Touch-N-Glow Ball

The Energy Ball may look like a simple ping-pong ball with two pieces of metal, but when both pieces of metal are touched simultaneously, the ball lights up and makes noise.

Experiments

1. Touch one metal contact. What happens?
2. Touch both metal contacts at the same time with the same hand. What happens? What happens if you use two hands? A hand and a toe?
3. Touch one metal contact. Have a partner touch the other. What happens?
4. Touch one metal contact. Have a partner touch the other with one hand, and have him/her touch your hand with the other. Does the ball light up?
5. Touch one metal contact. Have a partner touch the other with one hand. With the free hand, have each person hold a piece of metal. Does the ball light up?
6. Touch one metal contact. Have a partner touch the other with one hand. With the free hand, have each person hold a piece of plastic. Does the ball light up?
7. Have two students each touch one of the metal contacts. Have the rest of the class hold hands (or make some kind of contact) with each person touching the metal contact in the circle. Does the ball light up? How big can you make the circle?
8. Take two energy balls and line them up so that a metal contact on ball A is touching a metal contact on ball B. Touch each of the other metal contacts (one from each ball). Does it light up?
9. Have two students touch one of the metal contacts. Have each student put a finger of the other hand in a glass of water without their fingers touching. Does it light up?

How does it work?

You should have observed that the ball lights up and makes noise when it is touched by the same person or by two people touching each other. The Energy Ball contains two exposed contacts and a small amount of electricity. The electricity cannot be used to turn on the light in the Energy Ball unless the electricity can move freely from one metal contact to the other. By touching each contact, you are completing an electrical circuit in the Energy Ball. If electricity can move from one piece of metal to the other, the circuit is closed and the ball will come to life.

You may know that tap water is an excellent conductor of electricity. (That’s why you shouldn’t go swimming when there is lightning—the electricity from the lightning can travel through the water and shock you.) The human body is about 65% water with salt dissolved in it, so the electricity can travel through a human from one contact to the other. When we perspire a layer of salt water is on the outer layer of skin. Most metals conduct electricity, which is why two partners holding a piece of metal can make the ball light up. Plastic, on the other hand, does not conduct electricity. Anything that does not conduct electricity is called an insulator. When an insulator blocks the flow of electricity from one metal contact to the other, the ball does not light up.

Circuits

The word “circuits” sounds like another word, “circle.” This is not a coincidence. A circuit is a closed circle through which electricity flows. If there is a break in the circle or circuit, the electricity cannot flow through it. When you flip a light switch to the “on” position, the electrical circuit is closed, so the light can turn on. Turning the light switch to the “off” position creates a break in the circuit, turning off the light.

Fun Facts

• Light bulbs work in much the same way as an Energy Ball. The filament in a light bulb (the small wire that emits light in the middle of the bulb) provides the connection to close the circuit. A dead light bulb stops emitting light because the filament breaks and the electricity cannot travel through it.
• Insulators like certain kinds of rubber are used to cover electrical cords so that they are safe to touch. Be careful not to touch an electric cord that does not have an insulator.