Why do we have Rainbows??
by Katie, age 10, 5th Class.
Rainbows are very common. The colours are: red,orange,yellow,green,blue,indigo and violet. A rainbow isn’t really there so you cant go over it or find the end of it. Some cultures have myths about them because it is unattainable. In Navajo and Norse mythology it’s a bridge only Gods can take between heaven and earth. For Christians and Buddhists the rainbow symbolises peace and forgiveness. In Ireland it was thought that there was a pot of gold at the end of the rainbow, guarded by leprechauns.
A rainbow exists because of water,sunlight and a little bit of physics.
Sunlight looks white but it’s actually not. Isaac Newton discovered that white light is actually made up of several different colours.
On a rainy or misty day the sky is full of tiny droplets of water. As rain drops become spheres each one can become part of a rainbow. As the light enters one side of the drop it bends slightly (thanks to a process called refraction). Different wavelenghts of light bend at different angles which causes the white light to separate. The bent sunlight reflects off the back of the raindrop and bends again on the way out. The angle between the light that goes in and the light that goes out measures 42 degrees.
Rainbows are actually circle shaped. They look bow-shaped because the horizon gets in the way of seeing the rest of the rainbow. However it is possible to see a circular rainbow if you’re sufficiently high and the sun is in the right spot behind you. Occasionally, pilots have reported seeing complete, circular rainbows at very high altitudes.
Our Light Experiments
No.1 Making Colours Disappear
Can we make the spectrum colours disappear into white light
What I needed
I needed a circle with the colours of the spectrum on it and a motor
What I thought would happen
I thought that the motor would spin and that the colours would disappear because it was spinning so fast.
What I did
When I pressed the on-button the circle began to move.
In the beginning the colours were still there until it got really fast.
When it was really fast we could only see white.
When colours move quickly they make one single colour=white.
No 2. Splitting Light
Can we split light into the seven colours of the rainbow’
What I needed
The first time we did this experiment we only had a torch as a light source.
What I thought would happen
I thought that when the light shone on the prism that the prism would split the light into the 7 colours of the rainbow.
What I did
The first time (with the torch) I shone the light toward the prism
The second time we went outside and held the prism near the wall and the sunlight shone directly at it.
We also tried a magnifying glass in direct sunlight.
With the torch we could not see any spectrum.
The magnifying glass also refracted the light. This time it gave us a circle of spectrum colours
That white light is made up of not just one colour but 7 colours of the spectrum.
Poems about Rainbows
My heart leaps up when I behold
A rainbow in the sky:
So was it when my life began;
So is it now I am a man;
So be it when I shall grow old,
Or let me die!
The Child is father of the Man;
And I could wish my days to be
Bound each to each by natural piety.
The rainbow Story
Once upon a time the colours of the world started to quarrel: all claimed that they were the best, the most important, the most useful, the favorite.
Green said: “Clearly I am the most important. I am the sign of life and of hope. I was chosen for grass, leaves, trees–without me, all animals would die. Look out over the countryside and you will see that I am in the majority.”
Blue interrupted: “You only think about the Earth, but consider the sky and sea. It is the water that is the basis of life and drawn up by the clouds from the deep sea. The sky gives space and peace and serenity. Without my peace, you would all be nothing.”
Yellow chuckled. “You are all so serious. I bring laughter, gaiety, and warmth to the world. The sun is yellow, the moon is yellow, the stars are yellow. Ever time you look at a sunflower, the whole world starts to smile. Without me, there would be no fun.”
Orange started next to blow her temper. “I am the colour of health and strength. I may be scarce but I am precious for I serve the needs of human life. I carry the most important vitamins. Think of carrots, pumpkins, oranges, mangos, and pawpaws. I don’t hang around all the time, but when I fill the sky at sunrise or sunset, my beauty is so striking that no one gives another thought to any of you.”
Red could stand it no longer. He shouted out: “I am the ruler of all of you. I am blood! Life’s blood. I am the colour of danger and of bravery. I am willing to fight for a cause. I bring fire to the blood! I am the colour of passion and of love, the red rose, the poppy and the poinsettia. Without me, the earth would be as empty as the moon!”
Purple rose up to his full height. He was very tall and spoke with great pomp: “I am the colour of royalty and power. Kings, chiefs, and bishops have always chosen me for I am a sign of authority and wisdom. People do not question me. They obey.”
Finally, Indigo spoke, much more quietly than all the others but with just as much determination: “think of me. I am the colour of silence. You hardly notice me, but without me, you all become superficial. I represent thought and reflection, twilight and deep water. You need me for balance and contrast, for prayer and inner peace.”
And so all the colours went on boasting and quarreling, each convinced of their own superiority. Soon, their quarreling became louder and louder. Suddenly there was a startling flash of bright lightening! Thunder rolled and boomed! Rain started to pour down relentlessly. The colours crouched down in fear drawing close to one another for comfort.
In the midst of the clamor, Rain began to speak: “You foolish colours, fighting amongst yourselves, each trying to dominate the rest. Don’t you know you were each made for a special purpose, unique and different? Join hands with one another and come to me.”
Doing as they were told, the colours united and joined hands. The rain continued: “From now on, when it rains, each of you will stretch across the sky in a great bow of colours as a reminder that you can all live in peace. The rainbow is a sign of hope for tomorrow.”
And so, whenever a good rain washes the world and a rainbow appears in the sky, let us remember to appreciate one another.
Songs about rainbows
The rainbow has inspired art and music over the centuries.