Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why is the evening sky blue?

  1. Jul 13, 2015 #1
    I know the question is generally "Why is the evening sky red/orange?" but actually the evening sky is very rarely red/orange. On most evenings it is blue. Why is it blue? Shouldn't it be red/orangish? Does the location on earth have anything to do with this?
     
  2. jcsd
  3. Jul 13, 2015 #2

    sophiecentaur

    User Avatar
    Science Advisor
    Gold Member

    It depends on which direction you are looking. Looking towards the setting Sun, you will always get at least a hint of orange / red, which is stronger when the atmosphere is full of scattering particles likedust or water droplets / thin clouds. The blue colour can be seen when you look up or away because there is still comparatively more blue light scattered downwards.
    You need to be careful when assessing the colour of the sky (and many other things) because your observational powers are very much affected by context (we are very subjective about these things).
    I always use the terms "reddish" and "bluish", to allow for this. This is one of those topics that are frequently discussed and there is a lot of misinformation flying around about it. Don't believe everything you read and check it all against basic theory. :smile:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Why is the evening sky blue?
  1. Why sky is blue? (Replies: 7)

  2. Why is the sky blue? (Replies: 23)

Loading...