Everyone will agree that a rainbow is one of nature’s most splendid masterpieces. A simple phenomenon of bending of light as it passes through water droplets can create such an amazing spectrum of colours: Rainbow! Light is refracted as it enters the raindrop, then reflected inside the drop and again refracted as it goes out of the drop. How can we view rainbow ?? To have a view, your back must be to the sun as you look at an approximately 40-degree angle above the ground into a region of the atmosphere with suspended droplets of water or even a light mist. Each droplet of water acts as a tiny prism that both disperses the light and reflects it to your eye. As you sight into the sky, wavelengths of light associated with a specific colour arrive at your eye from the collection of droplets.
“Rainbow” comes from the Latin word “arcus pluvius”, meaning “rainy arch.” Ever wondered how rainbow got its name?? Rainbow got its name from its shape. A rainbow’s arc looks similar to a bow for shooting arrows. People also noticed that this colourful arc would only form when it was raining so they called it a rainbow. There is another interesting thing about a rainbow is that no two people can see the same rainbow… Its because a person standing next to you is standing in a slightly different spot and sees the rainbow in a slightly different place. The rainbow may look the same but there a little different because the person next to you sees different raindrops. It’s actually an optical illusion appearing because of the angle to the water droplets with the light.
Most people have never noticed that the sun is always behind you when you face a rainbow and that the centre of the circular arc of the rainbow is in the direction opposite to that of the sun. The rain, of course, is in the direction of the rainbow.
The truth is, there is no set number of colours in a rainbow! Each hue blends into the next without a hard boundary, leaving the interpretation up to the person who sees it and the culture that has defined it. A rainbow is in fact a full circle of light. However, due to most people viewing a rainbow on the ground we only see a semi-circle or arc of the rainbow. The only way to see the full circle of a rainbow in the sky is to be above the raindrops and have the sun behind you. You would have to look down on the drops from an aeroplane.
Unquestionably everyone will agree that rainbows are one of the most astonishing phenomena associated with light. You can make your own rainbows with a lawn sprinkler or even a water spray-bottle that can make a fine mist. On a bright, sunny day with the sun at your back, spray some water in front of you in different directions to see where the best rainbows can be seen. Ready, set and enjoy …..