<b>The Impact of Orbital Angular Momentum on Photon Velocity and Spectroscopy</b>

This brief explores the idea that <b>photons carrying orbital angular momentum (OAM) must allocate part of their energy to rotational motion</b>, which in turn reduces their effective forward velocity. The argument follows from basic energy conservation and momentum relations, without requiring wave-particle duality, quantum field effects, or spacetime distortions. The consequences of this are:<b>OAM Requires Energy</b> – Rotational motion inherently stores energy, which must come from the photon's fixed energy budget.<b>Velocity Reduction</b> – If part of the photon's energy is allocated to OAM, less is available for linear propagation, meaning its velocity must be slightly lower than ccc.<b>Momentum Transfer</b> – Since momentum depends on velocity, OAM alters how photons transfer momentum upon interaction.<b>Spectroscopy Implications</b> – Spectrometers measure momentum and energy, not velocity. This means OAM-induced velocity changes could cause systematic spectral shifts that may be misclassified as Doppler or gravitational redshifts.<b>Experimental Considerations</b> – Testing this requires comparing structured (OAM) and non-structured light under controlled conditions to detect systematic spectral shifts linked to OAM modulation.