Why Does the Sky Look Blue? Rayleigh Scattering

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The sky appears blue due to Rayleigh scattering, where shorter wavelengths of light, like blue, scatter more than longer wavelengths, such as red. During sunsets, the light travels through a thicker layer of the atmosphere, scattering away blue light and allowing red wavelengths to dominate. This scattering is not due to absorption and re-emission by nitrogen but rather an instantaneous interaction with the polarizable medium of the atmosphere. The blue light that is scattered can still be seen in other locations, contributing to the overall perception of a blue sky. The interaction of photons with nitrogen involves deviations in their paths due to the influence of electrons in the nitrogen molecules.
cragar
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is the sky blue because , blue light has more energy so it gets scattered to our eye, and red light has less energy so it gets scattered away from our eye , and when the sun sets the angle the light enters our atmosphere changes , is this similar to white light entering a prism and that might be why sunsets are red . ,
and when the light goes trough the atmosphere are the photons absorbed by the nitrogen and then re-emitted , if not how do the photons interact with the nitrogen and what causes them to be scattered .
 
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cragar said:
is the sky blue because , blue light has more energy so it gets scattered to our eye, and red light has less energy so it gets scattered away from our eye , and when the sun sets the angle the light enters our atmosphere changes

Both red and blue light get scattered in the same directions, it's just that blue light scatters more than red, so we see the sky as being blue. Sunsets look red because the light from the sun has to pass through more atmosphere, and blue light has mostly been filtered out.

EDIT: I should add that the sky looks blue because of shorter wavelengths being scattered more than longer wavelengths AND the fact that our eyes are much more sensitive to blue than say, violet.

cragar said:
is this similar to white light entering a prism

No, the prism effect is because different wavelengths have different refractive indices, has nothing to do with scattering.

cragar said:
and when the light goes trough the atmosphere are the photons absorbed by the nitrogen and then re-emitted , if not how do the photons interact with the nitrogen and what causes them to be scattered .

Scattering is NOT absorption and re-emission. Absorption and re-emission involves transitions between real energy states that possesses a characteristic lifetime, wheras scattering is more-or-less instantaneous. Scattering occurs as a natural consequence of EM waves interacting with a polarizable medium.

Claude.
 
sweet thanks for the answer .
 
No worries!

Claude.
 
Claude , when you say sunsets look red because the blue light has mostly been filtered out ,do you mean by filtered that the blue light was absorbed.
 
Not absorbed, but instead, scattered. Some of the blue light that is "missing" from the sunset you are looking at, is seen as part of the blue sky by someone else in another location.
 
is blue light scattered more because it has more momentum , When the blue photon enters the atmosphere , you said it scatters because it is interacting with a polarizable medium , what cause the photon to deviate from its path , are the electrons in the nitrogen affecting the electric and magnetic component of the photon ?
 
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