Reality Check
Penultimate Amazing
Slightly wrong, Mike Helland.Snell's law predicts a change in reflection angle based on speed.
Snell's law is based on a difference in speed and other principles. Light travels at c in a vacuum. Light in a medium travels at c/n where n is the refractive index. Media with 2 different refractive index give 2 different speeds. That difference says nothing about refraction. Fermat's derivation adds Fermat's principle, etc.
QED does not use your "decelerated photon in a vacuum". Read what you have cited. Read what you have been cited. QED gives reflection from a mirror based on Feynman paths where light travels at the speed of light c. QED is a relativistic theory! It includes the 2 postulates of special relativity. One is that the speed of light in a vacuum is constant for inertial observers.QED doesn't, for a decelerated photon in a vacuum, ...
But more importantly, we are not discussing QED and Snell's law
Feynman Paths
Optics: The Principle of Least Time.
The second of Richard Feynman - Science Videos.
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