Chaos, by James Gleick. It's somewhere between biography and science for laypeople. Almost a biography of an idea. What he wrote about the edges of science and how scientific rebels think about their fields blew my mind when I read it in my teens, and it started the closest thing to a religion that has taken hold in my mind: a kind of Pantheist vision of how a fully deterministic universe can lead to an infinite, confusing, and beautiful world, with mathematical inevitability and precision rather than by some kind of magic.