and the entire apparatus is co-planar. There are also 6 points instead of the 7 required by projective geometry. An experiment designed to correct these flaws could also search for the effects you describe. A ball of osmium placed at one end of the bench could be used to detect gravity-induced decoherence, and so on.

In other words; I think it could be done.

All the Best,

Jonathan

Bookmark and Share
report post as inappropriate

Jonathan J. Dickau replied on Jan. 31, 2020 @ 15:41 GMT
For what it's worth...

I had some interaction with Phil Pearle, when he was first developing statevector reduction theory, which later blossomed into CSL. I have followed that evolution somewhat. But I recall a recent paper by Ivan Agullo that also talked about gravity-induced decoherence and broken EM symmetry, which I will try to find.

I'd love to discuss this further. I will try to read your paper again first.

Best,

Jonathan

Bookmark and Share
report post as inappropriate


Robert H McEachern wrote on Feb. 1, 2020 @ 20:53 GMT
Tim,

On page 6 of your essay, you state that "The principal obstacle in drawing together chaos and quantum theory is therefore not the linearity of the Schrodinger equation, but the Bell Theorem."

You appear to be unaware of the fact that Bell's theorem only applies to entangled, perfectly identical particles, like identical twins. There is no evidence that such idealized particles actually exist in the real world. Consequently, it is easy to demonstrate that entangled, non-identical, "fraternal twin" particles, will reproduce the observed "Bell correlations", with supposedly impossible-to-obtain detection efficiencies, and without any need for hidden variables, non-locality or any other non-classical explanation. This has a direct bearing on your issue of "drawing together chaos and quantum theory", since the underlying cause for the "quantum" behaviors, turns out to be, one single-bit-of-information removed from chaos (unrepeatable behavior).

Rob McEachern

Bookmark and Share
report post as inappropriate


Lorraine Ford wrote on Feb. 5, 2020 @ 12:27 GMT
Tim Palmer,

You recently co-wrote an arxiv paper titled Rethinking Superdeterminism together with physicist Sabine Hossenfelder [1].

I happen to think it is rather strange for an internationally renowned meteorologist to think that the climate and everything else is superdetermined anyway. Here is an exchange I had today with your co-author Sabine Hossenfelder about whether the fires and the destruction in Australia are/were superdetermined [2]:

Lorraine Ford 1:31 AM, February 05, 2020

Re "your paper with Dr. H[ossenfelder]" (on superdeterminism): I hope Dr. H[ossenfelder] and Dr. P[almer] are enjoying the smell of burnt koala flesh and fur wafting over from Australia. It was all superdetermined, according to them.

Sabine Hossenfelder 2:34 AM, February 05, 2020

Lorraine, You think you are witty. You are wrong.

Lorraine Ford 3:16 AM, February 05, 2020

Sabine, I DON'T think I'm witty. I'm Australian, living with smoke-hazy skies, the horror of a billion animal deaths, let alone the people who have died, and more than 10 million acres of land burnt. You are saying that this was all superdetermined.

Sabine Hossenfelder 4:12 AM, February 05, 2020

Lorraine, Correct. If you have a point to make, then make it and stop wasting our time.

1. https://arxiv.org/abs/1912.06462v2

2. http://backreaction.blogspot.com/2020/02/guest-post-undecida
bility.html

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Feb. 5, 2020 @ 13:28 GMT
Lorraine

Perhaps the most important thing to say in relation to my essay is that there is a difference between "superdeterminism" and "determinism". The former questions whether it is the case that, in a hidden variable model of the Bell experiment, the distribution of hidden variables are independent of the measurement settings. Without bizarre conspiracies, such distributions certainly...

view entire post


Bookmark and Share

Lorraine Ford replied on Feb. 6, 2020 @ 00:43 GMT
Tim Palmer,

Thanks for your detailed reply. I think I WAS a little confused about the difference between determinism and superdeterminism: thanks for explaining. However, you are still in effect saying that every single koala death by fire was pre-determined.

I will put the determinism issue another way, in terms of the problem of decidability: how we make decisions, and how we...

view entire post


Bookmark and Share
report post as inappropriate

Author Tim Palmer replied on Feb. 6, 2020 @ 07:44 GMT
We are going a bit off topic here. However, as I discuss in my essay, one can view free will as an absence of constraints that would otherwise prevent one from doing what one wants to do, a definition that is compatible with determinism. From this one could form a theory of how we make decisions based on maximising some objective function which somehow encodes our desires. This does allow one to learn from previous bad decisions, since such previous experiences would provide us with data that a certain type of decision, if repeated, would lead to a reduction, not an increase, in that objective function.

However, we are veering into an area that has exercised philosophers for thousands of years and I suggest this is not the right place to discuss such matters. Of course, I respect your alternative point of view - there are many eminent philosophers and scientists who would agree with you.

Bookmark and Share


Domenico Oricchio wrote on Feb. 5, 2020 @ 17:46 GMT
I have a problem with the idea that the chaos is incompatible with relativistic invariance; I cant’t give an example now, but a differential equation that is relativistic invariant and chaotic could be possible: I am thinking that in the solution set of the Einstein Field Equation there could be a solution that covers the space with a non-integer dimension, thus obtaining chaos for the metric tensors dynamics. I think that, for example, the Black Hole merger has an attractor (fixed point or almost limit cycle).

An Einstein field equation with weak field is a linearizable theory, so that there is an approximation nearly linear.

I don’t understand: is a quantum non-locality the effect of the quantum field theory? The gauge boson interact between parts of the system, that transmit quantum information. So that to say that a system must satisfy bell's theorem is not equivalent to say: must a gauge boson exist?

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Feb. 6, 2020 @ 07:51 GMT
Actually what I say is that chaos is only superficially incompatible with relativistic invariance. The key is to "geometrise" chaos and that can be done by considering the invariant sets of chaos. I then try to show that these invariant sets may in turn help make chaos compatible with quantum theory.

My own view is that the resolution of the Bell Theorem is not through quantum field theory, since that is an extension of quantum theory. Rather my belief is that there is a deeper deterministic formalism based on non-computable fractal invariant sets which has quantum theory as a singular limit.

I am currently working on an extension of these invariant set ideas to incorporate the formalism of relativistic quantum field theory.

Bookmark and Share

Domenico Oricchio replied on Feb. 6, 2020 @ 14:43 GMT
Your essay is interesting.

Reading it made me think.

For example if there was a chaotic state in general relativity, then is it possible that Hausdorff's measure of particle trajectory an relativistic invariant? If it were not so, then there would be an observer for whom the relativist trajectory is non-fractal, but this seems unlikely to me (it's like a change of topology, to change from a chaotic trajectory to a non-chaotic trajectory).

Also for the Bell theorem (or the Einstein-Podolsky-Rosen paradox), it is possible to study the Feynmann diagram for the cross section in the scattering of two polarized Dirac particles (I read today the results in Greiner book) and to obtain the probability of the final state (with elicities). If there are interaction, so gauge bosons, then there is not an instantaneous effects; the collapse of Alice state communicate the state to Bob using the gauge bosons interaction, with the light speed.

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Feb. 6, 2020 @ 07:42 GMT
We are going a bit off topic here. However, as I discuss in my essay, one can view free will as an absence of constraints that would otherwise prevent one from doing what one wants to do, a definition that is compatible with determinism. From this one could form a theory of how we make decisions based on maximising some objective function which somehow encodes our desires. This does allow one to...

view entire post


Bookmark and Share


Colin Walker wrote on Feb. 6, 2020 @ 23:20 GMT
Hi Tim,

It is quite a revolutionary program you have embarked on, overthrowing the infinitesimal and subverting the continuum. Your standard of rationality includes its mathematical definition: that any rational quantity can be expressed as a ratio of whole numbers. The conviction that the infinite and the infinitesimal have no place in physics goes well with the idea that appropriate...

view entire post


Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Feb. 7, 2020 @ 08:15 GMT
Thanks Colin.

Bookmark and Share


Jonathan J. Dickau wrote on Feb. 13, 2020 @ 22:18 GMT
Hello again Tim,

After reading Lawrence Crowell's paper; I have a greater appreciation for your work, and even moreso that you are able to write so lucidly about it for lay audiences. I am impressed. I will have more questions now, after all that fuel for thought.

Would the correctness of your theory imply that the fabric of spacetime is fractal? This is a feature of several quantum gravity theories, in terms of the microstructure. Does that project onto the large scale structure of the cosmos in your view? Would it surprise you if I said it appears some of your starting assumptions would follow naturally, if my own theory pans out?

Tip of the old iceberg for you.

More later,

Jonathan

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Feb. 14, 2020 @ 07:32 GMT
Thanks for these kind comments Jonathan.

You ask a good question. However, to be honest, I am not 100% sure at present what my model implies about the structure of space-time, so I prefer to be agnostic about this for now. However, I am working on a generalisation of my model so that the properties of momentum/position commutators are (like spin commutators) describable by number theory. This will allow me to start reformulating relativistic quantum field theory in a more deterministic framework, and from there answers to your questions should emerge. However, I want to do this slowly and carefully, and not jump to conclusions that may at first sight seem reasonable, but will ultimately turn out to be wrong.

Bookmark and Share

Jonathan J. Dickau replied on Feb. 14, 2020 @ 15:52 GMT
That was a satisfying answer Tim...

This speaks to the question of what sort of evidence of your theory would we see in the cosmos that might provide verification or refutation for its veracity. I asked a similar question of Gerard 't Hooft at one point and his answer was similar - that it was too early to tell what the cosmic evidence would be.

The following year at FFP11; he elaborated in his talk about the desirability of and difficulties with obtaining Lorentz invariance in a CA based QG theory, but still no hard predictions about what we would observe (in black hole emissions perhaps) that would distinguish it from the standard.

I've seen or heard several predictions from Loop Quantum Gravity folks about possible signature detections - such as Lorentz invariance violations, comb filtered emissions from black holes, and so on. But I see that each time such a prediction is made, folks will jump on it as excluding a theory if the exact signature predicted is not found. And String Theory folks seemingly refrain from making any hard predictions at all.

All the Best,

Jonathan

Bookmark and Share
report post as inappropriate

Steve Dufourny replied on Mar. 5, 2020 @ 10:38 GMT
Hello to both of you,

the problem about these strings is that it is a kind of fashion now about what we have at this planck scale and about the 1D main Cosmic field creating our reality by the Waves, fields and oscillations. But in fact a sure thing is that nobody can prove and be certain about this philosophical generality. The same for ,my gravitational coded aether made of spheres sent from the central cosmological sphere. We cannot affirm and all rational deterministic searchers accept the difference between a proved law, equation, axiom or an assumption. Nobody can affirm what we have at this planck scale nor about the philosophy of the generality of this universe. Have we coded particles or Waves creating our geometries, topologies, matters and properties and this emergent space time. We know that inside the theoretical sciences Community, all we are persuaded and that the Vanity is important, but without proofs we cannot affirm, it is a fact.

What is really this space, this vacuum ? is it still this gravitational superfluid coded aether or fields different , we don t know simply and we must accept this and our limits in knowledges.

Regards

Bookmark and Share
report post as inappropriate


Jack James wrote on Feb. 17, 2020 @ 10:34 GMT
Dear Tim,

Great essay, congrats. Wish I had a background in physics to completely understand. Please indulge me if you have time.

1) Are you essentially suggesting that mathematical incomputability/undecidability exists as space-time, emergent from quantum non-linearity (as that is what the wave function seems to suggest, which may in effect be the cause of macroscopic gravity?

2) If something (anything that exists as part of detectable science) is incomplete as a matter of ontology (incomplete in the Godel sense) how could that ontology possibly verify determinism or superdeterminism?

Best,

Jack

(Essay: Misalignment Problem - You may enjoy the amalgamated sleuths section)

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Feb. 17, 2020 @ 12:49 GMT
Yes I do think that relativistic space-time will be found to be emergent from this fractal state-space geometry. However, making this a precise notion, and not just an aspiration, is something that I am currently thinking hard about!

I'm not sure I fully understand your second question. However, it triggers in my mind an important question: are there experimentally testable consequences of determinism? Again, this is something my collaborator Sabine Hossenfelder and I are currently thinking about.

So, in short, I can't answer either question, but they both touch on important issues!

Bookmark and Share

Jack James replied on Feb. 18, 2020 @ 01:27 GMT
Thanks Tim,

I am very glad you are thinking (with the great tools of physics) about the same questions I am.

Re Q2 I think you have grasped my question in your statement "are there experimentally testable consequences of determinism?" Because if Godel's incompleteness manifests physically (space-time & mass) then you could never test determinism because the physical system would have unknowable states that cannot be determined by the system itself. So you couldn't have a determinable system, could you?

Best,

Jack

Bookmark and Share
report post as inappropriate

Author Tim Palmer replied on Feb. 18, 2020 @ 08:04 GMT
My view (which I tried to express in the essay) is that such undecidability only manifests itself in questions about the structure of state space, not in questions about the structure of, or processes in, space-time. Hence I do think there are experimentally testable consequences of determinism.

Bookmark and Share


Yehonatan Knoll wrote on Feb. 20, 2020 @ 17:41 GMT
Tim,

What Bell had in mind (and explicitly expressed so in many interviews) is that, if particles are little machines, then his inequality must be respected. Now, as with any statement regarding the physical world, it tacitly assumes also `common sense'. One can bend this vague notion to an arbitrary extent, but there is a more direct attack on Bell's theorem, which has been staring us in the face for over a century: Particles (and chaotic systems and humans) are not machines! (no new-age stuff)

You are invited to read my essay which is further relevant to your main area of expertise - predicting the behavior of chaotic systems. Ensemble average over initial conditions is probably not the right way to do so.

Bookmark and Share
report post as inappropriate


Lawrence B. Crowell wrote on Feb. 22, 2020 @ 22:06 GMT
I finally got to reading your paper. I have been working to get a piece of instrumentation developed meant to go to another planet. In reading this I think what you say is maybe not that different from what I develop.

Your paper drives home the point on using the Blum, Shub, and Smale (BSS) concept of computability. This is an odd concept for it involves complete computation of the reals...

view entire post


Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Feb. 23, 2020 @ 08:29 GMT
Please take a look at the referenced paper by Simant Dube. He finds essentially the same computability result as Blum et al, studying the fractal attractors of iterated function systems.

Bookmark and Share


Eckard Blumschein wrote on Feb. 28, 2020 @ 11:45 GMT
Dear Tim Palmer,

If you are a physicist rather than an inflexible mathematician, you may hopefully be in position and ready to answer my question:

While I know, "a closed interval is an interval that includes all of its limit points", I guess there might be a fundamental point-based alternative to the "dot-based" mathematics from Dirichlet up to Heine and Borel. Given real numbers constitute Euclidean points, isn't then a discrimination between closed and bounded only justified for rational numbers? Isn't it logically impossible to include a single real number? Is the notion limit point really reasonable?

Well, this request relates to my own essay rather than directly to your essay. I am just curious.

Sincerely,

Eckard Blumschein

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Mar. 2, 2020 @ 10:51 GMT
All I can say is that these are deep questions!!

Bookmark and Share

Eckard Blumschein replied on Mar. 2, 2020 @ 13:42 GMT
Thank you.

I will try and explain at 3385 why I as a layman in mathematics feel forced to deal with fundamentals of mathematics.

Let me here quote from your abstract something easily understandable to everybody:

"...undecidability is only manifest in propositions about the physical consistency

of putative hypothetical states". In my words: Continue calculating as if.

Just an aside on your Hilbert quote after illustrating Cantor's dust: "The infinite is nowhere to be found." I argue that the property of being infinite is to be seen in every closed loop.

Bookmark and Share
report post as inappropriate

Steve Dufourny replied on Mar. 18, 2020 @ 15:28 GMT
Hi to both of You, dear Eckard, it is too much complex to find the real meaning of the infinity, we can of course rank the different infinities inside this physicality and still we know just a small number of these infinities, cantor, Godel or Euler or all the maths works are not the problem, the problem is our limitations inside the physicality and philosophically, we cannot understand inside the physicality all the finite series and all the different infinities simply and it is still more complicated to encircle a kind of infinity beyond this physicality, is it conscious or not and how this thing creates this physicality, is it with strings and wavesm fields or points and a geonetrodynamics or in my model with 3D spheres coded and a gravitational coded aether , we cannot affirm, so that implies a pure uncertainty for our foundamental objects and we cannot predict and rank all simply, like we cannot compute all. We are limited in knowledges simply, even in closed loops you cannot find the answers for these infinities inside this physicality and still less this infinity beyond this physicality, we must recognise this simple fact.What do you Think? Regards

Bookmark and Share
report post as inappropriate


Steve Dufourny wrote on Mar. 2, 2020 @ 09:38 GMT
Hello,

I liked a lot your general essay. Several ideas are very relevant about the links between this quantum mechanics and this GR. I consider personally in my model of spherisation a gravitational coded aether sent from the central cosmological sphere made of finite series of spheres, I tell me that we have a deeper logic than only our relativity and these photons like main essence. This space, vacuum seems more than we can imagine. I have shared your essay on Facebook because it is one of my favorites, regards

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Mar. 2, 2020 @ 10:51 GMT
Many thanks!

Bookmark and Share


John C Hodge wrote on Mar. 3, 2020 @ 15:27 GMT
You demonstrate the point that to synthesize General Relativity (GR) and Quantum theory (QT) seems to require much more complex mathematics. Along the way, for problems of quantum entanglement, Bell inequality, and (I submit) quantum eraser ,a theory would have to be non-local and causal. Also, there are many problem observations in astronomy and cosmology which should be addressed. I prefer to generalize the main goal as finding one theory that describes both big and small of our universe.

I think, like you, that dealing with non-computability could "...break the road-block in finding a satisfactory theory...". That is, non-computability of the mathematics is a problem. I suggest the novel path to this new theory is to remove the mathematics that make the models complex and then to restructure the principles to explain the problem observation and to correspond to GR and QT with approximations.

For example, interpret the Bell inequality so to say NO interaction takes place at less than the speed of light or that ALL interactions take place at a speed much greater than light (such as van Flanern and other observations finding the gravity speed is much faster than light). The Newtonian speculation that interference of light includes the aether wave traveling much faster than the photons and then directing the photons. This suggest the matter causes the aether waves and the aether divergence directs the photons - like in GR. Thus, a further unity can be achieved if the aether is the left side of the GRs field equation (space-time) and the medium supporting real waves in QT. Just these two changes/insights can yield a simpler and more complete model.



I'm unsure how to treat chaos ideas. I think you're correct, we should assume determinism and self-similar (fractal) model even if the reality of the universe may be different.

Hodge

Bookmark and Share
report post as inappropriate


Michael Smith wrote on Mar. 4, 2020 @ 17:10 GMT
Great article Tim. You present your ideas clearly and logically so that even a non-physicist "newbie" such as myself can appreciate the main points.

I was drawn to your title as my (much less rigorous) theory approaches possible unification through fractal geometry as well. I too suggest that the space-time of general relativity may emerge from the higher dimensional geometry of a quaternionic structure, but come at it from a rather unique way - through the cyclical nature of the prime numbers in base-12 (my article is titled "Primarily True").

I posit that my "base-12 prime vibration" as a fractal invariant pattern should emerge in space-time at 10-to-the-power-11 logarithmic fractals (in terms of particle density) as that would represent a complete logarithmic cycle or "octave" of a quaternion power cycle in base-12. This might help explain why there are that many galaxies in the observable universe, suns per mature spiral galaxy, atoms per DNA molecule and even neurons in the human brain. In the gap between each such fractal would therefore be where nature would emerge in an unstructured way, much like your conjecture.

One question: If the quaternion model were purely geometric such as I'm picturing - as simply prime positions on the base-12 circle (thus Euclidean), would it not then become computable after all? If I understand it correctly, Tarski's geometric decidability theorem seems to indicate that would be the case. Any insight would be much appreciated.

Cheers,

Michael

Bookmark and Share
report post as inappropriate


Peter Jackson wrote on Mar. 4, 2020 @ 21:09 GMT
Dear Tim,

Excellent essay. I agree Chaos Theory offers good insight into nature as well as a predictive tool. I think it brave to major on it. Bill McHarris did so well in 2016 with a poor response. I hope you do better. (I drew more on new foundations & fuzzy sets.) I agree that resistance to non-finite maths is problematic, and thanks for reminding us of Hilbert's quote. Was he blind to 'infinite' Pi, space and time?

I was interested in your view that a deterministic foundation to QM should exist, one shared by myself and John Bell. I quote Bell this and last yr and describe a mechanism appearing to show we're correct! But of course too shocking for most to countenance! I hope you'll take a close look.

Beyond your (p6) pairs; if BOTH have N and S poles & parallel axes, and A & B polariser interactions give Poincare sphere surface vector additions, can you think of any reason A & B, by reversing their settings, couldn't reverse their own 'amplitude' outcomes. I found that's NOT a hypothesis Bohr tested!

Your p8. assertion that inequality violation can emerge from an uncomputable deterministic model seems to preclude a physical ontological understanding of process, as all others assume. Does it? If so I disagree so hope you'll explain why you believe so (if Bells proof can be 'sidestepped' as he suggested).

I agree gravity is non-computable, but do you agree that may be in the same way weather parameters are? i.e; All low pressure areas have a density gradient due to rotational velocity, after Bernouili, but all differ slightly and constantly evolve.

Great essay Tim, and I look forward to discussing various matters further, I think best after you've read mine.

Very Best

Peter

Bookmark and Share
report post as inappropriate


Flavio Del Santo wrote on Mar. 11, 2020 @ 16:48 GMT
Congratulations on a nice essay! I think that chaos theory is an underestimated element of the foundations of physics. I think you may find resonance with your ideas in Hoessenfelder's essay (https://fqxi.org/community/forum/topic/3433) and partly in mine (https://fqxi.org/community/forum/topic/3436).

Best of luck for the contest!

Flavio

Bookmark and Share
report post as inappropriate


John David Crowell wrote on Mar. 13, 2020 @ 16:09 GMT
Tim. I enjoyed your article and the inclusion of chaos theory into the discussion of the unification of quantum mechanics and relativity. In my essay “Clarification Of Physics—“ I introduce a new perspective into the unification efforts. In the essay I propose a creation process that emerges from chaos, unifies quantum mechanics and relativity, and creates “our” finite multiverse and the visible universe. I would appreciate your comments on the essay. John D Crowell

Bookmark and Share
report post as inappropriate


Member Jeffrey Bub wrote on Mar. 30, 2020 @ 16:47 GMT
A novel and fascinating idea. It brings to mind Pitowsky's 'Resolution of the EPR and Bell paradoxes' by extending the concept of probability to non-measurable sets.

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Mar. 31, 2020 @ 07:01 GMT
Thanks Jeffrey for these kind remarks. I know what you mean about Pitowski's work. However, on (what I call) the invariant set, the relevant measures can be described by elementary finite frequentist probability theory. The mathematics underpinning undecidability arises only when considering counterfactual states which do not lie on the invariant set. My approach, is simply to deny ontic reality to such states by postulating the primacy of the invariant set. Without this, I think one would indeed be drawn to consider non-measurable sets as did Pitowski. However, the concept of non-measurability does not seem to make physical sense to me - as the famous Banach-Tarski paradox clearly indicates.

PS Reference [18} - my paper arXiv:1804.01734 on invariant set theory - has now been accepted to appear in Proceedings of the Royal Society A.

Bookmark and Share


Vladimir Rogozhin wrote on Apr. 1, 2020 @ 12:13 GMT
Dear Tim,

You write: "Our inability to synthesise general relativity theory and quantum theory into a satisfactory quantum theory of gravity is legendary and is widely considered as the single biggest challenge in contemporary theoretical physics."...

Quantum theory and the general relativity theory are phenomenological theories (parametric, operationalistic) without an ontological basification (justification+substantiation). It makes no sense to “unite” them, let each one work in its own “field”. Problem №1 for fundamental science and cognition in general is the ontological basification (substantiation) of mathematics, and therefore knowledge in general.

You conclude: “From where do new ideas come? Do they pop out of the aether as some random flashes of inspiration with no obvious precedent? Or do these ideas mostly already exist, but in a completely separate setting."

Ideas come to our minds from the primordial (absolute) generating structure that lies both in the “beginning” of the Universum (“top”) and in our heads (“bottom”). The task of physicists, mathematicians and philosophers is to understand the dialectics of Nature (catch on the “net” “Proteus of Nature” using the “goddess of form” Eidothea and “crazy” ontological ideas) and build this Superstructure - the ontological basis of Mathematics (“language of Nature”) and Knowledge as a whole: ontological framework, ontological carcass, ontological foundation. Today we need a global brainstorming session to “assemble” all the ideas for discussing and creating the Ontological Knowledge Base.

With kind regards, Vladimir

Bookmark and Share
report post as inappropriate


Fabien Paillusson wrote on Apr. 11, 2020 @ 15:28 GMT
Dear Tim,

It is a very nice and original idea you have presented in your essay. As many others have said I would probably need a few more reads to grasp all the details though.

Few questions if I may:

- If an underlying fractal geometry can give rise to quantum-like behaviour, how does classicality emerge from this picture, if it does at all?

- Would you have any toy-example with the Lorentz attractor of non-computable counterfactual?

Many thanks.

Best,

Fabien

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Apr. 11, 2020 @ 16:49 GMT
Thanks Fabien. Good questions.

My fractal model has a free parameter N. In the singular limit N=infinity all the fractal gaps close up and the state-space geometry is classical. However, for any finite value of N, no matter how big, the Bell counterfactuals lie in the fractal gaps and the state-space geometry is non-classical. Michael Berry has written about how old theories of physics are often the singular limits of new theories as some parameter of the new theory is set to zero or infinity.

The Cantor Set underpins the Lorenz attractor. Imagine a point X on the Cantor Set and perturb it with a perturbation delta X drawn randomly using the measure of the Euclidean line in which the Cantor Set is embedded. Then the perturbation almost certainly perturbs the point off the Cantor Set.

Such a perturbation can be thought of as corresponding to one of my counterfactuals: although I live in a world where I did X, what would have happened if I had instead done X+delta X? Suppose the delta X is dynamically unconstrained - i.e. something you just make up in your head without consideration of whether it satisfies the laws of physics - then if the world associated with X lies on the invariant set, the world associated with X+delta X almost certainly does not and so the answer to the question "what would have happened?" is undefined.

Bookmark and Share


Edwin Eugene Klingman wrote on Apr. 12, 2020 @ 20:49 GMT
Dear Tim Palmer,

Any essay combining general relativity and Bell’s theorem is a ‘must read’.

In it you show that it’s possible to violate Bell’s inequalities with a locally causal but uncomputable deterministic theory for locally causal spacetime computations. Chaos is powerful, but I’m unsure what the ontological implications are.

A number of authors are concerned whether ‘classical physics’ is truly deterministic, and if not, how is this explained.

If one assumes that the deBroglie-like gravitomagnetic wave circulation is induced by the mass flow density of the particle [momentum-density], then the equivalent mass of the field energy induces more circulation. This means that the wave field is self-interacting. For ‘one free particle’ a stable soliton-like particle plus wave is essentially deterministic. But for many interacting particles, all of which are also self-interacting, then ‘determinism’ absolutely vanishes, in the sense of calculations or predictions, and the statistical approach becomes necessary.

This theory clearly supports ‘local’ entanglement, as the waves interact and self-interact, while rejecting Bell’s ‘qubit’-based projection: A, B = +1, -1 consistent with the Stern-Gerlach data (see Bohr postcard). For Bell experiments based on ‘real’ spin (3-vector) vs ‘qubit’ spin (good for spins in magnetic domains) the physics easily obtains the correlation which Bell claims is impossible, hence ‘long distance’ entanglement is not invoked and locality is preserved.

This is not a matter of math; it is a matter of ontology. I believe ontology is the issue for the number of authors who also seem to support more ‘intuition’ in physics. My current essay, Deciding on the nature of time and space treats intuition and ontology in a new analysis of special relativity, and I invite you to read it and comment.

Edwin Eugene Klingman

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Apr. 17, 2020 @ 07:52 GMT
Tim Palmer re-uploaded the file Palmer_FXQi_Palmer_1.pdf for the essay entitled "Undecidability, Fractal Geometry and the Unity of Physics" on 2020-04-17 07:52:00 UTC.

Bookmark and Share
post approved


Member Simon DeDeo wrote on Apr. 20, 2020 @ 00:11 GMT
Hello Tim —

Wow, this rather blew my mind, and I'm still digesting it.

Let me ask you a really basic question. A chaotic system implies that even approximate knowledge about a path into the far future depends upon the initial conditions—you need to keep going to more and more decimal places in the expansion.

This, in turn, means that we should expect meaningful facts about the future evolution of a chaotic system to be uncomputable. To be really specific, there should be many facts along the lines of "will these three objects collide with each other eventually" whose answer will be uncomputable.

Would it be fair to say that your results here (Eq 6) draw their power from this feature of chaotic dynamics? This would help me in understanding your results better.

So many lovely things here. I had never thought about Lewis' notion of "neighbourhood" in modal logic could be so usefully transposed to counterfactual thinking in physical systems. The idea that the p-adic metric is the "right" notion of "nearby", i.e., modally accessible, is extremely cool.

Yours,

Simon

PS, minor remark Re: finite time singularities in Navier-Stokes—we know (for sure) that they exist in General Relativity, and if you're a hardcore physical Church-Turing thesis person, this is one way we know that (classical) GR is incomplete.

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on Apr. 20, 2020 @ 07:38 GMT
Hi Simon

Thanks for your kind comments.

Yes indeed, if the question you ask of a chaotic system somehow probes its asymptotic states (e.g. "will three objects collide eventually") then one can (likely) reformulate the question in terms of the state-space geometry of these asymptotic states - and my claim is that such geometric questions are typically undecidable. However, the sensitivity of simple finite-time forecasts to the initial state is not itself a illustration of non-computability.

Indeed, I would say that my results (e.g. producing a viable model which can violate statistical independence without falling foul of the usual objections to such violation) arises because of this uncomputable property of chaotic dynamics. I should emphasise that in this picture, uncomputability leaves its mark on finite approximations to such dynamics in the form of computational irreducibility (the system can't be emulated by a simpler system). Hence we can still produce viable finite models where (6) is satisfied.

Re Lewis, my belief is that the potential pitfalls of unconstrained counterfactual reasoning have not been given sufficient attention in studying the foundations of physics. In this we are being beguiled by our intuition. You may be interested a recent paper of mine:

https://www.mdpi.com/1099-4300/22/3/281

which tries to explain why we are so beguiled.

Finally, in classical GR with a cosmic censorship hypothesis, the singularities seem to be hidden from sight and are therefore not as ubiquitous as they might be - if only we could prove it! - in Navier-Stokes!

Tim

Bookmark and Share


Member Seth Lloyd wrote on Apr. 24, 2020 @ 03:06 GMT
Dear Tim,

This is a very nice contribution to efforts to reconcile quantum indeterminacy with classical mechanics by invoking classical chaos theory. Your arguments are convincing. But where do complex numbers and amplitudes come in? They are necessary for quantum mechanics in general and non-local quantum correlations in particular. I'm sympathetic to getting intrinsic uncertainty out of classical chaos. But it seems like something is still missing. Please enlighten us even more!

Yours,

Seth

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Apr. 24, 2020 @ 07:51 GMT
Dear Seth

Thanks for your input. I fully agree that complex numbers are central to quantum theory.

To understand the emergence of complex numbers in my fractal model, could I refer you to the technical paper recently published in Proc. Roy. Soc.A (open access):

https://royalsocietypublishing.org/doi/10.1098/rspa.
2019.0350

on which this essay is based - some aspects...

view entire post


Bookmark and Share


Flavio Del Santo wrote on Apr. 26, 2020 @ 19:59 GMT
Dear Prof. Palmer,

I really liked your esssay and especially how it emphasises the (overlooked) role of chaotic systems for the foundations of science.

I would greatly appreciate your opinion on my essay which is based on the research I am carrying out with Nicolas Gisin. I think our approaches have some similarities, for we also rely on classical chaos to introduce indeterminism in classical physics too.

I wish you the best of luck for the contest, and to get to a prize as you deserve.

Best wishes,

Flavio

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on Apr. 26, 2020 @ 22:16 GMT
Dear Flavio

Thank you for your kind remarks. Nicolas Gisin and I have already discussed some of the matters discussed in your essay and whilst I do agree that your and Nicolas's ideas are very thought provoking, I would say that we are not in complete agreement.

Let me start by remarking that I fully agree that it is possible to treat chaotic classical deterministic systems by some...

view entire post


Bookmark and Share


Michael muteru wrote on Apr. 28, 2020 @ 21:07 GMT
I too concur and oblige that fractals offer structured patterns to which human thought assigns meaning to topological landscapes.Can anthropic bias be key to unravelling New physics that bridge the gap between general relativity and quantum mechanics. kindly read/rate how,why and where here https://fqxi.org/community/forum/topic/3525.thanks

Bookmark and Share
report post as inappropriate


Kwame A Bennett wrote on May. 1, 2020 @ 20:16 GMT
I take a different look at fractals in my essay

Please rate:

Please take a look at my essay A grand Introduction to Darwinian mechanic

https://fqxi.org/community/forum/topic/3549

Bookmark and Share
report post as inappropriate


Yutaka Shikano wrote on May. 4, 2020 @ 23:13 GMT
Dear Tim,

I enjoyed reading your essay and learned a lot of things on the chaos theory. Because I also studied the quantum nature from the viewpoint of quantum walk related to quantum chaos, I would like to know the clarification on the stochastic nature and chaotic nature. From your viewpoint, what do you think about this relationship? As in my essay, the chaotic theory is completely different from the stochastic thing from the viewpoint of computation. Therefore, I would like to know your opinion.

Best wishes,

Yutaka

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on May. 5, 2020 @ 08:07 GMT
Dear Yutaka

Thank you for your question. From the perspective of my essay, stochastic and chaotic dynamics are very different concepts. Let me give an example. In my essay I wrote down the equations of the famous Lorenz model which is chaotic for certain parameter values. For standard chaotic values of the parameters, about 96% of the variance of the model lies in a two-dimensional sub-space of state space. Now one can choose a basis where you retain the dynamical equations in this two-dimensional subspace, but replace the dynamics in the third dimension with a stochastic process. The resulting attractor looks superficially like the Lorenz attractor. However, it differs in one vital regard - all the fractal gaps in the attractor are filled in by the stochastic process.

That is to say, replacing chaotic determinism with stochasticity completely negates my arguments about counterfactual incompleteness (associated with states which lie in the fractal gaps in my cosmological invariant set). Hence my arguments about why the violation of statistical independence is explainable in a suitable nonlinear dynamical framework are nullified if determinism is replaced with stochasticity.

It is for this reason that I am somewhat sceptical of models which attempt to replace real numbers with truncated rationals + stochastic noise will work in explaining quantum physics.

In conclusion, there is a vital difference between chaotic and stochastic dynamics, in my opinion.

With regards

Tim

Bookmark and Share


George Gantz wrote on May. 6, 2020 @ 01:09 GMT
Tim -

An exquisite and erudite exposition on matters far beyond my formal training in math and physics (from some decades ago). I gather that you are positing some level of determinism arising from infinite recursion of fractal attractors. In lay terms, if our frame and timeframe are large enough, we can regain the confidence of determinism from the local instability of chaos, just as statistical mechanics rescues us from the chaos of the independent behaviors of individual particles. Am I following this correctly?

That said, I am dubious that determinism of any sort can be rescued. We can speculate with infinities but we cannot prove anything at all, as the reasoning will always fall short. This verse from the Rubaiyat captures the thought:

XXIX. Into this Universe, and Why not knowing

Nor Whence, like Water willy-nilly flowing;

And out of it, as Wind along the Waste,

I know not Whither, willy-nilly blowing.

Thanks - George Gantz, The Door That Has No Key: https://fqxi.org/community/forum/topic/3494

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on May. 6, 2020 @ 07:42 GMT
Dear George

Thank you for your comment.

My goal is to formulate a finite theory of quantum physics where the fractal invariant set model of quantum physics is a smooth limit as a parameter of the finite model goes to infinity.

Finding such smooth limits is highly non-trivial in quantum physics. For example, if you try to discretise the complex Hilbert Space of quantum theory then you violate the Continuity Axiom of Hardy's axioms of quantum theory - and according to his axioms you would revert to classical theory. In this sense quantum theory is the singular and not the smooth limit of a finite discretised theory of Hilbert space as the discretisation goes to zero.

As Michael Berry has discussed, singular limits are quite commonplace in physics and in some sense represent a discontinuous jump when you go from "very large but finite" to truly infinite.

What I am trying to do is find a finite theory of quantum physics which has a smooth and not a singular limit as some parameter goes to infinity. In practice I can achieve this by assuming that the symbolic labels associated with the fractal iterates of the invariant set have periodic structure. This is entirely equivalent to the idea that rational numbers have a periodic representation in terms of their decimal expansions. The larger the periodicity the closer they are to irrationals.

With this I can effectively interpret the invariant set as a finite periodic limit cycle, but with very large periodicity. As discussed (albeit briefly) in the essay, the property of non-computability is then replaced by computational irreducibility. None of the key properties which allow me to reinterpret Bell's theorem are lost in going from strict non-computability to computational irreducibility.

With regards

Tim

Bookmark and Share


John Joseph Vastola wrote on May. 7, 2020 @ 19:12 GMT
Very intriguing essay! The central idea, (which I understood to be) that one might be able to get around Bell's theorem by having aspects of the underlying deterministic theory be uncomputable in a certain precise sense, is very clever. It's much better than a philosophical monstrosity like superdeterminism, too...Still, I admit I did not fully understand all of the technical details. Maybe I will reread it again.

Here's a philosophical question, though. There's how the universe 'really is', and there's the collection of things we can ever know about it; these sets are almost certainly not equivalent. If there is some sort of deterministic theory that underlies quantum mechanics, but it has the property that it 'looks' probabilistic to us because of uncomputability etc, why should we prefer the deterministic theory? I guess it's possible that ideas like this could help with unification, but it seems to me necessary that the proposed unification would suggest some experiment that would distinguish between the different possibilities in order for that unification to be useful.

More generally, how can we ever know the 'true' behavior of quantum mechanics, given all these clever alternatives?

John

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on May. 7, 2020 @ 20:43 GMT
Dear John

Certainly a new theory of quantum physics should suggest some hopefully experimentally testable differences from quantum theory.

In the technical paper https://royalsocietypublishing.org/doi/full/10.1098/rspa.201
9.0350 on which this essay is based, I present some preliminary ideas on possible differences.

Thanks

Tim

Bookmark and Share


Michael James Kewming wrote on May. 13, 2020 @ 00:00 GMT
Hi Tim,

Thank you for writing a very interesting essay! I certainly fell into the category of 'physicist who finds p-adic numbers exotic'. I have never encountered them but am eager to take a bit of a dive into them.

You certainly raise some very interesting points particularly that undeciability is a property of the underlying state-space of the system and not the physical process occurring in spacetime. Moreover, this lead into a very nice discussion about counterfactuals and free will that I really appreciated.

If I understand correctly, a non-computable theory can violate the Bell inequality. This uncomputable theory is a based on fractal attractors which correspond to the possible eigenstates of the state space being observed i.e determined by the Hamiltonian?

It's an interesting paradigm and am eager to read more. Another question I would ask is how does dissipation alter this paradigm? Does it change the state space where the fractal atractors now change to multiple steady state attractors?

In any case, it was a very thought provoking essay. I hope you have time to take a look at my essay noisy mahcines which considers the limitations of finite resources in undeciable systems.

Thanks,

Michael

Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on May. 13, 2020 @ 07:48 GMT
Dear Michael

Thanks for your kind comments.

Regarding p-adics, I am reminded of a paper I once read by Herman Bondi who said that if children we were taught special relativity in primary school, as adults we would not find things like length contraction and time dilation the least bit strange or unusual. Similarly, I expect, if we were taught p-adic arithmetic in primary school, we...

view entire post


Bookmark and Share


James Arnold wrote on May. 13, 2020 @ 21:50 GMT
Tim, a most sophisticated essay! I can believe that if anyone could accomplish what you've sought, "to provide some basis for believing that these theories [chaos, quantum, and GR] can be brought closer together through the unifying concept of non-computability", you would be the one to do it!

You are no fool on that errand, but regarding chaos, the dependence of a chaotic system on initial conditions, combined with multiple vectors of recurrent interaction, just makes for a recurring deterministic system that may, as you point out, eventually break out into simple (deterministic) turbulence. So chaos: deterministic but not always computable. Quantum theory: un-deterministic but computable at least as a probability. And General Relativity: deterministic and computable. I'm not optimistic.

I didn't understand your reason for thinking "there must also be some deterministic framework underpinning quantum physics."

Finally, more in my wheelhouse, you quote R. Kane “one is free when there are no constraints preventing one from doing as one wishes” – a poor definition that doesn’t distinguish between being determined to wish for something and being merely influenced to wish.

Overall, congratulations on an impressive essay.

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on May. 14, 2020 @ 07:15 GMT
Dear James

Thanks for your kind comments.

Regarding free will. Bell's Theorem involves a mathematical assumption called Free Choice. I have proposed a revised definition called Free Choice on the Invariant Set. This basically means you can't choose to do things which are inconsistent with the laws of physics (the laws of physics in my proposed model derive from the fractal geometry of the invariant set). Put like this, I hope you will agree that this is not an unreasonable definition. We don't say that we are not free because we can't flap our arms and fly like birds!

However, in this definition one cannot predict ahead of time what choices will violate the laws of physics and which will not - this is linked to the non-computability of the invariant set. So, therefore I ask what a more operational definition of free will might be that evades this difficulty. The one I propose is such an operational definition. It's one I personally use in my day-to-day life.

If there is one real takeaway message from my essay that I hope will resonate with you is that in physics the assumption of rather unrestricted counterfactual definiteness is something that has not been analysed enough. I think this issue should be discussed more in Philosophy of Physics circles. For example, in my essay I give a reason why Lewis's counterfactual theory of causation might be faulty because of an implicit use of Euclidean distance in state space.

Best wishes

Tim

Bookmark and Share

James Arnold replied on May. 16, 2020 @ 12:56 GMT
Tim, does randomness (defined as something uncaused or unprovoked) defy the laws of physics? It is used regularly in quantum physics to describe the unpredictable. I maintain that it is the best explanation for nothing happening at all. I suggest "spontaneity" as an explanation for anything from the quantum level to human inspiration, which by definition exceeds the laws of physics, but is more credible than nothingness.

Bookmark and Share
report post as inappropriate

Author Tim Palmer replied on May. 16, 2020 @ 13:04 GMT
James

Personally, I have considerable difficulty with the concept of randomness in fundamental physics (even though it is an incredibly useful concept for many areas of applied physics). If you give me a bit string 010010....01 that you claim has been generated randomly, I will give you a deterministic rule for generating that same bit string. Now some might say that randomness is informationally incompressible determinism. Well I would say that in practice the two may well be indistinguishable. However, at a fundamental level the latter is generated by a deterministic rule and the former, presumably, is not. In my view the sooner we get back to thinking about physics deterministically (even though it may be computationally irreducible determinism) the better!!

Best wishes

Tim

Bookmark and Share


Michael Alexeevich Popov wrote on May. 14, 2020 @ 09:25 GMT
Tim,

My intuition suggests that Bell theorem could be formulated also as " UUU - mathematical problem" in physics. Hence, there is some so - called "nonclassical tacit math" behind Bell as well?

Thank you for essay.

Michael

Bookmark and Share
report post as inappropriate


Member Emily Christine Adlam wrote on May. 16, 2020 @ 13:09 GMT
This is a really exciting essay; I'm really intrigued by the connections you suggest between quantum mechanics and chaos theory, and am now keen to learn more about this area.

I did have one general question about the motivation for this approach. If I understand you correctly, the idea is that by constraining the state of the universe to evolve on some uncomputable fractal subset of state...

view entire post


Bookmark and Share
report post as inappropriate
Author Tim Palmer replied on May. 16, 2020 @ 13:57 GMT
Dear Emily

Thank you for your interesting and important questions. In replying I need to make sure I don't end up writing another paper!

As far as my motivation is concerned, I did my PhD many years ago in GR (under the cosmologist Dennis Sciama) and in truth the reason why I have got so interested in Bell's Theorem is not because I am interested in Bell's Theorem per se, but rather...

view entire post


Bookmark and Share


Member Tejinder Pal Singh wrote on May. 17, 2020 @ 18:01 GMT
Dear Tim,

It was a pleasure reading your essay. and the valuable insights it gives. Would you happen to know if Connes' non-commutative geometry formalism would classify as uncomputable?

As regards quantum gravity, I beg to submit that I have made important progress recently, and proposed the theory of Spontaneous Quantum Gravity, described for example in my paper

Nature does not play dice at the Planck scale

Independent of anything to do with the present contest, I will value your critique of my theory. I would like to reach out to many physicists with a request to examine this theory.

Many thanks,

Tejinder

Bookmark and Share
report post as inappropriate


Author Tim Palmer wrote on May. 17, 2020 @ 18:33 GMT
Dear Tejinder

Connes comments in his book that non-commutative differential geometry provides a way to represent the measure of fractal sets such as the Julia set. Since these fractionally dimensioned sets are non-computable, then non-commutative geometry and non-computable geometries are related.

Hence, perhaps there are some interesting connections to be made between my invariant set model and Connes' non-commutative models of quantum physics.

Having said that, non-commutative geometry is not an area of mathematics of which I have any great knowledge.

I will take a look at your essay. The title sounds very appealing to me!!

Best wishes

Tim

Bookmark and Share

Member Tejinder Pal Singh replied on May. 18, 2020 @ 00:41 GMT
Thanks Tim! This connection between non-computable geometries and non-commutative geometries is extremely interesting! I did not know about it. My new quantum theory of gravity builds on Connes' non-commutative geometry and Adler's trace dynamics.

Best,

Tejinder

Bookmark and Share
report post as inappropriate


Torsten Asselmeyer-Maluga wrote on May. 18, 2020 @ 21:17 GMT
Dear Tim,

what a wonderful essay and it rings a bell.

Now since 8 years I studied general fractals (better known as wild embeddings) to get a spacetime representation for quantum states. You also discussed this interesting relation and you are right, there is a direct link between such objects and general relativity as well. The space of leaves of a foliation is also a non-commutative geometry (a la Connes) and this space is related to wild embeddings (or fractals) as well.

Amazingly, these connections are naturally related to the structure of spacetime (I mean the 4-manifold). If you choose another differential structure then you get automatically these connections. But enough for now.

I enjoyed very much reading your essay and gave them the highest score.

Maybe you are also interested to ream my essay

Because of Corona, I was to late this year....

Best wishes

Torsten

Bookmark and Share
report post as inappropriate


Jonathan J. Dickau wrote on May. 18, 2020 @ 23:23 GMT
Hi Tim,

I read your essay a while back and I have not seen any comment from you on mine. Since there is some overlap in our topic emphases; it would be nice to have your opinion.

All the Best,

Jonathan

Bookmark and Share
report post as inappropriate


Login or create account to post reply or comment.

Please enter your e-mail address:
Note: Joining the FQXi mailing list does not give you a login account or constitute membership in the organization.