Light travels at c in a vacuum. That includes the vacuum between
atoms in matter.
Light traveling "through" an atom is absorbed, and then normally re-
emitted at exactly the same polarization, speed (c) and frequency,
with a slight time delay due to interactions with the electromagnetic
fields within the atom.
For details see any comprehensive text on Special Relativity. Also
research "polarizability" and the dielectric constant, as colligative
properties of matter.
A good text on the theory of the complex refractive index may also be
helpful.
Tom Davidson
Richmond, VA
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"But the ray moves relatively to the initial point of k, when measured in
the stationary system, with the velocity c-v"
That's in a comprehensive text on Special Relativity, namely
http://www.fourmilab.ch/etexts/einstein/specrel/www/
You are bullshitting, Little Tommy Davidson.
Someone wants their cake and eat it too, the crumbs are on your face.
