Extremely accessible, appropriately amusing, and very informative. I am really enjoying the book and can say that Bill Bryson's understated wit is very engaging. It's quite a dense book with lot of information, very approachable examples, and a bit of humor sprinkled throughout. I was impressed with the overall format, content, and presentation and highly recommend the book to anyone with an interest in the world around them. Definitely one of the best Science books around.