Study of Non-equilibrium Phenomena by Visualization Technique

Abstract

Nonequilibrium phenomena can be ubiquitously seen in nature and daily lives. Comparing with equilibrium states where physical properties are defined by thermodynamical conditions, dynamical paths are the most important for the nonequilibrium phenomena. Thus, visualization technique is one of the most crucial methods for understanding of the nonequilibrium phenomena. Here we introduce two equilibrium phenomena. The first one is a collective collapse of a foam. When a liquid film is punctured, a liquid droplet is emitted. In addition, the emitted droplet punctures a distanced liquid film and then the collapse occurs collectively. The other example is a gravitational instability of fluids. We use a physical gel as a lower layer in order to sustain a heavy upper layer. When we heat the sample rapidly, the physical gel is fluidized. Then the instability starts to occur. It makes us to observe the instability from the beginning without any artificial perturbation.