Quantum particle, light clock or heavy beat box?

A standing wave of light inside a cavity, while observed from a moving frame, is seen to have a spatial beat of precisely the same nature as that of the de Broglie wave of a quantum particle. The structural forces that hold together the cavity against the internal radiation pressure are compared to the so-called Poincaré stresses inside an elementary particle, as are required for the particle's stability. This seems to work best if the cavity is non-rigid and hence is itself oscillating, coupled to the radiation inside. (paper)