
I’m a confirmed fan of XKCD but I’ve never really got into What If. However, I was given the book for Christmas and I’m glad that I was because I really enjoyed it. I love the way that Munroe takes, as it puts it on the cover, absurd hypothetical questions, and answers them in a really methodical way and the gleeful way he adds more power until he gets really big explosions.
I was surprised by just how readable the book was. I fairly flew through it in a couple of days, when I was expecting to read one or two questions a day. Munroe is very good at balancing his answers between science and entertainment (the cartoons, captions and footnotes definitely helping with the latter). The explanations are always clear and delivered with the minimal amount of maths required to make it make sense, although he never shies away from the maths. This is a guy who knows his audience and never talks down to them.
This is a book not just for fans of XKCD, but for anyone who kept (or, indeed, still keeps) asking ‘why’. Anyone who’s spent time mulling over questions that other people think are silly or pointless. Munroe not only takes such questions seriously but he answers them, and will extrapolate it until he can make something explode [Citation needed].