The Nature of Light as Spiral Disturbances in the Qi Medium Framework — A Foundational Core Paper for the Model

To establish a unified cosmic medium physics system, this paper takes the nature of light as the research starting point. Based on the universal continuous Qi medium hypothesis, a core model is proposed that light is a uniform directional three-dimensional spiral ordered disturbance propagating in the Qi medium. By adopting pure geometric kinematics and elementary continuum mechanics, this study demonstrates that observed optical sinusoidal waveforms originate from the two-dimensional projection of three-dimensional spiral motion, reconstructs the self-consistent relation among light speed, wavelength and frequency, and interprets cosmological redshift via medium phase dissipation and information entropy growth. An outward-expanding spiral horn excitation model and pulse phase supplement mechanism are proposed to reveal the physical origin of optical frequency. At the receiving end, a pulse-impact decoding mechanism is established to explain the frequency dependence of the photoelectric effect without introducing photon postulation. This paper clearly distinguishes strictly deduced conclusions and unfinished contents restricted by undetermined medium parameters, defines the present theoretical boundaries and future experimental schemes, and provides solid mathematical and physical foundations for the systematic construction of Qi medium cosmic theory. Keywords: Qi medium, three-dimensional spiral disturbance, essence of light,continuum mechanics, phase dissipation, wave-particle duality