why sky looks blue in colour?

Question

from earth

Answer 1

http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html

http://www.sciencemadesimple.com/sky_blue.html

read

Answer 2

The sky is blue because of the scattered light in the atmosphere. White light has several wavelengths from red to violet and the scattering is inversely related to the wavelength. Blue being shorter than red, is scattered more by the air and hence the sky is blue during the day.

If the atmosphere was something other than the nitrogen + oxygen mixture which we call air (like say carbon dioxide or something else), the color would have been different. In moon and similar smaller celestial bodies with no atmosphere, the sky is space and is black with all the stars perfectly visible through out the day and night.

Similarly in the sunrise and sunset times, the part of the sky closer to the sun appears reddish orange because the sunlight needs to pass through more atmosphere and the blue light gets absorbed and attenuated by scattering. Thus reddish tinge comes. The other part of the sky continues to be blue at that time.

Answer 3

The atmosphere scatters the blue light of the sun and therefore makes the sky blue. See link below for more info.

Answer 4

because of the dust particles that are reflected by light up in the sky which causes normally blue shades.