Introduction
Children always wonder why the sky is blue and where the rainbow comes from. Perhaps, each of us passed through such a period in our early years. There is no doubt that our parents put a lot of effort and creativity to explain these rather complicated matters to us, and, of course, those answers were tenuous in a certain sense as children are not able to comprehend several complicated matters. As a result, people stay curious, in a way, as to the nature of such phenomena as color distribution in the surrounding world and rainbow nascence along with the factors causing it. In the following paper, these two issues will be examined in terms of their connection to the phenomena studied by natural sciences such as light diffraction and scattering. Overall, studying the facts shows that the matters related to the color of the sky and the emerging of the rainbow are explained by several physical laws along with biological peculiarities of the human eye formation which is responsible for visual perception.
What causes rainbows?
A row of complicated physical phenomena lies based on rainbow appearance in the sky. First, this is the phenomenon of splitting white sunlight into its components of all the colors of the spectrum. This phenomenon occurs in the raindrop under the influence of optical laws. In this vein, the light which appears in the raindrop is reflected by its sides, and as the raindrop has a rounded form, the light is divided into reflected smaller lights that have different lengths under the influence of the diffraction phenomenon. lights of different colors are produced as a result. These lights form the rainbow perceived by human eyes. This is how this phenomenon is described in The Columbia Encyclopedia (40388), “the light is refracted as it enters the sphere of the individual water drop, then is reflected from the drop’s opposite side, and is again refracted as it leaves the drop and passes to the observer’s eye”. Human eyes’ features and formation, in a way, are also related to seeing a rainbow in the sky. As human eyes are designed with the ability to percept or see only those lights which are reflected from different surfaces, they see assorted colors. Different colors are explained by different lengths of lights reflected from varied surfaces (“What causes a rainbow?” par.4). Hence, the way the human eye is built is also connected to the phenomenon of seeing a rainbow. Due to the phenomenon of light dispersion, water drops reflect all the colors of the spectrum. As a result, the human eye percepts many colors forming the simulacrum which received its title of “rainbow”. If our eyes were designed in some other way, who knows would that be possible to see beautiful rainbows as we see them with our eyes.
Of course, the explanation discussed above is a basic explanation that can be found in numerous encyclopedias to give the audience a general understanding of rainbow-related matters. However, to deepen such understanding, it is important to address the very formation of color prism along with what is happening inside it when white light becomes separated into many other colors. According to “What causes a rainbow?” (par. 7),
The dispersion of colors in a prism occurs because of something called the refractive index. Every material has a different refractive index. When light enters a material (for example, when light traveling through the air enters the glass of a prism), the difference in the refractive index of air and glass causes the light to bend. The angle of bending is different for different wavelengths of light. As the white light moves through the two faces of the prism, the different colors bend different amounts and in doing so spread out into a rainbow. In a rainbow, raindrops in the air act as tiny prisms.
This is a very important point understanding of which is necessary for understanding the very phenomenon of seeing a rainbow. Light dispersion causes the formation of smaller lights of different lengths. The lengths of these lights are responsible for color distribution among these lights. Water has a rather significant refractive index which explains the fact that the rainbow has so many nice colors and can be seen in huge sizes even under the condition of being far away from the observer’s location (“What causes a rainbow?” par.8).
Why is the sky blue?
The question of why the sky is blue is connected to the very similar phenomena of optic nature and the peculiarities of human eyes’ building. Their foundation lies in the phenomenon of light diffraction and color perception by human eyes. Here is the way this phenomenon is explained in The Columbia Encyclopedia:
The blue color of the clear daytime sky results from the selective scattering of light rays by the minute particles of dust and vapor in the earth’s atmosphere. The rays with longer wavelengths (the reds and yellows) pass through most readily, whereas the shorter rays (the blues) are scattered. An excess of dust, especially in large particles, causes the scattering of many rays beside the blue (45070).
These few sentences explain very complicated phenomena standing behind the color of the sky as it is perceived by human eyes. Below, these few sentences along with the important facts they depict will be discussed in detail.
Again, to understand the reason of sky is blue, it is important to understand the nature of light. Light is a kind of electromagnetic energy represented in the form of waves possessing both magnetic and electric properties (“WHY IS THE SKY BLUE?” par.4). Some of these properties are the length of these light waves. Depending on the length of every particular light wave, the observer sees it as blue, yellow, red, or as any other color (The Columbia Encyclopedia 45070). Blue waves are the shortest light waves from the whole spectrum (Reilly par.3). As a result, they are scattered in the atmosphere more than the other light waves which are absorbed by it. It should be also stated, of course, that violet lights also have this peculiarity. However, the human eye, observing only the scattered lights when seeing the sky, tends to accept blue waves rather than violet ones (The Columbia Encyclopedia 45070). As a result, people perceive the color of the sky as blue. All in all, the reason why people see the color of the sky as blue is in blue rays are the shortest rays which explains their tendency to scatter in the atmosphere and be perceived by human eyes.
Conclusion
Concluding on all the above-discussed information, it should be stated that phenomena of the world around us conceal numerous secrets and complicated matters for a layperson. However, in case one acquires a basic understanding of the physical, optical, and biological matters, these secrets become rather explainable and comprehendible. In particular, behind all the issues of color perception by human eyes stands the theory of light as a form of electromagnetic energy represented in waves of different lengths. Depending on the length of such light ray or a wave, the human eye sees it as blue, yellow, red, or as any other color. Further, almost all the objects of the material world such as air and raindrops have a feature of reflecting light waves. Varied materials reflect different lights in different ways. People see only those objects which reflect light waves, and these objects are seen as being of the color they reflect. When the human eye sees the sky, the waves it percepts are the shorter ones, and they are blue. When the human eye observes the sky after the rain, it can see the waves reflected by the water drops. Due to the phenomenon of light dispersion, water drops reflect all the colors of the spectrum. As a result, the human eye percepts many colors forming the simulacrum which received its title of “rainbow”. Given these points, the issues related to color distribution among the objects of the surrounding world should be approached from the point of view of light theory and the peculiarities of human eye formation.
Works Cited
“Rainbow.” The Columbia Encyclopedia. 6th ed. 2009. Questia. Web.
“Sky.” The Columbia Encyclopedia. 6th ed. 2009. Questia. Web.
Reilly, Michael. No, Seriously, Why is the Sky Blue? n. d. Web. 2012.
What causes a rainbow? n. d. Web. 2012.
WHY IS THE SKY BLUE? n. d. Web. 2012.