A Brief History of Time written by Hawking can be read.
Adventures in the physical world, telling the principles and explanations of some physical phenomena.
Relativity is famous, you know.
In mathematics, if you want to delve into it, you can look at advanced mathematics or engineering mathematical analysis, and then look at mathematical analysis and so on. "A Brief History of Mathematics", "Romance of Mathematics" and "General Theory of Mathematical History" are relatively simple ... If you want to understand mathematics in a popular way, you can read them.