Anyone who reads the web comic xkcd is probably aware that author Randall Munroe also has a site called what if? There he uses his background in physics and math (he worked at NASA in robotics for a while) to try to provide "serious scientific answers to absurd hypothetical questions." He is pretty successful while also being hilarious (so many questions result in the complete destruction of earth). Last year he published a book compiling many of the articles from the site along with new exclusive content.

If you like the site then you'll like the book. I liked both quite a bit. I'm not sure if it's worth buying or not, but it is a good way to support the mountain of amazing free content Randall Munroe delivers weekly across his two sites.