1733: Solar Spectrum

Solar Spectrum

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Title text: I still don't understand why the Sun paid the extra money for Transitions lenses.

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Explanation

This is one of 63 incomplete explanations: This explanation does not meet our standards. The explanation itself goes all over the place, and table needs some serious work. Why does it keep saying "Agreement"? Who's agreeing? You can help by editing the explanation!

Spectral lines are a method of visualizing what types of light come from a light source. This is an example of the spectrum of the Sun. The various black lines represent chemical elements which are contained in the Sun, as, just like everything else, the Sun is made of elements. However, there are extra lines labeled "those giant sunglasses". The Sun does not actually have sunglasses, but there are often depictions of the Sun wearing sunglasses. These are not meant to be taken seriously.

The Sun's light blocked by sunglasses

The title text is a joke about the Transitions lenses you can get for eyeglasses. These are designed to turn black in the presence of ultraviolet light, and the Sun emits UV. This implies that not only does the Sun have vision problems, it bought Transitions glasses. This is extremely impractical, as in the very high UV radiation next to the Sun, the lenses would always be straight black, essentially canceling out any positive effect from the glasses.

The idea of a sun with sunglasses is a reference to pictures/clipart of the sun wearing sunglasses, often used to denote good weather. Randall has specifically used this picture in at least two what if? articles:

In Into the Sun it is seen in the fourth image. The title text of that image even references the fact that those sunglasses will block the light to Earth:

A partial solar eclipse is when the Earth moves across the part of the Sun blocked by its sunglasses.

This comic is a direct callback to this what if? article.

In Black Hole Moon it is in the first image, also including a banana as the mouth. Both the image and the title text of that image reference the fact that those sunglasses will block (eclipse) some of the light from Earth:

Doctors warn that even sunglasses that block UVB will only protect you from the part of the Sun covered by them.

There is another joke in drawing a Sun with sunglasses because sunglasses are meant to protect your eyes from the sun, so it is unclear what they would protect the Sun's eyes from (perhaps starlight?). Also, any glasses worn by the sun, would, in a sense, become 'sun glasses'.

Element	Wavelength (nm)	Comment
O	759.370	This line is outside the comic's range. So are the two unlabeled lines shown in the spectrum in the picture above around 720 and 730 nm. There are also even more oxygen lines further out in the infrared part of the spectrum not even included in the picture above.
Unlabeled	690	This is the fifth of the five xkcd sunglasses lines. This line is not labeled in the picture above. Wavelength estimated.
O	686.719	Agreement.
Unlabeled	577	This is the fourth of the five xkcd sunglasses lines. This line is not labeled in the picture above. Wavelength estimated.
Unlabeled	660	This line is not labeled, either in the comic or in the picture above. Wavelength estimated. It seems like this one was supposed to be one of the sunglasses lines, and then by mistake the arrow points to the line labeled C, below.
H	656.281	This is the third of the five xkcd sunglass lines. This is actually the Hα line belonging to the hydrogen Balmer series. Seems like a mistake, and more likely it was meant for the arrow to point to the unlabeled line mentioned above here.
Unlabeled	645	This is the second of the five xkcd sunglasses lines. This line is not labeled in the picture above. Wavelength estimated.
O	627.661	Agreement.
Na	589.592	Agreement. There is only one label in the comic (sodium) above these two close lines.
Na	588.995	Agreement. There is only one label in the comic (sodium) above these two close lines.
He	587.5618	This line is so close to the nearest sodium line that only one line is visible, so (both in the comic and in the picture above) only one is shown.
Unlabeled	577	This is the first of the five xkcd sunglasses lines. This line is not labeled in the picture above. Wavelength estimated.
Unlabeled	554	Agreement. This line is not labeled either in the comic or in the picture above. Wavelength estimated.
Unlabeled	549	Agreement. This line is not labeled either in the comic or in the picture above. Wavelength estimated.
Unlabeled	537	Agreement. This line is not labeled either in the comic or in the picture above. Wavelength estimated.
Fe	527.039	Agreement.
Mg	518.362	Agreement. See b below. There are only one label (magnesium) in the comic above these two close lines.
Mg	517.270	These two magnesium lines are so close that only one is visible in the spectrum, so only one is shown, both in the comic and in the picture above.
Fe	516.891	This iron line and the next magnesium line are so close that only one is visible in the spectrum, so only one is shown, both in the comic and in the picture above. There is only one label for both visible lines showing them to be magnesium, even though there are four lines (this one is iron).
Mg	516.733	Agreement. See b above. There are only one label (magnesium) in the comic above these two close lines.
Fe	495.761	Agreement.
H	486.134	Agreement with Hβ.
Unlabeled	476	Agreement. This line is also unlabeled in the table on Wikipedia. "h" is used between H and g below. The wavelength is estimated.
Fe	466.814	Agreement.
Fe	438.355	Agreement.
H	434.047	Agreement with Hγ.
Fe	430.790	Agreement.
Ca	430.774	Agreement.
H	410.175	Agreement with Hδ.
Ca	396.847	Agreement.
Ca	393.366	Agreement.
Unlabeled	389	This is the last line in the picture above. It is not included in the comic. There are even more lines outside the visible spectrum deeper into the ultraviolet which are not even shown in the picture above.

Transcript

[A chart shows the visible colored spectrum of the sun from deep violet to deep red. Along the spectrum are shown 28 black spectral lines of different thickness. Above the chart is a caption:]

The Sun's spectral lines

[Above the chart there are four and below the chart there are two labels, each label has one or more arrows pointing to different black lines. The two that has only one arrow points to two close lines marking them both. Only 22 lines are labeled like this, the other 6 are not labeled. The labels in reading order, with the number of arrows noted behind in square brackets:]

Calcium [3] Iron [5] Sodium [1] Oxygen [2]

Hydrogen [3] Magnesium [1] Those giant sunglasses [5]

Trivia

This comic's release day was postponed from the scheduled Wednesday release to a Thursday release because Randall noticed the extreme popularity of the previous comic on Monday: 1732: Earth Temperature Timeline. Randall even explained this in the header text; see this trivia item from the previous comic. Even though this comic was released on a Thursday, the scheduled Friday comic 1734: Reductionism was still released as planned. This was also the first time this occurred on xkcd - see this trivia section from the next comic, 1734: Reductionism.

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Discussion

Sun in sunglasses is also in whatif "Into the sun" and I'm 99% sure this is not the only xkcd appearance of that... --162.158.86.119 11:38, 15 September 2016 (UTC)

Why is Randall using JPEG for the second time in a row? Gosh, the comics look horrifying when zoomed in. 108.162.244.67 12:35, 15 September 2016 (UTC)

It looks like a .PNG to me, maybe the .jpg was temporary for an upload deadline? 108.162.241.127 12:54, 15 September 2016 (UTC)

The one on this page has always been a png file (see the first revision). This also means that whoever wrote the complaint must have had access to this same file, which has not been updated here since. Of course Randall may have had another version up first, but that seems highly unlikely... --Kynde (talk) 14:38, 15 September 2016 (UTC)

Are the spectral lines actually accurate apart from the sunglasses? Wouldn't surprise me to much... (Meh, https://en.wikipedia.org/wiki/Fraunhofer_lines, believably close). 141.101.105.10 12:51, 15 September 2016 (UTC)

Yes very accurate also the sunglasses lines are there in the real spectrum. --Kynde (talk) 11:43, 18 September 2016 (UTC)

I feel we need an explanation of the concept of spectral lines for those readers not familiar with absorption spectra 141.101.70.91 13:21, 15 September 2016 (UTC)

According to Wikipedia, absorption lines occur because solar radiation within the sun’s photosphere is absorbed at frequencies that match the energy difference between two quantum mechanical states of electrons bound to atoms or molecules. The absorption that occurs due to the transition between these two states is referred to as an absorption line and a spectrum is typically composed of many lines. These lines are dark because the light at those frequencies has been absorbed. In the case of an atom, absorption typically occurs when an electron is boosted from a less energetic inner orbital to a more energetic outer orbital in the process of absorbing a photon of light. Emission spectra are due to the opposite process.

Please consider the possibility that the title text mention of Transitions may hinge on the absorption process's quantum state transitions. Run, you clever boy (talk) 18:37, 17 September 2016 (UTC)

I think he's referring to the spectral lines of transition metals - not pictures of the sun wear glasses. The transition lenses reference is a play on words. 108.162.218.154 13:27, 15 September 2016 (UTC)

Can we figure out what sunglasses he is referring to by comparing the spectral absorption of different brands? 108.162.246.119 14:06, 15 September 2016 (UTC)

Any good links to "permanent" images of a sun with sunglasses? Guess there is none of Wikipedia? --Kynde (talk) 14:38, 15 September 2016 (UTC)

I agree this refers to "Transitions" light-reacting prescription sunglasses / regular reading glasses. However, Google won't give me a sun wearing sunglasses picture unless I type in "sun" and "sunglasses". Not for Transitions or Reactolite, not for weather forecasts, not for emojis. With eyes yes, big smile too, but not shades. I suppose because it actually is a stupid thing for the sun to have. Otherwise, nearest I get: http://www.essilor.com/en/BrandsAndProducts/Lenses/Photochromics/Pages/CrizalTransitions.aspx  :-) "30% faster" (than what? taking off the glasses?) Robert Carnegie [email protected] 141.101.98.90 15:11, 15 September 2016 (UTC)

See: http://imgur.com/a/35RDC 162.158.203.147 14:18, 15 September 2016 (UTC)

Is there a category for comics without characters? Are there enough comics to need a new category? GizmoDude (talk) 14:27, 15 September 2016 (UTC)

There are many many comics without characters, so it would be a huge job to make such a category and they do not necessarily have anything in common like two comics with Blondie for instance does. So I would say no. --Kynde (talk) 14:38, 15 September 2016 (UTC)

"Charts" looks right, seems implicitly to cover "infographics" (btw I agree with worrying about readers who don't know what spectral lines actually are although clearly everyone writing here does, or thinks so). Another possible edition for other cases is "Landscapes" but those in fact tend to have people in (or Mars rovers or such), also landscape in the sense of vista may be covered by "Large drawings" unless that specifically means "Image is larger than the pane on screen", since there also isn't a Scroll it" category. Alternatively... "Spectacles". Robert Carnegie [email protected] 141.101.98.90 15:23, 15 September 2016 (UTC)

Ya'll should keep in mind the large number of multivitamins that use rainbows as part of their branding and often some form of spectra/spectrum as part of the brand name. Here's a relevant image: http://centrum.com/sites/default/files/wheel_silver_adults_0.png 173.245.48.65 17:59, 15 September 2016 (UTC)

Except Centrum is the only brand I've seen that does that. 141.101.70.61 08:03, 16 September 2016 (UTC)

There's another image of a Sun with sunglasses (and a giant banana) at http://what-if.xkcd.com/129/ Jojonete (talk) 22:59, 15 September 2016 (UTC)

Great thanks adding this --Kynde (talk) 11:43, 18 September 2016 (UTC)

And perhaps we should acknowledge John Finnemore's terrific sketch about J M W Turner painting sunglasses on the sun (transcribed here: http://j-f-s-p.livejournal.com/5403.html). 141.101.70.49 (talk) 11:19, 16 September 2016 (UTC) (please sign your comments with ~~~~)

Given that all the lines for the sunglasses are in the red-orange spectrum I took it as a joke about glasses <a href=https://www.google.com/search?q=orange+wraparound&ie=utf-8&oe=utf-8#q=orange+wrap+around+glasses>similar to these.</a> Sorry I can't find the exact model I've seen in ads from the early 90s of wraparound over regular glasses that were orangish (old style Blue Blockers.) 108.162.216.128 14:22, 16 September 2016 (UTC)

The idea of the sun wearing transitions lenses became even more silly when I did a little research and found that the silver chloride that they often make transitions lenses with actually has a lower melting point (455°C) than glass itself typically has (1400°C to 1600°C.) I'm not sure that this has any relevance, but I was trying to find a plausible connection between the fabrication of transitions lenses as opposed to standard lenses and the use a sun (a sentient sun) might have for them. 173.245.50.83 15:37, 16 September 2016 (UTC) Sam

Hey, the example image of the sun's spectral lines in the description is just a tetch too big. I can't see it all at once, but if I set my zoom to 90%, I can see all of it just fine. I tried to resize it, but I'm not sure it worked. Feel free to revert it or fix it if you know how. NotLock (talk) 05:55, 18 September 2016 (UTC)

I have loaded a smaller version of the image from Wikipedia. Hope this workd, because with you edit the image did not show at all. --Kynde (talk) 11:43, 18 September 2016 (UTC)

Thanks! I think I tried to do a similar thing 6ish months ago, and it worked, but the image took time to render to a different size if I recall correctly (which I might not be doing at all). I googled "Wikipedia markup, and tried to follow the instructions there, but evidently it didn't work. Thanks for taking the time to fix this! -- NotLock (talk) 08:14, 19 September 2016 (UTC) (please sign your comments with ~~~~)

My impression, before reading the comments, was that "those giant sunglasses" referred to those giant novelty sunglasses that are usually used as a silly prop. 162.158.186.30 16:35, 15 October 2019 (UTC)

I'm going to get to work on this explanation. I am going to completely restart it, and people can build off my work if they want to. Majordesmosnerd (talk) 15:52, 5 October 2026 (UTC)

Should I remove the table? Majordesmosnerd (talk) 18:09, 5 October 2026 (UTC)

Depends on whether you can give sufficient information without it. You seem to think that you've got some good ideas for how to totally revamp it, so I was thinking that you would already have known what you'd do.

On the one hand, we can wait to see what you end up doing, perhaps finding it a better explanation. On the other hand, you know of course that someone might decide to revert it back to the current 'better' version. But we don't know really what'll happen until we see your version, of course. 92.23.3.72 21:36, 5 October 2026 (UTC)

Well, I also revamped it due to the reason why the explanation was incomplete. I think the table could be redone, but I'm not sure how. I think we should at least keep the nanometer values, I don't know how to estimate those, and the elements, but we don't need all that metadata. Majordesmosnerd (talk) 18:11, 6 October 2026 (UTC)

But, just so you know... If you're wanting to put in the {{Citation needed}} template then it's neater not to subst: it (if that's what you did). Similarly, the {{w}}-template is this site's highly prefered way of linking to a wikipedia article (see all the places it's currently used), rather than a [[]]-linke to wikipedia:<blah>. It's practically identical in the end, but is also more streamlined here in the source-editing process. 92.23.3.72 21:42, 5 October 2026 (UTC)

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I couldn't find the wikipedia link option in the visual editor. And honestly, who could I contact to request buttons for wikipedia links and citation needed insertion? Majordesmosnerd (talk) 23:55, 5 October 2026 (UTC)

Well, @FaviFake might be willing to do that.

Though, to be honest, buttons seem to be overkill for just typing a "{{" then "w", a pipe "|", and the text you copied from the desired Wikipedia page title (then optional second pipe/"|" and the different text you want the link to be) then a closing "}}" and you will have seen plenty of examples already in the page you were editing to clue you in. Considering how a button can't really do much except for giving you a {{w| <placeholder link> | <placeholder text> }} which you still need to paste/write things into, and possibly remove the "| <placeholder text> " bit if it's unnecessary. Perhaps add an "s" or an "'s" after the tag if you want it to be a plural or possessive, etc.

...but ignore all the finer points, for now. Whatever you did to get the [[wikipedia:<foo>|<bar>]], it's surely got to be easier to do {{w|<foo>|<bar>}} instead, right? 92.23.3.72 19:37, 6 October 2026 (UTC)

Huh, I don't know why the source did that. Again, I used the visual editor. Majordesmosnerd (talk) 14:14, 7 October 2026 (UTC)

Given that it looked like you'd "subst:"ed the Citation Needed tag, I'm wondering if you've somehow activated that effect globally. i.e. any time you use any {{template}} it'll convert it to the raw template-contents.

Just switched over to Visual editor for this edit, and back again, and I can't see any such setting. But maybe it's different for logged-in users, for some reason, or that they can hold persistent settings such as this in over in your master account-configuration page? 78.151.45.31 19:35, 7 October 2026 (UTC)

A few things:

@IP: Users are not using the {{w}} method because it's a pain in the ass to do on the Visual Editor. However, everything else is more intuitive, so it's a net good.

@IP: No, I don't think I can add a button to allow VE users to add {{w}}. I'm pretty sure I can't, but I haven't checked.

@Majordesmosnerd Even if we were able to add buttons, the last button I would add is a "citation needed" button. As the Editor FAQ § [Citation needed]: says: "This template should only be placed when there is a deeper sense of humor and should not be overused." It's internationally hard to insert because it should not be used often. 7 times out of ten, I have to remove them because they're not funny. Please read the EX:FAQ.

@IP It's not easier to do {{w|<foo>|<bar>}} instead, it's actually much harder on the VE. It's unfortunate, but it's an interesting problem. Why do we even use a template in the first place when we can just make a direct wikilink? I suspect the two methods of linking to Wikipedia will coexist in the future, depending on the editor used by the person who adds the link.

@IP, when Majordesmosnerd said "Huh, I don't know why the source did that.", they were referring to the Wikipedia link issue, not CN. See Special:Diff/419312.

@Both: I have no clue why the {{cn}} tag would subst itself, but I've never seen that happen before so hopefully it's just a fluke. It should be impossible to do that unintentionally on the VE. FaviFake (talk) 21:59, 7 October 2026 (UTC)

Ok, well, I don't use the WYSIWYG editor enough (i.e. at all, if I can help it) to know how difficult it has made very simple typing. And what's the point when the Source editor I'm using now, by way of the Reply link, has a WYSIWYG Preview below it? And even the 'regular old-school' editor can be Previewed, if necessary, to check one hasn't messed up a table. (Incidentally, I found the other day that you can't do Tables via the Reply method, given that it ruins the "start of line" requirements with the auto-:<indents>... Fun fact!) Meh, horses for courses.

When it turns out that apparently every wiki link they type went 'funny', I was using the fact that having first noticed the Citation Needed go funny (knowing that, in the past and before the Visual Editor was a thing, some people seemed to like to subst: some things for reasons apparently inherited from the practices on other wiki-projects, this looked like that at first), it appeared that there might have been a common factor running through the interface they used.

Anyway, I'm out of obvious ideas, beyond 'correcting' it when it's different. Except for "just don't bother with the Visual editor", though I suspect that's not exactly the most welcome of suggestions. However rewarding I think it is to be able to 'go raw'. Even if one won't do it all the time.

And, of course, the {{w}} doesn't just dumbly convert its parameters into [[]]-style wikipedia-linking, though the difference is subtle. 78.151.45.31 00:26, 8 October 2026 (UTC)

Not sure this is really the place for all this discussion - could we move it to one of the more general discussion pages - perhaps from the point I've indicated above? 86.22.132.121 08:54, 8 October 2026 (UTC)

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Why does the table keep saying "Agreement"? Majordesmosnerd (talk) 20:31, 16 October 2026 (UTC)

By the way, I don't really know what further I can do with the table. Majordesmosnerd (talk) 20:32, 16 October 2026 (UTC)
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