This is a wonderful book by Randall Munroe that was loaned to me by a Grandson who correctly judged that I would be impressed. I was so impressed that I bought copies for other grandchildren and friends. It is easy for someone to learn whether they would enjoy the book by checking out Munroe’s xkcd.com web site. He says that just over half of the questions analyzed in the book are new and that the rest had been posted on the web site. Munroe, who has an obviously strong background in physics, uses clever descriptions and illustrates the book with stick figure drawings.

The book presents detailed scientific answers to questions people have posed to Munroe. As to the accuracy or wisdom of the answers, the disclaimer exhorts, “Do not try any of this at home. The author of this book is an Internet cartoonist, not a health and safety expert. He likes it when things catch fire or explode, which means he does not have your best interests in mind.” I found the frequent humor to be a wonderful addition to the often serious science being discussed. One person had asked “What if I took a swim in a typical spent nuclear fuel pool?” Munroe discusses the question and concludes that you’d be safe as long as you didn’t dive to the bottom of the pool and pick up something. He decided to check with a friend who works at a research reactor. The answer was, “You’d die pretty quickly, before reaching the water, from gunshot wounds.”

As another example of the humor, there are many instances where a very obvious fact is stated followed by a note that a citation is needed. One sentence states “The Sun is really bright, ^{(citation needed)} and its light illuminates the Earth. ^{(citation needed)}

I’m going to list some of my favorite questions with a brief summary of the answers:

• “What would happen if you made a periodic table out of cube-shaped bricks, where each brick was made of the corresponding element?” The answer gives a good description of the periodic table and goes though each row. On the sixth row, “No matter how careful you are, the sixth row would definitely kill you…The seventh row would be much worse.”
• “What would happen if everyone on Earth stood as close to each other as they could and jumped, everyone landing on the ground at the same instant?” The orbit of the Earth is unaffected, but most of its inhabitants will die because there isn’t enough food and water available to support the billions of people who have gathered at one location. A few will be lucky enough to steal a car and escape.
• “Is it possible to build a jetpack using downward-firing machine guns?” This is probably one of the most popular of the questions. One AK-47 probably would create enough thrust to take off with a squirrel clinging to it. A properly designed craft powered by the Russian Gryazev-Shipunov GSh-6-30 could jump mountains because of the extremely high rate of fire.
• “How long could a nuclear submarine last in orbit?” I include this question because the word “apricity” shows up in the answer. A footnote explains, “This is my single favorite word in the English language. It means the warmth of sunlight in winter.”
• What would happen if you set off a nuclear bomb in the eye of a hurricane?” The National Oceanic and Atmospheric Administration has considered the question and reached the conclusion, “Needless to say, this is not a good idea.”
• There are many other clever questions and answers, but I’ll close with one of my favorites. “How quickly would the oceans drain if a circular portal 10 meters in radius leading into space were created at the bottom of Challenger Deep, the deepest spot in the ocean?” Munroe calculates “…if an aircraft carrier sank and got stuck against the drain, the pressure would easily be enough to fold it up and suck it through. Cooool.” Munroe decided the outlet for the drain would be above the Curiosity rover on Mars. He provides sketches of Earth as the oceans drop first fifty meters and finally five kilometers. The only water remaining will be inland seas and a few trenches. Munroe cleverly predicts that the Netherlands will begin claiming newly exposed coast line until they have claimed most of Earth. Only a few tall peaks with remain above water on Mars and Munroe predicts Netherlands will claim the entire planet.

There are entertaining “Weird (And Worrying) Questions” that usually provide no answers scattered through the book. An example of a thoughtful question is, “If global warming puts us in danger through temperature rise, and super-volcanoes put us into danger of global cooling, shouldn’t those two dangers balance each other out?” An example of a scary question is, “How fast would a human have to run in order to be cut in half at the bellybutton by a cheese-cutting wire?”

Both my grandson and I noticed no explanation of the picture on the cover of a tyrannosaurus being lowered into a Sarlaac pit. The Sarlaac of Star Wars fame is mentioned on page 178 when one of the stick figures discussing how long a Venus fly trap would take to absorb a human mentions, “And I bet Boba Fett was chewing gum when the Sarlaac ate him.” There are explanations about Boba Fett and the Sarlaac on Wookieepedia (absent the reference to gum).

Check out the book and be prepared to be entertained, educated, and challenged.