Are you a regular reader of XKCD? Do you like hypothesizing on the fantastical? Have you considered tying yourself to 100 AK-47s and trying to fly through the air? If you answered yes to any of the previous questions then likely you would be a candidate to read What If?: Serious Scientific Answers to Absurd Hypothetical Questions By Randall Munroe. In What If? Munroe, the author of all of those amazing XKCD comics that we all quote day in and day out, attempts to answer his readers craziest questions. About half the content comes from Munroe’s What if? site https://what-if.xkcd.com/ so even if you are a regular reader there is more then enough reason to pick it up. For me, the most interesting sections were where he avoided the obvious answers like when answering the question “What if the sun disappeared?” Obviously, we would all freeze and die but think of the upsides, no solar flares, better astronomy, no time zones! It is a great gift for the nerd in your life who wants to find out if the sun actually has ever set on the British empire.