Introduction
Explanation of the mechanism of natural phenomena from the point of view of scientific concepts is of great importance for the academic community, as it helps to establish the essence of the world systems organization. Thus, even behind the most unobvious appearances, such as the color of the sky at different times of day, there are complex physical and chemical processes. An in-depth study of these mechanisms largely determines the extent of understanding natural changes and allows manipulation of this knowledge to predict specific results. Thus, the phenomenon of sky coloring at different times of the day is traditionally associated with the physical phenomenon of scattering the light beam emitted by the Sun. This paper will discuss in detail the mechanics of this process and demonstrate why the change in time of day, which is equal to a change in the position of the planet around a star, affects the color of the sky. The purpose of this work is to summarize the available data on the physical component of light scattering in the context of determining the causes of blue and reddish-orange sky color.
Background Information
The uniqueness of the compositional structure of the planet Earth is determined by the sufficient distance from the system-forming star, the Sun, which determines the possibility of the existence of the atmospheric layer. In other words, if the Earth were closer to the Sun, as is typical, for instance, of Mercury or Venus, the atmosphere of the celestial body would be eliminated due to the strong radiation wind emitted by the star and high temperatures. Thus, planet Earth has a gas shell rich in chemical elements: the basis of the atmosphere is molecular nitrogen, N2, (78%), oxygen, O2, (21%), argon, Ar, (0.93%), carbon dioxide, CO2, (0.04%), and other gases (<0.03%) (Sharp, 2017). In combination with a huge number of water molecules, atmospheric chemicals form a grandiose set of compounds inhabiting the Earths gas layer in a heterogeneous manner. It is these molecules that, together with the environment, form a suspension composition of variable density, which becomes the main obstacle to the sunlight.
Of great importance in the discussion of this physical phenomenon is the recognition of the fact that light has a dual structure. Although this has been a debate in the scientific community for centuries, modern science clearly recognizes that light is both a particle and a wave, which defines the dualistic properties of electromagnetic radiation (Rashkovskiy, 2016). As a wave, light has its own wavelength, can create phenomena of diffraction and interference when interacting with obstacles. At the same time, as a particle, light is a flow of photons that propagates in a straight line from source to object. Taken together, both properties produce a combination of particle and wave effects, making the light beam a unique phenomenon that can also be dispersion.
It is necessary to discuss further what the nature of color is and how light is associated with a variety of observed tones. The observed white light itself is a mixture of all available color variations, including red, green, and blue, on which all other shades are integrated. White light can be subject to physical dispersion, resulting in a decomposition of the spectrum, as illustrated in Figure 1. It is known that the difference between colors is the length of the corresponding waves ( Visible spectrum, 2019). Thus, a good example that justifies this effect is the existence of a rainbow: when sunlight hits water droplets, the rays refract and break down into different color shades.
Moreover, every object in the Universe actually has no color shade of its own but has a molecular or atomic structure. When the rays of polychromatic light illuminate an object, most of them are absorbed by molecules, but only some wavelengths are reflected from the particles due to their comparable size. The reflected light is thus what the human eye sees: the color of an object.
Reasons for the Blue Sky
The blue color of the sky, which is mainly observed during the day time, is dictated by the phenomena of light waves scattering on solid particles of the atmosphere. The electromagnetic beam of white light coming from the Sun is directed towards the Earths surface, but on this way, there is an obstacle in the form of a gas envelope of the celestial body. As it was mentioned earlier, some wavelengths of the color spectrum pass freely through this obstruction, while some of the beams meet proportional atmospheric molecules. For instance, frozen nanoscopic crystals of water may have a similar size to that of the blue wavelength (about 410-4 nm). As a result of the coincidence of sizes