ELI5: Explain Like I'm 5

Direct simulation Monte Carlo

Direct Simulation Monte Carlo (DSMC) is a way of trying to figure out how things move in a gas. It uses something called a computer simulation. Basically, DSMC looks at a gas and pretends there are lots of little particles inside it, and tries to figure out how they move and bump into each other. It's like a virtual experiment that lets us see what's going on inside the gas.