In an information age where a primary challenge is to extract insight and meaning from mountains of data statistical physics is an essential tool. The natural world is built with many small components interacting in a simple but coordinated way. With a probabilistic view, we may make sense of the cooperative phenomena which emerge. We can associate thermodynamic free energies with microscopic states. With calculations and simple numerical exercises we shall probe a wide variety of physical phenomena: magnetism, gasses, heat engines, thermal radiation, electrons in solids, polymers, random walks in fluids or in the stock market, and genomic information. Format: lecture/discussion, three hours per week. Evaluation will be based on weekly problem sets, quizzes, and a final exam. Prerequisites: Physics 142, Physics 210. No enrollment limit (expected: 15).