nonequilibrium statistical mechanics

Nonequilibrium statistical mechanics studies how large systems of particles behave when they are not in thermal equilibrium, meaning their properties (like temperature, pressure, or density) change over time or are unevenly distributed. It helps us understand processes such as heat flow, diffusion, and chemical reactions. Instead of analyzing individual particles, it uses statistical methods to describe the collective behavior of many particles, providing insights into how systems evolve toward equilibrium or respond to external forces. This field bridges microscopic interactions with macroscopic observations in dynamic, real-world systems.