Figure 1
C. Yang et al., Phys. Rev. Lett. (2012)

On the move. A digital representation generated from real photos of a two-dimensional liquid made of beads floating in a plasma. A bead is at each vertex, and the colors represent the amount of rotation each “bond” experienced during a 7-second period. Small triangles and squares indicate beads with five and seven neighbors, respectively, rather than the usual six. The beads assemble into ordered patches, separated by boundaries that are constantly torn and repaired as the patches move and rotate.