  For over twenty years the possibility that the electromagnetic zero point
field (ZPF) may actively accelerate electromagnetically interacting particles
in regions of extremely low particle density (as those extant in intergalactic
space (IGS) with n < 1 particle/m^3 has been studied and analyzed. This
energizing phenomenon has been one of the few contenders for acceleration of
cosmic rays (CR), particularly at ultrahigh energies. The recent finding by the
AGASA collaboration (Phys. Rev. Lett., 81, 1163, 1998) that the CR energy
spectrum does not display any signs of the Greisen-Zatsepin-Kuzmin cut-off
(that should be present if these CR particles were indeed generated in
localized ultrahigh energies CR sources, as e.g., quasars and other highly
active galactic nuclei), may indicate the need for an acceleration mechanism
that is distributed throughout IGS as is the case with the ZPF. Other
unexplained phenomena that receive an explanation from this mechanism are the
generation of X-ray and gamma-ray backgrounds and the existence of Cosmic
Voids. However recently, a statistical mechanics kind of challenge to the
classical (not the quantum) version of the zero-point acceleration mechanism
has been posed (de la Pena and Cetto, The Quantum Dice, 1996). Here we briefly
examine the consequences of this challenge and a prospective resolution.
