Dear Jaafar,

if due to the electric field for example a) the refractive index is changed and b) for example due to a gradient of that field the refractive index shows up a also gradient, then the light path will have a curvature according this gradient.

But for light propagating in vaccum it is only known to me that light propagation deviating from a straight line is only observed in the presence of a strong gravitational field such as that of the sun, black hole or neutron star.

Dear Jaafar,

if due to the electric field for example a) the refractive index is changed and b) for example due to a gradient of that field the refractive index shows up a also gradient, then the light path will have a curvature according this gradient.

But for light propagating in vaccum it is only known to me that light propagation deviating from a straight line is only observed in the presence of a strong gravitational field such as that of the sun, black hole or neutron star.

Thank you so much for your answer dear Gerhard,

What's I'm looking for is what you are describing in second paragraph.

As you say, the path of light is deviated by a strong gravitational field. It is well known that an electron is a point particle, but I imagine that an electron is made of a quantum energy which always in circular rotation in positive direction (positron in negative one) with a speed higher than C around a finite spheric volume having a radius around Planck length (1.62x 10-20 fm) filled by a strong gravitational field. I imagined as this, to understand why In standard model a photon acts as boson vector particle which is responsible of EM force and why two electrons can exchange virtual photon. Also in case of e+,e- annihilation process, two captive photons inside electron an positron are liberated in two opposed directions. My supposition make sense or not?

Dear Jaafar,

Magnetic fields certainly affect the path of light, at least with regards to its polarization.

It is precisely the observation By Faraday that light can be polarized by electromagnets that led Maxwell to conclude that light moving at c was due to light propagation was due to self-sustaining mutual induction of both electric and magnetic fields that light must be made of.

Regarding your hypothesis that electrons can move at speeds higher than c in vacuum. This is physically impossible.

The idea other than highly theoretical that electrons could move at velocities higher than c around finite spherical volumes having Planck Length radius filled with a strong gravitational fields is just speculation about a situation that can not occur in physical reality.

That the photon must be a boson is mandated by the simple fact that it can be transversally polarized, which is the accepted view since de Broglie related polarization of the photon to spin 1.

Exchange of "virtual photons" is something else entirely. Related to the Coulomb Interaction and corresponding enegy level as quantized by QFT and computable with QED.

You write "Also in case of e+,e- annihilation process, two captive photons inside electron an positron are liberated in two opposed directions. My supposition make sense or not?"

Not really. Positronium annihilation of an e+,e- pair involves the "conversion" of the energy making up both massive particles to electromagnetic photons state, not the emission of two photons that would be captive inside the particles. It is the very substance of which electrons and positrons are made that converts to electromagnetic energy.

The reverse also occurs. Blackett and Occhialini observed the conversion of 1.022 MeV or more electromagnetic photons to pairs of electron-positron in the early 1930's already as they grazed massive nuclei.

McDonald et al. produced electron-positron pairs in 1997 at the SLAC accelerator from two photon beams intersecting at a single point in space with no massive nuclei around, one of which beam being made of photons of energy exceeding 1.022 MeV.

The path light takes is not usually affected by the presence of a magnetic field. Light itself is composed of an oscillating electric and magnetic field, and one very important property of electric and magnetic fields is what we call "linearity."

That is, if you have two sources of electric and/or magnetic fields, you can predict what the combined field is just by adding the two source fields together. The two fields don’t change each other at all. So if you add the field of a light ray to any other field we can imagine, the light ray will continue as before and the extra field will just stay the same, adding to it in places where the extra field is strong, but having no effect beyond the reach of the extra field. So there is no way that a magnetic field can bend light.

Dear André,

Thank you so much for your clear and helpful explanation. Sorry if my idea did not well explained, but, I didn't say that the electron travel with a speed greater than C in vacuum. I wanted to say somethings about electron structure, I imagined an electron composed by two finite spheres :

1- a quantum energy (photon) in circular rotation ( angular speed > C x radious) around:

2- a finite spheric volume having a radius around Planck length (1.62x 10-20 fm) filled by a strong gravitational field.

I have imagined this scenario by taken into account that photon as particle has a mass of 10-54 kg according to

https://physics.stackexchange.com/questions/254677/if-photons-end-up-having-a-tiny-mass-say-10-54-rm-kg-what-would-be-the-u

In other word, I imagined that same as electron turns around the nucleus, electrons themselves is composed by a photon turns around a finite sphere having a strong gravitational field.

Dear Jaafar,

I see.

Well, I think then that your theory is as good as any around, since no completely compliant electromagnetic inner structure has been conclusively established for the photon.

This is precisely the current edge of the unknown as far as understanding the inner structure of localized electromagnetic particles is concerned, such as electromagnetic photons and electrons.

Since light is electromagnetic in nature, seems to me that electric and magnetic fields need to be involved in the description of photons if considered localized. But again, all avenues need to be explored.

Best Regards

Since photons of EM does not contain electric charge so it will not coupled to its own EM field so it should not be affected by electric or magnetic field at all. While in the case of gravitation, the graviton itself couples to gravitaional field of its own (hence nonlinearity arises unlike EM).

Dear Andre,

I agree with you and I think that such electromagnetic inner structure for photon can be probably discovered in experiments that generate gamma-gamma interaction known as light-by-light scattering which is recently observed by atlas collaboration at cern.

Photons don't interact with eachother in QED. But still at high frequency photon energy may fluctuate enough by uncertainty prinpicle to produce fermion-antifermion pair which then interact with another photon and hence give rise to photon-photon scattering.

Dear Jaafar,

If you also think that the inner structure of localized photons is electromagnetic, then maybe you will be interested in this paper, where such an inner structure is proposed, grounded on Louis de Broglie hypothesis:

https://www.omicsonline.org/open-access/on-de-broglies-doubleparticle-photon-hypothesis-2090-0902-1000153.pdf

Thank you for your useful link dear Andre, and I thank also others who answered this question.

Best regards,

Electromagnetic waves are like sine waves. On the average, they do not affect the back ground electric and magnetic field. They can not create DC component for electric field.

Path of light is affected by the dielectric properties of the medium. The dielectric properties are based on the polarization of charged particle in the medium and also some times by the presence of free electrons and ions. The effects become complicated when there is a back ground magnetic field. You may be surprised to know that there will be two types of velocities are introduced because of the dielectrics. The phase velocity can be zero. At this point wave is fully absorbed. The phase velocity can be infinite. At this the wave is reflected back. The group velocity with which the energy is transported remains equal to or less than velocity of light. You can catch these waves if you have a medium that exists on Sun. The electric field component component which is equal to magnetic field component in free space, reduces and can become almost 0. These are called Magneto Hydro Dynamic waves. In general External electric and magnetic fields do affect the path of electro-magnetic waves, provided that the medium is partially or fully conducting. You may say that the refractive index is directly related with the change of path. This is one example.

You will get many answers if you get any elementary plasma physics book. These books discuss the propagation of electro-magnetic waves in ionised media.

Photon has kinetic mass mp= h nu/c² ( nu is frequency, c is velocity of light and h is Planck constant. This mass is attracted by any massive bode. The force far away from the center of the massive object can be guessed to be equal to

F= mp G M /R².. This force bends the light. If it propagating perpendicular to the direction of force, then the bending will be approximated by

tan theta= mp *velocity ( F*time). Here theta is the angle of bending. This is approximated.

The gradient in refractive indices can bend the ray, slow or speed up the ray. This picture is based on the intensity of the wave. If the intensity is very large then the nonlinear effects will lead to wave-wave scattering. This is responsible for nonlinear optics.