On the Relativistic Nature of Light: From the Relativistic Interpretation of Planck’s Equation to Theoretical Estimation of Photon’s Intrinsic Properties

This study highlights a previously unnoticed peculiarity of the relativistic Doppler effect, which arises when considering the indistinguishability of photons that are identical in one reference frame but differ across others. To address this issue, the Light Intrinsic Frame of Reference (LIFOR) is proposed, defined as a specific frame where a photon is observed with its intrinsic properties, including a specific wavelength, period, and energy-equivalent-mass. The proposed theory maintains the constancy of the speed of light, aligns fully with special relativity, and explains frequency shifts via Lorentz transformations. Additionally, it provides a relativistic interpretation for Planck’s radiation energy quantization, and enables experimental quantification of photons' intrinsic properties.