The Recursive Microstates model considers an isolated system consisting of N identical, non-interacting quantum particles.  The model displays the total number of microstates accessible to the system with energy E.  A second windows displays the entropy S(N,E).

For fixed total energy E, the model computes the number of microstates by considering a system of N distinguishable particles to be composed of a subsystem of N - 1 particles and a subsystem of 1 particle. The number of microstates is then constructed by summing the number of ways in which the subsystem of N -1 particles can configure itself with energy E <= E' weighted by the degeneracy of the single particle level with energy E?.

The Recursive Microstates model was developed by Wolfgang Christian, Trisha Salagaram, and Nithaya Chetty using the Easy Java Simulations (EJS) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking the  ejs_stp_RecursiveMicrostates.jar file will run the program if Java is installed.

Please note that this resource requires at least version 1.5 of Java.