If light was 2 parts per trillion slower than gravitational waves, would we know this from Gauss' law?
136433
Why did the gamma ray burst from GW170817 lag two seconds behind the gravitational wave?
47941
Would you hear a gravitational wave, if its amplitude and frequency were suitable?
2154
Why doesn't gravity speed up light?
77372
"Speed" of Gravity and Speed of Light
106119
Why is there no permittivity-type constant for gravitation?
155345
Can we use curved spacetime to measure the one-way speed of light?
19850
Why is the speed of light defined as 299792458 m/s?
149674
Kinetic energy of a photon and Schwarzschild radius
123571
A change in the gravitational law
90400
Would it be possible to transmit information through gravitational waves?
4344
speed of gravitational waves
81410
How fast a (relatively) small black hole will consume the Earth?
147587
Do gravitational waves slow down as they pass through matter?
47568
Is it experimentally proven that photons travel at speed $c$ in vacuum?
76779
Are there bound states from light-light or gravity-gravity scattering in general relativity?
54193
Can light exist in $2+1$ or $1+1$ spacetime dimensions?
7618
What is the speed of light relative to?