~ Why is the Sky Blue? ~

[Jeanway 0]

I know this little poem isn't the REAL reason but do you know?

 

~ Why the Sky is Blue ~

 

 

I don't suppose you happen to know

Why the sky is blue? It's because the snow

Takes out the white. That leaves it clean

For the trees and grass to take out the green.

Then pears and bananas start to mellow,

And bit by bit they take out the yellow.

The sunsets, of course, take out the red

And pour it into the ocean bed

Or behind the mountains in the west.

You take all that out and the rest

Couldn't be anything else but blue.

Look for yourself. You can see it's true.

[fenriz275 0]

Light is made up of electromagnetic waves.

 

The distance between 2 crests in this wave is called the wavelength.

 

White light contains all the colors of the rainbow.

 

The amount of light scattered for any given colour depends on the wavelength of that colour.

 

All the colors in white light have different wavelengths.

 

Red light has the longest wavelength.

 

The wavelength of blue light is about half that of red light.

 

This difference in wavelength causes blue light to be scattered nearly ten times more than red light. Lord Rayleigh studied this phenomena in detail. It is caused the Tyndall effect or Rayleigh scattering.

 

Lord Rayleigh also calculated that even without smoke and dust in the atmosphere, the oxygen and nitrogen molecules would still cause the sky to appear blue because of scattering.

 

When blue light waves try to go straight through an oxygen and nitrogen molecules, its light is scattered in all directions because of this collision.

 

This scattered blue light is what makes the sky blue.

 

All other colors (with longer wavelengths than blue light) are scattered too.

 

Blue light's short wavelength causes it to be scattered the most.

 

(The shorther the wavelength of the color, the more that color gets scattered by the atmosphere)

 

Actually, violet has the shortest wavelength of all colors. Violet is scattered even more than blue light. However, our eyes are much more sensitive to see blue than violet, therefore we see the sky as blue.

 

Very little visible light is absorbed by the atmosphere.

 

Blue sky: summary

Blue light's short wavelength causes it to get scattered around 10 times more by oxygen and nitrogen molecules than the longer wavelengths (like red) of the other colors visible to us.

 

The blue in the sky we see is scattered blue light.

At one time I knew that, but I had to go look it up for this thread.

 

Just a little more info, if you want.(This internet is actually useful soemtimes. )

 

John William Strutt, 3rd Baron Rayleigh

born Nov. 12, 1842, Langford Grove, Maldon, Essex, Eng.

died June 30, 1919, Terling Place, Witham, Essex

 

English physical scientist who made fundamental discoveries in the fields of acoustics and optics that are basic to the theory of wave propagation in fluids. He received the Nobel Prize for Physics in 1904 for his successful isolation of argon, an inert atmospheric gas.