Cosmology, philosophy, religion, and a brilliant mind come together in the book which at times is as easy to read as that quote and at other times tough going. It's a good balance. Lightman makes tough concepts available to a pedestrian science reader such as myself. Here he describes a Planck length:

That ratio bit floors me. I still can't imagine that infinitesimal size, but I have an idea of it now. 

This is what LIghtman does throughout as he discusses faith and science, absolutes and relatives. He suggests the beginnings of the universe then questions if such a thing could begin. He touches on quantum mechanics where particles cannot be located in space because they tend to be in two places at once. I don't understand these things as often as I would like, but by the end of the book, like the end of a good class, I understand much more and I want to keep going. 

The book is really about what it is to be human and leads me to believe that to be human is to raise questions, probe the answers, and follow these into more wondering. The universe, whatever it may be, is a place of wonder and Lightman wonders as well as anyone.