I'm curious about what is happening to phonons when the distance to the next object is further than the maximum distance at which this effect occurs.
Is there still an interaction between a hot surface and the virtual particles at the interface between the surface and a vacuum? If so, what happens to that phonon when a virtual particle it has heated is destroyed? Does that leave a net gain in the energy of the quantum flux?
I guess I'm assuming that a phonon sometimes succeeds in jumping from virtual particle to virtual particle, and sometimes has nowhere to leap when a virtual particle is destroyed.
I'd love to hear an answer, or have my assumption corrected, but right now I guess I'm just asking the universe.