why is the sky blue?

Answer 1

Because is the reflection of the sea.

Answer 2

You know, much as this is seen as a juvenile and kid-type question, the fact of the matter is that nobody, scientists included, really know for sure.

What we DO know, however, is that the answer provided to most children in the interim (that its the reflection of the ocean and whatnot, or some variation) is not true at all. This is disproven very logically and easily: the earth isnt all ocean, and so the sky shouldnt be all blue either... and people in the middle of asia, where there is no ocean for thousands of miles, certainly do not see a green, gray, or tan sky.

The earth, like the moon, reflects sunlight... and like trying to look out of a subway window, some of that light is internally reflected via the atmosphere (i.e. it comes from the sun, reflects off the earths surface, hits the atmosphere and returns to your eyes).One of the current theories is that the atmosphere and its chemical makeup (nitrogen, oxygen, carbon dioxide, etc. as well as dust and other particulate matter) bends that reflected light in such a way that when it bounces back, the wavelength of said light has been changed to a blue spectrum.

It may also have to do with the curvature of the earths atmosphere. Like when you shine a beam of white light into a prism, the triangular configuration slows the wavelengths and separates them into their visible colors. The curvature of the atmosphere may also have an effect. It would be hard to explain without a diagram, but it could be that the curvature is just enough that all other colors are refracted away from the earth and away from your eyes.

EDIT: to refute some of the other answers:

Blue has a shorter wavelength: Actually blue is in the middle of the wavelength spectrum. Red has the longest, deep purples have the shortest.

Water droplets: Though there is water everywhere there is any amount of humidity, the sky is certainly blue on bright and sunny days. Also, if water was involved in the color, logic would suggest that there would be a difference in sky color between humid and dry days... and there is not.

God made it that way: This needs no explaining... -snicker-

Answer 3

The reflection of the ocean? That's the dumbest thing I've ever heard. Pick up some of that ocean water in a glass and look at it - is it blue? No - it's clear! The ocean appears blue because it is reflecting the sky, not vice versa. The sky is blue because the white light from the sun gets diffused in the atmosphere. Most of the longer wavelength light (e.g. red, orange) passes straight through, but the shorter wavelength light (blue) is absorbed by gas molecules in the air. It is then radiated across the sky in all directions, which is why the sky appears blue.

Answer 4

Rayleigh scattering of light is proportional to the fourth power of the frequency. Taking a typical blue wavelength to be 450 nm and a typical red wavelenght to be 630 nm, the ration of scattering is (630/450)^4 (remember freq = c/wavelength). Hence proportionately more blue photons than red photons are scattered by the atmosphere toward an observer on the ground and the sky appears blue.

Answer 5

I hope u heard abt VIBGYOR.So MORNING THE SKY WILL BE IN BLUE COLOR AND U CAN OBSERVE THE DIFFERENCE IN THE EVENING AT AROUND 5:30 T 6:00.THE SKY CHANGES TO RED.

Answer 6

If I remember correctly, molecules of our atmosphere (composing of mixtures of gases) have different colors. When the light (the sun’s rays) hits the molecules it sends out colors like the rainbow. Remember the science experiment Prism? It’s similar to that. It’s just that blue dominates the spread of the colors. That’s why in space, there’s no blue color because there is no air molecules or an atmosphere for the light to change to these colors; or when its dark, there is no light to react with the atmosphere.

Answer 7

Because sky has no colour and blue colour has the shortest wavelength. This colour after refection reaches first to us and the sky seems us blue

Answer 8

Because the blue color light has a much shorter wavelength than the other colors and it gets dispersed easily by the atmospheric particles.

Answer 9

the atmosphere refracts light different from the air you breathe at sea level. because blue is the fastest- it is the one you see. and by light refacting, i mean the sunlight is refracted.

Answer 10

water light refex off the water on the clouds