... How Things Work Encyclopedia DK PUBLISHING LONDON, NEW YORK, MELBOURNE, MUNICH, and DELHI Senior Editors ... sound Light and sound Now you see it Light and bubbles Mirror,rorriM Lenses How light works Fireworks Measuring sound How ears hear Electric guitar 122–125 Glossary 126–127 Index 128 Picture credits ... change the way people live their lives—they make things safer, easier, faster, or cheaper Knowing your stuff Technology is the science of how things work The inventors of these shoes knew that a...