Multiscale Entropy and Its Implications to Critical Phenomena, Emergent Behaviors, and Information

Thermodynamics of critical phenomena in a system is well understood in terms of the divergence of molar quantities with respect to potentials. However, the prediction and the microscopic mechanisms of critical points and the associated property anomaly remain elusive. It is shown that while the critical point is typically considered to represent the limit of stability of a system when the system is approached from a homogenous state to the critical point, it can also be considered to represent the convergence of several homogeneous subsystems to become a macro-homogeneous system when the critical point is approached from a macro-heterogeneous system. Through the understanding of statistic characteristics of entropy in different scales, it is demonstrated that the statistic competition of key representative configurations results in the divergence of molar quantities when metastable configurations have higher entropy than the stable configuration. Furthermore, the connection between change of configurations and the change of information is discussed, which provides a quantitative framework to study complex, dissipative systems.