Dimensional analysis is one of my favorite subjects. Unfortunately the more advanced results from it are rarely taught outside of fluid dynamics classes, e.g.:

Dimensional analysis is one of my favorite subjects. Unfortunately the more advanced results from it are rarely taught outside of fluid dynamics classes, e.g.: https://en.wikipedia.org/wiki/Buckingham_%CF%80_theorem https://en.wikipedia.org/wiki/Buckingham_%CF%80_theorem The pi theorem is one of the most useful results in my work as a theoretical fluid dynamicist. The (modest) dimensionality reduction it offers seems unbelievable at first.