Gravity is not fundamental; or is it? by Jonathan J. Dickau

Jonathan,

The idea that asymmetry is significant seems very reasonable to me as an engineer. We are intensively taught thermodynamics and some of the things you describe are phase-changes in my opinion.

The Mandelbrot Set is new to me. You reference two coordinates when discussing this set but the figures you present do not appear to have marked axes. The left-right symmetry is obvious, so I assume that is the vertical axis. I'm less clear as to the location of the horizontal axis.

My undergrad Physics textbooks were Sears & Zemansky and Halliday & Resnick.

All in all this is a well written and thought provoking essay. Well done.

Best Regards,

Gary Simpson

Reading now. Will comment as I go along. By and large

liking what I'm reading. although gravity theory is not

my forte by a long shot.

"Along the way; we saw the creation of space give way

to the production of particles, and then to nucleosynthesis,

while the universe was still an energy soup - where

matter and energy are interchangeable and ever interchanging,

because the mean interaction distance is so small."

== Another evident asymmetry in this universe is matter/antimatter.

That is, we seem to live in a matter dominant universe. I address

(solve) this asymmetry in my last paper, but whether or not it

is correct, unless the universe started symmetric, and all the

antimatter got sucked away in tiny interaction asymmetries, if the

universe was born with this asymmetry, then there can't have been

a time when it was all energy. But maybe that doesn't matter

(pun intended).

==It's unclear to me why the Mandelbrot Set should be singled out.

There are infinitely many fractal sets that one can generate by

iterating functions of a complex (or quaternion, or octonion) variable.

Of course, asymmetry is rampant in this field.

"However; exploring the possibility that gravity can be explained as a

consequence of other forces yields insights that may help us figure out

how to craft better unifying theories than we might if that option was

off the table. The relevance of those insights likely reflects the

pervasive presence of asymmetry in the natural world. I think that

our preoccupation with symmetry has blinded some Physics folks to the

value of asymmetry in Physics, and it will take considerable effort

to learn the other side of the story."

== I have been aware for a little while that there are are some who

wonder if gravity needs to fit into the QFT/symmetry set of notions

about how forces/interactions work. Non quantum GR isn't really a

theory of interactions. "Spacetime tells matter how to move; matter

tells spacetime how to curve."* (Wheeler) Matter isn't being pulled,

or pushed, until it encounters an obstruction, like our feet on the

ground. Anyway, I always harbor hope that some alternative viewpoint

will turn out to have more Truth than the mainstream's.

*You know, that's a good metaphor for what we're all doing. We all

have an intuition about how things might work - a kind of intellectual

geodesic. It is unwise to stray from your personal geodesic, which

is your personal path of least resistance (right or wrong). Keep

at it; it's worth pursuing. But maybe minimize introducing words like

"likely" into the discussion. I have no idea how you'd quantify the

probability of an unproved idea being valid. :)

Dear Jonathan J. Dickau,

Before the surface of any stone can fall to earth, it first has to be somehow hoisted above that part of the surface of the earth it is likely to fall upon.

Joe Fisher, Realist

Dear Jonathan Dickau,

This is (in my opinion) your best FQXi essay by far. You say "things from the Mandelbrot set ... teach lessons in physics." I would say that you gain insight from the Mandelbrot set and teach yourself. Regardless, your focus on asymmetry is fruitful. I had not thought of the

"near perfect symmetry at higher magnification... [and] asymmetrical at lower magnification."

I agree with you that "entropy can be characterized by spreading and sharing." As I've noted in earlier essays, energy is transmitted through space and time. If that energy crosses a systemic threshold and effects a change in structure of the system, then that 'in-formation' of the system is a record of information. One can show that Bekenstein's holographic entropy formula based on "screens storing information" can be derived exactly in terms of energy only, never mentioning, using, or even conceiving of information.

My point is that if energy is fundamental, and one can define an abstraction, say information or entropy, and derive abstract results, then a clever person can often begin with the abstraction and work back toward the fundamental as if it "emerges from" the abstraction, as Verlinde does. Barbour does something similar with time.

The same applies to 'quantum information', as you so well describe at the top of page 3. I of course do not deny the obvious usefulness of the abstraction of information, but what is fundamental is energy.

Jacobson asks "how did classical general relativity know that horizon area would turn out to be a form of entropy?" As I noted, the horizon formula can be derived strictly as a distribution of energy. Since thermodynamic entropy is derived in terms of energy distributions, and since formulaic similarity between 'thermodynamic entropy' and 'information entropy' leads [as ET Jaynes notes] to "proving nonsense theorems", it should not be surprising that clever persons can run the derivations backwards, from abstract the fundamental. Here fundamental is made to seem to "emerge" from abstraction. That appears to be quite the fashion in physics today. Hence Jacobson and Verlinde.

You, on the other hand, observe:

"...that asymmetry is as fundamental to physics as symmetry takes some getting used to."

Hooray for you. You mentioned SU(3)xSU(2)xU(1) is fundamental, but SU(3) is a valid symmetry only for equal masses, yet it is applied in cases where masses differ by two orders of magnitude. As you note,

"there is a tendency in physics to oversimplify."

You "see condensation as a general feature of all theories of emergent and induced gravitation." While I wholly reject "emergent gravitation", I heartily concur with you on the importance of 'condensation'. And I do agree with you that

"Asymmetry is as much a fundamental to physics as symmetry is."

I think this is a major contribution to this particular essay contest.

Gravity is fundamental, not emergent, and the key asymmetry is that expressed in the gravito-magnetic equation

curl C = - mv

where C is the gravito-magnetic field, m is the mass/energy density and v is the velocity. The - represents the fundamental asymmetry that is left-handed circulation. This underlies the asymmetric left-handedness of the universe from galaxies to neutrinos to biology. If Mandelbrot brought you to this insightful understanding, you have used it well.

Congratulations on a superb essay,

My very best regards,

Edwin Eugene Klingman

Jonathan,

Welcome back. You opening greeting is graciously welcoming as well. Your essay poses and answers a lot of questions in physics, as well as indicating the paradoxical nature of physics and the subject we are treating.

"Determining what is fundamental in Physics, and what is derivative, has long been a subject of debate among physicists, mathematicians, and philosophers." Your introduction rightly ponders on the distinction of fundamental or derivative -- must be one or the other? The four forces are usually considered fundamental but are they derived from one force due temperatures > 1 billion Kelvin or consequences, so not fundamental? I think all of our essays should or do open a Pandora of other questions as we try to cover all the bases or options. One essay says that symmetry is fundamental, giving a good argument. I also mention gravity and EM forces as long range and weak and strong as short-range arising from one force, reciting the orthodox view, but point out that we need to keep open minds.

Your essay, as I said, keeps an open mind, indicating a preferential view that might change. I do the same.

Regards,

Jim Hoover

Dear Jonathan,

Your question about the fundamentality of gravity is important, but there is a related question - what is gravity?

In my own essay, "Fundamental Waves and the Reunification of Physics", I argue that gravity is not, as we have been taught, the curvature of spacetime. On the contrary, on the microscopic level, everything is comprised of oscillating waves. Gravity is simply the (very weak) modulation of the wave frequency by every other fundamental wave in the universe. Furthermore, there is no abstract spacetime. Instead, time and space are defined locally by the frequency and wavelength of fundamental quantum waves. This simple, unified picture states that the speed of light is NOT constant, but decreases in the vicinity of a star. This gives the accurate trajectory of a light beam bending near a star. This is simply refraction, not bent spacetime.

I further suggest that black holes and event horizons are not real, but are rather mathematical artifacts. There are certainly compact gravitational objects in galactic centers, but we know very little about their true nature.

This picture has no quantum entanglement, which has important technological implications. In the past few years, quantum computing has become a fashionable field for R&D by governments and corporations. But the predicted power of quantum computing comes directly from entanglement. I predict that the entire quantum computing enterprise will fail within about 5 years. Only then will people start to question the foundations of quantum mechanics.

Alan Kadin

Gravity is not fundamental; or is it?

Jonathan,

'Fundamental' is a descriptive term, an adjective. As to whether the term applies to a specific subject or is intended to reference a universally applicable element depends upon the context in which the term is used.

In 1916 Einstein amended his Special Theory of Relativity in the interest of drawing gravity into the scope of a more comprehensive or general theory. His means were to declare gravity a misconception, an effect rather than a cause, brought about by the uneven distribution of mass in the universe.

Thus we are led to the inevitable question: What is the cause of gravity? Vacuum is the dominant medium in the cosmos and so-called gravity is simply its means of filling voids. A kind of push-me-pull-you game that we interpret from the earth as a 'pull' but which seen from outer space would be recognizable as a 'push'.

So there you have it, and there you don't! The pull of what we call 'gravity' is 'fundamental' when considering earth-bound subjects, but not 'fundamental' where it is considered in the context of the greater force of vacuum.

"Reality" is place and time dependent. Thus dinner time in Timbukto on Thursday is breakfast time in Fiji on Friday; just as surely as 'up' in Timbukto points in the same direction as 'down' in Fiji.

Jonathan, with each essay contest you improve your ideas and they become increasingly interesting. The Mandlebrot set is a great example of how universality works when there are scaling laws, and how symmetry emerges. As you have explained in your own words the Mandlebrot set exhibits a self-similarity symmetry at Misiurewicz points which is approximate at large scales, but it gets more exact as you zoom in. Similar things happen in physics in different contexts. The renormalisation group in quantum field theory and in thermodynamics is an example of a similar phenomena except that the self similarity improves as you zoom out to larger distance scales rather than zooming in. Another difference is that the renomalisation group gives a continuous self-similarity symmetry whereas the Mandelbrot set is self-similar in discrete iterative steps.

One of the most interesting parts of your essay is the description of how octonions arise at some points. I was not aware of this. Emergence of symmetry in systems of universality with scaling is fundamental to my ideas on the emergence of the laws of physics from complex systems of mathematical possibilities. My claim is that the process of quantisation is the iterative step from which symmetry emerges.

In your proposal there is a twist. if I have understood correctly You say that the Mandelbrot set is not merely an example of emergence but is in fact the perfect description of it. You also say that the asymmetry is fundamental. This can happen. If you zoom in on a thermodynamic system the emergent behavior eventually breaks down and you see the interactions between molecules from which thermodynamics emerges. In quantum field theory you may also find that a theory such as QCD is not exact at high energies, then the SU(3) gauge symmetry may be approximate or not. The same goes for the diffeomorphism symmetry of gravity. My long held belief has been that diffeomorphism symmetry is replaced with permutation symmetry over spacetime events at small scales. This fits perfectly with entropic theories of gravity.

Your idea that the Mandelbrot set is somewhere down there at the bottom is not as daft as it sounds. It is the defining characteristic of universal behavior that it turns up in many different circumstances and that is the case for the Mandelbrot set too. Whether Mandelbrot is the whole, or some part of something larger that encompasses all forms of universality is another question.

There is an ongoing debate about whether gauge symmetry becomes an approximation at higher energies, or alternatively that it is revealed as the residual symmetry of a larger one. It may depend on whether you think the limit of the iterative process is taken or alternatively that there is a cutoff scale at which it stops. In particle physics it looks like it stops, but my view is that at the deepest level the limit must be taken so that a huge exact symmetry emerges. This is necessary to hide the irrelevant details of axiomisation and also to protect us from Godel's undecidability. If it turns out that there is a cutoff and the universal symmetry is only approximate then the universe could be a much stranger place. That is certainly something to think about.

Dear Jonathan

Intriguing Essay. Congrats!

Here are some comments:

1) Einstein's elegant vision of gravity is the reason for which I decided to become a researcher. Thus, it is very difficult for me thinking that gravity is not fundamental.

2) On the other hand, I agree with you that all forces could be the consequence of just one unified field of interactions and sub-ranges thereof. In that case, not only gravity but also the other forces should be "entropic and emergent". This could, in principle, lead to a global geometric interpretation of physics where asymmetry and/or symmetry should be even more fundamental.

3) Like you, I am not sure of whether gravity actually is a fundamental force of physics or not, despite I am inclined to the positive answer. Paraphrasing Einstein, in any case it is a very interesting problem.

Congrats again and good luck in the Contest. Maybe you could be interested in my Essay, where I discuss physics unification from another point of view with... Albert Einstein!

Cheers, Ch.

Sorry, here is the correct link to my Essay:

https://fqxi.org/community/forum/topic/3077.

The link help page seems to do not work.

Jonathan Dickau,

You begin to address the makeup of the universe mostly in your abstract. You ask if gravity is fundamental. In the process you summarize a mistaken analysis of gravity. Can you convert?

The 'weak' definition of gravity in the current metaphysics of the standard model is just wrong. The reality is hidden by the definitions of gravity. It is an attraction via Newton or bent space via relativity. Neither of those forces surround masses as do the comparative forces. Attraction is the net result of gravity upon a point on the mass surface. Attraction is thought of as a non-physical linear pull toward the center of (earth) for example. There is a problem here. The physical solution is that gravity must be a push. The gravity source is a push, the resulting impression is attraction. With the source as a push, it pressures matter from all sides. The sum of all 3 dimensional pushes is not weak! As such it creates the spherical shapes of spatial bodies and holds them and us together. Gravity is the source of the other forces reversing your mention of gravity being the consequence of other forces.

It takes time to adjust your perspective. The hard issue is explaining unbalanced pushes that result in 'attraction'. Gravity is EM radiation traveling in all directions throughout space at speed C. The radiation penetrates matter and is diminished within. The 'net' result on the other side results in unbalanced gravity. The push downward there exceeds the push up from the surface by the exiting radiation.

One revelation is how gravity becomes unbalanced allowing the 'net' force to push orbitals forward in their orbits while simultaneously pushing them downward. The idea of eternal motion goes away. There is much more to learn for those that are interested.

Paul Schroeder