  We review methods developed in the gauge-string duality to treat energy loss
by energetic probes of a strongly coupled thermal medium. After introducing the
black hole description of the thermal medium, we discuss the trailing string
behind a heavy quark and the drag force that it implies. We then explain how to
solve the linearized Einstein equations in the presence of the trailing string
and extract from the solutions the energy density and the Poynting vector of
the dual gauge theory. We summarize some efforts to compare these calculations
to heavy ion phenomenology.
