Dear Stefano,

I didn't follow in detail the references that you suggest, sorry. But the velocity of the light only depends of the electric and magnetic properties of the medium and this cannot change by any kind of reflections or even gravitational potentials.

Dear Daniel,

these quantities are consequence of measurements with instruments.

The instruments are affected as well by the same speed of light, so you cannot really notice if the constants changed or not.

What you see is a refraction of EM waves due to gravitational field which tells you that globally those coefficients are not the same..

Dear Stefano,

I'm not sure to understand you, but I said is very simple: the velocity of light only depends of the permittivity and permeability of the medium, nothing more. There are not a usually definition of velocity as in mechanics where space and time are well defined and explicitally assumed. Here (in the electromagnetic field or in the photons) such definition is not possible because time is not defined at all. Thus measurements of velocities close to a metallic boundary are very difficult to stablish or even to find due to the relative small distances to consider.

Dear Daniel,

you teach me that the speed of light is in relation with the vacuum EM constants.

Do you really support the fact that the EM constants are always the same or we simply measure them as being the same "locally". Consider infact that since any variation of them affect our instrumentation as well, it is possible that we cannot see locally such variation...

Dear Stefano,

I'm not sure to follow you well when you write:

SQ> Do you really support the fact that the EM constants are always the same or we simply measure them as being the same "locally". Consider infact that since any variation of them affect our instrumentation as well, it is possible that we cannot see locally such variation...

But if you ask me about how the electric and magnetic vacuum properties are measured, I must humbly say that I don't know and I only assume them as constants. For me there are nothing that can change their value, but even if they would be with a different value, that would not be too important for the Lorentz transformations. What is for me important is that they were working for a long time very well respect to Electrodynamics and the rest of interactions taking c as a constant. I cannot imagine what could be the effect to have c variable in vacuum.

Dear Daniel,

locally I can agree with you..

yes, but not without "issues" like the need to resort to the re-normalization in order to get good results and missing unification with gravitation.

it can be everything...imagine for example that very tiny changes, impossible to detect with instruments may results in all the dynamics we know, including gravitation.

It is quite interesting the view point of Abraham in this regards..

Hi Stefano,

The values of permittivity and permeability are scalars, they have a single value when measured which doesn't depend on direction. That means light is isotropic even if it has different values in a medium due to the refractive index. Reflecting light off a mirror therefore cannot change the speed, it has to have the same value when reflected as it does when approaching the mirror.

Sure the speed of light cannot change due to the reflecting mirror, it would be difficult to make the RDE work.

Dear Stefano and George,

Although the velocity of the light don't change under the reflection on a metallic surface, the way that is done is quite special. In act there is only one inversion of the coordinate perpendicular to the surface which reflects. The reason is due to have for the Poynting vector a product of a polar vector E by a non-polar one B (in fact a two antisymmetric tensor on three dimensions). This tell us that even the electric permitivity and the magnetic permeability in vacuum are not trivial scalars because they must carry the geometric information of the spacetime in the transformation B= mu H and the same in D= epsilon E where E and H are real vectors (fields) while B and D are not vectors at all, although by their product with a Levi-Civita tensor they can get it in vacuum.

Therefore George this issue is not so simple and it is related with discrete symmetries as P (parity) in the Lorentz group of transformations of Electrodynamics which we have examined many years ago and collected some results in the book of Geometry of Electromagnetic Systems written by Percy and me.

Hi all,

If you have a real interest in electromagnetic phenomena in relation with the signal velocity, I can refere you to the Daon theory, first part (The Electron) it gives you a general explanation to EM as well as, associated wave, fine structure constant, mass increase etc. of the electron. A more general approach to SR will be presented later.

Dear Daniel,

I understand that the behavior of the EM constants is not trivial. I don't see though what could prevent them from changing as a function of the matter-energy content in their neighborhood.

Einstein himself when calculating for the first time the light bending caused by a celestial body, found it as a variation of the speed of light due to gravitation, fixing some coordinates for example the center of the celestial body (any trivial "attraction" has to be excluded, no ballistic behaviour).

Eddington et al. made a second step and modelled it as a refraction index due to gravitation, expressible with a variable property of an "Hypermedium" due to the mass of the SUN.

The "curvature" in itself is a "mathematical artifact" of another "mathematical artifact", the space-time which so far in many cases has worked fine in explaining phenomena. SR is firmly based on c always constant, in GR c changes this paradigm although c preserves its constancy locally.

Dear Stefano,

The velocity of light is a fundamental result of Classical Electromagnetism and very well known in Optics and even in Astronomy. Einstein only took this result as a postulate of his Special Relativity Theory (SRT) because its existance breaks obviously the Galilean addition of relativities. Thus as previously Lorentz or Poincaré saw this fact would be against the usual Newtonian Mechanics although Maxwell Electrodynamics was kept invariant and properly transformed under a change of coordinates. In fact SRT was the proper background for Electrodynamics.

But what happens with Gravitation? The General Relativity Theory (GRT) is an attempt to joint SRT and Newton Gravitation. But what happens with the velocity of light in this new physical context? Notice that a natural idea here is to joint Electrodynamics with Gravitation which has failed. Thus your question is necessary to examine with care because light is Electromagnetic field.The curious thing is that Gravitation in GRT is just a geometric background (Riemann geometry) associated to the spacetime which is related with the Minkowskian (SRT) thanks to the Equivalence Principle. Therefore Gravitation is actually not a physical interaction as Newton's Gravitation was: there are not gravitational force but a geodesic motion within the curved spacetime. This is true also for light and therefore its physical features are the same as in SRT when we think in its velocity. The velocity of the light is only dependent of the permittivity and the permeability of the vacuum. Nothing more, notice that if this were not true we could solve the unification or no independence of gravitation and electrodynamics. This is not true! It is true that gravitation introduce a curvature which makes the velocity of light go for another trajectory that it would go in SRT, but the local velocity of the light is always a constant independent of the gravitation field.

I'm sorry for writing so long post. Sorry.

Dear Daniel,

I can understand why..

it manifests itself as containing E and B when it is again coupled with matter.

Before any discussion of light phenomena, you have to separate between EM-waves and photons. They are two different phenomena! The modification of wave-length due to the movement of the source is a typical wave-phenomenon, but this has nothing to do with the photons.

Dear Stellan,

Could you elaborate a little bit your post? As you know the electromagnetic field is assumed to be formed by photons and thefore the electromagnetic waves. How do you distinguish the photons from the electromagnetic waves? Thanks

Dear Daniel

You have belove the experimental prof that the EM field is not produced by photon exchange:

R. de Sangro, G. Finocchio, P. Patteri, M. Piccolo, G. Pizzella "Measuring Propagation speed of Coulomb Fields". arxiv:1211.2913 [gr-qc] 10/11-2014

A description of the phenomenon of EM-waves is given in The Daon Theory: (the first part) The Electron . It is an oscillation within the media.

The photon will be treated in part three of the Daon Theory (Particles).

The photon is a particle which doesn't follow the Einstein's mass formula (as also the neutrino)! It is quickly accelerating at the moment it obtains a velocity (at the moment of creation) and it stops at the limit of the signal velocity within the media. The acceleration depends on the mass (energy) of the photon, the heavier the slower. The photon obtains an energy (mass) at its creation which is constant during the phase of acceleration.

Dear Stellan,

Are you speaking of a "new Physics" for solving what difficulty? Electrodynamics is very well established classically and quantically? What do you solve new with your model?

It is always assumed that the photons are particles that cannot be accelerated and therefore I don't understand that you write sentences as:

It is quickly accelerating at the moment it obtains a velocity

The mass of the photon is zero and cannot support an external force as you say and the reference of the arxiv is not mentioning anything related with photons directly. In fact they assume them in the synchroton radiation measurements.

Dear Daniel,

The arxiv reference shows that the electrical field around an electron is not a photon exchange! That means that the QM description of electrodynamics is wrong.

The knowledge of the photon is very scares, do you really believe that a particle without mass can have energy?

The novel approach of the Daon theory give logical and simple answers to any phenomenon of physics, and that using only three parameters (in fact it's using only one, which is the size of the daon) .

The characteristics of the daon makes it accelerate through the interaction with the media. I can not give you a more precise picture at the moment. If you read through the first part of the daon theory, I could be more precise.

Dear Stellan,

Let me to attach the link of such paper (published 2014).

Article Measuring Propagation Speed of Coulomb Fields

I don't see what do you mean by

he electrical field around an electron is not a photon exchange!

Notice that the photon is a particle very well known in many different fields of Physics and still don't understand by your explanation the need of your daons and what could they solve. Please be more explicit!

Dear Daniel,

Reading the cited paper, for me the conclusion, which they make, i.e; the coulomb field is located directly at the center of the electron, seems obvious. This means that there is no photon exchange, since the photons must come with the delayed potential. This type of exchange is excluded by the experimental setup.

Now, about the usefulness of the Daon theory:

I can agree, a bit, what is concerning the EM-fields, since the contribution of a better understanding do not change much in the application of EM-fields.

The same can be said about part three and four of the daon theory; they are treating particles and gravitation cosmology. That is, they bring a complete understanding within each field, but, the application, of such an understanding, is not evident.

But, I must disagree white the second part ( which should be finished before November); this part explains the electrons behaviour within the atom. It includes a program which is able to calculate any parameter of any particle within the atom; including position, velocity, energy... at a given time. This means that it is an understanding on a much deeper level then the QM.

This a program can be developed to include molecules. A fast computer can then study things like medicine, condense matter, supra conductivity...

That is, it will be a valuable instrument to many fields of applied physics.

Dear Stellan,

The paper only works with classical electrodynamics and never with photons. Your sentence:

SG wrote This means that there is no photon exchange, since the photons must come with the delayed potential

is not right at all. The photons never take delayed potentials ( even if they are obtained from a Lienard Wiechert potential). Do you distinguish photons of different potentials, how?

Respect to the daons, I'm sorry but I think that you are deeply wrong when you write:

SG wrote: explains the electrons behaviour within the atom. It includes a program which is able to calculate any parameter of any particle within the atom; including position, velocity, energy... at a given time

Obviously this is against Quantum Mechanics, no complements it, and you need to explain things as how you avoid the Heisenberg principle and so.

Dear Daniel,

Let us avoid further discussion on the photons, I think we will continue to disagree, so there is no point.

Concerning the Daon theory; you will have to patience a bit. Of course is not building on the QM, It is a completely different approach. The basics of the QM makes it impossible to examine anything smaller then the associated wavelength.

So it is necessary to take a completely different approach to be able to advance.

That is exactly what the daon theory is doing.

Dear Stellan,

QM works quite well and it is very close to the experiment, I think that a new theory needs to justify what is going to improve clearly.

Dear Mohamed,

The findings of the experiment is what it is. If you (or themselves) want to believe it our not.

Hi Daniel,

DB: Therefore George this issue is not so simple ...

Yes, I'm aware of that but I was trying to keep the response at a level that is in keeping with Stefano's level of knowledge. If we think of light passing through a small box then, after it exists it hits a reflection surface of some kind, then passes back through the box, the permeability and permittivity within the box say that the speed in both directions in simple classical theory is 1/√(μ0ε0) hence it must be isotropic. It doesn't matter what caused the reflection. I suspect that is what Einstein meant when he said that it was Maxwell's Equations that led him to SR and formed the basis of his second postulate. The more complex aspects you mention historically came later.

Article CO-ACCELERATED CLOCKS maintain their synchronization?

Here it is the key contribution of Abraham about a theory which could unify the interactions 100 years ago.

A spatially-VSL gravity model with 1-PN limit of GRT Jan Broekaert ∗ October 8, 2018

https://arxiv.org/pdf/gr-qc/0405015.pdf

An interesting comparison between the Lorentz' conception and the Einstein's one about time and Light.

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