what makes the sky blue?

Answer 1

The sky appears blue to us on a clear day, because the atoms of nitrogen and oxygen in the atmosphere separate the suns white light into its many colours, and scatter them throughout the atmosphere.The wavelength of the blue light scatters better than the rest, predominates over the other colours in the light spectrum, and makes the sky appear blue to us.The scientific name for this phenomenon is the Tyndall effect, more commonly known as Rayleigh scattering.

This phenomenon describes the way in which light physically scatters when it passes through particles in the earths atmosphere that are 1/10th in diameter of the color of the light. The light spectrum ranges in wavelength from red to violet, and, since the wavelength of the blue light passes through the particles with greater ease than the wavelengths of the other colors of light, the sky appear blue to the naked eye.

The human eye has three types of light receptors, known as cones, located in the retina. The cones are either considered to be red, or blue, or green, based upon their strong response to light at these wavelengths. As light stimulates these receptors, our vision translates the signals into the colors we see.

When gazing at the sky, the red cones respond to the small amounts of red light scattered, and even less strongly to the orange and yellow wavelengths. Although green cones respond to yellow, their response to scattered green and green-blue wavelengths is stronger. Finally, colors near the strongly scattered blue wavelengths stimulate the blue receptors.

In short, the skylight stimulates the red and green cones almost equally, while stimulating the blue cones more strongly. For these reasons, our vision naturally adjusts as clearly as possible to separate colors.

Answer 2

This gets asked loads and answered, usually, badly. Rayleigh scattering often gets mentioned. What does that tell you ? You might learn two new words "Rayleigh" and "scattering" but what else ? Does it explain to you why different coloured light is scattered differently ? Thats what the "blue sky" question is really asking.

If you want to know what really happens .....

Forget the atmosphere for a moment, just imagine a single electron and a red photon (which has little energy) and a blue photon (which has a lot).
The blue photon has nearly enough energy to lift the electron to a higher energy state, but it doesn't have quite enough so it borrows the extra energy from nothing at all (really, energy is borrowed from nothing !!!). But, Mother natures rule for borrowing energy is "the more you borrow the sooner you have to give it back". So now we have an electron in a high energy state due to the energy from the blue photon and the borrowed energy. Because only a little bit of energy was borrowed (remember the rule) it can stay in this state for quite a long time before mother nature asks for her energy back. When that happens the blue photon is "kicked back out" of the electron.
The key point is that the electron is part of an atom (say a Nitrogen atom in the atmosphere) and that atom is spinning so it can turn quite a long way round in the time between when the blue photon was absorbed and emitted. The practical upshot of which is that the blue photon approaches the atom from one direction but departs in a very different direction or is "scattered". So all blue light is scattered from all Nitrogen atoms in the atmosphere all around so the sky appears blue. Voila !

A red photon (less energy) to boost an electron to a higher level has to borrow a lot of energy and so has to pay it back sooner. That means the atom won't have turned very far before the red photon is fired out again. So its fired out in pretty much the same direction as it arrived.

Its a bit like jumping on a a merry-go-round. If you stay on for a few seconds, when jump off you'll be travelling in a completely different direction. If you jump on then straight off you'll be travelling in pretty much the same direction as when you jumped on.

Answer 3

The sky is blue because the molecules of air scatter some of the blue light, while allowing the other colors of light to pass through. Why blue? Because the size of the molecules of air are close to the wavelength of blue light...about 0.0004 millimeters in diameter.

Answer 4

The sunlight reflecting off of the different gas (nitrogen, oxygen, etc...) particles in the atmosphere. It appears to change in the early morning/late evening because the rays hit higher in the atmosphere, where the composition of the air is at a different mixture.

Answer 5

atmosphere contains a lot of pollutants and dust particles .the sun emits light and the spectrum is created .but as light gets scattered it blends and forms blue

Answer 6

God created the world and everything in it. He made the sky and he did it all for us...isnt it wonderful?

Answer 7

I thought is was the reflection of the water...

Answer 8

GOD DID THIS, THRU HIS CREATION. DIDN' HE DO A GREAT JOB.