I was fascinated by this book, and in many ways it presents a revolutionary picture of life in the solar system based on solid science, such as the recent discoveries that may show life on earth originated deep under the surface, which implies that life could have originated without a planetary surface that was juuuuuust right. But as a physicist I'm disturbed by the way Davies cavalierly throws around the authority of physics in a manner calculated to impress and mystify. I can't help thinking that his fancy footwork with information theory is a matter of the emperor's new clothes. Certainly my PhD in physics didn't help me to decode some of this stuff, which is not a good sign for a book supposedly aimed at a general audience. I can't understand his aversion to the idea that life might have evolved independently on Mars or Europa, and I'm puzzled by his refusal to believe in a materialistic basis for life. To his credit, he does a fairly good job of pointing out which of his ideas are (to put it charitably) speculative.