Light from a Lifesaver
Did you know that you can generate electricity and flashes of light with a piece of wintergreen candy?
To try this, you will need:
- a FRESH package of Wintergreen Lifesavers. It MUST be fresh and it MUST be Wintergreen flavor.
- a pair of pliers
- a totally dark place to try your experiment. This could be a closet, or a room with no windows.
Spread the newspaper on the floor. This will catch the bits of lifesaver when you break them, and save you some clean up time later. Turn out the lights and get the room as dark as you can. You may want to do this at night, because even a little light will keep you from seeing what we are looking for. Once it is nice and dark, wait for a few minutes, to let your eyes adjust to the darkness. As your eyes start to adjust, you may see light coming in under a door. If so, use a rolled up towel to block the light.
Once your eyes have adjusted, place a lifesaver between the ends of the pliers and then crush the lifesaver with one quick squeeze. You should see a blue flash. If not, try again. With a little experimentation, you will find out just how hard to squeeze to get the brightest flash of light.
What is happening? The lifesaver contains sugar crystals, and sugar is piezoelectric. Piezoelectricity is electricity produced by pressure. When you put pressure on certain kinds of crystals, they become charged with electricity. The crystal will have a positive charge at one end and a negative charge at the other. If the pressure is strong enough, the crystal can produce a spark. When you squeeze the lifesaver, the crystals of sugar in the candy produce tiny sparks of piezoelectricity. The problem is that these sparks are too small and dim to see. That is why we need to use wintergreen flavored candy. The flavoring used in wintergreen candy is methyl salicylate. This chemical will glow blue when it is exposed to ultraviolet light. Although the tiny sparks are too dim to see, they produce enough ultraviolet light to make the methyl salicylate glow, giving you the flash of light that you see.
Piezoelectricity is used for many different things. It is used to produce a spark to ignite the gas in some butane lighters and propane grills. It is also used in some microphones. When sound waves hit the microphone, they squeeze the crystal inside. Each wave causes a tiny squeeze, which produces a tiny burst of electricity. This changes the sound waves into a series of electric pulses, which a speaker can change back into sound.