Saturday, June 8, 2013

TROPICAL STORM ANDREA IS GONE, TIME FOR A RAINBOW

We are lucky enough to have rainbows form in our back yard quite often.
The hurricane season is officially here on the east coast with an early start from Tropical Storm Andrea. Yesterday was definitely not a day to head outdoors. Today, however, is a different story. The clouds are thinning and the sun is slowly forcing its way through the heavy gray haze—the perfect recipe for a rainbow.

Today I am posting an easy way for your kids to make their own rainbow—no rain required. So, head outdoors, grab the hose, and have some wet summer fun.

HOW CAN YOU MAKE YOUR OWN RAINBOW?

Time to complete: 20-30 minutes
Ages: Anyone can enjoy this activity 

Materials:
Garden hose with an adjustable nozzle attached
Photographs of naturally occurring rainbows
Picture of a right triangle or angle
Open space outside
Sunshine (the sun should NOT be directly above you)
Instructions:

1. Show the children images of naturally occurring rainbows (single and double rainbows).
Ask: What colors do you see in the rainbows? How do you think these rainbows are created? Look closely at the double rainbows. How are they different?
2. Show children the picture of a right triangle.
3. Demonstration:
            a. Position yourself with the sun directly behind you so that you and your shadow form the legs of a right triangle, as shown.
            b. Position the hose approximately halfway between your shadow and you. The actual angle is 42 degrees for the primary rainbow and 50 degrees for the secondary rainbow. However, using the phrase halfway will be easier for the children to understand.
            c. Have a child turn the water on FULL blast. Arc the hose spray to create the rainbow. The rainbow should be formed close to the halfway point between the legs of the triangle.
Ask: What colors do you see in the rainbow? What color is at the top? At the bottom?
4. Have the children take turns creating their own rainbows. It may be possible to create a double rainbow in this manner, but the secondary rainbow will be faint.
 
Conclusion:
To create a rainbow you need a source of light and something that will refract and reflect the light. The light from the sun is refracted (bent) and reflected (bounced) inside the droplets of water from the hose. As each color of the rainbow has a different wavelength, the way they are refracted and reflected causes the sunlight to split into the different stripes of the rainbow.



RAINBOW fact: Double rainbows are actually mirrored rainbows. The primary rainbow is on the bottom with the spectrum colors beginning with the red stripe. The secondary rainbow begins with the violet stripe and is not as bright as the primary rainbow.
There are many ways to create a rainbow—using CDs, water, water and oil, and many more. Try your own hand at creating rainbows.

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