Let’s define simulation as a prediction of real-world events (think of something you cannot or don’t want to measure or something you’d like to explore before actually building it). So why bother when there’s already reality to look at?
Here are a few reasons I can come up with:
- We want something that feels like reality (special effects in a movie or a physics engine in a video game)
- We want to test a physical system before actually building it (e.g. design simulations in engineering)
- There’s something we’d like to know we cannot easily measure (think of the inside of reactors and high-power turbines – or complex systems like sociology or medicine where we try to infer on hidden variables to estimate treatment effects)
- We’d like to understand something about reality and do so by building a model of it.
The last point above is a little bit obscure and I’d like to elaborate. Actually, this is my favorite reason for spending free time with simulation (in contrast to paid time at work which is all about 1-3): I’d like to learn something about reality!