This morning again a beautiful red sky. But why a red sky? This because of a phenomenon called Rayleigh Scattering. When light travels through a medium with particles smaller (eg. moisture) than the wavelength of light then light will be scattered. The intensity of the scattered light is also dependant of the wavelength (～𝛌-4). For that with blue light having a 2x shorter wavelenght then red light, this means blue light is 16x more scattered then red light. That's the reason why we have a blue sky and not a red... blue is more scattered with having more chance that blue light will hit our eyes.
So now, why a red morning. Ah... this is because in the morning/evening, when the sun is low at the sky, light travels much longer then during the day through the atmosphere. The distacnce can be as even 12x longer then during daytime. So the chance that blue light is fully scattered is very likely and only the red light is available to reach our eyes (so no blue light is left :) )
