  Focusing a finite amount of energy dynamically into a vanishingly small
amount of material requires that the initial condition be perfectly symmetric.
In reality, imperfections are always present and cut-off the approach towards
the focusing singularity. The disconnection of an underwater bubble provides a
simple example of this process. An initial asymmetry in the shape of the bubble
neck excites vibrations that persist over time. Often the vibrations evolve
into a smooth contact that severs the neck into several lobes.
