Unity as a Physics Simulator: Calculating Mean Free Path for Hard Disk Gas

In a typical physics course for non-physics majors, students analyze and solve problems that are simple and perceived by students as idealized to the extent that they are only remotely related to real-world problems. This perception hurts their motivation to learn fundamental physics. In this work, we show how students can use the Unity Physics Engine as a physics simulator to solve and analyze more complex and exciting physics problems than the standard paper-and-pencil problems. We provide an example of such a problem: calculating the mean free path for hard disk gas. By delegating the hard and tedious work of performing the time evolution of the system of gas particles to the Unity Physics Engine, students can concentrate on acquiring and analyzing data. In this way, students can engage with the physics of complex problems that could motivate them to learn fundamental physics. This approach to teaching physics is interesting in particular for a computer science major because it also helps students develop their programming skills.