Have you ever seen a rainbow? Of course you saw it a moment after the rain falls. What exactly a rainbow? Rainbow is sunlight spread out into its spectrum of colors and diverted to the eye of the observer by water droplets. The same case as a prism does to sunlight.
Sunlight is made up of the whole range of colors that the eye can detect. The range of sunlight colors, when combined looks white to the eye.
A prism is a triangular piece of glass, which allows light to spread out into a band of colors. These colors are red, orange, yellow, green, blue, indigo and violet. When the sunlight passes through the prism, it will break into its composition colors as you can see in the picture above.
What Makes a Rainbow? Or, A Double Rainbow?
When it rains, there are many droplets of rain water in the air. These water droplets acts as prism to refract white sunlight into its colors.
Sometimes we see two rainbows at once, what causes this? We have followed the path of a ray of sunlight as it enters and is reflected inside the raindrop. But not all of the energy of the ray escapes the raindrop after it is reflected once. A part of the ray is reflected again and travels along inside the drop to emerge from the drop. The rainbow we normally see is called the primary rainbow, and another one is secondary rainbow.
Sometimes we see two rainbows at once, what causes this? We have followed the path of a ray of sunlight as it enters and is reflected inside the raindrop. But not all of the energy of the ray escapes the raindrop after it is reflected once. A part of the ray is reflected again and travels along inside the drop to emerge from the drop. The rainbow we normally see is called the primary rainbow, and another one is secondary rainbow.
