ORDER AND COHERENCE - A QUESTION OF SIZE FOR MATTER AND RADIATION

Structural and ferromagnetic order and coherent radiation are radicall y different observations that suggest the consideration of the effects of a critical minimum size as a common principle. The conceptually di fferent models of discreteness and continuum have been mutually exclus ive to this day, but there seems to be an intermediate (mesoscopic) ra nge of system sizes where the two blend together. The deep analogy bet ween massive particles and zero rest mass boson particles is of partic ular interest for the still intriguing problem of the evolution of a c lassical electromagnetic wave from an ensemble of photons. This revers es the paradigm of quantum field theory, according to which photons ar e quanta of free fields. Photons emitted from (complex) atomic sources organize themselves into an electromagnetic wave. Discrete matter rat her than the field is thus primordial.