Why Light Appears to Carry Momentum: Radiation Pressure as a Direct Manifestation of the SP3 Space-Phase Field Equations

The momentum of light is classically demonstrated by radiation pressure experiments inwhich a vane suspended in vacuum rotates under illumination. In standard physics, thiseffect is attributed to momentum carried intrinsically by photons. In this paper, the samephenomenon is reinterpreted within the SP3 (Space-Phase, Saturation, and Memory)framework. SP3 does not deny the experimental outcome; instead, it reframes momentumas an emergent mechanical response arising from the interruption of coherent space-phasetransport by matter. Light is treated as a propagating coherence structure within spacephase rather than as a stream of point particles carrying momentum. When this coherenttransport is disrupted by a material boundary, phase-continuity enforcement produces areaction force that manifests macroscopically as radiation pressure.