Rainbows are one of the most beautiful parts of nature’s huge variety of incredible spectacles. Why not recreate your own rainbow and perhaps in the process, discover more about how they work?
This experiment requires only household objects and can be done relatively quickly and easily – with some impressive effects.
To make your own rainbow spinner all you need is white paper or cardboard, colouring pencils or markers, a compass (parental supervision required for younger children), a pencil and a protractor for added accuracy.
First of all, cut a perfect circle from white paper or preferably cardboard using your protractor.
Then divide the circle in segments of about 51 degrees, each should be about the same size for the experiment to work!
Then colour each segment, staying in between the lines, all the colours of the rainbow: red, orange, yellow, green, blue, indigo (a lighter blue pencil should work as indigo is halfway between blue and violet, and violet is halfway between blue and purple) and then violet.
Push a pencil through the centre of the circle and blue tack it at the back so it doesn’t slip out.
Now you have your rainbow spinner which is a great way to show how rainbows develop, and what happens when all the colours are mixed together.
Rainbows are formed by white light from the sun being split into all its component colours by a process called refraction. This happens when a beam of light is spread out, in this case by water droplets. The rainbow spinner reverses the process by taking all the colours of the rainbow and merging them back into white.
We can surmise from the experiment that at the end of a rainy patch light is refracted by water droplets which in turn creates a rainbow, however there still isn’t proven scientific evidence that there’s a pot of gold at the end of one!
If you’re feeling a bit lazy, and don’t want to have to spin the spinner yourself, there are cheap fans available at some €2 shops that can be easily attached with blue tack to your rainbow spinner that will do all the spinning work required.
In the story of Noah’s Ark, the rainbow was a sign that God promises never to flood the earth again; now you know the science behind the creation of a rainbow friends and family can be impressed by this fun and easy experiment which shows that white light is more than it appears to be.