This review article discusses the concept of entropy in statistical physics and its role as both a tool for inference and a measure of time irreversibility. It highlights the developments in stochastic thermodynamics and the principle of maximum caliber, emphasizing the importance of cross-talk among researchers in disparate fields.
The second law of thermodynamics is among the most sacred in all of science, but it has always rested on 19th century arguments about probability. New arguments trace its true source to the flows of quantum information.