User talk:DVdm

— Welcome to my talk page — Please leave new comments at the bottom and sign them with tildes (~~~~) at the end. I'll respond here. If I have left a message on your talk page, please respond there. I'll try to keep an eye on it. If you think I forgot to check don't hesitate to remind me here. "They never be working' when they oughta should." "Watch out where the Huskies go, and don't you eat that yellow snow." "Remember there's a big difference between kneeling down and bending over." "Jazz is not dead, it just smells funny." "Everybody in this room is wearing a uniform, and don't kid yourself." vn-332This user talk page has been vandalized 332 times. — Canard du jour — As the light changed from red to greeen to yellow and back to red again, I sat there thinking about life. Was it nothing more than a bunch of honking and yelling? Sometimes it seemed that way. — Jack Handey This user has been on Wikipedia for 19 years, 6 months and 3 days. This user has earned the 100,000 Edits Award.

The Planets

Hi DVdm, I work for the publishing company that previously controlled the rights to this song. It is no longer copyright controlled in the U.S but may still be controlled in other countries with different copyright laws. Please reinstate my edit. 12.68.233.254 (talk) 20:50, 20 August 2018 (UTC)

Hi, the edit can be reinstated with a wp:reliable source. If you can provide such a source, I will reinstate it. Cheers - DVdm (talk) 06:25, 21 August 2018 (UTC)

MOS:LQ

I was surprised to see this, but even more surprised to see the rationale you quoted: "If the quotation is a single word or fragment, place the terminal punctuation outside. When quoting a full sentence, the end of which coincides with the end of the sentence containing it, place terminal punctuation inside..." The sentence fragment "never used LSD, never used cocaine, never used heroin or any of that other stuff" is not a "full sentence"—it couldn't stand alone—so the period cannot punctuate it. The period logically punctuates the enclosing sentence. Curly "JFC" Turkey 🍁 ¡gobble! 06:46, 6 September 2018 (UTC)

@Curly Turkey:, I agree that it is not a full sentence. It is of course the end of a full sentence, so I dragged it into the other part of the grey zone . Thanks for your message here—I was about to write this on your talk page. Cheers! - DVdm (talk) 06:54, 6 September 2018 (UTC)

About my writing of the Ignorre prize

Hello DVdm, Thank you very much for writing the talk to me I’m writing this talk because I’d like you to understand what I want to do. I wanted to be able to go to items quickly without pushing each content. On the Wikipedia Ignor Prize page in Japanese there is the same thing as I did. I thought that this sentence can be used more conveniently by users. Since it may not be transmitted unless it is in Japanese, I write it in Japanese below I am sorry for my selfish writing.

(Japanese) 初めてお目にかかりますDVmd様。私は『舌先現象になります』と申します。お忙しいなか私にtalkをお書きになさり誠に有難うございます。私がDVmd様にtalkを致す理由は自分の考えを御理解していただきたかった次第であります。私が執筆はコンテンツを毎度押さなくとも直ちにその年の項目にいくことが出来るようにしたかったのです。日本語版ウイキペディアでは私が英語版でした執筆行為と類似しております。私はこの方が利用者にとってより良く利用できると思っておりました。 不甲斐ない英語で申し訳ありません

Regards, 舌先現象になります 舌先現象になります (talk) 14:35, 15 September 2018 (UTC)

@舌先現象になります: hi, just so you know, we do not add such tables of content on the English Wikipedia. Cheers. - DVdm (talk) 14:50, 15 September 2018 (UTC)

NPR Newsletter No.13 18 September 2018

Hello DVdm, thank you for your work reviewing New Pages!

The New Page Feed currently has 2700 unreviewed articles, up from just 500 at the start of July. For a while we were falling behind by an average of about 40 articles per day, but we have stabilised more recently. Please review some articles from the back of the queue if you can (Sort by: 'Oldest' at Special:NewPagesFeed), as we are very close to having articles older than one month.

Project news

• The New Page Feed now has a new "Articles for Creation" option which will show drafts instead of articles in the feed, this shouldn't impact NPP activities and is part of the WMF's AfC Improvement Project.

As part of this project, the feed will have some larger updates to functionality next month. Specifically, ORES predictions will be built in, which will automatically flag articles for potential issues such as vandalism or spam. Copyright violation detection will also be added to the new page feed. See the projects's talk page for more info.

• There are a number of coordination tasks for New Page Patrol that could use some help from experienced reviewers. See Wikipedia:New pages patrol/Coordination#Coordinator tasks for more info to see if you can help out.

Other

• A new summary page of reliable sources has been created; Wikipedia:Identifying reliable sources/Perennial sources, which summarizes existing RfCs or RSN discussions about regularly used sources.

Moving to Draft and Page Mover

• Some unsuitable new articles can be best reviewed by moving them to the draft space, but reviewers need to do this carefully and sparingly. It is most useful for topics that look like they might have promise, but where the article as written would be unlikely to survive AfD. If the article can be easily fixed, or if the only issue is a lack of sourcing that is easily accessible, tagging or adding sources yourself is preferable. If sources do not appear to be available and the topic does not appear to be notable, tagging for deletion is preferable (PROD/AfD/CSD as appropriate). See additional guidance at WP:DRAFTIFY.
• If the user moves the draft back to mainspace, or recreates it in mainspace, please do not re-draftify the article (although swapping it to maintain the page history may be advisable in the case of copy-paste moves). AfC is optional except for editors with a clear conflict of interest.
• Articles that have been created in contravention of our paid-editing-requirements or written from a blatant NPOV perspective, or by authors with a clear COI might also be draftified at discretion.
• The best tool for draftification is User:Evad37/MoveToDraft.js^(info). Kindly adapt the text in the dialogue-pop-up as necessary (the default can also be changed like this). Note that if you do not have the Page Mover userright, the redirect from main will be automatically tagged as CSD R2, but in some cases it might be better to make this a redirect to a different page instead.
• The Page Mover userright can be useful for New Page Reviewers; occasionally page swapping is needed during NPR activities, and it helps avoid excessive R2 nominations which must be processed by admins. Note that the Page Mover userright has higher requirements than the NPR userright, and is generally given to users active at Requested Moves. Only reviewers who are very experienced and are also very active reviewers are likely to be granted it solely for NPP activities.

List of other useful scripts for New Page Reviewing

Twinkle provides a lot of the same functionality as the page curation tools, and some reviewers prefer to use the Twinkle tools for some/all tasks. It can be activated simply in the gadgets section of 'preferences'. There are also a lot of options available at the Twinkle preferences panel after you install the gadget. In terms of other gadgets for NPR, HotCat is worth turning on. It allows you to easily add, remove, and change categories on a page, with name suggestions. MoreMenu also adds a bunch of very useful links for diagnosing and fixing page issues. User:Equazcion/ScriptInstaller.js(info): Installing scripts doesn't have to be complicated. Go to your common.js and copy importScript( 'User:Equazcion/ScriptInstaller.js' ); into an empty line, now you can install all other scripts with the click of a button from the script page! (Note you need to be at the ".js" page for the script for the install button to appear, not the information page) User:TheJosh/Scripts/NewPagePatrol.js(info): Creates a scrolling new pages list at the left side of the page. You can change the number of pages shown by adding the following to the next line on your common.js page (immediately after the line importing this script): npp_num_pages=20; (Recommended 20, but you can use any number from 1 to 50). User:Primefac/revdel.js(info): Is requesting revdel complicated and time consuming? This script helps simplify the process. Just have the Copyvio source URL and go to the history page and collect your diff IDs and you can drop them into the script Popups and it will create a revdel request for you. User:Lourdes/PageCuration.js(info): Creates a "Page Curation" link to Special:NewPagesFeed up near your sandbox link. User:Writ Keeper/Scripts/deletionFinder.js: Creates links next to the title of each page which show up if it has been previously deleted or nominated for deletion. User:Evad37/rater.js(info): A fantastic tool for adding WikiProject templates to article talk pages. If you add: rater_autostartNamespaces = 0; to the next line on your common.js, the prompt will pop up automatically if a page has no Wikiproject templates on the talk page (note: this can be a bit annoying if you review redirects or dab pages commonly).

Go here to remove your name if you wish to opt-out of future mailings. MediaWiki message delivery (talk) 23:11, 17 September 2018 (UTC)

Hope

Thank you for your comment, and I hope you will not block me.Aetzbarr (talk) 09:09, 22 September 2018 (UTC)

Please put new talk page messages at the bottom of talk pages — See Help:Using talk pages. Thanks.

@Aetzbarr: I can only report you at, for instance, wp:AIV. Then an administrator will take care of the blocking. Good luck. - DVdm (talk) 09:46, 22 September 2018 (UTC)

Sorry I am still here !

I feel more and more like an old (82) actor replaying endlessly the same final scene ! But when I detect an scientific anomaly I feel morally obliged to undertake an action.

So I returned to your refutation of Dingle. Dingle’s argument was obviously false. But not for the reason you exhibited ! You committed the same error !

You and Dingle mistook the rate of the clock with the measured time itself. I May 2017 I should have noticed that your false calculation induced you to write:

(3) rate A / rate B = 1/a  ?

(4) rate B / rate A = 1/a  ?

If that were true , that means that the rate of each clock would depend of it’s usage !

In “reductio ad absurdum “ that is an indirect demonstration of :

              rate A = rate B

« Il ne saurait pas en être autrement « 

Don’t mention the rates and your refutation will be valid !

Cordialement Chessfan (talk) 09:12, 26 September 2018 (UTC)

Have another very careful look... until you get it... . Cheers and happy lichessing! - DVdm (talk) 09:26, 26 September 2018 (UTC)

I got it ! Our dialogue would be easier if you added geometric algebra to your mathematical skills. You will find me easily if you look in French internet “algèbre géométrique « ... 🤫 Cheers — Preceding unsigned comment added by Chessfan (talk • contribs) 16:27, 28 September 2018 (UTC)

Subjective editing

Yes, please excuse me for "hot comments". Please note, that I believe, that editor Prokaryotic Caspase Homolog (talk) conducts subjective editing, which is not in accordance with WP:NPOW and is not solidly backed by reputable sources. I believe that you are not the supreme power here, so, could you please to let me know, how to bring this issue to the discussion? Can I appeal to a higher authority to resolve the issue? Best personal regards,Albert Gartinger (talk) 19:09, 30 September 2018 (UTC)

@Albert Gartinger: you should immediately stop making threats like "That's that. I will turn the whole article into a piece of smelly shit" and "I will ask my secretary to prepare a list of target audience. I will send thousand, or tens of thousands of emails. I have enough time". Next time I will report you at wp:ANI, and you can be 100% sure that you will get blocked. Believe me, you are one inch away from that.

Note that I don't think that you will get your way, as I agree with user Prokaryotic Caspase Homolog (talk · contribs) on the dispute. His version is directly backed by a good source. Your version is wp:synthesis of sources, and therefore amounts to wp:original research, which is forbidden in Wikipedia. - DVdm (talk) 19:27, 30 September 2018 (UTC)

If you have a content dispute that is not going to be resolved on the article talk page (or on user talk pages), you can find out what to do by reading the policy article wp:Dispute resolution. You'll see what to do there. Again, I'm pessimistic about your chances of success. - DVdm (talk) 19:27, 30 September 2018 (UTC)

Dear Sir! Thank you very much for your answer. Please note, that my analysis is solidly and directly backed by the celebrated paper of Albert Einstein "ON THE ELECTRODYNAMICS OF MOVING BODIES", $7, Theory of Doppler's principle and of aberration. Please note that Mr. Einstein gives Doppler shift formula for moving observer. However, the editor Prokaryotic Caspase Homolog (talk · contribs) (who confessed himself, that Einstein is the "primary source"), relies on a little-known source. Please note, that my attempts to explain to the editor Prokaryotic Caspase Homolog (talk · contribs), that the observer on the diagram must (or at least can) be moving, were met by fierce opposition, that contradicts to the mentioned above paper of A. Einstein, who clearly says, that the observer is moving. This editor Prokaryotic Caspase Homolog (talk · contribs) willfully draws only moving sources. Apparently he is an ardent supporter of some physical theory, which assumes that there is only absolute motion of sources, but not observers. Dear Sir! Could you please to note, that such a theory is hardly backed by any reputable sources and sounds very quirky and unusual. I don't believe, that such a worthy and educated person like you, must cover violations of Wikipedia policies. Kind regards, Albert Gartinger (talk) 19:51, 30 September 2018 (UTC)

Please also note, that mentioned above Doppler shift formula in the paper of A. Einstein clearly indicates, that since the observer moves, observer's clock dilates (time dilation is assigned to moving observer, so according to Mr. Einstein, source's clock (which is at rest) ticks faster (square root is in denominator). That clearly contradicts to the very quirky claims in the chapter Mutual Time dilation of the article Spacetime. I suppose, that this way the editor Prokaryotic Caspase Homolog (talk · contribs) knowingly and willingly wishes to lead readers astray in order to promote his original research, the theory of moving sources! Sincerely yours, Albert Gartinger (talk) 20:10, 30 September 2018 (UTC)

Please indent your talk page messages as outlined in wp:THREAD and wp:INDENT — See Help:Using talk pages. Thanks.

For now, I am not going into the technicalities on this. I'll take the sideline.

In addition to the policies to which I pointed in my previous message, do note that "primary sources" have a special meaning in Wikipedia. This was explained by PCH in this message. To save time, perhaps he should have pointed you to the relevant policy article. You find it here: wp:Primary sources. It is a section in the policy article wp:No original research to which I pointed above. Please read carefully, for if/when you go for extended dispute resolution, you will need to understand what is said there. - DVdm (talk) 20:27, 30 September 2018 (UTC)

I would like to involve some more Wikipedia editors to this discussion, because now there are only two participants I - and Prokaryotic Caspase Homolog (talk), each of us has his own reliable sources and interpretations of these sources. Is it allowed to post on other Wikipedia editor's talk pages invitation to participate in the discussion? Is other editor's talk page is a place to discuss the matter without formal rules, that apply to article's talk page? Thank you very much for your kind advice Albert Gartinger (talk) 19:44, 4 October 2018 (UTC)

See wp:Dispute resolution and wp:Dispute_resolution_requests. Your best best probably is one of the wp:Dispute_resolution_requests/Noticeboards, or wp:Requests_for_comment. - DVdm (talk) 20:59, 4 October 2018 (UTC)

Dear DVdm (talk), I think that would be a bit premature rashly start initiating disputes, we are still in talks with Prokaryotic Caspase Homolog (talk on his talk page. We have enough time. However, I have noted, that there are WikiProjects groups. Do you think it is appropriate to seek some advice there (which group? WikiProject Physics in regard of this diagram, particularly drawing moving observer in case a. I would like to clarify the situation whether it is convinient to draw moving observers on diagram. Thank you very much for your kind support and understanding Albert Gartinger (talk) 11:47, 5 October 2018 (UTC)

Yes, Wikipedia talk:WikiProject Physics is the place to go. Open a little section and ask for advice and input about what's going at Talk:Spacetime. That should have the same effect as a formal WP:RFC. - DVdm (talk) 12:50, 5 October 2018 (UTC)

Boldface in Lead

Please refer to WP:BOLDAVOID before reverting my edits. It states two things of note to us: the lead sentence shouldn’t be made unnatural by the bold and links shouldn’t be put in bold. IWI (chat) 10:27, 8 October 2018 (UTC)

@ImprovedWikiImprovment: please have a look at wp:Edit warring and wp:BRD. You made some bold edits ^{(pun intended)} and I reverted them. Now you should discuss, and then perhaps we could undo the reverts. Don't just undo and then try to discuss.

There are perhaps thousands of list articles that open with "The following is a list of ...." Are you going to subject them all to your treatment? - DVdm (talk) 11:42, 8 October 2018 (UTC)

The main issue was links in boldface, which is never allowed. IWI (chat) 12:20, 8 October 2018 (UTC)

Also keep in mind that the BRD is optional; when there is a guideline blatantly backing up my edit, we don’t need to discuss. IWI (chat) 12:37, 8 October 2018 (UTC)

Just be careful . - DVdm (talk) 13:14, 8 October 2018 (UTC)

leonardo lopez lujan

Thank you for your advice about my edit to this page. I have referenced it as you requested and restored my original edit. 205.239.98.30 (talk) 14:07, 17 October 2018 (UTC)

Ok. - DVdm (talk) 14:33, 17 October 2018 (UTC)

leonardo lopez lujan

Thank you for your advice about my edit to this page. I have referenced it as you requested and restored my original edit. 207.37.196.254 (talk) 14:18, 17 October 2018 (UTC)

And OK too. - DVdm (talk) 14:34, 17 October 2018 (UTC)

NPR Newsletter No.14 21 October 2018

Chart of the New Pages Patrol backlog for the past 6 months.

Hello DVdm, thank you for your work reviewing New Pages!

Backlog

As of 21 October 2018, there are 3650 unreviewed articles and the backlog now stretches back 51 days.

Community Wishlist Proposal

• There is currently an ongoing discussion regarding the drafting of a Community Wishlist Proposal for the purpose of requesting bug fixes and missing/useful features to be added to the New Page Feed and Curation Toolbar.
• Please join the conversation as we only have until 29 October to draft this proposal!

Project updates

• ORES predictions are now built-in to the feed. These automatically predict the class of an article as well as whether it may be spam, vandalism, or an attack page, and can be filtered by these criteria now allowing reviewers to better target articles that they prefer to review.
• There are now tools being tested to automatically detect copyright violations in the feed. This detector may not be accurate all the time, though, so it shouldn't be relied on 100% and will only start working on new revisions to pages, not older pages in the backlog.

New scripts

• User:Enterprisey/cv-revdel.js^(info) — A new script created for quickly placing {{copyvio-revdel}} on a page.

Go here to remove your name if you wish to opt-out of future mailings. — Insertcleverphrasehere ^{(or here)} 20:49, 21 October 2018 (UTC)

Thermal conductivity

Hi, the article on Thermal conductivity says that the phase velocity of longitudinal waves is much greater than for transverse waves, such that their group speed is also larger. I thought that must be a typo, as the phase velocity doesn't determine the group speed in general. Thinking about it, I guess since both dispersions are gapless and heat is carried mostly by long wavelength phonons, this is true, but perhaps still not obvious. Apologies for the stray incorrect "correction" :) 130.183.93.92 (talk) 09:55, 23 October 2018 (UTC)

(Moved to bottom per wp:TPG)

That's why Wikipedia demands sources . Cheers - DVdm (talk) 10:09, 23 October 2018 (UTC)

Not happy with Special relativity article

I'm seriously thinking of downgrading Special relativity from B-class to C-class. I just finished giving it a thorough reading, and it strikes me as a junk pile of separate essays with no clear focus and which are not ordered in any rational fashion. A certain amount smells like original research. Not necessarily wrong, but either unsourced or idiosyncratically sourced. (Really now, a reference to the entire book The Road to Reality without a page number just does not qualify as a legitimate source. Likewise, a reference without page numbers to an old Dover reprint with a dated approach to the subject is just a pretend reference.)

Problem is, if I downgrade the article, I'd feel obligated to rewrite the article. Unlike Relativistic Doppler effect, which took only 10 days to get into a basically decent shape (although I keep finding small things that need tweaking), Special relativity would be a several months-long project, and I'm just not up to it.

Thoughts? Prokaryotic Caspase Homolog (talk) 09:21, 25 October 2018 (UTC)

I haven't read the entire article, so I can't assess its condition. Its one of many articles that I guard against vandalism/mistakes/nonsense, and to which I only made small sourced contributions. Perhaps it's best to clean it from the obvious junk, as opposed to rewriting. The latter might (re-)open a can of worms . - DVdm (talk) 10:09, 25 October 2018 (UTC)

I've limited myself so far to rearranging the article to push the unsourced (and requiring junior-senior level math skills) sections to the end, adding transitional phrases, and fixing undecipherable figures. I am now expanding a few sections. I am still unhappy with the article, having discovered that the approach of the earliest authors was to derive everything from the single postulate of universal Lorentz covariance. To me, this means that from a usefulness to primary audience standpoint (which I generally assume to be high school to lower division college students), it will never achieve B-class status. Prokaryotic Caspase Homolog (talk) 12:25, 4 November 2018 (UTC)

No problem. To me, it looks fine. - DVdm (talk) 12:43, 4 November 2018 (UTC)

Galileo

Hi @DVdm:. The lead sentence of Galileo is currently/recently under discussion on talk:Galileo. Please join in on the discussion. Best, James343e (talk) 18:37, 23 October 2018 (UTC)

Yep, see [1]. Cheers. - DVdm (talk) 17:25, 26 October 2018 (UTC)

Lorentz Transform

Hi, I recently made an edit to the Lorentz transform page. I'm not sure what you expected me to provide a source for, because my change was pretty much just some algebra to make things clearer. I was going back to change the plus signs back to minus signs when I saw that you reverted the whole thing, because the plus sign is for when you're moving the future world line to the positive direction, which is just a sign convention that is used only in some contexts, and so it wasn't appropriate. The rest is just algebra to make everything clearer, and it's directly related to: https://en.wikipedia.org/wiki/Four-vector#Pure_boosts_in_an_arbitrary_direction. When you draw a Minkowski diagram, you have an x and a ct axis, and the reason is so that the eigenvectors (which are the light-like vectors) are (1,1) and (1,-1), in other words, the line of light like event separations is at a 45 degree angle. For this reason (and so that the components have the same units), four vectors are typically written as (ct, x, y, z) for position, (E/c, p_x, p_y, p_z) or (E, cp_x, cp_y, cp_z) for four momentum, or A = (phi/c, a_x, a_y, a_z) for the electromagnetic four potential and so on, which are discussed to some extent on https://en.wikipedia.org/wiki/Four-vector. A source that supports what I'm saying is: http://web.hep.uiuc.edu/home/serrede/P436/Lecture_Notes/P436_Lect_16.pdf

I am a physics doctoral student, and so I don't remember all of the places I saw this clearer way to write it, but what I do know is that the first time I learned special relativity, the professor used the notation that is currently on the Lorentz transformation page, and people constantly made mistakes with it or couldn't keep the two straight etc, whereas writing it the way I did makes it very easy to remember, and it matches https://en.wikipedia.org/wiki/Four-vector#Pure_boosts_in_an_arbitrary_direction except there sinh and cosh are used, and explaining how to get to that is something I could do. My aim with making this edit was to save many students the trouble that I had and that I have seen many fellow students have, and now that I am TAing, my students are having this same very difficulty. For the nice way, you only need to remember a very simple matrix, ${\begin{pmatrix}ct'\\x'\end{pmatrix}}=\gamma {\begin{pmatrix}1&-\beta \\-\beta &1\end{pmatrix}}{\begin{pmatrix}ct\\x\end{pmatrix}}$

Obviously, most people won't actually know about matrices, so that's why I didn't write it like this, but the point is how simple and symmetric it is. Given this, is my edit not sensible? Mr. HelloBye (talk) 03:35, 4 November 2018 (UTC)

Lecture notes tend to have only a transient duration on the web, so if you intend to use the P436 lecture notes as a source, be sure to use an archived link to the pdf (Internet Archive or Webcite) in addition to the current link. Be sure that you proof your changes in your sandbox before publishing them in main space! A favorite trick of vandals nowadays is to open a user name for vandalism purposes, and to make subtle changes that will not get detected by a bot and may sneak by a human monitor. All of us who regularly patrol for vandalism tend to be very suspicious of sign errors! Prokaryotic Caspase Homolog (talk) 04:47, 4 November 2018 (UTC)

Hi Mr. HelloBye (talk · contribs), I know the form that you proposed, but the current form of the transformation seems more common. If we want Wikipedia to say that another form is the simplest, then we preferably need a relevant, established book source—as opposed to some lecture notes by some lecturer—that indeed says that is the simplest form. Of course, we also should make sure that we have the signs correct. The Wikipedia way is wp:reliable sources and wp:secondary sources. Cheers - DVdm (talk) 08:59, 4 November 2018 (UTC)

I will look further for a book with this convention, but I honestly imagined that it is readily apparent/self evident that this way is the simpler way to write it. As for the sandbox, I'm fairly new to editing for wikipedia, so I don't know what that is. Obviously, my intent is to help newbies here. There's enough weird things about special relativity, and writing the equation in a relatively obtuse way only serves to exacerbate this. The reason for the negative sign is that that's when you are changing to the frame that is moving in the positive direction, and as I said, when I realized that was what was indeed originally intended, I went to change the sign back to negative. Can you at least see anything wrong with adding the expression that I propose like "with some algebra, it can be rewritten this way"? I don't need to make the claim that this way is most simple. Really, I just think it would help relativity newbies to see this way of writing it as well. Part of the issue with a book source in this situation is that there are traditions in any subject being taught (this is one of them), and so most authors just follow the group with something like this. I'm sure there's a book somewhere with this way of writing it, but I am not sure how I would find it and for what? With some simple algebra is a perfectly reasonable thing for an author to say, and I was able to find in a couple minutes two examples of wikipedia articles using it: https://en.wikipedia.org/wiki/Angle_of_view#Macro_photography and https://en.wikipedia.org/wiki/Triangular_number#Other_properties