Rainbow – miracle in the sky
Colorful rainbow in the sky has been astonishing and frightening people since ancient times. The ancient Greeks thought these arcs of color were signs from the gods to warn people that terrible wars or storms were going to happen. The Norse people believed a rainbow was a bridge the gods used to walk down from the sky to the Earth. Irish legends said there was a pot of gold at the end of a rainbow.
But rainbows aren’t magic. It is just colored light. The seven colors are always the same and appear in the same order: red, orange, yellow, green, blue, indigo, and violet.
Rainbows often appear after or at the end of a rain. When a beam of sunlight passes through raindrops, it’s broken into the seven different colors. Because only water and light are required for rainbows, one will see them in rain, spray, or even fog.
Sunlight travels through space in the form of waves. Scientists use an idea called wavelength to describe these waves. Some light waves have long wavelengths, while others have short wavelengths. Light waves with different wavelengths appear as different colors.
In 1637 Rene Descartes first discussed the formation of the arc. 30 years after Descartes Isaac Newton discovered that white light was made up of different wavelengths.
No two people will see the same rainbow.
A rainbow lasts only about a half-hour.
The brightness of the colors of the rainbow depends on the size of the raindrops. Large drops create bright rainbows with well-defined colors.
A full 360° rainbow can only be viewed from an airplane.
In many cultures there are legends and myths about the power of the rainbow, people devote it works of art, music and poetry.
Psychologists say that people admire this natural phenomenon, because the rainbow is a promise of a bright, “rainbow” future.
Rainbow can be seen even at night. This phenomenon is called a lunar rainbow. In this case, the rays of light are refracted by reflection from the Moon.
Twelve colors of rainbow
First of all, nothing affects the human mind more dramatically than the apparition of a gigantic color corona in the heavens. Indeed, thunder and lightning frighten us; but the colors of the rainbow and the northern lights soothe and elevate the soul. Besides, the rainbow is a symbol of peace. However, a new study shows there are actually twelve colors of rainbow. In particular, scientists from the National Meteorological Research Centre in France found: seemingly familiar rainbow can have 12 different versions, each of which has specific characteristics. Also, experts studying atmospheric phenomena explain why sometimes you can see in the sky not one, but two, three or even four identical rainbows. In fact, they are different and become visible due to the fact that the rain drops, which refract and reflect the sunlight moves. Therefore, after watching for a while, you can see how the rainbow is changing.
To classify the numerous observed rainbows, a team of meteorologists has allocated a minimum set of characteristics that are valid for all rainbows. It was found that there are four such characteristics. Some of them have long been known.
Firstly, each rainbow has red color visible above and below – the blue-violet. Secondly, the secondary arc occurring over the first, is less noticeable, colors are arranged in reverse order (top turns blue-violet).
Third, between the two apparent arcs there is so-called band of Alexander – a dark strip of sky. And fourthly, on a second rainbow, under certain conditions can arise even one or two “abnormal.” So, some of the rainbows have no “abnormal”, others do not have a distinct band of Alexander, and others do not contain all the colors of the spectrum. As a result, depending on the combination of different characteristics can be observed 12 types of the rainbow.
Meanwhile, a key factor in determining the type of each rainbow is the position of the sun in the sky. For example, when the light is low on the horizon, you can see only a red arc. A droplet size determines the width of multi-colored stripes.
It is known that the rainbow has no beginning or end, and a closed curve. However, it can be seen only under certain conditions that develop very rarely. Usually people see a rainbow in the shape of an arc.
Misty rainbow, or fog bow – a very rare phenomena. It occurs when the sun’s rays illuminate a light mist of tiny water droplets – smaller than those that form normal colored rainbow. Externally similar to the misty rainbow halo, though its nature varies. Halo usually occurs in the winter around a powerful light sources such as the sun or the moon, when light rays are refracted in the tiny ice crystals, so-called diamond dust. Usually halo is slightly colored, but sometimes decomposed into a spectrum – a phenomena called the winter rainbow. Misty is always a rainbow almost colorless.
ACV = All Colors are visible SUP = Supernumerary Bows are present
The supernumeraries are the closely spaced greenish purple arcs on the inner (blue) side of the primary bow
SAB = Strong Alexander Band no SUP = no Supernumerary Bows are visible
WAB = Weak Alexander Band Only 6 colors are considered = Violet, Blue, Green, Yellow, Orange and Red.
Sources:
dailymail.co.uk/sciencetech/article-3366474
vokrugsveta.ru/news/241786/