What is the explanation for the fact that the sky be blue? The answer to this question can be given from a physical phenomenon that occurs in the atmosphere called rayleigh scattering. As you know, the solar radiation that warms the Earth is a extremely bright white light, but made up of several other shades of color, each with a specific wavelength. What happens is that when light penetrates the atmosphere, it hits the atoms of nitrogen and oxygen, as well as the other particles that make up the atmosphere, giving rise to the scattering phenomenon.
When passing through a prism, the white light spreads out, revealing the colors that compose it.
As we know, the light is wave which has various lengths. According to the physical phenomenon of scattering, sunlight is scattered in various directions and with various shades of color, each with a specific wavelength. However, the wave that has the length of the blue color is much more defined and efficient than the others. That's why we see the Sun as a bright disk and the rest of the sky all blue, precisely because of the effect that light has on the atoms that make up the air.
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This fact also occurs in the afternoon, when we start to see the sky with a slight touch of red or orange, which is due to the fact that the light travels a greater way to reach our eyes.
By Marco Aurélio da Silva
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
SANTOS, Marco Aurélio da Silva. "Because the sky is blue?"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/por-que-ceu-azul.htm. Accessed on June 27, 2021.
Physics
Optical phenomena are events that are very present in our daily lives resulting from the interaction of light with matter. Among the most important optical phenomena, we can highlight reflection, refraction, absorption, scattering and light interference.
