Dear Stefano,

The electron zitterbewegung energy or De Broglie matter wave energy is in fact the energy carried by the gravitomagnetic field of an electron, since the gravitational field along with the associated intrinsic magnetic field of an electron are actually two sides of one coin. When an electron annihilates with anti-electron, the rest energy of the electron becomes the kinetic energy of a photon, while the gravitomagnetic field energy of the electron becomes the electromagnetic field energy of a photon.

Detailed discussions are in section 7 of this paper:

Article Functions of the Gravitational Potential

Space time is one thing the EM field runs on it and interact with it but is something else. The value of the curvature depends also on the EM fields, but only because of their energy-momentum content.

Gravitational attraction exists between energies. Total energy of Fermion and antifermion is same as the total energy of photons it creates after annihilation. After annihilation the charge between two leptons will disappear and the gravitational attraction will exist between created photon and its antiparticle which is also photon. This is what happens with the conventional photons at present epoch.

I have a theory where a grand father photon called Saviton can exist at Planck energy level at the beginning of the universe. It has energy of the order 10^19 GeV. This is a massless kinetic energy from which strong force and electroweak force has not separated. When two Savitons collide at speed of light, they can annihilate into a state of energy which is perfectly motionless and the gravitational attraction between them will simply disappear. This marks the unification of gravity with rest of the forces. Following is the link to the article.

@Guoliang Liu. It appears that your theory does not allow gravitational attraction between two created photons. Is that correct?

Article Periodic quantum gravity and cosmology

Gravitational attraction between photons doesn't exist, since not even the gravitational attraction between matter and photons exists.

Article Gravitation, photons, clocks

Stefano ~

Why do you say "...not even the gravitational attraction between matter and photons exists"?

Isn't the well-known bending of light near a large mass direct experimental evidence of the gravitational attraction between matter and photons?

Eric it is not "gravitational attraction", it is something else but not gravitational attraction

Aleksei, there are much more authoritative guides than you, WHEELER and OKUN. And an experiment to confirm it Gravity probe A. If you admit the attraction of matter towards the photons you have to admit gravitational potential energy of photons, and I showed it doesn't exist.

Article THE GRAVITATIONAL POTENTIAL ENERGY OF PHOTONS IS AGAINST THE...

Whose invention??? It is not gravitational attraction. It is only space-time curvature which does not "attract" photons like massive objects. They just follow null geodesics.

Aleksei don't worry I understood OKUN, TELEGDI, WHEELER and others correctly and for THEM  gravitational attraction of photons or energy gain/loss of photons exiting a gravitational potential well, is a mistake.

Dear Aleksei,

electromagnetic quanta follow null geodesics, null because light is not affected by time.

The paper you refer to is from 1989. Okun himself in 1999 supported by Others changed probably his mind, excluding any gravitational mass of photons or gravitational attraction, what Feynman said about the gravitational potential energy of photons is false.

There is no energy Exchange between the photon and the generator of the gravitational field. It is not like two massive object attracting eachother which change the configuration of their energies.

Photons travel through space time without any variation of their energy unless they are absorbed in a quantum process with electrons, only the direction of the momentum can be variated by the space time.

Light deflection was  explained in GRT by Einstein as curvature of the space time only, time like part and space like part. They account for double the deflection estimated in the unappropriate way using Newton's equations and assuming that light posesses a gravitational mass.

For me gravity or gravitation is related to force between two masses, everything comes from geometrodynamics, space-time curvature, and the behaviour of light is very different from a relativistic particle possessing a not null mass. Light has "ultrarelativistic" properties and does not have mass when it crosses space-time.

"Right after the annihilation of two leptons what happens to their gravitational field ?"

Nothing happens to gravitational field. The energy is conserved, so is gravitation, no matter what happened to "mass".  Aleksei Bykov is right about that.

Stefano, BTW, I don't think that your statement addressed to Aleksey, "...there are much more authoritative guides than you, WHEELER and OKUN. ..."  belongs to a scientific discussion. This is not a religious dispute with pounding your fist on a table with references to Bible, and the personal attack like yours "more authoritative guides than you"   does not sit well with good science. Besides, so far I've seen no tangible proof  that  YOU are to any degree an "authoritative guide" on the subject.

@ Kaplan.

I know energy is conserved, this is not the point. It is not the argument of the question.

It's enough to see the publications regarding "authoritative guides" .

Regards

@Aleksey you said: "It is your claim. I asked you to prove it and show the difference between phtons and, for instance, electrons. You are just repeating what you said." 

I ask:

"gravitational potential energy " implies energy gain or loss of energy in a gravitational field??

Do you agree???

Electrons are massive and they interact with other gravitational bodies and losing gaining their energy. They are like any other massive object, with a gravitational potential energy with some relativistic corrections according to their energy.

Do you agree??

Do electrons follow null geodesics??? I don't think so

And the more energy/speed they get the less they behave like light.

To Affirm that Photons lose/gain energy in a gravitational field, is the same as affirming the existance of gravitational potential energy of photons.

Do you agree???

@Aleksey,

"No. I do not agree. There is no "potenrial energy" in general realtivity (with exceptions mentioned earlier) at all"

Aleksey we are talking about physics and measurable quantities. Schwarzschild solutions too is GRT and is in term of Newton potentials, what are you talking about??? Don't worry it is clear to me that if I account for the geometrodynamics the Newton laws are included.

I SAID  "Do electrons follow null geodesics??? I don't think so" YOU SAID " No of course. They follow not time-leke geodesics. It is first thing you should know if you study general relativity."

So you answered to yourself,  photons don't behave like electrons.

Anyway I make a summary :

Everybody here affirm that the process is clear and what comes out are two photons, and nothing else, since momenta conservation say that,

I  doubt that the space-time curvature of two photons is equivalent to the one formed by two leptons even right after the process. Since annihilation is the most exoenergetic process known , I have doubts that gravitational waves don't come out, together with photons, even though their contribution is negligible respect to the energies at stake.

Stefano ~

It’s quite reasonable to suppose that in any interaction of elementary particles (eg. in your example two leptons transforming into photons), gravitons are also involved. Indeed, that would seem very likely. Because of the extreme weakness of gravitation in these contexts, quantum mechanics is safe to ignore gravitation completely in these contexts. In principle, very tiny effects should be there, in the form of energy and momentum transfer to and from the gravitational field (and also angular momentum transfer, since gravitons have spin). At the classical level of GR, this could be viewed as energy-momentum transfer between curvature of spacetime and the fields interacting with each other in that spacetime. I trust that this is a reasonable interpretation of your question. However, in the absence a unified theory that incorporates both GR and QM in a consistent way, there would seem to be no quantitative answer. The effect would be virtually insignificant anyway, but in principle it should be there.

The process of annihilation is not clear enough for me. The gravity field of a single photon is unknown for me. The metric tensor (solution of General Relativity) before and after the annihilation shall be continuous - it is the Creator's sense of beauty. So, to ensure that everything is in best order just add the Dark Matter in the manner described in my book, see below:

Einstein’s gravitational theory is a ‘classical’ field theory, while a ‘photon’ is a ‘quantum’ of the electromagnetic field. We are dealing here with two fundamentally very different kinds of physical theory. Their reconciliation in a fully unified theory remains unknown. The original question involves a mixing of currently incompatible concepts, and leads to confusions and misunderstandings – as this discussion thread has revealed.

Stefano has said “For me gravity or gravitation is related to force between two masses”. That's a thoroughly Newtonian view of gravitation! The Einsteinian view is very different. A photon has no restmass, but we can’t jump to the conclusion that it doesn’t affect curvature, for the following reasons:

The field equations of general relativity stipulate that all energy-momentum produces curvature. This includes the energy-momentum of electromagnetism. Electromagnetism is, according to QED, the field whose associated particles are photons. So we are led to a contradiction if we say that photons have no effect on curvature.

The source of the confusion here is this: according to general relativity all ‘test particles’ are affected by curvature in the same way, whether or not their restmass is zero – their trajectories are geodesics. That is the ‘geodesic hypothesis’. The geodesic hypothesis applies to ‘test particles’, which are particles whose own gravitational field (ie, whose contribution to curvature) is taken by definition to be insignificant. The concept of a 'test particle' is a convenient idealization, nothing more. In the ‘real world’ there are no such ‘test particles’ – everything that carries energy-momentum contributes to curvature.

Eric,

“The geodesic hypothesis applies to ‘test particles’, which are particles whose own gravitational field (ie, whose contribution to curvature) is taken by definition to be insignificant. The concept of a 'test particle' is a convenient idealization, nothing more.”

It’s presumed that, for the purpose of evaluating models, test particles do not produce significant gravitational effects. However, in practice discrete elementary particles of any mass have never been shown to produce significant gravitational effects – no presumption is required. When the concept is applied to massive objects such as stars within a galaxy the model can break down since, collectively, billions of stars within the discs of galaxies do produce significant self-gravitating effects.

When considering the collective gravitational effects of photons, for example, it would seem that luminous masses such as the Sun should produce a radiating gravitational field – as a result their gravitational properties should be substantially different from, say, a cold neutron star of 1 Solar mass. Has any such distinction ever been established to substantiate the idea that discrete particles do produce a gravitating field?

Charles, that's true if it's assumed that discrete photons produce gravitational effects - that zero rest mass particles have gravitational mass.  I'm asking about observational evidence supporting that assumption...

Actually, I suspect that most of the stellar mass lost during a star's lifetime is the rest mass of mostly protons and electrons ejected in the stellar wind...

I realize there's strong theoretical bases for the assumption regarding photons.

Charles, I agree - my question is whether photons produce any significant gravitational effects - even collectively...

- which is why I was questioning Eric's comment from 6 days ago (~ Oct 3, 2014).

"Absence of Evidence Is not Evidence of Absence"

Thanks all.

Sorry I have no real comprehension of (or appreciation for) the math. In my view, math can explain, but it cannot cause, observed effects. That math can precisely explain observed effects does not ensure that it properly represents all contributing factors or effects.

However, if discrete particles are gravitating (producing gravitational effects) presumably by virtue of the curvature of spacetime they cause, and that curvature persists after their energy is annihilated, then there can be no direct causal relationship between local mass-energy density and local gravitational effects.

As I understand, it’s been determined experimentally that the formation of massive objects (such as the Sun) is not initiated by gravitational interactions at all. Rather, it is the attraction of EM charge interactions among particles that initiates the process of accretion. Only when some sufficient mass locally accumulates do the effects of gravitation dominate in producing greater local mass accumulation.

This might indicate that, unlike the 'other' quantum 'force' interactions, gravitation is not strictly a particle interaction at all. It might suggest that gravitation required some discrete, physical property of spacetime. If it was the general action of localizing material mass-energy that curved spacetime then even the process of condensing matter through EM charge interactions would cause gravitational interactions to emerge.

While accretion obviously condenses material mass-energy, it also produces an equal, opposite reaction: the extraction of material mass-energy from disperse spacetime - creating a boundary condition between condensed and dispersed mass-energy states. Perhaps it is the interaction of this boundary condition that actually produces what we observe to be gravitational effects.

In this view the early, homogeneous-energy universe would not have produced actual gravitational effects (localized interactions) - gravitation would not have emerged until perhaps the recombination epoch...

@ Aleksei,

thanks for the "Stefano Quattriny hypothesys".

Einstein neglected the contribution of Radiant energy, he wrote it down clearly in his book. I don't think he did it only because it was actually negligible as a hypothetical real contribute, but because he wasn't sure he could really account for it in the energy-momentum equations.

Photons do not interact energetically with the space-time, or rather no real energy gain or loss of photons exists with the GR field or with the space time itself. It is  only an apparent effect in a gravitational field , and this is what is affirmed by the GRT as written also in the article of OKUN.

it is quite difficult to admit that radiation in itself can be a source of curvature. It is a source of curvature only when it is quantistically absorbed by quarks or leptons, then it comes to be ordinary matter or tied energy for sure source of curvature. 

No experiment has been performed to demonstrate that light is "source" of curvature. So far being the light massless, being clear that it does not Exchange energy with the space time, having the light the possibility to be acquired in completely different places, if the wave packet is broken, by definition cannot be a source of curvature. 

The stress energy tensor which is local, in such situation of wave packet division could not be defined, because the collapse of the wave function can occur in completely different places, such that the position of the beam "a priori"  is not definite.

@ Charles,

"because there is no curvature in special relativity"

In fact we always have to refer to General relativity, that is why the vision of annihilation fo the particles in SR is partial and approximated. In General relativity the particles themselves curve the space time, the flat space time does not  exist, it is an approximation which is confortable to make faster but less accurate calculations.

@Charles

"Stephano, Okun says nothing about this topic."

which topic??

OKUN page 1048 physics Uspekhi.

"Einstein put forward the idea that the energy is not

only the source of inertia, but also the source of gravitation.

He used the heuristic argument: ``If there is a mass, there is an

energy, and vice versa''. As he realized later, this ``vice versa''

was not so correct as the direct statement was (a photon

possesses energy, whereas its mass equals zero). Identifying

the energy and mass, he calculated the energy loss of a photon

moving in the vertical direction in the gravitational field of the

Earth, as discussed above. Taking advantage of the same

heuristic principle, he also determined the deviation of a ray

of light by the Sun that was half the correct deviation.

Subsequently, in the framework of GR, Einstein found this

missing factor of two [3 ± 5]. The correct formula was verified

experimentally.

OKUN

"Their authors proceed from the implicit supposition that a

massless photon is similar to a conventional massive non-

relativistic particle, call the photon energy E divided by the

speed of light squared c2 the photon mass, and consider the

`photon potential energy' in the gravitational field"

Charles, we are talking about physics not math.

Aleksei, sorry but I'm talking about photon energy loss or gain and if there is loss or gain of energy it is with space-time or gravitational field. ANd in GRT or Physics, space-time does not change the energy of photons. If you don't understand that I'm sorry, it is your problem

"Frequently, such a

rigorous mathematical description is accompanied by non-

strict verbal representations of a photon that loses its energy

when it `gets out' of the gravitational potential well.

Even some classical textbooks and monographs  make use

of a similar `visual phraseology'. The experts on GR do not

pay attention to it Ð for them, this is merely a tribute to the

tradition of scientific popularization."

If it's presumed for a moment that (in the context of some theory) electrons and positrons locally curve (contract) spacetime by virtue of their locally condensed energies, that if those two particles annihilate one another - dispersing that energy - it must follow that the once curved spacetime could no longer be curved. The disposition of that curvature must depend on the theory of quantum gravity being applied...

Aleksei - I can't tell who your comment is directed to. Also, you might clarify what you mean by "... After you understand it, you will now, why potential energy is good notion for non-relativstica partciles and bad for non-relativistic ones, when coordinate energy (covariant "time" compoment of 4-momentum) is stirctly conserved in BOTH cases."

It seems to me you only mention ONE case... There are also so many spelling and grammatical difficulties that understanding the intent of your comment is very difficult. However, you incorrectly reference section 88 in chapter 10 ("Particle in a Gravitational Field") of "THE CLASSICAL THEORY OF FIELDS". I don't understand how that discussion applies to discrete particles' producing gravitational effects, if that's what you're intending...

@Aleksei,

"Also you should understand, that Okun s considerig one perticular case, where actual exchange between matter and gravity is totally forbidden by handling gravity as a constant external field", what are you talking about??? It is the GRT case...it is very clear Aleksei  E=pco is conserved where  co is the local speed of light. The actual frequency of the photon stays the same, the momentum varies according to the local speed of ligth such that pco is constant. The Redshift is only an apparent phenomenon there is no energy loss. If you don't understand this what else can I do.

Charles, I know what  you are talking about. But if light does not Exchange energy with the space-time doesn't it in anyway. 

I'm aware about the difference about geometry acting on photons and photons acting on geometry, I know that Okun is interested in how Geometry acts on photons, how curvature acts on photons.

Curvature acts on photons for sure, otherwise light deflection would not occur, but without energy exchange. The energy Exchange is anyway NULL. Only quantum mechanics and doppler effect can vary the energy of photons in a "real way" not apparent.

When wondering about energy exchange we need to think very carefully about what we actually mean by “energy” in modern physics. Even in special relativity energy is part of a vector and is consequently dependent on the choice of reference system (choice of “inertial frame”). In curved spacetime (ie, in gravitational theory) energy density is part of a tensor and is therefore dependent on the choice of coordinate system – it becomes a very elusive concept. When thinking of the curvature produced by “photons” we should be thinking of Einstein’s gravitational equations with the electromagnetic energy-momentum tensor on the right-hand side. Because of the Bianchi identity the total electromagnetic energy-momentum must have zero covariant four-divergence. However, vanishing of a covariant four-divergence in a curved spacetime is not a conservation law. The non-tensorial part corresponds to an exchange of energy-momentum between electromagnetism and gravity. It is coordinate-dependent and for that reason the very concept of “energy” becomes elusive and chimerical in GR. (I might even go so far as to suggest the heresy that in general relativity “energy” is not a valid physical concept!). That’s how I see the question in terms of fields. In terms of elementary particles, we would need to think of the interaction between photons and gravitons. In the spirit of quantum physics, we would expect a photon to interact with gravitons, just as it has interactions with other elementary particles. Why should it not? Indeed, we know it does - the bending of light in a gravitational field is a macroscopic consequence of those interactions. For a single photon the effect would be totally undetectable because of the extreme weakness of the gravitational interaction at the level of particle interactions. But as a matter of principle, we cannot just say the interactions don’t exist.

That’s the complicated answer. The simple answer is: curvature affects photons, therefore photons affect curvature (Newton’s “action and reaction"...)

Eric,

The existence of gravitons has not been established - only proposed in theory. See http://en.wikipedia.org/wiki/Graviton.  As I understand, we know only that discrete particles are affected by gravitational fields - it has not been established that discrete particles produce gravitational fields…

James ~

I entirely agree – the existence of “gravitons" is conjectural. Inevitably so, since the unified theory of gravitation and quantum theory is unknown. The original question mixes these two presently very different, apparently irreconcilable, kinds of theory, so it is inevitable that an attempt at an answer must also mix them. It can, in the present state of knowledge, only be tentatively answered with speculation and conjecture based on what we already know. My intuition suggests that the non-existence of gravitons is unlikely, for the following reason: the linear equations for spin-½ (Dirac), spin-1 (Maxwell and Proca) and spin-2 (f-mesons) are the foundations of quantum field theory. The linearised Einstein equations are identical to the equations of a massless spin-2 field, which would, when subjected to “second quantization”, give rise to massless spin-2 quanta. Moreover, when the linear spin-2 theory is self-coupled by introducing its own energy-momentum as a source term, the resulting non-linear equations become (miraculously!) identical to Einstein’s gravitational equations. It’s therefore hard for me to believe that, in a quantum theory that incorporates Einsteinian curved spacetime, there would be no gravitons. Admittedly, we simply do not know.

PS: you say "it has not been established that discrete particles produce gravitational fields…". I disagree. Discrete particles carry energy and momentum. Energy-momentum is the source of gravitational fields.

@Aleksey "Stefano read in paper by  Okun  that photon energy is constant during its motion in the gravity field of the Earth. He concluded, that photons can not interact with the gravity."

I don't conclude at all that photons don't interact with gravity, I simply say that the energy balance is zero, let's say an energy Exchange is possible but its net balance is 0. The space-time changes  the momenta of photons but since speed of light changes as well,  the balance of their interaction , energy wise, is zero.

MISNER THORNE WHEELER on the argument treating General Relativity Theory for example at page 659 paragraph "Gravitational Redshift" reports:

___________________________________________________________

"The conservation law |goo|1/2 *ELocal = constant, which is valid in this form for any time-independent metric with goj=0 and for particles with both zero and non-zero rest mass, is sometimes called the "law of energy red-shift". It describes how the locally measured energy of any particle or photon, changes (is "red-shifted" or "blue-shifted") as it climbs out of or falls into a static gravitational field. For a particle of zero rest mass (photon or neutrino), the locally measured energy Elocal and wavelength lamdalocal (not to be confused with affine parameter!), are related by ElOCaI = h/ lamdalocal  where h is Planck's constant. Consequently, the law of energy red-shift can be rewritten as  lamdalocal * |goo|-1/2 = constant.

__________________________________________________________________

The key sentence is the "locally measured energy".

Here we are taliking about the relative distorted perception of energy according to GRT in presence of different curvatures. No matter what entity, photons or leptons or quarks this variation law of "energy perception"  is independent of the intrinsic nature of what is inside. This is the main thing in which special relativity fails.

This, you might think, is against what I'm supporting,  instead it full supports it,

Photons follow only that law, no other shift is present and is relevant only to the way different curvature perceive the energy incoming.

Leptons and quarks instead posessing  in addition, in the non relativistic case, a actual gravitational potential energy will have a different Redshift in their De Broglie frequencies and anyway a different Redshift in the relativistic case.

The book talks also about other interpretations of the Gravitational Redshift but it puts them in a Chapter "incompatibility of gravity and special relativity" in which it reports the reasoning of Einstein of 1911.

I think that everybody here well understands  what happens in a gravitational potential for oscillator atoms. The changes of the energy levels of the oscillator atoms measuring the time,  is an absolute phenomenon (it actually related to the change of the speed of light). thus the photon is detected as changed in its frequency.

Aleksey you continue not to understand the real gist of the matter. YOu are talking about coordinate systems,

"In specific coordinate system - yes. But this is not absolute effect - it depends on the way you synhronize the time. In the case of constant metric there is a "prefered" way to synhronyze time "

Aleksey we are not talking about specific coordinate system, it is general relativity, only curvatures are defined point by point including the curvature at infinity which is supposed to be null or minimal.

"in other case you will note, that if energy of the photon is constant, but momentum is changing, enrgy will be changing in some other reference frame"

Speed of light changes Aleksei...speed of light..

@Aleksei

you wrote "in other case you will note, that if energy of the photon is constant, but momentum is changing, enrgy will be changing in some other reference frame"

Speed of light changes Aleksei...speed of light..according to local curvature

Aleksei,

Thanks but I’m afraid you’re misunderstanding me when you replied "No, my reference was correct" […] "But, if we all will look in derivation of the fact of conservation of the energy of a photon, we will see, that it can be applied to any particle. If ypu look at two paragraphs befor equation 88.9 in LL, you will see that it is not just my idea."

You originally referenced “Landau-Lifshitz "field theory" chapter "88.constant gravity field".”

My objection explained that “…you incorrectly reference section 88 in chapter 10 ("Particle in a Gravitational Field") of "THE CLASSICAL THEORY OF FIELDS".“ To explain further, "Chapter 10 Particle in a Gravitational Field" begins with Section 81 on page 225.

Throughout chapter 10, the gravitational field being discussed is that produced by a single massive object – not considering any energies that might be contributed by any discrete particle or even the collective energies of any group of particles (such as photons or any stellar wind. The only gravitational effects discussed are those of the field produced by a single massive object, including its electrical and magnetic fields...

Aleksei,

"By the way, spped of light changes according to metrics, not curvature"

I think you are talking about another theory. You have to seriously study the Einstein stress energy momentum tensor.

"But, please tell it Stefano, who used results of Okun's consideration of photon in the constant gravity field of the Earth (and for that case section 10 is appliable), made conclusion that photons can not interact with gravity (or now he changes his mind... but still he thinks that photons can never produce gravity), "

Wheeler subscribed that paper.

And I tell you another time the interaction is not necesarily with a net energy Exchange.  Tell Okun he his wrong, you certainly can.

Aleksey first I answer to this:

"Do you understand, that energy levels of atoms are coordinate-dependent? Do you know, that energy is transforming then we change coordinates? Do you know that metrics tensor (as well as curvature tensor...) transforms under coordinate transformations? Can you just may simple transofrmation

t'=g001/2t (or absolute value of g00 if you use -+++ signature)

x'=x

y'=y

z'=z

"

So you are affirming that in the same point in space

(X,Y,Z) = (X',Y',Z')  no doubt about it, otherwise go back to the secondary school.

There might be  different clock-rates....

t'=g001/2t..

Congratulations...

I thought I'd made it clear earlier that I doubt that discrete particles can produce gravitational effects - since there is no observational evidence directly supporting that claim. While it makes simple mathematical sense that - since massive objects exhibit large scale gravitational effects - it must be the product of their quantum components, that conclusion is based on the presumption that gravitation must be produced by a mechanism similar to electroweak interactions among elementary particles.

I also attempted to provide an example alternative mechanism by which gravitation is produced not by any interaction among discrete particles, but through the process of extracting mass-energy from spacetime - thereby creating a localized, geometric boundary condition between regions of mass-energy-depleted spacetime and condensed mass-energy material objects. In fact, it is the effects of that interaction (not the mechanism that produced it) that is described by the geometric mathematics of general relativity.

That the gravitational effects produced by discretely bound massive objects are proportional to some approximation of their components' mass-energy does not provide evidence that those effects are produced by quantum interactions among elementary particles - only that those effects are proportional to the collective mass-energy of the resulting condensed matter.

Sorry I can't produce an argument that is more compelling to physicists, but if one does not limit the potential explanations for gravitation to those that apply to 'the other fundamental force interactions of matter' (thereby conveniently fitting gravitation into the existing framework of quantum theory), perhaps their fundamental distinctions can be better explained!

James,

so you don't think leptons or quarks are sources of gravity if they are taken singularly??

Or what do you mean for single particles?

@ Aleksey

tell me one thing, the possiblity that a clock runs slower than another is dependent or independent on coordinates?

Stefano,

"so you don't think leptons or quarks are sources of gravity if they are taken singularly??"

In my example alternative mechanism, gravitation is not produced by particles of matter at all - singularly or collectively - it is a product of the exchange in local mass-energy density caused by the accretion of matter.

In a cloud of gas or dust, for example, mass-energy tends to distribute homogeneously. However, attractive EM charge interactions cause the clumping - weak binding - of particles, initiating the accretion process. While this clumping localizes or condenses what was once the disperse distribution of mass-energy, it necessarily also produces an equal and opposite reaction - the local depletion of mass-energy. Eventually, as the process proceeds, sufficient mass has been condensed - and vacuum depleted - to cause the emerging gravitational effects to dominate the continuing accretion process initiated by EM charge interactions.

In this way, I suggest that the redistribution of dimensional spacetime topology described by GR should be attributed primarily to the local depletion of mass-energy within the surrounding vacuum.

According to your point of view let me understand, it is based on the formation of stars..

 the Einstein Energy- momentum tensor exists, the space-time curvature exists, but this is not determined by the contribution of  single particles... I need to have more details... 

Thanks Charles...

http://www.rqgravity.net/Gravitation#hn_The_Stress-Energy_Tensor

“We know from observation that matter is the source of the gravitational field.”

What we ‘know’ (actually, conclude) from observation is that condensed objects of mass appear to be causally associated with gravitational effects.  We also know that the effects of gravitation produce condensed objects of mass...

I'm describing a conceptual alternative mechanism to the presumed quantum particle interaction for the production of gravitational effects. The mass-energy density gradient represented by condensed objects of mass is equal to the mass-energy extracted from dimensional spacetime by the process of accretion – except that gravitation is described by dimensional length contraction and time dilation (‘curvature of spacetime’), which functionallly correspond more closely to the necessary reduction in the prevailing mass-energy density of the ‘vacuum’ prior to accretion. This is true whether the object is a star or a sufficiently massive dust cloud.

In this mechanism it is the local contraction of dimensional spacetime that adjusts to the depleted mass-energy density of the ‘vacuum’ to maintain consistency – not any dynamic interaction between particles. Einstein did not describe any material interaction that physically produces the effects he described in GR. I contend that the contraction of spacetime is better represented by this mechanism than any particle mediated particle-particle interaction.

Sorry that I cannot submit any formal theory to better explain – I’m merely a retired information systems analyst.  I realize that the physics community is very strongly motivated to fit gravitation into the framework of quantum theory - as 'one of the four fundamental forces' of matter, but the possibilty that it is not causally related must be considered - especially since its characteristics are quite distinct from the 'other' three.  I do not hope to overcome that natural bias here.

Charles, can you not consider that the extraction of mass-energy density from the vacuum, the equal and opposite reaction to mass-energy condensation, functionally corresponds to the dimensional contraction/dilation of spacetime?

Just as gravitation is not involved in the initial accretion of massive objects - gravitation can be an emergent interaction between spacetime and material energy rather than a fundamental particle interaction...

Dear Stefano, I do not want to intervene, but I think you should probably find interesting to read some other views:

• about time: https://www.researchgate.net/publication/263104630
• realtivities: https://www.researchgate.net/publication/264357957
• cosmology: https://www.researchgate.net/publication/264537258
• the concept of unidirectional relativity:https://www.researchgate.net/publication/265471655 and you have to read the book of Johan Prins: https://www.researchgate.net/publication/265163606 and other works of him.

As for 'billiard physics', take a look at the discussions here:

https://www.researchgate.net/post/What_is_your_opinion_regarding_Billiard-Physics

You have touched a theme with great importance and great disagreements among scientists!

Article A simple definition of Time

Article Why relativity theories cannot serve as a cosmological paradigm

Article A new cosmological paradigm: universal locality

Data A five page review of the August 30, 2014 version of the Boo...

Book Updated: Einstein=Genius: But a genius sometimes blunders

Thanks a lot Demetris,

@ Charles:

"The metric of space time emerges from exchanges of photons between charged particles, just as does e.m. itself."

Do you mean that the space-time fabric itself and so its curvature should come out of (virtual) photons?? Explain...

Aleksei go to study well GRT. You didn't understand the main thing of GR

"In general case... how would you define "lock runs slower than another "? Just think about it. And, since this notion has no general snse in general case, it is not fundamental. "

GO TO STUDY GR AND EXPERIMENTS I don't even want to talk about it

@ Charles,

Sure if I explain the EM field which determines the underlying matter/energy in term of virtual photons, which is the QED point of view.

Aleksei,

you still prove didn't understand the gist of GRT.

I'm sorry.

I may suggest you the Hafele and Keating experiment, and the way you can really get rid of  in such case of reference systems.

I speak with people who are able to understand GRT.

That is enough.

Stafano ~

Why are you so impatient with Aleksei? He appears to be struggling with the possibility of comparing rates of distant clocks in a curved spacetime, using light signals, and concluding that it is a formidable problem. Which indeed it is. I can't see much wrong in what he's trying to express.

@ Aleksei. Continue to ignore...

The difference of proper times between two point in space-time, in a static situation is absolute, it is the base of UCR, UNIVERSALITY OF CLOCK RATES.

I know that in order to test the relation the HK experiment had to use the SW framework, because it had to get rid of the inertial time dilation.

But you understand that the SW metric in the "approximation in which it is calculated" represents an absolute configuration or not????

Do you understand that if I take two atomic clocks, considering only the configuration of the masses around me without any reference systems, and I move that clock, that clock if it will present a time difference it will be independent on the reference frame since I didn't use it?????? Or should I be more clear???

@ Eric

"Why are you so impatient with Aleksei? He appears to be struggling with the possibility of comparing rates of distant clocks in a curved spacetime, "

He wrote:

"As you should know, in even special relativity there is no way to say that moving clocks operates faster or slower. In the case of constant gravity we managed this problem by fixing clocks relative to the source of gravity. In general case there is no such unmovable fing we can fix our clocks relative to"

This is obvious. Only by fixing the configuration of the masses we can calculate the relative delay of clocks being able to define energies at stake which are the only things which curve the space-time and affect the clockrates.

In SR such problem is a "ill posed problem" 

It is also obvious that the Schw. solution is an approximation, which experimentally works till a certain accuracy, because

1) doesn't consider the mass of the observers

2) approximates everything to a homogeneous spherical mass

    universe simplifiled as acting like that on any mass nothing is said about what happens inside the spherical massive object (for this other metrics  Oppenheimer Volkoff Tolman)

What  doesn't seem obvious, as far as I can see, is that once the configuration of masses is defined,  it is also defined the difference of clockrates between moving clocks in space. This doesn't depend on any reference systems whatsoever.

Another thing is the way we calculate the difference of the clock rates, it is as an approximation whose accuracy depends on the model used. With the SCW solution a certain degree of accuracty in the field of Earth can be found. Other models have to be found for other configurations, but this is obvious.

"Remeber falling elevator? If you do this experiment inside your elevator you will see that proper time difference is in exact agreement with special relativity prediction: gravity can not be observed locally in free falling"

Dear Aleksei again.

Do you really think that all the gravitational effects can be cancelled out by free falling???

@Aleksei

You think I ignore, presume, insinuate.

"you ignore. I mean some particular thing obvious for anyone who understands first chapters of any book on general relativity. Remember, we are discussing difference in clocks rate at to nearby spacepoints with "gravity potentials" (let us consider static gravity for a moment) different by the small value. "

These clocks actually have different clock rates, don't they?

So it is enough to have two clocks in the elevator one on the top of another even at very small distances...they will posess a different clock rates.

@Aleksei

"You should know how matter produces the gravity - it seems that for the moment you do not know that. "

what do you mean??

At which level specify please.

Matter energy stress tensor?

if it is regarding "virtual photons", it is not enough. Since the most of the energy is cconcentrated in the nucleus and there, something else is present, rather than Virtual Photons which accont only for quantum electrodynamics.

Or you are talking about the structure of Space-time fabric, then I don't really know who knows it. 

Maybe you know it, since you seem to know everything.

Or you are talking about Zero Point energy???

Specify better when you write.

Aleksey so every falling clock beat the "real same time"???

We are talking about actual, real not apparent.

There is no uniform gravity dear...it is a nonsense approximation

Dear Charles,

here comes the big paradox...... if all  the free falling clocks beat the same proper time, what is their clockrate???

So you are affirming that in the universe all the clock-rates of the free falling clocks are the same...we are talking about proper time which is not apparent, but is the actual.

Is it this??

So my question was fare. All the effects of local curvature are virtually cancelled by the free fall, according to equivalence...