Taking Plateau into Microgravity: The Formation of an Eightfold Vertex in a System of Soap Films

The microgravity phases of parabolic flights were used to perform experiments with soap films trapped in wire frames, a variation of the wire frame experiments originally designed by the nineteenth century Belgian scientist Joseph Plateau. We considered the formation of an eightfold vertex of Plateau borders within a cubic frame. In terrestrial experiments such a vertex can only be formed when liquid is forced through the Plateau borders, but in microgravity we found this vertex to be stable under equilibrium (non-flow) conditions once the liquid volume fraction exceeds 0.022 ± 0.005. This is consistent with the theoretical value for the transition, which for our experiment we estimate to be 0.0192.