This experiment is a trick that my Grandfather taught me when I was very young. He called it a "whistle stick", and making one brought back delightful memories from my childhood. This experiment requires the use of a sharp knife, so if you are young, you may need adult assistance. It is not difficult, but even adults should keep safety in mind.
To try this you will need:
- a popsicle stick (with the popsicle removed)
- a sharp knife with a short blade
- a pencil or pen
Making a Whistle Stick requires some whittling, the art of using a knife to shave thin slivers from a piece of wood. During my Grandfather's time, whittling was a common pass time, sometimes for carving interesting things, and sometimes just to give your hands something to do while you were thinking. While there are specialized knives for wood carving, most sharp pocket knives can be used for whittling. A dull knife will not work well, making it much harder to shape the wood, and much more likely that you will cut your finger instead.
The first thing to do is to eat the popsicle so you can get at the stick. Of course you can buy popsicle sticks from a craft or hobby store, but what is the fun in that?
Once all of the icy treat has been removed from the stick, we will use the pencil to mark the parts that we want to remove. Starting about an inch from one end, draw lines from each side that come inwards towards the end, as seen in the photograph.
Now comes the part where you have to be careful and patient. We are going to whittle away the wood that is outside those lines. Hold the piece of wood in your left hand (if you are right handed), and with the marked end pointing away from you. Holding the knife in your right hand, with the sharp edge pointing away from you as in the photo above. Always cut away from you, never towards your hand. You want to cut away very thin slivers of wood. Trying to cut too thick a slice will split the stick.
Once you get the stick close to the right shape, start cutting even smaller slivers, shaping and rounding the end. Don't worry if you make a mistake along the way. You can always eat another popsicle to get another stick.
Your Whistle Stick is now complete. To use it, press your finger and thumb together, as if you were going to snap your fingers. You can use either your first finger or your middle finger. Place the whittled end of the Whistle Stick in between finger and thumb. Then snap your finger. The Whistle Stick should fly away, making a strange, whistling sound. You may have to practice a few times, and the video should help with how to hold it and what to expect.
At the end of the video, I try the same thing with a tongue depressor which is quite a bit wider than the popsicle stick. Notice the difference in the sound.
Once you have played with the Whistle Stick a bit, then it is time to do some scientific thinking. Why does it make that sound? Why does the tongue depressor make a different sound? Listening to the two, you should be able to figure out what is happening. Give it some thought, and some experimentation (which may mean that you need more popsicle sticks), and we will look into that deeper next time.
Have a wonder-filled week!