AWESOME RAINBOW! Is this constructive interference?

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Justin W

AWESOME RAINBOW! Is this constructive interference?

Post by Justin W » Fri Oct 02, 2009 4:20 pm

Howdy all!

I managed to capture a few shots of this sweet rainbow the other day.

This one, like others I've seen on occasion before, had a primary bow then a dimmer secondary bow, with the spectrum of the secondary bow being inverted from the order of the colors in the primary.

We noticed the bright prime bow first, then watched as the secondary bow brightened up. We couldn't turn our eyes away. As we observed this gorgeous phenomenon, it seemed the sky in that area was full of colors! By walking down further in the yard I was able to see why; Along with the prime and secondary bow, there were seemingly infinite sub-bows between them that one could sorta only glimpse from the corner of the eye.

Minutes later the odd bow formed, swinging an entirely different arc than the prime and secondary bows. In an effort to sound scientific and smart in front of my folks, I guessed the odd bow to be the result of constructive interference between the prime bow and the secondary(s).

Is that what's happening here?
Attachments
Rainbow shot.jpg
Look hard for a moment then look easy for an additional moment and you'll note the odd bow.
Rainbow shot.jpg (252.62 KiB) Viewed 26572 times

dave battin

AWESOME RAINBOW! Is this constructive interference?

Post by dave battin » Sat Oct 03, 2009 2:52 pm

I’ve seen this multi rainbow effect numerous times when out on the boat on long island's north shore, which is filled with many tiny harbors inlets and what ever. The secondary rainbow is probably a reflection from a body of water, pool or even a reflective surface. Check this nice explanation i found

"To see a rainbow, your eyes, the rain, and the Sun have to be lined up just right The sun has to be behind you, shining into rain that's falling off in the distance. The Sun has to be low enough in the sky for the light to hit the raindrops and come back to you at an angle of almost exactly 42 degrees, because of the way water refracts, or bends light. The light comes from behind us into the raindrops and is refracted (bent) back toward our eyes."

I remember one time seeing two perfect rainbows each opposite one another with the UV sides of the rainbows closest and slowly converging together as we approached the Huntington Bay inlet. As these two rainbows approached they turned the sky-space between them a dark dark blue, then they simply disappeared……….

I remember thinking, wow this reminds me of a good trip I took in the mid 70s! :whistle:

dave battin

AWESOME RAINBOW! Is this constructive interference?

Post by dave battin » Sat Oct 03, 2009 3:25 pm

Oops sorry, this is not interference its diffraction! :angel:

BobH

AWESOME RAINBOW! Is this constructive interference?

Post by BobH » Sun Oct 04, 2009 2:27 pm

Might want to send it in to Spaceweather.com for their expert's analysis and explanation.

favalora

AWESOME RAINBOW! Is this constructive interference?

Post by favalora » Mon Oct 05, 2009 2:44 am

This is my favorite* web site of atmospheric optical effects: http://www.atoptics.co.uk/. I think they describe the effect you saw as a "reflection rainbow": http://www.atoptics.co.uk/rainbows/reflect.htm.

-g

* Okay, actually, this is the only one I know about.

Colin Kaminski

AWESOME RAINBOW! Is this constructive interference?

Post by Colin Kaminski » Thu Nov 05, 2009 7:22 pm

This rainbow looks like it was created from two point sources. Otherwise the rainbows would be concentric. Perhaps behind you were two holes in the clouds or a body of water or something. I have not seen anything like this but I do see triple rainbows all the time.

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