Talk:Sunset/Archive 3

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Incident solar white light traveling through the earth's atmosphere is attenuated by scattering and absorption by the air molecules and airborne particles by a combination of Rayleigh scattering and Mie scattering.^[1] At sunset and sunrise, sunlight's path through the atmosphere is much longer than during the daytime, which creates different colors. At sunrise and sunset there is more attenuation and light scattering by air molecules that remove violets, blues and greens, relatively enhancing reds and oranges. Because the shorter wavelength light of violets, blues and greens scatter more strongly by Rayleigh Scattering, violets, blues and greens are removed almost completely from the incident beam, leaving mostly only longer wavelength orange and red hues at sunrise and sunset, which are further scattered by Mie scattering across the horizon to produce intense reds and oranges, when there are soot, dust, or solid or liquid aerosols in the atmosphere.^[2] The removal of the shorter wavelengths of light is due to Rayleigh scattering by air molecules and small particles of sizes an order of magnitude smaller that the wavelength of visible light (typically particles and molecules smaller than 50 nm).^[3][4] The sun is actually white when observed without any air between the viewer and the sun, so, sunlight in outer space contains a mixture of violets, blues, greens, yellows, oranges and reds. Due to Rayleigh scattering, the sun appears reddish or yellowish when we look at it from earth, since the longer wavelengths of reds and yellow light are scattered the least, passing through the air to the viewer, while shorter wavelengths like violet, blue, and green light are effectively removed from direct sunlight by air molecules' Rayleigh scattering.

Rayleigh scattering is the elastic scattering of electromagnetic radiation due to the polarizability of the electron cloud in molecules and particles much smaller than the wavelength of visible light. Rayleigh scattering intensity is fairly omnidirectional and has a strong reciprocal 4th-power wavelength dependency and, thus, the shorter wavelengths of violet and blue light are effected much more than the longer wavelengths of yellow to red light. During the day, this scattering results in the increasingly intense blue color of the sky away from the direct line of sight to the Sun, while during sunrise and sunset, the much longer path length through the atmosphere results in the complete removal of violet, blue and green light from the incident rays, leaving weak intensities of orange to red light.^[5]

After

Sunset colors are typically more brilliant than sunrise colors, because the evening air contains generally more particles and aerosols and clouds than morning air. Cloud droplets are much larger than the wavelength of light; so they scatter all colors equally by Mie scattering, which makes them appear white when illuminated by white sunlight during the daytime. The clouds glow orange and red due to Mie scattering during a sunset because they are illuminated with the orange and red light that remains after multiple prior Rayleigh scattering events of the light from the setting sun. </ref> ^{[2][8][5] [1]}

Ash from volcanic eruptions, trapped within the troposphere, tends to mute sunset and sunrise colors, while volcanic ejecta that is instead lofted into the stratosphere (as thin clouds of tiny sulfuric acid droplets), can yield beautiful post-sunset colors called afterglows and and pre-sunrise glows. A number of eruptions, including those of Mount Pinatubo in 1991 and Krakatoa in 1883, have produced sufficiently high stratospheric sulfuric acid clouds to yield remarkable sunset afterglows (and pre-sunrise glows) around the world. The high altitude clouds serve to reflect strongly-reddened sunlight still striking the stratosphere after sunset, down to the surface.

Sometimes just before sunrise or after sunset a green flash can be seen.^[9] - I offer the most recent version, because I do not know how to undo Alvegaspar's continued un-justified changes, and I would like a version saved here for future use - including both useful fotos.The Good Doctor Fry (talk) 18:51, 18 December 2010 (UTC)

I have removed the photo and caption purporting to show a sunset formed by Rayleigh scattering alone (no Mie scattering). The point the editor was trying to make: The sky lights up red only when there are clouds (or other particles) to reflect the reddened sunlight. While true, I (and others who have deleted the photo before) don't think it warrants the space. Spiel496 (talk) 23:55, 25 December 2010 (UTC)

Sentences about the wavelength-dependence of Rayleigh and Mie scattering I moved earlier in the section so that it gets to the point sooner. Then in this pair of edits I deleted everything that was either redundant or not specifically about sunrises/sunsets. Although I have removed a sizable chunk of prose, I assure you that my intention was to preserve all the important points. If there is now something missing from the explanation of sunset colors, please don't hesitate to call me on it. Also, the references are probably displaced from their content, but that can get fixed later. Spiel496 (talk) 00:28, 27 December 2010 (UTC)

• I agree with the changes. However there is no need for such an abundance of references; this is not a scientific paper. May I suggest the same cleansing process for Sunrise? Alvesgaspar (talk) 11:21, 27 December 2010 (UTC)

Spiel's edits make a shorter but a bit less precise article. This new version describes the actual sequence of events, and includes the key references. These references cover different materials, which makes each of them necessary to cover the essentials. There were some minor factual errors that I corrected, particularly the repeated imprecise and inaccurate use of "wavelenghts" in place of "light" or "wavelengths of light". "Light" refers to visible light in this article, which is what Rayleigh and Mie Scattering and sunsets and sunrises are about, while "wavelength" is a generic term used to describe general EMF - including X-Rays, Gamma Rays, Microwaves, Radio Waves etc - all of which have nothing to do with this article. All seems good now.The Good Doctor Fry (talk) 04:41, 29 December 2010 (UTC)The Good Doctor Fry (talk) 05:35, 29 December 2010 (UTC)

from the beams that reach the viewer: this phrase has been inserted as a clarification. I thought it was obvious that the light we're talking about is that which reaches an observer. But when met with discussions of incident, scattered and transmitted components, the reader could get confused, I suppose. However, it cannot be necessary to include this phrase twice in consecutive sentences. We must be able to refer to a term like "the light" without repeating every prepositional phrase used to define it. The section will just get too long otherwise, and the longer it is, the less likely the reader is going to get the point.

A related topic: "attenuated" and "removed". These were not meant to imply absorption. Do they imply that to the general reader? I wouldn't have thought so, but in the edit summary here Fry implies that there is confusion. Is there a way to make it clear up front without the wordy phrase by scattering them out in all directions? Would it help to remove mention of absorption in the first sentence (it isn't mentioned later on anyway)? Spiel496 (talk) 15:43, 31 December 2010 (UTC)

The "by scattering them out in all directions" may seem wordy, but it is necessary to give an accurate description. Without the diagrams that show the scattering in all directions, it is natural for readers to make the common error to think that the light has been absorbed or removed, particularly when these misleading and incorrect/incomplete terms of "removed" and "attenuated" and "absorption" are used in concert to point the reader into incorrect directions of thinking about how the amount of light that reaches the viewer is actually reduced. The current explanations lead back to the old incorrect thinking that the light is absorbed vs being scattered. Unless we edit out the absorption and removal and attenuation terminology, and only talk in terms of scattering in all directions, with consecutive net scattering of light to the viewer, I think the only other good alternative is to further dumb down the language, while also including the two scattering diagrams (pictures) shown above, that other non-scientists kept removing in some artificial process to shorten the article. Shortening things solely for brevity's sake is not desirable nor is it accurate in this case. I would be glad to rework the diagrams (shown in blue above) to eliminate the "Trial Copy by Smart Draw" logos... These diagrams show more details than any of the other 7 versions of Rayleigh Scattering, I could find on the web, and they are are the only ones showing the color shifting that reaches the viewer, and they are technically accurate. Your thoughts?189.148.46.232 (talk) 02:10, 3 January 2011 (UTC)

The concern is that the reader will interpret "removed" and "attenuated" to mean "absorbed". If there is really a chance someone is going to think absorption is the cause of sunset colors, then I agree we should remove the word from the first sentence. And if there is a chance the reader will fail to understand that we're talking about light heading towards an observer (although, frankly, what else would make sense?) we should make the first sentence be about that ray of light. I propose: As a ray of sunlight travels through the atmosphere to an observer, some of the light is scattered out of the beam by air molecules and airborne particles. (Yes, this is not the whole truth, because light is also absorbed and hits birds etc., but scattering is the point we're trying to make.) Then the second sentence can relate the blue-scatters-more to the observation of less-blue-from-the-sun, without the need to bring up scattering or where the light is going. The third sentence can then bring it home by relating the long path length to the complete loss/attenuation/removal/whatever of blue light. I don't think this new version of the first sentence harms the article, so I'm going to make that change unless someone raises a quick, valid objection.

Regarding the diagrams, my concerns are

1. There are two diagrams. No way does the article need two.
2. The first diagram (sunlight coming in at an angle) doesn't make sense to me. The picture implies (wrongly) that yellow light comes from the direction of the sun, but red light comes off the large particle.
3. The second diagram (horizontal sunlight beam): The ray of light incident on the cloud leaves the last air-scattering event at an angle, making it look scattered rather than transmitted. It really should be the last transmitted ray from a parallel series of air scattering events. But to draw that would make the diagram too cluttered, so I don't know.
4. The diagrams contain words. A picture is supposed to worth a thousand words, not be a vehicle to add more words.

Spiel496 (talk) 18:20, 3 January 2011 (UTC)

Spiel, all excellent proposals.

Can we add "white", then "wavelengths are" or "colors are" and at the end "changing the color of the beam" to the sentence: As a ray of white sunlight travels through the atmosphere to an observer, some of the colors are scattered out of the beam by air molecules and airborne particles, changing the final color of the beam the viewer sees.  ?

Your sentence captures the reason for this section: colors, and it gives an accurate partial explanation of the shift from white sunlight (where most people think the sun and sunlight are yellow/orange), to what we actually see = mainly yellow light during the day time, with enough red to make the sun look orange to some people - depending on the person's red-light sensitivity (important since most men have diminished red-green visual sensitivity, compared to women). The proposals on sentences 2 and 3 seem dandy and too the point - backfilling the missing details from a strong general opening sentence.

1. 1 diagram would seem preferable for a sunset-sunrise color description. I proposed 2 during a time in the ongoing discussion where some contributors did not seem to understand the sequence of events that lead to a typical well-colored sunrise/sunset.
2. Yellow light in the ray (remaining after blue has been depleted by successive Rayleigh Scattering events), does come through to the viewer, along with red - but I highlighted yellow, since that's what most people see (accounting for the slight red-green color blindness of most men), and showed the red scattering off a particle in the daytime diagram as a set-up for the 2'nd diagram of sunset events. If we have only one diagram, then your observation makes better sense. For me, there are so many different scattering and transmission events taking place, no Wiki format single diagram can capture all of them.
3. The last scattering is supposed to demonstrate a cloud or large particulate (soot) or aerosol off axis scattering that gives red colors higher off the horizon.
4. I like the fundamental issue of the point of a picture, but I also noted how many other web articles have copied your and my past writings and descriptions from this page - which means I thought a diagram with text boxes would be lifted out to help other people's explanations, where the people copying our previous stuff onto other sites tended to lift only part of the text.

Do these observations fit your understandings? what next? (make a fresh diagram? w/ no text?)

The Good Doctor Fry (talk) 00:26, 4 January 2011 (UTC)

I'm O.K. with the proposed wording As a ray of white sunlight travels .... Regarding the diagram, I think the reddening of the sunlight should be done with just one "thing" not three. Any point you may be trying to make about those three separate scattering events is not coming across. Maybe just have a beam gradually becoming redder and redder as blue scatters off of it along the whole length. And the cloud, if not omitted completely, should be lit by an off-set, parallel, reddened beam from the sun. Having the cloud illumination sneak out of the beam that was heading to the observer is just confusing. Spiel496 (talk) 20:31, 4 January 2011 (UTC)

In Item 2 above, another point for showing the yellow, is to confirm what most people perceive = a yellow sun, while a spectrometer sees a different picture. Humans' vision sensitivity dramatically peaks in the center of the visible spectrum, having the most sensitivity for green, and the sensitivity falls off when you move away from green. ROYGBIV - shows that Red & Violet are furthest from Green and Blue & Violet are closest to Green, which explains why the sky appears blue (not violet) and the sun appear yellow (not red) - where a color-neutral spectrometer sees a violet-blue (Indigo) sky and a reddish-yellow (Orange) sun during the daytime. The sun only appears red when the yellow has been removed by successive Rayleigh scattering events - during the long path-length times of sunset and sunrise.

This is the reason I show yellow passing forward, mostly un-scattered when compared to blue's and violet's heavy Rayleigh scattering. As described above, I don't think it's possible to make a Wiki-acceptable diagram that shows all of what's going on: The diagrams are also incomplete in that they don't show whats happening for Orange, Green, Indigo, &nd Violet = colors that are as equally prominent in reality/spectrometry, but these colors seem to be less important to most human's thinking.

I personally prefer a detailed description because human minds tend to fill in the blanks (often incorrectly) when you don't specifically spell out the facts: how many readers realize that Greens are scattered just enough from a human viewed sunbeam, so that the sun does not look green, but Green is not scattered enough for the sky to look Green - a fun balance, especially when you recall human's heavily green-biased vision. I took a shot at these sorts of more-factual descriptions in the previous version (still available over under sunrise), including the equally important violet and green colors in the description, but non-scientists have consistently deleted and edited these much more accurate descriptions, because these types of descriptions don't fit classical physic's texts' narrow descriptions nor do they fit the oversimplified models that non-scientists prefer: Red/Blue only explanations of sky, sun, clouds, and sunrise and sunset - no aerosols, no droplets, no math, no Green, no Violet, etc.

Spectrometers, Bugs and many other creatures with less-color-biased vision see a violet sky and a red sun => much closer to reality. Since modestly educated humans are the typical consumers of this article, does it makes sense to give the customer what they want: no math, no descriptions of the dramatic 10(exp-4) and 10(exp-6) relationships, simplified diagram (s) of what happens to shift the net color the viewer sees, mininal descriptions of the actual details and facts, and sufficient references for interested people to be able to go read the real details in other locations? Is Wiki's goal to give people what they expect? Pretty colors and text that has its fact heavily pared-down to meet non-scientist editor's tastes?

Can Wikipedia instead play the additional role to educate in ways that go beyond typical physics texts' limited and occasionally incorrect descriptions (i.e they ignore Mie Scattering and substitute incorrect absoprtion/absorbance/transmittance/refraction ideas)? I personally can live with a pared-down version, but I think that choice cheats bright 12 - 18 year olds out of a chance of learning what's actually going on. I would have loved to have the complete picture when I was 12 or 13. Instead, almost all young people get inaccurate descriptions that use factually incorrect: refraction, absorbance, absorption, attenuation, prism-based explanations that contaminate their thinking for decades, and many of those young people go on to be science and physics teachers who continue to teach the faulty explanations (especially refraction-based explanations that oversimplify the scattering events to Red/Blue Rayleigh-only descriptions - witness the last 3 years of conversations that occurred to get to this current more accurate point in this article).

Redaction: Wikipedia could actually do a better job than any single one of the quoted texts, by blending the information from multiple sources and spectrometry experts. Redaction is a highly honored skill in the rest of the intellectual world, could it also be so in this article - even though it causes some people to stretch their thinking beyond their previous limited state(s)?

Along these lines, is it worth a token mention of the human-biased color perception skewing of what is actually present vs. what we see/perceive with a reference to the bias inherent in human's color vision? (to direct interested readers to the rest of the story?) I just checked, and Wiki already has a section describing the heavy green-bias of color vision, (easy to provide a reference that satisfies Wiki-oriented editors). Is it also appropriate to give Yellow, Green & Violet and aerosols at least token mention in the article - even though they are equally scientifically important, yet excluded from the editors' favored references?

I'm a fan of feeding interested and engaged intellects, tossing out tasty details, in ways that people can either ignore or gobble-up.

Just what is Wiki all about? Satisfying the pecadillos of individual Wiki-editors? * Pretty colors and highly-simplified explanations that fit some reader's preconceptions? * Sating a wide variety of readers? * Educating readers? * Providing easy fast ready-references? * Redaction to create accurate accessible enlightening articles?

189.148.46.232 (talk) 15:00, 4 January 2011 (UTC)189.148.46.232 (talk) 15:02, 4 January 2011 (UTC)

---

Wow. I really like the edits that Spiel has made. Crisp, accessible, factual, and well documented with good references.

Well done.

Should we do the same with the sunrise article, replacing the current text with this text - with tweaks to make it fit sunrise vs. sunset? And is a diagram needed? The Good Doctor Fry (talk) 06:18, 5 January 2011 (UTC)

Here are versions of the diagrams using edits proposed by others above, showing both Rayleigh and Mie Scattering events that give a yellow & red sun, blue sky, and red and orange sunset colors, with the "Smart Draw Trial Edition" removed. The Good Doctor Fry (talk) 02:59, 3 January 2011 (UTC) . . 189.148.46.232 (talk) 03:28, 3 January 2011 (UTC)189.148.46.232 (talk) 03:56, 3 January 2011 (UTC)

• Once again, images are being forced into the article. Please see this edit: [16]. I called the attention to the discussion that took place some time ago (here) but with no apparent success. Please someone help as I don't want to start an edit war. Alvesgaspar (talk) 10:05, 27 December 2011 (UTC)

• By deleting the variety of Sunsets that have been previously posted on that page, it's ended up a RED page. There is every single color in the spectum at sunset during a variety of Atmospheric conditions. That is the main void on that page. Also, when a reader finds himself on the Sunset page, it is with the anticipation of seeing the most stunning photos of Sunsets that Wiki has in it's valt. Where are they? My suggestion would be a Gallery section at the bottom of the page where an editor would be allowed to choose only 1 Sunset photo from his favorites to display if he is so inclined. This will solve all the issues you guys seem to be having with this section, and also leave it up to the READER to decide what is beautiful and what is boring. Because in my opinion......that page is a Giant Red Bore. Here is an example of some of the colors that show up at Sunset with the right conditions. I'm not suggesting we use these photos or any of my sunset photos, but let's put some color on that page. Pocketthis (talk) 21:23, 27 December 2011 (UTC)

• Yes, I agree that there is space in the article to accommodate other pictures of high quality, depicting different types of sunset. However Wikipedia is an encyclopaedia, not a social forum or a showcase of popular images. Pictures should be chosen strickly in accordance with their illustrative potential and image quality, not decorative value. If people want to see gorgeous photos of sunset of all kinds they can visit Commons gallery here. Alvesgaspar (talk) 21:46, 27 December 2011 (UTC)

• What did anything I said, in any way infer that Wiki should be a Social Forum or a Showcase of Popular images?

I'm done with the subject. Happy New Year to all. Pocketthis (talk) 01:33, 28 December 2011 (UTC)

Today, I added some text about the fact that, at sunset, the solar disk is distorted by refraction. I found an image in Commons that shows the effect, and put it in the article alongside my text. In order not to increase the number of images in the article, which some people seem to find excessive, I deleted another one that did not seem to me to contribute anything. I thought this was a reasonable compromise.

But no. Alvesgaspar has seen fit to delete the picture, saying it is of "poor quality". Certainly, it is not very spectacular, but it shows a sufficiently large image of the sun's disk for its non-circularity to be evident. That was the purpose of putting the image in the article, and it served this purpose well. I could not find any other image in Commons that was as good. Without the image, the text still describes the effect, but with reduced clarity.

I think the image should be put back. I'd do it myself, but that kind of tit-for-tat gets silly. Alvesgaspar should do it.

DOwenWilliams (talk) 03:22, 13 August 2012 (UTC)

Today, Alvesgaspar has re-introduced the image I deleted from the article. It shows sunset near San Francisco, and is certainly pretty (though not as pretty as another image further down), but it adds absolutely nothing to the informative nature of the article. The image I put in, and he deleted and has not restored, clearly showed something of which many readers may not be aware, that the apparent shape of the Sun when it is close to the horizon is not circular. It is "squashed", so it is wider than it is high.

I suppose this raises a basic question about the function of images in Wikipedia articles. Are they intended to inform, illustrating and adding to the text, or are they intended just as pleasant decorations? Both functions are valid, but which should take priority? Clearly, Alvesgaspar and I have different opinions about this.

What do other people think?

DOwenWilliams (talk) 14:33, 13 August 2012 (UTC)

• • • Welcome to the 'Sunset according to Alvesgaspar' Fan Club. He runs a tight ship here, and we respect his technical photo expertise and seniority. All photos on the Sunset page need to come here first for approval; before they are placed in the Sunset Article. It's a "Sunset" unwritten Law that I have learned the hard way...lol. Speaking of new Sunset photos, I have placed a new candidate on the bottom of the page. I think it's relevant and uniquely colorful. You may also place your candidate there as well, and let's see what you are referring to. Thanks

Pocketthis (talk) 18:33, 16 August 2012 (UTC)

• • Took a look at the San Francisco photo up there now. You are 100% correct. It is a "Twilight" photo, and should be removed from the Sunset Article. In fact two of the four technically very nice photos that are displayed on the Sunset page are Twilight photos. What our technical consultant, the aforementioned Alvesgaspar refuses to take into account, is the fact that sometimes a photograph is only as "technically perfect" as the Artist wants it to be. Grain, shadows and reflections can enhance an otherwise technically perfect shot. A technically perfect shot of "nothing of interest", is still "nothing of interest". If we are looking for an elongated filler that is actually Sunset, and even shows the widened Sun, perhaps we should use this one in that spot. I'll wait 30 days for arguments against the change. If there are non, I'll exchange it.

Pocketthis (talk) 18:58, 16 August 2012 (UTC)

This is the image that I put in, and Alvesgaspar deleted. It shows the Sun just about to set (seen from Dubai), obviously distorted by refraction. It was the best image I could find in Commons to show the shape-distortion effect. In most others, the shape of the Sun is difficult to see because of glare, or because the image is too small. DOwenWilliams (talk) 20:08, 18 August 2012 (UTC)

• I saw that image in Commons as well; and didn't choose it because it isn't Sunset. Also....it's another Red Photo. We've got to show some variety in colors. That said.... It's certainly more relevant than the Twilight photo that's up there now. If you blow up the photo I posted, you can see the Sun quite clearly; the colors are unique, and you can't argue about what time of day it is. Thanks Pocketthis (talk) 22:48, 18 August 2012 (UTC)

Do you mean the image just above, to the left? To me, it shows the Sun's shape very poorly. Sure, it has some pretty colours, but how important is that? (I'm somewhat colour-blind. I see blue poorly. So colours are probably less important to me than to many other people.)

Does this have to be an either/or thing? Why not include pictures that show varieties of colours and ones such as the one I am recommending that clearly illustrates a point that is made in the text of the article?

DOwenWilliams (talk) 03:50, 19 August 2012 (UTC)

• • • Hello again DOwen, It certainly doesn't have to be an either/or thing at all. Who knows who will make what suggestion about a photo they have found somewhere; or the entire idea can be voted out in the next 30 days. I will tell you this much from experience: This is the hardest Article to get a new photo to stick in for more than a few days. The folks here have decided to make the scientific text description of a Sunset "King" here. If it were up to most involved in this article, there wouldn't even be a photo :). Kind of odd don't you think? This is the one place on the entire site that screams for more photos just with it's name: Sunset. On the flip side of the coin, everyone and their mother-in-law has a favorite Sunset photo they'd like to post; so I can understand the strict rules here. If nothing comes from this discussion in the next few weeks, I'm going to start a Galley at the bottom of the page; and put up the best shots from Commons on it. I think that will be an easy thing to control, and will add some beauty to the page. As far as your comment about my photo showing the Sun's shape poorly....It's how the Sun looks at Sunset to the Human eye if someone were to be wearing sunglasses. That's what I used as a Sun filter for that shot. It was reality and timing I was trying to accomplish; and I got both I think; plus some coloring the page needs. Thanks. Pocketthis (talk) 15:05, 19 August 2012 (UTC)

Maybe we should just put in this link to the Commons sunset collection. It has about 500 images of sunsets, I think.

http://commons.wikimedia.org/wiki/Sunset

Yes. I agree that the situation here is "kind of odd". A picture is said to be worth a thousand words, and yet those "in charge" here seem to want no pictures, only words.

Oh well... In the grand scheme of things, it's not important. Most academics are contemptuous of Wikipedia, anyway.

DOwenWilliams (talk) 19:04, 19 August 2012 (UTC)

P.S. I just put that link into the article. Let's see what happens to it! DOwenWilliams (talk) 19:23, 19 August 2012 (UTC)

• • Well...When the day finally arrives that unregistered users like Ma and Pa Kettle can't edit Wiki, things will improve. Having everyone in the world able to edit here was a great idea in the beginning; however, it's grown so large, registered users with some credentials will be the Wiki of the future I'm sure. In the meantime users like you and I and countless others genuinely concerned about what is displayed here will have keep an active eye. The link was a good idea. Alvesgaspar always reminds us that if folks want to see pretty Sunsets, they can always go to Commons. The problem with that is, the average user doesn't even know that Commons exists. And remember......there's no one in charge here; there's only those that have agreed to submit to the talk page before posting new photos. Thanks. Pocketthis (talk) 00:07, 20 August 2012 (UTC)

The article contains the common misconception that public schools still teach to this day, that Copernicus discovered the earth revolves around the sun. The

The section has been reworded to address these issues. Piperh (talk) 04:01, 4 August 2012 (UTC)

Considering that this page is within the scope of the 'Time project', the definition of sunset time should be more precise.

A definition in wide use is: the time, when the upper limb of the apparent image of the sun passes the astronomical horizon. Since you want to calculate the times these definitions have to be unambigious. No problem with the astronomical horizon, but where the apparent image of the sun is located, is based on the refraction of a standard atmosphere. A standard value for the refraction angle is 0°34′.

The apparent time of sunset may differ widely from this. Some of the reasons (mainly the viewers elevation) are explained here: http://www.ikth.dk/almanak/kiming_refraktion/kim_refr.php
The actual refraction depends on location, humidity, pressure and temperature.

Valmuevej (talk) 16:15, 27 February 2013 (UTC)

The caption on the first photo appears to be incorrect, due to the effect described in the first para of the article. Isn't the position shown actually after astronomical sunset, and about a minute before apparent astronomical sunset? SeanLegassick (talk) 15:04, 9 January 2011 (UTC)

• Agree. Alvesgaspar (talk) 17:17, 9 January 2011 (UTC)

I can't find a definition of the phrase "apparent astronomical sunset". (Almost all google hits have lifted the entire sentence from this very article.) I suspect the intent was to mean the same thing as just "astronomical sunset", which is defined as the time when the upper edge of the disk is on the horizon [17]. Spiel496 (talk) 00:05, 10 January 2011 (UTC)

OK, having read that source I agree that "apparent astronomical sunset" seems to be redundant. I've edited out both occurrences of "apparent" accordingly SeanLegassick (talk) 11:51, 10 January 2011 (UTC)

This still seems to be wrong. I think you may want to say "actual" sunset instead of "astronomical" sunset. Astronomical sunset can be confused with astronomical twilight which occurs when the sun is 18 degrees below the horizon. Since the sun is about a half degree across that is happening around 36 sun disks below the horizon. Is there really a term, "astronomical sunset"? Is it when the last limb of the sun dissapears below the horizon as if there was no atmosphere? Isn't that "actual" sunset? The whole first paragraph has some mostly right but not quite right things to it. Read sunrise which has included a good explanation of astronomical, nautical, and civil dawn which is just the reverse of dusk. MBCF (talk) 21:45, 31 January 2011 (UTC)

There's a lot of confusion here - and lack of precise definitions. Maybe this link to my humble website 'Almanak' could clarify some things: http://www.ikth.dk/almanak/kiming_refraktion/kim_refr.php Valmuevej (talk) 13:20, 27 February 2013 (UTC)

The statement "Sunsets occur precisely due west on the equinoxes for all viewers on Earth" is not quite accurate. Because an equinox is an instant in time, the sunset will only be precisely due west at the one longitude on earth each year where the instant of sunset happens to coincide with the instant of the equinox. At other locations, the sunset will occur very close to due west on the date of the equinox, but not precisely. Although the tiny difference is unlikely to have practical consequences, the sentence has been reworded in the interest of theoretical accuracy. Piperh (talk) 04:15, 4 August 2012 (UTC)

Also, because of atmospheric refraction and the Sun's non-zero size, the upper edge of its disk may cross the horizon at a significantly different time than that when the centre of the disk is geometrically on the horizon. If the Sun is descending at a shallow angle, as seen from high latitudes, its azimuth may change by tens of degrees during this interval. DOwenWilliams (talk) 14:03, 4 August 2012 (UTC)

There should be a section on the meaning and symbolism of sunrise and sunset in various cultures. For instance, various graves and barrows in Britain and Ireland are aligned with the sunrise (more so than sunset- which is also interesting). I'm also sure that in various mythologies there are gods linked with these events. And finally, we call Japan - 'land of the rising sun', and there's that song

I would like to suggest this photo for filling the free space under photo#1. It's pretty Spot on, and the colors will enhance the boring red page. Thanks, Pocketthis (talk) 18:19, 16 August 2012 (UTC)

Hello! This is a note to let the editors of this article know that File:Sunset 2007-1.jpg will be appearing as picture of the day on April 13, 2013. You can view and edit the POTD blurb at Template:POTD/2013-04-13. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks! — Crisco 1492 (talk) 23:10, 27 March 2013 (UTC)

Picture of the day

Sunset is the daily disappearance of the Sun below the western horizon, and often results in an intense orange and red coloration of the Sun and the surrounding sky. Locations north of the Arctic Circle and south of the Antarctic Circle experience no sunset or sunrise on at least one day of the year.Photo: Alvesgaspar

Archive – More featured pictures...

The 1st para says sunset occurs when the azimuth is greater than 180 degrees. Following the link to Azimuth (see https://en.wikipedia.org/wiki/Azimuth), it seems like an azimuth of 180 degrees is South and an azimuth more than 180 degrees means South through West to North.

Seems more like Sunset is when the Altitude is less than zero instead (again, going by the diagram in the Azimuth page). — Preceding unsigned comment added by Wikibls (talk • contribs) 09:44, 14 July 2013 (UTC)

The first paragraph does NOT say "sunset occurs when the azimuth is greater than 180 degrees". It says that when the sun sets, it's azimuth is greater than 180 degrees. In other words, it sets in the west. I don't see any need to change the wording. Spiel496 (talk) 17:00, 14 July 2013 (UTC)

I wrote that wording. I still think it is accurate. The sun sets on the western half of the horizon. It may be due west, azimuth 270 degrees, or it may be just to the west of south, azimuth 185 degrees, say, or it may be just to the west of north, e.g. azimuth 355 degees. The azimuth is always greater than 180 degrees (and less than 360). Conversely, sunrise happens on the eastern half of the horizon, with azimuth less than 180 degrees. DOwenWilliams (talk) 19:26, 14 July 2013 (UTC)

All the pictures left in the article look exactly the same. Same yellow-orange same dark hour, same everything. Could be the same picture only different sizes. Sunset doesn't look like this all the time. Hafspajen (talk) 22:17, 28 October 2013 (UTC)

User Pyrometer exclude link to http://sunsetsunrisetime.com on 23:52, 19 January 2014‎ with comment "Bad site: incorrect calculations"

I compare results of 4 sites:

• astroid.eu
• spectralcalc.com
• sunrisehour.com
• sunsetsunrisetime.com

for Tbilisi, Georgia, lat 41.694110 lon 44.833680, timezone GMT+5, 23.01.2014

All resulsts are little different. It is a computational error. I think it is not correct to exclude one of this sites. — Preceding unsigned comment added by 82.151.111.197 (talk) 13:51, 23 January 2014 (UTC)

Alvesgaspar, you simply won't let anyone edit this article, right? the only pictures in this article are chosen by...well ... Alvesgaspar!

In spite of a real big amout of editors who would like to add pictures to this article. Like foe example Pocketthis who would like to suggest this photo (File:Mustard Blue Sunset.jpg ) the colors will enhance the boring red page.

SajjadF trying to add a picture, and it is constantly removed [18] and [19]. And myself, also stating that All the pictures left in the article look exactly the same. Same yellow-orange same dark hour, same everything. Could be the same picture only different sizes. Sunset doesn't look like this all the time. No answer on the comment on the Talk:Sunset, just more pictures removed. By Alvesgaspar.

DOwenWilliams said :Today, I added some text about the fact that, at sunset, the solar disk is distorted by refraction. But no. Alvesgaspar has seen fit to delete the picture, saying it is of "poor quality". DOwenWilliams (talk) 03:22, 13 August 2012 (UTC) and other problems. [20]

Editor Jsnaturephotos add picture, [21], removed by Alvesgaspar - [22]

Editor Ip ads [23] but is removed by Alvesgaspar - [24].

Arctic Kangaroo adds picture [25], but it is removed by Alvesgaspar [26].

Editor Jmencisom add picture, [27], but it is removed by Alvesgaspar [28]

Others may have the same problem, like Pocketthis : Here is an example of some of the colors that show up at Sunset with the right conditions. I'm not suggesting we use these photos or any of my sunset photos, but let's put some color on that page. Pocketthis (talk) 21:23, 27 December 2011 (UTC) Many editors suggested that the article looks sordid and unpleasant with only one kind of orange - black pictures.

Editor Elph adds a picture [29] and Alvesgaspar removes it [30] with the comment : no need for pictures in every part of the world.

Editor Vhorvat adds a picture [31] and Alvesgaspar removes it Alvesgaspar also removes sourced material. [32]

Added by Fir0002 [33] [34] Alvesgaspar removes it [35]

I do not agree that the pictures removed are bad or poor quality. Neither do others, like [36] Pocketthis.

All this points to a non consensus solution using pictures in this article, using only the pictures chosen by Alvesgaspar.

Hafspajen (talk) 11:57, 5 November 2013 (UTC)

• 
  Archive 3 images This is the image that I put in, and Alvesgaspar deleted, stated by DOwenWilliams.
• 
  Archive 3 images, not used or removed by Alvesgaspar[1] from article
• 
  Archive 3 images, not used or deleted from article
• 
  Archive 3 images, not used or removed by Alvesgaspar[2] from article
• 
  Fishermen under the sunset in Payallar, Alanya removed by Alvesgaspar[3]
• 
  removed by Alvesgaspar - [4]
• 
  View of the famous Manila Bay Sunset from the Bay City in Pasay (near Mall of Asia)...is removed by Alvesgaspar - [5]
• 
  Sunset in Brela, Croatia. Added, [6], removed - Alvesgaspar removes it [7]
• 
  Typical sunset in

  Swifts Creek, Victoria]] added [8] removed - by Alvesgaspar [9]
• 
  not used or deleted from article
• 
  not used or deleted from article

• Info -- Regular users change, people like to see his own images on the article ... and memory is short. No one to blame really! But please take a look at this long thread, where the problem of what pictures should be depicted in the article was discussed: Talk:Sunset/Archive 2. In there you will find more than a couple of images much better than the ones inserted recently in the article. Maybe the discussion can be refreshed with new and exciting material? Fine with me! But the purpose of article is not to host all types of sunsets, taken in the various parts of the world. For that, we have Commons.-- Alvesgaspar (talk) 19:27, 5 November 2013 (UTC)

• I agree with Hafspajen. Yes at the end of the day, you cannot put all pictures but don't give a lame excuse like, "poor quality". Some of the photos on the page currently aren't of a high quality either.

And don't say regular "users". It is "editors". The people who have contributed to this article have good experience in editing articles, They are not noobs. Calling them users is inappropriate. Having the same photos always makes no point. Choose some new photos to make the page more interesting. Photos from different places would increase diversity showing that wikipedia is not biased. And, Yes, some photos look similar because generally the colors during sunset are the same !! A discussion should be made again inorder to pick the best photos. SajjadF (talk) 20:00, 5 November 2013 (UTC)

• • I bumped into this conversation this morning. After I was done laughing about the title of the discussion, I went into the article for the first time in years, and was surprised to see what a mess it was. So I removed the "line-up" from the right side of page and added them to a Gallery setting for diversity. Then I lined up the Mars photo where it belongs next to Planets. Pocketthis (talk) 17:17, 26 March 2014 (UTC)

• As usual Alvesgaspar removed my edits, and in doing so, removed the photos that were put up by others before I moved them to a Gallery. I do feel like some of the photos were more of the Twilight variety, and planned on moving in exchange photos from Commons. However "The world according to Alvesgaspar" should really be addressed here, and rectified. I stopped editing here a couple of years ago because of this man's relentless ego and self appointed guardianship of this article. Good luck Sunrise & Sunset.Pocketthis (talk) 15:00, 27 March 2014 (UTC)

• • Many of us have "pet articles", which we have edited a lot and which we try to keep in good order. I have three or four of them. When I see that someone else has edited one of these articles, I always check to see what they have done. Sometimes, I revert the edit. Sometimes, I make additional corrections or changes. Most often, I leave them alone, accepting that they improve the article, or at least do it no harm. There's no accounting for taste, and if someone thinks some wording should be changed in some trivial way, I'm not going to quarrel with them without good reason. Occasionally, if someone has made a particularly constructive edit, I thank them for it. Constructive editing should be encouraged. But Alvesgaspar has a different attitude. When anyone edits any of "his" articles, he invariably reverts what has been done, without giving any reason except that the edit (usually the addition of an image) is of "poor quality', whatever that means. He does not appear to use any objective criterion. It's just a knee-jerk reaction, which is very discouraging and annoying. I have given up on trying to improve any of "his" articles, which, of course, is just what he wants. DOwenWilliams (talk) 15:45, 27 March 2014 (UTC)

• I recently replaced the photo: Knysnasunset.jpg, that was only receiving Apox: 150 views per month in Commons, with the photo: Burning Yellow Sunset.jpg, that was receiving upwards of 270 views per month in Commons. Alvesgaspar has reversed me, and had some of his old friends come to his rescue by reversing me, as well as coming to my talk page and threatening me. I intend on holding strong here on solid ground. I made a logical edit that improves the boring red colors on the page, while proving its quality by posting the hits it gets in Commons. The average photo in commons gets around 20 hits a month. Both of the photos in question are far above average. The issue here is the fact that Alvesgaspar is positive that he owns this article. As anyone can read here on this talk page, the community consensus has spoken, and any reversal of my edit by Alvesgaspar or any of his long time friends, will be considered an "Edit War".→Pocketthis (talk) 18:38, 19 November 2014 (UTC)

• This kind of ad hominem attacks and accusations is improper of civilized editors and detrimental to the project. I respectfully suggest Pocketthis to withdraw those comments and apologize before the present issue is discussed. I also ask some uninvolved editor (an admin would be better) to roll back the article to before the picture replacement, that is, to 03:45 13 November. Alvesgaspar (talk) 20:28, 19 November 2014 (UTC)

• • I only stated facts. There is nothing to apologize for. If anyone should be apologizing, it should be you for the "hijacking" of this article for many years. The consensus of editors on this page has already spoken. We are relieving you of Command of this article. This article will be edited as any other article is edited, just like I edited it, and many others have attempted to until your reversals. If an Admin were to become involved, you would have to explain to him why you reversed my edit. NOT that it should be reverted to your version until settled. You will eventually end this conversation like you always do, claiming that "if we want to see Sunset photos.....that's what Commons is for". However, you are mistaken. Commons is the depository of uploaded photos where "we get the photos from to post in articles". The community has spoken here here already, and even though the outcome isn't what you'd like......it is what it is.→Pocketthis (talk) 20:59, 19 November 2014 (UTC)

• I wanted to add that I'm sorry that it had to get to this point. We have tried to reason with Alvesgaspar for at least as long as I've been an editor here, (Aug,2011), and for much longer than that when I would just visit this page as a reader. I try not to allow myself to think that it is ego driving Alvesgaspar, but rather a very technically educated photographer, whom has the idea that a technically perfect photo is more important than a sufficiently technical photo, even if the prior doesn't enhance the articles as well as the latter. He has been "deaf earing" the requests from other editors to put some variety on this page for so long, it has become increasingly easier for him to revert and ignore other editors every year. Sooner or later this day would eventually arrive. The day when an editor standing on firm ground tries to end the ownership of this article by Alvesgaspar. I waited for someone else to do it. Others have certainly tried right here on this page. I hope when the dust clears we can all learn to work together here, the way this place was designed to function. I harbor no ill feelings. I just want this page and the Sunrise page as well, to be edited fairly, correctly, and for the benefit of the readers, and not a photographer, science editor, or any other one individual.→ Pocketthis (talk) 21:26, 20 November 2014 (UTC)

Over the past 3 weeks there has been discussion between other editors and myself on our talk pages, about adding a small gallery. I finally got around to making one today. Anyone who doesn't like my choices, and wants to make an exchange, please post your photo for consensus approval first.-Thanks-Pocketthis (talk) 18:09, 13 December 2014 (UTC)

• I really like that photo of the shooting stars below. I clicked on it, and it takes you off of Wikipedia to see it. If anyone knows the author personally, it would be great to have that uploaded to Wikipedia and displayed in our gallery. The photo clearly shows what appears to be two comets, and/or meteors and has a sunset to boot.-Pocketthis (talk) 18:52, 24 April 2015 (UTC)
  • Never mind, I found it, and will now post it.-Pocketthis (talk) 19:03, 24 April 2015 (UTC)

• I recently replaced the photo: Knysnasunset.jpg, that was only receiving Apox: 150 views per month in Commons, with the photo: Burning Yellow Sunset.jpg, that was receiving upwards of 270 views per month in Commons. Alvesgaspar has reversed me, and had some of his old friends come to his rescue by reversing me, as well as coming to my talk page and threatening me. I intend on holding strong here on solid ground. I made a logical edit that improves the boring red colors on the page, while proving its quality by posting the hits it gets in Commons. The average photo in commons gets around 20 hits a month. Both of the photos in question are far above average. The issue here is the fact that Alvesgaspar is positive that he owns this article. As anyone can read here on this talk page, the community consensus has spoken, and any reversal of my edit by Alvesgaspar or any of his long time friends, will be considered an "Edit War".→Pocketthis (talk) 18:38, 19 November 2014 (UTC) [copied from the section "Ownership issues" above]
• This kind of ad hominem attacks and accusations is improper of civilized editors and detrimental to the project. I respectfully suggest Pocketthis to withdraw those comments and apologize before the present issue is discussed. I also ask some uninvolved editor (an admin would be better) to roll back the article to before the picture replacement, that is, to 03:45 13 November. Alvesgaspar (talk) 20:28, 19 November 2014 (UTC)

• • I only stated facts. There is nothing to apologize for. If anyone should be apologizing, it should be you for the "hijacking" of this article for many years. The consensus of editors on this page has already spoken. We are relieving you of Command of this article. This article will be edited as any other article is edited, just like I edited it, and many others have attempted to until your reversals. If an Admin were to become involved, you would have to explain to him why you reversed my edit. NOT that it should be reverted to your version until settled. You will eventually end this conversation like you always do, claiming that "if we want to see Sunset photos.....that's what Commons is for". However, you are mistaken. Commons is the depository of uploaded photos where "we get the photos from to post in articles". The community has spoken here here already, and even though the outcome isn't what you'd like......it is what it is.→Pocketthis (talk) 20:59, 19 November 2014 (UTC)

• I wanted to add that I'm sorry that it had to get to this point. We have tried to reason with Alvesgaspar for at least as long as I've been an editor here, (Aug,2011), and for much longer than that when I would just visit this page as a reader. I try not to allow myself to think that it is ego driving Alvesgaspar, but rather a very technically educated photographer, whom has the idea that a technically perfect photo is more important than a sufficiently technical photo, even if the prior doesn't enhance the articles as well as the latter. He has been "deaf earing" the requests from other editors to put some variety on this page for so long, it has become increasingly easier for him to revert and ignore other editors every year. Sooner or later this day would eventually arrive. The day when an editor standing on firm ground tries to end the ownership of this article by Alvesgaspar. I waited for someone else to do it. Others have certainly tried right here on this page. I hope when the dust clears we can all learn to work together here, the way this place was designed to function. I harbor no ill feelings. I just want this page and the Sunrise page as well, to be edited fairly, correctly, and for the benefit of the readers, and not a photographer, science editor, or any other one individual.→ Pocketthis (talk) 21:26, 20 November 2014 (UTC)

As a photographer, I have been waiting almost a decade to see the sun setting in just the right atmosphere to allow itself to be crisp and photographed without any filter on my lens. It finally happened last night, June 06, 2015. I took over 50 shots as the sun sunk over the horizon. I then took a "midway" shot and made it the main photo of a collage of photos within the one frame showing the full cycle of the Sunset. I worked on it for many hours to get it to where I was satisfied. This will be a very educational photo, and I felt it belonged where I had my previous desert sunset shot. If anyone has a different opinion, or wants to argue my edit, please feel free to do it here. Thanks-Pocketthis (talk) 18:39, 7 June 2015 (UTC)

This bit from the intro seems to answer a question that hasn't been asked: "It takes over 8 minutes for the light from the Sun to reach the Earth. During that time, the Sun's position in the sky changes by approximately 2 degrees but this is due to Earth's rotation and surprisingly the delay in no way results in the Sun being below the horizon at sunset."

I can't imagine what this possibly contributes to the understanding of a sunset. Does the article on Sirius require a paragraph explaining why its motion across the sky isn't delayed by 8 years? I don't think so.

Furthermore, the Intro is supposed to summarize the main points of the article. This 8-minute thing is not such a point. Spiel496 (talk) 00:29, 5 February 2016 (UTC)

• If you read the edit summaries regarding that addition, you will discover that I personally commented that "I neither agree

nor disagree with the addition of this info, and that it was for the science editors to decide". My only concern was to correct the poor grammar that it arrived with. You are the science editor. That's that. Thanks for coming here first, but you didn't need to. I don't think anyone was crazy about that info being added, but since the facts appeared correct, it lasted until you reviewed it.-thanks- Pocketthis (talk) 00:51, 5 February 2016 (UTC)