why is the sky blue?

Answer 1

I think this is about the 134th time this question has been asked here, and I have yet to see a completely satisfactory answer - so here is my attempt to give one:-

There are a number of factors which need to be considered when answering this question - 1. The physics of why a particular wavelength of light reaches your eye. 2. The way in which that light is translated into a colour by your eyes and nervous system. 3. The social aspect.

Here are my answers to each of those parts.

1. When the sun's light hits the earth's atmosphere and moves through it, most of the lower frequencies (longer wavelengths) pass through with little resistance. The higher frequency light (shorter wavelengths) however, is absorbed to a larger extent by the gas molecules. The absorbed light is then radiated in different directions and thus, gets scattered so that whatever direction you look in, some of this higher frequency scattered light reaches your eyes. This is known as "Rayleigh Scattering"

2. The human brain derives color by comparing the responses to light from three types of cone photoreceptors in the eye. These cone cells are sensitive to different frequency (or wavelength) ranges in the visible spectrum. In this case, the cone cells which are more sensitive to higher frequency light become more active than the others, and comparitive responses of the cone cells gets translated into the colour associated with higher frequency light.

3. From the time we are born, we are taught names for our perceptions of different natural phenomena, i.e we are socially conditioned to call something we percieve by a specific name. In this case, the colour blue is what we are socially conditioned to call our brains response to the light that reaches our eyes through Rayleigh Scattering.

Thus, the sky is blue.

Answer 2

Nitrogen gas makes up about 80% of our atmosphere - it is coloured v faint blue - you can't notice it close up but when you see heaps and heaps of it as you do when you look up, it looks blue. Chemists can prove this by looking at the way that nitrogen molecules vibrate, but you can see it too if you put liquid nitrogen up against something white to show up the colour (I've seen it - it's really true!).

btw the sky isn't blue cos it reflects the sea (water's not blue and gasses don't reflect things!) - it's the other way around - the sea is blue because it is reflecting the sky!

Answer 3

the sky is blue because the sunlight gets dispersed by very small particles, the smaller the particles the more blue comes to our planet. Compare the smoke from a cigar that has blue color, once it has been inhaled by the smoker the smoke particles are coated with water and that smoke is grey. Steam are water drops and even bigger. They are white. And thats why the clouds are white.

Answer 4

the sky is blue because of the light from the sun reflecting back the colour of the earths oceans onto the ionisphere and statosfere ,as two thirds of the planet are covered in water, that is why the sky goes black when the sun goes down at night.....

Answer 5

The sky is blue because the visible spectrum of UV light that the sun emits runs through the prism of ozone molecules in the earth's upper atmosphere. The reflected light is bluish in color.

Answer 6

If that's the question then why are grass green, blood red, they all have some scientific way to tell, I am not sure about sky but i do know about blood and grass hehehe blood it's because of chemical substance called hemoglobin which makes it appear red and for grass it's called choloroplast which make it look green.

LOLZ hope i made something clear which you didn't wanted the answer of.

Answer 7

Here comes the blue sky again. This link will definitely give you all sorts of answers. Goodluck in your pursuit of finding why the sky is blue.

http://answers.yahoo.com/search/search_r...

Answer 8

Light shone through oxygen molecules gives a blue tint

Answer 9

On Mars, it's pink.

Answer 10

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