Anyone can blow out a candle. But can you make a candle go out with a sound? Challenge your family and friends to try and make a lit candle go out using only sounds. Then put out this cool Sound Wave Candle Snuffing Device and amaze your family with this super scientific way to make a candle go out.

Materials Needed:

• 2 liter plastic bottle
• Large plastic bag or plastic wrap
• Rubber band (large enough to go around the bottle)
• Scissors
• Small candle
• Matches

Do This:

• Cut the base off the plastic bottle. Be careful not to cut yourself on the sharp edge of the plastic bottle.
• Cut a piece of from the plastic bag or plastic wrap large enough to completely cover the opening of the bottle you just made with a little hanging over the edge.
• Stretch the piece of plastic tightly over the big end of the bottle. Secure it with the rubber band.
• Place the candle on a table and Light the candle. Make sure you have permission from an adult in the house to use matches and a lit candle!
• Hold the bottle with its neck about 2 inches away from the flame.
• Tap the piece of plastic sharply with your fingers. Did you hear the little drum sound? What happened to the candle flame?

Here’s what happened

Tapping on the plastic makes the little particles of air inside the bottle next to the plastic vibrate or shake back and forth. A sound wave is created. Each little vibrating particle of air touches other particles of air close to it to also vibrate. Very quickly the little particles of vibrating air move through the bottle and out into the air around the candle. Voila! The air around the flame is disturbed and the oxygen needed for the candle to burn is momentarily no longer available.

Further experiments

• Try to blow out the candle from different distances. What is the farthest away the Sound Wave Candle Snuffing Device can be from the candle and still work?
• Try to blow out the candle from different positions; above the candle, below the candle, at different angles. Does the Sound Wave Candle Snuffing Device work equally well in every position? What does that tell you about how sound waves move through air?

Adapted from The Usborne Big Book of Experiments