To explain why the color of the sky is blue, it is necessary to scientifically conceptualize what is meant by “color” and what is meant by “sky.” The color of a material object, surface, or substance is a particular wavelength of the visible light reflected from it. The wavelength depends on the characteristics of the substance, both psychical and chemical. The sky is not a material object, i.e. there is not a dome made of a particular material that covers the earth. Rather, the sky is a combination of atmospheric layers. The physical characteristics of the atmosphere’s content gradually change depending on the distance from the earth’s surface (Locke & Ball, 2013). The atmosphere is dense enough to accumulate light, preventing us from seeing the stars during the day.
However, the color does not only depend on the characteristics of the substances, but also on the way the light travels. Naturally, the light travels along straight lines, but when something is on its way, one of the three things can happen to change the trajectory of its propagation: it can be reflected, bent, or scattered (Why is the sky blue? 2015). Molecules in the atmosphere scatter the light traveling from the sun through them.
Since blue is the part of the spectrum that is scattered more than other colors due to its shorter and smaller waves, the light we see during the day appears to be blue. However, the sky is not always blue: yellow, red, orange, and violet shades can also be found in it at times. The reason is that light can be scattered differently depending on the direction, angle, cloudiness, and the presence of particular gases and particles in the atmosphere.
References
Locke, J. A., & Ball, D. W. (2013). Why is the sky blue? Spectroscopy, 28(1), 12.
Why is the sky blue? (2015). Web.