Uh huh.
Agreed. But we are looking back in time, just at light emitted by an object far away.
A review of how the speed of light is derived is an interesting convention. An agreed upon working solution. 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.
“...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).