Dynamics of density fluctuation of supercritical fluid mapped on phase diagram.

A time evolution of polar molecules inhomogeneously dispersing in mesoscale is investigated by dynamic light scattering around the gas-liquid critical point. The dynamics evaluated on phase diagrams produces a contour map of critical slowing down and suggests a ridge to be a trace of intermediate lines between gas and liquid states. A good coincidence between dynamics and static inhomogeneities is confirmed in the wide density, and it is consistent with theoretical expressions.