I've heard that we fear what we don't understand. By that logic, the more we understand something, the less we should fear it. To prove that this isn't true, I present to you What If?, Randall "xkcd" Munroe's attempt to scare the bejeezus out of everyone.
To be fair, I don't think it's Munroe's intention to do this. In fact, judging by the list of questions he printed that he didn't answer, he restrained from answering the questions that would have kept most people up long past their bedtimes. But considering that most of his answers end with the end of the world, the end of civilization as we know it, human extinction, or just your own death, it's not exactly something to read to your kids as a bedtime story (though I know a couple of medical doctors whose kids regularly read books about the various ways to die, so what do I know?).
The amazing thing about this book isn't that it answers these questions, but that it answers these questions in the most rational way possible. The book reads like an ode to the scientific method, and anyone with a slight interest in science as a working field of knowledge will find a lot to like in this book. In fact, much of what I found most fascinating about this book were the various factoids that were buried within these serious answers. For instance, did you know that it's possible to fill an entire stadium to the brim with ants and only account for about 1% of all the ants in the world? I didn't, that's for certain. And given that ants give me the heebie-jeebies (mostly due to my being allergic to them), I'm not entirely sure that this was something I wanted to know.
But you know what's even more amazing than that? It's that Munroe can write about these complex subjects in a way to make them perfectly understandable to laypersons. It helps that he has the background for this sort of thing (the dude used to be a NASA roboticist, after all), but that he has the ability to explain these concepts without a bunch of big words and pages and pages of math reminds me a bit of Richard Feynman. One doesn't have to have an advanced degree in math or science to understand his answers; one just has to have the curiosity to want to know more.
To me, that's what this book really is -- an ode to curiosity. Munroe opens the book with a story from when he was young and curious, and how the answer to his question shaped him as a person. Just because the logistics of his answers aren't possible doesn't mean one should stop thinking about how to solve a particular problem. As this book shows, you can learn a whole lot about other, practical things if you keep trying to figure out how to answer that impossible question.