Microscopic Scale
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A characteristic feature of the dynamical network models we investigated is their [undulatory]{} character. As a consequence of the [feedback]{} structure of the coupling between node (cell) states and [wiring diagram]{} of edges (i.e. the pattern of momentary elementary connections or interactions) the network never settles in a static, frozen final state. The network may of course end up in some [attracting]{} subset of phase space but typical are wild fluctuations on a small (microscopic) scale with possibly some macroscopic patterns emerging on a coarser scale forming some kind of [superstructure]{} (see e.g. [@R4]).

It is in our view not sufficiently appreciated that, in contrast to most of the other systems being studied in physics, the quantum vacuum is in a state of eternal unrest on a microscopic scale, with, for all we know, short-lived excitations constantly popping up and being reabsorbed by the seething sea.

It therefore seems reasonable to regard our above network model (investigated in e.g. [@R1] to [@R4]) as a (toy) model of the quantum vacuum with the energy-momentum fluctuations on short scales being associated with the fluctuations of the local node and edge states.

In the following we adopt the working hypothesis 