why is the sky blue?

Answer 1

Here is something interesting to think about: 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

The color of the sky is a result of diffuse sky radiation.

On a sunny day the Earth sky usually looks as a blue gradient — dark in the zenith, light near the horizon
.
It turns orange and red during sunrise and sunset, and becomes black at night.

Answer 3

Justanotherengine is absolutely correct.

It amazes me how many people think it's a reflection off the sea. How would you explain the deep blue skies of central Australia, more than 500 miles from the sea, with the atmosphere only 60 miles thick? Or even better, central Asia, 1500 miles from the coast?

Answer 4

molecules in the air scatter light waves, "Blue" has the shortest wave length. When the sun sets, the light waves must travel through more of the Earth's atmosphere because of the angle, so longer light wavelengths only get through, thats why sunsets are so pretty with the longer wave lengths such as "Red, orange, and yellow"

Answer 5

Can you imagine if the sky green or yellow? Isn't it disgusting?? So it's blue, make our eyes fresh when we see the sky.

Answer 6

The air chemicals do so, such as Oxygen and Carbon Dioxide, Hydrogen Dioxide, Hydrogen Oxide and Hydrogen Monoxide, etc, Methane, Beryllium oxide (evaporated Beryllium) and Calcium Oxide as as Carbon Oxide, etc. These minerals make up the air and the sun's light illuminates these elements and minerals.
At night the sun can't illuminate it so the chemicals, minerals and elements are invisible.

Answer 7

it is the reflection in the sky off the water

Answer 8

My friend who is down with jaundice asked me same question but he asked why the sky is YELLOW.I am now totally confused because I am new to this country .

Answer 9

Because it absorbs all other colours except blue..

Answer 10

Combination of light angles.