What Makes a Rainbow

Here we will explain to you what makes a rainbow, some related facts, and also guide you to make your own rainbow using some household stuff.
ScienceStruck Staff
Last Updated: Jul 4, 2018
Rainbow On A Cloudy Blue Sky
Rainbows appearing during the rain after the rains or due to mist are a beautiful natural phenomena. One can see the beautiful seven colors that it comprise, across the sky after or during the rain and when the sun is present as well.
We get to see this naturally-occurring miracle, though quite rarely. However, it is possible for you to watch these seven colors at home with some simple experiments. This write-up tells you what makes a rainbow, along with some interesting facts and simple experiments you can conduct at home.
What Makes a Rainbow in the Sky?
  • In the year 1666, Sir Isaac Newton discovered that sunlight falling upon a prism can be split into its component colors. This process is known as dispersion.
  • Then, Newton named these components as red, orange, yellow, green, blue, indigo, and violet. This band is known as the spectrum, and these are the colors of the bow, in order.
Crystal Prism
  • They are quite easy to distinguish, except for indigo.
  • In the prism experiment, white light gets dispersed in such a way that it produces the seven colors.
  • In the very same manner, this natural phenomena occurs.
  • Ordinary white light (or light form the sun) is made up of a number of colors of different wavelengths.
  • When it rains, the atmosphere gets filled with raindrops. These raindrops act as a prism.
  • When sunlight passes through these raindrops at a specific angle, the light gets split into the spectrum, which is made up of the various colors. And thus, we get to see this lovely sight.
Interesting Facts
  • A rainbow similar to music is made of the same stuff, except for vibrating at a different frequency.
  • Its true shape is a complete circle.
  • When it is viewed from a plane, one can see the entire circle, as you will be able to look down on raindrops as well as up to them.
  • The angle of light refraction is 42 degrees to the eye of the observer.
  • Many people think it contains only red, orange, yellow, green, blue, indigo, and violet colors. However, it is actually made of an entire continuum of colors, some of them, which cannot be seen with our ordinary eyes.
  • Iris is the Greek goddess of rainbow.
  • It can be viewed by every person as their own. This is because, when you are looking at it, you get to see the light reflected off certain raindrops, but when a person next to you gets to see the same sight, the light reflection angle is changed, and he sees his own personal view of this colorful splendor.
  • It has a very relaxing effect and healing qualities.
  • There is a rare natural phenomena called fire rainbow, in which you can see all the colors, but the shape resembles fire flames instead of an arc. You can find its pictures on the internet.
Making Your Own Rainbow
Here are three experiments, which you can perform at home easily, and see this beautiful phenomena.
Using a CD
Blue CD
Take a clean CD and place it label side down. Look at the CD under a light, and voila! You get to see the colors, and you can keep tilting the CD to see how the colors keep shifting with the angle.
Using a Sunny Window
Sunny Window
Fill a clear glass with water. Place it on a table, which is in front of a sunny window. Then, place a sheet of white paper on the floor. Wet the window with hot water, keep adjusting the glass and paper till you get to see the soothing sight.
Using a Water Hose
You need to perform this experiment on a bright, sunny day. Stand with your back against the sun, and hold the water hose in your hand, create a mist by placing finger over the water hose. Continue looking at the mist to see the colors.
Hope this write-up cleared your doubts on rainbow and how it occurs. So, perform the given experiments to see the beautiful spectrum of colors yourself!