It's nostalgic to come up with geometry I did it in Mathematics III or C in Japanese education. I'm a little addicted to this book. The chapter using electromagnetism seems to be lost, but it’s attractive... (Sorry for Japanese book link 📖) It reminds me of Descartes' the Discourse on Method, but I wonder if that idea is valid in the age of data science. I think it is valid as a way of thinking...