This is by far one of the best science books for the layman I have ever read, and I enjoyed reading it. I especially liked the discussions of the cultural context inwhich Copernicus, Kepler, Galileo, and Newton worked. The break that Copernicus made with common sense AND religous dogma is so great as to boggle the mind even today. And Kepler's determination that the Earth's orbit is an ellipse, again defies belief, since it was done before calculus was invented, or the law of Gravity determined.
I highly recommend this book to anyone who enjoys a good science read.