Rainbows Are All Around Us. Water Droplets Bring Out the Colors

Rainbows are the thing of fairy tales, songs, legends and mythology. They’re impossible to ignore when they fill a horizon with brightly curved arcs of red, green and blue. Ironically, they surround us all the time, but they need the moisture of rainy weather to reveal themselves.

The sun bathes the earth in what’s called white light. It contains all colors of the spectrum. We see approximately 100 various shades of the basic six colors in the white light spectrum. The scientist responsible for discovering the colors inside sunlight died 289 years ago this month.

Isaac Newton was an English physicist and mathematician who identified the basic colors carried by light. Newton first identified red, orange, blue, yellow and green. By 1672 he added two more colors to the spectrum—indigo and violet. That amounted to seven basic colors in the light spectrum, but the scientific community discounted indigo as being simply a dark blue. The six recognized colors are what make up rainbows.

Newton based his idea of seven colors on the ancient Greek philosophy that the musical scale of seven notes and the existence of seven days in a week were important influences in scientific knowledge. A brilliant man who lived beyond the average age of his day, Newton died at 84 on March 20, 1726.    

Newton studied light refraction through prisms and concluded that rainbows are the result of light passing through droplets of rain water. The drops of water act like prisms that separate the white light into the primary colors. Each drop of water bends the white light into primary colors. The colors of light have different wavelengths. Red, with the longest wavelength, always shows up at the top of a rainbow. Violet has a comparatively short wavelength and it usually is at the bottom of a rainbow. The curved effect of a rainbow is the result of the different colors bending as they pass through the water droplets.

The main colors in a rainbow are red, green and blue. Red is the dominant color of a rainbow at 38 percent. Green is 22 percent, and blue is 11 percent of a rainbow’s colors. The remaining three colors make up the remainder of any rainbow.   

We see a rainbow when we are between the sun and the water droplets. Usually we see a rainbow against a rain shower. But rainbows show up on the mists of waterfalls, bodies of water and even against thick fog. 

The angle between the sun and the water droplets is critical. In order to see a rainbow, our line of sight must be 42 degrees from the sun to the source of moisture. That’s a critical angle, and that’s why every person sees a particular rainbow differently. If we move only a slight distance, the angle and view of a rainbow changes. While driving in the direction of a rainbow you’ll see that it seems to keep moving.  That’s because our perspective of the light reflection keeps changing as we move.  Rainbows, after all, are just reflections of light and aren’t three dimensional.

Rainbows have mystical stories attached to them. An ancient fable of finding a pot of gold at the end of a rainbow is a make-believe fable based on Irish folklore involving leprechauns. . We never can see the end or beginning of a rainbow because our view is constantly changing by the 42-degree angle from the sun. No matter how far or fast you drive, you’ll never find that leprechaun’s pot filled with gold pieces.

A rainbow is part of a well-known story in the Bible’s Old Testament. In Genesis, we can read the story of a great flood God put upon the earth to punish a sinful population. Noah, our hero, built a large boat, an arc, to save his family. Male and female animals of all the species on earth were contained inside the arc to save them from drowning in the deep water.  At the end of the forty day and forty night flood, the arc landed on dry land, and Noah celebrated with his surviving family.

God promised Noah that the world’s people would never be destroyed by floods again. As a reminder of His promise, God put a rainbow in the sky.

“Never again,” God said, “shall flesh be cut off by the waters of the flood. Never again shall there be a flood to destroy the earth.”

Then God told Noah, “I set My rainbow in the cloud, and it shall be for the sign of the covenant between Me and the earth.”

We can always remember God’s promise whenever we see a rainbow. Its significance is great, but the cause of a rainbow is basic physics. Only three things are needed for a rainbow to appear: One, the sun must be behind you; two, the moisture or rain must be in front of you; and three, the sun has to be shinning.

Thanks for reading this blog. Come back to this space later this month for another interesting subject. Go to my website www.joevlatino.com to learn about my book of short stories, “The Device.”