This review applies to MOST of the Basher books as they all seem to share the same mix of excellence and failure.
First, these books are GREAT in that they present some of the terminology/jargon of the subject matter in a way that seems to interest small children! (in my experience, ages 4-7 seems about right) This is actually a BIG DEAL, as the books reliably deal in wonderfully important subjects. For this, I highly recommend them and thank the authors and publishers for their effort!
However... there are two ways in which I find these books to be terribly disappointing:
1) The attempts to make each entry clever and fun raise the effective reading level high above the target audience. Clever puns and delightfully descriptive diatribes do not go over so well with young children just beginning to read. My six year old is completely ready for the subject matter, but struggles to the point of giving up (!!) trying to manage the prose.
2) IMHO, the attempts at fun language and clever characterizations often work to obscure the simplicity of the subject matter at hand. As a scientist who understands many of the concepts under discussion, I often find myself marveling at how these descriptions express an opaque and incomprehensible version of what are fundamentally simple ideas.
Basher Guys... I LOVE what you are trying to do. IMHO, if you can find a way to simplify the prose, and not let "characterizations" get in the way of "simple explanations", then you will be changing the WORLD!!
So despite my reservations... BUY THESE BOOKS!... I think that as long as they use it to try to do better, these guys have TOTALLY earned our income!!