I find it interesting what my children retain from watching television. My kids watch PBS and borrowed videos from the library. On occasion, we'll get them a movie from Redbox or Netflix. Today, after watching something (am I terrible to not have any idea what show it was?), I think it was a segment in between shows, Eli approached me with a list of items he needed. "Mom, I need some white paper, a glass with some water in it and a flashlight." Okay, MacGyver. What in the world are you doing? "I saw it on TV, mom. I want to make a rainbow." Okay, let's do it.
I have an inkling of what he's talking about, but I was still reeling from his interest in trying out this experiment.
I got a few sheets of white printer paper. I grabbed one of the newly excavated glass jars we found in the back yard today and filled it with water. Then, I found the flashlight. All set. It took a minute to figure out how to find the rainbow. At first, I had the sheets all laid out. There was nothing. Then I put a sheet of paper as a backdrop and it seemed to have an effect. We had to shine the flashlight from the top of the water level and aim down in order to achieve a rainbow. How very cool.
Now, why does it do this? I found my answer in an issue of Turtle Magazine. I tried to find it on PBS, but there were entirely too many listings for me to flip through. The folks at Turtle say, "When you shine a flashlight beam through the glass of water, the light is refracted, or bent. when white light is refracted it creates a color spectrum - the colors you see in the rainbow. So white light is really a mixture of many colors! In 1666, a scientist names Issac Newton made this discovery by using a piece of glass called a prism to split a beam of sunlight, creating a color spectrum. The same thing happens when you see a rainbow in the sky. Raindrops act like tiny prisms to split the sunlight into different colors."