Book: What If?

Did some book shopping yesterday and ran across this new book by Randall Monroe, the mad scientist behind the webcomic XKCD.  The book's subtitle is "Serious Scientific Answers to Absurd Hypothetical Questions" -- questions like "What would happen to the earth if everyone jumped at once?" or "What would happen if you tried to assemble a physical table of the elements using every element on it?" or "What would happen if the Earth stopped spinning but the atmosphere didn't?"

The answers are funny, and deeply knowledgable, and really weird.  I can't put it down.

One of the scenarios the author covered was figuring out approximately how much force Yoda exerted in pulling Luke's X-Wing fighter out of the swamp on Dagoba. Turns out it's about the horsepower of a SmartCar.