Readers’ wildlife photographs

Today we have some moon shots, the first from Nicole Reggia:

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And this one from Stephen Barnard:

Here’s a modest attempt at astrophotography. The color cast is due to the moon being slightly obscured by a wispy cloud illuminated by the setting sun.

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Stephen threw in a bull moose (Alces alces):

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. . . and a landscape photo from last Sunday:

There was an intense rainbow this morning, right over the eagle nest. You can see a faint double rainbow in the photo. I was surprised that the progression of colors is reversed on the secondary rainbow with respect to the primary one. I never realized this before, so I looked at some google images and it checked out. Maybe one of your readers can explain the physics behind this because I’m at a loss.

Stephen later got the answer, but I’m leaving the answer to the readers: why are the colors reversed in the “secondary” rainbow?

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21 Comments

  1. jaxkayaker
    Posted October 5, 2016 at 8:12 am | Permalink

    The rainbow is god’s promise not to destroy the earth by flood. The second rainbow is reversed because god went back on his promise.

    • HaggisForBrains
      Posted October 6, 2016 at 4:45 am | Permalink

      😀

  2. eric
    Posted October 5, 2016 at 8:15 am | Permalink

    why are the colors reversed in the “secondary” rainbow?

    My offhand guess is: because what you’re seeing is a reflection of the primary rainbow, not a second independent refraction of sunlight through water. Like any reflection, the mirror image you’re seeing is an optical reverse of the original.

    • Posted October 5, 2016 at 12:39 pm | Permalink

      You got it! I know this is true.

      • Stephen Barnard
        Posted October 5, 2016 at 9:19 pm | Permalink

        Not correct, I’m afraid.

  3. Mark Sturtevant
    Posted October 5, 2016 at 8:46 am | Permalink

    I looked up the answer about the inverted rainbow, but I decided not to spill the beans so others’ can explore.

  4. Stephen Barnard
    Posted October 5, 2016 at 8:50 am | Permalink

    We’re “unweaving the rainbow”. 🙂

  5. Posted October 5, 2016 at 9:29 am | Permalink

    Leaving aside the rainbow explanations, I find all of the photographs verging on the ethereal.

    Carl Kruse

  6. Steve Brooks
    Posted October 5, 2016 at 9:55 am | Permalink

    My guess is that the image on the right is a reflection of the image on the left. As a reflection, the features of the reflected image are reversed.

  7. ThyroidPlanet
    Posted October 5, 2016 at 11:41 am | Permalink

    I’ll just put this here:

    http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/rbowpri.html

    … it was not a pleasant googling experience.

    • Stephen Barnard
      Posted October 5, 2016 at 1:04 pm | Permalink

      That explains it pretty well.

      Why was your googling experience unpleasant? That was my first hit searching for “double rainbow physics”.

      • ThyroidPlanet
        Posted October 5, 2016 at 2:26 pm | Permalink

        I stated with “reverse rainbow”. Take a look. A few more keywords and my beloved Hyperphysics was spotted.

    • Mark Sturtevant
      Posted October 5, 2016 at 1:07 pm | Permalink

      Yep. Rainbows are made from refracted AND reflected light from inside raindrops. The color sent to us is the color heading our way from different raindrops in different positions.

      The secondary rainbow is not really a reflection of the primary rainbow, but is instead made once again by reflected and refracted light from raindrops at a different position. The angle is different, and so the colors come at us in reverse order. Why the order is reversed is explained at your link. It is not easy.

  8. Posted October 5, 2016 at 12:39 pm | Permalink

    Gorgeous photos, All.

  9. jimroberts
    Posted October 5, 2016 at 12:57 pm | Permalink

    Reflection proponents: what is the second rainbow reflected in? In the rare case of a triple rainbow, the colours are the original way round again – reflection of the second rainbow?
    Multiple reflections are indeed involved.

  10. Yevaud
    Posted October 5, 2016 at 1:05 pm | Permalink

    For an answer to the reversed colours in a secondary rainbow, I recommend a look at
    http://www.atoptics.co.uk which also explains lots of other atmospheric phenomena and has photos of them too.

  11. Heather Hastie
    Posted October 5, 2016 at 2:28 pm | Permalink

    Lovely photos! The blue in Nicole’s pics is beautiful!

  12. keith cook +/-
    Posted October 5, 2016 at 3:01 pm | Permalink

    Moon in blue
    and a rainbow two
    the moose is contemplating

    meanwhile the landscape goes on,
    and on and on.

  13. Andrew
    Posted October 6, 2016 at 9:25 am | Permalink

    Here is a good visual explanation of the double rainbow. Essentially, the primary rainbow is from the first internal reflection of light inside the raindrop and the secondary bow if from the second internal reflection. So actually, it’s the primary bow that has the reversed colors. Even numbered bows have the correct order.


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