Part III of the Rock and Roll series: This one is for guitarists and vocalists. The subject: AMPLIFICATION.
Africa’s Namib Desert is one of the harshest and most unforgiving environments on Earth. Located off the aptly-named Skeleton Coast, it has the lowest annual rainfall of any place besides Antarctica. If you were shipwrecked there, you wouldn’t find drinkable water, but every morning you’d be treated to a tantalizing fog that rolls in from the ocean and quickly evaporates in the hot desert wind.
Because of the wind and the fog, it’s useless for native spiders to spin webs. So the Corolla Spider has a different strategy. It makes a burrow, and surrounds it with quartz pebbles.
The spider then attaches a strand of silk to each pebble, and waits in its lair. Quartz has a unique property: it’s piezoelectric. That means that it generates electricity when pressure is applied. Even the slightest brush of an ant’s antennae against one of the pebbles sends an amplified vibration down the silk strand to the spider, who then knows just where to pounce, without looking. The spider can even tell the difference between a potential victim, a larger predator, and the wind knocking on its mechanical trap.
We use quartz for the same property. It’s found in digital watches and electric cigarette lighters and, of course, piezoelectric pickups. The first phonographs used crystals pickups to convert mechanical vibrations into electricity, and today, piezo pickups are standard for amplifying acoustic electric guitars, and most microphones. My friend Ross explains the benefits of the piezo:
Piezoelectric pickups are more prevalent in acoustics, and have a cleaner sound, since they don’t operate via magnetic fields – i.e., they don’t pick up the hum of adjacent wires, like magnet driven pickups do.
Tony, another guitar-playing friend of mine, adds:
You’ll usually find the piezoelectric pickups under the saddle of an acoustic guitar, where the vibration of the string through the saddle activates the piezo effect. The crystals are embedded in a thin strip of magnetized metal. So a piezo pickup isn’t usually visible on a guitar, because it’s under the saddle.
So the spider uses the same technology we do to amplify sounds. It plays the guitar in reverse: the world makes a noise, and the quartz pickups send electricity through the strings. It puts its microphone to the world and listens.