Wind Power | Candle in the Wind

Can wind travel around an obstacle? Watch and find out!

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About ryan

I'm mom to two funny, silly, noisy boys (age 3 and 6) who are mostly best friends and occasionally worst enemies. I love doing all sorts of creative activities with my kids, but I'm especially enthusiastic about kid-friendly science experiments - the messier, the better!
  • exploring
  • moving-fine

What you need: a candle, a match, a tall square object like vase, and a tall round object like a drinking glass

What you do:

  1. Materials you need for this experimentSet the candle at a height so your mouth is at the same level as the flame. Use a sturdy pillar candle, or stick a birthday candle in a piece of playdough so it won’t fall over.
  2. Photo showing how to set up the materialsSet the square vase between you and the candle. With your mouth very close to the vase, blow hard. The vase blocks the wind, and the candle doesn’t go out.
  3. Photo showing how to set up with the round glassNow try the round glass. The candle should be a few inches behind the glass, and your mouth should be quite close to the glass.
  4. Photo showing how to blow out the candleBlow hard at the glass - the wind will travel around the glass and put out the candle!

Questions to explore:

  • How can the wind blow out the candle, when the glass is in the way?
  • What happens if you use a square object instead of a round one - does the candle go out?
  • Does the wind always blow in a straight line, or can it go around something?

Why it works (or Other Variations to try)

In the video, we saw wind go around the glass and put out the candle. Remember how wind is just air moving from one place to another? We can’t see air with our eyes, but with experiments like this one, we can see how it moves.  The glass is a smooth curve with no corners, so the air can travel around it, just like water flows around a rock in a stream. The vase, on the other hand, has a square side with a sharp corner. The air hits it and can’t slip around the corner to reach the candle. Try different objects and see which ones the wind can get around!