“...In fact, some learned folks actually admit that the speed of light and an image are not very closely related.
Working science, not absolute science. Pretty standard.” [Manly Warrior, post 15]
If the engineering folks didn’t have a pretty good idea what the speed of light is, radar would never work.
c = fl
where f is frequency, l is wavelength, and c is a constant. For electromagnetic radiation, c is the speed of light. About as absolute as anything can be, this side of Divine Perfection.
And visible light occupies only a tiny fraction of the electromagnetic spectrum.
The spectrum includes radio, radar, infrared, visible light, ultraviolet, X rays, cosmic rays (named in order of steadily increasing frequency).
No, radar and optics electronics still would work. Work is the key term.
As explained in the video, even Einstein admitted that c was a convention, a working solution. And, even today, we cannot compute the one- way value of c, except by dividing d +d1 by 2. The speed of light is an Ave age, and an average doesn’t require equality of values..... 1.75 + 1.25=3/2=1.5. but 1.5+1.5=3/2=1.5 is not the same as the former equation, although the answer is the same.
Since we cannot overcome the variables presented, like time dilation, or clock speed, we cannot using technology compute the speed of light in one direction. Therefore, c is defined by convention as 186k mi/sec and it works for our purposes, as we can clearly agree.