Why is the sky blue?

Answer 1

The sky is blue due to an atmosphetic effect called Rayleigh scattering - certainly not because its reflecting the ocean which people sometimes say! Rayleigh scattering involves the scattering of light by molecules smaller than the wavelength of light. It has a smaller effect on colours with longer wavelengths and that is why the sky is blue - and also in fact why the sun is yellow - if you added up all the blue tint in the sky and focused it in the area of sun you would get its actual colour of bright white, which is what you’d see in space.

Physicists used to say that Rayleigh diffraction was responsible for the reddish tint in sunrise and sunset because the light had to travel through more atmosphere to reach us however this is currently disputed and there is another optical theorem at work called 'Lorenz-Mie theory'.

http://science.howstuffworks.com/question39.htm
http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html
http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html
http://www.exo.net/~pauld/physics/why_is_sky_blue.html

Kind regards.

Answer 2

Most incoming solar radiation is at visible green wavelengths (this is why our eyes are most sensative to green light). However, Earth's atmospheric gasses scatter incoming solar radiation, more so in the blue wavelength region than in longer wavelngths (green or red), hence blue sky.
When the sun is low in the sky, the light has a thicker section of atmosphere to penetrate, so more red light is scattered, this is why sunrises and sunsets cause redder colors.

Answer 3

because of the tyndall effect. This causes blue light to be reflected down to the earth's surface which makes the sky appear blue.

Answer 4

ozone - but for realz it's little fairies holding their breath. there's lots of them, so when one has to breathe another takes over. and since it's so far away it looks like the whole sky is blue, rather than just a bunch of little blue faces.

Answer 5

it isnt blue it is white the reason it feels blue is beacuase the sun is pointing down at the sky which is white and then makes it blue

Answer 6

Well I had thought it was because of scattering by dust in the atmosphere, but the web site below says that Einstein proved that the atmosphere itself provided this effect.

Answer 7

Blue is just a word, it doesnt relate to it. Hhe no its the ozone layer.

Answer 8

Because blue is cool.

Answer 9

Because of global warming, yer right, try asking an original question next time.

Answer 10

Is this not one of the most asked questions on YA?