Dear Arturo

Your question seen to be interesting. But what about indications

on the non-commutativity of spacetime?

( See for instance Annals of Physics

Volume 386, November 2017, Pages 305-326)

In my working project: "TOWARDS GRAND UNFIED THEORY OF EVERYTHING......" wherein are also my working papers modeling mathematical physics the quantum relativity is purported to be a real problem solving aspect of grand unification, I will infer quantum represents microassymmetrical while the relativity represents macrosymmetrical aspects. Per your article here and my interpretations then it will be reasonable to hypothesize gravity to be the missing link, especially since gravity helps provide force to make symmetrical entity.

Yang Mills type 2x2 matrix that I have analyzed, that my working papers publish based mathematically on Helmholtz theorem, may shed light on approach necessary to solve logically and quantitatively the evasive problem of gravity that was making grand theory a vexing conundrum.

My hope having global international physics conference by 2020 or so may provide proper grand unification platform to tackle the paradoxical query.

Hope more will come forward meaningful approving outcome.

Dear C.A.Z., thanks a lot for the useful reference, that uses an approach opposite to ours. For the readers, the paper C.A.Z. is talking about is:

Article Revisiting quantum mechanics on non-commutative space–time

Dear Arturo,

Non-commutative space-time is indeed applicable, since the Lorentz invariance is found incorrect by Louis deBroglie in his 1937 book: “La Physique Nouvelle et les Quanta”:

"Il y a néanmoins une différence essentielle entre la contraction de Lorentz-Fitzgerald et celle qui résulte, d'après Einstein, de la transformation de Lorentz. La première, en effet, était censée être une contraction réelle provoquée par le mouvement absolu du corps dans l'éther, tandis que la seconde est une contraction apparente relative au second observateur: elle dérive uniquement de la façon dont les divers observateurs font leurs mesures de distances et de durées et de la transformation de Lorentz qui exprime mathématiquement la relation entre les mesures ainsi effectuées par les deux observateurs.

La contraction apparente des longueurs a comme complément le ralentissement apparent des horloges."

.../...

“En particulier, on peut parfaitement justifier le fait paradoxal que la contraction des règles et le ralentissement des horloges sont des apparences réciproques, c'est à dire que si deux observateurs en mouvement relatif uniforme sont munis chacun d'une règle et d'une horloge, les deux règles et les deux horloges étant de construction identiques, chacun des observateurs trouve que la règle de l'autre est plus courte que la sienne et que l'horloge de l'autre retarde sur la sienne. Si surprenante que puisse paraître au premier abord cette réprocité, elle s'explique aisément quand on examine avec soin la théorie.”

By this deBroglie says that SRT accounts only for the deformation of the measuring data between reference frames, not for the very properties of the objects in reference frames.

Dear Thierry, thanks for your skillful answer.

The problem you raise is an old one...

https://www.researchgate.net/post/In_special_relativity_a_fast_sphere_is_perceived_as_squeezed_or_unchanged

To be honest, I prefer the Einstein's version, instead of the deBroglie one. It gave me the possibility to try an unusual comparison (not just an analogy!), that can be experimentally tested:

Article Einstein and the physics of the mind: Comment on "Physics of...

Dear Arturo,

I think looking at these two papers could partly answer your question:

Article Spin Hall effect and Berry phase of spinning particles

Article Spin Hall effect of Photons in a Static Gravitational Field

If you find this interesting, i will be happy to discuss more about it.

Dear Arturo,

If you read deBroglie's text carefully, you will see that he says that his view and Einstein's are the same. Also Einstein's text that you cited in https://www.researchgate.net/post/In_special_relativity_a_fast_sphere_is_perceived_as_squeezed_or_unchanged

says the same.

It is precisely the deformation of the measuring data between reference frames, not the very properties of the objects in reference frames themselves.

If I'm not aware to be embedded in a reference frame, I see an object queezed, and I do not know what are the ones that you call "the very properties of the objects"...

Dear Marius, very interesting... I will go through your papers.

In other words, dear Thierry, think to the Unrhu effect... in that case, the real properties of the object do not mean anything...

Dear Arturo,

The very properties of an object (in the SRT context) are their inertial mass, length and time. They don't change due to velocity, except if one considers matter as self-trapped lightwaves. In that case, a kind of "Poisson" contraction could occur: broadening and shortening of the object. However, no time or mass changes.

Only the measurement signals between inertial reference frames are deformed, and by extension, between any reference frames.

The Unruh effect has never been proven to exist, nor has the Lorentz invariance, time dilation, mass increase or length shortening ever been proven.

https://en.wikipedia.org/wiki/Unruh_effect

What happens is that FERMILAB and CERN cannot accelerate particles without limit because of the retardation of the fields by the speed of light. The electric field about charges is deformed by this retardation at high speeds, and becomes almost only radial, perpendicular to the velocity vector. In the line of motion, the electric field vanishes almost totally.

This high speed induces a strong circular magnetic field, perpendicular to its velocity vector, and forms an induced Lorentz Force, which compresses the charged particle radially, resulting so in a longer lifetime.

Also, no external field can continue accelerating a charge that only gets an electric field that is perpendicular upon the velocity vector, because no direction can be given to it.

Moreover, also remember that atomic clocks are electromagnetic systems in the first place.

The theory of retarded fields has been fully developed by Oleg Jefimenko in his great books.

Well again I cannot aggree with such comment "Unruh effect has never been proven to exist, nor has the Lorentz invariance, time dilation, mass increase or length shortening ever been proven."

Respect to the Unruh effect I am also not sure that it has been proven but the others? The scientific academic literature has so many confirmations of these basic predictions/ingredients of SR and GR that it is hard to pick up just a few...there are thousands of publications about these topics in well known scientific journals: Phys. Rev., Annals of Physics, Nuclear Phys., Phys. Lett., and so on and on...just have to pick up...

Dear C.A.Z.,

To be honest, I agree with you...

However, we are falling once again in the controversial issue of length contraction, that, as you can see, raise opposite feelings (also in my previous question, where an harsh discussion took place...).

I would like to focus on my terrible dilemma: could the gravitational field be the source of the "loss" of quantum noncommutativity, in the relativistic, macroscopic world?

Dear Arturo

I understand your point now. Thanks for the explanation. My point of view is different. It is based on the statistical/probabilistic view of quantum mechanics. For example: there is an essential property of quantum mechanics when facing a quantum mechanical treatment of identical particles. In classical mechanics the particles are distinguishable. In quantum mechanics they are indistinguishable. This behavior makes an essential difference in the mechanical quantum treatment and in the classical treatment of identical particles. In quantum mechanics the Hamiltonian that describes the behavior of identical particles, by the fact of their indistinguishability, is symmetrical. And all the observable physical quantities of a system of identical particles do not depend on the exchange of coordinates (of space, spin, isospin, etc.) of the particles. Thus, the squared module of the quantum-mechanical wave function that describes the system is invariant against the exchange of these coordinates, since, in quantum mechanics, it is the squared module of the wave function that is physically measurable. As a consequence of these elements described above, there are only two possibilities of symmetry for the TOTAL wave function of the system: symmetric or anti-symmetric. In the first case the wave function describes systems obeying the Bose-Einstein statistics (Bosons) and in the second case the Fermi-Dirac statistics (Fermions). These consequences concern quantum mechanics. Which is evidently conformed by the Heisenberg's uncertainty principle. Planck's constant represents the key to the portal that separates the quantum world and the classical world. In my view, there is nothing to do your interesting questioning with gravity in order to change the statistics and therefore the conditions of symmetry and asymmetry between dynamic operators associated with the quantum world when we examine physical systems in the classical world.

Dear C.A.Z. (what is your name?),

thanks for the rich explanation.

Therefore, how do you explain quantum entanglement and decoherence?

Cesar

Dear Arturo

About those topics I found very interesting the approach of the author below. His view is very interesting on the framework of quantum optics.

Title: From quantum to classical: Schrödinger cats, entanglement, and decoherence

L Davidovich

Published 25 May 2016 • © 2016 The Royal Swedish Academy of Sciences

Physica Scripta, Volume 91, Number 6 

Focus on Quantum Optics in the International Year of Light

Abstract

Since the beginning of quantum physics, the relation between the properties of the microscopic quantum and the macroscopic classical world has been an important source for the development of the theory, and has led to new insights on the role of the environment in the transition from quantum to classical physics. Decoherence affects both coherence and entanglement of open systems. Quantum optics and cavity quantum electrodynamics have allowed detailed investigations of this phenomenon, within the framework of microwaves and light waves. In this paper, I present a personal account of theoretical and experimental developments that have led to the probing of the subtle frontier between quantum and classical phenomena.

Dear Arturo

The whole article can be found in

http://iopscience.iop.org/article/10.1088/0031-8949/91/6/063013/pdf

Dear C.A.Z. Vasconcellos,

You wrote: "The scientific academic literature has so many confirmations of these basic predictions/ingredients of SR and GR that it is hard to pick up just a few...there are thousands of publications about these topics in well known scientific journals: Phys. Rev., Annals of Physics, Nuclear Phys., Phys. Lett., and so on and on...just have to pick up..."

That is absolutely irrelevant. There is no proof whatsoever that the events that can well be explained by electromagnetism would possibly be superseded by SRT.

Even if 10 million people will publish papers on that, it will not change these facts.

Hi Thierry

Sorry, but I cannot aggree with your statement! I do not want to make it personal but what matters to science are scientific facts and scientific explanations of these facts. The results of these facts are published in scientific papers judged by scientists. This is the way science develops. To be accepted by the scientific comunity any idea, model, scientific proposal etc must be tested, analized, confronted with other ideas, models, observations, experiments and so on. This is the reason I told you about thousands of scientific publications. In confrontation to your statements against ST and GR. GR in particular cannot explain the behahior of the universe only in the domain of strong gravity / high energy! GR has excelent results in other domains.

Dear C.A.Z. Vasconcellos,

I have not the slightest idea of what you are talking about.

But certainly Pavlov and his dog have.

Ok Thierry

No problem

I have been reading Gary Bowman's "Essential Quantum Mechanics." He has an interesting chapter on commutators that may help with your question. He discusses what it is that makes the property of non-commutation work. He makes an interesting point: "if two operators share a complete set of eigenstates, they commute. In that case, we are free to change the order of operation of two such operators in a calculation, regardless of the state the operators may act upon." (p, 85)

In other words, the idea that all quantum mechanical calculations do not commute is wrong.

He goes on to show that position and momentum do not share the same set of eigenstates, plus they appear to be related because of their shared uncertainty relationship. This is why position and momentum do not commute.

This may also offer an insight into why communativity is a property of the macroscopic world. For example, the position state and momentum state of macroscopic objects are considered to be unrelated in classical physics and there appear to be no significant superpositions involved with moving from one operator to another.

Perhaps this might help.

Dear C.A.Z. Vasconcellos,

I gave you the complete vision of Louis deBroglie about SRT from his book, in which he said that Einstein and himself found that SRT only expresses the modification of the measuring signals between the inertial reference frames, in contradiction with what you claim.

Until now, you didn't even bring the beginning of a scientific reply.

No; and the statements made in the followup don't make sense.

Dear Stam, hi!

I was wandering why you did not yet answer to my propositions!

No.

We can read in so many papers published in so many important scientific journals about the extraordinary success of GR. As I said It is hard to pick up some. I cite a few.

I start with a practical one: the accuracy of the Global Positioning System (GPS) depends on corrections from GR. According to GR a clock traveling in the weaker field of the orbit of a GPS satelite ticks more rapidly than a clock in the Earth. So GR corrections are essencial for a more precise location. Thus when someone uses the GPS in his cell phone he is inadvertently testing the accuracy of GR. (See for instance Peter Edmonds).

In astrophysics, we can cite for instance tests of GR through Chandra observations. Chandra observations agree with the predictions of GR involving the rate of growth of galaxy clusters and aspects of the accelerating expansion of the Universe.

The knowledge of the gravitational lensing effect for instance, which allows a better knowledge about dark matter in the universe, is a consequence of GR predictions. A combination of X-ray data from Chandra with optical data from the Hubble Space Telescope has allowed to map dark matter in the universe. I particularly did recently calculations of the mass-radius relation of neutron stars with dark mass content (WIMPs), imersed in the repulsive background of dark matter, as predicted by the pseudo-complex general relativity, and I found a maximum mass very close of Ruffini's prediction of 2.9 solar mass.

A direct measurement of the spin of the black hole in the quasar RX J1131-1231 has confirmed recently another prediction of GR: that gravitational lenses act sometimes as magnifying glasses, increasing the light from distant objects. (See for instance Peter Edmonds references on this topic).

The recent detection of Gravitational waves by LIGO represents a great achievement of GR.

Gravitational waves produced by close pairs of white dwarfs, neutron stars or black holes, is one of the most important predictions of GR. For instance the shrinking separation of double stars has been recently explained by energy lost with the emission of gravitational waves. Recoil kicks of large astronomical objects may have their origin on gravitational waves. This prediction of GR was the main reason for the recent discovery of a

supermassive black hole ejected from its host galaxy after collision and merging with another black hole and the

recoil kick from gravitational waves.

This result validates GR in the region of strong gravity.

Dear Arturo

You said: Dear C.A.Z. (what is your name?),

thanks for the rich explanation. Therefore, how do you explain quantum entanglement and decoherence?

As I told you, my point the view is based on the statistical/probabilistic view of quantum mechanics. On the other hand I cannot see any comection involving quantum mechanics and classical gravity. The scales are so different... Moreover quantum mechanics is based on very restrictive components: dynamical non-commutative complementary quantities, Heisenberg principle, Fermi-Dirac and Bose-Einstein statistics, the Planck constant as the key singular limiar quantity separating the classical and quantum worlds and so on...The classical formulation of General Relativity has no connection to these elements. It is a geometric theory. I do not see how gravity can affect the statistics and commutation rules of quantum mechanics. I do not see this way any conection of gravity to quantum entanglement and decoherence.

Dear C.A.Z. Vasconcellos,

You wrote: "A direct measurement of the spin of the black hole in the quasar RX J1131-1231 has confirmed recently another prediction of GR: that gravitational lenses act sometimes as magnifying glasses, increasing the light from distant objects."

Can you please explain the following :

1) What prediction? How would Einstein have ignored the results of the magnificient solar eclipse in 1914, visible from Sweden to Turkey, of which Einstein could get all the photographs he wanted?

https://en.wikipedia.org/wiki/Solar_eclipse_of_August_21,_1914

2) How could Eddington have measured, in terrible hot circumstances, from the surface of a hot desert, some conclusive results?

3) How has a "direct" mesurement been made of the rotation of a Black Hole, which is by definition of the word: Black, except by suppositions through a theory?

dear Arturo, < The unexploited unification of general relativity and quantum physics is a painstaking issue. > I have the results of the unification (of RTand QT). therefor I used distibutions theory and found out that some presumptions are to revise because the results are false.

Hi Thierry

I am sorry but in my opinion we cannot discuss scientific issues based on wikipedia citations. Please bring scientific questions published in scientific journals to the discussion and I will be happy to discuss them with you.

Dear C.A.Z. Vasconcellos,

Do you want to deny that there was a magnificent solar eclipse in 1914, visible from Sweden to Turkey ?

Isn't it a very unprofessional way to try eluding my three scientific questions, probably because you were just parroting the information you gave, without having verified or understood the precise content?

Dear Sydney

Thanks for your kind message. I am a nuclear physicist working presently in nuclear astrophysics, modeling compact stars using quantum relativistic effective models in the realm of general relativity. Of course mass and energy may in some circunstances shape the geometry of space time and shape this way, from the "geometrical warping of spacetime point of view", gravity. Now, why did I mention that I am a nuclear physicist? Because my scientific background is based on the study of the structure and dynamics of the nucleus under the action basically of the nuclear force in its two levels, with baryons and mesons and/or quarks and gluons degrees of freedom. Sometimes I read some questions and answers in research gate and it seens some people discuss theories without taking into account a crucial aspect in physics: the dynamics of physical systems under the action of a few or even all the four forces of nature. And also the different scales associated to these forces. And in order to take those effects into account you have to build for instance dynamical couplings involving different forces of nature, via the introduction of coupling of Lorentz fields with different coupling constants. GR is a geometrical theory. And the scales for which the GR description is relevant are far way from the corresponding scales in quantum mechanics. From the dynamical point of view I do not see how gravity can influence quantum observables because there are no dynamical couplings involving gravity and quantum systems which would change or mix or affect the wave functions of these quantum systems and the corresponding outcomes of experimental apparatus in order to produce any kind of entanglement. Our immagination in physics must rely on facts. I do not know any article published in any scientific peer reviwed journal with any measurement/observation/indication of a signal of such kind of influence of gravity.

CZV: " We can read in so many papers published in so many important scientific journals about the extraordinary success of GR. "

Sorry, Cesar, the 1916 theory is logically incoherent and fails to agree with astronomical data unless one invents a whole new category of "thing" whose only purpose is to explain the mismatch ("dark matter").

If you think that counts as "extraordinary success", then I'd suggest reading up on scientific methodology for judging statistical significance.

Also, bear in mind that some in the GR community have been notoriously active at "cheerleading" over the years, in order to try to entice the best and brightest students into the subject, and give it a better future. I think the reasoning was probably that it's easier to attract talent and funding by claiming to have an "extraordinary" theory, than by admitting that the current system was dysfunctional junk and that we had no idea how to fix it.

Dear Eric

Well if you think that some of the most succesfull scientists in the history are just "cheerleading" without any proof of your statement, what can I say? I have no arguments for this statement...even Einstein?

CZV: " I start with a practical one: the accuracy of the Global Positioning System (GPS) depends on corrections from GR. According to GR a clock travelling in the weaker field of the orbit of a GPS satellite ticks more rapidly than a clock in the Earth. So GR corrections are essential for a more precise location. Thus when someone uses the GPS in his cell phone he is inadvertently testing the accuracy of GR. (See for instance Peter Edmonds). "

Naah.

Gravitational shifts are a consequence of Newtonian theory (John Michell, Journal of the Royal Society, 1784), and once you have gravitational shifts, gravitational time dilation becomes necessary to avoid logical breakdowns (Einstein, 1911). So the effect that you're talking about is expected regardless of whether we use SR&GR, or whether we use C19th Newtonian theory.

This is a classic example of pseudoscientific "cheerleading". It's a result that's presented as having significance, but whose actual significance (in the context of "GR vs NM") is practically zero.

CZV: " The knowledge of the gravitational lensing effect for instance, which allows a better knowledge about dark matter in the universe, is a consequence of GR predictions. "

The gravitational bending of light was described by Newton!

If you have gravitational bending of light, then you have gravitational lensing, by default. So while you're not technically wrong that it's a consequence of GR1916, it's misleading to make that statement implying that the effect provides significant support for GR, when the effect already existed in mainstream theory two hundred years earlier.

Science is damaged when scientists exaggerate the significance of evidential support. It leads to an inefficient misallocation of resources (with less honest practitioners succeeding at the expense of their more honest colleagues), encourages conspiracy theories, and when misdirections are uncovered, can lead to the general public losing faith in science and the veracity of scientists. We saw this happen with the "global warming" fiasco, where some "well-meaning" exaggeration encouraged politicians and oil companies to then claim that all climate change data was scientific fraud.

Scientists need to be honest. Even if it means occasionally missing out on grant money. Because the alternative is that entire branches of science can end up being corrupted or unfairly discredited.

Dear CZV,

Eric is not totally wrong... The time dilation at the first order, the one currently measured by instruments, is in fact derivable directly from the classic Lagrangian, the test of the gravitational time dilation by Vessot and Levine was done at the first order and it has been repeated in 2017. The classic Lagrangian energy, per unit of rest energy, is enough in order to determine the variation of the period of clocks with the current accuracy required by the GPS constellation. In any case the rest energy is a relativistic concept, E=mc2 .

"gravitational time dilation becomes necessary to avoid logical breakdowns"

it is a necessary concept in order to satisfy the least action principle (Lagrangian energy).

Dear all,

In every textbook of electromagnetism where the effects of retardation of the fields by the speed of light is described, one can find that relativistic speeds lead to the deformation of the electric field about the charge, making it radial and perpendicular to the motion.

This induces a magnetic field that is also radial and circular, and it auto-induces the charge as a very strong compression.

This makes instable particles to not decay so fast.

SRT cannot supersede this fact.

Also, charges cannot be accelerated any more by the means of electromagnetic fields if the electric field became radial and perpendicular to the motion.

SRT cannot supersede this other fact.

Hi

Dear Colleagues

Science is progressing over the years through careful analysis using one fundamental ingredient: the peer review mechanism! Peer reviewing of a theory, of a model, of the correction of theoretical and experimental results, of the conditions of experimentation made with strict scientific criteria, and so on. If someone questions current models, theories, or whatever, what they should do: make alternative scientific proposals and submit them to peer review in the most qualified scientific magazines possible. That's how it works. To say that if something is repeated over and over again, this repetition, --- solely ---, will not transform what is said into a truth, is right in part. But it is not correct in the scientific environment. In the scientific environment is the repetition of the experiments and methodological tests of theories and proposals that accomplish acceptance. Is this approach to theories or models or experimental and observational data by means of peer review, through careful methodological analysis, based on the scientific method, that makes certain scientific propositions more successful. One can say endlessly that Einstein's theory is worthless. Again, is just a repetition of words. Is a repetition of an opinion. It is not a scientifical aproach. It is meaningless, from the scientific point of view. This does not make the person's opinion acceptable in the scientific world, unless the person proves by theoretical calculations and/or experimental/ observational data that Einstein's theory has no value. And submit, not his opinion, not his insight, but his theory and/or experimental/observational data to peer review in skilled journals. This is what separates science from pseudo-science. Einstein's theories were heavily tested, questioned, proven in certain physical regimes, and contested in others. The beautiful article below, by Clifford Will, was written before the discovery of gravitational waves in 2016 (see also Centennial of General Relativity: A Celebration,

http://www.worldscientific.com/worldscibooks/10.1142/9690).

Is Eistein's theory perfect? Of course not! In the regime of strong gravity tests indicate that the theory would be incomplete. The presence of singularities in general relativity is an unresolved problem. Can quantization of spacetime solve this limitation of general relativity? We don`t know yet. But this is the beauty of science, search for answers, in a methodological way to questions that fuel our imagination. Science is not made up of believers --- if one imagines that a scientist accepts a theory only by sheer ideological belief, or epistemological belief, or philosophical belief. A scientist accepts a theory if this theory can provide answers, both theoretically and experimentally/observationally, in a logical-methodological (not just intuitive) way, to questions that populate our mind, in a proven way, after testing and further testing of theory through exhaustive repetition of calculations and experiments/observations, based on peer review. This is the key to acceptance of a theory by the scientific community.

Clifford M. Will said that:

The status of experimental tests of general relativity and of theoretical frameworks for analyzing them are reviewed and updated. Einstein's equivalence principle (EEP) is well supported by experiments such as the test of the Loránd Eötvös effect, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percentage using the Hulse-Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves

See article of Clifford M. Will

The Confrontation between General Relativity and Experiment

https://link.springer.com/article/10.12942/lrr-2014-4

https://arxiv.org/abs/1403.7377

Dear Cesar Zen Vasconcellos,

A celebration? The celebration of the dictatorship of the peer review mechanism, in order to maintain the jobs safe, and Einstein's theory undisputed?

"One can say endlessly that Einstein's theory is worthless. Again, is just a repetition of words. Is a repetition of an opinion. It is not a scientifical aproach. It is meaningless, from the scientific point of view."

How arrogant and pretentious are the handwaving replies from journals about the questioning of the SRT theory, of which the nowadays interpretation has been falsified over and over by scientists?

What do you have to answer, scientifically, to what Louis deBroglie wrote about SRT, with Einstein's approval, which I copied for you, and which seems to be very inconvenient for you?

"If someone questions current models, theories, or whatever, what they should do: make alternative scientific proposals and submit them to peer review in the most qualified scientific magazines possible. That's how it works."

How hypocrite is that "how it works"! Which peer reviewer would accept any alteration of Einstein's theory? You?

How credible would be someone who speaks of the celebration of Einstein's theories, about the thousands of supporters, who in fact were just poor students whoms brains have been twisted by their teachers, until they stopped questioning at all?

Are you even aware that there is a much better theory than GRT and SRT? How would you ever know, though, when knowing "how the system works"!

Dear CZV:

1 Peer review does not work well as a way of assessing discontinuous changes in theory.

That's simply not what it's designed for. Peer review is designed to offer a certification process for research in reasonably well established fields, where colleagues can check whether calculations are correct, that characterisations are not misleading and do not misrepresent the subject, that the citations indicate that the researcher has done sufficient background reading, and that the results are compatible with previous known and accepted results. It's optimised for incremental research ... which most research is.

If someone presents a scenario or an experimental outcome that is not compatible with previous known and accepted results, then it can be almost impossible for peer review to certify it, even if correct. We saw this with Stephen Hawking's initial presentation of the Hawking radiation effect: almost everyone of note believed that Hawking had to be wrong (because the result contradicted Einstein's general theory), and as a result, Hawking had to publish the result as a "Letter to Nature" instead, bypassing peer review. Peer review certifies that a submission is free from identifiable error, and in many cases, clashing with an established result is taken as a probable indication of error, meaning that the piece is automatically not capable of passing certification.

In the case of experimental results the "perception bias" filter can be even stronger, peer review usually cannot "certify" that the experiment actually produced the claimed result (because the reviewers weren't present when the experiment was carried out), it can only judge apparent credibility, and part of that assumed credibility is based on whether the final result is compatible with previous results. This causes problems when there is an emerging "false consensus" when previous experimenters have tailored their results to agree with past published results and created a critical mass of misleading data that prevents better data from being publishable. This infamously happened with lightspeed measurements in the early C20th.

2. Peer review is not science

Peer review is a social quality-control process ... but there are supposed to also be "creation science" journals that have their own version of peer review. Identifying peer review with science is like identifying typewriters with poetry. In the hard sciences, a mathematical or logical result is supposed to stand regardless of whether or not it's socially "popular". Math and logic and geometry are not supposed to be popularity contests, they are supposed to be about the search for fundamental truths.

Escalating peer review to a position of primacy downgrades physics from hard to soft science.

3. Failure is failure, is failure

When you say: " If someone questions current models, theories, or whatever, what they should do: make alternative scientific proposals and submit them to peer review ", you are wrong.

If I claim that Einstein's general theory is wrong ... if I can prove geometrically that the theory is logically inconsistent and therefore fundamentally flawed ... then I am under no obligation to provide you with an alternative replacement model that you find satisfactory! I am quite entitled to destroy your existing models and then walk away and leave you to try to sort out the resulting mess. As a scientist, you are obliged to accept a legitimate disproof, no matter how embarrassing the consequences might be.

Acknowledging the failure of a theory is not supposed to be contingent on our already having a politically-convenient drop-in replacement to hand. As scientists we are not supposed to hold back or suppress bad news about a theory until we have some good news to go with it ("Great News! X has been overturned and replaced by Y, which is even better!").

That would not be science but public relations management.

Dear

Peer reviewing is a mechanism for recognition of science! To separate science from pseudo-science...peer reviewing is the basis of the development of science. If you have a better theory than GR you should not be affraid to submit the theory to Phys Rev or Annals of Physics. Do that and them tell me what was the result. I would be glad to know.

"gravitational time dilation ... is a necessary concept in order to satisfy the least action principle (Lagrangian energy)."

Einstein's 1911 argument was cruder, based on pulse-counting. If we have a satellite in deep space emitting N1 pulses per second, and an Earthbound observer sees these pulses to be incoming at a greater rate N2 (due to the gravitational blueshift on the signal), then with the "read rate" greater than the "write rate", the mismatch should eventually result in the observer seeing pulses arriving before they are emitted! ... unless the Earth-observer's sense of what constitutes "a second" is different to that of the satellite's.

So Michell's 1784 gravity-shift result, combined with the C19th knowledge that light's frequency is proportional to its energy, makes gravitational time dilation pretty much compulsory in order to avoid logic going crazy. Einstein's 1911 paper presented the argument using Newtonian theory (since this was simpler than SR, and the argument was general and didn't care which exact equations we used). And, in 1911 Einstein hadn't yet constructed a general theory. So that's three reasons not to think of gtd as "belonging" to Einstein's 1916 theory.

CZV: " Well if you think that some of the most succesfull scientists in the history are just "cheerleading" without any proof of your statement, what can I say? "

I'd hope that you'd have sufficient knowledge of the community to recognise what I'm saying from your own personal experience without requiring additional proof. Remember back when some GR people were claiming that Gravity Probe A proved GR ... before they got told to shut up as it only validated the principle of equivalence, which was rather more general? ;D

In my experience, the most significant scientists in their field are the ones that are quite happy to talk about general relativity having problems ... these people are the ones who hope one day to participate in replacing GR with something better, and so they have a personal motivation to embrace any suggestions that GR may be suboptimal, because those cracks and defects are the starting points for designing what comes next.

By contrast, the physics people who know that they have no hope of ever contributing to the construction of a better theory ... the ones that, putting it brutally, just aren't as good at this stuff ... are the ones who tend to embrace the current system and insist that there's nothing wrong with it. They've invested in the status quo, and if it breaks down they'll have to re-educate themselves, and may be overtaken by brighter and younger students. They're the ones who do their best to argue that we don't need a new theory, because the existing one is just fine.

So ... Kip Thorne, cheerfully talks about the disagreement between GR and QM as being one of the greatest disasters in current physics – he's "first-division". He's actually discovered principles and developed paradigms. He's a proper theoretical physicist.

On the other hand, someone who turns up on a Horizon tv programme gushing about how GR is the gold standard and is amazing, and has passed every test with flying colours ... and when I google them, they seem to have never actually discovered anything ... they're second or third division. Those guys are on tv because they have a job title and give tv-friendly quotes. They may be successful career-wise, but don't seem to matter much in the larger scheme of things.

CZV: " I have no arguments for this statement...even Einstein? "

Einstein's on my team, not yours! :)

Once the general theory became a success, Einstein didn;t go around exaggerating how great it was – he went around telling people why he thought parts of it needed to be overhauled.

Einstein said that he admired Newton's determination to be his own greatest critic, and he appeared to be trying to emulate Newton in this respect.

Einstein said some witheringly brutal things about how bad parts of some of his own theories were. He described special relativity's spacetime as inherently defective, and he told Heisenberg that the special theory's basic causal definitions were "nonsense". He declared that general relativity wasn't to be taken seriously for black holes, he at one point asked someone why anyone would bother trying to get an exact solution to GR since it was such an ephemeral set of equations, and he spent much of the end of his life trying not to defend GR but to work out how to replace it with something better.

Where I disagree with Einstein's 1916 general theory is that I think that (with hindsight) it should have been a fully integrated single-layer theory, not something created by fusing flat-spacetime logic for inertial physics with curved-spacetime logic for gravitation, and hoping, optimistically, that the two sets of conflicting design philosophies wouldn't clash. It turns out that the two do clash, and the combination produces irreconcilable logical conflicts.

The only other person I've seen raising this sort of objection to GR1916 in public is ... Einstein himself. Einstein argued in 1950 that the approach that he'd taken to construct GR1916, with the general principle of relativity applied primarily to gravity and everything else dealt with by flat-spacetime SR ... was "indefensible". A general theory, argued Einstein, ought not to be assembled from "gravitational" and "nongravitational" components. The distinction was artificial, and a proper general theory needed to be built only from components that were demonstrably compatible with the GPoR from the outset. That's essentially my position too, I've just taken it a bit further.

Einstein didn't publish this in a peer-reviewed journal, but went direct to the public and put it in an article in Scientific American. Apparently he pretty much boycotted peer-reviewed journals towards the end, his position being that if he wanted to write an article setting out an argument or position, and was prepared to sign his name to it, that he shouldn't have a bunch of anonymous peer-reviewers deciding what he should and shouldn't be able to say. John Wheeler also apparently avoided peer-reviewed journals in his later career, preferring to write books where he could say what he wanted to without being censored by some anonymous committee.

CZV: " Peer reviewing is a mechanism for recognition of science! "

As is ResearchGate.

Peer review also put Galileio under house arrest, led to Newton initially abandoning natural philosophy in disgust after being called a fraud over his light-prism experiments, and allegedly led to the execution of Hippasus by the Pythagorean Brotherhood for the heresy of claiming that root two wasn't a rational number.

CZV: " To separate science from pseudo-science... "

Hawking radiation wasn't pseudo-science, but it was still initially too controversial to be published in a peer-reviewed journal.

CZV: " Peer reviewing is the basis of the development of science. "

You mean, as opposed to the people who actually do the work, like Newton, and Galileo, and Einstein, and Hawking? Isn't that like saying that the important people who advance Art are not those scruffy artist types, but the nice suit-wearing critics and gallery owners?

Peer review's "forte" is dealing with "baby-step" incremental advances in science. It's not so good at dealing with new ideas and concepts that require a significant revision of existing knowledge. Newton and Galileo both had significant problems with peer review. Galileo ended up under house arrest and forbidden to publish, Newton was so upset about being called a fraud over his prism experiments that he actually gave up physics for some years (before being persuaded back by Halley and friends, and going on to write Principia and Opticks).

Hawking radiation was arguably the biggest breakthrough in gravitational physics in the last half-century, and became accepted in spite of peer review. John Taylor allegedly told Nature that they shouldn't publish it.

Peer review has its uses in the development of existing theory, but when it comes to new theories, it can be one of the biggest obstacles to scientific progress.

CZV: " If you have a better theory than GR you should not be afraid to submit the theory to Phys Rev or Annals of Physics. Do that and them tell me what was the result. I would be glad to know. "

A paper on the suggested alternative system probably wouldn't be eligible for publication in either Phys Rev or Ann Phys, since both journals require results to be previously unpublished, and most of the results have already been described in a book. And I'm not sure that it's possible to describe an alternative system to a 100-year-old theory, in sufficient detail to address most of the immediate objections, and demonstrate to their satisfaction that the system really is apparently free from error, in the space of a single paper. The replacement theory has a much wider range of application than current GR, so it impacts on inertial physics, cosmology, Hawking radiation, measurement theory, topology, information theory, particle physics, acoustic metrics, thermodynamics, etc. Although it arguably has fewer components, the result is a bigger system than Einstein's, which means that there's more "alien" material for a peer reviewer to object to.

It's the same problem faced by Hawking in the 1970s, but on a larger scale: Once a topic is "known", people will publish papers on it, even if its only to object ... but how do you get the conversation started if peer review won't touch the subject with a bargepole, or refuses to accept that the subject even exists?

Perhaps the answer is ResearchGate. It might be fun to launch a scientific revolution without going via the journals (although I am still quite fond of Nature and C&QG)

Dear Eric,

"Einstein's 1911 argument was cruder, based on pulse-counting."

that paper was flawed in one part... there is a confusion between the doppler effect of the first order

and the time dilation.

Einstein supported since the beginning the fact that co-moving accelerated objects manifest a time dilation

in their comoving frame. Unfortunately this has never been demonstrated experimentally, in addition it can be demostrated that it is false.

Such confusion remained but was about to be wiped away by Schiff who lost an occasion in 1960's...

Time dilation has not a kinematic origin, but dynamical..only the action prinicple can account for it.

Dear Eric

Sorry, reserchgate is nice, funny but it is not peer reviewing ... as wikipedia... it is a place for free thinking... i like that...make me think in other grounds, despite some chaotic and non methodological paths... but, don't take it so serious... have fun... science is also a path for fun...

Dear all,

I asked my question because I wanted to have some novel idea and suggestion about my hypothetical account. I did not submit the manuscript to a journal, because I felt there is still something missing in my account. However, my idea has been to treat the problem just by a mathematical standpoint, forgetting for a while the possible feasible counterparts.

Dear Sydney,

We have to describe and quantify the physical step, that, according to our highly hypothetical account, might explain how the making of the macroscopic world from the microscopic erases the most of the coordinates, leaving just the one we observe... as if, once the gravity starts to influence its force in macroscopic structure, it would be able to breack the symmetry of the underlying quantum manifold...

Because it is difficult to build a quantum set encompassing gravity as a subset, I preferred to start with two, more manageable, sets that may somehow mathematically interact.

Dear Syndney, gotcha... the general idea is that one...

Dear Arturo

Recently I read a paper by Craig Hogan and Ohkyung Kwon*; The authors say: “Einstein’s classical theory of dynamical space and time— general relativity— is well known to be incompatible with principles of quantum mechanics that govern other forms of physical energy and information. This mismatch could be resolved if general relativity itself is actually an approximate description of a quantum system.” The authors introduce a new idea: quantum geometry, based on the idea that quantum units of space itself might be large enough to be studied directly. According to them, “space and time are statistical or “emergent” behaviors of a quantum system with many degrees of freedom, in the same way that sound waves in a gas are a collective behavior of many quanta. The quantum states of the geometrical system should not themselves resemble particles and waves of the familiar sort, which require a background space and time for their definition.” In other words, the assume correlated geometrical fluctuations in the same way we assume in QM quantum fluctuations. And as we assume that Classical Physics is an approximation of quantum mechanics, the authors assume that GR is an approximation to space-time fluctuations. The contact point for them to introduce this new idea was: sound waves (classical physics domain) in a gas are a collective behavior of many quanta (QM domain); could be that space and time (as defined in GR) are statistical or “emergent” behaviors of a quantum system with many degrees of freedom (at the quantum geometrical level)? *https://arxiv.org/pdf/1711.05514.pdf

Now returning back to your question. The word quantum in your question cannot be related to QM in general grounds (meaning that you are linking gravity and the other three forces).

The two most successful theoretical formulations in the description of nature are general relativity (GR), which accounts for gravity, --- and related events/phenomena, orbiting planets, collisions of galaxies, the dynamics and structure of the expanding universe, among many others ----, and (conventional) quantum mechanics (QM), which accounts for the physics of the remaining three forces, electromagnetism, the weak and nuclear (on its two levels) forces. There are many aspects to GR and quantum mechanics are fundamentally different theories: they are based on different formulations, they have different scopes, they assume different physical fields, they represent different mathematical/physical approaches, they are based in different assumptions, their physical validity correspond to very different physical scales, they assume different dynamical approaches, they are based on different symmetry/conservation-laws arguments, among other aspects.

It is not just a matter of scientific terminology. Both theories correspond to genuinely incompatible descriptions of reality. But their scopes are complementary. Remember, when you talk about gravity, you are talking about a force, and when you talk about quantum mechanics, you are talking about a theory that comprises the phenomena related to the other three forces of nature. So, unless you have a better theory for gravity that GR, let’s continue to discuss GR x QM.

Let me draw attention to practical aspects that differentiate the two formulations. In RG, physical events, immersed in the background of a continuous space-time, non-disruptive, --- except in the first instants of the Universe and in the surroundings of very large masses originating space-time singularities ---, are described by a deterministic physical formulation, at least locally, meaning that every case matches up to a specific local effect. On the other hand, QM is non-deterministic, and in QM probability plays the central role in the measurement process when wave functions collapse. If someone tries to re-scale the two theories, so that they can cover astrophysical / astronomical phenomena and simultaneously quantum phenomena, GR, when scaled down to typical quantum mechanical scales, gives nonsensical answers; When you scale up QM to describe phenomena typically described by GR, the same occurs, that is, QM presents absolutely unacceptable results in this physical domain.

So, of course we are talking about our present knowledge of QM and GR.

When you talk about sets and subsets, in physics I assume that you are thinking in a kind of mathematical description that somehow relates the sets and subsets. Now, what is the content of the sets and subsets? In general, when you talk about QM you are talking about elements contained in sets and subsets. Those elements can be observables, quantum waves, and so on. And if you talk about sets and subsets related to physical problems, you have to talk about correlations, interactions, algebra of elements, representations of some group theory, symmetries, conservation laws and so on in order to make the description of physical reality consistent.

Take for instance, as an example, the irreducible representations of SO(3) which are appropriate for describing the degeneracies of states of quantum mechanical systems which have rotational symmetry in three dimensions. According to the Stern–Gerlach experiment, electrons are endowed with spin internal degree of freedom which has the symmetry properties of angular momentum. The two spin states on the other hand are inconsistent with the dimensionality of the irreducible representations of SO(3), so another group, SU(2), --- different from the previous one, with a different algebraic structure ---, must be used to describe these states.

Why I am talking about these two group theories? Because in order to establish sets and subsets of elements, of observables and so on, in a consistent way, you need to take into account the algebraic relation between physical sets of observables, of the corresponding wave fuctions, of generators of physical states and many other ingredients as I said before. If the algebraic formulations involving for intance gravity and quarks and gluons are not the same, --- and they are not indeed ---, you cannot just collect them and separate them in sets and subsets, you need some organizing principle to make your formulation consistent.

SU(2) by the way may be seen as an subset, --- in the sense of the algebra of its elements and generators ---, of a more complete algebra, SU(n). Now, according to our present knowledge, the algebra associated to elements and generators of transformations of the fundamental nuclear, electromagnetic and weak forces are incompatible with any algebraic definition in GR.

Ok. Thanks

Dear Cesar,

QM and GR cannot be described by the sets of the Zermelo-Fraenkel theory, in particular because the latter postulate a set of infinite elements and is unable to describe the most general set that encompasses the others. The trick we used is to take into account two subsets, whose points in common are just the mathematical properties of commutativity and non-commutativity, and to leave apart a possible larger, untreatable set that encompasses the both of them. We know that we have just the mathematical part, and not the physical counterpart, otherwise we were going to send the manuscript to Nature, instead of preprinting it on RG. However, if we, differently from you, consider the Universe as a whole which encompasses both QM and GR (just at different levels of observation!), we are making the very first step. We need, I think, a (very complex) gauge theory where the symmetries broken by quantum non-commutativity are restored by a gauge field (i.e., the gravity), that allows commutativity in the macroscopic world. ...or something like that... Ours is just a pale hint of a possibility, but I am delighted that you spent your time reading about quantum geometry... This means that, in a remote part of your brain, my universe of discourse activated a small flame... This was my goal.

Hi Arturo

Ok. thanks. I remember below a publication on a gauge approach to GR, but without coupling gravity with the weak, strong and electromagnetic fields.

D. Grensing and G. Grensing

Phys. Rev. D 28, 286 – Published 15 July 1983

It is shown that a consistent gauging of the Poincaré group is capable of including Einstein's general relativity. This statement holds for matter particles of arbitrary spin, provided the nontrivial part of the vierbein is taken as the fundamental gravitational field, thus giving rise to a known modification of the original theory. Since the gauge approach implies that gravitation is an ordinary field theory over flat space, the standard prescriptions for calculating the asymmetric momentum tensor of both matter and gravitation are available. Applying Belinfante's flat-space symmetrization procedure to the latter, we prove that the symmetrization of the asymmetric matter tensor just gives the dynamically defined symmetric matter tensor, whereas the symmetrization of the asymmetric gravitational momentum tensor leads to another version of the field equations that reveals a deep analogy to the equations of electrodynamics. Furthermore a method is developed that admits an unambiguous calculation of gauge-fixing conditions from a given gauge-breaking term. Besides the harmonic gauge, which can be reproduced by means of this method, new gauge-fixing conditions for local translations and local Lorentz transformations are obtained. These gauge-fixing techniques, as well as the symmetrization procedure, may equally be generalized to the case of nonvanishing torsion.

Continuing the discussion about non-commutatity and spacetime, see

https://arxiv.org/pdf/1611.07830.pdf

and

https://arxiv.org/pdf/1611.07842.pdf

More to the point, there is the issue of inflation in non-commutative space time, introduced in

https://arxiv.org/pdf/1506.04049.pdf

Dear Jim, thanks for the very useful insights!

Dear Cesar, very interesting paper, I did not know about that.

Other papers that describe such issues are quoted in our manuscript.

Interesting and valuable question with very rich and insightful comments and links.

Dear Jim,

gotcha!

I write here, and not as usually by mail, so that also Cesar could read my novel idea.

If we remove the controversial gravity from our manuscript, we might focus on the mathematical unification of commutative and non-commutative operations. We might use the dagger cathegory, a dagger symmetric monoidal category and dagger compact closed categories... Therefore, we could remove the gravity paragraph, and to add a novel paragraph that talks about such a mathematical treatment and how to use it in order to better describe our commutative/noncommutative groupoid...

Dear Arturo

Concerning your answer related to a previous message involving DeBroglie view of Lorentz invariance, "... d'après Einstein, de la transformation de Lorentz. La première, en effet, était censée être une contraction réelle provoquée par le mouvement absolu du corps dans l'éther,..." of course you are completely right in your statement since "l'ether" was proven to be a meaningless idea...as the idea of "mouvement absolu du corps..."

Dear Sydney, I'm sorry, but you do not take into account that bosons do not obey the Fermi principle, therefore they do not need to occupy a different volume of space.

Dear Sidney

Conservation of energy in the Universe has to do with the continuous time translation symmetry of the laws of physics. As a result the expectation value of the Hamiltonian H of a physical system, the energy E, is a constant.

Conservation of energy is the consequence of global time translation invariance. Under certain circumstances, when spacetime curvature can be neglected, this is true. When spacetime curvature can't be neglected, this isn't true.

Scalars and vectors-as particles-have been discovered and can be described as quanta of the corresponding fields.

That Newtonian gravity isn't consistent with a finite speed of light isn't surprising; it is a consistent approximation to general relativity, that does describe spacetime curvature and how classical matter affects and is affected by it, when speeds become comparable to the speed of light.

How quantum matter affects spacetime curvature isn't known in full generality.

However gravity-curved spacetime geometry-is, still, a classical notion and how it can be described as the classical limit of spacetime geometry when quantum effects are taken into account isn't known.

Noncommutative geometry is classical, inasmuch as the parameter(s) that describe it aren't related to Planck's constant.

in my work (published here on RG too) I have the results of unification RT and QT; they are devastatingly for the big-bang theory!

Einstein told Heisenberg that it was quite wrong to attempt to base QM on only observable variables (as Einstein had done with special relativity), because in reality pure observables alone should not define a theory, rather, the theory should define what is and is not observable. Heisenberg credited this conversation with inspiring the uncertainty principle named after him.

The problem we face with reconciling GR with QM is that this "quite wrong" principle that's present in SR is then inherited by Einstein's general theory. So QM and current GR are based on some fundamentally incompatible concepts and core definitions. This incompatibility is not about "classical vs quantum", because it seems that it is possible to build a classical theory that generates QM-style principles and behaviours ... it's just that this is not the path that we took.

Kh. Namsrai's paper explores what we end up with if we construct a classical geometry around the idea that it has to be an emergent result of QM statistics:

• https://www.researchgate.net/publication/225431311_Space-time_structure_near_particles_and_its_influence_on_particle_behavior

The resulting QM-compatible classical model diverges from current SR/GR. With Namsrai's approach, we have to assign distortion fields to all particles with mass, and these fields also have to be seen to distort when the particles move wrt the observer. For symmetry, the observer then also has to be particulate, so current classical relativistic approaches that assume purely "mathematical" observers end up being invalidated.

We end up with a "GR-style" curved-spacetime description of inertial physics that implements the PoR differently to special relativity, and "scales up" to become a general theory of relativity that's different to Einstein's.

If we accept this chain of arguments, the reason why GR and QM currently refuse to mesh is not because of any fundamental incompatibility between classical and quantum approaches, it's because our current classical theory is naive. For someone holding this point of view, the way to an integrated theory of quantum gravity is not to create a further layer of theory that attempts to embed both QM and GR1916 as perfect subsets, it's instead to redesign general relativity on more solid foundations, after which it should mesh with QM naturally.

I applaud people's enthusiasm for mapping out the hypothetical rules that would have to apply to a theoretical superset of GR1916 and QM, but I also think it's important to point out that if current GR is "bad", it may be impossible on principle to create a valid superset theory that incorporates both it and QM. If people still want to do the work then that's fine ... but the decision has to be an informed one, and the authors need to be warned that they might be trying to work towards solving a problem that actually has no possible solution.

< we might focus on the mathematical unification of commutative and non-commutative operations. > apropos noncummutatve quantum vs. commutative relativity: string theory is based on non-standard analyse... for instance: axb=-bxa. generalizing: distributions theory begins with: integral(u`v)=-integral(uv`)

Dear Paul, recent published studies diffusely talk about the noncommutativity of string theory. ...I read it a few days ago on a good physical journal, but I do not remember which one...

dear Arturo, is it meant like a*b=-b*a or more restrictive?

ps. as physicists always adjust the string theory I do not agree with... I have my own opinion by using distributions theory- more: I have the results of unifying RT and QT (as I said) without using strings

GR doesn't ``emerge'' from a QFT of particles, because the former's effects are controlled by Newton's constant, whereas the latter's effects are controlled by Planck's constant and these are independent constants.

Closed strings can describe gravitational effects and the new constant they introduce is the string tension. How to sum over string configurations, that don't satisfy the classical equations of motion isn't known, however, in full generality.

That spacetime curvature leads to effects that can be described in terms of objects that don't commute simply expresses the fact that parallel transport of a vector around a closed curve, on a curved manifold doesn't lead to the same vector.

Something, mathematically, similar, occurs with a particle that is charged and moves in the presence of a flux-the simplest case is that of an electric charge in a magnetic field and extended objects have been found to carry more complicated charges, that, also, couple to fluxes and, thus, lead to the relevance of non-commutative geometry for describing them.

But these fluxes are, still, ``classical'', since it's not known how to sample configurations of such objects, that don't satisfy the classical equations of motion.

The phase space of a quantum particle can, indeed, be described, mathematically, in terms similar to those of a charged particle in a magnetic flux-where the flux is equal to Planck's constant. But this is its phase space, not its spacetime.

Dear Stam,

Our (mathematical) hypothesis is that we could go from quantum phase spaces to relativistic spacetime, once the Newton's constant, trascurable at the quantum microscopic level, starts to exerts its influence in the macroscopic world. Therefore, spacetime becomes just the choice of one of the countless coordinates underlying the quantum quantum dynamics' manifold. We are not able to describe all the required conservation laws during the passage, but, I think, this approach could be worth to be pursued...

On the other side, an unification is somehow required, in a positivistic sense, otherwise we have two different realities that describe the some thing, i.e., our universe. And we cannot simply reduce ourselves to say that they are incompatible... something, at least at a theoretical level, must be tried...

as Sydney said < I only know some physic laws, constants and derived equations that are related to the general properties of our universe. > maths is totally true merely when abstractions are made.

Arturo> The relation between phase space and spacetime is quite subtle. When gravitational effects can be neglected, while phase space becomes a non-commutative manifold, when quantum effects are relevant, spacetime does not.

When gravitational and quantum effects are both relevant, it isn't known what happens, in general. For certain cases of extremal black hole spacetimes, it is known that the near horizon geometry can be described consistently when the probes are quantum objects and, in that case, the non-commtativity of the phase space of the probe is related to the non-commutativity of the spacetime, since the probe is charged under the fluxes that define the degrees of freedom, that describe the spacetime, in which the quantum probe moves.

Classical gravity, already, is defined by the property that coordinates aren't physical quantities and the latter should be invariant under general coordinate transformations.

The universe isn't filled with ``mathematical'' fields. And if there were a non-zero vector field present, it would be immediately obvious, since it would define a preferred direction-which isn't measured.

Dear Stam,

"if there were a non-zero vector field present, it would be immediately obvious, since it would define a preferred direction-which isn't measured."

I think that you refer to the Michelson & Morley Experiment (MMX).

In that case, you are right, but the mainstream interpretation is wrong.

The MMX only proved that the hypothesis that light is carried by the aether and that there is a global ether for the propagation of light and that the Earth is moving wrt it, is wrong.

All the other possibilities remain open, including the case where the velocity of the aether w.r.t. the apparatus was to be considered zero.

On the other hand, you say that there is a space-time. However, Special Relativity is about the communication signals between inertial reference frames only, and the transformations express the retardation of the signals.

When electromagentic waves are used instead, Oleg Jefimenko has proven that the results can differ from the SR results.

Hence, the transformations are not universal.

So, there is no space-time because it cannot be defined universally.

Dear all, Hi!

An experimental way to demonstrate quantum gravity (that is the core of our idea) has been proposed: Article A Spin Entanglement Witness for Quantum Gravity

Article Gravitationally Induced Entanglement between Two Massive Par...

Unfortunately such effects don't have anything to do with quantum properties of gravity-but with quantum properties of matter. The gravitational effects remain classical and this feature is not affected by the quantum properties of matter. That's why these experiments don't have anything to say about quantum gravity.

“…An experimental way to demonstrate quantum gravity (that is the core of our idea) has been proposed:..”

the proposed experiment seems as rather difficult for be made by a few reasons; first of all because of extreme weakness of Gravity force, really some serious enough problems can appear at selection of the gravity effect on an inevitable background/noise, besides here is a problem of calibration.

Next, what is essential in this case also, here is evidently possible only interactions of entangled masses, i.e. particles and many-particles systems, i.e. atoms with Earth’s field, which have too large masses and so a selection of single interactions of the masses with single gravitons seems rather difficult also.

When much more simple experiment, where the quantum nature of Gravity can be observed, where gravitational interaction of the Earth’s field happens with lightest particles, i.e. photons, was suggested yet in 2007, see https://www.researchgate.net/publication/245583444_On_the_photon_spectrums_of_some_monochromatic_beams_in_Earth_gravitation_field arXiv:0707.4657v2, more detailed version see https://www.researchgate.net/publication/215526868_The_informational_model_-_possible_tests arXiv:0706.3979v3; at least the section 2.1.2. “Monochromatic photon beam distortion”.

To make the experiment it would be enough to make a vertical hole having length 300-500 m and to place in the hole the additional arm in any existent interferometers that were built in first attempts to detect the gravitational waves and which aren’t practically used in physics; thus the rather probable observation of the quantum gravity will cost no more then a few tens of $1000 000.

Cheers

No way, the slight local space distortion posed by GR, inefective over small distances involved in QM. It may be some speculation, but thats about it. Remember always gravity is a really weak force, compared to electromagnetic.In case of doubt do some quantum experiments in those space ships where the astronauts just float around. There may already be some?

That does not mean there is no connection. The gravitational potential can phase shift a horizontal beam of neutrons.(neutron interferometry) The gravitational potential acts the same as any other potential with respect to the quantum, but again, very weak.

All this is different from those who would want to quantize gravity itelf

The quanta carried by gravitational waves, or graviton?

no evidence yet.

To answer the original question, I do think that it is possible that the gravitational field, which is the field of space-time, could be the bridge between the commutative nature of large-scale relativistic interactions and the non-commutative nature of quantum interactions.

The problem we face is that the gravitational field is itself a large-scale phenomenon, while quantum interactions are microscopic. But there is something interesting that relates them both: The field of space-time cannot be viewed or measured from the outside. We can only measure it from inside space-time.

In Lee Smolin's book, Three Roads to Quantum Gravity, he writes:

"Among the things we had to struggle with were the implications of the fact that the observer in quantum cosmology is inside the universe. The problem is that in all the usual interpretations of quantum theory the observer is assumed to be outside the system. That cannot be so in cosmology. This is our principle and, as I've em­phasized before, this is the whole point. If we do not take it into account, whatever we may do is not relevant to a real theory of cosmology….

"What is needed is an interpretation of the states of quantum theory that allows the observer to be part of the quantum system." (pp. 40-42)

However, contrary to what Smolin says, using the approach of looking at quantum interactions as if we are outside observers doesn't work. It creates real problems because, as soon as we try to observe, we alter the quantum states that we are trying to measure. In other words, there really is no valid outsider's perspective for what is happening to quantum states, and this represents the underlying issue beneath "the measurement problem."

This suggests the possibility that, as Smolin says, what we need is an insider's perspective on quantum mechanics, rather than trying to always reduce it down to an outsider's point of view.

The lesson learned from cosmology might help us find the bridge to a new understanding of quantum mechanics.

Just another thought that is worth considering.

Doug.