Introduction: The light of the Sun is very strong. If you use a magnifying glass to concentrate and direct the beam of light you can start a fire. Using the same heat we can do "solar writing".

Since this experiment involves fire you need an adult to help you with this experiment. Do not attempt to do this alone.

After discussing the energy of the Sun and the uses of the Sun for solar power try this experiment.

Materials:

• magnifying glass
• piece of paper
• small piece of wood
• sunny day

Note: pick a place where there is no danger of fire spreading - a patch or bare ground on a table top.

Procedure:

1. Set the piece of paper on the ground or table.
2. Hold the magnifying glass over the paper until you see the Sun's light on the paper.
3. Move the magnifying glass back and forth, closer and farther away, until you make the smallest possible dot of light on the paper.
4. Wait a few moments.
5. Do the same thing with wood. If you are careful, you can burn letters in the wood by moving the dot of light slowly and carefully.

Results:

First the paper will start to smoke, then turn brown. A hole will burn through the paper. Some kinds of paper will catch fire.

The intense energy from the Sun has been harnessed by the concentration of light through the magnifying glass. This has generated enough heat to start the burning.

     

              
             

©Copyright 1998 Elizabeth Beckett, Holly Bernitt, and Vishwa Chandra.