Michael Cavna in The Washington Post:
Imagining such a hypothetical sparks the ever-curious mind of Randall Munroe, the brain behind the webcomic “xkcd” — beloved by math and science geeks the unpainted globe over — who also answers readers’ bizarre and quirky queries on his blog. His replies yielded the best-selling 2014 book “What If?: Serious Scientific Answers to Absurd Hypothetical Questions.” This week, the Massachusetts-based author follows that up with the equally entertaining “What If? 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions,” which combines Munroe’s true research and truly funny prose with his signature stick-figure illustrations.
More here.