How to Make Water Rise

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It's not in defiance of the law of gravity to make water rise, but you'll need a few tools and a little help from science. Here's how.
 
 

 Things You'll Need

  • A plate or tray, such as a pie plate or meat tray
  • A match
  • A candle
  • A lump of clay if necessary to hold the candle upright
  • Water
  • Tray of water, candle, glass.
    Tray of water, candle, glass.
    A glass or flask

 

Steps

  1. Gather all your supplies, listed below.
     

  2. A shallow dish of water.
    A shallow dish of water.

     

    Place about an inch (2.5 cm) of water into a tray or plate. Try a pie plate, a dish pan, or a clean foam tray such as the kind used to sell meats.
  3. Place a candle in the middle.
    .
    Place a short candle in the middle of the tray. If it doesn't stand up by itself, use a small lump of clay to secure it to the bottom.

     

  4. Light the candle.
    .
    Light the candle.

     

  5. Place the glass or flask over the candle.
    e.
    Carefully place the inverted glass or flask over the candle, setting the rim into the water.

     

  6. The water will rise inside the glass.
     
    Watch as the water rises and the candle goes out.
     

Why this works

Notice carefully as the water rises in the glass. Repeat the experiment a few times, if you need to. While the candle goes out because it consumes oxygen, that's not why the water rises. The water rises after the candle goes out.

  • As you lower the glass over the candle, the flame heats the air inside the glass.
  • The glass contacts the surface of the water, trapping a volume of warm air.
  • The candle goes out and this warm air cools rapidly.
  • Air that cools rapidly under a constant pressure does so according to Charles's law[1], a specific version of the ideal gas law that holds the quantity of gas and the pressure constant. Charles's law holds that the ratio of Volume to Temperature is constant.
  • Since the temperature decreases, the volume must also decrease.
  • Additionally, some water vapour may condense on the sides of the glass and back into the liquid water. This also reduces the total volume of gas inside the glass.

 Tips

  • Recall that atmospheric pressure acts on the water outside the glass.
  • Try predicting the temperature difference based on the volume difference. Measure the distance the water rises and estimate the volume change based on the diameter of the glass (it helps if the glass has fairly straight, cylindrical sides). Remember that Charles's law operates on absolute temperature, so you'll need to use a Kelvin temperature scale.