the speed of light is only guaranteed to have a value of 299,792,458 m/s when measured by an inertial observer in a vacuum.
This is the average speed of photons in vacuum, right? Because according to the quantum field theory, photons should have a probability of hitting virtual particles that popped into existence, which would slow it down a little.
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This is the average speed of photons in vacuum, right? Because according to the quantum field theory, photons should have a probability of hitting virtual particles that popped into existence, which would slow it down a little.
Ward-Takahashi identities prevent, in some sense, the virtual particles from screwing up the speed of light.