Anonymous said...
The velocity of light is a constant. The perception of it being slower when passing through a non-vacuum is due to the time lost to photons being absorbed and re-emitted by the matter it is passing through. During those times when the photon (or any massless particle) exists as an independent particle, it travels at exactly C. Refer to the field of quantum electrodynamics for details.
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I am going to discuss each point.
1) The velocity of light is a constant.
The velocity of light changes in the presence of a magnetic field. This is the Zeeman Effect.
That is a change in velocity of light in the presence of a magnetic field.
There are equations that describe the Zeeman Effect.
But, that is the halting of the rotation of the photon's data over a distance created by a magnetic field.
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A photon always passes through a medium. There is no possible way to create a magnetic vacuum in our galactic cluster. Everything between the Earth and the Magnetosphere is in a magnetic field. Everything between the Sun and the Heliosphere is in a magnetic field. This even extends to galaxies. As we see in this picture.
Caption: This is a false color image of the central region of a galaxy group in X-rays. The jet of matter blown out of the central black hole can be clearly identified by its radio luminosity (overlaid, purple-blue).
Credit: Image: S. Giodini/A. Finoguenov/MPE
Credit: Image: S. Giodini/A. Finoguenov/MPE
Photons from those visible background galaxies are impacted by the magnetic field of galaxies closer to us. These massive magnetic field show that gravitational lensing has nothing to do with gravity.
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