The rainbow is one of God’s most adored creations, perhaps due to its multiple colors and unique shape. In most traditional societies the rainbow is used to convey information about the changes in weather. For instance, some African communities believe that if a rainbow appears in cloudy weather, chances of rainfall are narrow. Therefore, this paper will shed light on the logic behind the formation of rainbows, and also where the colors come from and the shape of the rainbow.
How the Rainbow is Formed
According to Lee and Fraser (2001), the earth, just like the other planets, relies on the sun for lighting purposes. The rays of the sun that are emitted towards the earth are comprised of multiple colors, such as green, red, and yellow, among many others. When the rays of sun land on the surface of the earth, they cause the temperatures of the earth to increase, leading to evaporation of water in the water bodies such as rivers and lakes.
When the water is evaporating, and by any chance it comes into contact with the rays of the sun, that is when the rainbow is formed. When the sun rays land on any given water particle, the multiple colors are dispersed. Since water is opaque, it allows the sun rays to penetrate and exit on the rear end of the water particles.
However, there are some rays that are bent by the water particles and the light that is bent is what is seen as the rainbow. The sun releases the rays in wavelengths: the sun rays are emitted in varied wavelengths, meaning that they travel at different strengths. Therefore, the strength of the wavelength is what dictates the color to be assigned to any given ray.
The Colors of the Rainbow
The sun is a million miles away from the earth, but amazingly the rays that are emitted are parallel to one another and the space between them can never be overlapped until they land on an object. Topdemir (2007) explains that the rays that have short wavelength are blue, and alternatively the rays that have long wavelength are red in color.
Moreover, the bending of sun rays is influenced by their wavelength. In fact the colors that we see in a rainbow are not all because the ones that are not strong enough are not bent, and thus they are not displayed in the rainbow. Usually, the rainbow has seven colors: red, orange, yellow, green, blue, indigo, and violet.
Rainbows are usually visible during the day towards the evenings, and maybe if the clash between the sun rays and water particles took place before afternoon, say like at around lunch time, it would not be possible for us to see the rainbow. The timing of a rainbow is very crucial because towards the evening the sun is usually headed to the east, thus its rays do not cover the entire surface of the earth. The position of the earth causes the rays to be bent 42 degrees upwards on landing on water particles.
The rainbow is usually displayed directly opposite the sun, and the viewer is normally in the middle. This is influenced by one’s location, but surprisingly we all see the colors differently. This can be explained by the fact that some people are color blind, and thus they can only identify less colors.
In addition, the people on the ground can only see one half of the rainbow, and that is why most people argue that its shape resembles an arc. This is not true because what hinders them from seeing the complete rainbow is the ground. Those who have viewed it from an aerial view, especially when in a plane, can testify this because they are able to see the complete rainbow circle (Dong, 2000).
The Shape of the Rainbow
The rainbow has a curved shape because the sun rays are blocked by the earth’s horizon, and since it is obvious that the shape of the earth is spherical – this is a reasonable logic that is beyond doubt. This is because during the formation of the rainbow, the sun is usually about to set, hence its position is lower than that of the earth.
To prove this argument is true, an experiment involving a medium sized spherical object like a pumpkin, and a source of light like a torch provides the same results. This is achieved by lowering the position of the torch, while the light is directed towards the spherical object and the end result is a spherical shadow (Topdemir, 2007).
Types of Rainbows
At times, the rainbow is displayed in a pair of two rainbows, which is commonly called a double rainbow. In such case, one rainbow is thicker than the other, and this happens to be the outer rainbow. According to Dong (2000), the outer rainbow resembles the inner one, only that its colors are not bright compared to the inner rainbow. The formation of double rainbow is exactly the same as the formation of a single rainbow.
However, the difference comes in how the rays are bent by the water particles because here, bending of sun rays occurs twice and simultaneously. The angle of bending the rays occurs at 53 degrees. In a double rainbow, there exists a space between the two arcs called the Alexander’s band which looks darker, probably due to insufficient lighting. A keen observation of the arrangement of colors in the outer rainbow reveals that its colors are inverted.
In addition, a supernumerary rainbow is formed when there are less water particles in the atmosphere. This is probably due to the decline in the size of water drops. Here, several arcs that are formed behind the primary arc. The primary rainbow increases in width and its colors become lighter.
With time the arc becomes more of a fog than a rainbow. Supernumerary rainbows are said to be caused by downpours that have drops of varied sizes. It is certain that the drops of the primary arc have individual colors than those of the adjacent arcs.
Lynch and Livingston (2001) outline that when a rainbow is displayed over the surface of water, such as above the lake or the sea, there is a reflection of the original rainbow. One arc is caused by the deflection of the water on the sun rays, but the main challenge is identifying the primary arc and the reflected arc.
The reflected rainbow is normally placed above the primary arc. During the formation of this rainbow the rays of the sun land on the surface of water which then deflects them until they land on water particles in the atmosphere. The arcs meet at the horizon, but as they stretch outwards they appear to be parallel, which is not true.
The other type of rainbow is called monochrome, and is common at sunset or sunrise. During such instances, the sun rays are said to be unable to reach the surface of the earth and the only rays that are visible are the ones that have long waves, probably the red colored ones. At sunset and sunrise, the sun is completely invisible.
The rays that have short wavelengths cannot be seen, and that is why the rays have one color. However, the other colors are present, but we cannot see them with our natural eyes. When these long wave rays converge with water particles in the atmosphere, a monochrome rainbow is formed.
Myths Involving the Rainbow
There are various myths surrounding the formation of the rainbow, and they vary from one community to another. Among the Greeks, the rainbow is perceived to represent a footprint left by god’s messenger, commonly known as iris. In this community, the messenger walks along the rainbow to reach the earth, thus it acts as the bridge between the two worlds.
Likewise, the Chinese mythology dictates that the rainbow is a gap that was present in the skies and it was repaired by a female divine being by sealing it with stones of varied colors. Among the Hindu, the rainbow is expressed as the bow that is owned by the god of lightening Indra (Lynch & Livingstone, 2001).
Kunchinsky (2007) states that others still believe the rainbow is holy because they assume that the gods store their valuable possessions at the end of it. The mystery here is reaching the end of the arc which is not possible because as one moves towards the arc, it appears to be moving away.
Some ancient people perceive it to be a necklace that belonged to a female divine being. Among the Christians, the rainbow represents the agreement that God made with Noah after the end of the greatest rainfall that killed both humans and animals. According to biblical scriptures the rainbow acts as a reminder to God that He made an agreement with humans not to use water to eliminate them.
The myths surrounding the rainbow are endless, but most people adore it because of its beauty; the colors of the rainbow. It is in this regard that renowned painters such as Albretcht Durer and Joseph Anton Koch have integrated the rainbow into their artworks. In literature the rainbow is said to invoke and give an impression of simile and metaphor.
Perhaps that is why renowned poets like Virginia Woolf and John Keats incorporated it into their pieces. In textile industry there are numerous fabrics that apply the concept of the colors in the rainbow. Furthermore, that flags that have the rainbow colors are used by activists to advocate for change. Therefore, rainbows are among the natural phenomenons which depict the beauty of nature.
Dong, P. (2000). China’s Major Mysteries: Paranormal Phenomena and the Unexplained in the People’s Republic. San Francisco: China Books and Periodicals Inc.
Kunchisnsky, C. (2007, December 7). The Rainbow & the Various Myths Surrounding It. Retrieved from http://www.associatedcontent.com/article/466052/the_rainbow_the_various_myths_surrounding.html?cat=34
Lee, R. L. & Fraser, B. A. (2001).The Rainbow Bridge: Rainbows in Art, Myth and Science. New York: Pennsylvania State University Press.
Lynch, D. K. & Livingston, W. C. (2001). Color and Light in Nature (2nd ed.). New York: Cambridge University Press.
Topdemir, H. G. (2007). Kamal-Al-Din Al-Farisi’s Explanation of the Rainbow. Humanity and Social Sciences Journal, 2 (1), pp.75-85.