A Description of the Formation of the Rainbow

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A Description of the Formation of the Rainbow

Historically, Aristotle (the classical Greek philosopher) was the first person to devote much effort in studying the rainbow. Despite its appeal to the Pythagorean numerology, his qualitative explanation of the rainbow was relatively consistent and remained unchallenged for centuries. It was not until his death that more scientific theories about the rainbow got formulated. The early scientific explanation coined by Hüseyin Topdemir Gazi, the Persian physicist, asserted that a rainbow is a concentric circle that forms on the axis of concave mirrors. His theory was founded on the refraction and reflection of the sun rays. A number of modern scientists relied on these two scientific principles in advancing the rainbow formation experiments. This research focuses on the dispersion, refraction, and reflection of light as the primary processes involved in the formation of the rainbow.

The rainbow is a multi-colored spectrum of light meteorological and optical phenomenon caused by refraction and reflection of light rays in water droplets. The formation of the rainbow takes place in seven stages. In the first stage, white light produced by the sun strive the raindrops at an acute angle before any light spectrum forms. The angle at which the white light rays from the sun hit the drops of water in the sky is important. It is because this determines the direction of the refracted and reflected light rays after hitting the water surface, thus playing a decisive role in the formation of the rainbow (XXXXX).

The second and the third stages of this scientific process are reflection and refraction of the white light rays respectively. Like a glass window, water reflects and transmits light. When the white light rays radiated by the sun hit water droplets in the sky, a fraction of these light gets reflected in accordance with the laws of reflection (XXXX). Some white light rays get refracted, thereby crossing the air-water boundary layer. However, they slow down in speed because of the differences in medium densities. Therefore, the light path bends upon entering a denser boundary – a process referred to as refraction of light. It is this bending of the white light toward the normal line that gets directed into the eye of the observer (XXXXX).

The fourth stage involves the splitting of the white light into seven component colors. XXXXX (…) established that the white light is a spectrum of different colors and wavelengths. They include red, orange, yellow, green, blue, indigo, and violet (ROYGBIV). Depending on their wavelengths, these colors have different speeds when they travel from one medium to another of different densities. It is these variations in densities that determine their degrees of dispersion. However, the rainbow remains invisible to the viewer unless total internal reflection takes place. This happens in the fifth stage of rainbow formation. In this stage, the white light hits the raindrop surface at the incident angle that exceeds the theoretical critical angle (XXXX).

The final two stages are double refraction and further dispersion of these light spectrums. The speed of the white light changes again for the second time when it leaves the raindrop boundary. Given that it enters a lighter medium (air), its speed increases and it gets refracted away from the defined normal line. Each component of the white light is further dispersed depending on its wavelengths, thereby forming a circular arc. The red light gets refracted away from the normal line at a steeper angle relative to the blue light. It is for this reason that the red light gets directed to the eye of an observer standing at an acute angle to the ground. The blue light is directed at obtuse angle through a trajectory path that passes over the head of the observer. This is why the red and blue lights are observed at the top and bottom of the rainbow respectively.

In conclusion, the formation of the rainbow is one of the scientific processes that have remained controversial. While Aristotle proposed the first theory explaining its formation, it got dismissed on the account that it was a qualitative to this scientific process. However, most scientists relied on this theory to advance scientifically proven explanations about the formation of the rainbow. There are three processes involved in the formation of the rainbow. These include reflection, refraction, and dispersion of the white light, which is a spectrum of seven light colors. Before the rainbow forms, the white light radiated by the sun and water droplets must exist. Depending on their wavelengths, different components of the white light get dispersed and refracted at different angles away from the normal line, hence the formation of the rainbow.

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