How Much of Nature Can We Deduce From Mathematics?

I feel like when you're dealing with speed of light kind of stuff and a doubly so cosmology, you have that kind of effect where almost the subject matter is slipping away from you. So I've always been fascinated by the question, how much of nature can we describe by mathematics? How much can it do for us? And you find this in several places in my new book. That's why I partly wrote this book to remind myself of why I was interested in that question and why I find it so fascinating that physics can tell us all those things,. which we in a very concrete way pretty much deduce from mathematics.