wy is the sky blue?

Answer 1

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 comparative 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 perceive 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

The sky is blue because the particles in the atmosphere scatter blue light more than red light. The light is refracted in such a way that only blue light is reflected. The reason the sky changes colors at sunset and sunrise is that the sun's light is coming towards us at a much sharper angle, changing the frequency the light is refracted at. For the same reason, the sun appears to be the opposite color of blue, yellow.

Answer 3

The sky isnt always blue. The sky is blue because the spectrum of the particles in reflecting light is toward the blue end meaning the wavelength is shorter.

Answer 4

The color of the sky is blue because of the way our eyes work and the wave length of light that humans see in. Some insects and birds see colors in a whole different way than people do. You could say the sky is only blue to us humans. An alien coming here from another planet might have eyes that are different than ours and might see the daylight sky as pink or green.
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Answer 5

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

The white light from the sun is a mixture of all colours of the rainbow. This was demonstrated by Isaac Newton, who used a prism to separate the different colours and so form a spectrum. The colours of light are distinguished by their different wavelengths. The visible part of the spectrum ranges from red light with a wavelength of about 720 nm, to violet with a wavelength of about 380 nm, with orange, yellow, green, blue and indigo between. The three different types of colour receptors in the retina of the human eye respond most strongly to red, green and blue wavelengths, giving us our colour vision.

Answer 6

Light coming from the sun is what's called "white light" White light contains all the colors of the rainbow. When it enters Earth's atmosphere this light is separated into its individual colors by chemical elements in the atmosphere and scattered across the sky. Nitrogen is the most abundant element in our atmosphere, and that element scatters the color blue across our sky more than the other colors. In space, there is no atmosphere to separate colors from the white light and space looks black.

Answer 7

Light from the sun is composed of ALL colors. As it hits our atmosphere it is refracted by oxygen atoms which bring it into the blue wavelength of the electromagnetic spectrum. We see it as blue - azure if you want to be technical.

Answer 8

Of all the ultraviolet light coming through earth's atmosphere, light blue shows up the easiest. Cool avatar.

Answer 9

Hi. Why does almost everyone who asks this question have trouble typing? That's just the way it is. (Sorry Rayleigh!) http://en.wikipedia.org/wiki/Rayleigh_scattering

Answer 10

Its because of the Ozone. Also due to sunlight reflecting the ocean surface.