Light is both the first messenger through which humans perceive the universe and the core research object of modern physics. From a positivist perspective, this paper demonstrates the unique status of light in the history of science: it is the only fundamental phenomenon that has run through all major revolutions and always served as the source of "observable evidence". We review the exploration of light from geometrical optics to quantum electrodynamics, pointing out that every breakthrough has never explained "why light is the way it is". Time Field Theory (TFT), for the first time, rigorously derives conclusions such as the constancy of the speed of light, Fermat's principle, and the nature of refractive index from the self-consistency of measurement benchmarks, and defines photons as "massless non-observers". On this basis, TFT makes the sharpest falsifiability commitment: if future experiments find any change in the vacuum speed of light, TFT will directly accept falsification and never add ad hoc parameters. This paper argues that this attitude of "betting everything on the honesty of light" is precisely the dignity that a scientific theory should have. This is a preprint of the Time Field Theory (TFT) series. All conclusions are strictly derived from first principles without additional ad hoc assumptions.
Huowang Huang (Sun,) studied this question.