Evolution of a two-dimensional foam containing a single topological defect: An experimental study

The evolution of disorder in a two-dimensional foam containing a single topological defect, a large bubble with more than six nearest neighbors, has been studied experimentally. The disorder initially grows, but those bubbles comprising the area of disorder around the central large bubble reach a stationary state in which the distribution of the coordination numbers of the bubbles and the average area per bubble are constant. This affords qualitative support to recent simulations of similar situations in two-dimensional froths; quantitative differences may arise from the wetness of the present foams.