Talk:Rainbow

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[edit] older entries

The following article was copied from an E-newsletter for the New Mexico Academy of Healing Arts:

/ Why you can never see the end of a rainbow? It doesn’t have one. Theoretically, the light continues to bend into a complete circle—a circle we can’t see because it is cut off by the horizon.

Most people know the colors of the rainbow: red, orange, yellow, green, blue, indigo, violet. But few have been fortunate enough to see some of the rare manifestations of this natural phenomenon. Some rainbows are all purple, all red or even all white. Purple rainbows are only seen before or at sunrise. They can be formed by high clouds that scatter the blue and violet light, which raindrops reflect back to the observer. At sunset, when the sun is low in the sky, a rainbow may be a dramatic red arc, because the shorter wavelengths (blue, green and yellow) have been dispersed during their relatively long trip through the atmosphere.

White rainbows can appear in daylight or moonlight, but for entirely different reasons. During the day, rays of sunlight may be reflected from very small droplets of moisture—so small that the emerging bands of color are close enough to overlap, creating white light. But a white rainbow seen by moonlight is not white at all. It only seems so because the eye cannot detect color in light as weak as what the moon is reflecting. However, a photograph of a lunar rainbow, taken at the correct exposure, will be full in color.

The "rainbow" article should address some of the other colored rainbows that, though, rare, can happen from time to time.

Last night I saw the strangest and maybe the most rare form of rainbow. I have never heard of this but I can only describe it as a black rainbow. It was late in the evening and the sun was far below the horizon. The light was a very deep red and reflecting off of the clouds. In the east against a dark background of clouds appeared a very faint purple rainbow. I guess, since only red light was present, the resulting spectrum appeared only purple. Has anyone else seen one of these? How can I find out more?

Very nice diagrams of refraction (with the red lines). Very good at explaining the phenomenon.

---

I think that a rainbow is visible only when the sun is at a low altitude- mornings and late afternoon/ evenings. Isn't there some specific angle for this? KRS 15:33, 1 Feb 2004 (UTC)

I added: Hence there is no rainbow if the sun is at a higher altitude than 42°: the rainbow would be below the horizon. --Patrick 23:30, 1 Feb 2004 (UTC)

Nevertheless, it is not true, as sometimes one can look below the horizon. For example, if you are looking down from a mountain, or - as mentioned in the article! - from an aeroplane.

I've deleted the incorrect reference to glories from the aeroplane comment. Glory is a different optical phenomenon from rainbow and it is incorrect to state that a full-circle rainbow is a glory. This error needs to be removed from the page Glory_(rainbow) and I've put that on my task list, but I'm not sure how to fix the problem that the error is incorporated into the page title. Advice welcome. --Richard Jones 13:45, 20 Mar 2004 (UTC)

I've moved it to Glory (optical phenomenon). ––wwoods 18:12, 21 Mar 2004 (UTC)


Added: Even more rarely is a triple rainbow seen and a few observers have report<link rel="stylesheet" type="text/css" href="http://en.wikipedia.org/w/index.php?title=User:Lupin/navpop.css&action=raw&ctype=text/css&dontcountme=s">ed seeing quadruple rainbows in which a dim outermost arc had a rippling and pulsating appearance. - Sounds fantanstic, but I saw this, and I was not the only one - Leonard G. 03:50, 25 Aug 2004 (UTC)

[edit] Angle derivation

The article does a clumsy job about what is special about the 42° or the 52° angle. The picture lead me to correctly see that light can be refracted-internally.reflected-refracted.again at a large range of angles, its just that 42° is where the largest intensity of refraction occurs. The page http://www.phy.ntnu.edu.tw/java/Rainbow/rainbow.html has a much better explanation for the angle. 129.42.208.182 21:46, 30 Aug 2004 (UTC)

Yes, I agree with the comment offered above: I think the crucial part of the linked article is where it says "The rainbow is actually a disk of scattered light, but it is brightest at the edge; the disk for different wavelengths is a different size, and that is why we see the color effects there." In other words, the difference between the rainbow and a pure spectrum made by a prism lit from a slit is this: In the prismatic spectrum, each color has just one line position (if the slit is narrow), and the result of adding all those together is a sequence of approximately pure colors. But in the rainbow, each color has not so much a line, but rather an arc of light, with some thickness, it is brightest at its outer edge, but it also has brightness at distances away from that outer edge, fading away inwardly as one gets farther from the edge. So the rainbow color palette results from superimposing all those bright colored edges along with their adjacent areas of fading intensity for each color. This makes the resulting rainbow colors actually impure, compared with pure spectral colors resulting from a slit and prism. Another way to visualize this is to think of the rainbow as a chromatically-dispersed caustic: A caustic is like the curve of light that can be seen on the surface of a cup of milky coffee when it is lit from the side -- the lighted area has a sharp bright edge, but it's not purely a bright line, it has thickness, and its brightness gradually fades away from the maximally-bright curved edge. Every spectral color makes one of those caustics, but with slightly different diameter; and when they are superimposed on each other, there you have the rainbow.

[edit] Moonbow

I'm not clear on this section: In a very few cases, a moonbow, or night-time rainbow, can be seen on strongly-moonlit nights. As human visual perception for colour in low light is poor, moonbows are perceived to be white. In Hawaii, we see moonbows all the time, and it's possible to make out many colors. So, what does the editor (or author) mean by "in a very few cases"? --Viriditas 12:00, 29 Oct 2004 (UTC)

[edit] Triple Rainbows

The article states: Even more rarely is a triple rainbow seen and a few observers have reported seeing quadruple rainbows... These things are not rare in Hawaii. I've seen triple rainbows many times and a quadruple rainbow only twice. --Viriditas 12:32, 29 Oct 2004 (UTC)

More importantly we could use a scientific explanation of how they are possible. I've seen a 3+ rainbow and know that the additional bows cannot be explained using Descartes' internal reflections in a rain drop. -- Solipsist 08:32, 24 Nov 2004 (UTC)

I have personally seen a triple-banded rainbow that looked very much like the "supernumerary" rainbow pictured in the article; the colors in the rainbow I witnessed were red, orange, yellow, green, blue, violet, green, blue, violet, green, blue, violet. When I turned around, I saw that two small dense clouds close to the sun were extremely bright (almost as if I was seeing a reflection of the sun off an icy lake). I theorize that either those two clouds acted as second 'suns' bright enough to produce two more rainbows that overlapped the one from the sun itself, and that the combination merged into one supernumerary rainbow, or else that the supernumerary bands of the rainbow became visible due to the increased intensity of the sunlight from the reflections. It is extremely unlikely that the raincloud under which I saw that rainbow was producing raindrops all of a fixed size, as some web sites propose to explain supernumerary rainbows. The primary explanation may be wave interference as Thomas Young said, but I think there must be other requirements to explain why they are rarely seen. (I reverted my first entry here before anyone replied to it, when I realized it was a foot-in-mouth mistake). Aumakua 15:57, 2 December 2005 (UTC)


Im no expert on the subject of rainbows but have on occasions observed tripple rainbows over the coast, but once, around trwenty years ago, I had observed no less than twentyfive at the same time. These were much smaller than any bows i had prieviously observed. Each seemed to occupy its onwn space and at different angles; they were also very faint and hard to count. The time of day was an evening, about 5.30pm, late winter/spring, mostly overcast and after a good rainstorm. The location was England, cromer(a coastal town on the east),direction looking north-west to north over the sea horizon. I have read only once of someone observing the same atmospheric condition but have no knowledge as to the cause of this particular phenominon or the rarity of it. Sadly no images of it though.Maybe you guys that do understand these thing could spread some light of knowledge. The only explanation i can find so far is that of supernumerary rainbows.

[edit] Mnemonics

The main mnemonic described in the article is 'Richard of York...', given the subject am I right in thinking that this is only commonly used in the UK?

Another editor has also added 'Roy G. Biv' saying it is more common. I haven't heard this one, is it common in the US? -- Solipsist 08:43, 24 Nov 2004 (UTC)

I don't know about the US, but it is common in Australian schools. - Jeff Parsons (sorry, no account yet)
Yah, it's common in der Staes Flip Merav 21 10:40, 3 June 2006 (UTC)
It's what we use in Australia.
I'm an Aussie and know both, although I learnt the Richard of York one first. 58.105.82.209 03:11, 5 September 2007 (UTC)
Sorry, forgot to log in.I am a lemon 03:12, 5 September 2007 (UTC)

[edit] Total internal reflection?

The article states that light is reflected from the back of the drop under total internal reflection. I find this statement rather dubious at best. A quick derivation from snell's law shows that the minimum angle for total internal reflection in water (using nw = 1.33) is 48.7 degrees. That would imply that the angle at the back of the droplet is greater than 90 degrees, which by inspection is not the case.
Since light would therefore leave the back of the drop refracted, would it not be impossible to see a rainbow between the observer and the sun, if the appropriate areas of the sky were unobscured?Kenneth Charles
Edit: I did some research. Light is indeed passed out the back of a droplet, but due to the fact that there is no distinct peak of emission from this spectra, it does not form a visible rainbow. However, the statement that light is totally internally reflected inside a raindrop is wrong and should be removed.

[edit] Mythology and religion

Galileo wrote a treatise on the properties of light? I'm not familiar with this at all. If no one can provide a citation, we ought to change it to Newton, who certainly did study light and color.

It perhaps should read 'Descartes treatise'. -- Solipsist 09:22, 23 Jun 2005 (UTC)

It now credits Descartes and his (unknown) predecessor Theodoric; see below. Dandrake 03:01, 11 December 2005 (UTC)

[edit] Flask experiment

In the article Theodoric of Freiburg it is described that he did experiments with spheric flasks as models for water drops. Here in the rainbow article it is reported about Descartes. Which is true? Or both? Ikar.us 2005-06-29 11:02:14 (UTC)

They both did. See for reference:

Jondor 29 June 2005 21:56 (UTC)

[edit] reflection rainbow - a contradiction

It says: Where sunlight reflects off water before reaching the raindrops, it produces a reflection rainbow.

Then it says: A reflected rainbow is produced when light that has first been reflected inside raindrops then reflects off a body of water before reaching the observer.

So which one is it? Thanks, Ladypine 18:15, 21 January 2006 (UTC)


Reflected versus reflection. -- ALoan (Talk) 18:31, 21 January 2006 (UTC)

Thanks, I seperated the paragraph to make it clearer.Ladypine 18:34, 21 January 2006 (UTC)

[edit] Images / German article

There has been some to-ing and fro-ing on the images recently (I cut some out and replaced with ones from Commons:Rainbow).

Which of the two following should appear as the lead image:

A rainbow arches over Florida.

A complete half-circle rainbow at Lake Zurich.

the end

waterfall

Secondly, my German is not good enough to extract more information from the excellent article in German Wikipedia. If someone can help, I should be very grateful. -- ALoan (Talk) 19:01, 21 January 2006 (UTC)

Now the Florida image is again there. I think it is the least impressive of all and should be replaced by any of the others. --Ikar.us 21:46, 13 March 2006 (UTC)
I agree. User:Desmond71 keeps putting the Florida one back for some unknown reason. -- ALoan (Talk) 00:06, 20 April 2006 (UTC)
I believe the Florida image serves as a much better lead image than the current Lake Zurich image because the main focus of the Zurich image is that of a brightly lit boat in the foreground and not of the rainbow. (The rainbow appears too dark and is almost lost among an even darker background, especially when viewed on darker monitors.) The Florida image, though admittedly not the best image around, at least does a much better job of illustrating the rainbow and therefore makes for a better lead image. I have absolutely no problem with the Zurich image that User:ALoan keeps using, but I feel it should be displayed elsewhere in the article rather than as the lead image. (I have tried contacting User:ALoan about this earlier, but I don't know how to send messages directly to users hear at Wikipedia.) -- Desmond71 17:39, 8 June 2006 (UTC)
Hi, Desmond71 - it is good to hear from you at last. The easiest way to contact me is by leaving a message at User talk:ALoan (I left some messages for you at User talk:Desmond71 a while ago, but got no reply). Fortunately, I am watching this talk page too.
I'm afraid that I just don't like the Florida image very much. I see what you mean about the Geneva image being dark, with too much emphasis on the boat; on the other hand, it shows an almost-180-degreee rainbow. The "end of the rainbow" image is also quite nice (and a featured picture but the trees are a bit of a distraction. The waterfall is also not a perfect example, and none of the others at Commons:Rainbow is perfect either... -- ALoan (Talk) 13:46, 9 June 2006 (UTC)

[edit] Literature section needs complete rewrite

The section "Rainbows in literature" is horrible. It does not give any explanation or information about the view, the inclusion, the metaphoric usage... of rainbows in Literature. It just features some verses. How could this be descriptive of the section's title. CG 20:23, 23 February 2006 (UTC)

{{sofixit}}. Other than the instances cited, do you have any views on the "view, the inclusion, the metaphoric usage... of rainbows in Literature"?
That section is still the same, 15 months after the first comment. Does anyone have the necessary expertese to write a paragraph of prose about how rainbows have been used in literature? Neil Dodgson 14:35, 21 May 2007 (UTC)

[edit] A photo of a rainbow taken from an airplane should be introduced

I have heard that rainbow looks like different when viewed from a high place - that it is not an arc in this case but rather a ring. Someone should put an effort to get a photo of a rainbow from a plane or a high mountain

It is true, the photo on this (http://www.wunderground.com/wximage/viewsingleimage.html?mode=singleimage&handle=JeffMasters&number=0) page proves it. Not sure if it can be used here, I can't find the legal mumbo-jumbo.
In general, you see a part of a circle, depending on where the water is relative to you and the sun. Being up in a plane with lots of water below you is the best way to see the whole circle, but it's not really a difference of kind, just a better viewpoint. Notice in the picture you posted that you don't see the full circle, because there's a plane in the way, and no droplets between you and the plane. The ground does the same thing, often, especially when the rain is in the distance; if it's raining where you are, you can sometimes see the rainbow extend all around you. Dicklyon 19:25, 26 July 2006 (UTC)
Yeah, but there's an explanation about the image, and it's the best I could find. --DragonSparke 19:52, 26 July 2006 (UTC)

A rainbow seen from above is called a pilot's glory. It differs from the normal rainbow because the order of the colors is reversed (two internal reflections in the water droplets.) Also, the sahdow of teh airplane is in the center of the rainbow circle. -Arch dude 02:50, 19 May 2007 (UTC)

[edit] The end of a rainbow

The article contradicts itself, in the Rainbows in religion and mythology section it says, "The Irish leprechaun's secret hiding place for his crock of gold is usually said to be at the end of the rainbow (which is impossible to reach)." and yet, right next to it shows a photo [5] which shows the end of a rainbow. Someone should fix this or tell me why I'm wrong ;) WikiSlasher 12:01, 15 June 2006 (UTC)

You can see the end of the rainbow (or, at least, in general terms, roughly where it ends) but please let us know how you get on in reaching it... -- ALoan (Talk) 14:13, 15 June 2006 (UTC)
OK I'll admit...I haven't tried reaching it, I guess it might move a bit as you approach it, I don't know because I haven't tried it, but it seemed like a contradiction so I just thought I'd get that cleared up. Perhaps if you use a long stick to reach it that'd help! :) WikiSlasher 13:32, 16 June 2006 (UTC)
Rainbows are actually a ring, but this is only evident when you see the rainbow from above the ground, from the land, it appears as an arc. So, really, there IS no end to the rainbow. If you chase that pot of gold, you'll never reach it, and get VERY dizzy. Hope this helps clear it up. ^^ --DragonSparke 17:39, 26 July 2006 (UTC)
It is easiest to practice reaching the end of the rainbow using a small example in your back yard. Choose a sunny summer evening and set up a sprinker or hose to give a fine spray of mist. Then stand between the sprinker and the sun with your back to the sun. You should be able to see a rainbow that appears to be just a couple of meters across, but you will still have fun trying to reach the end where it touches the ground... -- Solipsist 17:12, 11 August 2006 (UTC)
There is a magnificent image of a fully circular primary rainbow at http://www.roddyscheer.com/photo_detail.php?photo=913. I presume that this image was taken from a hang glider. As the image belongs to professional photographer (Roddy Scheer), the image must NOT be added to this Wikipedia entry - but a link could be permissible.
The end of your rainbow comes to you. The region in space formed by the water drops which generate the rainbow light is shaped like a cone. The axis of the cone is defined by the shadow of your head. As long as there are spherical drops of water and parallel rays of light then the base of the cone can be infinitely far from you. So when you look at a rainbow, the sunlight comes from behind you, hits water drops on the surface of the cone and then is refracted and reflected down the cone to its apex which is located at your head. If you are close enough to the shower of water drops you can see two rainbows, one for each eye. Each observer sees their own rainbow and each observer is at the apex of their own rainbow. If the apex of an infinite cone that channels light towards its apex can be thought of as the end of the cone then it's also the end of the rainbow. You, your eyes, are the end of the rainbow. Maybe the leprechaun's secret is that you shouldn't be running around the country-side looking for material wealth because the rainbow reminds you that the most valuable wealth is found within you.

Malqum 22 June 2007 Malqum 08:29, 22 June 2007 (UTC)

I just made a short animation showing how the rainbow comes from a cone-shaped region but appears to be a circle. You can see it by searching on YouTube for "malqum" or at http://www.youtube.com/watch?v=PXWiE3TX3p4 Malqum 02:06, 12 July 2007 (UTC)

[edit] Culture

"CULTURE" -- A small comment but from my perspective as an anthropologist, important. The heading "rainbows in mythology and religion" is in the current form separate from "rainbows in culture"; and the "rainbows in culture" includes literature and art. This implies that non-literate peoples, or religion, or mythical beliefs are not part of "culture" (or more ironically, that culture is not inclusive of myth!). More specifically, this structure of headings seems to reify the use of the term "culture" to mean something like "I got culture because I go to the opera" as opposed to culture as the full behavioral repertoire of our species, etc. I'm sure none of the darker side of what is implied in my comment (racism, ethnocentrism, etc.) is intended at all! And it is a simple fix, just use "rainbows in culture" as the main heading and subsume myth, religion, literature, etc. under that heading. --Greg Laden

Good idea. So just fix it instead of pontificating about it. Dicklyon 19:35, 19 June 2006 (UTC)

[edit] Indigo

I've removed the sentence in the mnemonics section suggesting indigo is not regarded as a colour of the rainbow, and also re-added it to the introduction. Using a simple google search seems to reveal that most sources still list Indigo, as do all the mnemonics actually mentioned:

I believe these searches reveal all instances of the colours appearing in those orders, with or without commas and other punctuation in between.

Cheers — SteveRwanda 12:59, 11 August 2006 (UTC)

I think you're missing the point. Yes, it is conventional to include indigo in the sequence. But who do you know who can identify the color indigo? Or who can see a stripe of rainbow between blue and violet? The passage you removed captured the relationship between the conventional sequence mnemonics and the actual perception pretty well and neutrally, I thought. Dicklyon 16:54, 11 August 2006 (UTC)
Can you provide a citation for the paragraph (i.e. that humans are not able to perceive indigo)? -- ALoan (Talk) 17:01, 11 August 2006 (UTC)
Contemporary Color: Theory & Use, by Steven Bleicher, p.6 [6] says "However, most people can only discern six of these hues; they have trouble telling the difference between indigo and violet." Dicklyon 04:23, 14 August 2006 (UTC)
Excellent - please would you add the citation to the paragraph so the next time someone questions it, they can see the source for our assertion. -- ALoan (Talk) 11:03, 14 August 2006 (UTC)
I've now added that citation in the relevant spot. Just for the record, I wasn't questioning whether humans can see indigo in a rainbow, merely whether modern definitions always omit it, as the previous paragraph seemed to imply. I believe it's now more accurate and informative! Cheers — SteveRwanda 18:10, 15 August 2006 (UTC)
OK, point taken. I've restored the paragraph, though without the sentence most modern rainbow definitions do not include that as a distinct colour which I regard as untrue. It's kind of a repetition of what it says about indigo in the intro, but maybe that's the correct style for articles anyway - i.e. the intro is a summary of points in the article itself. Cheers — SteveRwanda 19:16, 11 August 2006 (UTC)
  • I have read an academic paper in which the author claimed that s/he had examined Newton's notebooks and worked out the wavelengths of the seven colours. This showed that what Newton called "indigo", we today would call "blue", and what Newton called "blue", we today would call "blue-green" or "turquoise". I've added an appropriate comment to the page. However, I have been unable to relocate that academic paper: I'll keep looking. — Neil Dodgson 12:05, 8 February 2007 (UTC)

I see no controversy in including indigo as a shade of the rainbow. Some people exhibit colour blindness towards almost any shade of colour some cannot see red for example, yet there is no section claiming that red is not a shade. 86.131.90.161 (talk) 16:43, 29 February 2008 (UTC)

[edit] Finally some decent photos

Thanks, Ceinturion, for the two new lead photos. Dicklyon 22:36, 26 August 2006 (UTC)

I am really glad that maker of the first lead photo (Eric Rolph) agreed to upload it to wikipedia. Ceinturion 22:02, 28 August 2006 (UTC)
One problem with that image is that its licensing is currently contradictory. The permission line inlucdes 'NonCommercial' and 'NoDerivs' which suggests that it should really be licensed as cc-by-nc-nd which is no longer an accepted license on Wikipedia. -- Solipsist 13:02, 1 October 2006 (UTC)
The history shows that he added the {{cc-by-sa-2.5}} license in a separate edit AFTER the "non commercial no derivs" initial license, so I would presume that license supercedes and we're OK. Dicklyon 19:14, 1 October 2006 (UTC)
Someone still ought to ask them to fix the licensing. -- Solipsist 16:26, 2 October 2006 (UTC)
It's hard to ask inactive User:Ericrolph anything. No user page, no talk page, no recent contributions. But give it a try, in case he logs in. Dicklyon 17:16, 2 October 2006 (UTC)

[edit] Redundant image of double rainbow

The new image of a double rainbow (Double_rainbow_2.jpg) does not really add anything compared to the existing image of a double rainbow (Regenbogen_NASA.jpg). Therefore I would like to remove the new image next week, but I don't want to offend the person who submitted it. If you think the new image is better than the old one, please explain it here. Ceinturion 22:02, 28 August 2006 (UTC)

[edit] My Rainbow

This seems to be the place to dump rainbow pics so here's mine. This one show's how close to the ground they can get. This one is hugging the hillside less than 15 feet away.--God Ω War 03:04, 29 August 2006 (UTC)

But there's no garage door in the picture. What's up with that? Dicklyon 03:45, 29 August 2006 (UTC)

[edit] ROYGBIV

The convention of seeing red, orange, yellow, green, blue... is not universal. Different cultures see the color breaks at different places. 67.120.92.193 01:34, 2 January 2007 (UTC)

Also, it isn't particular to rainbows. Don't merge. Melchoir 00:08, 24 January 2007 (UTC)

Close for lack of support even by the originator. Dicklyon 02:37, 24 January 2007 (UTC)

[edit] Why does the rainbow form an arc across the sky?

Scientific explanation of why the rainbow forms an arc would be a great addition to this page. Its the question I'm still left asking. Agelena 17:46, 25 February 2007 (UTC)

The rainbow forms at a constant angle from the direction that the sun is going. That makes it a circle. But you only get the part of the circle where there are raindrops in the sunlight. Dicklyon 17:53, 25 February 2007 (UTC)
Saying the same thing: It's the 40°–42° mentioned in the article -- wherever there are water droplets at an angle of 40° from you (as you are looking away from the sun), you'll see a spectrum. The set of positions which are 40° away from you are a circle (40° straight up, 40° to your right, 40° halfway-between-straight-up-and-to-your-right, and so on). (If I could write this more clearly, I'd add it to the main page :-) Hope that helps. not-just-yeti 18:00, 25 February 2007 (UTC)
Here's a good illustration I found on this page. Dicklyon 21:53, 25 February 2007 (UTC)

[edit] What is a reasonable number of images?

There was a time when this page was a dumping ground for people's pretty photographs of rainbows. I think the page now has a reasonable number of reasonably relevant images. Does anyone else have an opinion? Neil Dodgson 20:43, 11 May 2007 (UTC)

I sympathize with the issue, and have on occasion removed some rainbow photos myself, but I think each picture deserves some attention and a good reason for removal. Bulk removal with comments like "delete three images and some text as there are too many images on this page" is hard to distinguish from the typical vandalisms that I revert with comments like "revert unexplained removal". That is, "too many images" is a pretty broad opinion, not a reason for removing something. Dicklyon 02:04, 12 May 2007 (UTC)
I feel that the overriding issue is does each picture further help to further illustrate the point, and before the removal of "extra" photos most of the images present were in the same medium and same artistic style. I feel that the two pictures that were left up are good examples but my arguement is that the remaining examples show only oil paintings; I tried to include one of my own digital works to add diversity, but that was followed by a cry of "too many pictures", and "self promotion", I'm already known on the Internet as being an artist and that work is a slight variant on what is considered to be one of the most popular blotter art designs in the last few years (also my creation). I think removing the one example of digital rainbow art was a mistake, but I'm not going to repost it myself as I do not wish to impose my sensibilites on others- you decide. Rafti Institute 05:04, 12 May 2007 (UTC)
I can explain my removals, if that would help. (1) There were five oil paintings. William Rafti had previously pointed out to me that all of the paintings were in the same style (see his comment of 12 May 2007, above). I therefore chose the two of these that I felt were the best, noting there are references to pages for other artists. (2) There was a rather poor image of a woodcut with the twelve astrological signs for the zodiac. There was no reference to this in the text and it seemed to add nothing to the page. (3) There was an image of the gay pride flag, which has its own page, so does not need to be reproduced here. (4) There was a rather poor image of a rainbow taken from an airplane, which seemed to add nothing to the page. (5) What sparked this off was my removal of Mr Rafti's rainbow-inspired digital art. I removed that because it seemed rather too close to self-publicity for Mr Rafti to put his own art work up on the page; although I appreciate his willingness to donate his own art to Wikipedia. Neil Dodgson 12:20, 12 May 2007 (UTC)
Thanks for the explanations. You didn't mention the one I care most about, so how about restoring Georges Noblet's photograph "Harpe de Lumière", a very different take on the artistic use of rainbow? Dicklyon 15:25, 12 May 2007 (UTC)
Absolutely. Thanks for putting it back in. Neil Dodgson 18:39, 12 May 2007 (UTC)

Diliff removed two further images on 24 May: Rainbow of Hearts, which is an example of a rainbow in popular culture with permuted colours, and Harpe de Lumière, which I had previously removed and Dicklyon restored on 12 May. Do we want to put these pictures back on the page? Neil Dodgson 07:51, 26 May 2007 (UTC)

Rainbow of Hearts photo by Seng P. Merrill. In popular culture, the colours of the rainbow are sometimes permuted.
Rainbow of Hearts photo by Seng P. Merrill. In popular culture, the colours of the rainbow are sometimes permuted.
Harpe de Lumière, photo by Georges Noblet
Harpe de Lumière, photo by Georges Noblet
Sorry guys. I wasn't aware of a previous discussion regarding these photos. Obviously I left a reasonably detailed edit summary but I'll try to justify things a bit further. Perhaps I was a little hasty in removing them completely, but I felt that them existing under the section "Rainbows in art" was stretching the truth a little, particularly when captioned in a way that suggests these images are notable and published. They are personal artistic images that have been labeled art by a contributor, whether it be the creator or just a fan. Furthermore, since it is the image that is supposed to be speaking volumes on the subject of rainbows and not the artist, it is not common practise to include the name of the creator in the subject, except when it is relevant. Obviously art is in the eye of the beholder and I don't claim to be definitive on the subject, but I think that rainbows in art section should be limited to what is already considered popular/renown/valued art, particularly since we cannot be that devoid of public domain art on the subject of rainbows... In a nutshell, I was struggling to see a valid place in the article for the images, felt that they didn't really add value and were borderline self promotional, or at least promotional, as I don't know the link between the contributor and the original photographer. Diliff | (Talk) (Contribs) 12:57, 26 May 2007 (UTC)
artificial rainbow made in home garden, Islamabad
artificial rainbow made in home garden, Islamabad

User:Khalid_Mahmood introduced another image on 13 and 15 October. It is similar to an image which was deleted back in May 2007 (amongst the seven images that were deleted then). We are trying to keep the number of images on this page down to just those that are vital. The ones on the page seem to have general support. This new one is not a significant addition, therefore I have deleted it (twice). I am happy to debate this on the Talk page. Neil Dodgson 20:18, 15 October 2007 (UTC)

[edit] Inline references sorely needed

I'm glad to see FA was removed from this article...it does not fit the current standard for FA. Even for a GA, an appropriate number of inline references are needed. I could cover the page with fact tags as it stands right now. Without in the inline references, the article won't be able to elevate above B class. Thegreatdr 17:49, 1 June 2007 (UTC)

[edit] 18.75 octillion distinct colours

The following comment has been added twice by 193.238.80.100 to The sequence of colours section and removed twice by me:

Assuming visible light is from 400nm - 700nm in wavelength and using the minimum quantum measurement of 1 planck steps there are approximately 18.75 octillion distinct colours in the rainbow.

There are three issues here:

  • this sentence is unhelpful, requiring an understanding of quantum theory to know just what the author is trying to say;
  • the number of distinct perceivable colours in the rainbow is considerably smaller than this, owing to the limitations of the human eye, therefore this sentence will confuse people who assume that "distinct" relates to perception rather than quantum mechanics;
  • if this sentence is to be added to the page then this seems to me to be the wrong section to put it in.

Neil Dodgson 11:20, 20 June 2007 (UTC)

It's a neat idea, "how many colors in a rainbow", and I thought the reference to quantum theory is okay (the intent/derivation of that one statement was perfectly comprehensible to me, after 1yr of college physics). Although I'd quibble that it's unclear every frequency gets reflected inside (enough) raindrops, and I have no idea how many photons from the rainbow are reaching my eye even if every frequency is being reflected. So I'd be mildly in favor of putting the idea in somewhere, but mention that this has less to do with rainbows than the theoretical maximum number of colors in the visible spectrum. not-just-yeti 12:33, 20 June 2007 (UTC)
I agree with Neil that this doesn't belong in an article on rainbows. The Planck length is virtually unmeasureable, and so I don't see this as adding substantial information to the article. I'd be more interested in content about the eye's ability to perceive this phenomenon. — RJH (talk) 17:18, 20 June 2007 (UTC)

[edit] Bloodbow

I recall about 8 years ago seeing a rainbow while driving at sunset.. and as the sun set i caught sight of it and it had turned from your usual multicoloured glory into a bow of almost complete red.. it lasted only a few seconds... and was mostly obscured by the trees on the road i was on.. but was really awesome.

Is this a known phenomena?--Nasher 19:29, 27 June 2007 (UTC)

Yes, I've seen it too. The colours in the rainbow are refracted out of the sunlight which is usually white light so contains ROYGBV. As the sun gets closer to the horizon its light gets redder as wavelengths in the violet end of the spectrum get removed by the longer path of air the light travels through. So the sunlight that produced the red rainbow you saw may have had very little green, blue and violet. If the rainbow was also caused by very small drops of water then diffraction can blur the colours into a band of just one colour which could look quite red.Malqum 12:35, 28 June 2007 (UTC)
Oh thank God, I thought from the title that you were talking about the refraction of light in a fine mist of blood. 213.48.15.234 09:06, 3 July 2007 (UTC)

[edit] Change double rainbow photo?

Full featured double rainbow in Wrangell-St. Elias National Park, Alaska.
Full featured double rainbow in Wrangell-St. Elias National Park, Alaska.
Full featured double rainbow in Savonlinna, Finland.
Full featured double rainbow in Savonlinna, Finland.

I added some time ago another photo showing double rainbow. It was removed because the person felt that it wasn't necessary to have another photo of double rainbow.

But, I think my photo shows the whole double rainbow much better, so what are your thoughts removing the current and adding mine?

Upper one is current photo.

eQualizer 09:25, 22 August 2007 (UTC)

This is tricky. Both photos have advantages:
  • The current (upper) photo is clearer than the proposed (lower) photo. The rainbow is wider and brighter in the current photo.
  • The proposed photo shows a full double rainbow, whereas the current photo only shows two arcs from the secondary.
There isn't much in it. I tend towards keeping the current photo because it has a wider brighter primary. Neil Dodgson 14:57, 22 August 2007 (UTC)

Whatever image gets used, it may be beneficial if it could meet the WP:FP criteria. — RJH (talk) 17:53, 22 August 2007 (UTC)

I am in favor of the current photo. Although the proposed photo is more majestic, the current photo is more informative and educational because of the visible antisolar point (the shadow of the observer), the depth of the rainbow, and the absence of shrub shadows near the antisolar point. Ceinturion 18:30, 22 August 2007 (UTC)
The 'full featured double rainbow' is a very good photo and it really should be in the article somewhere. Especially since with the current photo, although it's also very good, as the caption admits the double part is not that clear. —Preceding unsigned comment added by ProfDEH (talk • contribs) 07:51, 28 February 2008 (UTC)

[edit] Gallery

The aesthetic nature of this subject matter makes it a natural for a gallery. This is also recommended by the MoS for articles that have too many images. I think a gallery section would be an appropriate addition to this page, and there are FA'd articles with a gallery. (E.g. Seattle,_Washington#Gallery.) Does anybody find this objectionable? (Yup I know there's a rainbow gallery on the commons.) — RJH (talk) 15:19, 6 September 2007 (UTC)

[edit] Reflection rainbow photo

Tlatla, the reflection rainbow picture that you added is great! I have been waiting for a picture like this for quite some time. I somewhat prematurely removed your statement that the reflection rainbow on the photo is due to sun rays reflected from water behind the camera. Could you indicate the location of the camera more precisely, for example by editing the following coordinates? 48°20′30″N, 122°33′30″W Ceinturion 06:56, 13 September 2007 (UTC)

[edit] Reflection rainbow Hellbus?

Hellbus, yesterday you added that the image that I copied here shows "both types" of rainbow. Given the history of the article I think that with "both types" you meant a reflected rainbow and a reflection rainbow, where the faint colorless vertical streak above the horizon is the supposed reflection primary. In my opinion that streak is not a convincing example of a reflection rainbow. Saperaud, who added the photo on 31 july 2005, just called it a double rainbow. As you've added your claim several times (17 august 2005, 28 february 2007, and 27 july 2007) I would like to know whether it is your personal interpretation or that you were present when the photo was taken. Ceinturion 10:08, 28 October 2007 (UTC)

[edit] Noahacian Deluge

I slightly reworded the section on the biblical view of rainbows, because it failed to take into account Christians who believe that the Noahacian Deluge was a local flood rather than a global flood, which is widely held belief among certain subsets of Christians. StaticElectric 19:42, 19 September 2007 (UTC)

[edit] Culture

The part of the "Culture" section that follows "Religion and mythology" seems especially weak to me. I think there should be more depth to the coverage, rather than just presenting a few examples. For example, rather than discussing the symbolic use of the rainbow in the "Literature" section, all it has is several quotes. These seem to add little to the content as they are not dissected for meaning. — RJH (talk) 16:49, 5 November 2007 (UTC)

Apart from the first quote, the quotes have been chosen to illustrate the cultural response to the discovery of the scientific explanation for rainbows. This fits with what goes before. Despite this, there could be much improvement in this section. — Neil Dodgson 14:27, 6 November 2007 (UTC)

[edit] Rainbow 'religion'?

Can anyone find confirmation of this? The paragraph has been inserted by two anonymous ip editors, or perhaps one editor on a cluster address, it sounds plausible, but I cannot find anything to confirm it. I'm going to add a fact tag to it for now. -- Geoff Riley (talk) 10:08, 10 December 2007 (UTC)

[edit] end of the rainbow

It is possible to see the end of the rainbow as I found out yesterday. We were travelling in a large thunder storm just south of Mirboo North, Victoria, Australia at approximately 7pm ADST. It had been a sunny 30 degrees celcius for most of the day. When we came to the top of a small hill there it was on the end of my bonnet. It was gorgeous and quite bright but very nice and extremely exciting to see. —Preceding unsigned comment added by Morrilbro (talk • contribs) 08:36, 27 January 2008 (UTC) _____holly

[edit] Textbook Drawing of Rainbow?

I came to wikipedia:Rainbow, to show my daughter the COLORS of a Rainbow. There are some great pictures, but I was wondering if there is a place for a textbook drawing of a rainbow? Silly as it is, I try to use the colors in order, and would like to teach my kids this also. (or perhaps my question is whether there is a kids.wikipedia.org ?) Pachai (talk) 02:56, 28 February 2008 (UTC)

This is a sensible comment on the content of this article - where else on the net would you look for a rainbow diagram to teach the colours? I've added a diagram here and also to Roy G. Biv. Possibly not in the right place? My last contribution to the page was removed and reading the Talk page, I can see why. Hopefully this will be more useful.
ProfDEH (talk) 09:17, 28 February 2008 (UTC)

Tedridge (talk) 16:39, 28 April 2008 (UTC)

[edit] Strunk and White

The "Religion and mythology" section contained the sentence

In the Biblical canon of Christian and Jewish scripture, the rainbow is explicitly stated as a sign of the Noahic Covenant between God and The Creation, and the biblical God's promise to Noah that never again would The World be purified by the Deluge (Genesis 9.13-15[14]):

It was a prime candidate for the application of the best-known dictum of The Elements of Style: "Omit needless words."

"... Biblical canon ..."

"Bible" works just as well, eliminates the impression that we are headed on a trajectory toward a discussion of what constitutes the canon, and is just flat-out less pompous.

"... of Christian and Jewish scripture ..."

In mathematical terms, this phrase has a one-on-one mapping to the previous one.

  • The Bible, however defined, but certainly the Book of Genesis, is the "Christian and Jewish scripture."
  • It is the only such scripture, as opposed to the Rig Veda, Theogony, or the Elder Edda.
  • It is theirs alone, and not regarded as scripture by others, such as Buddhists or Shintoists.

It's a tautology, and the phrase is redundant.

"... is explicitly stated ..."

Something may be either explicit or implicit. Since, however, the thing is "stated," the default understanding is that it is explicit. The word is, therefore, unnecessary.

"... as ..."

This is a grammatical error. What is wanted is "to be."

"... a sign ..."

Use of the indefinite article indicates that the noun is one of many. As there is only one sign, the definite article, "the," is correct.

"... the Noahic Covenant between God and The Creation, ..."
"... the biblical God's promise to Noah ..."

The two phrases are all but equivalent. This being so, we toss the former (longer) and retain the latter, however noting that on two points, the first was superior.

  • As the sentence begins by limiting the discussion to the Bible, the term "biblical" is superfluous. There is utterly no chance that the reader would possibly conclude that it refers to Quetzalcoatl, Odin, or Amon-Ra.
  • As the quoted passage extends the promise not merely to Noah, but to "every living creature of all flesh," the term "The Creation" in the deleted phrase was more accurate. However, as the issue is the promise itself, it isn't necessary to specify to whom the promise is made. The reader can see that for him- or herself in the immediately following quotation.


"... The World ..."

The capitalization is incorrect, certainly for "The." In any event, the term is wrong as the story does not depict the disintegration of the planet, but the extinction of land life. Therefore, that's what the sentence should say.

"... purified ..."

The author is editorializing. While he may believe that the world would be somehow "purer" if zoologically limited to fish, the text does not reflect this nihilist attitude. The passage merely says "destroyed," without a value-judgment.

"... the Deluge."

We have here the reverse of an earlier infelicity. Use of the definite article refers specifically to Noah's deluge. What is under discussion is any other deluge. What is wanted is the indefinite "a deluge." We can, however, do even better by replacing both words with the simpler "flood."

A later editor appended a "[sic]" to the scriptural quotation "I have set my bow in the clouds, and it shall be a sign of the covenant between me and the earth ..." with the rationale that

"Earth in this context is a proper noun and in true and correct grammatical form should be rendered with the initial letter capitalized."

This is actually somewhat problematic. While the orthographic point may be well-taken, there were three other options available. The fact that the "[sic]" needed an explanatory note, which is not usual for its more routine uses - misspelling, non sequitur, or gross grammatical error - indicates that one of the other choices might be better.

  • Let it go. The standard use of sic is "to indicate that an incorrect or unusual spelling, phrase, punctuation, and/or other preceding quoted material has been reproduced verbatim from the quoted original and is not a transcription error." As the sentence we have been analyzing ends with a direct linked reference to the text, it is somewhat superfluous to cover for the transcriber by noting that the spelling is in the original, when the reader can see it for himself.
  • As the quoted text is merely an (Elizabethan) English translation of the Hebrew original, our editor might have made the correction directly as "Earth," or, more properly, "[E]arth." While this is a questionable tactic, it might be pointed out that Hebrew lacks upper and lower case letters. The translators were on their own when it came to capitalization.
  • The editor might have rooted about for a substitute translation that met his standards. Wikisource provides dozens.

In any event, the editor makes an unwarranted assumption. He takes "the earth" to mean the entire planet. He has ignored the possibility that it merely refers to the land portion (which would not be capitalized). When we consider what "the earth" means in context, it is certain that the latter meaning is correct. Clearly, it is not the inanimate dirt and rocks that comprise the lithosphere that are being promised anything, but the living creatures of the land. This is metonymy, where "the earth" substitutes for "land animals." (Note that sea creatures are unaffected in the Flood story.) So "the earth" in "... the covenant between me and the earth ..." should not be capitalized.

The other use of the term, "When I bring clouds over the earth ...," is somewhat ambivalent. Yet the inclusion of "again" in "the waters shall never again become a flood to destroy all flesh," when "all flesh" is actually limited to land creatures, hints that, again, only the land is meant.

In any event, as the reader is unlikely to assume a repeated miscapitalization on the part of the Wikipedia transcriber, the inserted "[sic]" is, if not a needless word, an unnecessary one. Additionally, for such a minor transgression (if it even is one), swooping in to point it out, appears to be less a mark of self-protection by a transcriber to forestall the reader from blaming him for an orthographic irregularity, but more, if I may be pardoned for saying so, a smug and unpleasant game of "Gotcha!"

I have removed the insertion.

As it stands, the shortened sentence contains an ambiguity that might lead the reader to an oddball belief as to what the scriptural text implies. The text does not support the notion that the Bible posits Genesis 9:13 as the creation of the rainbow. Refraction being inherent in the physics of waves, the earliest point in the biblical chronology for the existance of the rainbow is found in Genesis 1:3-4, although it is not specifically mentioned there.

It depends on how you regard the bible. If you insist that there cannot be any scientific errors in it (on account of it being word-for-word from an omniscient creator), then you must maintain that the creation of the rainbow is not implied. If the bible, however, is simply the creation myths of a certain bronze-age people, then it is quite obvious that the passage is meant to explain where the rainbow comes from, and documents its "inauguration" (for want of a better word). —Preceding unsigned comment added by 210.193.179.135 (talk) 00:11, 27 May 2008 (UTC)

While this issue might be dealt with in a supplimentary sentence, it is well to remember that the article concerns the rainbow, not biblical exegesis, and that this section is merely a minor note on the subject. With that in mind, altering "is stated to be" to "becomes" appears to be sufficient.

As a final note, I wish to defend the prolixity of what appears here. This concerns, after all, just a Minor Edit. Why have I not followed the excellent example of Mr. Finnegan, [7] and merely explained "tightened wording?"

The problem is that dealing with anything even remotely connected with religion is akin to lighting a match in a fuel depot. Someone is liable to have his nose thrown out of joint. It is my forlorn hope that this point-by-point lengthy explanation will forestall any explosions.

B00P (talk) 11:29, 18 May 2008 (UTC)

[edit] Rainbow as an emergent phenomenon

It would be nice to see some expansion on the point that the rainbow emerges from the individual behaviour of raindrops and their interaction with the viewer. It's mentioned, but the point could be expanded. Other similar optical effects include the blueness of the sky, diffraction on a CD. You can see something similar by looking into a box of drinking straws.

Also - because each eye sees its own rainbow, a rainbow always appears at infinity. Much like a heads-up display. —Preceding unsigned comment added by 210.193.179.135 (talk) 00:06, 27 May 2008 (UTC)