User talk:DVdm/Archive 2020

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Re-applied correction

I noticed that you reverted a single-letter formatting correction I made to the article on W and Z bosons, and no, I wasn't experimenting with edits. Because some other changes had happened in the meantime, I just re-applied the change: The symbols for the W bosons immediately preceding the naked-Z in the 2nd sentence have superscripts, and the Z⁰ following has a superscript-zero, so it seems to me that in the line that states "this is the symbol for the Z-boson, the (admittedly redundant) superscript should be on that letter 'Z' as well. Since it's an encyclopedia article for the not-yet facile, and the introduction of the representative symbols, it ought to be consistent; Consistency is the hob-goblin of small minds, so here I am.

And a happy Christmas still (we've got until 12th-night, the 6th!), and happy new year.

71.94.235.196 (talk) 23:02, 2 January 2020 (UTC)

Oops yes, my mistake. Apologies and best wishes! - DVdm (talk) 23:17, 2 January 2020 (UTC)

the next time...

... you inappropriately use a rollback bot to remove VERIFIED, SOURCED MATERIAL under some misunderstanding of BLP, I won't warn you - I will go directly to ANI and ask for a perma-block. I'm restoring the prison sentence of Napoleon Murphy Brock to his bio - and that TP - now. 50.111.62.84 (talk) 04:29, 6 January 2020 (UTC)

@50.111.62.84: some material that is verified and sourced can still be inappropriate in a wp:BLP, as was explained earlier at User talk:213.149.61.113 and recently here. By the way, the material was revdelled by the wp:oversight team. - DVdm (talk) 07:33, 7 January 2020 (UTC)

Garden Gnome

Huh? A friendly talk page gnome showed up in your garden with a puff of smoke! Wonder why it's here, you didn't see anything else happen lately... --moonythedwarf (Braden N.) 15:25, 30 January 2020 (UTC)

@Moonythedwarf: thx - DVdm (talk) 15:31, 30 January 2020 (UTC)

New Page Reviewer newsletter February 2020

Hello DVdm,

Source Guide Discussion

The first NPP source guide discussion is now underway. It covers a wide range of sources in Ghana with the goal of providing more guidance to reviewers about sources they might see when reviewing pages. Hopefully, new page reviewers will join others interested in reliable sources and those with expertise in these sources to make the discussion a success.

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16:08, 13 February 2020 (UTC)

Pseudoscience

Hi.

What is the issue of adding "mainstream" in front of "scientific method"? Several of the disciplines that are claimed to be pseudoscience argue that scientific method, in its mainstream form, has its flaws, and that there is no such thing as "a" scientific method. They would therefore claim that their science fulfills the criteria of scientific method, but many would concede that it doesn't fulfill the criteria of ordinary or mainstream scientific method. See for instance the Stanford Encyclopedia of Philosophy, that talks about the "legend of a single, universal scientific method". For this reason, it would in my opinion add clarity to add "mainstream" in front of "scientific method". — Preceding unsigned comment added by 129.240.213.52 (talk) 16:55, 3 March 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

If a source uses the term "scientific method", then Wikipedia mentions "scientific method". Adding something to it is wp:original research, specially in an article with a subject that is related to the very term. - DVdm (talk) 17:00, 3 March 2020 (UTC)

Taylor series

My edit about Taylor series was reverted due to being a "test edit" even though it was not a test. I simply corrected the see also link.

96.78.246.25 (talk) 15:52, 10 March 2020 (UTC)

Ok. - DVdm (talk) 16:21, 10 March 2020 (UTC)

Acceleration rank 2 per Einstein's General Relativity

On the Acceleration talk page, I did as the admins asked and cited references proving that the acceleration tensor is rank 2. It was removed (presumably due to my warnings about the user hijacking the nym RealOldOne2)... I've re-entered the data, with an additional published cite EXPLICITLY stating that the acceleration tensor is rank 2 (the second derivative of the metric, the first derivative of the Christoffel symbol... otherwise known as the Einstein tensor). 71.135.43.236 (talk) 03:27, 25 March 2020 (UTC)

See [1] and [2]. - DVdm (talk) 07:57, 25 March 2020 (UTC)

WTF is "disruptive" about PROVIDING THE PUBLISHED SOURCES THE ADMIN ASKED FOR? That you guys cannot understand the mathematics is quite apparent, which is why you keep claiming that "the text doesn't state that acceleration is a rank 2 tensor"... if the right-hand side of the equation (proportional to the energy-momentum tensor) is a rank 2 tensor, the left-hand side of the equation (acceleration due to gravity) is a rank 2 tensor.

I've got more published sources, if you need them... ALL of them stating that the acceleration tensor is rank 2 in 4-D Minkowskian or Lorentzian space. Your claim that acceleration is rank 1 is for 3-D space, but 3-D space is an approximation of 4-D space, for a localized problem, used only to simplify the equations... aren't we supposed to be representing the physical quantities as they are in the real world? Or are we representing them as simplifications and approximations? 71.135.43.236 (talk) 08:40, 25 March 2020 (UTC)

On Frank Zappa's Grand Wazoo

i dont think i'd have to add a source, it's literally just his 8th studio album with the MOI and the MOI's 10 overall — Preceding unsigned comment added by 72.82.29.148 (talk) 20:17, 27 March 2020 (UTC)

See The Grand Wazoo on the official Frank Zappa biography, which says that TGW is "Official Release #16". Note that whether a Zappa album is a studio album or a live album is very problematic, if not impossible. Cheers. - DVdm (talk) 20:25, 27 March 2020 (UTC)re

Centripetal Force page

You said: " 09:07, 3 August 2018‎ DVdm talk contribs‎ 50,913 bytes -210‎  Bwas better before. No need for math tags for inline math undothank". What does "bwas" mean? Also, why do you hold this view? Look at this: are the highlighted symbols the same? I dunno. They look *very* different!

This, on the other hand, is much more readable and looks *identical*.

So, why'd you undo my edit? ERCaGuy (talk) 23:04, 5 April 2020 (UTC)

No, they don't look the same, but using inline math with italicized characters is common practice (see a.o. MOS:FORMULAE), and other editors seem to agree. You are welcome to go to the article talk page and start a discussion about it.

"Bwas" is the past tense of the verb "to bwe" . I already put that straight in the summary of my next edit ([3]), five minutes later. - DVdm (talk) 06:57, 6 April 2020 (UTC)

A barnstar for you!

	The Original Barnstar
	hello, i see u sent me a message becasue i removed an unnecessary extra detail from the "cacık" page because it was way confusing and it was ridicilous harming the content. Btw, i am new to this stuff so Ii appreciate for ur help if u let it stay like that the knowledge for that wont be confusing and much more plainwithout harming the topic. Tx Samilc87 (talk) 09:34, 7 April 2020 (UTC)

Huh?

I don't see how what you messaged me relates to what I posted. I strongly suspect you didn't read my comment at all. — Preceding unsigned comment added by 2A02:A457:9497:1:F938:499E:52BC:CB4C (talk) 12:01, 25 April 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

Oops, sorry, my mistake. I restored the comment and replied ([4]). - DVdm (talk) 12:37, 25 April 2020 (UTC)

Gamma function Page

I have added some notes for editors on the "Gamma function" talk page how to improve the main page. The notes were added such that editors get a better understanding which concepts are relevant and why those concepts should be highlighted (e.g. because material on other pages uses those concepts, like the calculation of the Gaussian integral). Also, I added a note in order to avoid a common pitfall when writing certain formulas (Gamma(1/n) vs PI(1/n)). Unfortunately, the notes were deleted by Sapphorain. But the notes would be relevant for any editor who wants to improve the main page.

Just out of curiosity: do the editors of mathematical pages have a sufficient mathematical background? Do they have some formal training or experience in giving/preparing lectures? Or how to write educational content? — Preceding unsigned comment added by Leo.Mathematics (talk • contribs) 17:54, 25 April 2020 (UTC)

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Wikipedia content needs to be reliably sourced, and editors' backgrounds are of no importance whatsoever in Wikepedia. See, for instance, the essays wp:There is no credential policy, wp:Ignore all credentials, wp:Credentials are irrelevant. - DVdm (talk) 18:07, 25 April 2020 (UTC)

Jean-Pierre Vigier

Hello. You undid a reference edit I made to the page recently. The URL provided is a larger archive in which the journal volume cited is contained. Shall I redo the citation to the printed volume, but with a pointer to the URL for the archive in which it is contained? Or simply omit any link to the online archive? Thank you. Mischievousgnome (talk) 15:48, 28 April 2020 (UTC)

Hi Mischievousgnome, if indeed there somewhere exists an explicit list of "Papers in Honour of Jean-Pierre Vigier on the Occasion of his Seventieth Birthday", then that list could be mentioned (as a wp:primary source) in the article. O.t.o.h. if that list only exists when compiled from a lager list, as you did there, then, per wp:SYNT and wp:OR, it would be inappropriate. So I don't think there's anything to link or even mention about such papers, and/or the reason why they were produced. - DVdm (talk) 16:03, 28 April 2020 (UTC)

Thank you for your response. The special double issue of the journal (ISSN 0843-6061) was produced on paper before there was a website, so the physical issue exists and can be referenced. The online archive was created to afford access to all issues of the journal at a single source. In that archive the conference proceedings are identified as belonging to the double issue (Nrs. 9-10, Winter-Spring 1991 and named "Festschrift Vigier - Papers in honour of...") in the journal archive. Hence the referenced issue exists within the journal archive and the individual contributions to the issue are accessible in that archive.Mischievousgnome (talk) 16:46, 28 April 2020 (UTC)

i did not like what you did

	i did not like what you did
	I just added some more text for others! K.S.Harshada (talk) 07:39, 5 May 2020 (UTC)

@K.S.Harshada: I understand, but do see our policy about wp:reliable sources. - DVdm (talk) 07:42, 5 May 2020 (UTC)

A barnstar for you!

	The Original Barnstar
	ok,done K.S.Harshada (talk) 07:44, 5 May 2020 (UTC)

Multiple time dimensions

Hi, could you tell me how correcting the italics was wrong? $\color {blue}\chi$_chi (talk) 12:31, 7 May 2020 (UTC)

Hi Χ, with this edit you just had replaced E with E', so I wrongly corrected it with this. My mistake. I should have done this. Thanks for having noticed! - DVdm (talk) 12:47, 7 May 2020 (UTC)

Rollback in Kinetic energy

Related to your rollback of changes in the page Kinetic energy. The addition doesn't need references because it contains only text already present in the page, the change was only a reorganization. I will not retry the edition but could be you, as the one who rollback it, should take care of solve the problem in the original page: the page starts by a textual definition of the kinetic energy (energy to provide velocity) but the first expression that appears is mv^2/2, an expression that is not the definition. Worst, is an expression valid only in Newtonian mechanics. The first expression of the page should be the formulation of the definition (integral of v * dp ). In this way, the remainder paragraphs shows the different expressions of the generic definition in the different paradigms: newtonian, sr, gr, ... . I know that changes in page about very basic concepts are near than ever rejected. But, in this case, the lack of the formulation of the definition is a problem that should be fixed. — Preceding unsigned comment added by 88.6.181.134 (talk • contribs) 19:15, 9 May 2020 (UTC)

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See wp:BURDEN. - DVdm (talk) 22:29, 9 May 2020 (UTC)

Precious anniversary

Precious

Two years!

--Gerda Arendt (talk) 06:34, 11 May 2020 (UTC)

A barnstar for you!

	The Barnstar of Good Humor
	I would like to appreciate your efforts and I apologise for my mistake. I was actually unaware of the fact that examples are already given in the topic "Acceleration" and I promise you that I will next time read the article completely. I will also make sure that this mistake does not get repeated. Thank you. Dhruval (talk) 08:15, 14 May 2020 (UTC)

Indicated value not supported by current citation

Hi, I edited the page because the value of H_0 indicated in the paragraph is not the same as the one in the source. So either (a) the citation has to be changed to one that supports the indicated value or (b) the value has to be changed to reflect what is in the cited source. I attempted to do (b). Cheers Moutmoutosaure (talk) 10:41, 18 May 2020 (UTC)

@Moutmoutosaure: as I said in my edit summary, the abstract of the cited source ([5]) says "Here, we report an improved measurement \(H_0 = 70.3_{ - 5.0}^{ + 5.3}\". I think that this is the value that we should cite. Cheers. - DVdm (talk) 11:46, 18 May 2020 (UTC)

Why source is poor

Hi, I added a link to a color-coded derivation of quantities relevant to the Atwood machine which also indicates Newton's 3rd Law more explicitly. You indicated that this new content was poorly sourced. Ruling out the possibility of the material being unsourced, the link you kindly provided to unsourced or poorly sourced material does not contain the string "poorly". Is there a glaringly obvious mistake in the derivation? Please advise. Regards, bjnartowt0. — Preceding unsigned comment added by Bjnartowt0 (talk • contribs) 14:18, 20 May 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

@Bjnartowt0: Hi. Please a have careful look at our policy regarding wp:reliable sources. The source that you are pushing here does not qualify. - DVdm (talk) 14:25, 20 May 2020 (UTC)

@DVdm: Hi. The source that I am using was written by me. While I strongly dislike arguing from authority and credentials, I suppose it is necessary to make a case from them when anyone can edit Wikipedia. I have a PhD in physics from an accredited university, and have published peer-reviewed papers. If you want proof of this, please let me know if it is possible to give the proof via some sort of private messaging. I feel that I have some unique things to present about problem-solving and derivations. They could use some cleaning up, and I would appreciate being free to do that. One of the unique things I hope to present about problem-solving includes use of color. Please visit the problems solved at stemexs.org to see that blue is used for knowns/givens, red is used for unknowns, and green is used for intermediary variables (neither given nor the final unknown being solved for). Current Wikipedia syntax has spillover of the color-command into other symbols in equations (e.g., $\color {red}{F}\color {black}{=}\color {blue}{m}\color {green}{a}$ requires explicit use of the command "\color"{black}{=}" on the equals sign, else you get $\color {red}{F}=\color {blue}{m}\color {green}{a}$). It is easier to leave everything in black (which is standard anyway) and link to my webpage where the colors are correct (which is non-standard, but nevertheless more informative). If you continue to object, Wikipedia's physics derivations can stay as they are. ~~~~ — Preceding unsigned comment added by Bjnartowt0 (talk • contribs) 13:32, 21 May 2020 (UTC)

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Ha, the source was written by you. See wp:COI.

The reason why such sources are not considered reliable, is that anyone can create websites. The value of such websites can only be establshed when they are themselves used as wp:secondary sources. If indeed your website has any value as a source for wikipedia, it will surely be referenced and quoted in the established literature. Before that is the case, it cannot be used as a source here. Give it a few years... - DVdm (talk) 13:40, 21 May 2020 (UTC)

I reluctantly defer, although not without some understanding of the issues I believe you are trying to address with policy. I will work on making my website reputable, and encourage others to add it as a citation in order to prevent a conflict of interest.~~~~ — Preceding unsigned comment added by Bjnartowt0 (talk • contribs) 15:43, 21 May 2020 (UTC)

(Please sign all your talk page messages with four tildes (~~~~) and indent the messages as outlined in wp:THREAD and wp:INDENT — See Help:Using talk pages.)

@Bjnartowt0: Yes, that's how Wikipedia works, but do not go for so-called wp:meatpuppets, i.o.w. do not start asking others to cite your webpage here on Wikipedia. That will not work, and your site will end up wp:blacklisted . - DVdm (talk) 15:53, 21 May 2020 (UTC)

Gamma function edits

Thank you for removing my edit. I just noticed the term 'translated'.Your Local Math Geekd (talk) 20:40, 21 May 2020 (UTC)

Removing external links

I just had external links removed from a page for basically no clear reason. Years ago I would add the very same links to an info database and they were not removed. I just wish this type of action would not happen here. It limits the users' access to useful data. SourceCodeX (talk) 13:45, 26 May 2020 (UTC)

@SourceCodeX: as I said in my edit summary ([6]) and on your talk page, please have a look at wp:ELNO item 11: "Blogs, personal web pages and most fansites (negative ones included), except those written by a recognized authority." I really like the webpage, but it's no good for Wikipedia. Alas. - DVdm (talk) 13:50, 26 May 2020 (UTC)

The external links removed were to a database of finely written music reviews. Writers not only contributed there but their reviews were featured on allaboutjazz.com and were paid reviewers for allmusic.com. This is not a fan site but holds stellar reviews of many genres by music experts and they are recording musicians as well. Users of Wikipedia would appreciate that kind of information at the links removed. Why hasn't anyone here removed Al Garcia's link on Jazz Fusion which blatantly seeks sales of his own music? Please explain that. The links you removed were contributions by recognized authors of the genre. We were paid for our knowledge but Wikipedia members seem to see otherwise. I guess I am not a recognized member of the editing "club" here, which explains everything. SourceCodeX (talk) 14:07, 26 May 2020 (UTC)

See wp:otherstuffexists. It's not because something (possibly bad) is done in some articles, that it can also be done in yet another article. If it has survived in the other articles, it probably was by wp:CONSENSUS, so if you would like to undo it in some other article, the best place to go is the article talk page, and propose to undo it there. For your speciific addition of the website in these two articles, there clearly is no consensus (yet). If you would really really really like to add an external link to that site, the place to go is the article talk page Talk: Mahavishnu Orchestra (and later perhaps also Talk:Jazz fusion) and propose to add the link to the external links section. You can put a reference to this section here (User talk:DVdm#Removing external links). Good luck. - DVdm (talk) 15:33, 26 May 2020 (UTC)

Dawkins

Hey mate you left a warning on my page. I understand the issue but i have received no discussion from the individual reverting my edits. No one else has objected, to the objective facts i have included.

As I am the one trying to engage and not the one reverting, can I ask why you have chosen to report me like this? — Preceding unsigned comment added by Permareperwiki1664 (talk • contribs) 15:13, 28 May 2020 (UTC)

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@Permareperwiki1664: I have not reported you. I have warned you. Getting reported and likely blocked for edit warring is what will happen next. What you need is wp:CONSENSUS on the article talk page. See wp:NOCONSENSUS: "In discussions of proposals to add, modify or remove material in articles, a lack of consensus commonly results in retaining the version of the article as it was prior to the proposal or bold edit." - DVdm (talk) 15:22, 28 May 2020 (UTC)

Coveriance

My statement on Covariance was correct. Covariance has no physical meaning. This is not debatable. I will keep removing your statement as it is clearly false. I suggest that you read this paper by:

J. D Norton https://www.pitt.edu/~jdnorton/jdnorton.html

http://www.kevinaylward.co.uk/gr/covariance_relativity.pdf

J. D. Norton has a Ph.D. in The History Of Relativity.

My own summary of what the POR is also here

http://www.kevinaylward.co.uk/gr/postulate1/postulate1.html — Preceding unsigned comment added by Kevin aylward (talk • contribs) 06:03, 4 June 2020 (UTC)

Please put new talk page messages at the bottom of talk pages and sign your messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

@Kevin aylward: Our own books and articles and websites don't count as wp:reliable sources. Our own credentials are of no importance. wp:Original research, even when based on proper sources, is not allowed on Wikipedia.

If an edit of yours ([7]) is reverted ([8]), then you should go to the talk page and, with reliable sources at hand to directly support the change, propose to the other editors what you want to do, and try to get a wp:CONSENSUS. See wp:BRD. If you can't get consensus, then nothing changes to the article —see wp:NOCONSENSUS. wp:Edit warring will get you blocked. - DVdm (talk) 08:56, 4 June 2020 (UTC)

One could well do without the condescending attitude mate. I am well aware of wikki policies. The reference to my article was to provide a deeper background to the issue in the event that individuals were unable to understand the clear refutation, by experts, of the claims made in the article. The actual authority for my statement was clearly that of one of the leading experts on the History of Relativity. The pdf link is an article written by Norton, not me. Norton goes into explicit depth as to what Covariance is, and why it is often confused, with detailed references to noted mathematicians that explain the point in detail. It is not debatable. That is, any set of equations may be put in Covariant form. Covariance is not a POR, and the statement that the POR is a statement about the form of equations is false. Period.

Although, as noted by Norton, Einstein was confused, Einstein still stated this:

Special principle of relativity: If a system of coordinates K is chosen so that, in relation to it, physical laws hold good in their simplest form, the same laws hold good in relation to any other system of coordinates K' moving in uniform translation relatively to K.

— Albert Einstein: The Foundation of the General Theory of Relativity, Part A, §1

Is not equivalent to:

“the requirement that the equations describing the laws of physics have the same form in all admissible frames of reference.”

This should be trivially obvious. One is a statement on real physics, one is a statement on mathematically formulism.

Kevin Aylward 12:36, 10 June 2020 (UTC) — Preceding unsigned comment added by Kevin aylward (talk • contribs)

Again, please sign your talk page messages with four tildes (~~~~) — see Help:Talk pages#Identifying yourself.

I also pulled your above comment out of mine — see Help:Talk pages#Replying to an existing thread: "Add your comment below the last entry in the discussion. If you want to respond to a specific comment, you can place your response directly below it." You placed your comment in the middle of mine.

If you find my warning about wp:consensus and wp:edit warring condescending, you better read the policies and guidelines again. A comment like your "I will keep removing your statement as it is clearly false" will get you blocked in no time. - DVdm (talk) 14:01, 10 June 2020 (UTC)

You can still keep you opinions to your self mate. They are worthless.

I suggest that you read the Wikki article on Kretschmann, of which I have had no part off.

https://en.wikipedia.org/wiki/Erich_Kretschmann

You are supporting a view that is proven false. To wit: formulating theories with equations having the same form in all co-ordinate systems is not a POR, neither does it have any physical meaning. So I suggest that you get your head out of your arse because you are only embarrassing yourself. — Preceding unsigned comment added by Kevin aylward (talk • contribs) 16:02, 12 June 2020 (UTC)

Sign all your talk page messages with four tildes (~~~~) and indent the messages as outlined in wp:THREAD and wp:INDENT — See Help:Using talk pages.

Formal personal attack warning on your talk page: [9]. - DVdm (talk) 16:43, 12 June 2020 (UTC)

Newton's law of universal gravitation

How is my reason to remove the content not relevant? Problematic statement, "Newton's theory of gravitation requires that the gravitational force be transmitted instantaneously. Given the classical assumptions of the nature of space and time before the development of general relativity, a significant propagation delay in gravity leads to unstable planetary and stellar orbits."

First problem: no reliable source to back up this claim that it is indeed a theoretical concern of Newton's law.

Second problem: how is instantaneous force a concern anymore with modern physics? Literally, all 4 known fundamental forces in physics happen instantly. Simply put, this concern here is outdated and no longer is a concern. 14.169.171.239 (talk) 18:50, 12 June 2020 (UTC)

But this is not in the context of moden physics. It says "Given the classical assumptions of the nature of space and time before the development of general relativity."

Anyway, I think it's best to take this to article talk page. Here we can discuss user related matters and other non-article related topics. - DVdm (talk) 20:36, 12 June 2020 (UTC)

.

The Institute for Statecraft is a GONGO

The Institute for Statecraft is a government-organized Non-governmental Organization just like the American GONGO National Endowment for Democracy.--88.66.151.168 (talk) 17:24, 16 June 2020 (UTC)

New Page Reviewer newsletter June 2020

Hello DVdm,

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Modern flat Earth societies‎

Yes. Also, those works are broadly geocentric, anyway. Thanks for the correct edit action. Regards, El_C 20:45, 21 June 2020 (UTC)

Draft Article

Hi, i have been created a page but it turned to draft and it has been declined. However there is a version of german. Also there are lots of sources. Can you check? Draft:Şanışer Baran Ahmet (talk) 07:16, 25 June 2020 (UTC)

I'm afraid I can't help there. Best to go to the deletion discussion. Good luck! - DVdm (talk) 09:17, 25 June 2020 (UTC)

Photoelectric effect edit

Hey. I noticed you reverted the metal/material edit Photoelectric effect. Photoemission is actually possible (I've done it myself), from any conductor, no matter how bad (metal, semimetal, semiconductor, superconductor), so replacing metal with material wasn't that bad. Even insulators will photoemit, but the electrons will be discouraged from leaving the surface of the material due to charging. Ponor (talk) 10:05, 3 July 2020 (UTC)

Hi Ponor, yes, with very high frequency light it's possible, but in metals it is much more common — see, for instance this source. My revert was mostly aimed at the edit symmary "Fixed possible typo", changing the correct "metal" into "meterial", not "material". A pretty sloppy edit that was... - DVdm (talk) 10:50, 3 July 2020 (UTC)

Oh I see. Never mind. I'll be working on this article (PE is my specialty) and I'll see what to do with it. We start with 'material', then limit ourselves to metals, and switch back and forth. Btw, a small gap semiconductor wouldn't need that much higher light freq. Photoemission from metals is more of a historical thing. Cheers! Ponor (talk) 11:28, 3 July 2020 (UTC)

Special relativity edits

I have noticed that you have sent this warning only for me but not for the other editor. I think that it is not fair. I will complain your behavior to senior advisory board. It seems to me that you conduct biased editing. I would like to note, that my edits are based on primary source - 1905 A. Einstein article. As soon as tomorrow I will start formal disputer resolution. Cheers! --185.71.245.255 (talk) 21:53, 5 July 2020 (UTC)

Since I am a novice here, could you please to inform me, what should I do so as to write a complain? I insist, that these words that relativity of simultaneity is experimentally proven concept be removed from the article --185.71.245.255 (talk) 21:56, 5 July 2020 (UTC)

If these words will be removed, I will refrain from complaints; otherwise I will be forced to release some smell and all my actions will be recorded in the Wikipedia edit history --185.71.245.255 (talk) 22:03, 5 July 2020 (UTC)

See wp:BRD. You need go to the article talk page and carefully explain what you have in mind, based on and backed by proper wp:reliable sources, which In this case probably means textbook sources. Next time you make this edit without establishing a solid wp:CONSENSUS for it, you'll be blocked. Also, making threats will get you nowhere. On the contrary, they will get you out of here before you can say WOW. - DVdm (talk) 22:07, 5 July 2020 (UTC)

This is the excerpt from reliable primary source: A. Einstein's 1905 paper - If at the point A of space there is a clock, an observer at A can determine the time values of events in the immediate proximity of A by finding the positions of the hands which are simultaneous with these events. If there is at the point B of space another clock in all respects resembling the one at A, it is possible for an observer at B to determine the time values of events in the immediate neighbourhood of B. But it is not possible without further assumption to compare, in respect of time, an event at A with an event at B. We have so far defined only an " A time " and a " B time." We have not defined a common " time " for A and B, for the latter cannot be defined at all unless we establish by definition that the " time " required by light to travel from A to B equals the " time" it requires to travel from B to A. 185.71.245.255 (talk) 22:08, 5 July 2020 (UTC)

It seems that you treat me

On the contrary, they will get you out of here before you can say WOW .Please note that you tone is far away from being polite. I think it directly violates some of Wikipedia policies. Could you please refrain speaking to me this way. I will complain your behavior to senior advisory board. Also, please revert your edits and remove words that relativity of simultaneity is experimentally proven concept.185.71.245.255 (talk) 22:13, 5 July 2020 (UTC)

Article talk page. But first familiarise yourself with wp:SYNTHESIS and wp:No original research. Otherwise you will be wasting your time on Wikipedia.

And I am not threatening you. I am warning you about what will happen if you make treats about "releasing some smell". Trust me, that is not a good idea. - DVdm (talk) 22:17, 5 July 2020 (UTC)

Thank you very much for you kind advise to go to the talk page. But, it seems to me it is better to start dispute resolution; I have clearly provided primary source and do not understand why do you violate WP:PRIMARY and WP:NPOV. On the contrary, they will get you out of here before you can say WOW. That apparently violates WP:PA. Please note that WP:CIV policy states: Be careful with user warning templates. Be careful about issuing templated messages to editors you're currently involved in a dispute with, and exercise caution when using templated messages for newcomers (see Wikipedia:Please do not bite the newcomers). Consider using a personal message instead of, or in addition to, the templated message.

Please also note, that another user started edit war; so your message should be sent to that user also. Hence, your behavior clearly violates WP:NPOV. Best personal regards, --185.71.245.255 (talk) 22:39, 5 July 2020 (UTC)

@185.71.245.255: It appears you do not have an understanding of how Wikipedia works and what special relativity is. Issuing threats and making bizarre statements will not get you anywhere. (talk) 22:59, 5 July 2020 (UTC)

Attention editors DVdm and Nerd271. Please note that the source that you have added neither primary, not reliable. Actually it doesn't matter, since the source clearly says that "no specially designed experiment have been carried out to test relativity of simultaneity". Hence it cannot be used as a source. Indeed, as soon as one way speed of light even in principle cannot be measured prior to certain clock synchronization scheme the concept of relative simultaneity cannot be experimentally confirmed . Please familiarize yourself with wp:SYNTHESIS and wp:No original research. Primary source WP:PRIMARYis the celebrated A. Einstein's 1905 article "On the electrodynamics of moving bodies" which clearly indicates that distant simultaneity is conventional. The article must be in accordance with WP:NPOV. Please familiarize yourself with the WP:PRIMARY A. Einstein's 1905 article "On the electrodynamics of moving bodies". Let's discuss it on the article's talk page some days later or should you agree with my note and WP:PRIMARY just delete that claim that Relativity of Simultaneity can be experimentally confirmed, this way we can avoid boring dispute resolutions. I trust that together we are on the right track to improve the article. Cheers! It should be noted that while the article is good. this claim is not supported by any reliable source and must be deleted 84.15.180.53 (talk) 20:59, 6 July 2020 (UTC)

I agree with user Nerd271 that it appears that you do not have an understanding of how Wikipedia works. Of course that is to be expected if indeed, as you say, you are "a novice here". You seem to have got it completely backwards. Wikipedia does not need wp:primary sources. Wikipedia needs wp:secondary sources. I added one that explicitly backs the content. And by the way, you cannot just remove properly sourced content, basing yourself on your wp:original research and wp:synthesis of some sources, specially not of primary ones. Wikipedia does not work that way. What you are facing now, is wp:NOCONSENSUS, and as you can verify, "In discussions of proposals to add, modify or remove material in articles, a lack of consensus commonly results in retaining the version of the article as it was prior to the proposal or bold edit." - DVdm (talk) 21:53, 6 July 2020 (UTC)

Edit of Imaginary unit

Hi DVdm.

My change is consistent with the current source. That's because the unchanged article misinterprets the source. The source does NOT say that that a and b must both be positive. I know this because I own a copy of the source and looked it up. The source uses an example from which it's clear that a and b cannot both be negative. This is very different to inferring that a and b must therefore both be positive, which is what the article currently does.

It's trivial to see that one of a and b can be negative: Sqrt[-4] = Sqrt[4 x -1] = Sqrt[4] x Sqrt[-1] = 2i is quite correct.

So my edit fixes two mistakes in the article: An incorrect mathematical statement and the incorrect use of a source. I suggest you refer to the source yourself and check this.

Kind regards.

Incredible. Dr Incredible (talk) 07:13, 6 July 2020 (UTC)

@Dr Incredible: ok, go ahead and feel free to refix, mentioning the source in your edit summary. Cheers. - DVdm (talk) 07:18, 6 July 2020 (UTC)

@DVdm: Actually I've re-considered my position. I still think the source is being misinterpreted, but the mathematical statement is correct: a and b must both be positive. Sqrt[-4] = Sqrt[4 x -1] = Sqrt[4] x Sqrt[-1] = 2i is not correct, it should equal pm 2i. Otherwise:

Sqrt[-4] = Sqrt[4/-1] = Sqrt[4]/Sqrt[-1] = 2/i = - 2i and Sqrt[-4] = Sqrt[-4/1] = Sqrt[-4]/Sqrt[1] = 2i which is inconsistent.

So I will not currently be making any changes, but will keep an eye open for a more explicit source.

Kind regards.

Incredible Dr Incredible (talk) 17:42, 6 July 2020 (UTC)

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

@Dr Incredible: hmm; hold it with that pm 2i there. Sqrt(4) = 2 and Sqrt(-1) is actualy meaningless, but if we write it nevertheless, then it equals i, (not -i, and not pm i). Sqrt is supposed to always give the principal value. See also the last sentence of Imaginary unit#Proper use. There is a reason why we don't write sqrt(-1). This has been discussed on the talk pages many times. The current version has been pretty stable for quite a while, and seems to have earned a long standing consensus now, so I propose to keep the article the way it is now. Let's keep it clear and safe. - DVdm (talk) 17:57, 6 July 2020 (UTC)

@DVdm: The only change I'd consider making would be a more appropriate source that explicitly states what is stated in the article.

Re: Sqrt(-1) = i. OK, you're making a distinction between Sqrt and sqrt. Of course one can always define Sqrt to mean the principle square root. Otherwise $-1=i^{2}$ gives us ${\sqrt {-1}}=\pm i$ and ${\sqrt {}}$ must be explicitly defined as giving the principle value before ${\sqrt {-1}}=i$ is correct. For real numbers we decide early on that ${\sqrt {4}}=2$, the positive root. Once we get to complex numbers, ${\sqrt {4}}=2$ is ambiguous, and we either have to live with that ambiguity or introduce such explicit definitions.

Anyway, I have no debate against your proposal except to say that a better (and non-circular) source (that gives a clear and explicit statement which is not open to interpretation) is needed IMHO. Such a source seems remarkably scarce.

Kind regards.

Incredible Dr Incredible (talk) 23:26, 6 July 2020 (UTC)

Yep, a better (or an additional) source will certainly do no harm . I'll also try to find one tomorrow. Cheers - DVdm (talk) 23:36, 6 July 2020 (UTC)

 Done @Dr Incredible: See [10]

References

Cast in concrete now - DVdm (talk) 09:53, 7 July 2020 (UTC)

Nice try, DVdm. But there's a snag: Those references are only dealing with real numbers (unless I've missed something), simplification of roots of negative numbers such as ${\sqrt {-27}}$ are not considered. What's needed is either a reference or a proof that says ${\sqrt {a\times b}}={\sqrt {a}}\times {\sqrt {b}}$ is valid for a,b > 0 or one of a,b < 0 but is not valid for both a,b < 0.

The rule ${\sqrt {\frac {a}{b}}}={\frac {\sqrt {a}}{\sqrt {b}}}$ should also be mentioned because the restrictions on its validity are different: Valid only for both a,b > 0.

(In both rules the restrictions are needed to avoid contradictions).

Furthemore, when a,b > 0 the case ${\sqrt {-{\frac {a}{b}}}}$ must be treated as ${\sqrt {-1\times {\frac {a}{b}}}}$ (for the aforementioned reason).

So this part of the article still needs some work.

I'd be happy to make the required changes, but I don't think any changes to the content can be made until a reference (or proof) that explicitly covers all of the above can be found. As I said earlier, references seem rather scarce.

Incredible. Dr Incredible (talk) 10:55, 9 July 2020 (UTC)

Let's not forget that the section Imaginary unit#Proper use is about avoiding making mistakes. Sure, perhaps the mistakes can be avoided by allowing still one of a,b < 0, but they can surely be avoided by demanding both a,b > 0. The latter is now explicitly supported by the sources. Clearly in both cases the calculation rules ${\sqrt {a}}\cdot {\sqrt {b}}={\sqrt {a\cdot b}}$ and ${\frac {\sqrt {a}}{\sqrt {b}}}={\sqrt {\frac {a}{b}}}$ are abused, and we can avoid the abuse by always demanding both a,b > 0 (and thus also only real). And of course, if we do not write ${\sqrt {-1}}$ to begin with, but rather i, we cannot make the mistake. If we never, ever write nonsense like ${\sqrt {-27}}$, we won't make mistakes. That's why we write $i{\sqrt {27}}$. I don't think that part of the article needs work, as it's there to give a warning and a clear, sourced recipe for how to avoid making mistakes. - DVdm (talk) 11:54, 9 July 2020 (UTC)

@Dr Incredible: FWIW, I have added another source, backing the entire section: [11]

References

The pages 30-34 should cast it in reinforced concrete - DVdm (talk) 15:33, 9 July 2020 (UTC)

Yes, I found that source too. I agree that its suggestion is the simplest. But it's more *ahem* complex than that: There are many secondary school textbooks (in Australia, for example) that explicitly set questions like "simplify ${\sqrt {-27}}$" etc. Even worse, these questions are set at the very start of the introduction to complex numbers, so the idea of the principle square root cannot even be meaningfully introduced (as an analogue to the conventional 'positive square root'). So the mistakes can't be avoided simply by saying to only use when a,b > 0. Otherwise you have Wikipedia butting heads with the secondary school textbooks of an entire country .... What's needed is a clear statement of exactly when those rules can be validly used. There's no doubt that something like ${\sqrt {-27}}=3{\sqrt {3}}i$ can make sense when things are properly defined or/and the rules are clear. The problem is that many secondary school textbooks are hopelessly wrong in how they explain this stuff (and so cannot be used as sources) and university level textbooks avoid the question altogether either by omission or by giving the advice to only use when a,b > 0 (and so are not useful sources).

The more I think about it, the more I think that the justification has to come via examples:

${\sqrt {27}}=3{\sqrt {3}}$ so (by the convention of using the 'positive square root') valid to use when a,b > 0,

${\sqrt {-27}}={\sqrt {-1\times 27}}=3{\sqrt {3}}i$ so valid to use (if ${\sqrt {}}$ is the analogue of the positive square root called the principle square root) when one of a,b > 0,

${\sqrt {-3\times -9}}$ leads to a contradiction so NOT valid to use (if ${\sqrt {}}$ is the analogue of the positive square root called the principle square root) when both a,b < 0.

Alternatively, the condition $-\pi <{\text{Arg}}(a)+{\text{Arg}}(b)\leq \pi$ on the principle arguments of a and b is discussed and used as a justification.

Anyway, these are my thoughts. It's only a small thing, but it looks like the Wikipedia article has the opportunity to make the definitive statement on this.

Incredible Dr Incredible (talk) 23:47, 9 July 2020 (UTC)

That reminds me of my old algebra teacher during my all-math prep year between highschool and university, the one who used to shred or rip our homeworks and tests to pieces when he couldn't discern a handwritten digit "6" from a letter "G", all in the name of care and precision. He also told us he'd do the same when he'd come across something negative (or even unspecified) under the radical sign. Even to this day, when typing ${\sqrt {-1}}$, I still feel an eerie urge to check behind me if he's there. I loved that teacher. He was one of the teachers who inspired me to decide to go for a math master's at university . DVdm (talk) 09:37, 10 July 2020 (UTC)

Cool teacher! Fair call, too. I hope he knew how you (and I'm sure many other students) felt. I bet you always calculated the discriminant first before using the quadratic formula. (But what did you do when using the cubic formula?) It's an uphill battle in Australia with many school textbooks forcing students to deal with negatives under the radical sign as part of an 'introduction' to complex numbers. There's an interesting discussion here: https://mathematicalcrap.com/2018/06/09/witch-2/#comment-3369 . And here: https://mathematicalcrap.com/2018/06/11/witch-3/#comment-3370

Incredible. Dr Incredible (talk) 10:47, 10 July 2020 (UTC)

An equation for the cycloid of the form y = f(x)

I don't have any reliable sources to cite but I've written my own demonstration of it on Desmos' graphing calculator (which can't be used as a source, of course):

${\begin{aligned}&f\left(x\right)=\sin \left(x\right)+x,\\&N=\infty \in \mathbb {N} ,E=2\pi ,\\&I\left(x\right)={\frac {E\sum _{n=1}^{N}\left\{x\geq f\left({\frac {En}{N}}\right):1,0\right\}}{N}}{\text{ (rough inverse)}},\\&f_{i}\left(x\right)=I\left(x\right)+{\frac {E\left(x-f\left(I\left(x\right)\right)\right)}{N\left(f\left(I\left(x\right)+{\frac {E}{N}}\right)-f\left(I\left(x\right)\right)\right)}}{\text{ (with linear interpolation)}},\\&f_{ip}\left(x\right)=f_{i}\left(\operatorname {mod} \left(x,E\right)\right)+E\operatorname {floor} \left({\frac {x}{E}}\right){\text{ (with repetition)}},\\&\cos \left(f_{ip}\left(x\pm \pi \right)\right)+1{\text{ (the cycloid)}}.\\\end{aligned}}$

Also, how would you integrate instead of summing? If integrated, linear interpolation wouldn't be necessary here.

I also found this: ${\frac {p(1-\cos(f^{(-1)}{\Bigl (}{\frac {2\pi x}{p}}{\Bigr )}))}{2\pi }}$given $f(x)=x-\sin(x)$ and $f^{(-1)}(x)$ is its real valued inverse.

I've tried looking up on the Internet about this but there's a lack of information, probably because of the keywords I use. I really need help with this. - AnastDunba (talk) 10:40, 12 July 2020 (UTC)

@AnastDunba: Another reason for absence of sources could be that the content is insufficiently noteworthy — see WP:NOTEWORTHY. Absence of reliable sources for some content usually implies that Wikipedia should not include it. Hope this helps a bit. Cheers. - DVdm (talk) 10:55, 12 July 2020 (UTC)

But what about $\sin \left(x\right)+x$ itself? All I've found is Kepler's equation; looking up “inverse of sin(x)+x” doesn't tell much, I come across a lot of flawed answers that doesn't help much. - AnastDunba (talk) 11:07, 12 July 2020 (UTC)

And what's this supposed to be? $f^{-1}(y)=\sum _{n=1}^{\infty }{\frac {y^{n/3}}{n!}}\lim _{\theta \to 0}\left({\frac {\mathrm {d} ^{\,n-1}}{\mathrm {d} \theta ^{\,n-1}}}\left({\frac {\theta }{\sqrt[{3}]{\theta -\sin(\theta )}}}\right)^{n}\right).$ Why the higher-order derivatives? I know that this is now unrelated to the cycloid but I'm getting confused by this. - AnastDunba (talk) 12:52, 12 July 2020 (UTC)

I guess it was just about the Kepler's equation the entire time regarding $\sin \left(x\right)+x$, sorry for bugging. -- AnastDunba (talk) 13:03, 12 July 2020 (UTC)

No problem. Happy source hunting . - DVdm (talk) 14:48, 12 July 2020 (UTC)

Notation for continued fractions

The notation I used is used on The Mathematical Functions Site from Wolfram Research (https://functions.wolfram.com). Here are examples of the usage: https://functions.wolfram.com/ElementaryFunctions/ArcTan/10/ https://functions.wolfram.com/ElementaryFunctions/Sqrt/10/ Does that count as a reliable source? A1E6 (talk) 18:58, 13 July 2020 (UTC)

Wolfram is not always reliable. A textbook source would be preferable. You can try Google books search. Happy hunting! - DVdm (talk) 19:06, 13 July 2020 (UTC)

@DVdm: But why not? A1E6 (talk) 19:48, 13 July 2020 (UTC)

I have seen it having mistakes and being removed as a source in the past. Can't name specifics at this moment. I suggest you ask at the respective article talk pages whether the other contributors would agree using it as a source - see wp:CONSENSUS. Feel free to point to this little discussion through [[User talk:DVdm#Notation for continued fractions]]. Good luck! - DVdm (talk) 21:07, 13 July 2020 (UTC)

@DVdm: I've checked over 50 books on the topic for the notation from Wolfram, and actually no book uses it. That was quite surprising for me. I will revert my edits. A1E6 (talk) 19:40, 14 July 2020 (UTC)

@A1E6: yes, in that case the notation is de-facto likely insufficienly wp:noteworthy. If indeed it were, other editors would redo or go to the article talk page. Thanks & cheers. - DVdm (talk) 08:33, 15 July 2020 (UTC)

Bad source

@DVdm: You remove my changes from https://en.wikipedia.org/w/index.php?title=Imaginary_unit&diff=968931647&oldid=968914796 - but I take this source from other wikipedia article https://en.wikipedia.org/wiki/E_(mathematical_constant)#cite_note-OConnor-5 (!!!) - can you explain what is wrong with it and fix that article which also use that source? — Preceding unsigned comment added by Kamil Kielczewski (talk • contribs) 11:33, 22 July 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

I replied on your talk page: User talk:Kamil Kielczewski#Source. - DVdm (talk) 12:11, 22 July 2020 (UTC)

My changes

Dear friend, I cannot provide a source because this logic was suggested by my father. It is mathamatically sound, but you should go over it if you wish. Also, I noticed that one of the paragraphs didn't have a proper conclusion, so I added one. Please go over it once more. Thanks Rak Laptudirm (talk) 12:59, 2 August 2020 (UTC)

Hi Rak Laptudirm, unfortunately, this does not count for Wikipedia. wp:Reliable sources are required (1) to provide a way to verify new content, and (2) to establish whether new content is noteworthy to be included. - DVdm (talk) 13:11, 2 August 2020 (UTC)

Ok, sure. Thank you for the information. Rak Laptudirm (talk) 14:40, 2 August 2020 (UTC)

My apology

I apologise for editing the Wikipedia page for "Caracal" without using a reliable source. I thought my source was reliable at the time, but I know realise that it was not. I will try to be more vigilant in the future. Roman Biggus (talk) 13:20, 17 August 2020 (UTC)

Sorry, I was trying to put them under my name

If you want the real Relativities that Garret and Stephen referred to, you need to publish my 41 years of thought experiment.

You know, the Justification for the Metric System ?

It's your loss if you don't, Ask Garret Lisi for confirmation. They are all under my IP address, I've created a username bernhard.eringa, put them all under that name if you like, the titles are true english descriptions though, up to my peers to figure out the precedences.

Sorry again.

Regards Bernhard Eringa 13 Quantum Theory PhD's hanging on the walls of the N.Z. Governments Prime Minister's Office since 1983. — Preceding unsigned comment added by 121.99.160.104 (talk) 20:30, 29 August 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

There is probably no place for this in Wikipedia. See our policy on wp:original research. You will have to seek another venue. Good luck. - DVdm (talk) 21:15, 29 August 2020 (UTC)

Note to self, see Bernhard.Eringa (talk · contribs · deleted contribs · logs · filter log · block user · block log). - DVdm (talk) 21:50, 29 August 2020 (UTC)

Full revert of an edit (derivation of a physics formula) in Elastic collision article due to lack of citation

Hi DVdm,

Re: Full revert of an edit (derivation of a physics formula) in Elastic collision article due to lack of citation (copied from my user talk page)

Thank you for the notice of lack of citation. The derivation is elementary, so it does not require a source & its validity can be verified easily. Nevertheless, citation has been added.

However, my edit should have remained but been tagged for citation. It is not appreciable that the edit was reverted in its entirety, which is disproportionate and is demotivating in participating further in Wikipedia. But, I really do appreciate that you reached out directly on my talk page, which I wish established editors would engage in more.

FYI, I may be adding to that article further re: Body assumptions; Programming; Ideal & non-ideal classical mechanics; Statistical mechanics. Will keep in mind citations and will appreciate discussion before full reverts.

Thank you,

173.206.33.141 (talk) 19:17, 2 September 2020 (UTC)

There's no need to duplicate what you wrote on your talk page. I replied there. Cheers. - DVdm (talk) 19:46, 2 September 2020 (UTC)

Inverse Trig Functions

This is getting interesting. I used Wolframalpha to verify that the log identity for arcsin holds everywhere. Also, according to Wolfram, the equality in Wiki of arccos to -i ln(z + (z^2-1)^.5) should be removed. It fails for real z > 1 or < -1 and for all z in the open second and fourth quadrants. You are apparently assuming that the arccos equality above is correct in your latest editing note. It looks to me as though either the Wiki article or Wolfram is wrong. Rickhev1 (talk) 00:46, 6 September 2020 (UTC)

@Rickhev1: See the edit summary of the revert by user A1E6. You might bring this up on the article talk page. Note that Wolframalpha is not always reliable. It has many errors, and all emails with remarks about errors are ignored, so I have given up contacting them and never use Wolfram as a source. - DVdm (talk) 08:54, 6 September 2020 (UTC)

Gravitational time dilation: circular orbits

Greetings,

I wanted to discuss the situation with the recent edits on the page in the topic. My aim (and, probably, that of the previous editor) was to make it as unambiguous as possible, what is exactly compared in the formula. The things it is intended to say, or, maybe, the time on orbiting clocks vs ones staying still at the same elevation? I remember being confused about it when I read that, and had to calculate myself to make sure.

So this is the issue I want to resolve, so that the piece serves better as an encyclopedia. And I thought that the article means by "gravitational time dilation" exactly what you seem to call "gravitational potential TD": for example "Gravitational time dilation is a _form_ of time dilation,.. by observers situated at varying distances from a gravitating mass. The lower the gravitational potential, the slower time passes..." seems to be speaking specifically of "potential TD", not just "any time discrepancy in GR".

But I don't want to argue definitions. Since in the case at hand (circular orbits in Schwarzschild metric) the "potential" and "velocity" TD's separate perfectly well, and thus the reader might be confused (as I was, to an extend) about which combination of those is presented, I think it would be beneficial to state it more clearly and fully, like "from above, the TD for stationary observer at a given altitude is /formula/; the body on a circular orbit passes that observer (in their coords) at the speed /formula/, adding velocity time dilation, so the total TD on a circular orbit (relative to the distant observer) amounts to /pot TD/*/velocity TD/=/formula/" (but, I hope less wordy:). What do you think?

Also, I am not sure why stressing "one orbit" is necessary here, but that's a minor point.

Nice user page, BTW.

L3erdnik (talk) 07:04, 25 September 2020 (UTC)

@L3erdnik: Hi there, thanks!

In this case the /velocity TD/ formula is not given. We know from Taylor and Wheeler (exercise 4-3A and 4-3D) that the satellite speed as measured by a (hanging) shell observer is vs = sqrt(1/2 rs/r) and as measured by the far-away observer vf = sqrt( 1/2 rs/(r-rs) ). The latter would produce /velocity TD/ = sqrt( 1 - vf^2 ). So, with /pot TD/ = sqrt( 1 - rs/r), doing this multiplication /pot TD/*/velocity TD/ would not produce sqrt( 1 - 3/2 rs/r ).

Before doing anyting of this kind, in order to avoid stritcly forbidden wp:original research, we'd need a source that explictly connects the 3 formulae.

I have removed the "one orbit" clause ([12]). It's not needed and not in the sources.

I think that further discussion about this should go to the article talk page. Cheers! - DVdm (talk) 09:32, 25 September 2020 (UTC)

Gamma function

"x equals"

or

"x is equal to"

are correct in English.

but

"x equal to" is grammatically incorrect. It needs "is" or "s".

Thanks, Hooman Mallahzadeh (talk) 14:20, 27 September 2020 (UTC)

@Hooman Mallahzadeh: I think you missed the context. This is the complete original sentence:

"A more restrictive property than satisfying the above interpolation is to satisfy the recurrence relation defining a translated version of the factorial function,

$f(1)=1,$

$f(x+1)=xf(x),$

for x equal to any positive real number.

Your change ([13]) assumed that "for" meant "because" and in that case the "is" is needed.

Here the "equal to" is a property of x for which the equations apply. This is a very common mathematics sentence construction, and grammatically 100% correct. You changed the meaning and left an incorrect statement. That is why I changed ([14]) it into this:

"A more restrictive property than satisfying the above interpolation is to satisfy the recurrence relation defining a translated version of the factorial function,

$f(1)=1,$

$f(x+1)=xf(x),$

for any positive real number x.

This way the "for" cannot be misunderstood. Hope this helps. DVdm (talk) 14:57, 27 September 2020 (UTC)

By the way, Hooman Mallahzadeh, there is a glaring grammatical error in your edit summary "Grammatically correction": That should either be "Grammatical correction" or "Grammatically corrected". Adverbs go with verbs, adjectives and other things, but never with nouns. It looks like you are not well acquainted with English grammar, so please try to avoid making grammatical "corrections" that are in fact grammatical errors. Thanks. - DVdm (talk) 15:44, 27 September 2020 (UTC)

@DVdm: Thank you for your reply and helpful guidance. — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:02, 27 September 2020 (UTC)

@DVdm: But I think "is" is required but it is implicitly considered in such sentences as a tradition.

Am I wrong?Hooman Mallahzadeh (talk) 16:06, 27 September 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

Yes, you are wrong—see my explanation above. By the way, here I undid another grammatical error that you made here. "The rich" is plural. And here you made another error. So again, please do not make grammatical corrections on the English Wikipedia anymore—see wp:CIR. Perhaps it's best to only make such changes in the Wikipedia of your own language. Thanks. - DVdm (talk) 16:12, 27 September 2020 (UTC)

@DVdm: See my edit here

https://en.wikipedia.org/wiki/Template:Tmath

is not wrong. Please make more attention. Hooman Mallahzadeh (talk) 16:26, 27 September 2020 (UTC)

When you make an edit that gets reverted, you best go to the talk page of the template and discuss with the other editors. See wp:BRD. Good luck. - DVdm (talk) 16:30, 27 September 2020 (UTC)

Where are you from my friend? — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:33, 27 September 2020 (UTC)

I am a computer engineer in middle east. — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:33, 27 September 2020 (UTC)

I think we should be more friendly together. — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:34, 27 September 2020 (UTC)

I love statistics and mathematics, in addition to computer. — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:35, 27 September 2020 (UTC)

And I'm a researcher in the field of "Natural Language Processing". — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:37, 27 September 2020 (UTC)

I encounter Gamma function in this field in the Rank-size distribution, in the field of linguistics. — Preceding unsigned comment added by Hooman Mallahzadeh (talk • contribs) 16:38, 27 September 2020 (UTC)

Gamma (the letter)

Just out of curiosity, why did you revert this (which I agree with) but then turn around and revert this, which returns the gamma back to its original form? Seems somewhat contradictory. Primefac (talk) 11:45, 30 September 2020 (UTC) (please ping on reply)

@Primefac: ah, sorry. I noticed these silly tau-edits by anon 176.88.94.163, and then reverted most of their other edits without paying much attention. Perhaps I reverted one too many. Feel free to amend. Cheers and thanks. - DVdm (talk) 12:37, 30 September 2020 (UTC)

I know what that's like! Thanks. Primefac (talk) 12:55, 30 September 2020 (UTC)

Communication

If you want to discuss something with me, talk to me directly, using your own words. Repeatedly leaving templates is just rude. 46.208.152.81 (talk) 13:56, 4 October 2020 (UTC)

See Block log - DVdm (talk) 15:46, 4 October 2020 (UTC)

Frames & Coordinates & Covariance

Ho humm….

Consider bits and bobs in a real, physical frame, such as a bus that is moving inertially, that is a point *locked* to the bus motion is expressed by X’=X-vt wrt to a reference observer. One performs a coordinate transformation such that the point X’’ is now described by a rotating coordinate system X’’=a.sin(w.X’), notwithstanding that the bus is *still* moving *inertially* by *definition*, only the coordinate system has changed.

Now… explain, in this universe, why SR no longer applies to the bus, even though the bus is still traveling inertially, and one has simply performed a mathematical change of variables to an accelerating coordinate system?

Thus, whether or not a system is subject to the laws of SR is only a matter of whether or not the system is inertial, not what coordinate system is used to describe it, accelerating or otherwise. coordinate systems have no physical meaning whatsoever. This is trivially obvious.

Your problem mate, is that that you need to think for yourself and to not parrot off that which you don’t understand. Coordinate systems are not reference frames. Its truly that simple.

J D Norton (PHD in History of General Relativity) gives a full detailed account of Einstein’s confusion on coordinate systems and Covariance.

http://www.pitt.edu/~jdnorton/jdnorton.html

In particular, on Covariance: "General Covariance and the Foundations of General Relativity: Eight Decades of Dispute,

http://www.pitt.edu/~jdnorton/papers/decades.pdf Kevin aylward (talk) 11:01, 17 October 2020 (UTC)

Double-slit experiment

The equation in the text is normalised (incl. pi's in the sinc-function), so don't refer to it as an unnormalised function. This is plain math. No citation needed. Just watch the sinc-function-article. So yes, you were wrong undoing my edit. — Preceding unsigned comment added by Koitus~nlwiki (talk • contribs) 22:49, 6 November 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

Hi Koitus~nlwiki, the article said: sinc(x) = sin(x)/x, which, as you can see in the Sinc article, is correct. With these edits, you changed it to sinc(pi.x) = sin(pi.x)/pi.x which, for two reasons is not correct. First, you should have written sinc(pi.x) = sin(pi.x)/(pi.x) — see the parentheses in the denominator. Second, the Sinc article says that the normalized sinc function is defined as sinc(x) = sin(pi.x)/(pi.x) — see the absence of pi in the argument of sinc. Hope this helps . - DVdm (talk) 10:01, 7 November 2020 (UTC)

Notice of Dispute resolution noticeboard discussion

This message is being sent to let you know of a discussion at the Wikipedia:Dispute resolution noticeboard regarding a content dispute discussion you may have participated in. Content disputes can hold up article development and make editing difficult for editors. You are not required to participate, but you are both invited and encouraged to help this dispute come to a resolution.

Please join us to help form a consensus. Thank you!

Wikipedia:Dispute resolution noticeboard#Time dilation --84.120.7.178 (talk) 00:05, 15 October 2020 (UTC)

Follow-up at RS noticeboard. - DVdm (talk) 10:04, 15 November 2020 (UTC)

Requesting input on Introduction to thermodynamic entropy RfC

Hello! I am reaching out to several experienced Wikipedians regarding an impasse that is being reached in an RfC on the article Introduction to thermodynamic entropy, formerly titled Introduction to entropy.

In my opinion, the discussion is being dominated by physicist–editors who do not like the introduction as it currently stands (15 November 2020) or numerous recent attempts at an introduction that is friendly and accessible to the lay reader. These editors seek a rigorous introduction, the suggestions for which have been very unpalatable to me as a science communicator (e.g., "Entropy is a quantitative guide to the unavailability, due to inevitable natural inefficiency, of the intrinsic energy of a body of matter or radiation, for thermodynamic work that can be harnessed to do mechanical work outside the body"). The article has a long history of complaints about it being overly technical, and matters are only getting worse.

On the Talk page you will find several long sections on the RfC. If you wish to comment, perhaps start a new section if another editor has not already done so. Thank you for your time. -Jordgette [talk] 18:18, 15 November 2020 (UTC)

Why have you chosen to bully me, and what is your authority to do so?

Why are you making false accusations against me? SlyGuyFox (talk) 20:28, 20 November 2020 (UTC)

@SlyGuyFox: Aw. My mistake, and my apologies. I totally misread the intention of your edits. I'll undo my edits where you haven't done so yet. - DVdm (talk) 20:31, 20 November 2020 (UTC)

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Why did you remove my External Links for Relative velocity and Velocity-addition formula

Hello DVdm, I would appreciate knowing why the external link Einstein Velocity Addition/Subtraction Formula for Special Relativity were removed from articles Relative velocity and Velocity-addition formula. I must mention that I am the owner of this external website and author of the article. The Wikipedia Articles on Relative velocity and Velocity-addition formula although very elaborate are somewhat confusing to a first time learner of the subject as the same formulae are mentioned in drastically different manner in the 2 articles. The link that I have provided tries to simplify the presentation of formulae related to Einstein Velocity Addition, and I hope you will re-add them unless you can give me a good reason for not doing the same.

Thanks Aruphore (talk) 04:31, 26 November 2020 (UTC)

@Aruphore: Hi, on the talk page of your ip (User talk:122.177.29.82), I pointed to wp:ELNO, item #11 for links to be avoided, which says: "Blogs, personal web pages and most fansites (negative ones included), except those written by a recognized authority." It does not look like this anonymous website is written by a recognized authority, so it does not belong in Wikipedia. In the section wp:ELYES, you can find out which kind of external links are welcome here. Hope this helps. - DVdm (talk) 10:58, 26 November 2020 (UTC)

@DVdm: Hi, The link is relevant because of the following 3rd point in section wp:ELYES

"Sites that contain neutral and accurate material that is relevant to an encyclopedic understanding of the subject and cannot be integrated into the Wikipedia article due to copyright issues, amount of detail (such as professional athlete statistics, movie or television credits, interview transcripts, or online textbooks), or other reasons."

The site that I have linked to is an online textbook and it does contain neutral and accurate material that is relevant to an encyclopedic understanding of the subject of both Relative velocity and Velocity-addition formula. The content of the site cannot be added to the existing articles because of the amount of detail.

Request you to re-add the links or at least give tell me a what I should do I make my site as a "recognised authority". I would like to add many such links on various topics related to maths/physics and other subjects on other articles as well. Aruphore (talk) 11:30, 26 November 2020 (UTC)

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

The problem with your links, is that they appear on some personal web page that is not written by a recognised authority, so they do not qualify. Think of recognised authorites as people such as for instance Brian Greene, Roger Penrose, or John Baez. Some pages on their personal websites can indeed be used as external links. - DVdm (talk) 12:58, 26 November 2020 (UTC)

@DVdm: Hi, I believe the relevance/accuracy of the link should override the clause personal web page that is not written by a recognised authority. I am sure if you have it verified by experts you will find the content of the link very relevant to the articles Relative velocity and Velocity-addition formula as it greatly simplifies the understanding of these formulae. Requesting you once again to re-add the links based on relevance/accuracy.Aruphore (talk) 13:43, 26 November 2020 (UTC)

Anyone can (and does) write anything on any personal web page. Earth is flat, 0.999... is not 1, and they never landed on the moon, right? Your (and my) assurance that the content is correct, is entirely irrelevant. The problem is that it would put the burden to go and verify the content upon every single reader who visits the page. There is a very good reason why one of the fundamental policies of Wikipedia is wp:verifyability. Another fundamental policy is wp:consensus. The addition of your link violates both. It's not going to happen. Look at this as a first lesson on Wikipedia. There's more to learn, but take it one at the time... - DVdm (talk) 15:37, 26 November 2020 (UTC)

@DVdm: Allow me to correct you Sir. Firstly, This is not a personal website/webpage. StemAndMusic an online textbook just like Hyperphysics or Libretexts (not as popular as them as of yet but nevertheless well researched). Secondly, I am willing to give calculations that verify the formulae that are given in the link (which will eventually be the on the website). Could you please tell me how did you verify/reach to a consensus for following external links that are already present in the article Relative velocity

• Relative Motion at HyperPhysics
• A Java applet illustrating Relative Velocity, by Andrew Duffy
• Relatív mozgás (1)...(3) Relative motion of two train (1)...(3). Videos on the portal FizKapu. (in Hungarian)
• Sebességek összegzése Relative tranquility of trout in creek. Video on the portal FizKapu. (in Hungarian)

I am 100% sure that the link that I have provided is much more relevant to the learners of Relative Velocity related to Special Relativity than all the other currently present links combined. Kindly explain to me how the current links are relevant and my link is not.

Lastly Sir, I shall request you not to trivialize the highly scientifically relevant content that I have provided by comparing them with recreational topics like ″Earth is flat, 0.999... is not 1, and they never landed on the moon″. Pardon me (and correct me if I am wrong), but it somehow demonstrates your ignorance about the subject matter.Aruphore (talk) 18:40, 26 November 2020 (UTC)

I took those three silly examples to get across the point that anyone can produce web pages containing nonsense, and that our external links guidelines were put in place to prevent people from polluting our external links sections with websites that are not written by recognised authorities. The idea is (1) to keep them void of nonsense and spam, and (2) to release our readers from the burden of validating the content of these links. These readers include, (2.1) people like you and me, who can indeed verify the math and the physics, and (2.2) laypeople, who cannot do that, and who are restricted to at least somehow verifying the authority of the source. So again, whether the content on your website is correct and according to you highly scientifically relevant, is 100% irrelevant, as it is not authored by a recognised authority.

I'll tell you something else here (please follow the blue links and read the policies and guidelines): Wikipedia does not allow original research —- see wp:original research, another fundamental pollicy. If we create content, we cannot just include it on Wikipedia, unless it extensively appears in the established literature. The reason is twofold: (1) again verifiability, and (2) evidence that the content is indeed noteworthy to be taken on-board. That is why we need wp:secondary sources, rather than wp:primary sources.

About the presence of these other links, it is not because bad links exist in some articles, that more bad links should be added. On the contrary, if you encounter links that clearly satisfy wp:ELNO, then you should remove them, rather than adding more violations. Note however that some external links might have survived by de facto wp:consensus, (1) either silently by never getting removed (or even noticed), or (2) explicitly after talk page discussions. So before removing such old links, a new topic on the talk page might be appropriate, or a good explaining edit summary should be provided for the removing edit.

By the way, hyperphysics is bad — see the nonsense they write here. I warned them about this many times. They don't even bother to respond. What they say about relative velocity might be correct, but what they say about that paradox sucks. - DVdm (talk) 20:12, 26 November 2020 (UTC)

@DVdm: Sir, I believe you have something to do with the penmanship of these articles (Relative velocity and Velocity-addition formula ) and you do not want them to be significantly improved by any other person. I understand your insecurity. Thank you all the same, for your valuable time. Aruphore (talk) 20:50, 26 November 2020 (UTC)

@Aruphore: No problem. But, as you can easily verify in the edit histories of these articles, you are wrong about my penmanship of them, and about my motives and alleged insecurity. I am patiently trying to be helpful and, sort of, show you around here. I will put a welcome-menu on your talk page with more useful links. Enjoy! - DVdm (talk) 21:29, 26 November 2020 (UTC)

@Aruphore: As DVdm has pointed out, even sites that are generally considered reliable are not 100% so. One does not blindly follow supposed authorities. But the rules that DVdm has cited in wp:ELNO and wp:ELYES provide an important starting point for determining what external links may or may not be cited in Wikipedia. Ultimately, the interpretation of these rules and many other rules concerning wp:original research, the use of wp:secondary sources versus wp:primary sources and so forth is the result of consensus by the Wikipedia editors. I can emphasize with you, because when I was a newbie, I myself was burnt with a rules violation. But I have long since learned to appreciate why the rules make sense. Prokaryotic Caspase Homolog (talk) 03:08, 27 November 2020 (UTC)

Sir why you reverted my edit whats wrong in page equations

Sir why you reverted my edit whats wrong in page equations Prakharblue123 (talk) 18:26, 27 November 2020 (UTC)

All the edits was legit Prakharblue123 (talk) 18:28, 27 November 2020 (UTC)

@Prakharblue123: as I explained in my edit summary ([15]), please read the context as layed out in the sourced sentences immediately preceding your changes. So the edits were not legit, since in direct conflict with the preceding paragraph. Furthermore, as the text says, this is just an example, and there is no valid reason to just pick another example. - DVdm (talk) 18:37, 27 November 2020 (UTC)

But example is not correct according to the definition of algebraic equation Prakharblue123 (talk) 18:38, 27 November 2020 (UTC)

And it's not conflicting as well because 0 is an expression Prakharblue123 (talk) 18:39, 27 November 2020 (UTC)

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

The example is correct and consistent with the cited source in the preceding paragraph. And it is an example. - DVdm (talk) 18:43, 27 November 2020 (UTC)

It's getting confusing because according to Wikipedia only an algebraic equation is of form P=0 Prakharblue123 (talk) 18:50, 27 November 2020 (UTC)

Where P is polynomial Prakharblue123 (talk) 18:53, 27 November 2020 (UTC)

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

Wikipedia is not considered to be a reliable source for itself — see wp:CIRCULAR. Furthermore, the article Algebraic equation is not even properly sourced. - DVdm (talk) 18:55, 27 November 2020 (UTC)

Can I say that Ax^2 +Bx + c = y is equation but not algebraic equation ? Sir plzz reply Prakharblue123 (talk) 18:56, 27 November 2020 (UTC)

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

Ax^2 +Bx + c = y is also an algebraic equation — see the cited source in the preceding paragraph. - DVdm (talk) 18:59, 27 November 2020 (UTC)

Even I have asked my teacher about the same he said algebraic equation is always of form P=0 where P is polynomial Prakharblue123 (talk) 18:57, 27 November 2020 (UTC)

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

Alas, your teacher is not a reliable source for Wikipedia. - DVdm (talk) 19:01, 27 November 2020 (UTC)

Yes sir I agree but I read the source in Wikipedia and on that nothing is mentioned regarding " algebraic equation " Prakharblue123 (talk) 19:04, 27 November 2020 (UTC)

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

Repeating: Wikipedia is not considered to be a reliable source for itself — see wp:CIRCULAR.

This is the cited source of that preceding section: https://www.mathopenref.com/equation.html

- DVdm (talk) 19:14, 27 November 2020 (UTC)

First of all SORRY I don't know how to operate talk page and the page you sent me doesn't has single word regarding algebraic equation I know Wikipedia is not considered as reliable source though I want improvement to be made Prakharblue123 (talk) 19:18, 27 November 2020 (UTC)

Improvement is not needed here. - DVdm (talk) 19:22, 27 November 2020 (UTC)

Ok but I am unsatisfied because it is clearly wrong ! Prakharblue123 (talk) 19:24, 27 November 2020 (UTC)

Gravitational energy edits

Thanks for your message. The material I added is a pretty standard intro-level physics derivation and should be easy to find a source for. I noted in my edit summary that this step still needed to happen. I might suggest that a better procedure in these cases (and a very quick glance at your talk page suggests that this might have come up more than a couple times) might be (1) try to find a citation and add the reference, or (2) add a citation needed tag. Deleting without an attempt to find a source seems premature, at least to me. Am I off base here? DrPippy (talk) 18:48, 27 November 2020 (UTC)

@DrPippy: Hi there, yes, the material is pretty standard and correct. But it is wp:unsourced and way too complex to be an exception per wp:CALC. But the burden to get a citation is upon you — see wp:BURDEN. So yes, you are slightly off-base, in the Wikipedia sense, that is . - DVdm (talk) 18:52, 27 November 2020 (UTC)

I feel most physicists would put this under the umbrella of WP:CALC, although I could be wrong! Where would you consider to be the cutoff here? I'd suggest anything that appears in one of the standard intro physics texts is fair game. Another question is whether the article is improved by adding the content in question; if the answer is no, then the citation question becomes moot. DrPippy (talk) 19:02, 27 November 2020 (UTC)

Things like 5+5=10 are ok. Just plain elementary math. As soon as variables with physical meanings are involved, it isn't trivial math anymore.

If something appears in standard intro physics texts, then it should be very easy to mention the source with the fair game.

As for your other question, a source helps establishing whether some content is indeed noteworthy to be included in the first place. Something that is never mentioned in the literature surely has no place in Wikipedia — by design. - DVdm (talk) 19:10, 27 November 2020 (UTC)

I've done a little more looking around. This derivation is actually a homework problem in Giancoli (might be in the text in other books, but Giancoli is what I have handy), which makes me think that it's probably best if it doesn't show up on the page. (Don't want to make problems too easy for students, right?!) Thanks for the guidance; happy Friday! DrPippy (talk) 19:23, 27 November 2020 (UTC)

Good thinking - DVdm (talk) 20:24, 27 November 2020 (UTC)

Axes parallelism for a boost in arbitrary direction

Hi DVdm, I had a little interrogation about the section Lorentz_transformation#Vector_transformations. The illustration and its caption indicate that "The coordinate axes of each frame are still parallel and orthogonal" for a rotation-free boost along any arbitrary direction. I assume this is true in the limit of low velocities, but is it the case in general, as a boost generally don't preserve relative angles ? I guess that seen from one frame, the other one should appear distorted due to relativistic effects (except when the boost is along one specific axis), and thus orthogonality and parallelism should not be preserved. Am I misinterpreting ? Thanks. --Observateur01 (talk) 13:40, 28 November 2020 (UTC)

@Observateur01: I guess that with parallelism they just mean X || X', Y || Y' and Z || Z', and for orthogonality, X ⊥ Y ⊥ Z ⊥ T and X' ⊥ Y' ⊥ Z' ⊥ T', i.o.w. orthogonality within the frame. But I'm not sure, you better ask on the article talk page. Good luck there! - DVdm (talk) 16:21, 28 November 2020 (UTC)

Adding spoken language by someone alive on their page

Hello. I wanted to add on the page of someone who is still alive the list of the languages they speak. Which can of source should I provide? Thanks ~~~~ 78.193.210.180 (talk) 21:11, 7 December 2020 (UTC)78.193.210.180 (talk) 21:11, 7 December 2020 (UTC) — Preceding unsigned comment added by 129.194.217.204 (talk) 20:14, 7 December 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

A book or an article in a reliable journal or newspaper would be needed. As I said on your talk page, please see wp:reliable sources and wp:citing sources. - DVdm (talk) 20:27, 7 December 2020 (UTC)

Hello,

I understand and thanks for this link.

However, I do not know how possible this is. The person is a University professor, so they wrote plenty of articles in English. For the other langages, I don't know if there is any "proof" that exists. Does a set :::of Lecture Notes would work? 78.193.210.180 (talk) 21:11, 7 December 2020 (UTC)

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

No, having an article in English does not support the claim that someone "speaks German, English, French and Swiss German." Please stop adding this unsourced information, or you will end up blocked. If there is no proof, then Wikipiedia does not mention it — see wp:BURDEN. - DVdm (talk) 23:44, 7 December 2020 (UTC)

Hello,

Yesterday, I re-re-added this information using the reference (1) of the page, namely

https://www.academia-net.org/profil/prof-ruth-durrer/1163466

On this website, which is already cited by the article (Hence I assumed it to be considered as reliable), it is clearly indicates that the person speaks French, German and English.

Regarding Swiss-German, as it is mostly a spoken language/not an official langage, it is nearly impossible to find a source mentionning it, even though it is clear that someone born in Central Switzerland does speak German.

Let me also mention that on this Wiki page (https://es.wikipedia.org/wiki/Claudia_de_Rham) it is stated that this woman speaks 4 langages, but the link number (4) does not seem to work. This should be fixed as well then. — Preceding unsigned comment added by 78.193.210.180 (talk • contribs) 12:01, 8 December 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) and indent the messages as outlined in wp:THREAD and wp:INDENT — See Help:Using talk pages. Thanks.

Ok, that looks better. I have undone my revert, but left out the Swiss-German, as that is not sourced. - DVdm (talk) 12:19, 8 December 2020 (UTC)

Thanks! (~~~~) — Preceding unsigned comment added by 78.193.210.180 (talk • contribs) 12:24, 8 December 2020 (UTC)

why

	why god
	IT WAS NOT VANDALISM I WAS JUST ADDING A FAMOUS BROTHER DUO WOLVERINE AND VICTOR Shadowboxes6616 (talk) 16:54, 9 December 2020 (UTC)

See wp:reliable sources. Also note that Wikipedia generally does not appreciate joke edits. And please do not wp:SHOUT on talk pages. - DVdm (talk) 16:59, 9 December 2020 (UTC)

About the talk page

I want the article to mention the size of a photon. How should I proceed? Can I just a question? and later someone can judge whether this is relevant to add it to the article? Jackzhp (talk) 04:02, 24 November 2020 (UTC)

@Jackzhp: article talk pages are for discussions on how to improve the article, based on wp:reliable sources, so this comment was inappropriate. If you want to change the article by telling something about the subject, you need a reliable source, and then on the talk page you can propose to add something —that is supported by the source— to the article and see what other contributors say. But as I said before, don't ask questions on talk pages. If you have questions that you can't get answered with Google, then you can go to the wp:reference desk/science and ask there. Good luck. - DVdm (talk) 10:38, 24 November 2020 (UTC)

I think the size of a photon should be mentioned in the article. but I don't whether people can agree with me. so I asked a question, if people agree this is important, then related info will be add to the article. If I edit the article directly, I am afraid some people like you would delete it too. so I think I better to raise the question about its importance, then maybe some other experts can add it to the article. Jackzhp (talk) 13:29, 10 December 2020 (UTC)

I am not asking a question already mentioned in the article. but to say the article is missing something. Can you not to waste too much time on revert other people's editing on talk page? Jackzhp (talk) 13:32, 10 December 2020 (UTC)

Replied ([16]) at Talk:Photon#the size of a photon. - DVdm (talk) 15:47, 10 December 2020 (UTC)

New Page Patrol December Newsletter

Hello DVdm,

Year in review

It has been a productive year for New Page Patrol as we've roughly cut the size of the New Page Patrol queue in half this year. We have been fortunate to have a lot of great work done by Rosguill who was the reviewer of the most pages and redirects this past year. Thanks and credit go to JTtheOG and Onel5969 who join Rosguill in repeating in the top 10 from last year. Thanks to John B123, Hughesdarren, and Mccapra who all got the NPR permission this year and joined the top 10. Also new to the top ten is DannyS712 bot III, programmed by DannyS712 which has helped to dramatically reduce the number of redirects that have needed human patrolling by patrolling certain types of redirects (e.g. for differences in accents) and by also patrolling editors who are on on the redirect whitelist.

Rank	Username	Num reviews	Log
1	DannyS712 bot III (talk)	67,552	Patrol Page Curation
2	Rosguill (talk)	63,821	Patrol Page Curation
3	John B123 (talk)	21,697	Patrol Page Curation
4	Onel5969 (talk)	19,879	Patrol Page Curation
5	JTtheOG (talk)	12,901	Patrol Page Curation
6	Mcampany (talk)	9,103	Patrol Page Curation
7	DragonflySixtyseven (talk)	6,401	Patrol Page Curation
8	Mccapra (talk)	4,918	Patrol Page Curation
9	Hughesdarren (talk)	4,520	Patrol Page Curation
10	Utopes (talk)	3,958	Patrol Page Curation

Reviewer of the Year

John B123 has been named reviewer of the year for 2020. John has held the permission for just over 6 months and in that time has helped cut into the queue by reviewing more than 18,000 articles. His talk page shows his efforts to communicate with users, upholding NPP's goal of nurturing new users and quality over quantity.

NPP Technical Achievement Award

As a special recognition and thank you DannyS712 has been awarded the first NPP Technical Achievement Award. His work programming the bot has helped us patrol redirects tremendously - more than 60,000 redirects this past year. This has been a large contribution to New Page Patrol and definitely is worthy of recognition.

Six Month Queue Data: Today – 2262 Low – 2232 High – 10271

To opt-out of future mailings, please remove yourself here

18:17, 10 December 2020 (UTC)

Richard Dawkins

Hey,

You revoked my removal of 'outspoken' from Richard Dawkins's Wikipedia page. I removed this as this is what the religious call him as if it is a weakness of his. He mentions in his book 'The God Delusion' and also in the below article, that he is actually an agnostic and he doesn't like the terms 'outspoken' or 'militant':

https://www.theweek.co.uk/religion/religion/45552/outspoken-atheist-dawkins-admits-he-agnostic

Can you revoke the revoke please?

Cheers — Preceding unsigned comment added by 80.192.129.229 (talk) 08:44, 15 December 2020 (UTC)

Please sign all your talk page messages with four tildes (~~~~) — See Help:Using talk pages. Thanks.

Was already done by user GorgeCustersSabre. Please note that an edit summary would have saved you the trouble coming here to explain . - DVdm (talk) 10:19, 15 December 2020 (UTC)

A barnstar for you!

	The Editor's Barnstar
	hey hru i think u deserve this for helping alot of peeps Sebey2007 (talk). 18:51, 16 December 2020 (UTC)

A barnstar for you!

	The Writer's Barnstar
	cool u definitely deserve this awesome job Sebey2007 (talk). 18:59, 16 December 2020 (UTC)

Don Page arXiv preprint (re: Observable Universe edits)

Hi, I'm just a bystander, but I'm curious about why you reverted the mention of this article: https://arxiv.org/abs/hep-th/0610199 I don't know what the policies are on WP for citing arXiv directly, but it seems to be common in physics articles (and it's hard to imagine how you could write a good article otherwise). I can imagine a couple reasons for rejecting a particular citation but I don't really know what the rules are. (Page himself is pretty highly regarded but writes weird stuff sometimes; this article seems fine to me but I don't feel strongly about it. I'm more interested in the procedural question.) Patallurgist (talk) 22:08, 20 December 2020 (UTC)

@Patallurgist: Assuming you are referring to this, see WP:Reliable sources/Perennial sources and search for arXiv: "arXiv is a self-published source, and is generally unreliable..." So we can say that the de-facto standard prodedure more or less goes like, when in doubt, remove. As indeed the author is known to write weird stuff, this will probably do no harm. In the cases where harm is done, we have the article talk pages to put things straight . Hope this helps. Cheers - DVdm (talk) 00:38, 21 December 2020 (UTC)

Thanks for pointing me in the right direction. I do want to note that the list entry says arXiv is "generally unreliable with the exception of papers authored by established subject-matter experts", and more importantly, the Page article in question has in fact been published in a peer-reviewed journal. AFAICT the list entry suggests changing the reference link to point to the journal (easy to Google, DOI's on the arxiv page) rather than removing the content in this sort of situation. (To clarify: "weird" meant "weird choices of topic", not unreliable conclusions. Page's papers are much more likely to be *correct* than the average peer-reviewed cosmology paper. Sorry if that was misleading.) I certainly hope you didn't remove that chunk of content based on the URL alone... Patallurgist (talk) 05:24, 21 December 2020 (UTC)

Indeed no, it was based on the combination of a number of flags, as I explained on the talk page Talk:Observable universe. - DVdm (talk) 11:18, 21 December 2020 (UTC)

Acquisition of Wondery

Recently, Amazon has acquired Wondery. I would be glad if you would kindly update the owner section of it. I can edit but I do not know how to cite URL.

Regards. Ayush6568 (talk) 03:41, 31 December 2020 (UTC)

Here is the cite URL-

https://www.nytimes.com/2020/12/30/business/dealbook/wondery-amazon-podcasts.html Ayush6568 (talk) 03:52, 31 December 2020 (UTC)

@Ayush6568: not being familiar with the subject, I suggest you ask this at the talk page of the article Talk:Wondery. Someone who has the article on their watchlist will then do what it takes. Good luck and a happier 2021! - DVdm (talk) 11:15, 31 December 2020 (UTC)

Thank you! Wish you a happy 2021!

🍾 Ayush6568 (talk) 12:44, 31 December 2020 (UTC)