> the sky is blue because air is blue. Things have color because they scatter/reflect/refract/absorb/emit differently for different colors of light. Air looks

> the sky is blue because air is blue. Things have color because they scatter/reflect/refract/absorb/emit differently for different colors of light. Air looks blue because it scatters blue light more than other colors. The blue components of sunlight reach you from all parts of the sky, while the non-blue components reach you mostly from the direction of the sun. At sunset, sunlight from the direction of the sun passes through much more atmosphere than during the day and most of its blue light scatters away, leaving red and yellow. [0] If air didn't scatter light, the sky would be black like it is on the moon. Air is a gas. Gasses do not reflect light. Air refracts sunlight and makes the sun appear flattened at the horizon [1]. Air absorbs most non-visible colors (UV and IR) [2]. Animals evolved eyes to see only the colors of available light. During aurora, the air emits green light. [0] https://en.wikipedia.org/wiki/Rayleigh_scattering https://en.wikipedia.org/wiki/Rayleigh_scattering [1] https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Refractive_index https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Refractive... [2] http://funnel.sfsu.edu/courses/metr104/F13/summaries/AbsorptionSpectra_Atmosphere.pdf http://funnel.sfsu.edu/courses/metr104/F13/summaries/Absorpt...