" Hopper pressed her engineers to streamline their code. (In wartime, a fraction of a second can separate life from death.) During lectures, she would hold up a bundle of wire cut to the length that electricity traveled in a microsecond, or 1 one-millionth of a second. It was 984 feet long. She said, “I sometimes think we ought to hang one [of these bundles] over every programmer’s desk, or around their neck, so they know what they’re throwing away when they throw away microseconds. "

― Chip Heath , Making Numbers Count: The Art and Science of Communicating Numbers