A Rainbow in the Sky
A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multi-colored circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.
It also occurs when it is raining in one part of the sky and sunny in another.
The colours of the rainbow are violet, indigo, blue, green, yellow, orange and red. An easy way to remember the colours of the rainbow is VIBGYOR.
It is believed that 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.
Scientist Isaac Newton explained how a rainbow forms. Sunlight is really made up of the colours of the rainbow. When those colours are all mixed together it is called white light. White light is the light we see everyday. When sunlight travels through the air in the same direction we see white light. When the sunlight enters through a raindrop the colours separate causing us to see a rainbow.
Each raindrop makes its own rainbow but it takes millions of raindrops for us to see a rainbow.
A rainbow arch is a 42 degree angle starting from the direction opposite from the sun.
Sometimes sunlight is reflected twice inside a raindrop. When this occurs we get a secondary rainbow or a double rainbow.
The colours of a secondary or double rainbow are in opposite order of the primary or first rainbow. You will see violet on top of the secondary rainbow instead of red.
Moonbows or lunar rainbows occur when the moon's light reflects through the raindrop. This type of rainbow is rare because the moon's light usually isn't bright enough for a rainbow to form.
Did you know that no two people see the same rainbow, why? 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.
When the sun is lower, the rainbow will be higher in the sky.
When the sun is higher, the rainbow will be lower in the sky.
On the ground we only see a semi-circle rainbow but from very high up, such as on an airplane, you can see a rainbow in a complete circle.
Did you know you can never get to the end of the rainbow? When you move the rainbow moves too.