@Ignatz, thinking about it then there’s quite a lot of mathematics in there:
- Basic geometry: using and manipulating vectors to position the bowl and fish.
- Transformations: transforming the fish’s position to “bowl coordinates” and back again, and the formula for a reflection in a line.
- Newtonian Mechanics: working out the forces on the fish and
F = m a
to figure out the effect on the fish. - Euler Step-by-step: numerical method for solving a differential equation.
- Calculus: how to figure out the normal vector for an ellipse.
I could probably get a whole text book out of that simple example …