Hacking What makes the sky blue?

[DJ91990]

Hey guys, time for a stupid yet scientific question;

Why is it that the sky is blue during the daytime?

 

[PassiveFist]

The short answer is that atmospheric pressure makes the sky blue. The long answer is complicated and not any more interesting than the short answer. Dramatic pressure changes, such as with major storm systems or high altitudes, can change the color of the sky many colors, from green to white.

As another example, on Mars the sky is deep purple to black during the day due to the very low pressure there.

 

[macgeek417]

...wrong section, but:
The oxygen in the air has an extremely slightly blue tint. When you look through large amounts of it - i.e. miles of air into the sky - the blue tint stands out.
When it is dark out, there is no light shining through the air so it is not blue.

 

[Lily]

The light from the sun appears to be white. That light travels in a straight line until something in its path causes it to reflect, bend or scatter. It appears to be white, but is really made up of all the colours of the rainbow. That light travels in waves. Some waves are short and choppy, other waves are lazy and long. Blue is the shortest of all the light waves. When the white light from the sun hits the Earth's atmosphere, it is scattered. As blue is the shortest light wave, it is scattered more than all the other colours, making the sky appear to be blue.