Is there variation in the speed of light?
1206
GR. Einstein's 1911 Paper: On the Influence of Gravitation on the Propagation of Light
17152
Do all massless particles (e.g. photon, graviton, gluon) necessarily have the same speed $c$?
155345
Can we use curved spacetime to measure the one-way speed of light?
13563
What really causes light/photons to appear slower in media?
93598
Is it proven experimentally that the speed of causality (light) is the maximum speed?
86328
What is the relative speed of two near-light speed particles headed towards each other?
119639
Do photons bend spacetime or not?
8367
What do physicists mean when they say "speed of light"?
120679
Rømer's determination of the speed of light
120621
Speed of Dark experiment, does it *really* travel faster than light?
58728
Why does the speed of light in vacuum have no uncertainty?
10781
Accelerating particles to speeds infinitesimally close to the speed of light?
14036
What is so special about speed of light in vacuum?
62039
What does a sphere moving close to the speed of light look like?
56005
Speed of light travel
106874
Does mass affect speed of orbit at a certain distance?
4005
If refraction slows down light, isn't it possible to hold light still?