  Charged systems interacting via Coulomb forces can be efficiently simulated
by introducing a local, diffusing degree of freedom for the electric field.
This paper formulates the continuum electrodynamic equations corresponding to
the algorithm and studies the spectrum of fluctuations when these equations are
coupled to mobile charges. I compare the calculations with simulations of a
charged lattice gas, and study the dynamics of charge and density fluctuations.
The algorithm can be understood as a realization of a mechanical model of the
ether.
