Why is the sky blue ?

Answer 1

Prepare to be dazzled:

When you look at the sky at night, it is black, with the stars and the moon forming points of light on that black background. So why is it that, during the day, the sky does not remain black with the sun acting as another point of light? Why does the daytime sky turn a bright blue and the stars disappear?

The first thing to recognize is that the sun is an extremely bright source of light -- much brighter than the moon. The second thing to recognize is that the atoms of nitrogen and oxygen in the atmosphere have an effect on the sunlight that passes through them.

There is a physical phenomenon called Rayleigh scattering that causes light to scatter when it passes through particles that have a diameter one-tenth that of the wavelength (color) of the light. Sunlight is made up of all different colors of light, but because of the elements in the atmosphere the color blue is scattered much more efficiently than the other colors.

So when you look at the sky on a clear day, you can see the sun as a bright disk. The blueness you see everywhere else is all of the atoms in the atmosphere scattering blue light toward you. (Because red light, yellow light, green light and the other colors aren't scattered nearly as well, you see the sky as blue.)

Answer 2

Short answer - it's not. It just LOOKS blue.

For example, take the sun. If you look straight at the sun you'll see pretty much white - most of the light pretty much goes straight through.

But if you look off to one side of the sun, you will see the light that was heading for a different spot, but which then deflected in your direction. It is easier to deflect short (blue) wavelengths than long (red) ones, so most of the time the sky looks blue.

You'll note that when the sun is low on the horizon (during sunrise and sunset) it will often look reddish... now that the sunlight is passing through more of the air, almost everything BUT the red is deflected. You can see where the light is deflected to after the sun goes down - for a while, you can't see the sun but there's still light to see by... all that deflected light!

If you need more proof, think of this - if the sky were really blue, then almost everything you saw through it would be bluish. All the stars would be blue. All the clouds would be blue, and all the snow on the mountain-tops would be blue. In fact, none of these things are always blue... so any blueness you see is probably not a result of the sky itself.

Answer 3

the sky is blue from the sun rays hitting the water a bouncing back into the atmosphere.which makes the sky blue

Answer 4

A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colours because the blue light has been scattered out and away from the line of sight.

Answer 5

It's called the atmosphere make the sky look blue.

Answer 6

because of the ultraviolet light that reflects of the sun light maybe if you payed attention in your chemistry class

Answer 7

it apperars blue because of the relecton of sunlight in our atmosphere

Answer 8

For the same reason 500,000,000,000,000 other people have asked this question here.

Answer 9

go to the weather channel.com.

Answer 10

Because that's the way God wanted it.