Saturday Science: The Gobblephone
It’s Thanksgiving season, and that means a few things: raking leaves, excellent deals at Best Buy, and TURKEY! If you are not vegetarian or vegan, you likely enjoy some delicious turkey at Thanksgiving dinner. I know I do. And even if you’re not a fan of eating turkey, it’s likely you’ll have some turkey decorations around the dinner table. Maybe you’ll even trace your hand and make one of those turkeys where your thumb is the head and your fingers are the tail. That’s great, as turkey decorations go, but that sort of thing only manages to involve a single one of your senses (unless you, like, try to eat your drawing, you weirdo). Today we’ll put together a festive Thanksgiving instrument that has two great features: it makes a really cool turkey squawk noise, thus engaging your sense of hearing in your Thanksgiving celebration, and it’ll really annoy the pants off your parents.
- A plastic drinking cup (like a Red Solo Cup; listening to that awful song is optional)
- Yarn or cotton string
- A paperclip
- Some paper towel
- A nail or thumbtack
- An adult
- Tape (optional)
- Cut a piece of your yarn/string somewhere around 20 inches long.
- Have your adult make a hole right in the center of the cup’s bottom with your nail/thumbtack. Make sure the hole is big enough for your yarn/string to go through.
- Tie one end of your yarn/string to your paperclip (maybe tape it for extra support).
- Put your yarn/string through the bottom of the cup and pull it through so that the paperclip is on the outside of the cup and the string is running through the inside and out the top.
- Snag a piece of paper towel. Fold it down so it’s 5-6 inches long and a few inches across.
- Wet your paper towel. Get it damp, but not quite sopping wet.
- Commence parental annoyance: hold the cup in one hand and your damp paper towel in the other. Fold the paper towel so you can pinch it on both sides of the string. Now jerk the string down. Just a short, hard pull. Hear that? That wonderful, joyful turkey call? Keep pulling down on the string to keep hearing it!
- Run away from your parents as they try to steal your Gobblephone and throw it away.
The Gobblephone may be a silly instrument, but it really is an honest-to-goodness string instrument. It’s a simple one, but it works on the exact same principles as a guitar or a violin. Gobblephone, banjo, heck, even a piano, all work by making strings vibrate. Vibrating strings create sound.
See, sound is really just a certain kind of vibration. It can move through any kind of matter, but typically, for us humans, it’s moving through air. In the case of your Gobblephone, the string vibrates, which makes the air around it vibrate, and those air vibrations travel through the air to your ears. The air vibrations vibrate your eardrum, which moves the 3 tiny bones in your ears, the vibrations move to your cochlea, where they are translated into neuronal signals, or signals that can travel through nerves, those signals move up your auditory nerve to your brain, and you think “Oh, no, mom said my whole name. What did I do this time?” Or whatever.
This sort of thing happens any time you pluck a string. You’ve probably played around with rubber bands to hear the different twangs they make as your stretch them more or less. But try it with some yarn/string outside the Gobblephone. Not too loud, is it? That’s where the cups come in, and why your Gobblephone really does have something cool in common with a guitar: it has a sounding board and a resonating chamber. See, normally the vibrations from a string like that are weak, which means a quiet noise. When you add the cup, your sounding board/resonance chamber, it does two thing. First, since it’s touching the string, it vibrates with the string, which amplifies the string’s vibrations. Second, all of the vibrations bounce around inside the cup for a while before coming out, which means that later vibrations essentially get added to earlier ones, and the whole sound is louder when it comes out.
Experiment with your design: try different string materials, or different string lengths, or different size/materials of cup. Anything you change will likely change the specifics of the Gobblephone. Figure out which one you like best (and/or which one your parents like worst) and go to town. Happy Thanksgiving!