Introduction: The Sun is the beginning source of rainbows. Because of the light of the Sun and the properties of refraction, reflection, and absorption we have rainbows.

Using thinking and observation skills this experiment will help the student learn what a rainbow is, the colors of a rainbow, how to make a rainbow, and what causes a rainbow.

Materials:

• Bright sunshine
• Hand mirror - any size
• Tin foil pie plate
• Water - to fill the pie plate
• One piece of 8-1/2" X 11" unlined construction or regular paper.

Procedure:

1. Fill pie plate with water
2. Put pie plate on a table in a very bright, sunny room.
3. Place the mirror in the pan so that the mirror is underwater and leaning against the side of the pan.
4. Place the pan so that the Sun is shining directly on the mirror.
5. Slowly move the mirror in different directions, until you see a row of colors on the wall or the ceiling.
6. Take the materials outside.
7. Again set up the pie plate on a table or other flat area in full sunshine.
8. Refill the pie plate and reposition the mirror so that it is leaning against the side.
9. Take the piece of paper and put it in front of the pie plate and mirror and catch the colors on the paper.
10. Try different angles of the pie plate and mirror to get the Sun shining on the paper correctly.
11. Count the colors that you can see.

Results:

As the light strikes a solid object, it is absorbed or reflected. When it strikes a transparent object, such as a pan of water, the light rays are bent or refracted. The different colors are bent at different angles, and when the light emerges, the colors will break apart into a rainbow.

As the sunlight hits the water in the pie plate it is slowed down. This causes the colors to separate. When the light is reflected back from the mirror back through the water and into the air the colors are separated further. This is why you see the colors so clearly.

This is how a rainbow is formed. Sunlight appears white to us, but it is really made up of red, orange, yellow, green, blue, indigo, and violet. All these colors together are called the colors of the spectrum.

     

              
             

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