  Long range interactions are relevant for a wide range of phenomena in physics
where they often present a challenge to theory. In condensed matter, the
interplay of Coulomb interaction and disorder remains largely an unsolved
problem. In two dimensional films the long-range part of the Coulomb
interaction may be screened by a nearby metallic overlay. This technique is
employed in this work to present experimental evidence for its effectiveness in
limiting the spatial range of the Coulomb interaction. We use this approach to
study the effects of the long-range Coulomb interaction on the
out-of-equilibrium dynamics of electron-glasses using amorphous indium-oxide
films. The results demonstrate that electronic relaxation times, extending over
thousands of seconds, do not hinge on the long-range Coulomb interaction nor on
the presence of a real gap in the density of states. Rather, they emphasize the
dominant role played by disorder in controlling the slow thermalization
processes of Anderson insulators taken far from equilibrium.
