Preface
For the past several years, I've been learning to play the cello. As any adult who has ever tried to learn a musical instrument—especially a fretless stringed instrument—can tell you, it's painfully hard. You feel like you don't really know your body at all: your muscles get sore in odd places, you develop strange calluses on your fingers, and you perform stretches with your hands you never thought possible. It requires almost all of your concentration simply to coax the instrument into making a pleasing sound, which is very different from actually making music.
But, ah, when you do begin to make music, it is a thing of joy. When you are able to get a sweet sound with emotional resonance from an inanimate object using only your body, it is an amazing feeling. Gestures create meaning.
That's what this book is about.
Technological, social, and market forces have converged to create a fertile new ground for designers and engineers to plow. The price of processing speed has dropped and sensors are readily available. Touchscreens on our mobile devices, ATMs, and airline check-in kiosks have taught us to expect to be able to manipulate things on-screen with our hands. Games have shown us we can make gestures in space to control objects on-screen. Public restrooms are, believe it or not, test laboratories for interactive gestures: placing your hands under a faucet to turn it on, waving your hands to get a paper towel, stepping into a room to turn on the lights.
All of these things ...