Talk:Black hole/Archive 16

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Absence of central singularity according to new scientific articles

I would like to propose to add this new sub-section, because of valid primary and secondary sources :

Absence of central singularity according to other theories

(last updated 07:12, 18 January 2019, accordingly to remarks done at the bottom)

On December 10, 2018, Abhay Ashtekar, Javier Olmedo, and Parampreet Singh published a scientific paper in the field of the theory of loop quantum gravity demonstrating the absence of central singularity within the black hole, without geometrically specifying the state of matter at this point.. The absence of central singularity within the black hole was debated between some astrophysicists since a long time in the frame of general relativity , including in the media . This debate is not closed since the last 2016 "pro" singularity paper is not discussing the last 2015 "con" singularity paper . --80.215.224.16 (talk) 16:42, 12 January 2019 (UTC) for the first iteration

References

Some of the papers cited do not seem to have been published in peer-reviewed form. Also, the proposer should clarify what relationship he may have with any of these manuscripts. WolfmanSF (talk) 17:43, 12 January 2019 (UTC)

Correct, some of the papers are pre-print articles on researchgate or arxiv. They add others technical details for the ones interested in these, and they demonstrate that the previously published works created interest in the scientific community. They should be considered as secondary sources.

The proposer is not one the authors whose papers are listed here, nor a co-worker nor a relative, nor involved in commercial activities with one of these authors.

— Preceding unsigned comment added by 80.214.75.88 (talk)

This work is, at best, too new and speculative to be included, per WP:UNDUE. XOR'easter (talk) 19:52, 15 January 2019 (UTC)

WP:UNDUE reads "Once it has been presented and discussed in reliable sources, it may be appropriately included." More, UNDUE refers to the weight in the article (note that I propose only 2 short sentences), not to a new idea. Because the sources are valid and verifiable, it is not a speculative opinion at all.--80.215.97.25 (talk) 22:13, 15 January 2019 (UTC)

Your sources are not all reliable, and the reliable ones among them are not all about the topic that your text claims they are. Your proposed addition violates WP:UNDUE by over-emphasizing the most recent iteration of a concept (that the central singularity might vanish in a fully quantum treatment). XOR'easter (talk) 15:57, 16 January 2019 (UTC)

Please list the sources which are not reliable for you in the context of these sentences. Let's start with this. --145.242.20.219 (talk) 17:12, 16 January 2019 (UTC)

1 is not reliable (Wikipedia is not a reliable source for itself). 2 is a primary source on work that is still too new to have been fully evaluated. 3 is Carlo Rovelli's commentary on 2; it's fine. 4 is borderline (online publication with no obvious red flags but no indication of how much editorial control it exercises, either). None of 2, 3 or 4 refer to the Janus model, which you are clearly trying to promote. 5 through 8 are complaints by a niche of researchers on the fringes of GR that have largely been ignored, justifiably, and that have no real connection to the topic of sources 2–4. Reference 9, if anything, presents a happily mainstream position and argues in the opposite direction from references 5–8. Reference 10 is only on the arXiv, and so is not reliable. Reference 11 is on ResearchGate and thus counts for nothing. Items 11 and 12 are an interview with Jean-Pierre Petit, whom you are trying to promote, and for present purposes, these sources count for nothing. Reference 14 is another PDF on Petit's ResearchGate page, and so it is not a reliable source. In summary, the only reliable sources actually germane to the topic of "the absence of [a] central singularity" are sources 2 and 3. XOR'easter (talk) 17:46, 16 January 2019 (UTC)

The whole proposal comes across as a ploy to generate views of some of the "secondary sources". WolfmanSF (talk) 18:24, 16 January 2019 (UTC)

@XOR'easter : I have updated the proposed text and sources according to your last message. Please let me know of any details. Note there are 2 sentences, each with their sources. Accordingly, sources for sentence 2 do not deal with sentence 1.--145.242.20.220 (talk) 09:59, 17 January 2019 (UTC)

You are still including unreliable sources and over-emphasizing the most recent conjecture about an old topic (an old topic that, indeed, the article already discusses to an adequate extent). In addition, your text is historically misleading, since the question of the central singularity — whether it is of a different nature than the coordinate singularity at the Schwarzschild radius, if it is a generic feature of gravitational collapse, what new physics might come into play in that regime, etc. — is much older than 1979. Nor is including in the media a helpful statement: it's a given that some amount of pop-science coverage is likely to exist for a subject like black holes. Unless the media involvement itself is part of the story in a meaningful way (e.g., when scientists rush to give a press conference before peer review), it's not worth mentioning here.

As a matter of Talk-page etiquette, editing your own comments after other people have replied to them makes a conversation difficult to read and is frowned upon. XOR'easter (talk) 16:51, 17 January 2019 (UTC)

@XOR'easter : I have reformulated the proposed text according to your last message. The sources are kept, they are all valid (no arxiv-only, no researchgate only). The media sources (secondary) are useful to demonstrate this debate is of a relative public importance and not only between unknown specialists, then it is worth to be mentioned on WP. Please let me know of any details.

About the Talk-page etiquette, please note I only edit the proposed sub-section (as you can do yourself) like we might do directly in the article if it were open to contributions, in order to reach quicker the consensus and to be much much easier to read this thread. Then the Talk-page etiquette is respected, at least in its spirit.--80.78.5.104 (talk) 07:17, 18 January 2019 (UTC)

You are compounding the problem by continuing to edit text to which other people have already replied, thereby making replies to your proposal more difficult to understand. In no way does this respect the "spirit" of Talk-page etiquette. Your "media sources" do not demonstrate the "relative public importance" of this topic; two out of three are Petit promoting himself, nothing more, and the third is an unsigned blurb that might as well be a regurgitated press release. Your most recent modification furthers the violation of policy by using Wikipedia to advertise a paper that has been all but ignored by scientists. XOR'easter (talk) 17:59, 18 January 2019 (UTC)

Please do not try to divert attention with far-side topic like vague personal interpretation of etiquette. I just want to focus on the proposed section. Please note I didn't modify it this time (check history if you prefer).

I proposed only 2 media sources : refs 10 and 11. Where do you see a third one?? It cannot be Ref13, which is a published paper in a peer-reviewed scientific journal... so where is this third one?

Refs 10 and 11 are interviews of Petit. Do you mean any interview is a promotion of the interviewed ? Nevertheless, this are valid secondary sources. I guess you will not say Petit has asked Putin to order Sputniknews to interview him, or will you?

Do you really mean that because Ref13 has not been cited inside Ref12 or elsewhere, Ref13 should not be considered as a valid primary source and then does not deserve to be mentioned here? If yes, where is that rule written please? (answer: nowhere)

Oh, a last thing: I just read in your User page you are feeling depressed these days because "Wikipedia has been a depressing place lately, or perhaps I've just been spending too much time in depressing parts of it." I've got a miracle medecine for you : because you seems to master at least a thing or two in mathematics, please read carefully Ref13 and try to find an error inside this (superb) mathematical demonstration. It will obviously bring you a lot of energy because you know nobody has ever found an error inside. You will be the first I'm sure! Please do it :)

--88.174.103.32 (talk) 21:08, 18 January 2019 (UTC)

Please do not try to divert attention with far-side topic like vague personal interpretation of etiquette. It's not vague or personal; it's down in black and white.

I proposed only 2 media sources : refs 10 and 11. Reference 3 is a news source (the one I described as "an unsigned blurb that might as well be a regurgitated press release").

Refs 10 and 11 are interviews of Petit. Do you mean any interview is a promotion of the interviewed ? Many of them are. These certainly are. In some cases, interviews can be indicators that the person being interviewed is notable, because they indicate the wider world paying attention to that person, but that is irrelevant here. We are evaluating the notability of (nominally) scientific ideas, and we do that by seeing if they have been influential within the scientific community.

Do you really mean that because Ref13 has not been cited inside Ref12 or elsewhere, Ref13 should not be considered as a valid primary source and then does not deserve to be mentioned here? Yes. That is how we do things here. Wikipedia reports mainstream scientific consensus; it does not attempt to change it. Wikipedia is not the place to promote research that has not already demonstrated itself. See WP:NOR, WP:FRINGE and WP:UNDUE. XOR'easter (talk) 21:29, 18 January 2019 (UTC)

I agree that this thing is based on bad sources (wp:FRINGE and WP:UNDUE), and the valid sources are abused to create a new synthesis ("This debate is not closed since...") and thus amount to wp:original research — see wp:SYNTH. - DVdm (talk) 22:08, 18 January 2019 (UTC)

Okay, let's go back to the beginning. First, you should clarify any possible conflict of interest in these research area.

1) Are these sentences correct ? Any bad source ?

"On December 10, 2018, Abhay Ashtekar, Javier Olmedo, and Parampreet Singh published a scientific paper in the field of the theory of loop quantum gravity demonstrating the absence of central singularity within the black hole, without geometrically specifying the state of matter at this point . This publication has attracted public attention in many countries, making it even more worthy to be mentioned on WP ."

2) Please explain why mentioning the above sentences is a violation of FRINGE or UNDUE or any other WP rule. Keep in mind that modern Flat Earthers section is accepted https://en.wikipedia.org/wiki/Flat_Earth#Modern_Flat-Earthers

References

--88.174.103.32 (talk) 08:32, 19 January 2019 (UTC)

I forgot to mention wp:CONSENSUS here above. To establish that, Wikipedia has wp:Dispute resolution. - DVdm (talk) 10:08, 19 January 2019 (UTC)

Let's use, as we tried since the beginning of this proposition, to focus on content https://en.wikipedia.org/wiki/Wikipedia:Dispute_resolution#Focus_on_content . Can anybody answer questions 1) and 2) above 08:32, 19 January 2019? --80.215.6.178 (talk) 10:36, 19 January 2019 (UTC)

You continue to over-emphasize an idea that has not yet been vetted by the scientific community (formally published only last month), and you are bulking up the citations with press releases and other low-quality material. On a more minor note, your phrasing "making it even more worthy to be mentioned on WP" violates the Manual of Style. And as for your second question, WP:FRINGE already explains quite clearly how Flat Eartherism and other conspiracy subcultures, hoaxes and pseudosciences can be notable in their own right. Unless you are claiming that the work of Ashtekar et al. is plainly erroneous yet has a cult following that makes it noteworthy, the comparison to Flat Earthers is completely beside the point. XOR'easter (talk) 18:44, 19 January 2019 (UTC)

This is a pretty clear example of someone trying to game the system to provide exposure for a particular author. As such, I don't see why dispute resolution is needed. WolfmanSF (talk) 20:03, 19 January 2019 (UTC)

If I understand your answer, you didn't give any argument based on rule to reject the sentences (with the exception of your more minor note). There is NO existing rule against mentioning such facts in WP, whereas the publication was made in december. There is NO rule saying "the mention of a scientific result must wait to be vetted by the scientific community". BTW, the "scientific community" has spoken once when the paper was published and twice when it was commented by Rovelli. I know the scientific community at least as much as you. In this case I ask you, or any user reading this, to add now these sentences into the article (the article is protected from editions by IP). Whatever you think about me or about this scientific result, this is the rule of WP. --80.215.6.178 (talk) 23:10, 19 January 2019 (UTC)

No, it isn't. The mere existence of a paper does not make it necessary, obligatory, beneficial or reasonable to include here. Plenty of papers are published and then forgotten. Nor is the existence of one (1) brief commentary enough to tip the scales. That holds for any page on Wikipedia, and for an article like this one, an overview of a major topic in physics and astronomy, we must naturally set the bar higher. You're demanding an exemption from the basic policy of notability. And, far from there being NO rule saying "the mention of a scientific result must wait to be vetted by the scientific community", that exact thing was the motivation for the No Original Research policy in the first place. Of course, that original motivation has been elaborated and refined by years of hard-earned experience, recognizing the hazards of recentism and the like. XOR'easter (talk) 04:28, 20 January 2019 (UTC)

Please note that :

a) WP:RECENTISM is not a WP rule, it's only a guideline not endorsed by WP EN.

b) WP:RECENTISM apply to events, and daily news. This is not relevant for our topic. We are dealing with serious and valid primary and secondary sources, according to WP rules.

c) there is strictly zero Original Research in the proposed sentences. Read again the definition if this rule.

You say the proposed sources are not enough. Please answer these questions :

1) where is written that the present article should be considered with different rules than others WP articles ?

2) to clarify Notability, give us a precise list of the minimum mandatory criteria (qualitatively and quantitatively) to add the proposed sentences in the article, according to yourself (for instance: the authors must received Nobel Price, one of them has to be named Time's magazine Man of the Year).

3) map each criteria with a WP rule (not a guideline)

If you fail to provide 3) in a few days, then this would mean your approach is arbitrary. Such approach, a.k.a censorship, has no place in WP. --80.215.195.0 (talk) 09:05, 20 January 2019 (UTC)

The ultimate policy that plays here, is wp:CONSENSUS, which, in practice, trumps all other policies and guidelines on Wikipedia. It seems that there is no consensus to take your changes on board, and I think that you are wasting your (and other contrutors') time on this talk page. Beyond focus on content, your next possibilities are outlined at wp:DR. - DVdm (talk) 11:22, 20 January 2019 (UTC)

Thank you DVdm for your assistance, but I would prefer to wait for XOR'easter to provide 3) as required. If this fails, I would then be interested in knowing why seeking a possibility in wp:DR is mandatory when discussing with someone who, if this happens, would have proven to prefer censorship. --80.215.195.0 (talk) 12:55, 20 January 2019 (UTC)

Maintaining the scholarly standards of this encyclopedia is not "censorship". Since it is quite clear that nothing I provide, whether exact quotes from policies or discussions of the general themes and values that our guidelines reflect, will change your mind, I see no reason to carry this further. XOR'easter (talk) 17:45, 20 January 2019 (UTC)

Scholarly standards?? Who do you want to confuse XOR'easter? You are far far away from them. You failed to answer my simple questions. Test failed => you rely on arbitrary feeling and/or conflict of interests => censorship. --80.215.102.103 (talk) 19:56, 20 January 2019 (UTC)

I have no conflict of interest here, financial, intellectual or otherwise. You are escalating your accusations without evidence. Bad look. XOR'easter (talk) 20:44, 20 January 2019 (UTC)

If there is no conflict of interest here, and I can believe it, then the first conclusion is still valid : Test failed => you rely on arbitrary feeling, even if you do not catch it. — Preceding unsigned comment added by 145.242.20.218 (talk • contribs) 11:53, 21 January 2019 (UTC)

Actually, I generally like offbeat speculations in physics, and I appreciate well-thought-out minority opinions — there's always the chance that the orthodox are missing something because they lacked imagination at a critical point. And I usually like the writing of Carlo Rovelli (author of reference 3), which I find mostly clear and thought-provoking even when I end up disagreeing with his opinions. So, on sentimental grounds, I would be inclined to ditch policies and guidelines and write about any conjecture that had survived the slightest bit of critical scrutiny. But that's not what this encyclopedia is about, and thus I work to apply those policies and guidelines, even when it's not any fun. XOR'easter (talk) 17:57, 21 January 2019 (UTC)

Whatever you try to explain about your motives, you still rely on a feeling "about any conjecture that had survived the slightest bit of critical scrutiny", without precisely defining what is the "slightest bit of critical scrutiny" (cf questions in my test you d'ont even start to answer). You failed the test, and you just deny it. I can understand that, and believe me I just don't need to convince you. Ultimately, you can't stop the truth out. Nobody can. --145.242.20.217 (talk) 09:31, 23 January 2019 (UTC)

Semi-protected edit request on 31 March 2019

I want to give the reference to black holes so I want to edit it .Thanks for later. Shivangsingh478 (talk) 16:16, 31 March 2019 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. – Þjarkur (talk) 16:19, 31 March 2019 (UTC)

Also please note that you cannot add links to your own blog. It is not a reliable source. – Þjarkur (talk) 16:21, 31 March 2019 (UTC)

Where will the new fru fru pic go

hi, heard that there will be a real-life pic of a black hole released soon. will this pic go at the top of the page or will it be buried somewhere in the article? seems like it would be a very important and a coolio thing to have at the top. blurry pics of Pluto were used for a long time on its article so quality doesn't have to be Super HD or anything right? the situations aren't perfectly analogous of course, but you know what i mean perhaps. From, 138.9.181.35 (talk) 03:03, 9 April 2019 (UTC)

Since the greatly anticipated imagery will be of Sagittarius A* and its immediate surroundings, I suspect it should properly go in that article, as opposed to this one (which deals largely with the physical properties of black holes in general). DWIII (talk) 22:15, 9 April 2019 (UTC)

hmmm, i see what you are saying. but also here on the dwarf planet page there are pics of real-life dwarf planets at the top, not just a cool math equation with "part of a series on cosmo objects". although, to similar effect of what you are saying, on the atom page there is a artificial image of an atom, not a real-life pic of an atom taken with new fru fru tech. what a discussion! From, 138.9.162.60 (talk) 04:00, 10 April 2019 (UTC)

The new image is actually of Messier 87 and it has been published by the CBC in Canada. Here's the URL: https://www.cbc.ca/news/technology/event-horizon-telescope-black-hole-photographed-1.5081243. I'm not an astrophysicist so I don't feel comfrotable adding or summarizing this news in this article. Mcbrarian (talk) 13:44, 10 April 2019 (UTC)

Semi-protected edit request on 10 April 2019

Please update the current picture of a black hole to the new picture provided from the Event Horizon Telescope Collaboration, via National Science Foundation. CS0607 (talk) 14:05, 10 April 2019 (UTC)

Will be done when someone uploads it. – Þjarkur (talk) 14:59, 10 April 2019 (UTC)

Estimates place it at billions of times the suns mass

Says the note under the photo at the top. Perhaps adding the word 'several' in there would strike a balance between the first part of this sentence being overly vague, and causing the sentence to sound repetivive. LastDodo (talk) 15:53, 10 April 2019 (UTC)

I believe that has been addressed, although in a different way. WolfmanSF (talk) 19:10, 10 April 2019 (UTC)

First Image of Black Hole

An article with the name of "First Image of Black Hole" might be created that describe the information regarding the back end process and activities of this achievement. Sumit Singh ^T 11:29, 11 April 2019 (UTC)

Model image for M87

It would be good to see if we can secure permissions to reproduce the model image of M87 from this paper: [1] (Akiyama et al, First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring, Astrophysical Journal Letters, 875(1), 10 April 2019), to give an idea what the system might look like without the blurring that is an inevitable consequence of the finite synthetic aperture of the radio-telescope network.

From the Get permission to re-use this article link at the top, it would seem that the AAS will permit reuse if permission is granted by one of the authors, on terms that look to be broadly similiar to CC-BY.

Would one of the regular editors on this article be prepared to take this forward? Jheald (talk) 13:47, 11 April 2019 (UTC)

Yes yes yes someone please do that. Artoria2e5 🌉 02:46, 12 April 2019 (UTC)

Cropped image or the original?

Black hole - Messier 87 (cropped)

Black hole - Messier 87

So should we use the full size image or the cropped version as the main picture for the article? --Roopeank (talk) 14:39, 11 April 2019 (UTC)

Leaning to the cropped one. If the rest of the image is all black, chances are they probably only reconstructed the part around the black hole and padded the image for a nice aspect ratio. Artoria2e5 🌉 02:49, 12 April 2019 (UTC)

Semi-protected edit request on 15 April 2019

I suggest adding the following section:

Similar idea in Buddhism

Gautama Buddha (c. 563/480 – c. 483/400 BCE) spoke about a similar concept in Andhakara (Darkness) Sutta in the Saṃyutta Nikāya section of the Tripitaka:

The original text which was in Pali was translated by Ṭhānissaro Bhikkhu and Bhikkhu Bodhi as follows:

"There is, monks, an inter-cosmic void, an unrestrained darkness, a pitch-black darkness, where even the light of the sun & moon — so mighty, so powerful — doesn't reach." - Ṭhānissaro Bhikkhu

“Bhikkhus, there are world interstices, vacant and abysmal regions of blinding darkness and gloom, where the light of the sun and moon, so powerful and mighty, does not reach.” - Bhikkhu Bodhi

Sources:

• https://www.accesstoinsight.org/tipitaka/sn/sn56/sn56.046.than.html
• https://suttacentral.net/sn56.46/en/bodhi Chanaka.palli (talk) 17:01, 15 April 2019 (UTC)

 Not done Neither of the sources provided give contemporary analysis linking these texts with the modern scientific understanding of a black hole. While secondary sourcing making this connection is a clear prerequisite to this information being included in the article, the viewpoint's inclusion would also be subject to editorial discretion and should be discussed on the talk page to establish consensus before another edit request is made. VQuakr (talk) 17:27, 15 April 2019 (UTC)

Request for removing of a "black hole image" of an Event Horizon Telescope from Wiki page

Not done

This image must not be published by Wikipedia while the EHT's team don't show us exact algorithms they used for reconstruction of it. An EHT's image is biased and probably due to aberration error. Simulation of gravitation lens inside accretion disk https://qph.fs.quoracdn.net/main-qimg-9f25b9f6b3cc85121faf316a3cd38e1a Spherical aberration in an optical telescope https://qph.fs.quoracdn.net/main-qimg-1bdbb362446b48d94593ba1d8ff24c20 Above frames are from this video, without almost nothing image processing except color balance. https://www.youtube.com/watch?v=MFmFpuST67M Why Wikipedia disseminates information that has not been confirmed by external scientists, but only from an Event Horizon Team,which are an interested party in disguise their error? https://www.quora.com/Why-cant-the-image-they-present-to-you-as-an-image-of-a-black-hole-be-a-black-hole-image-at-all-and-how-should-an-image-of-a-black-hole-look-for-us-as-external-observers 84.238.150.11 (talk) 09:33, 1 May 2019 (UTC)

This message has been spammed across multiple talk pages and is not reasonable on any of them. XOR'easter (talk) 15:21, 1 May 2019 (UTC)

Axe to grind. See also same location IP 87.126.175.254 (talk · contribs · deleted contribs · logs · filter log · block user · block log) aka RustyBrain (talk · contribs · deleted contribs · logs · filter log · block user · block log), now indef blocked for their conduct at Gravitational lens and Talk:Gravitational lens. - DVdm (talk) 08:26, 6 May 2019 (UTC)

So, you have reverted my 6 edits.

@Deacon Vorbis Okay, let's check them out, one by one, starting with this edit? What was wrong? Have you ever heard about misplaced modifiers? Vikom ^talk 01:57, 4 May 2019 (UTC)

That's not a misplaced modifier. –Deacon Vorbis (carbon • videos) 04:16, 4 May 2019 (UTC)

@Deacon Vorbis: So, according to you, the following sentences mean the same, right?

• I ate only vegetables.
• I only ate vegetables.

Vikom ^talk 15:54, 4 May 2019 (UTC)

If you have a point to make, then make it; I'm not going to play 20 questions. –Deacon Vorbis (carbon • videos) 16:04, 4 May 2019 (UTC)

Vikom, no, what he's saying is that "only correct near" and "correct only near" mean the same.

The vegetable example is a bad one. You can grow or chop or eat or do eighty gazillion things to vegetables. Correct has a single alternative: incorrect. Near has a single alternative: not near. So you don't get the same potential confusion in idiomatic English. --valereee (talk) 16:07, 4 May 2019 (UTC)

Dear Valereee, I understand the message that you are trying to convey :-) The problem is that the existing wording is worse than ambiguous, it is misleading illogical. Just because we can easily guess the intended meaning of "only correct near" does not make it a good idea. In this case the context helps but simultaneously forms a bad habit, which can lead to ambiguity or something worse in a different context. Let me give you an analogy. Putting fingers into an electric meat grinder that does not work is theoretically safe, but I would not recommend it to anyone. My version ("correct only near") is logical and covered by a reliable source. Excuse the rhetorical question, but why do not you show me your source?

Language changes constantly and is influenced by our choices of words and phrases. So, instead of accepting everything what we hear, let's make good choices to make English better. Otherwise we will have more and more incorrect constructions like "oftentimes", "the reason is because", or "didn't used to be". English, like any other natural language, is inconsistent and illogical, which applies also to grammar *. But whenever we have a choice, we should choose the best option. Not only for us but also for future generations because Wikipedia is frequently used by children and young people.

* I am well aware that the more common version is "which also applies to grammar", but this is a classic example of a misplaced modifier.

Vikom ^talk 04:51, 5 May 2019 (UTC)

@Deacon Vorbis: What was wrong with this edit? I have provided a very clear explanation: "A very misleading title: It was beautiful and impressive but only a simulation". Vikom ^talk 23:29, 5 May 2019 (UTC)

That's probably fine to put back if you really want to. It's not really all that misleading, as I can't imagine anyone reasonably thinking this is anything but some sort of simulation. On a side note, if you expect me to respond to messages like this, it would probably be best not to call me names. –Deacon Vorbis (carbon • videos) 01:15, 6 May 2019 (UTC)

@Deacon Vorbis: "I can't imagine anyone reasonably thinking this is anything but some sort of simulation." OMG, What? Are you serious?

Everything seemed to be fine until your careless disrespectful massive revert. Now, I am broken and see that you can revert all my edits ever made, especially that many of them were corrections of misplaced modifiers, and I am in fear. Should I consult every future edit with you? But it implies that I should wait for your permission before each edit, otherwise all my efforts might be in vain. Of course, theoretically, I can make a single edit and wait for your possible revert, but it does not change much. And what if you are absent for a week or more? I will always be unsure. Of course no editor can be absolutely sure but normally my edits are reverted sporadically. You felt insulted by my word "self-important", but, after what you have done, it is rather a pretty tactful euphemism, especially that I still feel as if you were my boss.

As for black holes, I am not an astronomer or physicist, but physics was my passion in high school. I have even been awarded in a nationwide physics competition in my country. My another passion is philosophy, which seems to be helpful in editing anything. Judging by your page you are a programmer. I am a programmer too, and I have written hundreds of thousands of lines of code in my career. I do not consider myself a brilliant polymath, but I have done a lot in a variety of fields, mostly as an autodidact. But you treat me as if I were a child or someone who knows nothing about anything.

To sum up, maybe I will stop editing. So far, I have not made any edit for 4 days, which for me is no small feat. Vikom ^talk 03:33, 8 May 2019 (UTC)

Watch out for that door. VQuakr (talk) 04:11, 8 May 2019 (UTC)

@VQuakr: I followed your link and found this: "Occasionally, some long-time users come to believe they are more important than other editors, and act in ways that seek to regularly receive validation of that belief. [...]" Let's go into details:

• "[...] Occasionally, some long-time users [...] "

Although I registered here 10 years ago, my contribution is very small (about 400 edits). And most of them were made during the last 15 months.

• "[...] come to believe they are more important than other editors [...] "

Is it me who is self-important?

• "[...] and act in ways that seek to regularly receive validation of that belief. [...] "

"regularly"? When was the first time? I can only guess that my first time is taking place now. Yes, here and now ;-) So, rhetorically speaking, those 7 consecutive reverts have just been provoked by me, right?

• "[...] Validation is obtained by delivering and obtaining compliance with ultimatums [...] "

Sorry but I gave no ultimatum. I was only contemplating the reason of my (modest) activity here. But now, looking back, I see that the sentence "maybe I will stop editing" was unnecessary because it may have been perceived as emotional blackmail. Maybe my activity here is no problem for anybody because reverting is a very easy and fast procedure. However I did want to know the reaction of my opponent.

• "[...] The writer hopes that this fit of pique will attract a flood of "please don't go" messages [...] "

Even if I needed such an empty ritual I would not count on it because I am a realist. By the way, the only message I have received so far comes from you. And it is not a "please don't go" message. Just the opposite ;-)

Vikom ^talk 03:03, 9 May 2019 (UTC)

"no particles" can escape? oh really.

No KNOWN particles. Someone please fix. 2600:6C54:4400:C76:DC84:AA83:5D2E:3C62 (talk) 13:41, 27 June 2019 (UTC)

We'll fix it as soon as we know unknown particles. Promised. - DVdm (talk) 13:50, 27 June 2019 (UTC)

@DVdm: I heard Johann Gambolputty of Ulm is in line for a Nobel prize his ground-breaking hypothesis that unknown particles may be responsible for doing things we never saw. Headbomb {t · c · p · b} 19:17, 27 June 2019 (UTC)

Changing the images in the intro to the "Observational evidence" section to have the same height.

@Iryna_Harpy What do you mean "The screen resolution is not going to be the same on different devices"? Are you saying the image won't display correctly on devices with smaller screens? Then shouldn't all the images be resized? Clearly if the image next to the one I was editing is fine at its current size, then the other image should also be fine at that size? Auguel (talk) 15:52, 29 June 2019 (UTC)

The {{Multiple image}} template has a nice feature where you can use the total_width= parameter to set the total width, and the template will automatically set each image to the right height, keeping all aspect ratios intact. I've gone ahead and updated the template in the article with a total width approximately equal to what was already being used, rather than tweaking each width manually. –Deacon Vorbis (carbon • videos) 16:30, 29 June 2019 (UTC)

@Auguel: Thanks to Deacon Vorbis for the tweak as I notice that I was slack and didn't actually substitute with a different scaling format/style. What I was referring to is that absolute values aren't the ideal way to set up a web site. Just as an example, 245px is big enough to take up the width of an iphone. I know you only changed to 225px from the 220px (which is actually the current default value for an infobox image), but this is why I reverted your change as being understood to be entirely good faith. There are more articles using absolute values for images, columns, etc. than aren't, and being dependent on volunteers means that it will take years to find a solution that suits (that is, to rectify this presentation problem). What I had in mind was WP:IMAGESIZE and MOS:UPRIGHT. As you're interested in image sizing, perhaps this is something you'd like to look at as being part of your copyediting? Of course, it's absolutely your WP:CHOICE, but every contributor occasionally doing a little to assists in fixing image issues is a huge help! Hope that helps to clarify my objection. It was most certainly not intended as any form of admonishment, and apologise if I caused you offence. Iryna Harpy (talk) 00:00, 1 July 2019 (UTC)

I'll just add my two cents here: I don't think that triplet of images should have been added there in the first place: the left and middle images are almost totally redundant and there's no need for the article to include both of them, and the figure captions contain almost no useful information at all ("context" and "closeup" are not informative captions). I don't necessarily object to having an image of the M87 galaxy in here somewhere, but I'm not convinced that it's necessary either, and the EHT image is already shown in the lead section. So I'll propose the possibility of removing that 3-panel image set altogether and opening a discussion about whether there's a more informative and clear way to get the key points across with some other arrangement of images. Aldebarium (talk) 01:03, 1 July 2019 (UTC)

Well, they do meet with WP:PERTINENCE to a degree but, frankly, I think that multiple images are overused site wide. If it were put to a !vote, I'd say that the article is well illustrated with images throughout on a section by section basis, and that one image at this point would be ample. For readers interested in more images on the subject, that's what the sister projects template is for. I guess this comes down to consensus based on WP:ITSINTERESTING/WP:ITSIMPORTANT. My preference is merely a preference. Seeing that it has been brought up, other opinions are most welcome. Someone decided to introduce 3 images and it became consensus by default, but consensus can change. Iryna Harpy (talk) 04:37, 1 July 2019 (UTC)

Are there Supermassive Black Holes at the Heart of All Galaxies?

This article refers to "cosmologists believe that supermassive black holes are at the center of most galaxies". WRONG. Cosmologists believe that there may be a SBH at the heart of every galaxy. We've only just observed Sagittarius A at the heart of our Milky Way Galaxy, others are following. 73.85.200.178 (talk) 18:18, 24 September 2019 (UTC)

 Done as per Stuart Clark (2016). The Unknown Universe: A New Exploration of Time, Space, and Modern Cosmology. Pegasus Books. pp. 92–. ISBN 978-1-68177-193-9..--Moxy 🍁 22:32, 24 September 2019 (UTC)

This isn't the case. We have discovered galaxies without supermassive black holes in their centers. See, for example, A2261-BCG. –Prototime (talk · contribs) 22:40, 24 September 2019 (UTC)

And even if we hadn't, we shouldn't write blanket statements about every galaxy in the universe. That would be a little silly. XOR'easter (talk) 23:02, 24 September 2019 (UTC)

Disappointed to see our article be so conclusive when we are still in the middle of finding something or lack there of...search for. ......--Moxy 🍁 23:10, 24 September 2019 (UTC)

For another example, there's M33, which quite possibly has never had a supermassive black hole. The statement "cosmologists believe that supermassive black holes are at the center of most galaxies" reflects the astronomical consensus; the proposed modification does not. Oversimplification is the job of pop science, not an encyclopedia. XOR'easter (talk) 23:43, 24 September 2019 (UTC)

The Meissner effect for black holes

Gürlebeck and Scholtz have shown in 2018 that electric and magnetic fields are expelled from black hole horizons, similar to superconductors (Meissner effect). I think this property should be mentioned in the article (in § Physical properties or § Event horizon), but I'm not confident enough to do it myself and therefore ask the regular maintainers of the article to do it. — UnladenSwallow (talk) 16:33, 7 October 2019 (UTC)

References

Transfer of black hole's energy to external radiation

The article only mentions black holes absorbing radiation. Cardoso and Vicente have recently shown that a black hole moving at a relativistic speed deposits its energy in the external radiation, reflecting it 180° in its direction of movement, producing "a ring of fire" ${\textstyle 1.05\ r_{s}\leq r\leq 1.55\ r_{s}}$. Then there's the recent "halo drive" idea to extract energy from a pair of black holes or a fast-rotating black hole by sending light around. I think we should at least mention the fact that in certain situations a black hole may deposit more energy in external radiation than it absorbs. — UnladenSwallow (talk) 22:48, 7 October 2019 (UTC)

These are kinetic interactions, they depend on the BH moving quickly relative to something else. That's not a special property of black holes, though their ability to slingshot light 180° might be unique. VQuakr (talk) 16:12, 15 October 2019 (UTC)

References

File:Black hole - Messier 87 crop max res.jpg to appear as POTD soon

Hello! This is a note to let the editors of this article know that File:Black hole - Messier 87 crop max res.jpg will be appearing as picture of the day on December 21, 2019. You can view and edit the POTD blurb at Template:POTD/2019-12-21. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! Cwmhiraeth (talk) 11:01, 10 December 2019 (UTC)

Picture of the day

A black hole is a region of spacetime exhibiting gravitational acceleration so strong that nothing – no particles or even electromagnetic radiation such as light – can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed.

This picture is a photograph of the shadow of the supermassive black hole at the centre of the Messier 87 (M87) elliptical galaxy in the constellation Virgo, as captured on 11 April 2017 by the Event Horizon Telescope, a planet-scale array of eight ground-based radio telescopes, a collaborative effort by scientists from over 20 countries; the photograph itself was released on 10 April 2019. As a black hole is a completely dark object from which no light escapes, its shadow is the next best alternative to an image of the black hole itself. The event horizon, from which the telescope takes its name, is around 2.5 times smaller than the shadow it casts and measures just under 40 billion kilometres (25 billion miles) across.Photograph credit: Event Horizon Telescope

Semi-protected edit request on 10 December 2019

Change

After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M☉) may form.

to

Another category of these objects are supermassive black holes of millions of solar masses (M☉).

COMMENT: PLEASE ASK ANY ASTROPHYSICIST (I AM THE ONE FROM POLAND) - SUPERMASSIVE BLACK HOLES DO NOT FORM FROM THE ONES OF SOLAR MASSES, ESPECIALLY IN THE MODERN UNIVERSE - THEY HAVE FORMED BILLIONS YEARS AGO, NOW "STELLAR" BLACK HOLES LIVE USUALLY QUIETLY FOR BILLIONS OF YEARS TO COME, NO CHANCE TO FORM NEW SUPERMASSIVE BLACK HOLE. THANK YOU FOR THE CHANGE IN ADVANCE! 77.245.247.62 (talk) 08:22, 10 December 2019 (UTC)

 Not done: please provide reliable sources that support the change you want to be made. Unfortunately asking an astrophysicist is not a sufficient source. We need to use a reliable, published source. ‑‑ElHef (Meep?) 16:00, 10 December 2019 (UTC)

Suggestions to make this page more readable

The page should be rewritten with a general reader in mind. Pertinent questions would include: has anyone ever seen a black hole? If so, when was the first sighting made? As it currently stands, the page bogs down in endless details and jargon of theoretical models, without ever really making a persuasive argument that black holes do exist and are not just speculative constructs. -Wwallacee (talk) 11:47, 24 December 2019 (UTC)

There's an entire section of the article devoted to observational evidence of black holes. –Deacon Vorbis (carbon • videos) 12:39, 24 December 2019 (UTC)

And the lede includes a picture. XOR'easter (talk) 15:50, 24 December 2019 (UTC)

Rotating event horizon shape

The last sentence of the event horizon section says "For non-rotating (static) black holes the geometry of the event horizon is precisely spherical, while for rotating black holes the event horizon is oblate."

https://en.wikipedia.org/wiki/Kerr_metric#Important_surfaces provides equations for both the ergosphere and event horizons of a rotating black hole. The equation for the event horizon can only ever describe a perfect sphere (there are no theta or phi terms).

These two things are inconsistent. In my estimation, some people have confused the ergosphere for the event horizon and the second to last sentence of the event horizon section should drop the word "approximately" and the very last sentence should be entirely removed. — Preceding unsigned comment added by 199.116.184.9 (talk) 20:28, 9 January 2020 (UTC)

Done, more or less. The question remaining, which is over my head, is if it's worth discussing non-equilibrium stages during formation. WolfmanSF (talk) 00:15, 10 January 2020 (UTC)

I think this needs further discussion before any change should be made. As Misner, Thorne and Wheeler say, "in general, black holes are not spherical" (Gravitation, p. 899). IIRC, the apparent sphericity is an oversimplification based on a coordinate artifact; see Smarr (1973), the discussion around Eq. (116) of Visser (2007), and Delgado, Herdeiro and Radu (2018). XOR'easter (talk) 00:19, 10 January 2020 (UTC)

Okay, for your sources could you please check the context to confirm that they are specifically discussing the event horizon? Also, (if they are correct) we should change the Kerr_metric and Kerr–Newman_metric pages to use the correct (non-spherical equations) or explain how/that the equations are only approximations.199.116.184.9 (talk) 21:31, 10 January 2020 (UTC)

I double-checked each one to make sure they were taking about the event horizon and not the ergosphere. I agree that the Kerr metric and Kerr–Newman metric pages could stand revision; as best as I can tell, the issue isn't one of approximation per se, but one of translating results from a coordinate system where it is easy to derive results to something that matches what we mean when we say "the shape of the black hole" in everyday language. XOR'easter (talk) 21:51, 10 January 2020 (UTC)

Given that the ref. currently in use for oblateness mainly describes a temporary toroidal geometry that may arise during collapse, I think we might start by replacing that source with the three more relevant ones you have provided. WolfmanSF (talk) 08:38, 12 January 2020 (UTC)

Energy loss, escaping or gaining "negative deposits", and another development suggestion.

@TimothyRias I argued against denying absolutely escape from inside event horizon, for a couple of reasons.

In Stephen Hawking's words, "gravitational collapse produces apparent horizons but no event horizons" and "The absence of event horizons mean that there are no black holes - in the sense of regimes from which light can't escape to infinity." So Hawking has arrived at the conclusion that even ligth could escape, and denied event horizons totally.

The negative energy deposit you mentioned is apparently connected only with Hawking radiation. I do not buy the idea without confirmation that particles (the deposits) having negative mass do exist. Has somebody confirmed the existence of such particle? If not, energy of radiation originates from BH likely transmitted by timespace. It has after all been confirmed that timespace can transmit energy, and information, carried by gravitational waves, and as I know, it has not been confirmed that EH would stop GWs.

I assume, that during the merger ans ringdown phases of binary BH merger, while the matter of both BH's are inside the joint event horizon but the final stable sphere is not formed yet, gravitational waves are still generated and carrying energy out from inside EH.

For this reasons, the phrase "acceleration so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it" is too strict and also commonly seen doubfull. In a fact, GR does not anyway deny energy escape carried by GWs, so the phrase must be missinterpretation.

According to the fundamental gravitational collapse models, an event horizon forms before the singularity of black hole. Thus EH really can exist without BH. It has been calculated that if all the stars in the Milky Way would gradually aggregate towards the galactic center while keeping their proportionate distances from each other, they will all fall within their joint Schwarzschild radius long before they are forced to collide. Up to the collapse in far future, observers in a galaxy surrounded by an event horizon would proceed with their lives normally.

On the other hand, an apparent horizon always implies the existence of BH whereas EH does not, therefore an apparent horizon should be named as defining feature of a black hole, not EH. Yoxxa (talk) 14:02, 28 March 2020 (UTC)

Please provide a strong source that explicitly states that, for example, "gravitational waves are still generated and carrying energy out from inside EH"; if there is no such strong source, we'll have to wait for mainstream science to catch up with you before we can add this to Wikipedia. Rolf H Nelson (talk) 00:28, 29 March 2020 (UTC)

This should be self-evident. According to GR binary black hole mergers always emit energy as gravitational waves, regardless if they have separate or joint event horizons. EHs are only calculated theoretical distances where paths of light are turning inwards, they have no affect to spacetime's form or it's possible changes or vibrations. I'll keep my eyes open if this detailed description would show up in some scientific paper. Yoxxa (talk) 16:34, 30 March 2020 (UTC)

In GR, gravitational waves also cannot escape an event horizon (and also cannot cross an apparent horizon).TR 14:51, 30 March 2020 (UTC)

Please provide a strong source that explicitly states that. Yoxxa (talk) 16:34, 30 March 2020 (UTC)

This will do [2] TR 17:52, 30 March 2020 (UTC)

Numerical BH merger models are skipping the question what is inside horizon, because that is not in the focus of their studies. As the document you referred tells: "Simulations of binary black hole systems using the Spectral Einstein Code (SpEC) are done on a computational domain that excises the regions inside the black holes." "Black hole excision is a means of avoiding the physical singularities that lurk inside black holes. The idea is to solve Einstein’s equations only in the region outside apparent horizons, cutting out the region inside the horizons."

In both separate and unified horizon cases, matters are losing part of their masses emitting it as gravitational waves, hence black holes actually do emit energy. That is my original point and reason for the correction to the page. Yoxxa (talk) 16:19, 31 March 2020 (UTC)

Do you have any sources to back up your claim? Talk pages are not a forum. - Parejkoj (talk) 16:57, 31 March 2020 (UTC)

Indeed WP:FORUM. Also try to understand why excision is a valid strategy.TR 18:28, 31 March 2020 (UTC)

Will this do? The radiation comes out either from inside separate or joint horizons or both, but it does, and joint mass-energy has decreased by out radiated energy. Can there just be any stronger source? Yoxxa (talk) 10:19, 1 April 2020 (UTC)

References

Won't do—see wp:CIRCULAR. - DVdm (talk) 12:34, 1 April 2020 (UTC)

Critical remarks on presentation of speculative topics

I think that an encyclopedia, online of otherwise, should mostly describe scientific findings, results and theories which are proven and widely accepted in the scientific community. Speculative scientific publications should not be featured; or if one thinks there is a point in doing so, perhaps because certain topics are trending in the scientific discussion, they should be clearly described as being speculative. I am referring here in particular to the presentation of topics regarding "firewalls" and "information loss". As far as I can see, the presentation of those highly speculative discussions is biased towards a particular point of view which so far ought to be regarded as controversial. The "firewall paradox" isn't generally accepted among physicists, see e.g. the article "Information Loss" by William G. Unruh und Robert M. Wald, published in: Rept.Prog.Phys. 80 (2017) 9, 092002; e-Print: 1703.02140 [hep-th]. At least it should be pointed out in a balanced encyclopedia entry that there is a controversy. Similarly, writing "According to widely accepted research by physicists like Don Page[197][198] and Leonard Susskind..." would be difficult to verify as to the statement "widely accepted". For my taste, this reads too much like a promotional piece towards a certain point of view among several on a highly speculative, unproven and experimentally unexplored part of the frontiers of physics. As pointed out initially, that is not the way of seriously writing about physics in an online encyclopedia. I hope you see the point, and will see yourselves in the position to make due amendments. Yours truefully, Magellanus. — Preceding unsigned comment added by 178.14.42.237 (talk) 22:28, 7 April 2020 (UTC)

The 'widely accepted' may stem from the Nature overview cited at the end of paragraph. What's widely accepted is not the existence of a firewall, but rather that the discovery of the "firewall paradox", that existing semiclassical physics was inconsistent. If there's a less confusing accepted name for the "firewall paradox", we can certainly use it. The Rept.Prog.Phys. doesn't seem to deny the paradox, but rather seems to state that the solution is to abandon unitarity. Feel free to submit an edit if you have a better idea how to phrase it. The section can certainly be trimmed if people think it's WP:UNDUE, but otherwise, if people don't want to read about "open problems" that are (by definition) unproven, they can just skip the section titled "open problems". Rolf H Nelson (talk) 04:47, 8 April 2020 (UTC)

Isn't the "firewall paradox" just another incarnation of the "information paradox"? Ultimately this paradox boils down to that you cannot simultaneously have unitarity, semi-classical quantum field theory at the horizon, and locality without creating some contradiction. The opinions on which to give up differ strongly depending on who you are talking to. The challenge for this page is to provide a neutral overview of these different views. This however is very difficult to do, because the many sources will strongly tend towards on of the solutions.TR 11:41, 8 April 2020 (UTC)

They are related, but logically distinct. Susskind's original black hole complementarity proposal satisfied the information paradox but not the firewall paradox. Rolf H Nelson (talk) 22:27, 11 April 2020 (UTC)

I should add that Unruh and Wald emphasize that "unitary", at least in the sense it is commonly used by the proponents of "firewall" ideas, is not as fundamental as it is often portrayed, and that in certain situations - such as those discussed in black hole evaporation - a breakdown of unitarity is not equivalent to leaving the framework of quantum mechanics (or quantum field theory) per se. Anyway, giving a balanced account of the discussion admittedly is difficult. I agree that very different opinions on that topic are held in various quarters of the theoretical physics community. I may think about it and propose a more neutral (from my perspective) formulation of the matter. However, for the time being, a fix could be to cite the paper by Unruh and Wald as the main source of prominent voices of a critical position towards firewalls, together with the comment that the issue isn't settled and subject to current research in theoretical physics. Yours truefully, Magellanus — Preceding unsigned comment added by 178.14.68.29 (talk) 15:17, 8 April 2020 (UTC)

I'd be happy with changing This creates a paradox to This seemingly creates a paradox and adding a sentence like, Which, if any, of these assumptions should be abandoned remains a topic of debate. XOR'easter (talk) 23:04, 8 April 2020 (UTC)

[3] "In order to resolve the paradox": which one, the information loss or the firewall paradox? Rolf H Nelson (talk) 22:27, 11 April 2020 (UTC)

Not a good sign when the first sentence is wrong

The article starts with "A black hole is a region of spacetime exhibiting gravitational attraction so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it" and citing the book by Wald. But in the same book, the next sentence says "However this notion is not properly captured by defining a black hole". It's not fair for a so good book to cite it wrongly. The horizon is not about how strong is gravity. For a supermassive BH, gravity could be very weak at the horizon while for a small black hole any object would be destroyed by tidal forces long time before reaching horizon. SO NO, horizon is not about how strong is gravity. In relativity, time is fundamental component, without it, one can't understand. Time is also affected and therefore the future light cone, which rotates toward the interior of the black hole. Once an observer reaches the horizon, his future is inside the black hole. It's not about how strong is gravity but about deforming the causal structure. — Preceding unsigned comment added by 201.241.20.145 (talk) 02:07, 13 April 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.

The first sentence does not say that the horizon is about how strong gravity is. It does not even mention the horizon, so I don't think there's a problem with it. Your objection is covered by one of the following sentences, and further down in the article. - DVdm (talk) 07:19, 13 April 2020 (UTC)

Note that the first sentence does not mention "gravitational force" or "gravitational field" being strong. It says "gravitational attraction" this is purposefully a bit vague, to cover the much more technical description of curvature of spacetime leading to the formation of trapped surfaces and a event horizon, which are accurately (but in precisely) covered by the accessible description "strong gravitational attraction".TR 11:06, 13 April 2020 (UTC)

I don't personally like it either, I'd prefer something like "with a strong gravitational field that nothing can escape from", but the current text is well-sourced, so we should just leave it unless someone has a strong source that words it better. In any case, I don't think it's actually causing anyone to be confused about the basic idea of what a typical black hole is.

There's also some room for a "black hole for laymen" article that explains the causal structure in a more accessible way, either by expanding https://simple.wikipedia.org/wiki/Black_hole or creating an article in the Category:Introductory articles series.Rolf H Nelson (talk) 06:30, 14 April 2020 (UTC)

Note that a statement like "with a strong gravitational field that nothing can escape from" is categorically wrong for the reasons mentioned by the IP above. The gravitational field at the horizon can be quite weak.TR 13:46, 14 April 2020 (UTC)

Sure, but the horizon is not mentioned. - DVdm (talk) 13:59, 14 April 2020 (UTC)

Nonetheless, the strength of the gravitational field has nothing to do with things not being able to escape.TR 16:54, 14 April 2020 (UTC)

But the opening sentence does not mention the gravitational field either, let alone its strength. It looks like Wald gave that line quite some thought . - DVdm (talk) 17:02, 14 April 2020 (UTC)

Exactly, which is why I was commenting that changing it to something like "with a strong gravitational field that nothing can escape from", as was suggested, would be bad.TR 17:28, 14 April 2020 (UTC)

Ok, and good one, this. - DVdm (talk) 17:58, 14 April 2020 (UTC)

Yeah, fair point on that one. Ceoil (talk) 02:46, 16 April 2020 (UTC)

Full protection

Ceoil, Deacon Vorbis, please resolve your dispute in the usual way, through talk page discussion. Thank you. El_C 02:21, 16 April 2020 (UTC)

Its seems to me you dont understand the tools you are wielding. Protection against a two well established editors? Ceoil (talk) 02:44, 16 April 2020 (UTC)

Yes, Ceoil. Established editors do not get to edit war, just the same as newcomers. El_C 02:45, 16 April 2020 (UTC)

Ok, but this is becoming tedious, my original point on your talk stands: if you dont understand the tool or the rules, best say nothing. DVdm, no offence to you at this point. Ceoil (talk) 02:48, 16 April 2020 (UTC)

I realize you wish to make me the target of your frustration, but that makes it neither fair nor reasonable. El_C 02:50, 16 April 2020 (UTC)

i'd prefer if you went back to DVdm's version and lifted full protection; my additions were only matters of style, I thought. You overshot here, with no appreciation of content protection. Ceoil (talk) 02:55, 16 April 2020 (UTC)

I saw an edit war where exceeding 3RR by the participants was a real risk, so I acted quickly. I thought that was to my credit. Anyway, happy to oblige. El_C 02:56, 16 April 2020 (UTC)

Semi-protected edit request on 12 June 2020

In the last paragraph of the introduction please chenge "On 11 February 2016, the LIGO collaboration announced the first direct detection of gravitational waves," with "On 11 February 2016, the LIGO and Virgo collaboration announced the first direct detection of gravitational waves, Geppo.Cagnoli (talk) 09:14, 12 June 2020 (UTC)

 Done: [4]. - DVdm (talk) 09:25, 12 June 2020 (UTC)

It's "shredded", not “shred"

The fourth paragraph contains the word "shred" used as a past tense. This should be "shredded".50.205.142.50 (talk) 15:46, 24 June 2020 (UTC)

No, it's being used as a past participle rather than a simple past tense, and both shred and shredded can be used in that sense. –Deacon Vorbis (carbon • videos) 15:51, 24 June 2020 (UTC)

Doesn't look like its being used as a past participle to me. The sentence: "Stars passing too close to a supermassive black hole can be shred into streamers that shine very brightly before being "swallowed." has the simple sentence "Stars can be shred." The main verb, "can be shred", is present tense in the potential mood which is made with auxiliary verbs plus the infinitive verb form ("to shred" without the "to"). Were you to rewrite the sentence out of the potential mood in the the indicative mood, the main verb "can be shred" would change to "are shred".Tachypaidia (talk) 14:21, 14 July 2020 (UTC)

The infinitive here is "be shred", which is passive, which formed from of the appropriate tense of "to be" and the past participle of shred.TR 15:47, 14 July 2020 (UTC)

The infinitive here is "shred" with it marked periphrastically for the passive voice with "be". Regrettably, this is often omitted in spoken English, such as "the chicken is too hot to eat" which actually means something else than what is commonly intended. — Preceding unsigned comment added by Tachypaidia (talk • contribs) 07:31, 15 July 2020 (UTC)

Please consider the use of subjunctive mood in scientific writing: —Beast: "He's speaking the truth." Beast's owner: "How do you know?" Beast: "He's speaking in the subjunctive." —The Star Beast (Robert Heinlein). In other words, the article's text can be read in subjunctive mood, meaning that the article text "be shred" deals with possibility, which is an appropriate way to state an inference. --Ancheta Wis   (talk | contribs) 19:40, 14 July 2020 (UTC)

Semi-protected edit request on 22 July 2020

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[b]Black hole in mythology[/b]

Black hole in Puranas is called as third eye of god Shiva & also called as Vishnu Chakra Or Krishna Chakra - Black hole is also known as Goloka abode of god Krishna. Gita Says abode of god Krishna is where light cannot reach.

Black hole in Puranas is also known as Rudras - Puranas Says there are countless Rudras but only 11th(Eleventh) Rudra is known as god Shiva. God Krishna says in Gita that I am god Shiva.

In Ramayan god Rama was king for 11,000(Eleven Thousand) years & some Ramayan says nobody knows how many years god Rama was king - It means god Rama was immortal & he is still king & he is Still Living Somewhere. It means god Rama was avtar of god Shiva. There is no other information of 11th(Eleventh) number found in any texts books of hindu mythology.

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Please Remove These Lines

I Have Studied At Least 200 Books On Hindu Mythology.

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Please Remove These Lines Vikram ght (talk) 14:29, 22 July 2020 (UTC)

 Already done. These line don't appear in the article, so there's nothing to remove. –Deacon Vorbis (carbon • videos) 14:35, 22 July 2020 (UTC)

Supernovae

Do my eyes deceive me? Is there no mention of the word "supernova" in the entire article? Lithopsian (talk) 19:37, 27 August 2020 (UTC)

I have just added some info and a link to supernova, in the gravitational collapse part. --JimenaAstro (talk) 22:11, 27 August 2020 (UTC)JimenaAstro

I removed part of what you added because it included an incorrect definition of what a planetary nebula is. Planetary nebulae are not supernova remnants and they aren't related to black hole formation. It would still be useful to have a little more text on the connection between supernovae and black hole formation though. Aldebarium (talk) 22:21, 27 August 2020 (UTC)

I just (preliminary) restored properly sourced content that was removed by user Aldebarium (talk · contribs). Comments welcome. - DVdm (talk) 22:26, 27 August 2020 (UTC)

Hi Aldebarium (talk · contribs), thank you for your comments and edits. The mention to planetary nebulae was there before, I did not add it. I just expanded on the supernova event, but did not feel like removing the planetary part completely. I agree that planetary nebulae are not supernova remnants (and are not related to black hole formation). I added a brief mention to supernova in the introduction and will now have a look at the gravitational collapse part to see how we can express it better. Thank you! JimenaAstro (talk) 22:32, 27 August 2020 (UTC)JimenaAstro

OK- sorry then, I misunderstood where that text came from. I agree with including more information on the connection between supernovae and black hole formation in general, so my main reason for the deletion was just to remove the incorrect stuff about planetary nebulae. Aldebarium (talk) —Preceding undated comment added 22:35, 27 August 2020 (UTC)

 Jood job here! - DVdm (talk) 22:37, 27 August 2020 (UTC)

Aldebarium (talk · contribs) Please try to conform closer to what's directly stated in reliable sources. Rolf H Nelson (talk) 05:04, 28 August 2020 (UTC)

I'm not sure what you're referring to, but if you mean the part about Type Ia supernovae, I was working on removing that in my next edit. I didn't write that, it was there before, and I agree it doesn't belong there. Aldebarium (talk) 05:07, 28 August 2020 (UTC)

It would probably be appropriate to also mention something about the (upper) mass gap that sets an effective maximum mass for stellar black holes.TR 06:49, 28 August 2020 (UTC)

Semi-protected edit request on 7 October 2020

Recently, a quantum thermodynamical description for the interior of a Reissner-Nordström black hole, was proposed by Musmarra and Bellini. J. I. Musmarra, M. Bellini. "Quantum thermodynamics in the interior of a Reissner-Nordström black-hole". Physics of the Dark Universe. vol. 30, 100710 (2020).[5]. Mago.ratanga (talk) 22:55, 7 October 2020 (UTC)

 Not done. It's not clear what changes you want to make. –Deacon Vorbis (carbon • videos) 22:56, 7 October 2020 (UTC)

Temperature proportionality

Regarding this and this edit by user Spyglasses and this and this revert by user Deacon Vorbis, see Kip Thorne who writes that Hawking concluded that the temperature is proportional to the hole's surface gravity. So it looks like Deacon Vorbis is correct. - DVdm (talk) 14:17, 10 October 2020 (UTC)

References

Semi-protected edit request on 3 November 2020

The reference no. 177 Shipman, H. L.; Yu, Z; Du, Y.W (1 January 1975). "The implausible history of triple star models for Cygnus X-1 Evidence for a black hole". Astrophysical Letters.

 is incorrect in detail: Shipman appears to be the single author of the article, see

https://ui.adsabs.harvard.edu/abs/1975ApL....16....9S/abstract

It should read e.g.

Shipman, H. L. (February 1975). "The implausible history of triple star models for Cygnus X-1 Evidence for a black hole". Astrophysical Letters. Intophysics (talk) 19:22, 3 November 2020 (UTC)

Agreed. Looks like the doi link is bad? VQuakr (talk) 20:02, 3 November 2020 (UTC)

 Done Fixed. XOR'easter (talk) 20:14, 3 November 2020 (UTC)

Black hole definition refinement

According to me, the current definition for a black hole ("A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.") should be refined to be able to cope with the observations of two black holes merging together. According to the current definition, recently observerd merging of black holes would not possible since none of the merging black holes would be able to loose matter to the other black hole. The refinement could be something like: "without the nearby presence of any other significant object". WDeeraa (talk) 23:47, 26 January 2021 (UTC)

If some reliable source would directly support that, there would be no problem to add it. Without a source this would be wp:original research, which is not allowed on Wikipedia. - DVdm (talk) 00:02, 27 January 2021 (UTC)

Definitions are arbitrary. We already have List of gravitational wave observations, LIGO observations of inspiral events, which document mergers of black holes with other black holes (such as GW150914), and other mergers of black holes with neutron stars, etc. In other words, these objects are observed to entrap each other; there is no need for definitions to allow their existence. --Ancheta Wis   (talk | contribs) 01:56, 27 January 2021 (UTC)

In a BBH merger nothing escapes from within the black holes. There is no need to change anything.TR 13:29, 27 January 2021 (UTC)

In a Binary Black Hole system you could argue that nothing escapes between the two black holes (although I believe that the ultra-strong gravitational fields will influence each other, therefore also both event horizons, which will allow exchange of matter at a certain stage).

But when the two black holes merge to become one bigger black hole, the current definition of a black hole does not hold.

Also since the mass of the resulting black hole is less than the sum of the two merging black holes (for example GW190521: 85 M_☉ + 66 M_☉ → 142 M_☉), there is a significant loss of mass which cannot be explained with the current definition.

Maybe the addition of a note to solve the lack of a source? WDeeraa (talk) 21:54, 28 January 2021 (UTC)

We solve the lack of a source by not doing adding the content. All content, including footnotes, needs to be verifiable. VQuakr (talk) 22:13, 28 January 2021 (UTC)

I repeat, there is nothing wrong with the current description of a black hole as "a region of spacetime from which nothing can escape", in the case of merging black holes. In fact, this remaining true is instrumental in certain approaches to numerical relativity used to model such a merger. If you wish to claim otherwise you will need to provide a source.TR 15:37, 29 January 2021 (UTC)

Semi-protected edit request on 7 February 2021

We need to add Paul Murdin's wiki page this Wiki page. Basically, changing 'Paul Murdin' in this article to a link to his page. 213.104.97.175 (talk) 23:18, 7 February 2021 (UTC)

 Done. ◢  Ganbaruby!  (Say hi!) 00:35, 8 February 2021 (UTC)

New image

Should a section be added about imaging of black holes and should the latest image of a black hole be added? ([6]) Cynosure-NULL (talk) 21:11, 26 March 2021 (UTC)

IMHO any in-depth coverage (that is, beyond a sentence or two) of the EHT Messier 87 imagings should go under Event_Horizon_Telescope#Messier_87* instead. Rolf H Nelson (talk) 20:56, 27 March 2021 (UTC)

Alternatives section

I suggest that the Alternatives subheading should get its own separate section, outside of the Observational Evidence section. Reason being, alternatives are more theoretical rather than observational. If not a separate section, perhaps a subheading under Open Questions. Assambrew (talk) 19:42, 15 April 2021 (UTC)

I tend to agree. The current organization dates back to a time when the observational evidence was much more circumstancial, and this subsection served as a summary of alternative hypotheses for the available observational evidence (at the time). We now have pretty overwhelming evidence from various sources (e.g. LIGO and the EHT), and this organization is a bit dated. The section would also benefit from a critical update.TR 14:20, 16 April 2021 (UTC)

Okay, I pulled Alternatives to a new separate section. Actually the alternative hypotheses are mostly theoretical, so perhaps not much affected by the observational evidence yet. Assambrew (talk) 18:05, 16 April 2021 (UTC)

Black hole radiation

Hi all - not my field whatsoever, but I have read a bit about Hawking raditation. The beginning part of this wiki states that no electromagnetic radiation is emitted from a black hole. Should this be highlighted to show that, within the theory of Hawking radiation, this might not be completely true? Jamzze (talk) 10:25, 15 May 2021 (UTC)

It does not say that no radiation is emitted. It says that none escapes (from inside). It then says that Hawking radiation is emitted from the horizon. This is correct according to mainstream theory.Weburbia (talk) 12:18, 15 May 2021 (UTC)

Microlensing

Hello, I think the subsection on microlensing as a tool for detecting black holes can be updated with these two works: Wyrzykowski et al. 2016 and Wyrzykowski & Mandel 2020. I am not familiar with what is an acceptable or unacceptable source for Wikipedia, or how exactly one is supposed to do that, but if someone could look into it, that would be great.

109.196.56.137 (talk) 22:36, 14 July 2021 (UTC)

NASA Observes emissions from a black holes

The information should be updated to reflect the new Data. Parabox888 (talk) 16:57, 22 July 2021 (UTC) https://www.physics-astronomy.org/2021/06/nasa-saw-something-come-out-of-black.html

Semi-protected edit request on 21 September 2021

UserQUASARS (talk) 05:31, 21 September 2021 (UTC)
      New ideas and theories can rise in everybody's mind but it needs an angle to rearrange.
      I have a new theory about thinking of dark matter everyone knows that dark matter is not visible it's just a form of energy.
      I'm also amazed on thinking that dark matter is in black hole's layer because when you see the black hole it emit something gravitational or magnetic field repealing light which changes the light from a straight line and makes a arc or like a curve then we can see it it as the light moving around the black hole but it is not true.
     It must be an three dimensional object because then we can see the light moving around.It is the darkest object in the universe as we know dark colour absorbs more heat then why not the black holes absorbs heat or light then it must have a greater shield which do not pass the light inside the black holes and we know that dark matter never comes in contact and they are the special ones to create galaxies and black holes can do exactly the same work then why don't we say that black holes are dark matter because dark matter repels the light.
            I hope this theory is true because it is the most accurate theory I had ever been thought.
            🤔I thought it🤔much more🤔 — Preceding unsigned comment added by UserQUASARS (talk • contribs) 07:31, 21 September 2021 (UTC)

 Not done. See WP:OR. ◢  Ganbaruby!  (talk) 06:13, 21 September 2021 (UTC)

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): NIanni727, Jonathanp44.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 15:54, 16 January 2022 (UTC)

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Sbaig13. Peer reviewers: Sbaig13.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 18:08, 17 January 2022 (UTC)

A Commons file used on this page or its Wikidata item has been nominated for speedy deletion

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for speedy deletion:

• Luminet's Simulation of a Black Hole Accretion Disk.jpg

You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 21:07, 17 January 2022 (UTC)

Semi-protected edit request on 20 January 2022

I would like to edit because some of this is false information. I work for N.A.S.A and I know that this is untrue. Naruto Lord 7th Hokage (talk) 21:01, 20 January 2022 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Nthep (talk) 21:07, 20 January 2022 (UTC)

Grammatical Errors

There are some grammatical errors in the first paragraph. If possible I'd request someone to look into this matter and fix them. Bunnyman13 (talk) 12:17, 11 April 2022 (UTC)

I reverted edits by Sabbir Sadik Omi Sso (talk · contribs) which should fix the above problems. Plumbum208 (talk) 12:26, 11 April 2022 (UTC)

Semi-protected edit request on 11 April 2022

1. Prepositional fault: change "A black hole is a region in spacetime" to "A black hole is a region of spacetime"

2. Prepositional fault : change "such as light — can escape through it" to "such as light — can escape from it"

3. Prepositional fault : change "The boundary within no escape" to "The boundary of no escape"

4. 103.67.157.236 (talk) 10:09, 11 April 2022 (UTC)

 Done, see next section. Plumbum208 (talk) 12:27, 11 April 2022 (UTC)