The Anatomy of a Rainbow

Everyone new to the islands is always awestruck and captivated when seeing their first tropical rainbow. The colors are more vivid, vibrant, and rich than anywhere else, and there seems to be a living presence found in every rising tread and terrace in the bridge in the sky.  

Always and forever on Marco Beach, there have been summer afternoon thunderstorms so dramatic, and so filled with shock and awe, that everything but time stops to take notice. Early morning storms in the rainy season are different. A subtle grace and determination arrive with the morning thunder that portray the inevitable like an opera in the clouds. When a rainbow appears, there is a unique reminder to live in a moment of wonder and perhaps become inspired.

When the magic does occur and the animated colors arch and bridge the clouds, all the Beach Boys and Girls have always stopped to admire the creation and consider the cause and effect of Mother Nature’s artwork.

Every culture since antiquity has a myth or legend about the rainbow and as our weeks of summer progress, and as rising thundershowers set the stage, rainbows arch over Marco and pour a colorful but elusive light that has mystified humanity for centuries.

In Greenland, the Eskimos believe the rainbow is the hem of God’s garment. In Bavaria, the southern Germans believe the saints travel through a rainbow as they pass between heaven and earth. Another suggests a rainbow appears when Saint Peter opens the heavenly gates to admit another worthy soul. Old Norse legends relate that beloved passed-away pets are waiting on the other side of the rainbow for their masters to come home.

Most everyone knows that an Irish leprechaun waits at the bottom of a rainbow watching over his legendary pot of gold and that Judy Garland sang “Over the Rainbow” in the Wizard of Oz. In our present culture, the image of a rainbow signifies everything from peace and goodwill to significant others of the same sex. One ancient tale claims that if a man crosses through the gate of a rainbow he is transformed into a woman; when a woman crosses, she becomes a man.

Many of the old European legends still abound and have roots in modern folklore, but no matter which of the old colorful tales is a favorite, modern science explains the cause and effect of the painting on Mother Nature’s canvas.

A unique mixture of sunlight and misting rain combine to make rainbows. When white light passes through a prism—a cut glass object with pyramid shape—the light turns and reveals the component colors we see in a rainbow. Sunlight is made of light waves that all have different frequencies. When millions of water droplets catch the sunlight, the different frequencies hidden in white light begin to turn at right angles and slow down. Every color we see in a rainbow belongs to a different frequency of light and the different frequencies move at different speeds. All the colors of the rainbow are contained in a light spectrum. Violet and red are at opposite ends of the light spectrum and appear as different colors because they travel at different speeds.

As we stand and observe a rainbow, we are looking at an incredible combination of uncountable raindrops. From the observer’s point of view, the colors of the rainbow come from raindrops at different heights. Higher raindrops will catch and slow down the sunlight and refract the color red to the observer. Raindrops that are lower in the sky will not show the color red but will refract violet. All the raindrops between the higher reds and lower violets will refract and create the different color bands we see in a rainbow. If the observer were above the rainbow, the bands of colored light would form a complete circle.

 Ground level observers only see the bending colors arching up from the horizon because the earth gets in the way. When the sun is lower in the sky, ground-bound observers see a higher arch and more of the full circle - this is why morning rainbows are so intense and dramatic.

When the sun is higher, a smaller rainbow will appear. Single rainbows occur when the raindrops reflect the sunlight once. Double rainbows appear when the raindrops reflect the sunlight twice. Normally the second rainbow will appear slightly fainter, and because of the double light reflection, the color bands will appear in an opposite sequence with red on the bottom and violet on top.

Some of the best and most colorful rainbows appear over Marco, Goodland, and Isles of Capri with classic early morning thundershowers. When those classic colors appear that do bridge the sky, observers from Marco will believe the pot of gold and end of the rainbow is landing on the Isles of Capri. Visitors on Capri will believe the leprechaun, the gold, and the sparkling end of the rainbow rests on Marco. Goodland observer’s might consider Old Marco Village or Caxambas to be the start or the end of where the legends begin, but any true Marco Beach Boy or Girl will recall their first tropical rainbow and how when we first found the gold, it is the place we now call home.

Tom Williams is a Marco Islander. He is the author of two books: Lost and Found and Surrounded by Thunder - the Story of Darrell Loan and the Rocket Men. Both books are available on Kindle and Nook.