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Optics - rainbows

  1. Dec 6, 2005 #1
    I was wondering how a rainbow would look like when sitting in a lowflying plane. I was thinking that it sould still be a bow as standing on a mountain doesn't change the shape of the rainbow either. But is that really true?

    hexa
     
  2. jcsd
  3. Dec 6, 2005 #2
    You see a rainbow depending on the position you look at it because the phenomenon responsible for it, ie dispersion, is an "angle dependent" physical process. more specifically, EM-radiation splits up into the different constituent frequencies (colours) when passing through a medium of variable refractive index. each frequency is "emitted" along a certain angle with the incident EM-radiation.

    marlon
     
  4. Dec 6, 2005 #3
    ah very interesting. So the higher i get relative to the ground, the more I can see of that rainbow until I see the complete circle, right?

    Hexa
     
  5. Dec 6, 2005 #4
    I am sorry but i do not see how you come to such a conclusion ? Am I missing something here ?

    marlon
     
  6. Dec 6, 2005 #5

    russ_watters

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    Staff: Mentor

    What hexa concluded doesn't necessarily follow from your post, but it is more or less correct:
    http://www.wxdude.com/Rainbows.html

    and:
    http://www.wonderquest.com/rainbow-circle.htm
     
    Last edited: Dec 6, 2005
  7. Dec 6, 2005 #6
    ok, thanks for clarifying,

    my mistake

    marlon
     
  8. Feb 24, 2008 #7
    I realise that this thread has been dormant for a while , and I have no scientific knowledge as such but by observation .....

    If a rainbow were to be projected into a full circle the circle seems to complete itself at my feet . I noticed this particularily when driving in spray that the rainbow in the distance could be seen through the spray and seemed to come through 360 deg back to the ground beneath me .

    Is this true of all rainbows to the observer ?
     
  9. Feb 24, 2008 #8

    NoTime

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    Science Advisor
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    What you see depends on your vantage point in relation to the dispersing medium and the Sun.
    From personal experience, flying planes, I've seen them make full circles (quite impressive), but they are somewhat below you.
     
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