If you know what New Scientist is like and what these books are like, this is more of the usual. People ask their strange or not-so-strange questions about topics scientific, and other people chip in with what they know. Where one answer didn’t quite cover all the angles, another one is often included. You’ll notice folks like David Muir of Portobello High School answering a lot of questions, while others are answered by people who happen to work in something related or had that curiosity themselves and carried out experiments. Sometimes the questions are interesting, sometimes less so — and sometimes the answers are satisfying, and sometimes they’re not quite enough.
It’s an excellent source of general science knowledge, and a good type of book to dip in and out of casually. I did notice that some of the answers are also included in at least one of the New Scientist collections, which I guess is to be expected.