We are capable of perceiving only a fraction of the electromagnetic spectrum. A quantitative analysis of the different wavelengths at which visible colors are perceived, is presented in this article.
How Do Rainbows Form
Everyone loves rainbows. But how do rainbows form? Have we ever tried to find out? Let’s do it then.
Have you ever had this happen to you? You’re walking down the road, rushing home from work, when a light drizzle begins. You feel elated because while the tiny drops of water feel cold as they fall on your bare skin, you can see and feel the warm glow of the sun, which looks so mellow, far out in the horizon. You want to just run towards it because it looks like a giant marshmallow, waiting to be devoured when suddenly you see something more breathtaking: a rainbow!
The subtle arch of vibrant colors, which appears to go from one end of the earth to the other, beckons you. Just as you come out of the magical trance and take a step towards it, it begins to fade away. And you’re back to feeling that gloom that preceded the wonderful phenomenon that you just witnessed. Rainbows can have that effect on anyone. We all love to watch them, but we never think about how they form. While explanations about the formation of rainbows can range from fairy dust being sprinkled to the fox and vixen getting married on a hill top, the real story behind its formation is quite technical, thus making it a little (dare I say) boring.
The Formation of Rainbows
The process of rainbow formation has been explained in steps for your easy and better comprehension.
- Step 1: The main reason behind the formation of a rainbow, that is the semi-circular band of 7 colors that you see in the sky, is basic physics. Reflection and refraction of light is what causes the formation of the spectrum, which is the breakdown of white light into its basic colors.
- Step 2: In order for a rainbow to be formed, it is necessary for the fundamental components of reflection to be present: light and a reflecting surface. Here, the light is the sun’s rays and the reflecting surface is the drops of water.
- Step 3: When light emanates from the sun, it is in its pure form, i.e., white light. When this white light reaches the surface of a water droplet at the appropriate angle, it breaks down into the spectrum of colors. This spectrum reaches the inner most point at the top of the water drop and gets reflected onto the lowermost point in the drop.
- Step 4: This spectrum gets refracted from this lowermost point, gets dispersed, and escapes the water droplet.
- Step 5: This dispersed spectrum of colors is what we see as the rainbow. An interesting tidbit is that within the droplet, the rainbow colors are in the order of red, orange, yellow, green, blue, indigo, and violet, but when they get refracted and are seen in the sky by the human eye, they are perceived to be in the opposite order, which is violet, indigo, blue, green, yellow, orange, and red. So, the first color in the actual spectrum is seen as the last one by us.
As mentioned earlier, how rainbows form is not at all as glamorous or fantastic as imagined. Nonetheless, we can always continue to indulge ourselves in fantastical beliefs, as long as we know what the truth is.