By "numerical," I mean that I'll create a python program that models the motion of light from A to B. I will then change the reflection point on the surface until I get the smallest travel time.

“Python’s extensibility and interoperability with other programming languages and numerical libraries makes it an increasingly popular choice in both the financial and scientific computing ...

Physics and Python stuff. Most of the videos here are either adapted from class lectures or solving physics problems. I really like to use numerical calculations without all the fancy programming ...

Numerical calculations are grand. Of course, they are just another form of normal calculations - like I have said before.