Talk:Paul Ehrenfest

Inconsistencies
The Russian calendric biographical site http://www.znanie-sila.ru/online/issue_2337.html has a rather different biography of Ehrenfest on it. Even allowing for the old fashioned Soviet habits of distortion, I think it has much that should be taken into account when editing the Wikipedia entry on Ehrenfest, so here is my hasty translation:

Begin translation- 70 years ago 25 Sept. 1933, Paul Ehrenfest, Foreign Correspondent of the USSR Academy of Sciences killed himself. He was a great theoretical physicist of Austrian-Jewish extraction, professor of the University of Leiden (Holland), creator of an international school of theoretical physics. From 1907 to 1912 he lived in St. Petersburg (where he was called "Paul Sigismundovich"), and played a significant role in the founding and development of theoretical physics of European calibre in Russia. The cause for his arrival in Russia was his mariage to Tatyana Alexeevna Afanasyeva, who was studying mathematics at Goettingen University. Ehrenfests's suicide was caused by his loss of faith in his own abilities and his painful conviction of his own exhaustion of his scholarly potential. In addition to this, his strength of spirit was being continually undercut by his awareness of his younger son's incurable mental illness. And here was the tragic finale: Ehrenfest went to a country guest house, where his unfortunate son was being kept, sat together with him in a boat, rowed out to the center of the lake, where he first shot his son and then shot himself.

It is interesting that in the investigations following the NKVD arrest of the theoretical physicist Lev Landau in 1938, Ehrenfest was passed off as a German spy enlisting Soviet physicists.

End translation-

Now I don't expect that the Wikipedia article should take all of this at face value: but I do find it odd that it mentions his suicide, and not that it was a -murder-suicide. Nor does it mention the suspicious timing: suicide was NOT the normal cause of death in 1933 in Soviet Russia: the NKVD was. It is quite possible that even fear of the NKVD was a significant contributing factor to his suicide, esecially if they later accused him of being a spy.

I should also point out that then as now, being a member of the Academy of Sciences was reserved for scientists of the most outstanding calibre, even under Stalin and Khruschev. So it was a real honor to be named a Foreign Correspondent of the Academy.


 * But he was in the Netherlands when he died, not in Russia, in fact he had been in Leiden since 1912. I don't think the Russian article you quoted is controversial, it is more or less the same as what is found in the existing external link: http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Ehrenfest.html


 * -- Curps 03:48, 16 Jan 2005 (UTC)

and blinding?
128.135.224.3 made a revision on 01:49, 13 April 2005 saying

He suffered from low self-esteem and constant doubts about his abilities, and eventually committed suicide, shooting and blinding his son, who had Down's syndrome, before shooting himself.

Where does that and blinding come from? I cannot find any reference that confirns that. What I do find is that Ehrenfest's son Wassik was institutionalized in Amsterdam, and that he took Wassik from the institute to the Vondelpark in Amsterdam and then shot him there before killing himself. No reference to 'blinding' though. JdH 21:53, 3 February 2006 (UTC)


 * Should the mentioning of Wassiks Down's syndrome be mentioned? Reading the article, it seems pretty strange, that he seemingly picks a random child of his and kills it while having arranged for the other children. It's likely that the Down's was the reason why he chose Wassik.--Nwinther (talk) 08:14, 12 August 2010 (UTC)


 * It is abundantly clear that his mental illness is the underlying cause of this tragedy, and it is on only cause. It is a fallacy to believe that his son's Down's syndrome would one way or another provide an explanation for the tragedy: it doesn't. JdH (talk) 14:01, 9 February 2011 (UTC)
 * Previously, the article just said that Wassik was shot. The Downs could be an explanation as to why he chose to shoot Wassik (rather than see to his future care which he did for his other children). I don't see how it can be read as if I propose that Downs was the cause of the tragedy (murder-suicide).--Nwinther (talk) 11:04, 22 November 2011 (UTC)

-- The article makes it sound like euthanizing handicapped people is okay. It reads like "He shot his son, but it was okay because he was depressed, and his son had Down Syndrome." It's not okay to murder handicapped people. He's a murderer, and the fact that he killed himself, comes second. How tragic is the death of school shooter compared to the death of the students he killed? — Preceding unsigned comment added by 170.173.0.16 (talk) 00:20, 26 September 2014 (UTC)

too negative?

 * I think that too much of this article is devoted to the negative; clearly Ehrenfest suffered of major depression, which nowadays would be easily treated. But is not appropriate to emphasize that aspect too much. Ehrenfest was a great scientist, and this article should emphasize his scientific and scholary achievements instead. JdH 11:31 31 January 2006


 * I think that you should just contribute to this article what you know about him. If you think that it emphasizes too much on his depression, add more about the positives. That's how wiki works. BigBen212 17:10, 31 January 2006 (UTC)


 * A couple of days ago I made a major revision, and edited the existing negatives JdH 21:53, 3 February 2006 (UTC)

In view of all the inaccurate information that is out there about this issue I want to set the record straight. The following comes from the website of the Physics Department of the University of Amsterdam A.J. Kox Een kwikkolom in de Westertoren: De Amsterdamse natuurkunde in de jaren dertig (my translation):


 * On a personal level a really dramatic event took place at the Department. On Monday September 25, 1933 Paul Ehrenfest traveled from Leiden to the laboratory in Amsterdam to visit Rutgers, a former student of him. It was a farewell, but nobody was aware of that. In the afternoon Ehrenfest left the laboratory and went to the Vossiusstraat, where he picked up his mentally ill son from the institute where he was institutionalized. There nobody suspected anything either. Together the two went to the Vondelpark. There Ehrenfest first shot his son, and then committed suicide. The son lived for a few hours. The tragic event made a deep impression, especially on those who had seen Ehrenfest in the laboratory that day. On of them, Jan de Boer, student-assistant of Michels and later professor of theoretical physics in Amsterdam, can still remember well how at the end of the day Rutgers came very distraught to the laboratory to tell the news. The same day Rutgers went to Leiden to support the remaining children (Ehrenfest's Russian wife was on a visit to her home country). As he explained later in a letter to Zeeman, who was in Paris, Ehrenfest had asked him that implicitly: 'He asked me get ready, in order to travel to Leiden together and stay the night if necessary. That was to prepare for his children. (...) At about 3:30 PM he left by cab (...) At 5 PM it had happened. He did not suffer. (...) I went immediately to Leiden on Monday, stayed the night there, and returned Tuesday night. The children are coping reasonably well.'

Please do not post this on the main page; I strongly believe it does belong there. JdH 17:25, 9 February 2006 (UTC)

I don't even know how I landed on this page and I don't want to start or continue a revert war. But I see no legitimate reason to eliminate the information about the truly tragic end to Ehrenfest's life. I don't believe readers are so squeamish that they want obviously significant details hidden from them. The description is not graphic, gory, or overlong, just a brief statement of fact.Ande B. 21:58, 30 March 2006 (UTC)


 * The issue is: this is supposed to be an encyclopedia, not a tabloid. The tragic circumstances of Ehrenfest's death are clearly mentioned, and that should be quite enough for an encyclopedia. If you want to know more, just search the internet and loads of details will appear. JdH 22:28, 30 March 2006 (UTC)


 * Thanks for your quick response, Jdh. I despise tabloids, but in a previous existence, I spent enough time in journalism classes and small papers to believe I can distinguish between a tabloid account and a straightforward, biographical account.  I appreciate your sentiment but think you are mistaken here.  There is no lurid language, no graphic descirptions of gore or editorial psychoanalysis of Ehrenfest that is typical of tabloid copy.  I don't see why you insist that readers go elsewhere for basic information and I don't understand why you take it upon yourself to constantly revert any mention of it.  Take a look at Alan Turing's bio.  Would you prefer that Turing's homosexuality and disputed suicide be kept out of that article?  Sorry, but it looks to me that you simply refuse to accept alternate preferences and castigate those who disagree with you as being "tabloid" writers.  As a reader, I want it in the article and don't see why your preference should outweigh those of other contributors.  For the record, the only change I am supporting is the following sentence:
 * On September 25, 1933 he committed suicide under tragic circumstances, first shooting his institutionalized son Wassik, then himself.
 * It is the murder of his son that makes this episode exceptionally tragic. If you see this as being tabloid writing, I suggest you have set your sensibility filters way too high, mistaking your personal preferences as the sole standard of ethical editing.  Ande B. 23:58, 30 March 2006 (UTC)


 * Please take a look at the version of this article of 04:36, 26 January 2006 by Brennan Milligan; that was the text of this article as it was before I started to change it, and put in more detail about Ehrenfest's scholarly and scientific achievements. Also take a look at the McTutor biography of Ehrenfest. What was here on January 26th came almost exclusively from the McTutor biography, but for some strange reason people had only put in the negatives in any sort of detail, and never took the effort to give a detailed account of his scholarly and scientific achievements. Furthermore, the McTutor biography itself is very colored in the first place. For instance, they put in the private letters he wrote to his closest friends, written at the depth of his clinical depression, and present it as if it characterizes the man. What they completely fail to recognize is that Ehrenfest had a clinical depression; I am dismayed by the fact that people don't even understand that clinical depression is a disease, and that what people do and say during such an episode is caused by the disease, and as such does not belong in a biography. If somebody has some physical ailment, all what is and should be mentioned are the facts; you don't present the details of what is in that person's medical record. But for some reason psychiatric disorders are not treated that way; people seem to think that the details of that disease are fair game.
 * I actually think that in this respect there is quite a cultural difference between the Anglo/American world on one hand, and continental Europe on the other. Traditionally (but that may be changing) people from continental Europe respect other people's privacy. The Anglo/American world seems to think that people's private life is fair game. There is a sentence in the McTutor biography that highlights that cultural differnce quite clearly: "The Dutch papers only reported his sudden death and gave lengthy accounts of his achievements." I propose we follow that time-honored tradition. JdH 10:54, 31 March 2006 (UTC)


 * I think I am on Ande B's side on this. The most important part of an article on a scientist is the part on the scientific work (and looking thru the history page, JdH has improved the article a lot here). But a murder is notable enough to be in a bio, even if it was a result of a mental illness (which should be mentioned). I don't think an event like this goes as "unencyclopedic private life", as the consequences of it is too far reaching. There is no tradition in wikipedia to leave out negative/tradic event. Btw, did his son die? A previous edit suggest he was blinded. Zarniwoot 17:56, 31 March 2006 (UTC)

According to the description above from the Physics Department in Amsterdam his son died a few hours after the shooting incident. I cannot find any independent confirmation whatsoever about that "blinding" bit. It was at some point put in by an anonymous editor; I put a question on his talk page, to which he never responded. What is even more troubling is that that contribution to this article is the only contribution 128.135.224.3 ever made at all. My conclusion is that this is an example of vandalism that remained uncorrected for almost a year, and as a result it has propagated all over the internet.

For the record: That was how I found this acticle in the first place. I happened to come across that description on some copycat site, which led me to this wikipedia article. In the mean time it had spread to scores of other copycat sites that had copied it as well. JdH 08:47, 1 April 2006 (UTC)


 * JdH, I think your contributions have been substantial and demonstrate good research and writing skills. You turned a brief sketch into a good article.  I only disagree on this one small point.  And I don't think that the mere mention of the dreadful final events is "tabloid," nor do I think they are the result of Euro vs American notions of privacy.  The shooting of his son is a felony in any jurisdiction and that takes it out of the realm of "private" actions.  Ugly details about the shooting or contents from his personal letters that are used only to psychoanalysze him are, in my mind, inappropriate for this type of article.  But the article is a biographic one, not one devoted only to scholarly achievements, although those achievements are what make him notable in the first place.  It may be important to note his clinical depresion in the non-judgmental manner you have used; it certainly goes some way to explain his truly tragic end.  It also helps those who suffer from depression today to understand that anyone can be afflicted by this disease and the need for proper medical care.  As I said, I am looking at this article only from the point of view of appropriate coverage, nothing else. Wiki standards look for neutral point of view and accuracy, not personal preferences. Ande B 00:25, 1 April 2006 (UTC)

In the country where I come from those kind of details are never put in a biography. My description of those tragic events is based on Casimir's biography on Ehrenfest, who does not bring up those details either. I suggest that you help extend and improve the description of Ehrenfest's life and achievements before contributing to the description of his death. JdH 08:47, 1 April 2006 (UTC)


 * JdH, I'm just here trying to do something productive while I am too ill to work at the office.  I try to make contributions that are best served by my professional background and interests.  That does not include special expertise about Ehrenfest but it does include a long history of writing, editing and proof-reading and some understanding of US and international intellectual property laws.  That is largely why I limit the types of edits I make on subjects for which I don't have a deep understanding.  I'm not trying to be a royal pain about this little issue and it may well be that your culture has very different expectations for biographies than the Anglo-American culture.  I must say, though, I am surprised that any  biography would not include a straight-forward fact that is a matter of public record.  Still, you are writing this article for people all over the world.  And although you are the major contributor to this article, in the end, every page at Wikipedia is a joint effort.  It takes an abundance of tolerance and flexibility to work on a group writing project. You've certainly gone out of your way to fix an article that will be read primarily by people who don't share your native language.  Ande B 10:22, 1 April 2006 (UTC)


 * If a misunderstanding is present on the internet, so much more reason to bring the facts on wikipedia. Zarniwoot 14:30, 1 April 2006 (UTC)

I managed to come up with a compromise: I put in an internal link to the discussion here. I hope that this will provide information to those who are interested in it, without distracting from the real purpose of the article, which is to provide a description of Ehrenfest's life and achievements.

One of the references mentioned in Rowdy Boeyink's master's thesis is a presentation given by Frans van Lunteren, Paul Ehrenfest, de Leidse onderzoeksschool van een fysicus in diaspora (2003), which provides some more detail about Ehrenfest's mental problems. The first paragraph is as follows: ''At the end of August 1932 Philip Idenburg, secretary of the Board of the University of Leiden, received a disturbing letter. Author of the document was Albert Einstein, and the subject was the mental condition of professor Paul Ehrenfest. Einstein openly expressed his concern about Ehrenfest, who according to him was deeply depressed and was toying with the thought of suicide. Einstein urged them to take quick action''. One of the suggestions Einstein made was to reduce Ehrenfest's load by appointing a secondary professor in theoretical physics. Recent growth in the field had been such that it was no longer feasible for one person to cover all of it. The Board did pursue the possibility to do that, but unfortunately no money was allocated for it by the Department of Education in the Hague. JdH 14:25, 5 April 2006 (UTC)


 * JdH, you seem to have hit upon an unexpected solution. I'm grateful for your providing the information about Einstein's concern about Ehrenfest's condition.  Ande B 20:39, 5 April 2006 (UTC)


 * It's great to see an effort to reach a compromise. I'm concerned, though, that it violates some guideline to link to the talk page from the article. Perhaps Avoid self-references: "...and do not refer to any link in the sidebar or along the top of the screen, such as the talk page...". Who knows if this will be in the talk page next year?


 * I can absolutely follow JdH's reasonings on this. I am, for example, amazed how the private and public life of politicians are mixed in the USA and GB, and I agree that it would be unfortunate if some readers remembers Ehrenfest as "the guy who killed his son" instead of as a great scientist. But I think it is relevant, and should be in the article. If we could document that it properly happend as a consequence of a mental illness, it should put the event in the right perspective, I think.


 * I am thinking about requesting for comment at the History of Science WikiProject to get some more eyes on this and hear if there is a consensus on this kind of dilemma from other wikipedia biographies. Whatever the result of this discussion, it will be useful to have a broad consensus for future editors of the article. Zarniwoot 23:19, 5 April 2006 (UTC)


 * I am rather new to wiki editing but I have used numerous, often conflicting, style guides in the past. Any official direction is helpful.  I appreciate that everyone seems to be approaching things with a great deal more civility than on Usenet!  Ande B 23:50, 5 April 2006 (UTC)


 * Me too. I have actually seen people apologize too each other here!:-)... I'm quite new here too, but I think the main problems of linking to the talk page is that it can be archived, breaking the link, and that the link will not work in derivative works. Zarniwoot 02:23, 6 April 2006 (UTC)

Ehrenfest's death is a well-known aspect of his life, and colors any assessment of his personality and work. While excessive details are unnecessary in most cases, I see no reason that the tragic circumstances should not be discussed. They are not secretive and are in fact discussed in many historical works which discuss Ehrenfest, so it is not exactly the airing of any new dirty laundry. The link to a talk page for the discussion is not sufficient or proper -- article content and article discussion should be strictly segregated, they are two different things entirely. --Fastfission 23:57, 6 April 2006 (UTC)


 * Of course, if the information is in the article (which it currently is), there is no reason that applicable categories relating to suicide shouldn't be added. There may be an overarching argument as to why these categories should be completely deleted, but this generally isn't done on an article-individual basis, but through a global WP:CFD process. Until the categories for suicides, etc. are deleted, they may be applied here if they are factually supported by the text of the article. To do otherwise can appear to be a form of selective censoring, which WP does not do. Good Ol’factory (talk) 22:31, 9 October 2008 (UTC)

Twopennorth
I've come here from WikiProject History of Science and the first thing to say is HUGE CONGRATULATIONS to JdH and everyone who has turned this from a stub into such an excellent article. Very, very well done! The second thing is to declare my possible bias, which is that I've suffered from clinical depression. I completely agree with JdH about the imbalance in the stub; but now the article has been expanded, it would be possible (if one wished) to say more about his health without making it the main thrust of the article (which I think may be the tabloidism of which JdH complains). So for me, the question is, Did his health affect his life and work, which are the things this article covers? Just as Milton's blindness and Beethoven's deafness either impacted on their actual output, or demonstrate their enormous powers at being able to create amazing works without the usual aide-memoires, so Ehrenfest's achievements generate even greater respect when seen in the context of his life (in which health might be a factor, just as education and religion might be).


 * I am unable to assess how his mental problems affected his work, if it did at all. The sense you get that he was a highly gregarious person; he thrived by constant and intense interaction with other people. In that sense he was the complete opposite of the popular picture we have of theoretical physicists: somewhat withdrawn, laboring away in relative isolation. He travelled a lot, visited other scientists, invited them over to Leiden, had discussions with them, etc, He was so to speak at the nexus of a social network of scientists, and in that way he was a facilitator of the development of the new physics that happened during his lifetime. Casimir mentions that he was quite entertaining. None of that tracks with what you expect from a person who is depressed.


 * Actually, it doesn't surprise me at all from a depressive struggling against their condition. These paragraphs ring scarily true... But as you say below, we're not in the business of diagnosing him. JackyR 15:06, 7 April 2006 (UTC)


 * On the other hand, as a foreigner he was somewhat isolated in Leiden. The only person he had a close personal relationship with was Lorentz, and after Lorentz passed away in 1928 he became even more isolated. He interacted very intensely with his students; not just on science, but also in personal matters, overbearing even. I don't know what to make of all that; it seems to me that things started to go downhill after Lorentz' passing, but I can't make sense of it. Maybe it would be interesting to have a psychiatrist go over his letters; perhaps that would shed some light on it. JdH 02:54, 7 April 2006 (UTC)

Again, I agree with JdH that the MacTutor article labours the theme. But I also agree with Ande B. et al that it should be mentioned, and would myself explain (briefly and without adjectives) the circumstances of his death and his son's. Coyness, like "very tragic circumstances", to me suggests shame - and leaves one speculating on what was so bad it couldn't be said. I don't think depression is shameful, and I don't think the killing of his son was shameful (though it was tragic) so why can't we mention it? For comparison, if Ehrenfest had suffered a heart attack at the wheel of his car and his whole family had died in the crash, would we mention that? We might, even tho it would illustrate nothing about his life and works.

From the depressive's corner, I think that his letters and Einstein's comment (end of the MacTutor article) are a perfect illustration of the gulf between Ehrenfest's value of himself and others' value of him: a very major effect of the disease. So if left to me, I would include Einstein's comment as tribute, with a note about the contrast. Again, I absolutely wouldn't suggest this if the article were still very short. Just some thoughts - ignore if you like! (PS Continental Europe's respect for private lives? Have you seen Bild?!)JackyR 01:06, 7 April 2006 (UTC)


 * Thank you for your suggestion. Based on what you just said, and reading back what I just wrote myself in the previous paragraph I have come to the conclusion that it is improper for me to make the diagnosis clinical depression; only a psychiatrist is qualified to do that. I have changed it to mental illness; that seems more appropriate, and it appears to me that that internal link provides more relevant information as well. JdH 13:40, 7 April 2006 (UTC)


 * Yes of course. That's completely correct and I should have thought of it myself. But I would put it as "mental illness that may have been depression", to distinguish from senile dementia, schizophrenia, etc. This way we're not making a diagnosis, but offering the reader the same impression our own sources give. JackyR 15:06, 7 April 2006 (UTC)
 * Actually, no. On reflection we're creating a fallacy. We don't know that he "suffered mental illness" (unless he was diagnosed as such): this is a deduction from our belief that he was depressive, not a cause of that belief! All we can accurately say is that he appears, from his letters and behaviour, to have be suffering from depression at the time of his death, and that there is some evidence (quoted on the MacTutor site) that this may have been life-long.


 * I was actually thinking of bipolar disorder as a possible alternative diagnosis; what about "... depression or bipolar disorder"? JdH 15:52, 7 April 2006 (UTC)


 * This starts to get complicated :-) A few paragraphs back (14:25, 5 April 2006 (UTC)) I mentioned a letter from Einstein in which he expressed his concerns about Ehrenfest's depression. That's probably the best we have; Einstein was not a psychiatrist either, but he was a close friend. JdH 16:15, 7 April 2006 (UTC)
 * Agree. I'll do (another!) draft for the final section later today, unless you get there first!. By the way, serious Wiki-praise for the work you're putting in to get this Just Right! JackyR 16:34, 7 April 2006 (UTC)


 * Well, I guess not. I was thinking about putting in a sentence along this line: "In the summer of 1932 Einstein wrote a letter to the Board of the University, in which he expressed his concerns about Ehrenfest's depression". But I didn't like it: I think it is too heavy. Just think about it: If one of your closest friends is depressed would you write a letter like that to her boss? I know for a fact that I wouldn't; perhaps tell her to go see a psychiatrist, but that's it. What I did do is change the internal link to mood disorder; I thought that the information in that article is much more appropriate than what's in the clinical depression or mental illness articles.
 * On your suggestion I did add some quotes. I still want to make a few additions to clarify how influential he was on the development of the new physics. In particular get a list of people who spent some time in his lab; the ones I know about are Viktor Trkal, Enrico Fermi, Robert Oppenheimer, and Werner Heisenberg, but there must be more. And then there is of course Walter M. Elsasser, but as recounted inthis biography that didn't work out at all. JdH 15:11, 10 April 2006 (UTC)

Oh Very Rude Words. I've just accidently deleted several hours' work, fiddling around and referencing to try to get the paragraph OK. Sorry it was late in the first place: and now will be later still, as I'm not going to redo it tonight. Grrrrr! JackyR 00:09, 11 April 2006 (UTC)

Draft last §

 * ==Final years==
 * Ehrenfest was greatly respected by his students and fellow scientists, but [himself suffered] had severe doubts about his own abilities. In May 1931, he wrote to Bohr, "I have completely lost contact with theoretical physics. I cannot read anything any more and feel myself incompetent to have even the most modest grasp about what makes sense in the flood of articles and books."[ref] The [self-]doubts continued, and it seems likely he was suffering from clinical depression: there is evidence this may have been life-long [ref]. By August 1932, Einstein was so worried about that he wrote to the Board of the University of Leiden, expressing deep concern and suggesting ways in which Ehrenfest's workload could be reduced.[ref]


 * On September 25, 1933 Ehrenfest died in Amsterdam. Having made arrangements for the care of his other children, he shot dead his younger son, Wassik, who had Down's syndrome, and then himself.

The last part is very bald, but I can't think of a way to put it without expanding it. Everyone is welcome to fiddle with it, but please can we keep most of the information? Cheers, JackyR 16:49, 11 April 2006 (UTC)


 * I am not so sure about that "severe doubts...." stuff. The problem is that in his depression that was the way he felt about it, but his fellow scientists looked at it quite differently, even in those fateful final years. Any scientist has a struggle to keep up with the latest developments in his field, certainly in a rapidly developing field as theoretical physics was at the time. To some extent he was in the same league as his friend Einstein: Both of them hated the strict mathematical approach of the new quantum mechanics; the lack of simple models to illustrate and clarify the underlying assumptions. So what would a normal person do? Focus on the things you are good at, and find some way to have somebody else teach the courses you are not comfortable with. In short: turn it into a management issue rather than one of competence. Nowadays there are separate courses for classical mechanics, electro magnetism, statistical mechanics, and quantum mechanics; those 4 courses are typically taught by 4 different people. But Ehrenfest tried to do all of that all by himself! So how come he felt "incompetent"? The point being: It only illustrates that he was depressed, not that he actually was incompetent.
 * Let me think about it for a bit; I will try to come up with an amended version. JdH 19:04, 11 April 2006 (UTC)


 * Um, but we're not saying PE's doubts were justified - simply that he had them. I've made that stronger - but of course you may come up with something better. In fact, in the current version we don't comment on his maths ability at all, for the good reason that none of the materials comment on this specifically: the positive quotes were all about his teaching. JackyR 21:05, 11 April 2006 (UTC)


 * About the maths ability: It may be very instructive to look at an article his wife Tatyana wrote about teaching basic courses in math to highschool students, see Exercises in Experimental Geometry. 1931. She, like her husband, was committed to explaining the basics of math using simple models or visual aids. Casimir mentions that his famous clarity in teaching should not be confused with mathematical rigor: it wasn't there. But about his math ability'' as such I couldn't comment; I think it has more to do with the notion that it is essential to first illustrate and explain the basic assumptions, 'gut feeling' if you like, before you can go ahead with complicated mathematical derivations. I have put in a quote from a letter to Oppenheimer to illustrate that; I may strengthen the point. And I can very well imagine that with Heisenberg's matrix mechanics, and especially with the Dirac equation you hit a brick wall. JdH 21:47, 11 April 2006 (UTC)


 * Next iteration final draft:
 * From the correspondence with his close friends of May 1931 it appears that Ehrenfest suffered from severe depression. By August 1932, Einstein was so worried that he wrote to the Board of the University of Leiden, expressing deep concern and suggesting ways in which Ehrenfest's workload could be reduced. (Frans van Lunteren, Paul Ehrenfest: de Leidse onderzoekschool van een fysicus in diaspora (2003))
 * On September 25, 1933, he sadly lost his battle with depression. Having made arrangements for the care of his other children, he first shot his younger son Wassik, who had Down's syndrome, then killed himself.


 * Essentially, what I am trying to do is stop this blame-game that has been going on for such a long time. Point out that het suffered from a serious illness, and that in the end he succumbed to it. JdH 15:06, 12 April 2006 (UTC)


 * Beautifully done! Very elegant, verifiable, and complete. Gold star for that man! JackyR 17:51, 12 April 2006 (UTC)


 * Excellent! Zarniwoot 16:12, 17 April 2006 (UTC)


 * Let me repeat JackyR and say "elegant."  Sensitively done, too.  Thank you for putting so much effort into this.  Depression is a serious illness. I think you have treated it with great insight.  Ande B 19:36, 17 April 2006 (UTC)

I've capitalized 'Gymnasium' in two instances (in the 'Childhood and youth' section) where it's being used not simply as an English noun but rather (in 'Franz Josef Gymnasium'), as part of the name or type of school (in the combined expression 'Akademisches Gymnasium'). It really looked odd the way itw was (lowercase) to any native German reader/speaker, as the whole expression is meant to be in upperase in German. —Preceding unsigned comment added by 84.174.86.22 (talk) 18:00, 20 February 2008 (UTC)

The article mentions the son Wassik, but under "Children", Wassik is not listed. Is there a reason? — Preceding unsigned comment added by 2602:306:839A:9CC0:BCA0:6938:908A:A215 (talk) 18:50, 28 September 2016 (UTC)

Vassily = Wassik — Preceding unsigned comment added by Brienanni (talk • contribs) 21:45, 28 September 2016 (UTC)

Mathematician?
Can someone tell me how he was a mathematician? I did not know that, plus I don't see any mathematical professional activity in his bio, other than what in general a theoretical physicist would do. 71.103.51.35 (talk) 03:37, 27 March 2008 (UTC)Ur


 * Ehrenfest is called a mathematician because the MacTutor biography labels him as such, see http://www-history.mcs.st-andrews.ac.uk/Mathematicians/Ehrenfest.html . His field of research is called Mathematical physics. JdH (talk) 09:43, 27 March 2008 (UTC)


 * What is the ground for this claim is my question. MacTutor does not make that claim explicitly. His field of research was theoretical physics, not exactly mathematical physics. Reading the bio presented here nowhere do I see anything that would indicate that he was a mathematician. In addition, the Britannica says this about him: "Austrian theoretical physicist who helped clarify the foundations of quantum theory and statistical mechanics." Therefore, I think this claim is baseless and misleading. 71.103.0.107 (talk) 06:20, 1 April 2008 (UTC)Ur

He was not a mathematician his wife was who helped him with his work. This is very common in physics to label someone as a mathematician who could not possibly publish in a reputable mathematics journal. — Preceding unsigned comment added by 2610:E0:A040:CDFD:EC90:5BAB:A6D8:C4F8 (talk) 15:51, 22 November 2013 (UTC)


 * Sigh... "Reputable"... Please sign your edits. You are casting aspersions on the publication venue of his 1905 Habilitationsschrift now, Monatshefte für Mathematik 16: A33 (1905)... I believe the dual laebile pigeonholing issue has been settled by now, Talk:Ehrenfest_theorem. Why on earth revisit it? Whatever---make him a mathematically sophisticated puppeteer now. Cuzkatzimhut (talk) 16:13, 22 November 2013 (UTC)

Indeed, Ehrenfest was definitely not a mathematician, always lamenting his lack of formal mathematical skills. Brienanni (talk) 17:12, 22 November 2013 (UTC)

Bipolar disorder?
Walter M. Elsasser's biography has the following on Ehrenfest's behaviour:


 * "Shortly after receiving his Ph.D. in 1927, Walter received an unexpected invitation from Paul Ehrenfest, a well-known theoretical physicist, to be his assistant in Leiden, Holland, for a semester and possibly longer, and he accepted. He wondered who had recommended him since he did not know Ehrenfest and concluded that it must have been Oppenheimer. Shortly before leaving for Leiden, Walter received a long letter from Ehrenfest concerned not with physics but with the latter's psychological problems. Walter worried about this strange behavior of explaining the complexities of his soul to a stranger half his age, soon to be his assistant. Ehrenfest met him at the train station in Leiden and immediately took him on a long walk on which he recounted his psychological problems and appeared to be pleading for help. Walter offered to help as much as he could, but as events turned out this was not to be. [snip]
 * Walter developed pleasant friendships in Holland, but his relationship with Ehrenfest deteriorated as the latter changed from aggressiveness to downright hostility, for reasons Walter could not understand. One day after Walter had had a haircut with the usual barber's pomade, Ehrenfest came into his office and accused him of wearing perfume. Ehrenfest said he hated perfume, grew furious, and ordered Walter out. A few days later he told Walter to go back to Berlin. It is perhaps not unrelated to this behavior that a few years later Ehrenfest killed his retarded son and committed suicide."

This kind of change in mood, from depression to agitated/irrational actually suggests that Ehrenfest suffered of bipolar disorder. In The End of the Certain World: The Life and Science of Max Born by Nancy Thorndike Greenspan the following is said:
 * "For years, Ehrenfest had vacillated between high energy and deep depression, even telling Hedi in the past of a death wish."

This once again suggests bipolar disorder. JdH (talk) 18:52, 9 June 2008 (UTC)

Category removal
A number of applicable categories have been removed repeatedly, with comments in the edit summary of their being "inappropriate".

If the information on the subject's suicide, death by firearm, and killing of his Down syndrome child is in the article (which it currently is), there is no reason that applicable categories relating to these events shouldn't be added. There may be an overarching argument as to why these categories should be completely deleted, but this generally isn't done on an article-individual basis, but rather through a global WP:CFD process. Until a decision is made to delete these categories, they may be applied here if they are factually supported by the text of the article. To do otherwise can appear to be a form of selective censoring, which WP does not do.

I somewhat resent the suggestion that I am ruining an article which I had no part in building. In case you missed it, WP is the encyclopedia "anyone can edit". Editors may want to examine WP:OWN to disabuse any notion that those who work hardest on an article may control it. Good Ol’factory (talk) 22:57, 13 October 2008 (UTC)

Uncited quotes
There are a number of uncited quotations in this article, including: According to Einstein: "He was not merely the best teacher in our profession whom I have ever known; he was also passionately preoccupied with the development and destiny of men, especially his students. To understand others, to gain their friendship and trust, to aid anyone embroiled in outer or inner struggles, to encourage youthful talent — all this was his real element, almost more than his immersion in scientific problems".

Also, "His approach to science is best illustrated by what he wrote to Robert Oppenheimer in the summer of 1928, after Oppenheimer invited himself for an extended stay in Leiden: "If you intend to mount heavy mathematical artillery again during your coming year in Europe, I would ask you not only not to come to Leiden, but if possible not even to Holland, and just because I am really so fond of you and want to keep it that way. But if, on the contrary, you want to spend at least your first few months patiently, comfortably, and joyfully in discussions that keep coming back to the same few points, chatting about a few basic questions with me and our young people- and without thinking much about publishing (!!!)-why then I welcome you with open arms!! ".

Does anyone know where these quotes came from? We should either verify them with references or remove them from the article. Thanks. Safehaven86 (talk) 03:09, 12 September 2012 (UTC)
 * Those quotes come from Rowdy Boeyink's thesis, which is properly cited in the article, see http://www.rowdyboeyink.org/ehrenfest/ JdH (talk) 20:06, 17 November 2012 (UTC)


 * Ok, that citation should be added into the reference list and inline citations should be provided in the appropriate places within the article so that readers can verify the individual quotations. Thanks. Safehaven86 (talk) 03:12, 18 November 2012 (UTC)
 * A reference to Rowdy's thesis was included years ago when I first wrote the article; if you want inline references it is up to you to add those. JdH (talk) 11:51, 18 November 2012 (UTC)


 * I don't see any of those quotes at the link you provided. It is important to support these quotes with appropriate, verifiable inline citations. You removed the "citation needed" tags I added, citing this talk page. But we have not solved the problem. If you let me know exactly where these quotes are referenced in a source, I can add the inline citations that are needed to support these quotes. Thanks. Safehaven86 (talk) 19:49, 18 November 2012 (UTC)
 * !!?? It is right there, just click it! JdH (talk) 15:48, 19 November 2012 (UTC)


 * Yes, two of the three quotes are there, but not one of the quotes: "If you intend to mount heavy mathematical artillery again during your coming year in Europe, I would ask you not only not to come to Leiden, but if possible not even to Holland, and just because I am really so fond of you and want to keep it that way. But if, on the contrary, you want to spend at least your first few months patiently, comfortably, and joyfully in discussions that keep coming back to the same few points, chatting about a few basic questions with me and our young people- and without thinking much about publishing (!!!)-why then I welcome you with open arms!!" You removed a "citation needed" tag I added at the end of that quote, but as far as I can tell, a citation is still needed. Safehaven86 (talk) 16:24, 19 November 2012 (UTC)

conditional principle
Both Timeline of black hole physics and 1917 in science mention Ehrenfest's conditional principle for 3D space, but it is not mentioned in this article. I found what I think these are referring to here. I am curious about the significance of this paper and specifically how it relates to black holes. --Lasunncty (talk) 00:13, 15 September 2020 (UTC)