If a massless observer is going at the speed of light, what speed will it measure of a light beam going parallel to it?
13251
Does a photon in vacuum have a rest frame?
47568
Is it experimentally proven that photons travel at speed $c$ in vacuum?
28488
I am confused about the idea that the speed of light is independent of the speed of the source of light
119953
What is the meaning of speed of light $c$ in $E=mc^2$?
96657
The speed of light as it approaches a massive body
123854
Would time speed up near a large body of negative mass relative to observers in micro gravity?
55971
Why does the (relativistic) mass of an object increase when its speed approaches that of light?
61714
Can One-Way Speed of Light be Instantaneous?
37941
Can light travel slower than the maximum?
58728
Why does the speed of light in vacuum have no uncertainty?
50289
The vacuum light speed: Is it really constant, i.e., independent of location in space-time?
57773
About the speed of light and gravity
15685
Does slowing light violate relativity?
115572
Theoretical proof of the constant of speed of light $c$ in vacuum in all frames of references
75580
Derivation of the speed of light using the integral forms of Maxwell's Equations
128320
In superluminal phase velocities, what is it that is traveling faster than light?
97032
Does light accelerate or slow down during reflection?