HOW DO RAINBOWS FORM ?

What are rainbows ?

A rainbow is a colourful arc made of 7 colours. The colours are red, yellow, green, blue, indigo and violet, in short form VIBGYOR. Rainbows can be seen in two shapes, an arc or semi-circle and a full circle which is very rare compared to an arc. Though we mostly see only an arc, a rainbow is always a whole circle.  Rainbows mostly appear in morning or late afternoon, when it is sunny as well as raining at the same time, mostly in monsoon season after a rainstorm. 

How do Rainbows form ?

When sunlight passes through raindrops, the light bends, or refracts, as it enters the droplet, and then reflects off the inside of the raindrop. This happens because the water is more dense than the air that surrounds it. As it exits the droplet, the light separates into different colours and it then forms a part of the rainbow. Sunlight actually contains millions of colours but it is just simplified as 7 colours. Though we see that light is white in colour, it actually is made up of seven different colours and all the colours have different temperatures at different times!! This whole process is called the dispersion of light.  

Interesting facts on rainbows

• Do you know who discovered the formation of rainbows?

  It was Sir Isaac Newton, as he was the first one to discover that light when bent or refracted and then reflected forms many colours!! 

• Can we touch a rainbow? 

  No, as it is just refracted light which we can see, not touch. 

• Can everyone see the exact same rainbow? 

  No, as the other person is standing in a different direction, so he/she sees different shapes of rainbows.

• When and where did the longest lasting rainbow occur? 

  It occurred on November 30, 1994 in Taiwan, China above Taipei's Chinese culture university for exactly 8 hours and 58 minutes. 

• Can rainbows occur in the night? 

  Yes, rainbows can be caused by night rain with the light of the moon and the stars but it is very rare. 

• Where do rainbows most commonly occur? 

They mostly occur in the state of Hawaii than anywhere else on Earth.  

Why are rainbows curved or spherical in shape?

The rainbow is curved as it reflects the round shape of the Sun. Rainbows are circular because raindrops are spherical in shape. 

What causes the VIBGYOR sequence of colors in a rainbow?

This depends on the wavelength of the colors. Red has the longest wavelength and then the wavelength of each color is lesser than red. Violet has the shortest! So when the light passes through the rain droplets, violet light will bend more than red. This will make red and violet sit at opposite ends of the rainbow. 

Why does a rainbow appear after rain?

The rainbow effect can be observed whenever there are water drops in the air and sunlight shining at a low angle from behind the person trying to observe the rainbow. The most spectacular rainbow displays when half of the sky is still dark with draining clouds and the observer is at a spot with clear sky overhead. The rainbow effect can also be commonly seen near waterfalls or fountains.

The rainbow can also be artificially created by dispersing water droplets into the air during a sunny day. So friends, would you like to try this out? Please do so and share your experiences with me.

A rainbow is a natural phenomenon which makes everyone happy and curious to know how it forms. It is also a beautiful sight to see a rainbow because of its amazing and colourful beauty.