Why does the sky appear blue when we look at it?

(N/A) The intensity of scattered light is inversely proportional to the fourth power of its wavelength,a phenomenon known as Rayleigh scattering.
In a clear sky,the blue color predominates because blue light has a shorter wavelength compared to red light,causing it to be scattered much more strongly by atmospheric molecules.
Although violet light has an even shorter wavelength and is scattered more intensely than blue light,our eyes are significantly more sensitive to blue light than to violet light.
Consequently,the sky appears blue to human observers.