Film spreading on interfaces
The  influence of surface tension at an air-water interface induces mesmerizing flow patterns on the air-water interface.

Instabilities at an interface.
As the ethanol film spreads over the surface of the water,  the film undergoes azimuthal instability, giving rise to evenly spaced, radially expanding plume-like structures along its outer edge. Shortly after the appearance of these plumes, the film ceases its expansion and begins to retract.