It's a new year, with new lectures. Today is an introduction to Thermal and Statistical Physics. We do a lightning-fast review of quantum mechanics, aided by the excellent program Atom in a Box available at www.daugerresearch.com. We also discuss the fundamental assumption of statistical mechanics. Although statistical mechanics is based on probabilities about processes on very small (atomic) scales, we can still make firm predictions about large-scale behavior. This works for the same reason that casinos make money: the statistics of large numbers becomes deterministic. Lecture Audio