What If?: Serious Scientific Answers to Absurd Hypothetical Questions by Randall Munroe is a book based on the “What If” blog on the author’s popular web comic xkcd. Munroe is a former roboticist for NASA, who went on to write xkcd full time after his contract ended. The “What If?” blog is where fans of his comic send him questions to arbitrate ridiculous scientific debate points, such as “What would happen if you tried to hit a baseball pitched at 90% the speed of light?” and then answering such questions as completely as possible using his own knowledge, academic research, and consulting experts.

I was drawn to this book for the same reason that I loved Max Brooks’ Zombie Survival Guide. While found in the humour section, Brooks’ guide to a completely fictional scenario breaks down what means of survival would work and what wouldn’t in exceptional detail. The same goes for What If? where the humour of each question pairs wonderfully with deep scientific analysis of what would literally happen. Though this sounds clichéd, I really could laugh and learn at the same time. It’s funny to imagine trying to hit a baseball pitched at 90% the speed of light — ignoring the physical limitations that stop that from happening — and horrifying to learn the reality of what would happen. Science!

Though he breaks down the science in a rather detailed way, the writing style is lighthearted and easy to understand, as well as learn from. I found this most fortunate for some of the more math-heavy questions. Any formulas he uses toward working out an answer he presents to the reader as well. Though I can’t say I looked at them too closely, I appreciate how much he shows his work. The science is complemented by infographics and stick figure illustrations done in the style of xkcd, which also work quite well as visual aids to help explain his answers. He widely uses citations throughout his answers too. Some of these are legitimate and help explain something further when needed, others insert a quip or joke.

This may seem like a nitpick, but I wasn’t fond of the way the citations were implemented in the eBook version I read. You can touch the citation number to take you to the end of the section to read it, which is handy, but the placement of text on the book’s “pages” shifts every time you do it. This really made me wish I had a physical copy of the book, so it would be more straightforward to flip back and forth without losing my place. It was a small annoyance, but unfortunately significant enough that I was thankful whenever there were only a couple of short citations in an entry.

Between sections there are brief interludes that feature “weird and worrying questions” he’s received in the inbox, though he doesn’t answer them. They work as good little breaks between sections, though I am actually interested in hearing the answers to some of them, even if some of them are quite morbid. I suppose there wouldn’t be much scientific depth to the answer of how fast a chainsaw would have to be revving to cauterize a wound as it cuts something off, but I really want to know now.

What If? is a great book for geeks, but also anyone with an inquiring mind and a playful sense of humour (even when presented with human/global annihilation). The questions may be silly, but by giving a serious scientific answer he explains many scientific laws and principles that I was unfamiliar with before reading, and I really feel like I understand the way the universe works a little better now. Plus, you get to know what the consequences of some crazy impossibilities. It’s a book that’s great for short-burst reading if you just want to read an answer or two, but I enjoyed extended reading sessions as well. I can’t recommend it enough.