Not your usual experiment, this is a book: “The League of Scientists” is a young adult fiction book by Andy Kaiser (the creator of Digital Bits Science Lab).

Equipment needed:

The League of Scientists is available here: http://www.LeagueOfScientists.com

The Digital Bits Science Lab Experiment:

The League of Scientists is a group of smart kids who love science. They use their knowledge and critical thinking skills to solve seemingly-supernatural mysteries.

One of the components of the book is the mystery aspect, and not just the “main” mystery. In most chapters, there is a puzzle. The solution to the puzzle involves the application of science or critical thinking. The book is intended to give science education (and scientific applications – something you don’t always get from such fiction) while still giving kids a good story and characters.

One of the classic fun things to do with a balloon is to “squeak” it. This easy game is the result of some interesting science – air pressure and sound at the molecular level. This is also very similar to the way we use our vocal cords to speak.

Equipment needed:

Balloons

The Digital Bits Science Lab Experiment:

Blow up a balloon. Hold the mouth of the balloon in both hands. Stretch the mouth, pinching your fingers on the balloon while pulling them apart, as in the picture below.

As the air flows out of the balloon, you’ll hear a high-pitched, loud squeaking noise. You can adjust the tension on the balloon mouth, and the pitch and volume of the squeaking will change.

What’s happening here? Why does a balloon squeak when you stretch the mouth?

Stretching the mouth of the balloon makes a very tiny space for the air to flow out of the balloon. The air pressure of the balloon itself forces the air out the mouth, but because of the stretching, that space is limited. The airflow causes the balloon mouth (the stretched part) to vibrate. The vibration makes the noise.

Put your hand on your upper neck – right under your jaw – and hum. You’ll be able to feel a vibration, similar to the vibration at the mouth of the balloon. This is air being forced over your tightly-stretched vocal cords. Remember how tightening or loosening the balloon mouth changed the sound of the squeaking? Hum in a high pitch and feel your neck. Hum in a low pitch, and the vibration will change.

You talk using a similar method to the way the balloon squeaks. But the balloon experiment is a simple demonstration, capable of just a few annoying noises. Your body is a highly-developed machine. You can make noises a lot more impressive than any balloon.

This experiment shows the concept of energy transfer, how kinetic energy can be transferred from one object to another. While a “drum” and “drum sticks” are required below, this experiment can actually be done with any drum-like and drumstick-like objects. A big inverted tupperware container and two big wooden spoons, for example, will work fine.

Equipment needed:

A drum

Two drumsticks

The Digital Bits Science Lab Experiment:

Use the drumsticks and whack the drum a few times to get a feel for the sound and amount of force needed to get a good drum noise.

Next take both drumsticks, and hit them together. Listen to what kind of sound it makes when one drumstick hits the other one.

Then hold one drumstick in each hand. Place one drumstick on the surface of the drum. Hold the other stick above the drum:

Keeping the end of the lower drumstick on the drum surface, bring the upper drumstick down and strike the center of the lower drumstick.

What happens? It sounds like you’ve just hit the drum, even though you’ve only hit one drumstick with another!

This experiment is an example of the transfer of kineitc energy. When the upper drumstick hits the lower drumstick, the energy from that hit moves from one drumstick to the other. This happens because the sticks themselves are touching. (Kinetic energy moves easily through small solid objects like the drumsticks.) But the lower stick is also touching the drum. So when the upper stick hits the bottom stick, the energy keeps moving: It flows from one drumstick into the next, then from the second drumstick into the drum.

Equipment needed:

Plastic drinking straws

Scissors

The Digital Bits Science Lab Experiment:

What we’re trying to do is to create a simple musical instrument out of a plastic straw. It’s pretty easy. First, cut the top of a straw into what looks like a triangle. (It may help if you squish the straw end first before cutting it – this ensures the cut is the same for the top and bottom of the straw.) When you’re done, one end of your straw should look like this:

Next, blow into the straw. You’ll need to blow pretty hard, and your lips will seal firmly around the straw right at the point where you first made the cut. You may have to move the straw back and forth a bit until you find the right place. The parts of the straw should be flat, and parallel with your tongue – don’t rotate the straw, or the noisemaking will get very difficult or impossible. When you’ve got the right technique, you’ll be rewarded with a buzzing noise coming from the end of the straw.

This is it – we’re making sound! This is the same noise-making concept as reeded musical instruments, like the clarinet and oboe: blowing air over a reed (in this case, our cut straw end) makes that reed vibrate. When it vibrates at the right speed, it makes a noise. A similar technique also allows you to talk. Your vocal cords are just like this straw: you blow air over your vocal cords, and your vocal cords vibrate, and this makes noise come out of your mouth. The difference is that in speaking, your mouth, tongue and many other factors work together. They change various parts of how the air flows and how fast your vocal cords vibrate. This control allows us to form words, sing, and make many other interesting noises.

You can use this concept with our “straw clarinet”, too: cut the straw at the other end (the end you don’t blow into). Shorten it. Make more “straw clarinets”, and cut them to several different lengths. When you blow into these, you’ll find the noise is different from each one. Finally, if you’re really talented, try blowing while changing the tightness of your lips, or varying the amount of air you’re blowing – you’ll find that the noise will change as well.