Why Is The Sky Blue?

Why is the Sky blue: Science, Religion, Crazy.....?

• Why is the Sky Blue? 1.Science: The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. Since you see the blue light from everywhere overhead, the sky looks blue. 2. Religion: Cause God said so. 3. People in straight jacks might believe this: Its all part of an alien cover up. Its like those disk in the cartoon Chicken Little that copied any thing behind it. The purpose for this is so the aliens can observe us, while also giving us a false sense of security that we are alone in the universe. That doesn't really explain the blue color but what do you expect from crazy people.

• Answer:

  Because light from the sun is scattering by atoms and molecules in the atmosphere. Light scattering by particles depends on the relative "sizes" of the photons and the particles. In the case of visible light, molecules are much smaller than the wavelength of light, so blue light gets scattered much more than red light. So as light from the sun enters the atmosphere, more blue photons get reflected (not absorbed) by molecules than red photons - but then the blue photons get reflected again and again until they reach us. So the blue light comes from all over, the red light comes almost straight from the sun. This is also why the sun looks redder at sunrise and sunset - the light's path through the atmosphere is longer when the sun is on the horizon than when it is high in the sky. Interaction of light with the atmosphere does all sorts of weird and wonderful things that physics can explain: http://hyperphysics.phy-astr.gsu.edu/Hbase/atmos/atmoscon.html#c1 However, if you really feel the need to invoke God - then you can argue that He/She/It set up the laws of physics that dictate the scattering effects. As for crazy people - are you sure they see the sky as Blue?