Answer to Question #38106 in Optics for daisy

Question

why does clear sky look blue?

Answer 1

The sky looks blue for the reason that the air scatters light with a short wavelength much more than long-wave light. Since the blue color is at the short wavelength edge of the visible spectrum, it is dissipated much more in the atmosphere than red. Because of this, if you look at the part of the sky is the sun, we see the blue light (but not purple due to a lower sensitivity of the eye) - the result
of scattering of solar radiation. During dawn and dusk, the light passes tangentially to the earth's surface so that the path traveled by light in the atmosphere becomes much bigger than during the day. Because of this, most of the blue and even green spectrum of the light is lost in the direct sunlight
sue to dispersion, so the clouds and the sky near the horizon, are painted in red tones.