# Chapter 4: Methodology

We combine ideas from thermodynamics and probability theory to introduce *statistical mechanics*, which is the study of how microscopic behavior leads to macroscopic behavior in systems of many constituents. There only are a few models, such as the ideal gas whose macroscopic averages can be calculated analytically starting from the microscopic model.

In this chapter we use the computer to illustrate the counting of microstates and the behavior of some many particle systems.

## Programs

- Program 4.1: Einstein Solid Microstates
- Program 4.2: Einstein Solid Entropy
- Program 4.3: Counting States
- Program 4.4: Demon Ideal Gas
- Program 4.5: Demon Einstein Solid
- Program 4.6: MC Einstein Solid
- Program 4.7: Hard Disks MD