<article_title>Black_hole</article_title>
<edit_user>TimothyRias</edit_user>
<edit_time>Wednesday, February 9, 2011 12:32:33 PM CET</edit_time>
<edit_comment>/* X-ray binaries */ ref clean up</edit_comment>
<edit_text>The first strong candidate for a black hole, Cygnus X-1, was discovered in this way by Charles Thomas Bolton&lt;ref&gt;&lt;/ref&gt; and [[Louise <strong><strike>Webster|</strike></strong>Webster]] and Murdin&lt;ref&gt;&lt;/ref&gt; in 1972.&lt;ref&gt;{{Cite book |last=Rolston|first=Bruce|date=10 November 1997</edit_text>
<turn_user>Seneika<turn_user>
<turn_time>Tuesday, February 8, 2011 1:02:15 PM CET</turn_time>
<turn_topicname>Other suggestions</turn_topicname>
<turn_topictext>It seems to me that sections 2,3 and 5 are affine. They're all about theory of black holes. I think merging them into a major section called 'Theory' would be nice. The usage of subsubsections may not be a bad idea. Take for example this (featured) article about acetic acid. My suggestion is to structure the article in the form History
Theory: current sections 2,3 and 5 and perhaps a subsection entitled 'concurrent theories'
Observation: the current section 4 plus a section entitled 'Missions' (or a more appropriate title)
This 'concurrent theories' subsections may be a good idea to tell a little about of how other theories handle the concept of black holes. (Alternative theories is not really my expertise, so I think I couldn't contribute here for the moment, although I think they worth being mentioned) In this 'Missions' subsection I'm proposing one would list projects related and/or dedicated to BH observation. As well as other sources of BH detection. There's no mention to gravitational waves in the article. Was it decided to be kept that way? Cheers. --Seneika (talk) 13:08, 2 February 2011 (UTC) Could you elaborate what you think is the added value of this reorganization?As for gravitational waves, I'm not sure what you want to mention about them. Since, no gravitational waves have been detected to date, they do not provide any real additional data on black holes. As for black hole mergers as a source of gravitational waves, that seems to be a subject better covered in the gravitational wave article.As for further expansion with a "missions" section. The article already is fairly long, so I'm hesitant for further expansion. It may be worth while to consider if such discussions are better off in stellar black hole, X-ray binary or supermassive black hole, since missions typically try to observe a very specific class of objects.TR 14:47, 2 February 2011 (UTC)I think a reorganization (not necessarily the one I've proposed) would help to make the article cleaner. Separating more clearly theory from observational fact. (Don't you agree that section 4.6 is kind of misplaced?)Many theoretical aspects are used to explain what is observed about BHs, (many) other aspects, however, are (highly theoretical) predictions. IMHO this could be separated in a more logical way since little of what one reads in sections 2 and 3 are observational facts (although these are indeed facts about BHs). The structure of a BH fits better in 'theory'. The same is valid for 'Open questions'. Most of these topics are better discussed in their own respective articles.You seem to be concerned in adding here only 'real additional' information about BHs. From this POV I can't attest the relevance of GWs. It was just a suggestion. (But it seems that in the near future gravitational radiation will most likely to be detected than thermal radiation from black holes, for example. Oscilatory normal modes of BHs is an active field of research that can lead to BHs 'finger prints').In this same philosophy one can't attest the 'practical' relevance of any of those results arising from the semi-classical approaches (quantum evaporation, for example), yet these are found in this article (for the sake of completeness, I imagine).About this 'missions' section it could be as little as a paragraph (smaller, for example, than section 5). Just a few comments about common sources of data on BHs. In sum I think a reorganization would add the value of sections more clearly separated by their nature (history, theory and observation) resulting in a cleaner article. Please don't interpret me as some one just arriving here with parachutes and saying whatever I want. I'm just pointing things I think could improve the article and, what is more important, I'm offering myself to do things, not just saying people to do it. --Seneika (talk) 16:47, 2 February 2011 (UTC)I actually think that the organization of the article is pretty clear. (Of course, I am biased in that respect, since I'm responsible for a lot of the current organization.) The first section provides a clear context of the subject by discussing its history. The second answers the "What", what is a black hole and what are its properties. The third answer the "How" and "When" questions; How and under what conditions do black holes originate. The fourth section section then explains what observational evidence exists for black holes. Section 4.6 is very much in its place, since it highlights the various caveats of the observational evidence. The last section then discusses several topics of current research. By nature, this discussions will be more technical than the previous sections, a best practice for technical articles is to have the most technical sections as last. This helps with the general accessibility.About gravitational waves, as it stands the possibility of detecting anything using GWs is based on a lot of wishful thinking, given that no GWs have been detected to date. As such any speculation on what might be learned using GWs seems more in its place in the article on GWs and GW detectors. Once detection of GWs has become a reality, which might be soon, it might also be time to have a blurb here.TR 17:11, 2 February 2011 (UTC) Despite my opinion that this is something that can't be, I thought at first that this article were intended to be relied mainly in 'astrophysical BHs'. I got this idea first reading the lead, were there's no reference to any theory (and by any I mean 'GR', since it's the only one reliably theory on the subject, according to the mainstream of Physics) ruling the definitions and concepts being proposed; and later our discussion confirmed that idea. In practice, however, this article deals with a wide range of aspects regarding BHs. Not just what is observed and I agree this would be an impossibility, since most of the subject is highly theoretical. In fact, most of these topics are strongly hypothetical. Take, for example, the case of the gravitational singularity inside a BH, whose existence or not is a matter of debate that extrapolates the realm of astronomy or astrophysics, since observation would be impossible by definition. Other examples range from inter-universe travel, to quantum evaporation (or vice-versa). These are examples of topics often appearing when one talks of BHs. In the present article this is no different, they're are here as well. In this article it appears to be room left for topics not of only hypothetical nature but also especulative. This is easily seen in a sentence like A phase of free quarks at high density might allow the existence of dense quark stars,[107] and some supersymmetric models predict the existence of Q stars.[108] Some extensions of the standard model posit the existence of preons as fundamental building blocks of quarks and leptons which could hypothetically form preon stars.[109] Supersymetric models or anything outside the standard model is controversial isn't it? This is an example of a highly especulative subject appearing in the present article. Not to mention 'the possibility of travelling to another universe'. Not that I want to advocate in favor of GWs, but when you say Once detection of GWs has become a reality, which might be soon, it might also be time to have a blurb here. I must ask why 'supersymetric models', 'extensions of the standard models' and even predictions of semi-classical approaches have a blurb here without having become 'reality' first. Did the level of 'wishful thinking' related to them garantee that? Isn't it a little arbitrage? When one talks about the structure and evolution of BHs, I think it must be in a different tone of that when one speaks of the structure and evolution of the sun, for example. Although the structure and evolution of 'ordinary' stars are also theory, represented in models, the high number of independent evidences attesting such models in this case allows one to talk about the structure of these stars without explicitly and repeatedly saying that this is theory. The same doesn't apply in the case of BHs. When you say that The second answers the "What", what is a black hole and what are its properties. it can't be left unclear that 'its properties' do not reffer necessarily to observed properties of BHs. As many of such properties are simply not observable and some are even hypothetical, it's not clear what is this 'what' being answered. For this reason I still suggest the existence of the section entitled 'Theory' with what is now section 2 being a subsection of it. I'm not sure about what question is subsection 3.4 answering. (What 'when'?) The whole of subsection 4.6 relies in highly especulative subjects. I'm still not convinced that it is in it's right place. There's already section 5 for 'Open questions'. Off course, all this annoyance of mine stops making sense when one admits this article as a portal to whatever is related to BHs. But this is also not clear. --Seneika (talk) 22:57, 3 February 2011 (UTC) The article tries to cover all aspects of BHs. Since most of what has been written about BHs is of theoretical nature, a lot of the article is concerned with theoretical aspects. (The lead at this point does not reflect this very accurately, which is why I started the section above to improve it.) In fact, the only section concerned with observation is the section called "observational evidence". The current section 4.6 completes the discussion of the observational evidence by relating what the possible alternative explanations are for the observed BH candidates. Part of the point is that any such explanation would require exotic speculative physics. The place of this section is in the "observational evidence" section, since it is about alternative explanations of the evidence, not about alternatives of black holes.Obviously, the subject is very broad, which is why many of the (sub)sections have been written in WP:SUMMARYSTYLE, and refer to a main article for more detail.I'm still not quite clear on what you want to say about GWs in this article. As far as I know, most discussion about BHs and GWs has been in the context of BH mergers as a possibly detectable source of GWs. This is a subject which is much more about GWs than Bhs (for example, if there were other similarly heavy compact objects, their merger would be just as interesting), and is thereby more suited for the GW article. As far as I know, there has been little to no (serious) discussion about using GWs to learn about BHs (unlike for example in cosmology, where you can find quite extensive discussions about what the GW background could teach us if we could the detect it). I could however be wrong about this. If there is documented discussion of this in secondary sources (review papers, textbooks, etc.) this would indeed warrant a short discussion in the "observational evidence" section.I do agree that the article could make it clearer that black holes are a theoretical phenomenon for which we are searching for empirical verification, rather than an empirical phenomenon for which one searches for a theoretical explanation. Improving the lead could help with this.TR 10:03, 4 February 2011 (UTC)I really don't know much about the aspects on which GW and BH subjects cross over each other. The little I know is found in reviews like (apparently this is already found in some textbooks). The picture is like this (I'll omit all the IFs I think should be in what follows, but assume for the moment that GWs and BHs do exist and are those predicted by GR. I'll be short because I know little and to respect the not-a-forum policy) GWs may arrive to Earth comming from the more remote sources. Regardless their origin, GWs can be scattered by BWs. The interaction between GW and BH will cause the last to oscilate. The (quasinormal) modes of oscilation of the BH will be imprinted in the outgoing GW. Different BHs will have different modes of oscilation, scattering GW in their own peculiar way. This is belived (wished, hoped...) to provide a way (presumably the only possible way) to probe the presence of BHs directly.AFAIK, the merger scenary presents a good candidate for detection of GWs. This scenary of scattering of GWs by BHs would present a probe for the presence of BHs. (Off course, GWs must then be assumed to exist). This is why I thought the subject to deserve a comment in this article (and because this seems to be a field of research in activity since the 70's relying in predictions of GR about BHs). Perhaps in section 4.6 then. Seneika (talk) 14:00, 5 February 2011 (UTC) My references autosigned— Preceding unsigned comment added by Seneika (talk • contribs) 00:41, 6 February 2011 (UTC) Note: this ref. to Davies isn't mine. I haven't manage to fix this... Seneika (talk) 00:48, 6 February 2011 (UTC) It appears that there is enough information for a short subsection about the prospects of detecting BHs using gravitational waves, similar to the short subsection about detecting strong gravitational lensing by BHs, one or maybe two paragraphs long. I do not really have time to delve into this right now, so do you maybe feel like drafting a suggestion for such a section?TR 11:48, 6 February 2011 (UTC) Sure. I can do that until the end of the week. Seneika (talk) 13:02, 8 February 2011 (UTC)</turn_topictext>
<turn_text>Sure. I can do that until the end of the week. </turn_text>