1) Do you imagine that mechanism of motion of matter and of light are different? Why? Lets assert that the motion is the same mechanism since you can convert matter to light and light to matter, they move the same way.
2) You can detect the position of matter and see its in motion. e.g. where is the electron? measure it twice and its moved between the two times.
3) So everything is in motion, including matter.
4) But stationary matter does not move overall, relative to a nearby stationary reference object, so the motion of matter results in no net movement over time. It just traces out the scale and shape of the object. In this case the electron.
5) So the scale/size of the electron that it traces out, depends on the mechanism of motion that also moves light.
6) And if the scale of matter was 2x larger, then the motion of light would move 2x as much. Because the mechanism of both motions is the same, see 1.
7) And if the scale was 2x larger in one axis, then the motion of light in that axis would be 2x larger.
8) So the apparent evenness of space in all directions is an illusion. It can be different and we would not measure any difference.
In other words, the speed of light is just a fixed arbitrary ratio. You measure it relative to matter, and matter can change size and the speed of light would change with it.
We chose a value for second (atomic clocks measure oscillations in a chosen nucleus) and so we set the value of that ratio when we chose that unit of time.
@"Pedants may then annoy you by noting that with the (strong) light-matter coupling required for this, your signals are no longer just electromagnetic, and as such are not longer really just "light"."
It is light and its always electromagnetic. Even when passing through a medium, even when that medium is the space between planets. Your magic lighty-matter thing needed to differentiate the light-through-matter case does not exist. Anymore than a light-planet motion exists that bends light with a different mechanism.
A few other things:
Your detector is made of matter and is also in motion. You never see the real shape of an electron you only measure the difference between the electron and the detector. The shape and size you imagine these particles are, is the difference between your detector and the particle.
This is also true of light (I'm not just talking about red shift, a zero hertz EM wave would have the same motion as the matter you detect it with, its true of all the components of its motion, its polarization, and many more complex oscillations, they are all the difference between the motion in the detector and the motion in the light).
Two atomic clocks in motion over the same field in the same way oscillate at the same rate. i.e. they are in *resonance*.
You have never really made an electric field. You only ever make an *oscillating* one, complete with the motion of the electron. Its has the universe oscillating resonance pattern. Since the electron is in motion, then the field it created is also oscillating with that motion.
Hence electric_oscillating force propagates per-oscillation the same as light motion is per-oscillation of that field. This is why forces appear to propagate at the speed of light.
There are no neutral particles, only sum(charged) = 0 particles. Everything is moving in the field. There is no strong force, its electric_h0, its the one and only force.
The actual *underlying* electric force propagates infinitely fast, it must, because its the only way to get the that resonance. All paths through space must take zero time, so that all paths meet together.
Space is not even. You just perceive it that way. The speed of light is not even, you only perceive it that way if you're in the same field as its traveling over. This is because you're made of matter and the scale of of your matter matter and scale of speed of light is directly related.
How to prove it.
Well, I've asked before for you to go look. Space will not be even. An anomaly in the Universe to the North will be mirrored with an opposing anomaly to the South. But that's impossible unless we are in the center of the Universe! To appear as if the anomaly is built around us, requires be at the center of everything!
We are not in the center, such a thing is ridiculously improbable. No, it's a observation effect caused by our motion over the Universe field. (This mechanism of motion where everything is motion over a oscillating resonant field). Event at universe level our motion is an oscillation over the universe resonant electric field.
aka the peasoup model, the simulation of matter as electric oscillations that may or may not still exist when Corona Virus restrictions are lifted and I can get back to my office and see if my kit has been nicked or not!