Since the sky is blue, why doesn't everything outside have a blue tinge?

Question

Shouldn't a white sheet of paper taken outside look blue with all of that blue light out there?

Answer 1

Most of your answers here are completely wide of the mark, and none seems to actually know why the sky is blue.

There are two things at work here.

The first is that not all of the light reaching you paper comes from the sky. Some comes directly from the sun, or bounces off other things. With no atmosphere the sky would be black, but it would still be light in the middle of the day. Sunlight actually peaks in the green part of the spectrum.

The sky is blue because ALL of the light coming from it is scattered (its called Rayleigh scattering). Particles scatter light more if the frequency is higher, so blue light scatters more than red and hence the light from the sky in the day is mostly blue. By contrast, at sunset when you are looking directly through the sky at the sun red light is scattered less and so the sunset is red.

The second issue is to do with the way your eyes work. Your eyes do NOT see the frequency of light, or even judge colour from the power spectrum of frequencies. If they did the paper would be deep red in an artificially lit room (incandescent light is mostly red) and green under fluorescent tubes. But it stays white.

In fact your eyes are astonishingly good at deriving colour from comparison across the field of view, and do a very good job of maintaining colour constancy. So much so that when Disney licensed technicolor and became the only movie producer that could produce three colour cartoons, Warner developed a two colour process that only used blue and green. However, the eye constructs the missing red from the information that is available and sees a full colour image.

Answer 2

Good question, a nice twist on the classic "why is the sky blue?"

If you arrange it so that only the light from the blue sky falls on the white paper, the paper will look the same color as the sky. Cameras do this to film, but it's hard to do while looking at the paper, since light comes from all directions, not just the sky.

For example, direct sunlight is a bit yellowish, light from grass and trees and buildings and cars and the person looking at the white paper are all different from the blue sky. It generally all averages out to make an average white. But if you set up a carefully shaded and shielded demonstration, you can successfully make it look blue.

Answer 3

As I've always understood it, perhaps incorrectly, the sky may look blue but that's a combination of filtered light through the stratoshpere from the Sun and a larger dose of reflecting the predominant colour of the earth (i.e.: blue planet) which is why it always seems more vibrant in Mediterranean and island climes - than, say, Siberia.

That may not be entirely accurate, but it seems to make some sense to me.

One other thought - if, for argument's sake, the sky and air was genuinely blue. I'm fairly certain that the sheet of paper would still seem white, as we conditon our perception of colour to the prevailing surrounds. The only example I can think of right now is if you've ever been skiing and worn yellow or orange lensed sunglasses. As soon as you put them on you notice the different colour effect, but your brain sort of recalibrates to compensate - so the snow is still white and so on.

Interesting question though, and there must be someone with a more definitive response.

Answer 4

What we see isn't light.
What reflects in our eyes is light

The sky is blue coz during the daytime outta the seven colours VIBGYOR, the colour blue is in the greatest proportion and the whole sky gets illuminatid due to reflections f the light on the molecules of air and the dust particles

so the sky appears blue..

so the conclusion:
there is no blue light
light is what reflects in our eyes

Answer 5

Our sky is blue because of the interaction of ultra violet radiation from the sun with the nitrogen in our atmosphere. The oceans are not blue, that is the color of the light reflected from them. It is just like, ladies, your lips are not red, they are actually blue-green. They appear red because that is the color of light reflected off of them.

Answer 6

actually sky is not blue, it looks like that bcoz of the sun light....
as u can figure it out by the fact that its blue during daytime and black during the night...
everything gets it color and we r able to see its color due to the absorption of the sunlight and reflecting the color among the 7 colors VIBGYOR of the sunlight....
thts y white sheet of paper looks white and red sheet looks red

Answer 7

all light can be measured on the spectrum of colors....


the sky reflects the blue parts of the spectrum...

and a white sheet of paper.. reflects all the light found in the spectrum

and if you had black paper.. that would be seen as the absorption of all light.......in the spectrum...

the grass is green as the green light in the spectrum..... is reflected...

Answer 8

The blue color is water molecules in the atmosphere refracting sunlight. Direct sunlight is slightly towards the yellow end of the spectrum.

Answer 9

It does.