How come the sky is blue?

Question

I'm always looking up at the beautiful sky wondering why the sky is blue . . . why not green or purple or hot pink.

Answer 1

"The light from the sky is a result of the scattering of sunlight, which results in a light blue color perceived by the human eye. On a sunny day Rayleigh Scattering gives the sky a blue gradient — dark in the zenith, light near the horizon. Light that comes in from overhead encounters an air mass 1/38th of the mass that of a sunbeam coming along a horizon paths. So, fewer particles scatter the zenith sunbeam, and, therefore the light remains a darker blue.

The sky can turn a multitude of colors such as red, orange and yellow (especially near sunset or sunrise) and black at night. Scattering effects also partially polarize light from the sky.

Sky luminance distribution models have been recommended by the International Commission on Illumination (CIE) for the design of daylighting schemes. Recent developments relate to “all sky models” for modelling sky luminance under weather conditions ranging from clear sky to overcast."

That's Wikipedia's answer.  Simply put, scattered light makes it look blue to the human eye.

Answer 2

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  The sky appears blue because when sunlight filters through the oxygen in the atmosphere, the oxygen absorbs all other colors but blue. The reason the sky is not so blue that it is black though, is because only 20% of the atmosphere is oxygen.

The sun light from the sky is a result of the scattering of sunlight, which results in a light blue color perceived by the eye. In day Rayleigh Scattering gives the sky a blue gradient - dark in the zenith, light near the horizon. Light that comes in from overhead encounters an air mass 1/38th of the mass that of a sunbeam coming along a horizon paths. So, fewer particles scatter the zenith sunbeam, and, therefore the light remains a darker blue.

Answer 3

because dats da color i picked....looks nice right? i like :)

Answer 4

When the sunlight passes through the nitrogen particles in the air, it splits up in to the spectrum. Blue has the shortest wavelength, so it scatters more. It's an effect known as Rayleigh Scattering.

Answer 5

Refraction of the sun through oxygen and water molecules or atoms.  Or because God made it that you.  Your choice, either works for me.  Good luck to you.

Answer 6

Because light from the sun is scattering by atoms and molecules in the atmosphere.

Light scattering by particles depends on the relative "sizes" of the photons and the particles.

In the case of visible light, molecules are much smaller than the wavelength of light, so blue light gets scattered much more than red light.

So as light from the sun enters the atmosphere, more blue photons get reflected (not absorbed) by molecules than red photons - but then the blue photons get reflected again and again until they reach us. So the blue light comes from all over, the red light comes almost straight from the sun.

This is also why the sun looks redder at sunrise and sunset - the light's path through the atmosphere is longer when the sun is on the horizon than when it is high in the sky.

Interaction of light with the atmosphere does all sorts of weird and wonderful things that physics can explain:

http://hyperphysics.phy-astr.gsu.edu/Hba...



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