What makes the sky blue?

Answer 1

It's due to a phenomenon called Rayleigh scattering. When light encounters particles much smaller than the wavelength of light, the light scatters. Atmospheric gas is an enormous resevoir of such particles. Short wavelengths scatter the most effectively, and blue has a short wavelength, so the blue light scatters and appears to fill the sky. Note that violet has a shorter wavelength than blue, but the human eye is not very good at seeing violet, so blue appears to dominate instead.

Answer 2

I can never remember this, probably because I can't understand it or it doesn't convince me. I understand the planet looks blue from outside. Is it something to do with the atmosphere? because of the nitrogen or oxygen? The clouds, water vapour, look white, it's something in the air that looks blue in sunlight.
The other planets look different. They don't look blue. Presumably their sky isn't blue either? Am I confusing two different things?

So, its to do with the scattering of the sunlight in the atmosphere. But why blue? why is mars sky reddish? They say because of dust and iron molecules, I get that. But what is the actual substance(s) in our atmosphere that make(s) it blue here? I can't find that anywhere.

Answer 3

David K93 is absolutely correct. It's also why the sky can appear red late in the day, as light has further to travel across the sky rather than from directly overhead.

Answer 4

its blue because it is blue, other wise it would be green and you would be going why is the sky green, accept it and move on... if we question everything like this we wouldn't have survived as human will be caught worrying about too much! Ha, its blue lets get over it, I'm sure 'blue' is just our perception.

Answer 5

Are you crazy?

Sky isn't blue. Sky has no color. It appears the inhabitants of earth as blue.
As you ask, what makes the sky blue, the direct answer to it is "REFLECTION OF WATER makes it appear as blue". But Why? Because our earth contains 72% of water bodies. Of it most of water is either in oceans or seas. As you know oceans and seas contains blue algae the most, so the water bodies appear blue. And sky just reflects it. But Where is the reflecting surface? It is nothing but the ozone layer in the atmosphere. If we see sky going above ozone layer, it will surely appear dark. The ozone layer reflects due to an atmospheric effect most probably, "Total Internal Reflection".



ADVISE: Please ask the question perfectly. You asked "What makes the sky blue?" which denotes us that colour of sky is blue. Please don't mind it was just an advise from your friend.
Forgive me, if i hurt you....Thanks.

Answer 6

Sky is blue because of all the water in it (as DavidK93 so rightly explained). You don't realise how blue water actually is, until you compare it with something that's really colourless, such as deuterium oxide (water where the hydrogen is replaced by its heavy isotope, deuterium). Try it and see!

Answer 7

It is because of the blue spectrum in the air is exposed with the sun and reflects the most.

Answer 8

Just type "Why is the sky blue" in "Search for questions" and you'll get about 58 answers

Answer 9

I believe it's because blue light waves are the longest light waves on the color spectrum so it bounces around the most.

Answer 10

Allah's giant blue paintbrush.