Look at all the pretty colors!
Refraction and rainbows.
"I wonder how that beautiful rainbow is made?”
“Simple –
refraction
(check out the online science dictionary definition) of light!”
Now you either know exactly what I mean or you have a blank stare on your face. It doesn't matter either way, you will still be discovering how science can be beautiful. This phenomenon of light is something that Sir Isaac Newton first used to make a rainbow, and now you are going to do the same.
This project has two experiments. In the first experiment you will discover something about light. In the second you will be using your newly gained knowledge to make a rainbow.
Let's do science...
The project – step by step
The Question
How are rainbows made?
The Hypothesis
White light
(check out the online science dictionary definition)is made up of different colors. Refraction will split white light into its different colors to make a rainbow.
The Experiments
Colors of the rainbow
(This experiment is aimed at grade 1 kids. Don't be deceived that because something is simple it can't be used. I mean our favorite friend Sir Newton came up with the idea of gravity when an apple fell on his head!)
Refraction of light – how to make a rainbow
Why these experiments?
The
first experiment
(you can choose one of the three experiments from here) is simply to show that light is made up of many colors. The rainbow that you get from this experiment may not look exactly like the rainbow everyone knows.
The
second experiment
is a bit more complicated and needs special equipment. With refraction and special conditions, the colors of the rainbow, in the correct order will form before your eyes! Just think, you will be doing the same experiment Sir Isaac Newton did. How cool is that!
Remember to keep a record of your discoveries in your
log book.
The Conclusion
Light, which is called
white light
(this definition is in the online science dictionary), can be split into the colors that make it up and this is the rainbow that we see. This happens because of refraction.
“Beef up your project” facts
There are seven colors in a rainbow: red, orange, yellow, green, blue, indigo, violet.
Question: Why does refraction of white light end up in different colors?
Let's check out what we know already:
Light slows down and bends when moving to a different medium (refraction).
Now some more interesting facts:
Light moves like a wave.
Picture yourself at the beach. When you are in the surf, the waves sometimes hit you quickly one after the other, and other times you have to wait what seems like an age before the next wave comes along. The space between waves is the wavelength, the quicker they hit you, the shorter the wavelength.
Each color in white light has a different wavelength.
Aha! Starting to make sense? If each color has a different wavelength, the ones with a shorter wavelength will bend more (at more of an angle) as they slow down and the ones with a longer wavelength will bend at less of an angle. So red, which bends the least has the longest wavelength and violet with the shortest wavelength will bend the most.
Look it up
Here is one for you to stretch the gray matter a bit ... part of science is research – see if you can do some research to find the answer to the following:
Why do normal rainbows always form in an arch?
More...
This is for all those arty people out there. How about trying this out:
Create a rainbow on a wall, using a prism, place some paper where the rainbow falls and use paint to make your own artistic rainbow painting.
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