12 Aug 10
Originally posted by sonhouseI think a minimum size is required, but beyond that it doesn't matter. You generally don't see a rainbow in clouds, only in rain (or other sprays of water droplets).
I assume the droplets have to be a certain sized, small window of opportunity, for a rainbow to be visible, so you wouldn't just be near a normal cloud with your hot air balloon. You would have to find the right conditions first. Maybe seeing a rainbow, then launching? Anyone have info on how long a rainbow remains visible from a single spot?
In general, if you want to see a rainbow in actual rainfall, you need the sun behind you and the rain in front of you and an unobstructed path from the sun to the rain and back. This is why we normally see rainbows after the rain has passed us and the sky is clearing up - hence the Biblical myth that a rainbow is a promise that the rain is over.
12 Aug 10
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I have failed to find any references to triple rainbows. It is my understanding that the first and second result from internal reflection, is it possible that triple internal reflection cannot occur? If it did, what angle would the rainbow be at?
I don't think a triple reflection would go towards the observer.
12 Aug 10
Originally posted by twhiteheadI googled "triple rainbow" and got a lot of results, including pictures.
I have failed to find any references to triple rainbows. It is my understanding that the first and second result from internal reflection, is it possible that triple internal reflection cannot occur? If it did, what angle would the rainbow be at?
I don't think a triple reflection would go towards the observer.
12 Aug 10
According to http://www.jal.cc.il.us/~mikolajsawicki/ex_optics.html, the third and fourth rainbows appear behind you, which means you need to be looking towards the sun, which makes it harder to see. They're also fainter. He reckons that six or more have been observed in lab conditions.
13 Aug 10
Originally posted by FabianFnasThe first one, is a reflection off the water.
[b]Take a pick: http://www.google.se/[WORD TOO LONG]/b]
The second, is what is know as a 'supernumerary rainbow'
I cant tell what is causing the third one, but it definitely isn't a third arc.
In the fourth, I can't see a third bow at all.
The fifth shows more 'supernumerary rainbows'
Must I go on?
13 Aug 10
Originally posted by twhitehead"Must I go on?"
The first one, is a reflection off the water.
The second, is what is know as a 'supernumerary rainbow'
I cant tell what is causing the third one, but it definitely isn't a third arc.
In the fourth, I can't see a third bow at all.
The fifth shows more 'supernumerary rainbows'
Must I go on?
If you like. You don't have to.
13 Aug 10
Originally posted by FabianFnasSo do you agree that triple rainbows are not normally seen in practice and all those photos are of other phenomena? I mean I could photograph a double rainbow and its reflection in two mirrors, but could I claim to have seen a sextuple rainbow?
"Must I go on?"
If you like. You don't have to.
13 Aug 10
Originally posted by twhiteheadIf you say so. I don't mind.
So do you agree that triple rainbows are not normally seen in practice and all those photos are of other phenomena? I mean I could photograph a double rainbow and its reflection in two mirrors, but could I claim to have seen a sextuple rainbow?