"Delightful. . . Randall Munroe has made a career out of sharing his joy in science and engineering. . . . This book and its predecessor inspire us to believe that, even in a vast and mysterious universe, there's a lot we can figure out with nothing but a sharp pencil, come basic scientific knowledge and a vivid imagination." --The Wall Street Journal

"The questions throughout What If? 2 are equal parts brilliant, gross, and wonderfully absurd and the answers are thorough, deeply researched, and great fun. . . . Science isn't easy, but in Munroe's capable hands, it surely can be fun." --TIME

"Picking this book up now and then enlivens life by letting you briefly consider the effects of, say, putting an indestructible 20-meter-wide glass tube all the way down to the deepest part of the ocean. Plus, Munroe's illustrations turn stick figures and flowcharts into the stuff of existential hilarity." --NPR

"Entertaining. . . . combines Munroe's true research and truly funny prose with his signature stick-figure illustrations." --The Washington Post

"Perfect if you enjoy it when stuffy figures of authority crack a smile. Or if you like it when black holes form. That happens a lot." --Newsweek

"One of my favorite books of the year." --Tim Harford, Financial Times

"It's an absolute delight! It's the coolest way to learn how the world actually works." --Hank Green (on the Dear Hank & John podcast)

"A delight for science geeks with a penchant for oddball thought experiments." --Kirkus

Praise for Randall Munroe and What If?

"Randall Munroe is a national treasure." --Phil Plait

"Extreme astrophysics and indecipherable chemistry have rarely been this clearly explained or this consistently hilarious." --Entertainment Weekly "10 Best Nonfiction Books of the Year"

"Consistently fascinating and entertaining...Munroe leavens the hard science with whimsical touches... An illuminating handbook of methods of reasoning." --Wall Street Journal

"It's fun to watch as Munroe tackles each question and examines every possible complication with nerdy and methodical aplomb.... The delightfully demented What If? is the most fun you can have with math and science, short of becoming your own evil genius." --Boston Globe