By VICTOR C. ROGUS
Arcadian Science Editor
We have all seen rainbows and heard legends of pots of gold at the end of them. And with all the recent storms and hurricane activity, double and even triple rainbows have been common.
But science tells us that rainbows have no beginning or end. In fact, they are circular. But we can only see an arc of one at any given time. Rainbows are created by the refraction of light through millions of raindrops in our atmosphere. Rainbows can only appear when the sun is behind us and is low on the horizon. The colors of a rainbow are created by the dispersion of sunlight, causing the spatial separation of white light into components of different wavelengths of colors. The colors are red, orange, yellow, or ROY, green (G.), or blue, indigo and violet, or BIV. An easy way to remember these colors in order is to remember the name Roy G. Biv, a fictional character whose name is forever associated with the colors of the rainbow.
A second rainbow can occur at times when light is refracted twice in raindrops. The observer sees two different refractions coming from different angles. This phenomenon of a second rainbow creates a reversing of the order in which the colors are observed, or VIB G. YOR. However, double rainbows are not particularly rare.
Rainbows—the Latin term is rainy arch—only appear when the sun is low on the horizon, therefore they are most common in the last four hours of sunlight. The lower the sun is in the sky, the higher the rainbow will appear to an earthly observer. When a rainbow appears in the sky, it will seem slightly different to two observers in roughly the same location. This is because the observers see light refracting through a different set of raindrops!
Another phenomenon is an upside-down rainbow. This is different from your typical rainbow, as it is caused not by raindrops but by ice crystals high in the atmosphere. Seen mostly in northern latitudes, upside-down rainbows are rather rare.
Yet another quite rare weather occurrence is a triple rainbow. They are so rare that prior to a photo made in 2011 there have only been five confirmed sightings in the past 250 years!
Aside from Hawaii, the Great State of Florida has produced some of the most beautiful rainbows I have ever seen. In the three years I lived in Arcadia, I learned of the afternoon rains that were common and the stunning rainbows that often followed. Weather in Florida skies can offer some amazing opportunities to study, or to build a fine photographic portfolio.
Wide-open spaces and low horizons around Arcadia and the beaches such as Siesta Key in Sarasota are something to take advantage of, something I must seek out here in Arizona.
Best of luck, Arcadians—may the pot of gold find you!