# Why does the sky is blue?

#### clarityx

Please, answer the question, Why does the sky is blue?

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#### zoobyshoe

Because: the wind is high. It blows my mind.

#### Bob S

Look up Rayleigh scattering on the web: http://en.wikipedia.org/wiki/Rayleigh_scattering
I like the derivation and discussion in Slater and Frank "Electromagnetism" Chapter XII better than in Jackson "Classical Electrodynamics"

#### FredGarvin

Science Advisor
Because if it were green, we wouldn't know where to stop mowing.

#### Danger

Gold Member
Because if it were green, we wouldn't know where to stop mowing.
:rofl:

#### mgb_phys

Science Advisor
Homework Helper
Why does the sky is blue?
Cos raindrops keep falling from it's head.....

#### LennoxLewis

In short: the color we see is scattered light from the sun. However, the scattering process of air with light depends inversely with a fourth power on the wavelength, meaning that blue light (short wavelength) is way more likely to scatter than red light (long wavelength).

However, if a very long distance is travelled, longer wavelength photons will scatter as well, which you can see during a sunset. In case of a sunset, the sunlight "hoovers" over the surface of the earth for a long distance until it reaches your eyes; draw the earth as a circle and you will see why.

#### GetPhysical

Not sure what youre asking. Do you mean "Why is the sky Blue?" I dont think the sky does blue. either way its what lennox said. The scattering of light. Thats all it is.

#### Phrak

Because if it were green, we wouldn't know where to stop mowing.
When does the grass is stopped mowing?

#### zoobyshoe

When does the grass is stopped mowing?
Think: why does the grass is mowed? The grass does is mowed to know when to stop.

#### cragar

why is the sky blue ? Because god made it that way. is as good a reason as any .
the question should be how is the sky blue. basically what lennox said , it was explained to me this way its blue beacuse when the light hits the nitrogen molecules
it absorbs some of the light and blue is a higher energy wavelenght therefore blue light is scattered. sunsets are red becsue the angle of refraction is different and the light is traveling further through the air there fore red light is scattered.

#### HallsofIvy

Science Advisor
Not sure what youre asking. Do you mean "Why is the sky Blue?" I dont think the sky does blue. either way its what lennox said. The scattering of light. Thats all it is.
When does the grass is stopped mowing?
Think: why does the grass is mowed? The grass does is mowed to know when to stop.
Oh, stop! Many of the posters on this board had to learn English as a second language. How would you like to have to phrase question in Holoholo?

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