Halloween is all about things that glow in the dark, things that are slimy, things that bubble and boil, but Halloween isn’t Halloween without spooky, eerie sounds.
If you are planning a Halloween party at school or in your home, here are some ideas to set the sound stage.
**Caution! This experiment uses small pieces, so be very careful if you are doing this activity with young children. Adults should blow up the balloons and tie them off before giving to children.
This is an easy experiment you can do with a balloon and a hex nut. If you are doing this with a large group, make sure to get enough supplies so everyone can go home with a screaming balloon.
Squeeze the hex nut through the mouth of the balloon. Make sure that the hex nut goes all the way into the balloon so that there is no danger of it being sucked out while blowing up the balloon. Tilt the balloon down to keep the hex nut inside. Blow up the balloon, but be careful not to over inflate the balloon as it will easily burst. Tie off the balloon and you’re ready to go.
Grip the balloon at the stem end as you would a bowling ball. The neck of the balloon will be in your palm and your fingers and thumb will extend down the sides of the balloon. While holding the balloon, palm down, swirl it in a circular motion. The hex nut may bounce around at first, but it will soon begin to roll around the inside of the balloon. What is that sound? Could the balloon be screaming? Once the hex nut begins to spin, use your other hand to stabilize the balloon. Your hex nut should continue to spin for 10 seconds or more.
For this experiment, you will need a large plastic cup, a piece of string (24”) and water.
Start by poking a hole in the bottom of the cup just large enough to thread the piece of string. Thread the string through the hole and tie a knot or two at the end of the string to hold the string in place. Wet the string. Holding the cup in one hand, pinch the string between your thumb and forefinger. Squeeze tightly on the string as you slide your thumb and forefinger down the string. With practice, and a little patience, the string will “stick and slide” between your fingers causing a “screaming” sound. Oh, you’ll know when you’ve got it down to a science!
Whirly Sound Hose or Singing Tube
At first glance, it looks like your ordinary plastic tube. Hold one end of the tube and twirl the other end in a circle over your head. It’s music to your ears! The “Singing Tube” is a popular and inexpensive item in toy stores. There is really nothing to it – a corrugated plastic tube measuring about 3 feet long and 2 inches in diameter. You can also look at the hardware store for different sizes of corrugated plastic tubes.
Spin the tube faster and notice how the pitch of the note goes up. Fast twirling creates high pitch notes and slower twirling creates lower notes. Amazing!
The Bag “Whirly”
Attach a plastic bag, such as a garbage bag or shopping bag to the end of your Sound Hose with tape or a rubber band. With your mouth a few millimeters from the Sound Hose, blow into the open end. The bag will inflate with just a few big breaths. Once the bag is inflated, twirl your Sound Hose. As the “music” plays from the hose, watch the bag deflate!
Not all plastic tubes sing. The tube must be corrugated on the inside. Why? The aerodynamics researchers in Japan put a whirly in a wind tunnel and used very tiny hot wire anemometers to measure the airflow near the corrugations. As the air flows first over one ridge then over a second it tumbles into a vortex. The faster the air flows through the tube, the higher the frequency of the sound produced by the vortex. When the frequency of the vortex matches one of the natural resonant frequencies of the tube it is amplified.
Guest blogger Susan Wells is the mom to two girls. She enjoys enriching her daughter’s education by finding the learning in everything. They especially enjoy science activities. She works as a blogger and social media strategist for Steve Spangler Science, a Colorado company dedicated to helping teachers and parents get children excited about science.