What’s in a Rainbow?

Moving as fast as my feet could possibly take me, I ran, making sure I kept my eye on the end. I had to know what was at the end. Through backyards, over fences and only pausing to look both ways before crossing a street, I made my way. Creek crossings or my neighbors’ aggressive Pomeranian blocked my path. Both daunting road blocks, but nothing was going to stop me. I ran until my legs felt like cinder blocks and my little lungs were on fire. The rainbow wasn’t anywhere closer to me than when I began my expedition. It was time to head home and rethink my options.

I was never motivated by gold and really had no desire to end up in a field of wildflowers. I suppose it was just curiosity to figure out which story was true. It was a growing curiosity that was constantly filled with tales from classmates or family members about what exactly I could find at the end of one of these colorful sky slides. I heard things ranging from pots of gold, fields of flowers and, my personal favorite, a field of Skittles candies. I don’t know if I actually believed any of these theories, but I had to get to the end of one myself. I had to know. 

From that point forward, I devoted my life to figuring out what exactly was in a rainbow and what lay at the end of one. Luckily for me, I didn’t have to spend too much time to get to the bottom of this vibrant mystery. After some time spent in the library, and talking to some of my science teachers, I had my answer. Not only did I have my answer, but I also learned how I could make my own rainbow from the comfort of my own home! Here’s the deal:

What is in a rainbow?

Rainbows don’t actually contain anything tangible. That is to say, you can’t go and grab a rainbow. That is because rainbows are made up of visible light that has been warped by water droplets in the air. When there is moisture in the air, like after it rains or near a large waterfall, light hits the water droplets and is both refracted and reflected to form a rainbow. When the light first enters the droplet it is refracted or bent. It is then reflected, or bounced off of, the back of the particle and then refracted again as it goes back out. We see the colors of the rainbow (red, orange, yellow, green, blue, indigo and violet) because of the angle that each color’s wavelength is reflected. When we look up at the sky normally, we see what is referred to as white light, or all of the colors of the rainbow blended together. Since they all reflect at different angles, they become separated when they hit the back of the water droplets and we are left with a beautiful rainbow. 

What lies at the end of a rainbow?

To keep a long story short, there is no end to a rainbow. A true rainbow is really a full circle. We don’t see it when we are on the ground because of the horizons. However, under the right conditions, a full rainbow can be seen from a perched window seat in an airplane. 

How can I make my own rainbow?

There are many ways that you can make your own rainbow at home. Below are a few simple methods that can be done with materials you have around your house!

Method 1

  • Materials Needed: A half full glass of water, a white piece of paper and a sunny spot at home.
  • Procedure: Place the white piece of paper in a sunny spot at your home. In front of a bright window works best – the brighter the better. Slowly place your glass of water down on the paper. Did you see it? If not, you may need to raise your glass up a little or tilt it in the direction of the sun. Once you’ve got your rainbow, count how many colors you can see. Do you have all seven of them? 

Method 2

  • Materials Needed: A bowl, water, a small mirror, a white sheet of paper and a flashlight. 
  • Procedure: Fill up your bowl with water until it is half full. Place your mirror half way in the water and half way out of the water. Have one person shine the flashlight on the bottom portion of the mirror. Have the second person catch the reflected light on the piece of paper opposite of the mirror. Do you see the rainbow? You may have to adjust the angle of your mirror, or how close your paper holder is standing to get it just right. Once you’ve got your rainbow, how many colors do you see? Do you have them all?

Even though there is no real end to a rainbow, it’s always a wonder to take in these prismatic beauties.

Will Buelsing
Nature Interpreter, Miami Whitewater Forest