why is the sky blue?

Answer 1

Just because.. duh

Answer 2

another similar question, so here's the answer:

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 colors because the blue light has been scattered out and away from the line of sight.

http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html

In the evening, the sky sometimes looks orange or red because of air pollution. Dust and other floating particles in the air act as a filter on the sunlight. When the sun is low the air layer is thicker and the light is more filtered, so it looks yellow, orange and finally red.

http://www.sciencemadesimple.com/sky_blue.html



In detail...: Light of a particular color is determined by its frequency. The higher the frequency, the more blue it appears.

Sunlight is made up of many frequencies that when mixed together produce white light. You may have seen a rainbow or the prism experiment where the white light is split up into several colors (frequencies).

The earth's atmosphere is filled with minute dust particles that act like a filter, scattering the light rays. The rays of light with the longer wavelengths, such as reds and yellows, tend to travel more easily through the atmosphere, while the rays with the shorter wavelengths, like blues and indigos, tend to be dispersed more easily. These more easily dispersed shorter light rays are what give the sky its blue color.

Incidentally, red skies at sunrise and sunset are caused by the same phenomenon. When the light hits the Earth at an angle it has more of the atmosphere to go through; this increases the filtering effect and that is why you see a red sky.

Answer 3

This question has been asked over 5000 times, and I've prepared a simple answer, without too much science:

The correct answer is that the blue light is scattered by the air molecules in the atmosphere (referred to as Rayleigh scattering). The blue wavelength is scattered more, because the scatteing effect increases with the inverse of the fourth power of the incident wavelength.
OK, but I've known science graduates who don't understand what this means.
Here's my attempt at an answer without too much physics:

I think most people know that sunlight is made up of light of several different wavelengths, and can be split up into the colours of the rainbow. Blue light has the shorter wavelength, and red the longest wavelength.

When sunlight hits the molecules in the atmosphere, the light strikes the molecules and is absorbed. The molecules vibrate and and give off, or 're-emit' the light. Because the molecules vibrate in all directions, the light is emitted in all directions (called 'scattering'). The molecules in the air are much smaller than the wavelength of visible light, but because the blue wavelength is shorter and more energetic, it reacts much more with the air molecules than the red and yellow wavelengths; which tend to pass straight through.

Because the blue radiation is re-emitted from the air molecules in all directions, it seems to us looking from the ground that the blue light is coming from everywhere; hence the sky seems blue.

Near sunset, because of the low angle of the sunlight, we see more of the red and yellow wavelendth passing straight through, hence the colours of the setting sun.

BTW: The sky isn't blue because of a reflection of the sea; its the other way round, although the blue colour of the sea is mostly caused by the water molecules scattering the blue light, in a similar way. This effect is even stronger with ice; which results in the intense blue colour we see if we look down a crevasse in a glacier, or down a hole in the snow made by a ski stock..

For a complete, scientific explqanation, look up 'blue sky' in Wikipedia.

Answer 4

As my teacher told me last year The sky is not blue but a mixture of gray

Answer 5

Ppl are soo annoying...heres the real answer...

Our earth is made up of 77 bercent water, and 33 perxcent land. Therefore and obviously, there is more water. What the blueness is, is a reflection of the water in our atmosphere.

Hope i could help =]

Answer 6

havent you seen that girlscout commerical?

colors are diffused by different wavelengths.
since blue is the shortest wavelength, its diffused up to ten times more.

Answer 7

Because it matches the green of grass. Wouldn't your eyes hurt if the grass was bright red?

Answer 8

Because of the reflection of the oceans.

Answer 9

Blue light travels further than red light. ?

Answer 10

You are SOOOO original.

This question should be banned.

http://answers.yahoo.com/search/search_result;_ylt=AnmvufhmUPm_Nd0UkwyXnysDxgt.;_ylv=3?p=why+is+the+sky+blue

5,587 hits.

Answer 11

it's the reflection from the water.