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Color of sky based on atmosphere density

  1. Oct 18, 2015 #1
    If the atmosphere was thiner would the sky be violet?, and if it was thicker would it be red?
    Last edited by a moderator: Oct 22, 2015
  2. jcsd
  3. Oct 19, 2015 #2


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    For a better understanding of the color of our sky google "why does the sky look blue".
  4. Oct 19, 2015 #3
    The answer to your question is simple enough that i'm going to let you think about this: The reason our atmosphere is blue is because the light is refracted from the air and the blue part of light's spectrum is what reaches our eyes. As the sun sets, the light is refracted in a different way causing other colors of the spectrum to reach our eyes.
    Venus's atmosphere is denser than our own, and it turned out to be yellow-ish. Based on that information I believe you can now answer your question.
  5. Oct 19, 2015 #4


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    "Venus appears to be a yellowish color, which is caused by sulfuric acid in the thick atmosphere of the planet."

    While there is an increase in reflectivity with pressure in air; I have found the above reference quote that brings into question the actual effect of the density of Venus' atmosphere upon it its color; but, I have not been able to find any other references that directly speak to the source of the color.
  6. Oct 19, 2015 #5
    The majority of the yellow comes from the abundance of sulfur and sulfur dioxide. I was just picking Venus because I know it has a denser atmosphere. I didn't fully take the composition of the atmosphere into consideration. I apologize for that.
  7. Oct 19, 2015 #6
    This is nonsense. Go to Wikipedia and look up 'Rayleigh scattering'
  8. Oct 21, 2015 #7
    I wouldn't use Wikipedia. It is able to be edited by anyone. If you don't believe me, go on Wikipedia and then click the edit on a page. That's how I know Wikipedia is not a reliable source.
  9. Oct 21, 2015 #8


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    Nonetheless refraction is an incorrect explanation and Rayleigh scattering is a correct one.
  10. Oct 21, 2015 #9


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    @CrackerMcGinger you need to go do a bit more reading before posting incorrect info :smile:

  11. Oct 22, 2015 #10
    I know this is constructive criticism, but can we please get back to the main reason of this thread? I know I answered incorrectly, and I do apologize for that, but we could be helping the starter by telling him/her what to look up (not with Wikipedia) while explaining why I'm wrong, instead of just telling me it's wrong and not giving an explanation why. This would benefit not only me, but the starter as well.
  12. Oct 22, 2015 #11


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    While Wikipedia may not be utterly reliable, it is usually quite good and does provide references. You can Google for Raman scattering and Rayleigh scattering.

    Refraction as an explanation does not appear to pass the "sniff test". The refractive index of air is small and the variation of that refractive index with respect to frequency is even smaller. The primary effect of refraction would be to deflect an image through a small arc. Yet when looking at the sun, moon and stars, we do not ordinarily notice any prismatic fringes at the edges of the image. We do notice "twinkling" of stars but, as expected, that is a small deflection. The blue sky involves deflections of up to nearly 180 degrees from the incident light. It is hard to explain that as a refractive effect.
  13. Oct 22, 2015 #12
    Thank you Briggs for explaining why I'm wrong. I tried to argue with my sister that Wikipedia does provide some reliable info, but she still says not to use it. I listened to her because she's 20 and i'm only 14.
  14. Oct 22, 2015 #13


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    I find wikipedia to be an excellent place to go for a general overview of a topic. The places where wikipedia is unreliable tends to be in the details of more advanced topics. But that's okay. It's just an encyclopedia, not a textbook. Don't use wikipedia for school projects, and always check the references if you're unsure about the validity of the page.
  15. Oct 23, 2015 #14
    That's why I don't use it. I'm studying FTL(Faster Than Light) and it's a bit difficult to study when you don't have the resources to do so. Everything, and I mean everything, I have to research has to do with advanced physics.
  16. Oct 23, 2015 #15
    Is the color of the sky part of these advanced topics in Physics that you research?
  17. Oct 23, 2015 #16
    No. But it is for the stuff I research. What Drakkith said is true. I research FTL theories, Special Relativity, properties of quarks, anti- particles, properties of gravity, and properties of light.
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