How To

How to Catch a Drone
A wedding-photography drone is buzzing around above you. You don t know what it s doing there and you want it to stop.

Let s suppose you have a garage full of sports equipment baseballs, tennis rackets, lawn darts, you name it. Which sport s projectiles would work best for hitting a drone? And who would make the best anti-drone guard? A baseball pitcher? A basketball player? A tennis player? A golfer? Someone else?

There are a few factors to consider accuracy, weight, range, and projectile size.

One sport I couldn t find good data on was tennis. I found some studies of tennis pro accuracy, but they involved hitting targets marked on the court, rather than in the air.

So I reached out to Serena Williams.

To my pleasant surprise, she was happy to help out. Her husband, Alexis, offered a sacrificial drone, a DJI Mavic Pro 2 with a broken camera. They headed out to her practice court to see how effective the world s best tennis player would be at fending off a robot invasion.

The few studies I could find suggested tennis players would score relatively low com- pared to athletes who threw projectiles more like kickers than pitchers. My tentative guess was that a champion player would have an accuracy ratio around 50 when serving, and take 5 7 tries to hit a drone from 40 feet. (Would a tennis ball even knock down a drone? Maybe it would just ricochet off and cause the drone to wobble! I had so many questions.)

Alexis flew the drone over the net and hovered there, while Serena served from the baseline.
Her first serve went low. The second zipped past the drone to one side.

The third serve scored a direct hit on one of the propellers. The drone spun, momentarily seemed like it might stay in the air, then flipped over and smashed into the court. Serena started laughing as Alexis walked over to investigate the crash site, where the drone lay on the court near several propeller fragments.

I had expected a

Randall Munroe is the author of the New York Times bestsellers What If? 2, How To, What If?, and Thing Explainer; the science question-and-answer blog What If?; and the popular web comic xkcd. A former NASA roboticist, he left the agency in 2006 to draw comics on the internet full time. He lives in Massachusetts.

The creator of the popular, extremely excellent and not a little nerdy webcomic xkcd cleverly illustrates a guide of complicated solutions to simple tasks, thinking up Rube Goldbergian solutions to tasks as common as digging a hole. USA Today

The mind behind the webcomic xkcd provides a slew of hilariously overcomplicated instructions for everything from throwing a pool party to winning an election, bringing his signature stick figures and his singular wit along for the ride. How To is a loving testament to the power of the human brain to take things to absurd lengths. Glen Weldon, NPR

[How To] tackles problems from the mundane such as how to move to a new house to those that may trouble a mad scientist building her first lava moat. The solutions are often hilariously, and purposefully, absurd. Embedded in these solutions, however, is solid scientific, engineering, and experimental understanding . . . [for] anyone who appreciates science-based, but Rube Goldberg esque, solutions to life s problems. Science Magazine

How To is a pure delight, a salty-sweet mixture of hard science and bonkers whimsy. BoingBoing

A brilliant provocation of a book: clamber in for a wild ride. Nature

A witty, educational examination of unusual approaches to common tasks . . . generously laced with dry humor . . . Munroe s comic stick-figure art is an added bonus. . . .  Apart from generating laughter, the book also manages to achieve his serious objective: to get his audience thinking. Publishers Weekly, starred review

An enjoyable treat for fans of logic puzzles, brain hacking, kaizen, mad science, and other forms of mental stimulation. Kirkus Reviews

Munroe (creator of the webcomic xkcd; What If?; Thing Explainer) creates another fun series of questions and answers that explore forces, properties, and natural phenomena through pop-culture scenarios . . . With illustrated formulas that humorously explain the science behind Munroe s conjectures, this