  Dynamic jamming is a phenomenon whereby a dense suspension switches from a
fluid-like to a solid-like state when subjected to sufficient stress and
deformation. Large enough systems show that this transition is accompanied by a
distinct jamming front. We present an experimental study where two jamming
fronts are created simultaneously using two cylinders moving in parallel. We
focus our observations on the collision of the jammed regions when the two
fronts meet. Surprisingly, our measurements, combining surface texture
visualization and time-resolved particle image velocimetry, show the formation
of an unjammed region contained within the otherwise jammed suspension.
