• Question: why is the sky blue

    Asked by 9hansb to Antonia, Douglas, Hugh, Matt, Tom on 24 Jun 2010 in Categories: . This question was also asked by 9hardk, 9tunsc, 9lancl, 9adamd, tashaadams, kirstyloo, megannedwardss, jadeebyrnee.
    • Photo: Matthew Hurley

      Matthew Hurley answered on 13 Jun 2010:

      I think that if we didn’t have an atmosphere the sky would have no colour (black). It’s all the stuff in the atmosphere (ozone etc.) that along with the light of the sun makes the sky blue (or orange at sunset).

    • Photo: Douglas Blane

      Douglas Blane answered on 24 Jun 2010:

      Light from the sun has every colour in it. You can see that with a rainbow, when raindrops split the sunlight into its separate colours.

      To reach our eyes sunlight has to pass through the air in the atmosphere. This doesn’t do a lot to the red, green and yellow light in sunlight. But it does to the blue.

      It scatters it. What does that mean? Well just what it says – the blue light bounces off the particles of air. This happens again and again with the blue light bouncing all over the sky.

      So in every direction you look on a sunny day there’ll be lots of blue light hitting your eye.

      This is also why the sun looks yellowish. You’re getting the other colours minus the blue straight into your eye. From space the sky is black and the sun is white.

      If you want to find out more, do a wee search on “Rayleigh Scattering”.