Unusual Double Rainbow at Zoobie Brush Shelter

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The discussion centers around the phenomenon of double rainbows, sparked by a user sharing a picture of one. It explains that double rainbows occur due to light reflecting twice within raindrops, creating a primary rainbow and a fainter secondary rainbow with reversed colors. The primary rainbow has red on the outside, while the secondary has red on the inside. This optical effect is common but often faint, making it less frequently observed. The conversation also touches on the visual beauty of rainbows and personal experiences of observing them, emphasizing the joy and wonder they inspire. Additionally, links to further resources and lectures on the topic are shared for those interested in a deeper understanding of the science behind rainbows.
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I caught this picture of an unusual double rainbow yesterday after a shower near the zoobie brush shelter here:
firstbatch013.jpg
 
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How can you get two rainbows at once?
 
Two rainclouds.
 
Its called a fogbow, i think (or could be Supernumerary rainbows)

http://www.philiplaven.com/p2b.html
http://www.sundog.clara.co.uk/rainbows/supers.htm

You can watch the detailed lecture here:
http://mfile.akamai.com/7870/rm/mit...870/8/8.02/videolectures/wl-802-lec31-220k.rm

One sure way to distinguish it is by looking at colour bands themselves. As you can see one has red on outside and one has red on inside, that's why you know its the same rainbow

Also just by looking at the rainbow you can tell what kind of pollution there is in the area

http://www.sundog.clara.co.uk/droplets/fogdrpsz.htm
 
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russ_watters said:
Two rainclouds.
Haha no.

Note the second rainbow is reversed.

A double rainbow occurs due to a second internal reflection within the raindrops. I good description wouldinlcude a diagram of the refraction properties of the drop of water, but I could not find any online.

Here is a brief explanation from theweathernetwork.com:

Double rainbows are not unusual, in fact, they occur with every rainbow. It's just that they are rarely bright enough to be seen.

When white sunlight enters each raindrop, it bends. The bending breaks light into its rainbow colours. The light then reflects off the back of the raindrop. On leaving the drops the light bends again. [Each raindrop scatters the full spectrum of colours, but you will see only a single colour from each drop]. Sometimes light reflects twice inside the raindrop. This action will form two rainbows: a primary rainbow that is produced by the first reflection of light and a larger secondary bow above the first, produced by the second reflection.

Colours in the secondary bow are in reverse order to those in the primary rainbow, with red on the inside and violet on the outside. Since only a small number of rays experience this double reflection, the secondary bow is always fainter than the primary.
 
DaveC426913 said:
Haha no.
I stand corrected. :redface: I guess that should be obvious since they are always concentric...
 
i never noticed that they were opposite like that...

i saw a reall cool one at the mall over the spring. both rainbows were clear from end to end. and the brighter one was absolutely amazing. it looked painted into the sky, mirrored so beautifully by the second one.
 
We caught a rainbow on Sandstone Peak on Sunday. I'd show you the picture but I'd have to upload it. And actually, I can't even find the camera at the moment.

Your double rainbow is very pretty.
 
wow two pots 'o gold!
 
  • #10
Hey Zoob,

Looking over the Conejo and San Fernando valleys, from the highest peak in the Santa Monica range on Sunday:

DSCN0025.jpg


The intensity isn't as great as yours. But we enjoyed it!
 

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