The size and shape of photons are still unknown. Due to their dual wave–particle quantum nature and recent discoveries related to entanglement, photons continue to surprise the scientific community. The ability to generate single pure photons opens up many potential applications, particularly in information technology. On the other hand, thermal photons are encountered in everyday life. Environmental effects, material reliability, and aging under high temperature are all areas where thermal photons play an important role. Engineers must understand better the effects of these photons. By applying Einstein’s law relating photon energy to frequency, using Maxwell’s classical electromagnetic laws and the Poynting theorem concerning electric fields, it becomes possible to link the wave and particle aspects of photons. These relations suggest that a photons volume (considered as semi-classical volume) is proportional to the cube of its wavelength. By combining Planck’s law, the Poynting power law, and Bose–Einstein statistics, one can estimate both the volume and electric field of thermal photons as functions of frequency. These values can then be correlated with the physical effects photons have on matter.
Alain Toureille (Mon,) studied this question.