If you consider light in motion as a wave (as it is in EM models and I think also in current mainstream physics) then you can’t expect it to work like matter. The speed of light is the speed at which EM waves propagate. Causality is the same because many interactions are mediated by exchange of photons via EM waves.
The speed of light in aluminium is ~0.95c, the EM waves in an aluminium antenna aren’t going to interact outside the aluminium faster than 0.95c. I would bet the effective speed of causality would never be greater than the speed of light in whatever medium the light is in
As I understand, neutrons and gravitational waves are also bound by the speed of causality, because they have no mass. And I believe, unlike light, they are unaffected by electromagnetic forces that a material exerts, so they would presumably (always?) travel faster than light in that medium.
I will also say, that from what little I understand of this video: https://www.pbs.org/video/pbs-space-time-speed-light-not-about-light/
…it sounds like trying to determine the speed of causality by measuring it, is kind of backwards. You’re at best experimentally confirming what has to be a given under our laws of physics.
If you consider light in motion as a wave (as it is in EM models and I think also in current mainstream physics) then you can’t expect it to work like matter. The speed of light is the speed at which EM waves propagate. Causality is the same because many interactions are mediated by exchange of photons via EM waves.
The speed of light in aluminium is ~0.95c, the EM waves in an aluminium antenna aren’t going to interact outside the aluminium faster than 0.95c. I would bet the effective speed of causality would never be greater than the speed of light in whatever medium the light is in
I’m no expert. I probably know too little about the propagation speed of a wave to understand what you mean there.
But here is a scenario where something is faster than light in the given medium: https://en.wikipedia.org/wiki/Cherenkov_radiation
As I understand, neutrons and gravitational waves are also bound by the speed of causality, because they have no mass. And I believe, unlike light, they are unaffected by electromagnetic forces that a material exerts, so they would presumably (always?) travel faster than light in that medium.
I will also say, that from what little I understand of this video: https://www.pbs.org/video/pbs-space-time-speed-light-not-about-light/
…it sounds like trying to determine the speed of causality by measuring it, is kind of backwards. You’re at best experimentally confirming what has to be a given under our laws of physics.