Nonequilibrium statistical mechanics: A solvable model

A two-temperature linear spin model is presented as an introduction to nonequilibrium statistical physics. The model involves the concepts that are typical of more realistic nonequilibrium models, but has straightforward steady state solutions and, for small systems, development of the full time dependence for configuration probabilities. The model is accessible to upper-level undergraduates and provides a good check of computer models for larger systems.