XKCD author and former NASA roboticist Randall Munroe has been running a blog called What If? to answer his readers' strange scientific questions with equally strange scientific answers for almost two years now, and later this year he'll be turning the blog into a book. The book, What If?: Serious Scientific Answers to Absurd Hypothetical Questions, will be published on September 2nd and, according to The New York Times, about a third of it will be composed of new questions that haven't been posted online. Munroe says that the new entries are "particularly neat questions that I wanted to spend a little more time on," and that some older articles have been revised and updated too.
Munroe's What If? articles generally begin with a question that few have wondered about — such as "Has humanity produced enough paint to cover the entire land area of the Earth?" and "Is it possible to build a jetpack using downward firing machine guns?" — and then answer it with surprising scientific rigor, often to absurd conclusions (for instance: a machine gun might not work as a jetpack, but an aircraft anti-tank gun would get you a lot closer). His famous stick-figure cartoons illustrate the absurd scenarios discussed throughout What If? as well. While Munroe's background in physics certainly comes in handy, he tells the Times that there's a lot of additional research involved in running the blog: "Doing What If? has gotten me doing more science research than I did for my degree."