Keep a Candle Burning Underwater!

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Updated on Jun 25, 2010

Magic tricks can't hold a candle to this scientific triumph! Watch your child's astonishment as he sees that he can make a candle burn below water, and create a very bizarre candle souvenir. With just the open flame above the water's surface, this process will transform the candle to a hollow tube of wax. The water surrounding the candle is the secret to this "trick"! It keeps the exterior of the candle at a cool temperature, so the area touching the water never melts!

What You Need:

  • Taper candle
  • Large bowl
  • Duct tape
  • Cigarette lighter or candle
  • Cold water
  • Scissors

What You Do:

  1. Have your child cut off four 4” lengths of duct tape.
  2. Invite him to fasten the candle to the bottom of the bowl with duct tape.
  3. Help him fill the bowl with water just to the top of the candle. Be careful not to submerge the wick!
  4. Light the candle for your child. Instruct him to be careful of the open flame!
  5. Encourage your child to observe what happens. The candle should burn all the way to the bottom of the bowl, leaving a thin tube of wax.

What Happened?

If you had lit and burned the candle in a waterless bowl, it would have burned normally and eventually consumed the whole candle. This is caused by the action of both heat flow and a high temperature. Get your child thinking: Why did the candle burn differently when he added water to the bowl? It only seems like magic that the candle burned while it was underwater!

Water has the amazing quality of absorbing heat energy, and because you used cold water, even more heat energy was absorbed. Once the candle's heat energy dissipated into the water, the heat had much less impact on the outer surface of the candle, resulting in the candle's strange transformation.