I don't read much fiction (it's all made up, you know) but I do read a lot and I appreciate good writing. On that basis, here are three "popular science" paperbacks I strongly recommend to anyone with more than a passing interest in physics, mathematics or evolution:
The Magic Furnace by Marcus Chown;
Imagining Numbers: (Particularly the Square Root of Minus Fifteen) by Barry Mazur;
In the Blink of an Eye: How Vision Kick-started the Big Bang of Evolution by Andrew Parker.
By the way, that last one is a must for anyone who's been engaged in debate by Creationists who can't understand how something as complex as the eye could ever have evolved. If they only knew.