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Talk:Quantum Leap

Destination of redirect to be physics concept or television show
A few days ago, the user Jojhutton changed this "quantum leap" redirect page to refer to the article about the Quantum Leap television show rather than the article about the physics concept. I have the strong impression that the concept of a quantum transition in physics, and the colloquial use of the phrase to refer to sudden discontinuous changes in general, is the primary meaning of this phrase (especially with "leap" in lowercase). So I reverted this change. If someone disagrees with my view, this would be a good place to discuss it. —BarrelProof (talk) 01:48, 3 July 2012 (UTC)
 * I will only reiterate what I have already said on my talk page on this matter. The difference between "Quantum Leap" and "Quantum leap" is very slim if not at all. It's only an issue of tense on one letter of one word. The high traffic at "Quantum Leap, (142,000 article views in the past 90 days), compared to Atomic electron transition, (8,000 article views in the past 90 days), means that the collateral damage would be greater with "Quantum leap" redirecting to Atomic electron transition, than would be if the redirect went to Quantum Leap. Also, and I'n not sure exactly, but it looks like the page was moved a while ago to make room for the redirect to Quantum Leap.-- JOJ Hutton  04:21, 8 July 2012 (UTC)
 * The difference between "quantum leap" and "Quantum Leap" is the same as the difference between "red meat" and "Red Meat", and suitable for distinguishing article titles -- see WP:PRECISION. Since the article target of quantum leap must get all the traffic from readers typing in "quantum leap" in the search box and hitting Enter, the stats above show that there is little collateral damage -- most readers reaching the TV show are not first hitting the article target of quantum leap. Instead, targeting the TV show from the lowercase version had the collateral damage of leading all wikilinks to quantum leap to the TV show, when the transition was intended. -- JHunterJ (talk) 12:44, 8 July 2012 (UTC)
 * Then perhaps Red Meat needs to be renamed Red Meat (Comic Strip. Using other Wikipedia articles as sources has hardly ever been the best argument. And you can't compare the two situations since this is not about two "main" articles, but about a Redirect. Leading the redirect to Quantum Leap would have very little collateral damage given the low article traffic the page receives, especially when we have Redirect notice at Quantum Leap. It's about which article is the "Most Likely" article to be searched for. It's obvious from the article view stats that the TV show is the most likely searched for article over the other. Almost 20 to 1.-- JOJ Hutton  15:24, 8 July 2012 (UTC)
 * You've got several points there, so I'm going to bullet them out:
 * If you think there is consensus for a change to WP:PRECISION, Wikipedia talk:Article titles would be the place to see.
 * I used Wikipedia policy and guidelines for the argument.
 * I can compare the situations because the redirect-ness of one of the titles isn't directly relevant to where that title should lead.
 * With the hatnote on Atomic electron transition there is very little collateral damage.
 * I've already answered the note about the stats; given the traffic, it's impossible that more than 8,000 of the 142,000 readers of the TV series article had to suffer the damage of going through "Atomic electron transition" first.
 * Here, though, we could also use WP:RFD to solicit other input on whether this redirect should be retargeted, or WP:RM to move the disambiguation page to the base name. The earlier retargeting to the disambiguation page landed it on the list at WP:MALPLACED, which is where I found it. Cheers! -- JHunterJ (talk) 10:54, 9 July 2012 (UTC)
 * WP:PRECISION is an article naming guideline so it has no bearing since both articles already have their own titles. WP:REDIRECT is more suitable for this topic. One of the criteria is Likely alternative capitalizations. That is obvious here. The stats show the number of article views, they don't tell us how many people were redirected to the pages through the "Redirect". It does however tell us the "most likely" target of readers. You say it's impossible that 8000 of the 142000 readers had to suffer the damage? There are no stats on that. As far as we know, every single reader is being erroneously redirected to "Atomic electron transition". But we don't know that do we either? But the argument "could" be made in the other direction though.
 * Heres something we do know, however, and it's very telling. On and around June 1st, 2012 both article received large spikes in article traffic. Here on Quantum Leap and here at Atomic electron transition. I don't know what caused the spike in traffic, but it's not uncommon to see large spikes when something happens "real world" off Wikipedia. Most likely the same event caused the spike in traffic, and since the redirect at the time was directed to "Atomic electron transition", it's more likely that most of those views at "Atomic electron transition" were based on collateral damage.-- JOJ Hutton  13:54, 9 July 2012 (UTC)
 * Redirects have titles too, and although I see your point, it seems to me the language and reasoning behind the precision guidelines applies easily and correctly to redirects as well. WP:REDIRECT also includes "Reasons for creating and maintaining redirects include: Alternative names, a redirect to the most appropriate article title", which is arguably the case here. And no, I clearly said it's impossible that more than 8,000 of the 142,000 readers did. And if it's 8,000, that means that not one reader was looking for Atomic electron transition. I assume you're not saying that's the case. As for "very telling", there is no corresponding large spike in Quantum Leap (TV series), which tellingly indicates that the redirect traffic is not correlated to the TV series traffic. They are correlated to the atomic electron transition, but that does not indicate that they are "damage". -- JHunterJ (talk) 14:36, 9 July 2012 (UTC)
 * Redirects are not articles and are not bound by the "article title" guidelines of WP:Precision. And besides, I fail to see the logic you are trying to imply with the guideline anyway. Are you saying that "Quantum leap" is the more precise name for Atomic electron transition? A google search of "Quantum leap" reveals far more hits about the television show and other things associated with it, than to anything else. I won't link a result list, I'll let you do your own search with your preferred search engine. I use Yahoo.com quite a lot, but I also did an actual search using Google.com and came to about the same conclusion.
 * Yes WP:REDIRECT also says: '"Reasons for creating and maintaining redirects include: Alternative names''. Is "Quantum leap" really an alternative name for Atomic electron transition? All the sources in the article use the term "Quantum jump". Similar, but not really the same. Or is it that "Quantum jump" is a more common term for Atomic electron transition, than "Quantum leap'? And since, as you pointed out, there are contradicting elements at WP:REDIRECT, it would be more beneficial to error on the side of the article that receives the most article views, which is Quantum Leap by far.
 * As to your comparison to Quantum Leap (TV series), There is no corresponding large spike in that search because nobody searches for an article on Wikipedia by actually typing in that whole phrase. The article views that redirect receives are most likely left over redirected links from inside other articles and therefore obviously wouldn't have the same spike, because its not done through a search, but through clicking on a link.
 * Finally, I linked earlier the article views for June 2012 of both Quantum Leap and Atomic electron transition, both showing a spike in article views on and around the 1st of June. The spike at "Atomic Electron Transition" is very pronounced and makes no sense at all. Theres no reason for it unless you take into account the redirect of "Quantum leap", which corresponds to a similar traffic spike at and around the same time at "Quantum Leap" the TV show. Now if we look back to last year, June of 2011. You will notice that there is a similar article view spike at Quantum Leap on June 1st, 2011. But none at Atomic electron transition for June 1st, 2011. Very curious. Curious because in June 2011, the redirect at "Quantum leap" did not go to "Atomic electron transition", but to "Quantum Leap" the TV show. I don't know why, but for some reason Quantum Leap has received a spike in article traffic on June 1st, two years in a row. Yet Atomic electron transition only received that same spike in traffic the year that "Quantum leap" was a redirect to it, and not the year it was not. The stats do not lie. The television show is the more common and the more searched for topic and should have the redirect.-- JOJ  Hutton  16:57, 9 July 2012 (UTC)
 * The guidelines and policies are not legal contracts to be lawyered. Yes, it's really an alternative name. Your note on the lack of corresponding spike in the TV series article is not indicative of anything -- people don't type it, but nonetheless people end up on the page, which is the hits that the traffic site measures; OTOH we have no measure of what people are typing in the search box to get there. Also, the traffic stats site doesn't distinguish on capitalization, unfortunately: Quantum leap is the same as Quantum Leap. The stats do not lie, nor prove anything in this case. Time for WP:RFD or WP:RM. -- JHunterJ (talk) 17:25, 9 July 2012 (UTC)

I'm not attempting to say that Wikipedia guidelines are contracts, don't know where your inferred that from. You did say earlier, and I quote, I used Wikipedia policy and guidelines for the argument, and I simply countered that argument by pointing out that the guidelines you are linking are not about redirects but about main space articles. If "Quantum leap" is an alternative name for Atomic electron transition, the citations currently being used in the article don't seem to back that up, so simply making a statement to the effect isn't very convincing. Still don't seem to understand your logic of "Quantum Leap (TV series)". The best I can make out is that since there is no spike in that redirect article, you feel that the other stat spikes don't mean anything? Is that it? If so, it's because the spike in the other article is due to a large amount of searches. People type in "Quantum leap" and are redirected to another page. The "Only" way that "Quantum Leap (TV Series)" gets any notable traffic stats is through clicking on blue wikilinks within other articles. They are not searches, but are clicked on links. The spike in traffic on those days is because of a high number of people searching Wikipedia by typing in the little search box. That's all those stats suggest. You have to make the facts fit the theory, not the other way around. I am aware that the traffic stats site does not distinguish tense. The old one did, but this new one does not, so thats no help to either of us.-- JOJ Hutton  18:06, 9 July 2012 (UTC)
 * Request There are not very many reliable sources that link the search term "Quantum leap" with Atomic electron transition. Most of what is found uses the term "Quantum jump", including every source currently used in the article. Unless some hard core sources are found, (sources that are not merely mirror sites), the redirect should be changed back to Quantum Leap, per WP:REDIRECT as it may appear that "Quantum leap" is not an alternative name for AET.-- JOJ Hutton  12:33, 14 July 2012 (UTC)
 * True, not many. There are some, however: The Herald (Glasgow), June 13, 1998, p. 30: "... and occur in quantum leaps. The important feature of a quantum leap is that it is a discontinuous transition between quantum states." I suspect there are fewer reliable sources that link the lower-case "quantum leap" to the TV series, and Atomic state transition mentions the phrase in its broader usage: " in popular discourse, the term "quantum leap" refers to a large increase." You can propose the change at WP:RFD to draw additional input. -- JHunterJ (talk) 13:21, 14 July 2012 (UTC)
 * The lowercase of "quantum leap" is the same two words as the upper save version "Quantum Leap". Search engines do not differentiate.  One author using the term "quantum leap" doesn't override the massive amount of websites and literature linking the two words "quantum leap" with the television show. And apparently the link of the term "quantum leap" with "AET" didn't seem to catch on, since most sources use the term "quantum jump". Also, given the relative amount of time that this page was redirected to Quantum Leap (Over a year) as opposed to your redirect (four months), it should be you that should ask for the RFD, since this I plan on restoring the redirect based on Wikipedia guidelines of WP:REDIRECT, WP:RS, and WP:BRD.-- JOJ  Hutton  13:36, 14 July 2012 (UTC)
 * You disagree with both BarrelProof and me. Also, not "my" redirect, but the one left behind when the physics article was moved from Quantum leap (where it had been since its creation in 2002) to Atomic electron transition by H Padleckas on 11:48, 13 January 2011. -- JHunterJ (talk) 14:21, 14 July 2012 (UTC)
 * It's not as much as disagreeing with the two of you, rather disagreeing with the idea that "Quantum leap" is majorly associated with "AET". Most of the sources are obscure at best. Not many websites, (none that I could find), use the phrase "Quantum leap" in association with "AET". Most, if not all, use the term "Quantum jump". This now becomes a reliable source issue, which is a core content policy, not even a guideline, but a policy. Unless you can come up with some reasoning as to why you feel that "Quantum leap" is more associated with "AET" than with the television show with the exact name, then policies must be adhered to, because it appears the term "Quantum leap" is rarely associated with "AET", if at all.-- JOJ  Hutton  15:42, 14 July 2012 (UTC)
 * I don't think that's the ultimatum or burden here, since it does not appear that the policies are not being adhered to. My reasoning (and BarrelProof's) is above. But here:
 * http://astro.unl.edu/naap/hydrogen/transitions.html
 * http://dictionary.reference.com/browse/quantum+jump
 * http://abyss.uoregon.edu/~js/cosmo/lectures/lec08.html
 * http://www.chem.latech.edu/~deddy/Lectnote/Chap7A.html
 * "Oslo-experiment may explain massive star explosions" (Space Daily, May 23, 2012): "Instead of releasing all the energy in a single quantum leap, the atomic nucleus releases energy in a series of small quantum leaps."
 * "Glass: the laziest liquid of them all?" (Metro (UK), December 5, 2011): "If an electron travelling in the 'slow lane' gains the right amount of energy it will jump up an orbit (known as a quantum leap)."
 * The show does not have this exact name. The show's title has a capital Q and a capital L. Wikipedia page titles are case-sensitive (except for the first letter). -- JHunterJ (talk) 16:17, 14 July 2012 (UTC)
 * There may be a small faction who use "quantum leap" as an afterthought it appears, but how much does the rest of the world seem to care?
 * Google web search results: "Quantum leap" "TV" 4,520,000 hits, "Quantum leap" "Atomic electron transition" 6990 hits. Mostly "mirror" sites.
 * Yahoo web search results: "Quantum leap" "TV" 1,700,000 hits, "Quantum leap" "Atomic electron transition" 43 hits.
 * AOL web search results: "Quantum leap" "TV" 4,520,000 hits, ["Quantum leap" "Atomic electron transition" 4,890 hits.
 * The term "quantum leap" is an afterthought in reference to "AET" and is not the search term used by a great number of people using the web.-- JOJ Hutton  17:16, 14 July 2012 (UTC)
 * I didn't notice any of those that used lowercase "quantum leap" for the TV show, but I admit I didn't look very long. You're right; the rest of the world won't be harmed by the current arrangement, but the internal Wikilinking capability will be harmed by the proposed arrangement, since editors link quantum leap when they intend the physics stuff and Quantum Leap when they intend the TV show. -- JHunterJ (talk) 19:26, 14 July 2012 (UTC)
 * Where do you assume that anyone typing "quantum leap" must be looking for the science? Most people won't capitalize the second word when they type it in looking for the TV show with that exact name, not the science topic that rarely uses "quantum leap" it's references.-- JOJ Hutton  19:43, 14 July 2012 (UTC)
 * I don't assume that the must be. On the other hand, I don't assume that they must be looking for the TV show either. The incoming wikilinks when I addressed the malplaced disambiguation page indicated that it was correctly targeted, and hatnote (and the search box predictions) will get the others to where they're going. Still, a WP:RFD consensus might decide that the lowercase version should go to the TV show as well. I again recommend it to you, since yours is so far the only voice for that change here. -- JHunterJ (talk) 20:59, 14 July 2012 (UTC)
 * The page view numbers, plus the internet search hits, plus the reliables sources, plus the "actual name of the television show" pretty much confirm that "most" people typing in the search bar will be looking for the television show and not "AET". With the current redirect, more people will be redirected to a page in which they are not looking for. While if the redirect was restored, less people, if any, will be redirected to Quantum Leap, if that is not the article that they are looking for. "Quantum leap" appears to be one of those "also known as" type phrases for "AET" anyway. Not used very often. Thats why they moved the page last year in the first place, because it's not a very common name for that particular science. While on the other hand, "Quantum leap" is the actual name for the television show. Whether you want or think that someone will actual type in uppercase for both words is misplaced. Why send someone who actual types in the exact words of the television show to a completely unrelated article, that hardly uses those terms anyway? Can't expect everyone to actually type in uppercase when they are typing. That's why Star wars redirects to Star Wars. Can't nitpick the idea of uppercase and lowercase on this issue, especially when the article you wish to redirect "Quantum leap" to, rarely uses the term in many reliable sources. Furthermore, since we have already established that Quantum Leap gets a far greater amount of page views than Atomic electron transition, it is factual accuracy to conclude that if the page is redirected to "QL",  the greater number of people who type in "Quantum leap" will reach there destination in one click and will not have to see the hat note, than would be if the page is redirected to "AET".-- JOJ  Hutton  22:22, 14 July 2012 (UTC)
 * If its not going to redirect to the actual title of the show using the actual same words in the actual same order, then at least go to a disambiguation page. And Don't revert due solely to "no consensus".-- JOJ Hutton  20:39, 14 August 2012 (UTC)

RfC: Should "[[quantum leap]]" (lowercase "l") redirect to "Quantum Leap" (uppercase "L") or to "Atomic electron transition"
Where should this redirect, redirect to? JOJ Hutton  19:47, 29 August 2012 (UTC)
 * Capitalization differences are used to distinguish common nouns from Titles (Red Meat, red meat) per WP:PRECISION. This should redirect to the primary topic for "quantum leap" (uncapitalized), using the WP:PRIMARYTOPIC criteria. So far, there only criterion met was incoming wikilinks, which I referred to in this edit summary. Is there an indication using those criteria that a different topic should be primary for the lower-case title, or that there is no primary topic for the lower-case title? -- JHunterJ (talk) 12:02, 30 August 2012 (UTC)
 * As I stated in a prior discussion recorded above, I have the strong impression that a "quantum leap" (especially with lowercase "leap") is primarily a physics concept (e.g. ), and that the television show (and other uses of the term) are derivatives of that origin. I suppose that, at the moment, we just have the same three people voicing the same same opinions as in the prior discussion recorded above. —BarrelProof (talk) 19:24, 30 August 2012 (UTC)
 * I took a look at the book that you linked. With the exception of the title (Upper case "L" by the way), do you know how many times the author uses the phrase "Quantum leap" in the book? Zero, nada, not at all. He uses "Quantum mechanics", "Quantum theory", "Quantum Physics", even "Quantum Measurments", but no evidence of Quantum leap. You say that you have a impression that a "quantum leap" (especially with lowercase "leap") is primarily a physics concept and that the television show (and other uses of the term) are derivatives of that origin.  Isn't it possible that the term "Quantum Leap"  is derivative of the television show? Why would an author call his book "Quantum Leap" and then not use the term once in his book? My strong impression is that he is trying to use the popularity of the show to sell his book, or at least the publisher is. This just convinces me more that "Atomic Electron Transition" is not the primary topic of Quantum leap.-- JOJ  Hutton  03:26, 31 August 2012 (UTC)
 * "Isn't it possible that the term 'Quantum Leap' is derivative of the television show?" No. The TV show debuted in 1989. Here's a Google Ngram for the term "quantum leap" before 1989: http://books.google.com/ngrams/graph?content=quantum+leap&year_start=1800&year_end=1988&corpus=0&smoothing=3 . Here's one definition from 1983 and a mention from 1938 and 1923 -- JHunterJ (talk) 11:49, 31 August 2012 (UTC)
 * I am no expert on the Requests for Comment (RfC) process. However, I notice that this particular RfC has been put into the "History and geography" category. That seems rather strange. Personally, I would suggest that it belongs under "Maths, science, and technology" and perhaps "Media, the arts, and architecture". The "History and geography" category seems clearly inappropriate. —BarrelProof (talk) 19:02, 31 August 2012 (UTC)
 * I checked this out solely because it was in the (seemingly) wrong section. Made me wonder. I weakly support moving it to science. I support redirecting the redirect to the TV show. A larger chunk of readers are probably going to be looking for that and an alarmingly growing chunk doesn't capitalize anything, ever. A "For the atomic event(?), see..." should be on the TV article, not the other way around. TV viewers outnumber physicists. InedibleHulk (talk) 01:44, 4 September 2012 (UTC)
 * Thats basically the argument I've been using the whole time.-- JOJ Hutton  01:48, 4 September 2012 (UTC)
 * Yeah, I noticed the mile-long discussion after I commented. I wouldn't have guessed it would be such an issue. Good luck to you, you're on the right side! InedibleHulk (talk) 01:59, 4 September 2012 (UTC)
 * Well it's good to hear that someone independently came to the same conclusion. I'm fairly confident that if this issue was left up to the general wiki-editor, they would come to the same conclusion as well. -- JOJ Hutton  02:25, 4 September 2012 (UTC)
 * The basic problem with that argument is that it's not based on guidelines, like WP:PRECISION or WP:PRIMARYTOPIC. "You're on the right side!" doesn't counter WP:PRECISION. -- JHunterJ (talk) 10:58, 4 September 2012 (UTC)
 * "You're on the right side" wasn't intended as an argument. Just a comment to Hutton. I don't see anything in PRECISION that even applies here. PRIMARYTOPIC seems to favour the show, based on Wikilinks, page views, Google hits and this discussion. InedibleHulk (talk) 19:28, 4 September 2012 (UTC)
 * Those guidelines are for article titles, not redirects. There is no "primary article" called "Quantum leap". It should redirect to the exact phrase, word for word.-- JOJ <sup style="color:#CC9900;">Hutton  11:54, 4 September 2012 (UTC)
 * That's wikilawyering. How does that logic for titles of articles not apply to titles of redirects? Why is the "word for word" (except for capitalization) redirect more beneficial to the encyclopedia than "to the primary topic" redirect? -- JHunterJ (talk) 13:31, 4 September 2012 (UTC)

 * Atomic electron transition per WP:PTOPIC: quantum leap is a physical concept, that was known before the TV show and will be effective afterwards. should be placed at the target though. — Dmitrij D. Czarkoff (talk•track) 13:25, 11 September 2012 (UTC)
 * What part of PTOPIC says anything about physical concepts, prior existence or effectiveness being factors? InedibleHulk (talk) 01:33, 12 September 2012 (UTC)
 * Actually everything, but this part does it particularly clear:
 * Absolutely unambiguous IMO. The other criterion – the more likely target – is also in favor of physics topic, as the TV show is only a likely search target at the places where it was aired, while physics concept is global, referred to from anywhere in the world (including numerous other TV shows).
 * P.S.: The argument "TV viewers outnumber physicists" is ridiculous – the physics article is of no interest to physicists (who know the topic otherwise), so the fair comparison (with both parts equally stretched) is "TV viewers" and "everybody except physicists", which isn't in favor of TV viewers. — Dmitrij D. Czarkoff (talk•track) 07:59, 12 September 2012 (UTC) updated 08:13, 12 September 2012 (UTC)
 * Fair enough. TV viewers outnumber people interested in physics, then. InedibleHulk (talk) 03:21, 17 September 2012 (UTC)
 * The TV show gets much higher viewer traffic than the Science. This much is verified. Its a fact. Your argument that the TV show hasn't aired in every country is not backed up with any facts.-- JOJ  <sup style="color:#CC9900;">Hutton  21:58, 16 September 2012 (UTC)
 * View traffic stats don't address the issue of long-term notability, which is a principle of the applicable policy. FWIW I'm not sure why you believe the traffic relevant here at all, as the title is the alternative name of the physical concept and is not the name of TV show. Period. — Dmitrij D. Czarkoff (talk•track) 22:28, 16 September 2012 (UTC)
 * The title is an obscure alternate name, not used in most of the sources and is a less likely search term than people looking for the television show. The article traffic shows that there is a higher probability in collateral damage if we continue using this current redirect.-- JOJ <sup style="color:#CC9900;">Hutton  03:04, 19 September 2012 (UTC)
 * I'm not sure of the basis for your judgment. I come across this alternative name more frequently then the primary name or any other. — Dmitrij D. Czarkoff (talk•track) 07:53, 19 September 2012 (UTC)
 * I'm not sure of the basis for your judgment. I come across this alternative name more frequently then the primary name or any other. — Dmitrij D. Czarkoff (talk•track) 07:53, 19 September 2012 (UTC)

 * Support redirecting to Atomic electron transition. If people search for the TV Show, they will use the Uppercase format. The Quantum leap already redirects to the Physics article, and I see no reason to not do the same here, unless you wish to do the same redirect to the TV show to that article too. In any case, there is a link to the TV show from the physics article anyways. TheOriginalSoni (talk) 14:57, 18 September 2012 (UTC)
 * There is no evidence that people will use the uppercase format when searching for the television show. If, on the odd chance that a person looking for the science, goes to the television show, link at the television show can also redirect people to the proper article. Given the lower article traffic at that page, the collateral damage will be much less in that fashion.-- JOJ  <sup style="color:#CC9900;">Hutton  03:04, 19 September 2012 (UTC)
 * You've repeatedly used the phrase 'collateral damage'. Personally, I don't think it's really damaging if TV show fans accidentally learn something about the physics concept that their TV show was named after, and then learn something from a hatnote about the proper capitalization of their TV show's title. —BarrelProof (talk) 05:13, 19 September 2012 (UTC)
 * Yeah, no harm done if people consider unrelated information as valuable as the information they're actually seeking. If those people exist, they're a very small minority. As are people who capitalize search terms, I'll bet. Personally, I use proper English online everywhere anyone can see it (even chatting), but never in search boxes. Check out Google Trends; none of the terms that would normally be capitalized in a sentence (peyton manning, doctor who, indy 500) are in search. InedibleHulk (talk) 05:43, 19 September 2012 (UTC)

Whatever is decided, all upper/lower case variants should redirect to the same thing. The red meat / Red Meat example is not exactly applicable here, since there are two articles with those exact names, but in this situation, there are no articles named "quantum leap" or "Quantum leap". The only article named QL is Quantum Leap, which is choice #2 above, so it would be best if all upper/lower case spellings redirect to Quantum Leap and let the disambig hatnote do its job. Most users nowadays don't bother with upper case when searching. Another approach is to shift to #1 and create a redirect page, but that is not best for readers. --Noleander (talk) 13:40, 19 September 2012 (UTC)
 * TV Show - The upper/lower case issue is not especially significant. The key issue here is how WP will disambiguate the phrase "Quantum leap" (any capitalization).  We have three primary choices:
 * 1) QL is a disambig page
 * 2) QL is the TV show
 * 3) QL is the atomic transition
 * It is exactly applicable here, since there is no reason not to apply it to redirects (since redirects are valid link targets and otherwise usable just like article titles, except for being the best title for the article). There are no articles named "quantum leap", so the current arrangement of hatnotes also do their jobs. And the current arrangement has the added benefit of serving to navigate readers who click on quantum leap wikilinks, all of which intended the transition. -- JHunterJ (talk) 18:43, 19 September 2012 (UTC)
 * TV show per page views and for screen reader users. I've been [//en.wikipedia.org/w/index.php?title=User_talk:Graham87&diff=513542852&oldid=513484849 asked to comment on this issue from the latter perspective]. All speech systems for blind people *never* read out capital letters when reading text by default, only when moving character by character. As a result, many blind people, especially young people blind from birth, are blissfully un aware of capitalisation conventions (even *I* didn't realise that "Wikipedia" was meant to be capitalised until I'd been editing the site for about a year)! Here's a fascinating New York Times article about this topic. Graham 87 15:25, 19 September 2012 (UTC)
 * I think this WP:ACCESSIBILITY argument is pretty compelling. Again, the red meat / Red Meat analogy is not applicable to this situation because WP has only one article named QL  (whatever the caps). --Noleander (talk) 16:36, 19 September 2012 (UTC)
 * As above, the analogy is applicable since WP has two articles on two topics that could be named QL (whatever the caps), one of which happens to have an even better name. -- JHunterJ (talk) 18:43, 19 September 2012 (UTC)
 * The fact is that it is "not" titled that. The current redirect is a disservice to the needs and viewing patterns of the readers who have already determined, though the article traffic, that the television show is the primary topic for the actual name of the television show. JOJ  <sup style="color:#CC9900;">Hutton  15:34, 22 September 2012 (UTC)
 * The fact is the current redirect is not a disservice to the readers. I agree the television show is the primary topic for the actual name of the television show, but the actual name of the television show is "Quantum Leap", and the title "Quantum Leap" has the television show as its primary topic. Leaving the redirect quantum leap allows readers who are looking for "quantum leap" to find it, allows reader clicking through wikilinks to quantum leap to reach the right page (since those are never used for the TV show), and does not place too heavy a burden on the readers seeking the TV show who type in the search term in lowercase in the search box but don't select the topmost suggestion in the dropdown but instead hit enter and have to click through the hatnote. -- JHunterJ (talk) 16:01, 22 September 2012 (UTC)
 * TV show. I've always found distinguishing titles based solely on initial capitalization (distinct from all-cap acronyms) to be confusing. Simply because Red meat and Red Meat exist does not mean that is a good model to follow in all cases. I'd favor deprecating that example in WP:AT, but that may be a discussion for another time. In this case, the scientific theory is not very commonly referred to as "quantum leap" and should not be considered as the primary topic for the lower case term. A hatnote on the TV show should suffice for those looking for the scientific concept. older ≠ wiser 16:55, 22 September 2012 (UTC)
 * So WP:PRECISION should be updated, since it gives that as a model to follow? The scientific theory is the only topic for the lowercase title, so should not be considered as anything other than the primary topic for the lowercase term. Hatnotes on both already suffice for those looking for the other. -- JHunterJ (talk) 16:59, 22 September 2012 (UTC)
 * You can't insist that the the scientific theory is the only topic for the lowercase title. Quantum leap is the obvious primary topic of Quantum Leap the TV show because not only is it the exact wording, but the TV show has the larger article views and therefore will be the most likely topic in any search.-- JOJ <sup style="color:#CC9900;">Hutton  17:58, 22 September 2012 (UTC)
 * I'm not insisting on it; I'm recognizing it. Under what scheme could the article on the TV show be titled "quantum leap"? (You've got the sentence reversed there, BTW. TV shows don't have primary topics; titles do.) -- JHunterJ (talk) 18:40, 22 September 2012 (UTC)
 * The scientific theory is the only topic for the lowercase title -- that is precisely the point of this RFC I think. I happen to disagree that the scientific concept it the only topic for the lower case title. Most of the time I do not bother to capitalize when searching (as most modern search engines present results from all cases together). I'll go out on a limb and assume that I'm not unique in that respect (i.e., searching using all lower case). older ≠ wiser 18:46, 22 September 2012 (UTC)
 * I believe you've missed the point. There is only one subject on Wikipedia that is called "quantum leap" – the physical concept. Coincidentally the technical limitations of search make some people lend at that name when they are searching for something which is not called "quantum leap" – "Quantum Leap" tv show. Thus the main question of this RfC is whether technical limitation workaround should prevail over common (the only so far) title. — Dmitrij D. Czarkoff (talk•track) 21:46, 22 September 2012 (UTC)
 * Well, no, not at all. 1) while I'm sure there are some sources that do refer to the physics concept as "quantum leap" that is neither the common nor standard name for the concept. 2) One of the three important aspects of disambiguation on Wikipedia is Ensuring that a reader who searches for a topic using a particular term can get to the information on that topic quickly and easily. I have seen no evidence and very much doubt that most of the page traffic for "quantum leap" is for the physics concept. Of the available topics, I think the TV show is by far the most likely target for the phrase, regardless of capitalization. 3) To be perfectly honest, I think even the metaphorical sense, for which I do not think there is an article, is a more likely target for the term than the specific physical concept. older ≠ wiser 22:02, 22 September 2012 (UTC)
 * (EC) Its not the only subject. You can say it a million times and you will be a million times wrong. The television show is called Quantum Leap, whether or not someone types the name in with or without uppercase letters, shouldn't detract from the fact that this is the title of the article, word for word. The science article is not called this. This has been a major disruption to Wikipedia ever since it was redirected to the obscure and rarely used article.-- JOJ <sup style="color:#CC9900;">Hutton  22:05, 22 September 2012 (UTC)
 * You can say Wikipedia article titles are case insensitive a million times, and you will be a million times wrong. The questions of what title to give a topic and what topic to give a title are parallel but distinct. -- JHunterJ (talk) 22:33, 22 September 2012 (UTC)
 * Nope not wrong, but thanks for the dramatics. People noticed. The science topic is called Atomic electron transition, not Quantum leap. Anyone looking for AET is less likely to type in "Quantum leap", while there is a much higher probability that anyone looking for Quantum Leap will type in "quantum leap". Its just a statistical fact that you haven't grasped yet. 20:1 more likely to happen according to the current article traffic stats.-- JOJ <sup style="color:#CC9900;">Hutton  22:42, 22 September 2012 (UTC)
 * Well, it doesn't even seem funny ever more. Obviously titles are case-sensitive on Wikipedia; otherwise Quantum Leap and quantum leap were the same page. Though facilitating search is a good cause, I see nowhere on Wikipedia any mention that addressing technical limitations should prevail over primary topics, so the whole case-insensitive drama still needs some policy or guideline to be based on. — Dmitrij D. Czarkoff (talk•track) 22:51, 22 September 2012 (UTC)
 * First I don't ever remembering typing that articles were not case sensitive. Don't know where that's coming from. Its the fact that people typing don't care that they are case sensitive and will be more likely to actually type in "quantum leap" than to type it in with uppercase. Article traffic views already prove beyond a shadow of a doubt, that the television show is the more popular of the two articles. People typing in "quantum leap" will be redirected to an article in which they were not looking for. Thats called collateral damage. Nothing is worse tan to be taken to an article you were not looking for. Quantum Leap gets well near or over 50,000 views a month, while Atomic electron transition is averaging around 2,000 a month. Its a no-brainer which article is the most likely search term, especially given that the article and the redirect share the exact same name. Its called WP:PRIMARYTOPIC. Its doesn't get more primary than the exact same name.-- JOJ <sup style="color:#CC9900;">Hutton  23:01, 22 September 2012 (UTC)
 * (EC) There is to my knowledge ZERO evidence that the physics concept is the primary topic for the lower case. Without any actual evidence, there is simply no basis for making search less useful, simply because it is possible to make lower case and upper case different titles. older ≠ wiser 23:03, 22 September 2012 (UTC)
 * Very good argument. Now that we have a majority on the RFC, the title should be redirected to Quantum Leap, until such time as a new consensus is formed, or the RFC is closed.-- JOJ <sup style="color:#CC9900;">Hutton  23:07, 22 September 2012 (UTC)
 * There is ZERO evidence that there is more than one topic for the lower case. Without any actual evidence, there is simply no basis for making Wikipedia less useful by leading readers from Wikilinks to quantum leap to an article other than the one intended. Happily, it is possible to make lower case and upper case different titles, so nothing needs to be made less useful. And, Jojhutton, RFCs aren't polls, and no new consensus has been formed in this one. -- JHunterJ (talk) 23:49, 22 September 2012 (UTC)
 * Here is the evidence Quantum leap is the actual name of the television show, with or without uppercase. Say it, it sounds the same. I don't know what you are playing at anymore, but it looks like a stall tactic. If there is a problem with the wikilinks, that is easily rectified. And you need to accpet the consnsus of the RFC, you don't get to decide, but somehow I knew you would say that. But define consensus in this case, if you will. What will it take before you accept the findings of the RFC?-- JOJ <sup style="color:#CC9900;">Hutton  23:56, 22 September 2012 (UTC)
 * I haven't decided the RfC. You also don't get to decide it. You do get to assume good faith, however. Say "Red Meat" and "red meat", they sound the same too. I have no doubt that this RFC will need a formal close by an uninvolved party, since neither of the competing rationales is sufficient to sway the holders of the other. -- JHunterJ (talk) 12:21, 23 September 2012 (UTC)
 * You keep using that same "Red Meat" example and its not the same because each of those articles is a stand alone article whereas two articles in question here are completely different sounding. The redirect should go to the article that is most similar in name.-- JOJ <sup style="color:#CC9900;">Hutton  13:19, 23 September 2012 (UTC)
 * The dramatics are yours, so the credit for them is yours as well. If you'll drop the misplaced rhetoric, I won't turn it around. -- JHunterJ (talk) 23:49, 22 September 2012 (UTC)

There is a technical aspect not considered so far: if you type 'quantum leap' in the searchbox, you are presented a list of suggestions, currently Quantum Leap, Quantum leap and a number of individual Quantum Leap seasons. I think the best solution would be if the top suggestions were Quantum leap (physics), Quantum Leap (TV series) and Quantum Leap (metaphor), in any order and any capitalization. That way every reader would be aware of the different meanings and could easily pick the one they're looking for, without anybody landing on the 'wrong' page, not even on a disambiguation page. I'm not sure if and how that's possible to achieve though.

Currently Atomic electron transition is a rather low quality stub, and the physical concept is not limited to transitions of electrons in atoms. Renaming to Quantum leap (physics) and maybe incorporating some material from Quantensprung could help. The metaphor is only mentioned in a single sentence in the physics article. For now it might be enough to expand that a bit and then redirect Quantum Leap (metaphor) to that section.

Regarding the original RFC question, I don't have a strong opinion. I lean slightly towards TV show, but see a possible conflict between the usage and long-term significance criteria of WP:PTOPIC. —  H HHIPPO  12:04, 23 September 2012 (UTC)

No new discussion for changing the existing consensus
See also: Talk:Quantum leap (disambiguation), Quantum leap (disambiguation) (which you're invalidating with this undiscussed change), Talk:Quantum Leap, and the above RfC. Please open a new RfC if you think all of that has changed. -- JHunterJ (talk) 12:35, 14 February 2015 (UTC)
 * Why don't you count again. The existing consensus is and has always been to redirect to the TV show. The new editors whom you are edit warring against only confirm this as well.-- JOJ <sup style="color:#CC9900;">Hutton  13:08, 14 February 2015 (UTC)

Move discussion in progress
There is a move discussion in progress on Talk:Quantum Leap which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 23:47, 22 February 2024 (UTC)

title: Talk:Quantum Leap


text:
S-expression

In computer programming, an S-expression (or symbolic expression, abbreviated as sexpr or sexp) is an expression in a like-named notation for nested list (tree-structured) data. S-expressions were invented for and popularized by the programming language Lisp, which uses them for source code as well as data.

Characteristics
In the usual parenthesized syntax of Lisp, an S-expression is classically defined as

 * 1) an atom of the form , or
 * 2) an expression of the form   where x and y are S-expressions.

This definition reflects LISP's representation of a list as a series of "cells", each one an ordered pair. In plain lists, y points to the next cell (if any), thus forming a list. The recursive clause of the definition means that both this representation and the S-expression notation can represent any binary tree. However, the representation can in principle allow circular references, in which case the structure is not a tree at all, but a cyclic graph, and cannot be represented in classical S-expression notation unless a convention for cross-reference is provided (analogous to SQL foreign keys, SGML/XML IDREFs, etc.). Modern Lisp dialects such as Common Lisp and Scheme provide such syntax via datum labels, with which objects can be marked, which can then recur elsewhere, indicating shared rather than duplicated structure, enabling the reader or printer to detect and thus trigger evaluation or display of cycles without infinitely recursing

The definition of an atom varies per context; in the original definition by John McCarthy, it was assumed that there existed "an infinite set of distinguishable atomic symbols" represented as "strings of capital Latin letters and digits with single embedded blanks" (a subset of character string and numeric literals).

Most modern sexpr notations allow more general quoted strings (for example including punctuation or full Unicode), and use an abbreviated notation to represent lists with more than 2 members, so that

stands for

is the special end-of-list object (alternatively written, which is the only representation in Scheme ).

In the Lisp family of programming languages, S-expressions are used to represent both source code and data. Other uses of S-expressions are in Lisp-derived languages such as DSSSL, and as mark-up in communication protocols like IMAP and John McCarthy's CBCL. It's also used as text representation of WebAssembly. The details of the syntax and supported data types vary in the different languages, but the most common feature among these languages is the use of S-expressions and prefix notation.

Datatypes and syntax
There are many variants of the S-expression format, supporting a variety of different syntaxes for different datatypes. The most widely supported are:
 * Lists and pairs:
 * Symbols:
 * Strings:
 * Integers:
 * Floating-point numbers:

The character  is often used to prefix extensions to the syntax, e.g.   for hexadecimal integers, or   for characters.

Use in Lisp
When representing source code in Lisp, the first element of an S-expression is commonly an operator or function name and any remaining elements are treated as arguments. This is called "prefix notation" or "Polish notation". As an example, the Boolean expression written  in C, is represented as   in Lisp's s-expr-based prefix notation.

As noted above, the precise definition of "atom" varies across LISP-like languages. A quoted string can typically contain anything but a quote, while an unquoted identifier atom can typically contain anything but quotes, whitespace characters, parentheses, brackets, braces, backslashes, and semicolons. In either case, a prohibited character can typically be included by escaping it with a preceding backslash. Unicode support varies.

The recursive case of the s-expr definition is traditionally implemented using cons cells.

S-expressions were originally intended only for data to be manipulated by M-expressions, but the first implementation of Lisp was an interpreter of S-expression encodings of M-expressions, and Lisp programmers soon became accustomed to using S-expressions for both code and data. This means that Lisp is homoiconic; that is, the primary representation of programs is also a data structure in a primitive type of the language itself.

Nested lists can be written as S-expressions:  is a two-element S-expression whose elements are also two-element S-expressions. The whitespace-separated notation used in Lisp (and this article) is typical. Line breaks (newline characters) usually qualify as separators. This is a simple context-free grammar for a tiny subset of English written as an S-expression (Gazdar/Melish, Natural Language Processing in Lisp), where S=sentence, NP=Noun Phrase, VP=Verb Phrase, V=Verb:

Program code can be written in S-expressions, usually using prefix notation. Example in Common Lisp:

S-expressions can be read in Lisp using the function READ. READ reads the textual representation of an S-expression and returns Lisp data. The function PRINT can be used to output an S-expression. The output then can be read with the function READ, when all printed data objects have a readable representation. Lisp has readable representations for numbers, strings, symbols, lists and many other data types. Program code can be formatted as pretty printed S-expressions using the function PPRINT (note: with two Ps, short for pretty-print).

Lisp programs are valid S-expressions, but not all S-expressions are valid Lisp programs. is a valid S-expression, but not a valid Lisp program, since Lisp uses prefix notation and a floating point number (here 1.0) is not valid as an operation (the first element of the expression).

An S-expression preceded by a single quotation mark, as in, is syntactic sugar for a quoted S-expression, in this case.

Parsing
S-expressions are often compared to XML: one key difference is that S-expressions have just one form of containment, the dotted pair, while XML tags can contain simple attributes, other tags, or CDATA, each using different syntax. Another is that S-expressions do not define a reference mechanism, where XML provides a notion of unique identifiers and references to them. For simple use cases, S-expressions are simpler than XML, but for more advanced use cases, XML has a query language so called XPath, many tools and third party libraries to simplify the handling of XML data.

Standardization
Standards for some Lisp-derived programming languages include a specification for their S-expression syntax. These include Common Lisp (ANSI standard document ANSI INCITS 226-1994 (R2004)), Scheme (R5RS and R6RS ), and ISLISP.

In May 1997, Ron Rivest submitted an Internet Draft to be considered for publication as an RFC. The draft defined a syntax based on Lisp S-expressions but intended for general-purpose data storage and exchange (similar to XML) rather than specifically for programming. It was never approved as an RFC, but it has since been cited and used by other RFCs (e.g. RFC 2693) and several other publications. It was originally intended for use in SPKI.

Rivest's format defines an S-expression as being either an octet-string (a series of bytes) or a finite list of other S-expressions. It describes three interchange formats for expressing this structure. One is the "advanced transport", which is very flexible in terms of formatting, and is syntactically similar to Lisp-style expressions, but they are not identical. The advanced transport, for example, allows octet-strings to be represented verbatim (the string's length followed by a colon and the entire raw string), a quoted form allowing escape characters, hexadecimal, Base64, or placed directly as a "token" if it meets certain conditions. (Rivest's tokens differ from Lisp tokens in that the former are just for convenience and aesthetics, and treated exactly like other strings, while the latter have specific syntactical meaning.)

Rivest's draft defines a canonical representation "for digital signature purposes". It's intended to be compact, easier to parse, and unique for any abstract S-expression. It only allows verbatim strings, and prohibits whitespace as formatting outside strings. Finally there is the "basic transport representation", which is either the canonical form or the same encoded as Base64 and surrounded by braces, the latter intended to safely transport a canonically encoded S-expression in a system which might change spacing (e.g. an email system which has 80-character-wide lines and wraps anything longer than that).

This format has not been widely adapted for use outside of SPKI (some of the users being GnuPG, libgcrypt, Nettle, and GNU lsh). Rivest's S-expressions web page provides C source code for a parser and generator (available under the MIT license), which could be adapted and embedded into other programs. In addition, there are no restrictions on independently implementing the format.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: S-expression


text:
Callitrichales

Callitrichales is a proposed order of flowering plants. As circumscribed by American botanist Arthur Cronquist in the Cronquist system (1981), the order included three families: A feature is the single stamen in the flower.
 * Hippuridaceae
 * Callitrichaceae
 * Hydrostachyaceae

The order is not recognized by the Angiosperm Phylogeny Group; the family Hydrostachyaceae is placed in the order Cornales and the plants making up the other two families are included in the family Plantaginaceae.

title: Callitrichales


text:
Talk:Gravitational singularity

Suggestion for clarity in one sentence of the very first section; that section is not editable (for me, anyway)
This really is a small enough thing, and does not touch on the science, nor do I propose any change of meaning. I suggest changing the following sentence's structure, just to make it a little bit clearer and readily understandable to the average (or maybe a bit below average) reader: "'Gravitational singularities are mainly considered in the context of general relativity, where density apparently becomes infinite at the center of a black hole, and within astrophysics and cosmology as the earliest state of the universe during the Big Bang.'" This sentence is fine, really, and correct, but I believe that the following edit makes the full meaning more clear for even more readers: "'Gravitational singularities are mainly considered in the context of general relativity, where density apparently becomes infinite at the center of a black hole; and within astrophysics and cosmology, gravitational singularities are considered as the earliest state of the universe during the Big Bang.'"

If the person(s) with the proper authority and permissions agree, then please do make the change. I offer this as a helpful suggestion, but I myself will not likely be back to the page at any predictable point in time and won't be monitoring any discussion that might take place. I don't expect it to be controversial, unless I myself have misunderstood what the original sentence means. Of course, if the sentence is subject to basic misunderstanding, that probably indicates a need for *some* edit, anyway. *smile* I'm glad I could help, in either case. 134.48.167.232 (talk) 07:43, 25 October 2020 (UTC)

Energy-mass limit in given finite space
Need a little more clarification for laymen: there's a bound for the amount of information in a finite region of space (Bekenstein bound, which depends on the amount of energy-mass in that region. Does it mean if there's an infinite amount of energy in a region of space then there's an infinite amount of information? Should there be an upper bound for energy-mass if Pauli exclusion principle really holds true? Also, if that's the case then singularity is ruled out?Mastertek (talk) 14:52, 23 October 2011 (UTC)

Source
Gravity, by Thorne, Misner, and Wheeler

Naked Singularities
I read this article and it is rather good although it may aquire some cleaning up. However, I did not see any mention of Naked Singularities. Would that be in a different article, is there anything about naked singularities on Wikipedia, or should I add a section on naked singularities to this article? Cheers!--The Relentless Rogue 02:32, 7 December 2006 (UTC)

The section on naked singularities (regarding the numerical simulations of Shapiro and Teukolsky) is very misleading - it seems to imply there is numerical evidence for naked singularities. However, shortly after their results, Robert Wald and Vivek Iyer showed that their findings were misinterpreted - that there was nothing out of the ordinary in the simulations. The name of the Wald-Iyer article is "Trapped surfaces in Schwarzschild geometry and cosmic censorship", 1991 in Phys. Review D. I am in favor of removing the reference to the Shapiro-Teulolsky simulations. Jjauregui (talk) 18:51, 3 March 2008 (UTC)

Time Dilation
I have read through this article twice and there is no mention of time dilation or the ability to use a singularity - especially naked singularities - to harness energy. I think that this article needs to be completely rewritten by an expert. 194.80.112.40 10:31, 19 February 2007 (UTC)

 * Time dilation is irrelevant to the topic. The ability to extract energy from a black hole has to do with physics outside the event horizon, and has no connection with the question whether there is a singularity at the center of a black hole. — Preceding unsigned comment added by Cherlin (talk • contribs) 04:29, 6 September 2011 (UTC)

Difference
The article doesn't explain what distinguishes a gravitational singularity from a mathematical singularity in GR equations. I put "sometimes" but someone took it away.

Here's the diff: mathematical singularities don't *always* means gravitational singularities because they can be artifacts of the coordinate system used.

 * I think, that there is practically, no difference between mathematical and geometrical singularity(ies). In fact, the latter is a practical phenonmenon of theoretical former.. --Krishnavedala 05:40, May 22, 2005 (UTC)

 * It seems that someone has been messing with the source, and data was lost. As for me the word "Hello" is rathewr unrelated to gravitational singularity ;). Please fix it...

 * Regards, Adam Hepner (not yet registered wikipedian)

 * The Gravity book, referenced at the top of this discussion, explains the differences between coordinate singularities, such as the North and South Poles, and real singularities, at length.

Gravitational singularities and entanglement?
Is it posssible that a pair of gravitational singularities can be entangled in a similarly to how electrons can be entangled?

If they cannot be entangled then can you explain why this concept doesnt work as I am curious to develop this idea?

 * Delving on the occult there dude ... . ---Mpatel (talk) 14:05, August 21, 2005 (UTC)

 * 1. There are no gravitational singularities.
 * 2. Black holes are not particles. They have the mass of several suns in the space of a proton at most.

This article Desperately needs complete overhaul
Need to clearly distinguish between geometric and coordinate singularities.

Among latter (aka gravitational singularities, although terminology nonstandard), need to point out that in exact colliding wave solutions, typically you have fold singularities which are geometric (not coordinate artefacts) but are not curvature singularities either.

I think should merge out some material into a new article on Curvature singularity, which should introduce some standard classifications:

 * scalar versus nonscalar
 * strong versus weak
 * spacelike versus timelike versus null (doesn't apply to all curvature singularities)

Both article should link to appropriate examples illustrating these in the Category:Exact solutions in general relativity, which I need to populate myself.---00:04, 15 September 2005 (UTC)

 * From the first sentence too. You don't need matter, first of all -- vacuum solutions in GR have curvature singularities (eg the Kasner universe).  Secondly, beyond the fact that volume is not a relativistically invariant quantity, it doesn't need to go to zero in a singularity, for example in a Big rip.  Finally the curvature need not diverge either, as pointed out for the folds in wave collisions.

 * That said, I'm not sure what a better alternative would be. Maybe something along the lines of A gravitational singularity is a feature of a spacetime, so that the histories of obeserves that encounter it appear to end.?  Sounds bad even to me.  Any other suggestions? Wesino 15:43, 25 November 2006 (UTC)

Singularity existence
The article says "singularities can exist even if the curvature of space-time is finite everywhere.". Surely singularities do not exist by definition, since they have have no dimensions?

Singularities exists because they have a verifiable, predictable effect on the stuff that is included in reality. The effects of singularites have been observed many times. They may even have dimensions that are definable in another dimension than the three space and one time we are more familiar with in everyday observations..

 * You two are talking about completely different things. Coordinate singularities like the North Pole and the South Pole exist at points of finite curvature. The other kind, the point mass with infinite density in a region of infinite curvature, simply does not exist, and has not been observed. Nor have any such effects been observed. If we had observational evidence of singularities, physics would be completely different from what it is today.--Cherlin 10:17, 19 October 2006 (UTC)

First, The Schwarzchild solution that this discussion is based on is only valid in empty space. At some point you get to the matter even if it is squeezed to a point. There you cannot calculate curvatures invariants, etc., because you do not know what the solution is anymore, T!=0. Second, cannot extend TOV equation or any other equation of state-based solution because the equation of state is completely unknown at r=0 densities. Third, using T=0 anywhere near an event horizon is dubious because the extent of the matter is not known.Bscip (talk) 20:33, 28 April 2019 (UTC)

Intro
So, is this article about 'gravitational singularity' or 'spatial singularity' (as the intro puts it)? Ben Finn 11:54, 25 August 2006 (UTC)

 * People get confused (look around this discussion page), so we have to make the distinction.--Cherlin 10:17, 19 October 2006 (UTC)

Singularity exists or singularity existed?
If we have established that the singularity exists, have we established if it still exists or that it just existed? Any ideas on the arguements or counterarguements for this topic or where the arguements are at right now? (Simonapro 14:59, 29 August 2006 (UTC))

 * We haven't, because it doesn't. Suppose you could put three solar masses at a mathematical point. Then the uncertainty principle says that its momentum is infinite. At this point the whole thing explodes. Now you might think that this is impossible, because neither particles nor photons can escape from a black hole. But that assumes the constant gravitational field of an unmoving black hole. What we are talking about here is all of the particles escaping at the same time in a spherical shell, leaving nothing at the center. The gravitational force inside the shell is zero everywhere, by a theorem of Isaac Newton.--Cherlin 10:17, 19 October 2006 (UTC)

I did an overhaul
The answer to most of the questions above is "No". Black holes don't get entangled; they merge. There is no evidence of actual singularities in the cores of black holes or at the time of the Big Bang. The mathematical complications requested above shed no light on the physics, and I won't do them. I'll probably add some references, including one for a detailed discussion of coordinate singularities, when I get home and can get them off the shelf. [Sorry, I didn't] I look forward to the Exact Solutions page. If somebody wants to add stuff on the quantum foam catastrophe in early quantum gravity theories, I'll applaud. Cherlin 2006 August 30

 * Are you saying that the Big Bang is flawed? If so, how do you explain (1)The age of the Universe according to WMAP and (2)The second law of thermodynamics with regards to a static infinite universe. If you are saying the Big Bang is not flawed, what was before the bang? (Simonapro 19:42, 3 September 2006 (UTC))

 * Excellent questions. The Big Bang theory is apparently accurate after the presumed first $$10^{-44}$$ sec or so. I am saying that we know nothing about the earlier interval from our current understanding of physics. I don't believe that there was a singularity before that. There are several theories of how a small region of spacetime could inflate into a universe. One of them is called "false vacuum". In some versions, the false vacuum region would create new inflationary bubbles with great frequency. This is one of several theories predicting that there are a multitude of what we currently think of as "universes". Probably there should be a page on several of these issues.--Cherlin 10:17, 19 October 2006 (UTC)

Jumble
Hi there. Seems like this article's in a bit of a mess. First of all, although entitled gravitational singularity, it starts by describing singularities in physics in general (quite well too), before finally getting onto its title subject. The formatting then breaks down such that sections and subsections aren't properly identified and separated. Finally, it ramblingly concludes with poorly formatted "notes" and a reading recommendation. My suggestion would be to create a new article, Singularity (physics), for the material at the head of the current article, then to tidy up the remainder so that its formatting is consistent with Wikipedia standards. For an article that appears in a template bar on GR, it's really quite ugly at the moment. Cheers, --Plumbago 16:09, 29 September 2006 (UTC)

 * I put in the singularities in physics in general because I don't think you can make sense of this problem without a more general understanding of the ways physics has dealt with mathematical singularities in the past. We could certainly rearrange things.--Cherlin 10:17, 19 October 2006 (UTC)

I have to weigh in on Plumbago's side. I like the discussion of various crises in physics, but I think they belong in their own article. It's not made clear what features they share with gravitational singularities, and I would argue that in fact there are no essential similarities (beyond "something becomes infinite"). I don't want to offend anyone, but here are the issues I see with this first section --

The examples have more to do with infinities than they do with singularities. Olber's paradox, the ultraviolet catastrophe, and the electron self-energy issue all result from adding up an infinite number of contributions, resulting in infinity, in a sense similar to a infinite series that doesn't converge. In these examples, there's a quantity that you compute at any point in space (total light from stars, energy density in blackbody radiation, energy in electron field) and it's infinity, everywhere. This isn't at all the same as the singularity in a black hole, for example, which is localized.

The only example that comes close, I think, is the electron one. Here you get one singularity comes from the fact that the potential energy of the electron-nucleus system would be infinite when the electron radiates away all of its energy and ends up in the nucleus (with everything considered as a point). You also get an infinite radiated energy. But the fact that point charges have infinite potential energy when they're sitting on top of each other is just regular, 19th-century electromagnetism and has nothing to do with quantum mechanics. Also the connection with gravity isn't clear.

There are also a few factual errors in the paragraph -- for one, the Pauli exclusion principle doesn't have anything to do with preventing the inspiral of electrons. It's true that it's related to electrons and atoms, which are also discussed in the paragraph, but the reason you don't get electrons spiraling in rapidly is not because of Pauli blocking. Secondly, you can "confine an electron in the space of a nucleus," or in any other finite region; you just get higher energy states for the electron (see square well). Finally, electrons do spiral into the nucleus in a manner perfectly consistent with quantum mechanics -- see electron capture.

The goal of making analogies to help the reader understand a gravitational singularity is admirable. But as it is, the intro paragraph talks about other historical problems in physics, then moves on to discuss things that aren't singularities (like problems with coordinate patches), and then concludes with talking about experimental tests of string theory. At this point, the reader's information about a gravitational singularity is still limited to the one-sentence intro at the top of the page.

So how about breaking this bit out onto another page, as Plumbago suggests? Wesino 15:35, 25 November 2006 (UTC)

Huh?
I am not a physicist, so maybe this is a dumb question. But the section on "Interpretation refers to "the ball of mass of some quantity." What the heck is that?  A quantity of what?  What is a "ball of mass", some kind of round mass like a planet or a star? Mcswell (talk) 04:06, 20 June 2016 (UTC)

Belief
I am still reluctant to believe that singularities exist, because of the zero demision problem. I am a theorist, it is hard for me to swollow things I can't see or imagine. maybe someone could point me in the right direction.-MJH 20:39, 8 October 2006 (UTC) Other theorists have problems with zero dimentions. Someone typed that a black hole singularity is smaller than a proton. Even at this size I see a major traffic jam of matter trying to enter the singularity. Matter would spiral toward the sigularity, minutely slower than the speed of light; it would miss by a few nanometers and collide with other particles trying to enter the singlarity: Failing to collide it would do a sling shot manuver which would carry it back to event horizon where it would turn around for another unsuccessful try at entering the singularity. Ccpoodle (talk) 18:04, 5 May 2008 (UTC)
 * If the Universe was limited by what we can imagine or see, there wouldn't be a Universe at all.

 * The article argues that there are no singularities in physics, no matter what the math says.--Cherlin 10:17, 19 October 2006 (UTC)

 * The article says General Relativity shows both coordinate singularities in metrics, and absolute singularities wherever a point mass turns up in the equations, usually in considering the evolution of a Black Hole. Changing to a different metric disposes of coordinate singularities. Getting rid of the infinite density, infinite force of gravity, and infinite curvature of space around a point mass requires changes in known physics. (Simonapro 12:08, 24 October 2006 (UTC))

 * I agree with Ccpoodle, about the zero dimension problem. Or even if a singularity has zero volume, how can we calculate the density? Density is defined as Mass/Volume, and attempting to solve with a Volume of zero results in division by zero, which is undefined. Tolkien fan (talk) 14:53, 1 July 2008 (UTC)

 * I think much confusion is caused by a misuse of terms. Space is first an abstract concept; things take up space, there is space between points and around them. But when discussing topics in Relativity, people tend to use the word space to mean spaces that have been measured. In relativity we often say "space" contracts, which is not meaningful using the first definition. Instead we should say that the thing we were using to measure spaces with contracted. Similarly with time. Things take time to happen. We measure the time something takes against something else. That's how measurements work; they are comparisons. Something can slow down or speed up. Often we say "time" slowed down, which has to refer to the thing we were measuring with, as that is the only physical option. In general relativity we say gravity curves spacetime, meaning the thing we were using to measure spaces and times with has curved. This is like saying the thing we are using to measure spaces and times with has curved. So a gravitational singularity isn't when Euclidean/Newtonian space and the concept of time curves into a paradox, it is when the thing we are using to measure those spaces and times ceases to be useful for making those measurements.
 * I have added a short paragraph to the introduction hoping to clear up this subtle difference. In case it becomes necessary later, here is one place these definitions are discussed. — Preceding unsigned comment added by 74.179.164.249 (talk) 22:22, 9 April 2014 (UTC)

 * Please sign your talk page messages with four tildes ( ~ ). Thanks.
 * I have removed the paragraph per wp:UNSOURCED. - DVdm (talk) 13:16, 10 April 2014 (UTC)

Good to hear voices that don't run with the herd. I think a finite sized star larger than the Schwarzchild radius resides in a black hole. Containing light or ultra relativistic material is not that difficult, a 2 solar mass neutron star almost does it. A point singularity is a simplistic explanation to explain a black hole and an inflationary universe. Unfortunately many millions of dollars or prize money and awards have been given out based on a point singularity and it will be hard to open people's minds. There is an establishment that supports a point singularity. Phrases like "the golden age" of black hole theory indicate the situation.72.69.11.171 (talk) 14:36, 23 July 2014 (UTC)BG

There might be a way to measure if a singularity exists in a black hole. When matter falls into a black hole, wouldn’t infalling matter emit radiation or jets differently if the black hole contained a finite sized star instead of a point singularity? A black hole star of 3GM/(c^^2) radius should contain light, but not as effectively as a Schwarzchild radius star or point singularity. There could be formulas for the radiation ejected from a black hole based on internal star radius.72.69.11.171 (talk) 02:06, 28 July 2014 (UTC)BG

Scientists are aware that mathematical infinities are unlikely to represent reality. What maths describes as an infinitely small, infinitely dense point, is more likely to be "very very small" and "very very dense". Infinities however are a very useful mathematical tool, and as much as the general public hates to believe it, mathematical tools are very powerful things for exploring the world around us. So if a theory involves infinities, this is not a sign that the science behind it needs to be completely re-worked.178.15.151.163 (talk) 10:08, 4 February 2016 (UTC)

A question for the cosmologists
There's one thing I've never understood about black holes. It was explained to me years ago that as matter approaches the 'event horizon' (Schwartzschild radius or whatever you prefer to call it), time is distorted in the same manner that space is, and in fact for a particle exactly at the event horizon, time no longer passes as seen from this universe. There's a certain syncronicity to that explanation that makes me believe it's true. If so, then how does matter ever actually ENTER a black hole? It seems like it would take infinitely long for a particle to fall into a black hole, even as it continues being accelerated by the immense gravity (since of course space is distorted as well.) Even as the black hole is being formed, the density near the center would increase infinitely slowly, and I would think that no event horizon could ever actually form. The density would increase continuously, and would approach arbitrarily closely to the density necessary to form an event horizon, but never actually achieve or exceed that density. An observed black hole, then, would be nothing more than a collection of particles that are exceedingly close to, but not quite, dense enough to form a singularity. It truth there can be no event horizon in our universe for the simple reason that it would take literally infinitely long to form.

Crackpot enough of a theory? Middlenamefrank 21:37, 27 October 2006 (UTC)

 * I think the fact that Zeno's paradox seems to be superceded by some force in the universe of motion would apply here too, and it would form regardless for the same reason that Zeno's paradox does not restrict movement, it would not restrict time here either. 66.243.213.232 (talk) 22:08, 4 September 2011 (UTC)

Maybe but from another point of view how about this: A Black Hole consists of whatever material produces gravity (call it matter if you like) which has managed to exclude through the effect of gravity both energy and space (or distance when you break down the speed of light as a distance traveled over time). A Black Hole is then from this perspective the composite manfestation of absolutes, i.e., absolute temperature (zero) absolute energy (also zero owing to absolute zero temperature requiring absolute zero energy) and absolute time meaning that when you cross the event horizon you are no longer traveling - you are already there - all points within the event horizon are reached simultaneously when time within the event horizon is infinite and distance zero. Adaptron 12:31, 3 November 2006 (UTC)

I think it works like this. From the outside observer it appears to never enter. Its not time that slows, its the speed of the light moving away from the black hole. The photons at the very edge of the event horizon leave the object with a very slow speed and, therefore, take a long time to reach the observer. The object that enters the event horizon notices no difference in the flow of time. So, to an outside observer the object appears to be moving slower and slower as it approaches the black hole. (and I would imagine would be red-shifted because of a longer wavelength, eventually leaving the visual light spectrum and actually becoming invisible to the human eye) 66.142.246.134 23:21, 4 January 2007 (UTC)

Myself, I have wandered through the same problem, but MORE importantly than the question of Event Horizon, the question should be maintained to the actual singularity: There does not exist a single singularity in the current time in our universe because the particles which are in their way to form the singularities of any given black hole are accelerating to infinite through time. For an outside observer, if he "could" watch the black hole through the event horizon, he would see an "almost" complete singularity, but not quite, and its particles would be seen almost stopped. To this outside observer, the moment the black hole would reach singularity would reside in an infinite point in time axis. To an inside viewer, though, if he could turn his "head" towards the outside of the hole, he would see a decreasing viewing disk of incoming matter and light, and he would see, in a finite span of time, the whole time span of the universe till the infinite reach his eyes as he reaches the singularity. He would have reached a point in the universe where space and time would be over, in a finite amount of time.

Have I written this clearly, or does it all sound BS? I really believe this should be the case. Anyone? 195.23.224.61 12:13, 23 February 2007 (UTC)

SG-1 Reference
"In the Stargate SG-1 episode 200, in a parody scene, it is mentioned that a singularity is about to explode. One of the characters even points out that this is impossible. This is used to great effect as a nod to scientific errors made in science fiction."

I thought Steven Hawking proved that singularities [i]could[/i] explode.

 * They don't explode, they (may) evaporate due to Hawking radiation - Fosnez 03:08, 24 July 2007 (UTC)

 * Depends on semantics. The end-phase evaporation of a singularity would be very rapid and emit alot of radiation. One could say that this is an explosion. 70.55.203.112 (talk) 10:01, 25 September 2008 (UTC)

Why is it impossible? —Preceding unsigned comment added by 81.178.39.81 (talk) 16:03, 7 September 2010 (UTC)

 * It is impossible because it would require whatever is inside to travel backwards through time, what we consider the radius as a direction through space in external coordinates becomes "the past" in internal coordinates. George Dishman (talk) 14:23, 24 February 2023 (UTC)

A better question is "Why is it possible?" 178.15.151.163 (talk) 10:04, 4 February 2016 (UTC)

Infinitely small vs. Planck scale
Assuming that the smallest physically meaningful unit of distance/space is the Planck length, or to put it another way, that the universe is composed of Planck-length time-space "units", what is the theoretical minimum density of a black hole mass compressed into this unit volume? Likewise, on the other end of the scale, what would be the density of the primordial Big Bang singularity, assuming current estimates of the mass of the observable universe? In other words, can we put numbers on the possible range of singularity densities, assuming that a singularity is not actually infinitely small? — Loadmaster 18:39, 2 October 2007 (UTC)

Who claims that a distance of the Planck-length is the smallest physically meaningful unit of space ? If energy is high enough you might be able to explore sub-Planck-scales, aren't you? Secondly I don't understand your reformulated question. minimum density of a black hole mass compressed into this unit volume ? There is an one-to-one mapping of the mass of a black hole to its volume (preciser to the volume encapsulated by its event horizon), if we neglect charge and angular momentum of a black hole. And of course you can easily compute the mass of a black hole whose event horizon has a radius of the Planck length. And the mass density of a black hole is strictly decreasing by a 3rd power on its mass (event horizon radius is a linear function of its mass).

Moreover I like to know whether my added section of "Uncertainty principle" should be renamed "Compton wavelength of a black hole" and should be better (or also) be put into the article considering black holes? Thanks in advance. —Preceding unsigned comment added by Achim1999 (talk • contribs) 16:14, 17 June 2009 (UTC)

space singularity versus time singularity
Would a gravitational singularity be the same as a spacial singularity (even just in certain terms)? I've also heard of the condition giving rise to the big bang construed as a "singularity in time" or a "time singularity" (though conceivably, and technically understood as, spacial as well I presume). Could there be an article on a "time singularity" as it would be theoretically understood? How would this relate to the quantum foam as the condition prior to the big bang? The quantum foam article does not delve into what I've observed to be speculated as the quantum foam state of the imminently-prior-to-big-bang condition. 66.243.213.232 (talk) 21:56, 4 September 2011 (UTC)

Did the universe start with a singularity?
The article states: "According to general relativity, the initial state of the universe, at the beginning of the Big Bang, was a singularity." However, I maintain that if people extrapolate backward in time far enough they reach not a singularity, but a point at which our knowledge of the laws of physics does not indicate what the previous state would be. Claiming that there must have been a singularity at the beginning or even that there must have been a beginning seems more like superstition than science. Who has ever seen such a singularity? I have called for a citation. - Fartherred (talk) 03:17, 3 October 2012 (UTC)
 * Compare the article to what NASA publishes here. "It [the Big Bang Model] postulates that 12 to 14 billion years ago, the portion of the universe we can see today was only a few millimeters across." That is just a theory, but one I respect.  The claim that the universe started with a singularity has no observational basis.  - Fartherred (talk) 03:37, 3 October 2012 (UTC)
 * Roger Penrose mentions "comprehensive theorems" that certain conditions are necessarily associated with a singularity under the mathematics of general relativity. The Big Bang is presumably one of them. This does not mean that the big bang started with a singularity in reality: these are conditions in which general relativity is known to be inaccurate (the quantum realm). But, aside from the lack of citation, the statement is presumably correct. — Quondum 14:44, 3 October 2012 (UTC)
 * Are you sure that a singularity is indicated by general relativity as a general case and not just a particular formulation that describes the big bang? As far as taking the trajectories of distant galaxies and extrapolating them backwards, we do not know the trajecctories well enough to be sure that they would meet in a point.  The universe might have net angular momentum and the extrapolation, if based on accurate enough information would reveal a rotating universe as the original maximum density state.
 * From what you write, it seems that the beginning from a singularity is a mathematical convenience that does not necessarily describe the universe. The big bang generation of protons and electrons from all energy is in theory accompanied by anti-protons and positrons, which we see in smaller numbers than would be indicated by theory.  General relativity and some descriptions called Big Bang might include a singularity in the mathematics but just mentioning that without indicating the apparent departures from reality seems to give a false impression of scientific knowledge about the early state of the universe.  Not long ago acceleration of the rate of expansion was first discovered.  If there could be a little acceleration, why not more, earlier.  It seems to me that this talk of a singularity at the start of the universe is taken much to seriously for the shaky ground it stands on.  - Fartherred (talk) 20:01, 4 October 2012 (UTC)
 * Well the singularity in the general relativity treatment of the Big Bang theory seems well enough known to not require a citation. It is referred to in the reference in Crux007's edit of 4 October.  Whether these theories describe the real world or not is something that could be discussed in the article if reliable sources are found discussing that.  I will remove the call for citation that I added.  - Fartherred (talk) 00:56, 5 October 2012 (UTC)
 * Yes, my impression is that the general conclusion is that general relativity itself is considered incomplete, rather than that there may be solutions to the unmodified general relativity that could escape singularities. I've just noticed the link to Penrose–Hawking singularity theorems. I see that article indicates that inflation complicates the picture. — Quondum 02:29, 5 October 2012 (UTC)
 * Thanks for the referral to Penrose–Hawking singularity theorems which in turn led to A Brief History of Time in which Stephen Hawking gives a negative evaluation of the likelihood of a singularity at the beginning of time. This seems like something which probably belongs in the article, but I have not even gotten the book yet to evaluate the meaning of the reference.  I will not be slighted if someone else puts a mention in the article before me.  I have too much to do anyway.  - Fartherred (talk) 02:22, 22 October 2012 (UTC)

"According to general relativity, the initial state of the universe, at the beginning of the Big Bang, was a singularity." Einstein didn't believe in a point singularity and he was presumably knowledgeable about general relativity. 72.69.11.171 (talk) 20:47, 23 July 2014 (UTC)BG

 * And your point is? —Quondum 22:35, 23 July 2014 (UTC)

 * If Einstein was alive should he be told to study general relativity more so that he would understand why there is a point singularity?72.69.11.171 (talk) 10:24, 25 July 2014 (UTC)BG

 * This is off-topic with regard to the editing of of the article. It is known that general relativity cannot be a complete theory of the physical universe (i.e. it must become inaccurate under certain conditions, including at singularities). That we don't have all the answers is no surprise. —Quondum 13:37, 25 July 2014 (UTC) Yes, general relativity is not accurate at singularities if singularities exist. 72.69.11.171 (talk) 17:47, 30 July 2014 (UTC)BG

A singularity would be obtained by extrapolating the scale factor during the radiation-dominated era back in time. The scale factor is proportional to the square root of time so goes to zero at some fiducial t=0. That extrapolation has been invalid since the hypothesis of an era known as inflation gained acceptance in the 1980s. During inflation, the scale factor depended exponentially on time so there is no longer a singularity in the current consensus model and this should be removed from the article. — Preceding unsigned comment added by GeorgeDishman (talk • contribs) 14:29, 24 February 2023 (UTC)

Arguements against a point singularity and infinite density
The contents of a black hole should be ultra relativistic. If the pressure P of ultra relativistic material is (rho)c2/3, the total thermal or viral energy of this star would be ∫PdV = (Mc2)/3, meaning a whopping 1/3 of the mass energy of the star would be used just to oppose the force of gravity. The star radius should be calculable using the viral equation. The best information I have is the gravitational potential energy of ultra relativistic material is very slightly higher than the Newtonian value, or about (1.1 GM2)/R. Using the viral equation (thermal energy equals half the gravitational potential energy) gives a star radius of about R = (1.65GM)/c2, or 0.82 times the Schwarzchild radius. A 0.82 Schwarzchild radius star would contain light. For this ultra-relativistic star both surface gravitational acceleration and core pressure decrease as size increases. It does not collapse.

Observational evidence of significant star radius in a black hole: Black holes have measurable spin. If a 5 solar mass object of 12 kilometers radius spins at 1000 revolutions per second, the equatorial velocity is a significant fraction of the speed of light. If a 5 solar mass object of 1 centimeter radius spins at 1000 revolutions per second, angular momentum is isn't conserved. 172.163.36.231 (talk) 00:34, 30 December 2012 (UTC) BG
 * Debating the physics behind (or the validity of) the subject matter of the article does not belong on this talk page. Do not expect to get a response to your argument here. — Quondum 08:20, 6 January 2013 (UTC)

Quondum- I am impressed with the articles on Gravitoelectromagnetism and Einstein field equations you were involved with. If a fraction of the effort on these subjects was applied on what happens inside a black hole a lot might be accomplished. The Tolman-Volkoff equations don't work for a black hole; they even give the wrong results for a neutron star. Maybe we could discuss this somewhere else. 172.162.18.21 (talk) 14:06, 9 January 2013 (UTC)BG

Inside a black hole and at the BIG Bang-Bit Bang, at their centers is a point singularity that reaches infinite density. Thus, the two are connected. 2601:580:10A:946E:6865:7117:AFC7:9D55 (talk) 21:51, 15 January 2019 (UTC)

not all mentioned here, German and US Universities teach alternative theories also
Please mention all views and enrich the article. By the way, there are no "singularities" in nature, but simply a "degenerate particle". Read what "degenerate matter" is, if "degenerate matter" gets more compressed, it simply becomes a quasi-fundamental indivisible particle. Due to the "holographic principle", the "black hole degenerate particle" is "ALMOST" (I said "almost" and it is hyper-extremely important so keep it in mind) a point, but never an actual one due to the "uncertainty principle" (no uncertainty = no existence). The "holographic chromodynamic data" always demand some "range of uncertainty" to be described, matter that enters faster than it can be absorbed by the black hole jets out at almost luminal (light-speed) speeds. — Preceding unsigned comment added by 2A02:587:410A:4200:7907:4615:761E:BA72 (talk) 17:00, 3 February 2016 (UTC)

If you are going to make claims like that, please include sources/references, otherwise all must assume it is just BS - this is the internet after all. You claim to know what is happening inside a black hole, a claim I have never heard any other scientist make. 178.15.151.163 (talk) 09:59, 4 February 2016 (UTC)

Extremely Distracting GIF Must Go
I have no idea if this is the right place for this comment, and I have no idea how to remove a GIF, but there is currently a GIF here so distracting it makes the article nearly impossible to read. Will someone please remove it? — Preceding unsigned comment added by Rickmoede (talk • contribs) 18:12, 8 August 2016 (UTC)

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Gravitational Singularity, Spacetime Singularity or simply Singularity
I changed the opening sentence to include simply singularity since this is how they are usually referred to... A gravitational singularity, spacetime singularity or simply singularity is a location in spacetime where the gravitational field of a celestial body becomes infinite in a way that does not depend on the coordinate system. 73.85.206.211 (talk) 20:55, 15 January 2019 (UTC)

Entropy
The section on black hole entropy confuses Hawking radiation with black hole entropy and black hole thermodynamics. It says the idea of black hole entropy was ignored before Hawking came up with Hawking radiation. This is false; Bekenstein, Hawking, and others had spent a lot of time thinking and writing about black hole thermodynamics and concluded that black holes had quantities that behaved like entropy and temperature, but it wasn't known if these were the same as entropy and temperature from "ordinary" thermodynamics. The idea that black holes had entropy was driven by the idea that if they didn't, they could be used to violate the second law of thermodynamics, and Hawking's thinking about black hole radiation was driven by that, not the other way around.

The best thing to do is probably to turn this section into a summary of the Black hole thermodynamics page and link to that as the main article. That article should probably also have its history section expanded a bit. I may do it when I have some more time and focus available. -Sean r lynch (talk) 23:38, 26 August 2019 (UTC)

This final sentence does not make sense to me. "This will occur at a cosmological redshift of more than one million, rather than the thousand or so since the background radiation formed". One Million what? Gooobster (talk) 21:27, 10 February 2022 (UTC)

Re: Singularities, the laws of physics break down
"Since such quantities become infinite within the singularity, the laws of normal spacetime break down." - 73.85.203.44 (talk) 14:15, 23 November 2019 (UTC)

Targeted comprehension level
What is the targeted educational level for proper comprehension of these and similar articles? G12, undergraduate, graduate? How does this effect accessibility, and how can it be enlarged? Oceanic84 (talk) 20:59, 11 February 2021 (UTC)

Typo in conical singularity section?
I'm far from an expert in this field, but I suspect the sentence

"A conical singularity occurs when there is a point where the limit of every diffeomorphism invariant quantity is finite, in which case spacetime is not smooth at the point of the limit itself. "

in the conical singularity section of the article is a typo. Surely at a non-singular point, the limit of every diffeomorphism-invariant quantity is finite, so why should this indicate the existence of a singularity?

I suspect the sentence should read something like

"A conical singularity occurs when there is a point where the limit of some diffeomorphism invariant quantity is infinite, in which case spacetime is not smooth at the point of the limit itself. "

Or possibly

"A conical singularity occurs when there is a point where the limit of some diffeomorphism invariant quantity does not exist, in which case spacetime is not smooth at that point.",

but I'd be more comfortable if someone who understands this better than I made the edit. Andylatto (talk) 17:03, 21 October 2021 (UTC)

 * It looks ok at it is. The metric can be finite everywhere the coordinate system is used, so all these limits exist and are finite. - DVdm (talk) 21:47, 10 February 2022 (UTC)

The problem of singularities has been solved.
The problem of singularities has been solved. See article, § 5. 178.120.19.87 (talk) 14:46, 16 April 2024 (UTC)

title: Talk:Gravitational singularity


text:
Calycerales

Calycerales is a historically recognized order of flowering plants. When accepted, it included the family Calyceraceae, which is now placed in the Asterales, with Calycerales treated as a synonym of Asterales.

title: Calycerales