Readers’ wildlife photographs

October 5, 2016 • 8:00 am

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 thoughts on “Readers’ wildlife photographs”

  1. 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.

  2. 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.

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

  6. 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.

    1. That explains it pretty well.

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

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

    2. 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.

  9. 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.

  12. Moon in blue
    and a rainbow two
    the moose is contemplating

    meanwhile the landscape goes on,
    and on and on.

  13. 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.

    http://i.stack.imgur.com/HgSyj.jpg

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