Looking up at the sky, when the sky is clear, we can see the blue sky. When the storm comes, we can see the sky with dark clouds. The blue sky always gives people a good mood. Many people have doubts in their hearts: why is the sky blue? Here are the reasons why the sky is blue. Welcome to read.
Why is the sky blue?
The color of the sky is a natural phenomenon. On sunny days, the sky is blue and sometimes turns white, especially on the horizon. Different scientists have many theories about the phenomenon, but one such myth has this explanation: the sky is blue, just as the sun reflects the blue from the ocean. This explanation is incorrect, because the same phenomenon of absorbing light in the atmosphere also occurs in water, because longer light waves absorb deeper than shorter blue light.
The main reason why the sky is blue
The most common theory to explain that the sky is blue is the scattering of light by the atmosphere, which is composed of gases and other particles that collide with light particles and disperse them in different directions and intensities.
Light is a spectrum composed of seven colors with different wavelengths, including red, orange, yellow, green, blue, indigo and purple. Their particles are unevenly distributed. Blue light travels at shorter wavelengths and scatters more than other colors as sunlight passes through the air. Compared with red, blue also has higher frequency and more scattering.
This scattering and re scattering produces the blue effect of the sky, and the light propagates in a straight line in all directions. In these movements, it collides with gas particles and other substances in the atmosphere, absorbs light and emits a color similar to the absorbed light.
The change of sky color
Early in the morning or at sunset, the sky appears white or red. The white of the sky is the result of blue light scattering when atmospheric particles move in the air. Scattering makes the blue light more dispersed, making it look paler from a distance.
As the sun falls in the sky, light passes through more air and even scatters longer light waves, making the red light waves more visible, because the blue light waves have been more dispersed, because they go farther before reaching the eyes.
Put forward the sky blue theory
John Tyndall, a scientist in the 19th century, was the first person to put forward the sky blue theory. Lord Riley elaborated Tyndall's theory of atmospheric scattered light. Rayleigh did more research on light and finally came to the conclusion that blue light scattered more than red light. He estimated that blue light was 10 times more dispersed than red. Previously, scientists believed that dust and water particles in the atmosphere contributed to the absorption and scattering of light. These theories are somewhat incomplete because the sky changes color with the change of dust and water in the atmosphere.
Biology
The color of the sky is also associated with the receptors in our eyes. These receptors have different sensitivity to the trigger factors of various colors, and the eyes have different perception of the color of wavelength. It is well known that blue receptors are more sensitive than red and green receptors, so we are more likely to perceive blue light particles scattered from sunlight.