Rainbow

Discussion in 'Chemistry' started by timojin, Sep 14, 2017.

  1. timojin Valued Senior Member

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    Very interesting observation and posting. Thank you ..
     
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  3. James R Just this guy, you know? Staff Member

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    No. As long as light enters the droplet, bounces off the back surface and then refracts back out at you, the exact geometry doesn't matter.
     
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  5. exchemist Valued Senior Member

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    I hope to God you do NOT revive that thread. I recall you advanced some very silly ideas about clouds, which you clung to in spite of explanations from several of us.
     
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  7. timojin Valued Senior Member

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    You are putting a restriction "droplet, bounces off the back surface and then refracts back out at you" What about between spherical shape and elliptical shape were the elliptical shape is 45 degree off ?
     
  8. timojin Valued Senior Member

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    They were silly to you but I am not satisfied with the explanation.
     
  9. James R Just this guy, you know? Staff Member

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    What about them? Why don't you suggest why that would be a problem, if you think it would be?
     
  10. timojin Valued Senior Member

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    I suppose for the sake of appearance there is no problem . My point is the incidence of light into the particle is distance A and the exit will be A + a for an elliptical shape and for a spherical incidence and exit is the same . And so the rainbow colors should be different ?
     
  11. Michael 345 Valued Senior Member

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    Your forgetting square droplets with black outside walls with only a microscopic pinhole for light to go in but not out
    If the light is absorbed inside would we see a rainbow if we cut it open?

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  12. James R Just this guy, you know? Staff Member

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    You only see the rainbow when the angles are just right to reflect the light back into your eyes. In fact, it's true to say that even two people standing next to each other see different rainbows; they each have their own set of water droplets that is producing their individual rainbow.
     
  13. superstring01 Moderator

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    While I was driving home --back to St. Petersburg, FL-- after Hurricane Irma, I saw a rainbow. I felt like Jesus was telling me something.
     
  14. Dinosaur Rational Skeptic Valued Senior Member

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    You can see a rainbow when it is not raining on you.

    Those who think otherwise should experiment with a lawn sprinkler.
     
  15. Dinosaur Rational Skeptic Valued Senior Member

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    BTW: Most rainbows are less than a complete circle due to being cut off by the horizon. Small ones can be created by lawn sprinklers.

    A circular rainbow is called a glory. In nature they are only seen from high altitudes like being mountaintops or near to a mountain top.
     
  16. DaveC426913 Valued Senior Member

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    An elliptical droplet still has the geometry of a spherical droplet. There will always be a section of the surface that is at the correct angle - it might just be a little narrower or wider.

    And it's not easy to get an elliptical droplet, unless it's falling rapidly, in which case your rainbow might be rather fleeting.
     
  17. Kittamaru Now nearly 40 pounds lighter. Staff Member

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    Ultimately, the restriction doesn't matter - water will, in nature, always attempt to form a spherical form due to the force of the water molecules attempting to pull towards one another. Excepting outside interference, there should always be some amount of refraction - the question, I would imagine, becomes one of intensity (is it bright enough to be visible to us)
     

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