Inertia from radiation. A semiclassical approach

Abstract Starting from a thought experiment based on an accelerated reflecting cavity containing a radiation bath, the cavity-radiation dynamical interaction is evaluated. The radiation is considered as a monochromatic flux of photons that bounces forwards and backwards in the direction of acceleration. In this case, in each reflection, the delay originating from the time of flight of photons causes a difference in velocity between the receiving and emitting reflecting faces at the opposite ends of the cavity, and consequently, a Doppler shift. Despite the ends of the cavity being at rest relative to each other, this phenomenon generates a difference of radiation pressure between both ends, which acts as the inertia of the radiation bath and verifies Newton’s 2nd Law for non-relativistic conditions. This result has interesting implications for the current theoretical pictures of dynamical properties of photons.