text:
Talk:Christiaan Barnard

Message from 2001
Christiaan Barnard died whilst on holiday in Paphos, Cyprus. Early reports claimed that he had died of a heart attack, although an autopsy showed that he died as the result of an acute asthma attack. — Preceding unsigned comment added by Robert Brook (talk • contribs) 14:56, 20 November 2001 (UTC)

ay
dis article iigh put mo info bout wat changed after he did da 1st heart transplant and wat waz medicine like before he did this — Preceding unsigned comment added by 65.3.68.194 (talk • contribs) 21:02, 15 October 2005 (UTC)

Arthritis caused by activities on ranch?
I am not aware of this claim, and suspect that it might need some verification, therefore added the {SectOR} — Preceding unsigned comment added by Fmalan (talk • contribs) 12:35, 6 November 2006 (UTC)

Id references
A couple of references are "Id.", can anyone elaborate on this? LeeVJ (talk) 21:34, 1 May 2008 (UTC)

Demihkov, Vladimir
An uncited statement on the Vladimir Demikhov article:

"Christiaan Barnard, who has performed the world's first heart transplant operation on from person to person in 1967, has twice visited the Demikhov's laboratory in 1960 and 1963. Christiaan Barnard through all his life considered Demikhov as his teacher."

If this were accurate, why is it not in the article? If it is inaccurate, it needs to be taken off of the other article. —Preceding unsigned comment added by 66.76.60.163 (talk) 02:52, 26 March 2009 (UTC)

Contradiction
This article says he divorced in 1969 and remarried in 1968. This is obviously wrong, but it's unclear (due to the lack of any citations) what the correct facts are. Can someone familiar with it please change it? Stifle (talk) 10:29, 8 June 2009 (UTC)

 * I've fixed this contradiction, and added appropriate citations. Jrt989 (talk) 17:26, 10 June 2009 (UTC)

Yes please change it ASAP due to researchers wanting facts. —Preceding unsigned comment added by 121.72.5.92 (talk) 05:07, 19 July 2010 (UTC)

Denise Darvall's Kidney
Prof. Barnard did not perform the kidney transplant for the young coloured boy, Jonathan Van Wyk. Jonathan's transplant was performed at another nearby hospital - Karl Bremer. The surgeons in Denise Darvall's donor operating theatre would have harvested her kidney. I work at The Heart of Cape Town Museum which commemorates the first heart transplant and we have a number of newspaper articles on the subject of her kidney donation. — Preceding unsigned comment added by Saffashells (talk • contribs) 15:40, 1 March 2011 (UTC)

 * Thanks for pointing this out. I've removed the sentence about the kidney donation to Van Wyk. I've also removed the sentence about the donor of the second heart transplant being coloured, as it disrupts the flow of the article without the previous sentence. Feel free to edit the article itself ... I'd be happy to assist you with adding more info and/or sources. Graham 87 01:56, 2 March 2011 (UTC)

 * Thanks very much Graham! Will do! — Preceding unsigned comment added by Saffashells (talk • contribs) 05:42, 10 March 2011 (UTC)

 * Not a problem. BTW, please sign your messages on talk pages with four tildes like this: "~". Graham 87 14:13, 10 March 2011 (UTC)

World's first heart transplant
The biography of Dr Christiaan Barnard says that he completed the world's first successful heart transplant in 1967; but the obituary of Dr Joseph Murray published in world newspapers today (November 27, 2012) says Murray succeded in this in 1962. Anyone know which is correct? — Preceding unsigned comment added by Arthur catton (talk • contribs) 09:31, 27 November 2012 (UTC)

 * The Christiaan Barnard biography is correct. I can't find an obituary of Joseph Murray that says he conducted the first heart transplant, but I can find some saying that he conducted the first organ transplant from an unrelated donor. Graham 87 15:08, 27 November 2012 (UTC)

James Hardy
Dr James Hardy of the University of Mississippi should be credited - at least mentioned - in this article. Barnard credited Hardy's work (first heart transplanted into a human) as his inspiration. Dr Hardy, in an attempt to save a dying man, transplanted the heart of a chimpanzee. The patient survived 90 minutes before the heart was rejected. Dr Hardy is also celebrated for his pioneering work in lung transplantation. http://en.wikipedia.org/wiki/James_Hardy_(surgeon) 98.173.18.11 (talk) 05:03, 14 February 2014 (UTC)Michael Van Velkinburgh

Should we begin this article with "second transplant, first widely-publicized . . . "
I mean the theory of being bold. Let's give both James Hardy and Christiaan Barnard their due. And the fact that we say the "first human-to-human" that's being a little bit cagey and hedging our bets. FriendlyRiverOtter (talk) 19:25, 3 November 2016 (UTC)

" . . . first successful . . . "
I don't know if we can say that with Louis Washkansky who lived eighteen days after the transplant. I guess we'd have to compare this to Louis's expected lifespan with conventional medicine and more conservative care. FriendlyRiverOtter (talk) 19:29, 3 November 2016 (UTC)

But Dr. Barnard's second transplant patient
On Jan. 2, 1968, Dr. Barnard performed a heart transplant on Philip Blaiberg, who lived another 19 months. I think this second operation can be viewed as more of a clear success. FriendlyRiverOtter (talk) 19:33, 3 November 2016 (UTC)

Did Chris promise first patient "80% chance"?
A Companion to Bioethics, Second Edition, Helga Kuhse, Peter Singer.

 * That's what this book is saying. We should include this in the article.  FriendlyRiverOtter (talk) 19:29, 8 November 2016 (UTC)

There's also a second book making this same claim:

Calculated Risks: How to Know When Numbers Deceive You, Gerd Gigerenzer, Simon & Schuster, 2002.

This has since been added to our article with both sources.FriendlyRiverOtter (talk) 17:38, 29 November 2016 (UTC)

---

http://digitalcommons.law.wne.edu/cgi/viewcontent.cgi?article=1287&context=lawreview

 * another potentially good article, long with a lot of info FriendlyRiverOtter (talk) 18:27, 13 December 2016 (UTC)

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I think Bernard was criticized for not having enough experience.
In fact, I think he was criticized specifically for not having dogs who survived longterm. Our article implies rather the opposite.

from Historical context section:

 * " .  .  .  Barnard experimented for several years with animal heart transplants.[1] More than 50 dogs received transplanted hearts.[1][6]  .  .  .  "

I have several other projects I'm working on, but this seems pretty important, too. FriendlyRiverOtter (talk) 17:33, 29 November 2016 (UTC)

Every Second Counts: The Race to Transplant the First Human Heart, Donald McRae, Putnam's Sons (Penguin Group), 2006, page 190:

 * " .  .  .  In the scrub room with his brother, Chris felt the old doubt rise up.  He was so close, but the task suddenly seemed impossibly daunting.  He thought of all the dogs he had lost after transplanting their hearts.  He was not like Shumway or Lower or Kantrowitz, with their long-term survivors.  .  .  " — Preceding unsigned comment added by FriendlyRiverOtter (talk • contribs) 17:56, 30 November 2016 (UTC)

A new heart, a new era, The Guardian, Donald McRae, June 25, 2006:

 * " .  .  .  By December 1967 Chris and Marius Barnard had transplanted 48 dog hearts in Cape Town - 250 fewer than Shumway and 210 fewer than Kantrowitz. Unlike the Americans, who restored their dogs to full health for a year and more, Barnard's best animal survival rate was 10 days.  .  .  " — Preceding unsigned comment added by FriendlyRiverOtter (talk • contribs) 18:45, 30 November 2016 (UTC)

Absent link, maybe findable:

 * — Preceding unsigned comment added by FriendlyRiverOtter (talk • contribs) 23:11, 30 November 2016 (UTC)

---

 * Before we were listing only Barnard' experience, but not that of Kantrowitz or Shumway. I think we should very much include both for fuller context and have made this change.  And Graham87, thanks for the help.  I want to do it right, as well as get credit for the work of finding references.  :-)  FriendlyRiverOtter (talk) 21:11, 3 December 2016 (UTC)

The Adrian Kantrowitz Papers, Replacing Hearts: Left Ventricle Assist Devices and Transplants, 1960-1970, National Institutes of Health, U.S. National Library of Medicine. " .  .  Two Stanford surgeons, Norman Shumway and Richard Lower, had started transplanting dog hearts while experimenting with hypothermia during the late 1950s.  .  "  reference posted by FriendlyRiverOtter (talk) 21:39, 3 December 2016 (UTC)

Worldwide context for heart transplants, early circus, discouragement, then serious work?
Norman E. Shumway, 83, Who Made the Heart Transplant a Standard Operation, Dies, New York Times, Lawrence Altman, Feb. 11, 2006.

' .  .  .  Almost immediately, dozens of surgeons around the world who had spent little time learning the technique on animals turned heart transplantation into a medical circus. Within a year, they performed about 100 human heart transplants.

'But those early transplants seldom achieved long-term success. It was easy enough to transplant a heart, as Dr. Shumway once said, "but it's what happens later with regard to the containment of rejection that makes the real difference." . .  .  '

 * We do state in our article's Additional heart transplants section that many surgeons did give up. FriendlyRiverOtter (talk) 18:03, 29 November 2016 (UTC)

Conflict between NIH source and what our article currently says
The Adrian Kantrowitz Papers, Replacing Hearts: Left Ventricle Assist Devices and Transplants, 1960-1970, National Institutes of Health, U.S. National Library of Medicine:

 * " .  .  Within several years, only Shumway's team at Stanford was attempting transplants."

And from our article's section Additional heart transplants:

 * "Barnard performed ten orthotopic transplants (1967–1973). He was also the first to perform a heterotopic heart transplant, an operation that he devised. Forty-nine consecutive heterotopic heart transplants were performed in Cape Town between 1975 and 1984."

-

It does look like a conflict, although perhaps much of Bernard's activity was during the worldwide flurry of activity during 1968. Now, we don't need to immediately adjudicate this. And we certainly don't need to guess. We can put both out there for our reader to see, respectfully treating our reader as an intelligent person and a potential colleague. And then, we do what we always do which is to continue to look for and find a goodly variety of references. FriendlyRiverOtter (talk) 22:24, 3 December 2016 (UTC)

-

http://www.samj.org.za/index.php/samj/article/view/5020/4123

This looks like it might be a pretty good source. FriendlyRiverOtter (talk) 01:04, 6 December 2016 (UTC)

a heterotopic ("piggy back") transplant involves leaving the diseased heart in patient's body while donor heart shares workload. Barnard pioneered this in '74
A tale of two hearts, Postgrad Medical Journal, July 27, 2016. " .  .  .  HHT [Heterotopic Heart Transplantation] involves transplanting the donor heart without removing the recipient heart, effectively forming a 'double heart'.  It was widely used in the pre-cyclosporine era when the donor was not strong enough (eg, the recipient had a much larger body) or the recipient had pre-existing pulmonary hypertension.  Christiaan Barnard performed the first HHT ('piggy back' transplant) in 1974 at the Groote Schuur Hospital in Cape Town.  .  .  "

 * This is a pretty substantial achievement which should be included in our article, and frankly pretty scary. FriendlyRiverOtter (talk) 03:36, 7 December 2016 (UTC)

--

Transplantation of the heart: An overview of 40 years’ clinical and research experience at Groote Schuur Hospital and the University of Cape Town, South African Medical Journal, "Part I. Surgical experience and clinical studies." J Hassoulas, Vol. 102, No. 6 (2012).

 * This is another good article. FriendlyRiverOtter (talk) 04:36, 7 December 2016 (UTC)

---

Christiaan Barnard: Single-minded surgeon, BBC, Sunday Sept. 2, 2001.

" .  .  .  These included double transplants, joining a healthy heart to the patient's to create a "double pump", designing artificial heart valves and using monkeys' hearts to keep alive desperately ill people.  .  .  "

 * And this BBC obituary has other good information as well. FriendlyRiverOtter (talk) 01:23, 15 December 2016 (UTC)

Barnard came up with slightly different technique while drowsily listening to music afternoon before first transplant?
Every Second Counts: The Race to Transplant the First Human Heart, Donald McRae, 2006, page 187:

" .  .  .  his Ink Spots records.  Barnard eventually became drowsy and he drifted in and out of sleep.  He claimed in subsequent accounts that his subconscious too over,  .  .  .  .  .  Barnard resolved that he would instead allow the septum to remain intact in the donor heart and that, rather than cutting away the entire back wall, he would slice open two small holes—giving him access to the two venae cavae and four pulmonary veins.  .  .  .  .  It was one more example of Barnard following his instincts—rather than testing his theories laboriously  .  .  .  .  .  "

 * well worth including in summarized form. FriendlyRiverOtter (talk) 17:38, 9 December 2016 (UTC)

 * and I have so included. FriendlyRiverOtter (talk) 19:06, 13 December 2016 (UTC)

Coert Venter and Bertie Bsoman were the two doctors who sought permission from Denise Darvall's father
Every Second Counts, Don McRae, 2006, page 189:

"The doctors had sedated him [Edward Darvall] earlier that evening. He was still in a daze when Coert Venter knocked gently and opened the office door.  Venter was accompanied by another doctor on the transplant team, Bertie Bosman, who, before speaking, made him rest on the couch.  Bosman revealed gently that there was nothing more they could do for Denise.  .  .  .  .  There was a man in the hospital, Bosman said, who they could still save.  .  .  .  .  Darvall remained quiet.  Bosman and Venter withdrew, stressing that he should take as long as he needed to consider their request.  They would understand if he declined to give his consent.  .  .  "

 * I have included a summarized form of this. Before, our article had stated that Barnard had been the one who had asked for consent of the family, and that's just not accurate.  FriendlyRiverOtter (talk) 18:13, 9 December 2016 (UTC)

McRae's book brackets approximately 6 hours for Chris's first transplant, two other sources say 5 hours
And yet our article currently states: "The operation lasted nine hours."

with the two sources:

 * Memories of the Heart". Daily Intelligencer. Doylestown, Pennsylvania. 29 November 1987. p. A-18

 * Every Second Counts, Don McRae, 2006.

The first source I can't find online. The second source, McRae's book, does not say this. At least not in the central part where it describes Chris Barnard's first transplant, the prep described on page 190 and the operation itself on pages 191-196. FriendlyRiverOtter (talk) 17:36, 16 December 2016 (UTC)

-

page 190: "It was almost midnight  .  .  .  "  And he still has to shower, dress in scrubs, and go visit Louis Washkansky.

page 196: "At 6:13 a.m. they made another fretful attempt.  'Cut the pump,' Barnard said.  There was another hesitation in the heart, as if it was deciding whether or not to live in its huge new body, and then it began to beat more strongly.  .  .  "

So, a definitely time of success, although they still needed to close up Louis's chest. But no definite time for the beginning.

 * So, I'm going to clear up an obvious mistake and state something of the sort "approximately 6 hours." And, I welcome additional sources!  Please dive in and help if this topic interests you.  FriendlyRiverOtter (talk) 17:44, 16 December 2016 (UTC)

-

1967: First Heart Transplant Patient Goes Under the Knife, Haaretz, This Day in Jewish History, David B. Green, 3.12.2013

" .  .  .  Christiaan Barnard, who had studied transplant surgery in the United States and had already performed heart replacements on some 200 dogs, [48 dogs, per McRae's article in the Guardian]  .  .  .  "

" .  .  .  The five-hour operation, carried out by a team of 30 led by Barnard, began at 1 A.M. on December 3, and reached its emotional peak when Barnard applied an electrical current to the transplanted heart and it began to beat within Washkansky’s body.  .  .  "

 * Okay, so roughly in line with McRae's book. I'm going to stick with "approximately six hours."  It's a nice round number.  Plus, this is a popularly written article with at least one mistake.  It's a bio pict on the patient, which is important, but it's not focusing on the technical aspects of the operation.  FriendlyRiverOtter (talk) 19:12, 16 December 2016 (UTC)

--

Christiaan Neethling Barnard, South African History Online, updated 11 Jan 2017.

" .  .  .  The operation lasted five hours and the patient survived,  .  .  .  "

 * Since we have two sources saying five hours, I'm now inclined to go in that direction. FriendlyRiverOtter (talk) 19:49, 5 May 2017 (UTC)

Per McRae's book, unclear whether Chris or Marius injected potassium to stop brain-dead Darvall's heart
Yes, the doctors seemed quite confident that Denise Darvall was brain dead, which to me is the central ethical question. And I hope for you, too! :-)

Our article currently states: "at his brother Marius Barnard's urging, Christiaan had injected potassium into her heart" and using McRae's book as the reference. Whereas McRae's book does not definitely says this, almost hints at the opposite:

 * " .  .  .  Once stilled, Marius argued, they could remove the heart quickly and implant it in Washkansky, offering more hope for success than if they adhered to outdated medical ethics.  Chris knew that Marius was right.  He nodded his assent.  Marius reached for the potassium while O'Donovan watched silently.  It was a decision that they swore would always remain secret from the world outside.  .  .  " --Every Second Counts, McRae, page 192.

Okay, admittedly, some doubt on who actually injected the potassium. Will look for additional sources. FriendlyRiverOtter (talk) 18:35, 16 December 2016 (UTC)

--

1967: First Heart Transplant Patient Goes Under the Knife, Haaretz, This Day in Jewish History, David B. Green, 3.12.2013

" .  .  .  According to a detailed article about Washkansky’s historic transplant by Dr. Irving Lissoos, in the journal Jewish Affairs,  .  .  "

" .  .  .  Christiaan Barnard, who had studied transplant surgery in the United States and had already performed heart replacements on some 200 dogs, [48 dogs, per McRae's article in the Guardian]  .  .  .  "

" .  .  .  At the time, however, as standards for determining “brain death” were not yet agreed upon, a body's organs could be harvested only after “whole-body death” was declared.

"In Darvall’s case, it was only when Barnard injected potassium into her heart that it stopped beating, at which point it could be removed. (It was Christiaan Barnard’s brother Marius, also a surgeon, who urged him to induce heart stoppage, and who revealed this only in 2006.) .  .  .  "

 * This source is saying Chris injected the potassium, although it's a bio piece on the patient. FriendlyRiverOtter (talk) 18:49, 16 December 2016 (UTC)

MAJOR CHANGE. More than enough references to say Hardy performed first heart transplant and Barnard the second.
Heart Transplantation in Man: Developmental Studies and Report of a Case, JAMA (Journal of the American Medical Association), James D. Hardy, MD; Carlos M. Chavez, MD; Fred D. Kurrus, MD; William A. Neely, MD; Sadan Eraslan, MD; M. Don Turner, PhD; Leonard W. Fabian, MD; Thaddeus D. Labecki, MD; 188(13): 1132-1140; June 29, 1964.

A brief history of cross-species organ transplantation, Baylor University Medical Center Proceedings, David K. C. Cooper MD, PhD, 2012 Jan; 25(1): 49–57.

Every Second Counts: The Race to Transplant the First Human Heart, Donald McRae, G.P. Putnam Son's (Penguin Group), 2006, page 123.

James Hardy, Obituary, The Telegraph [UK], March 20, 2003.

 * Yes, Hardy performed a xenotransplant in which he inserted a chimp's heart into a seriously-ill and in fact dying's man's chest. But it wasn't any kind of experiment on someone already dead.  It was a real transplant into a human patient with the attempt to extend their life.  I think this counts as the first.  FriendlyRiverOtter (talk) 18:23, 18 January 2017 (UTC)
 * Yes, and we can say that in the body of the article, where there is room for such details. But an article's lead section is supposed to be a broad overview of the page, so I've taken a crack at improving it to this end. (I don't know anything about this subject and only have this article on my watchlist to deal with vandalism). Statements in the lead section also don't necessarily need to be referenced, especially if they are uncontroversial and already sourced in the body of the article. Graham 87 06:43, 19 January 2017 (UTC)
 * I like your lead and think you did a fine summary! And on thinking it over, I probably went on too long about Hardy in the lead.  Have some ideas for being briefer, think you might like it. FriendlyRiverOtter (talk) 19:48, 19 January 2017 (UTC)
 * Thanks! Yes, your edit works well. Graham 87 08:02, 20 January 2017 (UTC)
 * You're very welcome. And thank you for your kind words.  :-)  FriendlyRiverOtter (talk) 18:42, 20 January 2017 (UTC)

informally taught surgeon Naki Hamilton
Film on black surgeon in first heart transplant team rekindles controversy, The Guardian (UK), David Smith, 31 May 2009.

Naki Hamilton worked as a cleaner and gardener at Groote Schuur Hospital. One day he was invited to help with an experiment on a giraffe. And from this beginning, he became principal lab technician and ended up teaching some 3,000 surgeons. Wow.

' .  .  .  Hidden Heart tells the story of Hamilton Naki, a gardener turned self-taught surgeon who became a key assistant to pioneering heart surgeon Dr Christiaan Barnard in his organ transplant programme. . .  '

' .  .  .   "Hamilton Naki had better technical skills than I did," Barnard said. "He was a better craftsman than me, especially when it came to stitching, and had very good hands in the theatre." . .  .  '

' .  .  .  The Swiss-made documentary reopens the debate over Naki's claim that he participated in the historic first heart transplant. After Naki's death, aged 78 in 2005, the Economist published an obituary saying Naki assisted in the transplant, but later published an amendment saying it had been assured by surgeons at Groote Schuur hospital that Naki was nowhere near the operating theatre at the time. . .  '

 * This is one good source, or let's say a pretty okay source. Going to try to summarize.  FriendlyRiverOtter (talk) 21:31, 8 February 2017 (UTC)

review of McRae's EVERY SECOND COUNTS: THE RACE TO TRANSPLANT THE FIRST HUMAN HEART
Every Second Counts: The Race to Transplant the First Human Heart, Donald McRae, Berkley Publishing (Penguin Group), 2006.

http://jnm.snmjournals.org/content/48/9/1571.short

 * This review includes the joke about the chauffeur and the lecture, which joke Barnard did tell at a big meeting, but the book describes the story itself as an apocryphal anecdote (p. 268). This review plays it straight and seems to think it really happened.  Hopefully, it's stronger on the medical aspects.  FriendlyRiverOtter (talk) 19:53, 25 February 2017 (UTC)

-

http://www.publishersweekly.com/978-0-399-15341-9

 * Since we heavily use McRae's book as a reference, both myself and previous editors, I think it would be a good idea to include a couple of reviews of it. FriendlyRiverOtter (talk) 21:42, 23 February 2017 (UTC)

Barnard working with Vince Gott in Minneapolis
Vince looks like a somewhat less famous person, but a person who acted as a bridge to pull Chris over to heart work. At least this is the conclusion in McRae's book. I want to look for other sources as well. FriendlyRiverOtter (talk) 20:19, 24 February 2017 (UTC)

Pacemaker pioneer now lives with device, CNN, Elizabeth Landau and Evelio Contreras, April 26, 2013.

" .  .  .  Chris Barnard was trained by Dr. Lillehei, so I knew him well.  .  .  "

" .  .  .  That was a problem, actually, for almost two years after Dr. Lillehei started his surgery. It was in the fall of 1956 that a young physiologist, Dr. Jack Johnson at the University of Minnesota, said you know, to Dr. Lillehei and the rest of them, 'I've been pacing frog hearts for five years with an electrical stimulator. Why don't you use that?'

"I went over and borrowed this electrical stimulator from Jack Johnson, and we were able to create heart block in a research animal very easily. It's just a matter of putting a wire in the heart and a wire in the skin, and connecting it up to Dr. Johnson's electrical stimulator, and it worked. And then Dr. Lillehei started using that in January of 1967 [1957, per the below source], and that was really the start of the pacemaker.

"At that time, there was not a portable pacemaker. And these children could not go home with a pacemaker, but Mr. Earl Bakken, who was the president of a small company called Medtronic in Minneapolis, then built a portable, battery powered pacemaker that these children could use.

"We never envisioned at that time that there would be literally hundreds of thousands of adults who could benefit from the pacemaker. I in fact received a pacemaker myself five years ago for heart block. .  .  "

 * Great stuff on the pacemaker, but only brief mention of Barnard. And notice that CNN looks like it got the date wrong for the introduction of the portable pacemaker in the United States.  It's hard to find the perfect reference!  In fact, no such thing exists.  That's why it's good to go for a variety of references.  FriendlyRiverOtter (talk) 20:20, 25 February 2017 (UTC)

---

In Memoriam

C. Walton Lillehei, the “Father of Open Heart Surgery”

Circulation, 1999;100:1364-1365.

http://circ.ahajournals.org/content/100/13/1364

" .  .  .  In 1957, with Earl Bakken (the cofounder of Medtronic), he introduced the first transistorized, wearable permanent cardiac pacemaker for clinical use.  .  .  " FriendlyRiverOtter (talk) 21:08, 28 February 2017 (UTC)

journal publications for Barnard's first couple of heart transplants.
Barnard CN. The operation. A human cardiac transplant: an interim report of a successful operation performed at Groote Schuur Hospital, Cape Town.; Cape Town. S Afr Med J 1967 Dec 30;41(48): 1271-74.

http://www.samj.org.za/index.php/samj/article/view/5020/4123

https://www.ncbi.nlm.nih.gov/pubmed/4170370

--

Barnard CN. Human cardiac transplantation. An evaluation of the first two operations performed at Groote Schuur Hospital, Cape Town. Am J Cardiol 1968;22:584-596.

http://www.samj.org.za/index.php/samj/article/view/5020/4123

 * Will come back to this when I have more time. Definitely should be in our article.  FriendlyRiverOtter (talk) 18:17, 1 March 2017 (UTC)

other potentially good journal articles
http://www.scielo.br/scielo.php?pid=S0102-76382008000100027&script=sci_arttext&tlng=en

 * yes, even though it's Brazilian, this seems like a really good historical overview. FriendlyRiverOtter (talk) 22:24, 1 March 2017 (UTC)

To what position did Groote Schuur appoint Barnard in 1958?
Christiaan Barnard: his first transplants and their impact on concepts of death, Raymond Hoffenberg, BMJ, 2001 Dec 22; 323(7327): 1478–1480.

 * ' .  .  What was relatively unusual was the presence in the medical school of a strong department of experimental surgery, founded with remarkable perspicacity some 30 years earlier. In 1958 Barnard was appointed as its head, and he began to develop an ambitious programme of open heart surgery.  .  '

And yet our article, including our lead states:

 * ' .  .  in 1958, Barnard was appointed cardiothoracic surgeon at the Groote Schuur Hospital,  .  .  '

This is a little bit different. The same part in the body cites McRae's book without giving a page number. Maybe the next step is to see if this part can be found. FriendlyRiverOtter (talk) 18:00, 17 March 2017 (UTC)

I cannot find this part in McRae's book. Re-read the part where Chris returns to Groote Schuur from Minneapolis (pages 60-63). I also used search function on google books to search internally for the words cardiothoracic and appointed. Still could not find it. FriendlyRiverOtter (talk) 17:59, 24 March 2017 (UTC)

---

Dictionary of African Biography, Volume 6, Emmanuel Kwaku Akyeampong, Henry Louis Gates, Jr., editors-in-chief, Barnard, Christiaan Neethling, Anne Digby, Oxford University Press, 2012.

 * " .  .  before returning in 1958 to a joint post at the University of Cape Town and Groote Schuur Hospital, where, as well as surgical work and teaching, he did advanced work in research laboratories in perfecting on dogs surgical techniques he later used for human organ transplantation.  .  '

 * " .  .  Barnard was associate professor and head of Groote Schuur's Department of Cardiothoracic Surgery when, in a five-hour operation on 3 December 1967, he performed the world's first human-to-human heart transplant.  He was supported by a large team that included his younger brother, Marius, also a surgeon.  .  .  "

This provides a possible explanation. First Barnard was head of the Dept. of Experimental Surgery, and then at the time of the '67 operation, he was head of Dept. of Cardiothoracic Surgery. FriendlyRiverOtter (talk) 18:24, 24 March 2017 (UTC)

straightforward about controversial information, and people still have idea Barnard was first.
Our lead currently begins:
 * Christiaan Neethling Barnard (8 November 1922 – 2 September 2001) was a South African cardiac surgeon who performed the world's first human-to-human heart transplant on December 3, 1967,[1] and the second overall heart transplant (Hardy did a xenotransplant in 1964[2]). ..

I think we should switch the order and say "second overall" first. That way, people who read quickly, and many wiki users do, will get the right idea. FriendlyRiverOtter (talk) 16:55, 28 March 2017 (UTC)
 * I think that's going too far, and I've reverted it as such. As the relevant part of the Manual of Style says, "The lead sentence should describe the person as he or she is commonly described in reliable sources", which almost always describe him as the first person to perform a human-to-human heart transplant; that is what he was famous for. An illustrative example is his Guardian obituary, which starts like so: "The South African surgeon Christiaan Barnard, who has died aged 78, led the surgical team that performed the first human-to-human heart transplant on December 2-3 1967. The operation captured public imagination around the globe, and, literally overnight, Barnard became one of the best known people in the world." Therefore, I think that should be the first thing mentioned. Graham 87 07:19, 29 March 2017 (UTC)
 * I don't like it. It's like we're feeding into an urban legend.  "first human-to-human" is too much like a finesse.  As an analogy, what if something was widely believed about Johannes Gutenberg which was an urban legend type situation of only being partially correct and in fact misleading?  In the body of the article, we could talk about the widespread belief if we had the sources, but in the lead, I think we should just very matter-of-factly state the accurate information.  Hardy's operation counts as a real transplant, and '64 is before '67, and it's hard to get past that.  FriendlyRiverOtter (talk) 21:04, 29 March 2017 (UTC)
 * I think we're already matter-of-fact enough about it by mentioning Hardy in the lead at all (let alone in the first sentence). The principle of least astonishment applies here, especially the part that says "The average reader should not be shocked, surprised, or overwhelmingly confused by your article." We don't want people to start reading the article and go "Christiaan Barnard was the second what?" We want to gently ease readers into the fact that there was a previous heart transplant involving a human patient, and I think the lead as it currently is achieves that quite nicely. I speak here as a general reader and experienced editor who admires the thoroughness of your research but knows nothing about this subject; As I've hinted that before, I only have this article on my watchlist because of [//en.wikipedia.org/w/index.php?oldid=329425720&diff=prev some] [//en.wikipedia.org/w/index.php?title=Christiaan_Barnard&diff=next&oldid=329425720 vandalism] to it that I found while reading it back in 2009. Graham 87 05:37, 30 March 2017 (UTC)
 * I appreciate your first-rate editing, too! :-)  I might simply add 'James' so that it's clear that Hardy is a real person (and not a hospital or institution).  Other than that, I'm going to pull back and not make any changes for a while.  The funny thing is, when I've asked about a half dozen people, Do you know who did the first heart transplant?, the most common answer has been Denton Cooley? ! ?  With this given as a question, the person obviously not knowing, and that's perfectly okay, too.  FriendlyRiverOtter (talk) 20:34, 30 March 2017 (UTC)
 * Re: my recent relevant revert: I used WikiBlame to figure out that Hardy was removed from the lead in this edit by Kablammo. TBH I can't say I'm that keen on putting it back. Graham 87 03:29, 28 November 2018 (UTC)
 * I still think we're not doing a good job informing our readers who know some or a medium amount about the topic. And that's going to be a fair number of readers.FriendlyRiverOtter (talk) 17:01, 28 November 2018 (UTC)
 * I don't think this issue is important enough to sacrifice the flow of the article's introductory sentence. Graham 87 05:28, 29 November 2018 (UTC)
 * The fact that we have this specific disagreement I think is potentially a good thing, as I'm remembering we usually work together pretty well. And I think I see where you're coming from about not wanting to stumble our reader, especially not at the very beginning.  And I hope you see where I'm coming from, that if our reader comes to our article with a common misconception and leaves with that very same misconception, we haven't done a very good job. I'll tell you what.  I'm going to put on my thinking cap and try to come up with a new method or approach, and perhaps you might do the same, time and interest permitting of course.  And then, we'll see how it works and take it from there. :-) FriendlyRiverOtter (talk) 17:44, 1 December 2018 (UTC)

 * The operation that took medicine into the media age, BBC, Dr Ayesha Nathoo (Centre for Medical History, University of Exeter), 3 Dec. 2017: 'News of the first human-to-human heart transplant, led by South African surgeon Christiaan Barnard, made headlines around the world. Journalists and film crews flooded into Cape Town's Groote Schuur Hospital, soon making Barnard and Washkansky household names. Initial reports widely hailed the operation as "historic" and "successful", though Washkansky only survived a further 18 days. The first heart transplant attracted unprecedented media attention for a medical undertaking  .  .  .  ' Photo caption: 'Louis Washkansky was the first person to have a heart transplant' A good source regarding how much publicity Barnard and his patient Washkansky received, but also an example of how easy it is to blur from first "human-to-human" to first transplant.  The photo caption even identifies Washkansy as the first person, which we know is simply untrue.  Boyd Rush was the first person to receive a heart transplant. FriendlyRiverOtter (talk) 16:41, 4 December 2018 (UTC)

-

Another source which states Barnard's first transplant received enormous publicity:

Organ Donation, GlobalViewpoints, Introduction, edited by Margaret Haerens, Detroit, New York, San Francisco, New Haven, Conn., Waterville, Maine, London: Greenhaven Press, 2013.

 * The Introduction of this book includes James Hardy's 1963 lung transplant, but then does not mention his 1964 heart transplant (!) (!) (!) FriendlyRiverOtter (talk) 19:07, 12 December 2018 (UTC)

Transplant: From Myth to Reality, Nicholas L. Tilney, New Haven, Connecticut, U.S., and London, England, UK: Yale University Press, 2003, pages 160-61.

'In December 1967 Christiaan Barnard. . .  The worldwide publicity surrounding this event pushed the donor issue to the forefront and caused many to rethink their beliefs about death and to consider the state of brain death for the first time. . .  '

 * Yes, because Barnard's patient Louis Washkansky lived!, at least initially, Barnard was the doctor who got all the publicity. FriendlyRiverOtter (talk) 22:14, 26 January 2019 (UTC)

So, the best I currently have is to describe Barnard as performing "the first highly-publicized heart transplant and the first one in which the patient regained consciousness . . . " And then talk about Dr. James Hardy and patient Boyd Rush in the Historical Context section and in a footnote. That's the best I have right now. If you have a better idea, please, by all means, run with it. FriendlyRiverOtter (talk) 00:33, 8 February 2019 (UTC)
 * That works for me. Graham 87 03:01, 8 February 2019 (UTC)
 * And please jump in when you have ideas for improvements. I think we often work well together.  :-)  FriendlyRiverOtter (talk) 23:32, 8 February 2019 (UTC)

Weekly Review 1978 "interview"
An editor has inserted a new passage based on a source given as "Hilary, Ng'weno (May 19, 1978). "I Would Split South Africa Into Two Parts - Equitably". The Weekly Review: 16–17." and myself have POV concerns about this passage, starting with the question of whether a surgeon's views on politics are sufficiently notable for inclusion at all. Samsara 09:52, 14 August 2017 (UTC)

 * So let me get this straight, you allow a section on his public life to stand, which paints his views on race positively. But when this contribution is added (that goes aginst the paragraph you let stand), now all of a sudden, you have a problem with his views on the topic being on the wiki. What level of hypocrisy is that?Zamorin1851 (talk) 02:07, 15 August 2017 (UTC)
 * If this wiki article on the surgeon is going to contains a paragraph on his views on apartheid, I see no reason why additional material cannot be added. The words in use are largely quotes from the interview he himself did willingly in May of 1978. Seeing that you allowed the previously existing paragraph to remain which paints him in positive light, I can understand the angst you show to the content from this interview which goes the opposite direction.Zamorin1851 (talk) 02:07, 15 August 2017 (UTC)
 * I cannot find any evidence of a "Weekly Review" matching the publication dates. What are the publisher and place of publication? Samsara 10:08, 14 August 2017 (UTC)
 * The wiki page for Hilary Ng'weno states clearly that the magazine ran from 1975 to 1999. Does 1978 ran in between those two years and is that not glaringly obvious?Zamorin1851 (talk) 09:43, 15 August 2017 (UTC)

 * I do see it irks some people to see some very negative views from Dr. Barnard. So much that only a physical copy of the magazine meets your requirements for fitness.Zamorin1851 (talk) 09:45, 15 August 2017 (UTC)

 * Do you expect to find online references to everything every published? Does it mean that if you, the almighty aren't aware of a publication, that it probably does not exist? How does one prove the existence of a publication which is regional and probably never known to you. And even after confirming the previous existence of the magazine itself, do you mean that unless you see the particular edition in question the contribution referencing it cannot be allowed?Zamorin1851 (talk) 02:07, 15 August 2017 (UTC)
 * A simple google search does show;
 * the magazine actually did exist
 * the interviewer was the publisher and is not made upZamorin1851 (talk) 01:52, 15 August 2017 (UTC)

 * The Weekly Review was a weekly news magazine published by Hilary Ng'weno and there is a Wikipedia article on him. The article states clearly his role in the now defunct magazine. Since you accuse me of probably putting out a fake interview, are you now going to ask for a physical copy of the publication? How else do I prove the existence of this now defunct magazine?--Zamorin1851 (talk) 01:52, 15 August 2017 (UTC)
 * Ng'weno is mentioned here, as is the Weekly Review. It is also mentioned at Hilary Ng'weno Cas Liber (talk · contribs) 10:47, 14 August 2017 (UTC)
 * Thanks for that - only just saw that you responded. Any idea of how we can obtain the material? And what's your take on notability? Samsara 10:56, 14 August 2017 (UTC)
 * The interviewer was the publisher of the magazine itself. His name and his connection not just to the magazine but Kenyan journalism is easily verifiable by the sheer volume of references you can find on the web.Zamorin1851 (talk) 01:54, 15 August 2017 (UTC)
 * Hmm, the interviewer looks notable, so I'd think it was, as it adds some depth to his views on South African politics at the time. We can ask the IP to maybe scan or photograph the article and send or post online I guess....Cas Liber (talk · contribs) 11:48, 14 August 2017 (UTC)
 * I cannot post a screenshot of the magazine due to copyright restrictions.Zamorin1851 (talk) 01:54, 15 August 2017 (UTC)
 * Yup, one of the first things I did. ;) Samsara 15:04, 14 August 2017 (UTC)

 * If this wiki article on the surgeon is going to contains a paragraph on his views on apartheid, I see no reason why additional material cannot be added. The words in use are largely quotes from the interview he himself did willingly in May of 1978. Seeing that you allowed the previously existing paragraph to remain which paints him in positive light, I can understand the angst you show to the content from this interview which goes the opposite direction.Zamorin1851 (talk) 01:52, 15 August 2017 (UTC)
 * Yeah, I'd say include it as well. We have offline sources for other things that we don't demand proof of. Would be nice but is not essential. Cas Liber (talk · contribs) 02:50, 15 August 2017 (UTC)

title: Talk:Christiaan Barnard


text:
Commutator

In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory.

Group theory
The commutator of two elements, $g$ and $h$, of a group $G$, is the element

This element is equal to the group's identity if and only if $g$ and $h$ commute (that is, if and only if $[g, h] = g^{−1}h^{−1}gh$).

The set of all commutators of a group is not in general closed under the group operation, but the subgroup of G generated by all commutators is closed and is called the derived group or the commutator subgroup of G. Commutators are used to define nilpotent and solvable groups and the largest abelian quotient group.

The definition of the commutator above is used throughout this article, but many other group theorists define the commutator as

Identities (group theory)
Commutator identities are an important tool in group theory. The expression $gh = hg$ denotes the conjugate of $a$ by $x$, defined as $[g, h] = ghg^{−1}h^{−1}$.
 * 1) $$x^y = x[x, y].$$
 * 2) $$[y, x] = [x,y]^{-1}.$$
 * 3) $$[x, zy] = [x, y]\cdot [x, z]^y$$ and $$[x z, y] = [x, y]^z \cdot [z, y].$$
 * 4) $$\left[x, y^{-1}\right] = [y, x]^{y^{-1}}$$ and $$\left[x^{-1}, y\right] = [y, x]^{x^{-1}}.$$
 * 5) $$\left[\left[x, y^{-1}\right], z\right]^y \cdot \left[\left[y, z^{-1}\right], x\right]^z \cdot \left[\left[z, x^{-1}\right], y\right]^x = 1$$ and $$\left[\left[x, y\right], z^x\right] \cdot  \left[[z ,x], y^z\right] \cdot \left[[y, z], x^y\right] = 1.$$

Identity (5) is also known as the Hall–Witt identity, after Philip Hall and Ernst Witt. It is a group-theoretic analogue of the Jacobi identity for the ring-theoretic commutator (see next section).

N.B., the above definition of the conjugate of $a$ by $x$ is used by some group theorists. Many other group theorists define the conjugate of $a$ by $x$ as $a^{x}$. This is often written $${}^x a$$. Similar identities hold for these conventions.

Many identities that are true modulo certain subgroups are also used. These can be particularly useful in the study of solvable groups and nilpotent groups. For instance, in any group, second powers behave well:
 * $$(xy)^2 = x^2 y^2 [y, x][[y, x], y].$$

If the derived subgroup is central, then
 * $$(xy)^n = x^n y^n [y, x]^\binom{n}{2}.$$

Ring theory
Rings often do not support division. Thus, the commutator of two elements a and b of a ring (or any associative algebra) is defined differently by
 * $$[a, b] = ab - ba.$$

The commutator is zero if and only if a and b commute. In linear algebra, if two endomorphisms of a space are represented by commuting matrices in terms of one basis, then they are so represented in terms of every basis. By using the commutator as a Lie bracket, every associative algebra can be turned into a Lie algebra.

The anticommutator of two elements $a$ and $b$ of a ring or associative algebra is defined by
 * $$\{a, b\} = ab + ba.$$

Sometimes $$[a,b]_+$$ is used to denote anticommutator, while $$[a,b]_-$$ is then used for commutator. The anticommutator is used less often, but can be used to define Clifford algebras and Jordan algebras and in the derivation of the Dirac equation in particle physics.

The commutator of two operators acting on a Hilbert space is a central concept in quantum mechanics, since it quantifies how well the two observables described by these operators can be measured simultaneously. The uncertainty principle is ultimately a theorem about such commutators, by virtue of the Robertson–Schrödinger relation. In phase space, equivalent commutators of function star-products are called Moyal brackets and are completely isomorphic to the Hilbert space commutator structures mentioned.

Identities (ring theory)
The commutator has the following properties:

Lie-algebra identities

 * 1) $$[A + B, C] = [A, C] + [B, C]$$
 * 2) $$[A, A] = 0$$
 * 3) $$[A, B] = -[B, A]$$
 * 4) $$[A, [B, C]] + [B, [C, A]] + [C, [A, B]] = 0$$

Relation (3) is called anticommutativity, while (4) is the Jacobi identity.

Additional identities

 * 1) $$[A, BC] = [A, B]C + B[A, C]$$
 * 2) $$[A, BCD] = [A, B]CD + B[A, C]D + BC[A, D]$$
 * 3) $$[A, BCDE] = [A, B]CDE + B[A, C]DE + BC[A, D]E + BCD[A, E]$$
 * 4) $$[AB, C] = A[B, C] + [A, C]B$$
 * 5) $$[ABC, D] = AB[C, D] + A[B, D]C + [A, D]BC$$
 * 6) $$[ABCD, E] = ABC[D, E] + AB[C, E]D + A[B, E]CD + [A, E]BCD$$
 * 7) $$[A, B + C] = [A, B] + [A, C]$$
 * 8) $$[A + B, C + D] = [A, C] + [A, D] + [B, C] + [B, D]$$
 * 9) $$[AB, CD] = A[B, C]D + [A, C]BD + CA[B, D] + C[A, D]B =A[B, C]D + AC[B,D] + [A,C]DB + C[A, D]B$$
 * 10) $$A, C], [B, D = [[[A, B], C], D] + [[[B, C], D], A] + [[[C, D], A], B] + [[[D, A], B], C]$$

If $A$ is a fixed element of a ring R, identity (1) can be interpreted as a Leibniz rule for the map $$\operatorname{ad}_A: R \rightarrow R$$ given by $$\operatorname{ad}_A(B) = [A, B]$$. In other words, the map adA defines a derivation on the ring R. Identities (2), (3) represent Leibniz rules for more than two factors, and are valid for any derivation. Identities (4)–(6) can also be interpreted as Leibniz rules. Identities (7), (8) express Z-bilinearity.

From identity (9), one finds that the commutator of integer powers of ring elements is:
 * $$[A^N, B^M] = \sum_{n=0}^{N-1}\sum_{m=0}^{M-1} A^{n}B^{m} [A,B] B^{N-n-1}A^{M-m-1} = \sum_{n=0}^{N-1}\sum_{m=0}^{M-1} B^{n}A^{m} [A,B] A^{N-n-1}B^{M-m-1}$$

Some of the above identities can be extended to the anticommutator using the above ± subscript notation. For example:
 * 1) $$[AB, C]_\pm = A[B, C]_- + [A, C]_\pm B$$
 * 2) $$[AB, CD]_\pm = A[B, C]_- D + AC[B, D]_- + [A, C]_- DB + C[A, D]_\pm B$$
 * 3) $$A,B],[C,D=[[[B,C]_+,A]_+,D]-[[[B,D]_+,A]_+,C]+[[[A,D]_+,B]_+,C]-[[[A,C]_+,B]_+,D]$$
 * 4) $$\left[A, [B, C]_\pm\right] + \left[B, [C, A]_\pm\right] + \left[C, [A, B]_\pm\right] = 0$$
 * 5) $$[A,BC]_\pm = [A,B]_- C + B[A,C]_\pm = [A,B]_\pm C \mp B[A,C]_-$$
 * 6) $$[A,BC] = [A,B]_\pm C \mp B[A,C]_\pm$$

Exponential identities
Consider a ring or algebra in which the exponential $$e^A = \exp(A) = 1 + A + \tfrac{1}{2!}A^2 + \cdots$$ can be meaningfully defined, such as a Banach algebra or a ring of formal power series.

In such a ring, Hadamard's lemma applied to nested commutators gives: $e^A Be^{-A} \ =\ B + [A, B] + \frac{1}{2!}[A, [A, B]] + \frac{1}{3!}[A, [A, [A, B]]] + \cdots \ =\ e^{\operatorname{ad}_A}(B). $ (For the last expression, see Adjoint derivation below.) This formula underlies the Baker–Campbell–Hausdorff expansion of log(exp(A) exp(B)).

A similar expansion expresses the group commutator of expressions $$e^A$$ (analogous to elements of a Lie group) in terms of a series of nested commutators (Lie brackets), $$e^A e^B e^{-A} e^{-B} = \exp\!\left( [A, B] + \frac{1}{2!}[A{+}B, [A, B]] + \frac{1}{3!} \left(\frac{1}{2} [A, [B, [B, A]]] + [A{+}B, [A{+}B, [A, B]]]\right) + \cdots\right). $$

Graded rings and algebras
When dealing with graded algebras, the commutator is usually replaced by the graded commutator, defined in homogeneous components as
 * $$[\omega, \eta]_{gr} := \omega\eta - (-1)^{\deg \omega \deg \eta} \eta\omega.$$

Adjoint derivation
Especially if one deals with multiple commutators in a ring R, another notation turns out to be useful. For an element $$x\in R$$, we define the adjoint mapping $$\mathrm{ad}_x:R\to R$$ by:
 * $$\operatorname{ad}_x(y) = [x, y] = xy-yx.$$

This mapping is a derivation on the ring R:
 * $$\mathrm{ad}_x\!(yz) \ =\ \mathrm{ad}_x\!(y) \,z \,+\, y\,\mathrm{ad}_x\!(z).$$

By the Jacobi identity, it is also a derivation over the commutation operation:
 * $$\mathrm{ad}_x[y,z] \ =\ [\mathrm{ad}_x\!(y),z] \,+\, [y,\mathrm{ad}_x\!(z)] .$$

Composing such mappings, we get for example $$\operatorname{ad}_x\operatorname{ad}_y(z) = [x, [y, z]\,] $$ and $$\operatorname{ad}_x^2\!(z) \ =\ \operatorname{ad}_x\!(\operatorname{ad}_x\!(z)) \ =\ [x, [x, z]\,].$$ We may consider $$\mathrm{ad}$$ itself as a mapping, $$\mathrm{ad}: R \to \mathrm{End}(R) $$, where $$\mathrm{End}(R)$$ is the ring of mappings from R to itself with composition as the multiplication operation. Then $$\mathrm{ad}$$ is a Lie algebra homomorphism, preserving the commutator:
 * $$\operatorname{ad}_{[x, y]} = \left[ \operatorname{ad}_x, \operatorname{ad}_y \right].$$

By contrast, it is not always a ring homomorphism: usually $$\operatorname{ad}_{xy} \,\neq\, \operatorname{ad}_x\operatorname{ad}_y $$.

General Leibniz rule
The general Leibniz rule, expanding repeated derivatives of a product, can be written abstractly using the adjoint representation:
 * $$x^n y = \sum_{k = 0}^n \binom{n}{k} \operatorname{ad}_x^k\!(y)\, x^{n - k}.$$

Replacing $$x$$ by the differentiation operator $$\partial$$, and $$y$$ by the multiplication operator $$m_f : g \mapsto fg$$, we get $$\operatorname{ad}(\partial)(m_f) = m_{\partial(f)}$$, and applying both sides to a function g, the identity becomes the usual Leibniz rule for the nth derivative $$\partial^{n}\!(fg)$$.

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

title: Commutator


text:
Talk:Commutator

Matrices in bases
What does this statement mean? "In linear algebra, if two matrices commute in one basis they will commute in any basis." It seems to be trying to mean that, if $$A$$ and $$B$$ are the matrices of two linear operators with respect to one basis, and $$A'$$ and $$B'$$ are the matrices of the same two operators (in the same order) with respect to another basis, then $$A$$ and $$B$$ commute if and only if $$A'$$ and $$B'$$ do. However, the statement as it stands is meaningless. JadeNB 21:18, 10 October 2006 (UTC)

Standard notation
The standard mathematical notation for commutator is $$\scriptstyle{ad(x)(y)=[x,y]}$$. As I see no reason to depart from the standard, I changed the relevant paragraph. AlainD 10:02, 25 January 2007 (UTC)

notation for ad(x)ad(x)(y)
I think it's misleading to use the notation "ad(x)^3(y) = [x,[x,[x,y]]]", since there are a lot of different algebras floating around. In particular, ad(x) is a derivation, which has both the usual algebra structure of composition, and a Lie algebra structure induced from the former. Of course y lives in a Lie algebra, where something like y^3 is not defined. I admit that ad(x) may be unambiguous mathematically, but I feel that in this context it's best to avoid confusion if possible. Tesseran 07:46, 28 June 2007 (UTC)

Brief section about the anticommutator
I suggest that we add a brief section or one-liner about the anticommutator: {A,B} := AB + BA since this notation is not mentioned in the anticommutativity article and comes up a lot (at least in physics). Cheers A13ean (talk) 22:50, 5 October 2008 (UTC)
 * Agreed (especially since anticommutator redirects here). I made a quick start, feel free to flesh it out a bit. --Strange but untrue (talk) 17:34, 10 November 2008 (UTC)

Reference needed for uncertainty principle
In the Ring theory section, mention is made of the connection between the commutator, the Heisenberg uncertainty principle and the Robertson-Schrödinger relation. This discussion is clearly from Liboff, I have a copy and I have located the subject matter in the text, but my copy is the 2nd edition, not the 4th edition listed in the References section of the article. Would someone who has access to the 4th edition please update the page number of the reference? — Anita5192 (talk) 05:13, 25 March 2012 (UTC)
 * Nevermind. I just looked up a copy in the library and fixed this myself. — Anita5192 (talk) 04:51, 27 July 2012 (UTC)

Ring commutator
Should Ring commutator redirect here? — Preceding unsigned comment added by 70.247.173.205 (talk) 04:56, 1 March 2016 (UTC)

Ring identities
The section on ring identities is strange and confusing, in that it launches straight into Lie algebra identities, without developing any other results first. Where are the finite rings? Why jump straight to algebras? Maybe this section needs a new heading? Perhaps more identities can be found for these cases? — Preceding unsigned comment added by 70.247.173.205 (talk) 05:00, 1 March 2016 (UTC)

Non-closure?
In the first section under Group Theory, it is stated that "Note that one must consider the subgroup generated by the set of commutators because in general the set of commutators is not closed under the group operation." Why does closure not exist? The operation is a binary operation, the elements chosen come from the group. And in fact, it is a group we are talking about from which commutators are being generated. By definition of a group, we should have closure. 50.35.103.217 (talk) 22:46, 15 September 2017 (UTC)
 * The problem is that in general the product of two commutators need not be a commutator.
 * Let G be a group under a given binary operation ∗. By definition, a non-empty subset H of a group G is a subgroup of G if and only if it is closed under inverses and products, i.e., if the following two statements are true:
 * The inverse a−1 with respect to ∗ of any element a of H is again in H.
 * The product a∗b of any two elements of H is again in H.
 * Now let H be the set of commutators of elements of G. This subset of G is closed under inverses, for [ a, b ] −1 = [ b, a ], and so the inverse of any commutator is again a commutator. However, in general the product of two commutators need not be a commutator. The canonical example is the free group over the four-element set { a, b, c, d } . Here the element [ a, b ] [ c, d ] cannot be written as a commutator. – Tea2min (talk) 18:28, 16 September 2017 (UTC)

Ring Theory Lie Algebra Identities
The third property is redundant because [A + B, C] and [A, A] = 0 imply it. This is according to Abraham and Marsden's Foundations of Mechanics. Should we get rid of property 2 or 3, or put it in under the commutator identities?

MichalKononenko (talk) 05:18, 18 January 2018 (UTC)

Lie-Algebra identities
Property no. 4 in the Lie Algebra identities (https://en.wikipedia.org/wiki/Commutator#Lie-algebra_identities) is either plain wrong and inconsistent with, say, the initial identity under Additional Identities (i.e. [AB,C] = A[B,C]+B[A,C]) or it requires a much better explanation of why and when it holds.

Episanty (talk) 21:07, 18 August 2018 (UTC)

 * I don't know what you are referring to. The identity [AB,C] = A[B,C] + B[A,C] is nowhere in the article, but [A,BC] = [A,B]C + B[A,C] and [AB,C] = A[B,C] + [A,C]B are in the article, and both are correct.—Anita5192 (talk) 00:22, 19 August 2018 (UTC)

 * The identity [AX+BY,Z]=A[X,Z]+B[Y,Z], currently numbered no. 5 at https://en.wikipedia.org/wiki/Commutator#Lie-algebra_identities, is either (a) completely wrong, or at very best (b) out of place and with missing assumptions. As to why it's considered acceptable to remove a flag for attention without getting due clarification first, I'm completely in the dark. Episanty (talk) 18:03, 20 August 2018 (UTC)

 * You were right about number 5. Thank you for pointing this out.  Number 6 was also incorrect.  I have removed them.—Anita5192 (talk) 21:23, 20 August 2018 (UTC)

title: Talk:Commutator


text:
Talk:Chick Publications

new navbox
Hi everyone,

I have created a navbox, Chick Publications Navbox, with the purpose of holding pages related to Chick Publications.

There used to be a category for this. See Categories for discussion/Log/2008 February 19.

--Kevinkor2 (talk) 11:36, 22 June 2010 (UTC)

Porn link removed
One of the links added to the page (Footnote #63) now leads to a porn site - the link hasn't been changed but for some reason it now redirects to the improper page. I have left the URL up, just removed the hotlink; perhaps someone more familiar with the original source can update the URL. 68.146.64.9 (talk) 22:21, 26 March 2011 (UTC)

 * I tried using Internet Archive but it kept timing out. I removed the URL altogether and replaced it with the the actual name of the original site.  I will keep trying to see if I can get a Internet Archive reference we can use but it generally doesn't have much luck with picture heavy sites.--BruceGrubb (talk) 18:25, 24 April 2011 (UTC)

things to be added
There should be a little bit more about factually and objectively verifiably preposterous nonsense in Chick publications, such as IHS standing for Isis-Horus-Set (or whatever it is), etc. Also, some of the tracts (such as "The Death Cookie") have developed a kind of camp status among a decidedly non-pious audience... AnonMoos (talk) 21:11, 7 April 2011 (UTC)
 * The problem here is there are few reliable sources that talk about the details of the tracks and those that do don't go into enough detail.

 * Trick Tracts: The Truth Behind Those Little Comics which points out factual errors in the tracts is borderline and enter the jabberwock has much the same problems.

 * A related problem is that many times there are no reference to any of the claims in the tracks other than scripture and the few times there are (such as Big Daddy) the source is of very poor quality.

 * Many of the tracks are sloppy in their handling of their subject matter (such as There go the Dinosaurs) that anyone with a reasonable reference book can rip the track to shreds just on the grounds of basic logic. In the case of There go the Dinosaurs it is claimed that the flood wiped out most of the plants reducing the amount of oxygen available to the dinosaurs making them lethargic.  The problem is the track either ignores or is ignorant of the fact that not all Dinosaurs were big-- Archaeopteryx discovered in 1861 is about the size of a modern chicken, Velociraptor discovered in 1923 is the size of a small dog,  and Deinonychus discovered in 1931 is roughly man sized.  The whole premise of the track falls about with the smallest bit of actual research.  This is the case with many of the tracks and explains why there is so little in reliable sources against them--any good armchair researcher can tear most of them apart.--BruceGrubb (talk) 06:23, 22 May 2011 (UTC

title: Talk:Chick Publications


text:
Cairn

A cairn is a human-made pile (or stack) of stones raised for a purpose, usually as a marker or as a burial mound. The word cairn comes from the càrn (plural càirn ).

Cairns have been and are used for a broad variety of purposes. In prehistory, they were raised as markers, as memorials and as burial monuments (some of which contained chambers). In the modern era, cairns are often raised as landmarks, especially to mark the summits of mountains. Cairns are also used as trail markers. They vary in size from small stone markers to entire artificial hills, and in complexity from loose conical rock piles to elaborate megalithic structures. Cairns may be painted or otherwise decorated, whether for increased visibility or for religious reasons.

A variant is the inuksuk (plural inuksuit), used by the Inuit and other peoples of the Arctic region of North America.

Europe
The building of cairns for various purposes goes back into prehistory in Eurasia, ranging in size from small rock sculptures to substantial human-made hills of stone (some built on top of larger, natural hills). The latter are often relatively massive Bronze Age or earlier structures which, like kistvaens and dolmens, frequently contain burials; they are comparable to tumuli (kurgans), but of stone construction instead of earthworks. Cairn originally could more broadly refer to various types of hills and natural stone piles, but today is used exclusively of artificial ones.

Ireland and Britain
The word cairn derives from Scots cairn (with the same meaning), in turn from Scottish Gaelic càrn, which is essentially the same as the corresponding words in other native Celtic languages of Britain, Ireland and Brittany, including Welsh carn (and carnedd), Breton karn, Irish carn, and Cornish karn or carn. Cornwall (Kernow) itself may actually be named after the cairns that dot its landscape, such as Cornwall's highest point, Brown Willy Summit Cairn, a 5 m (16 ft) high and 24 m (79 ft) diameter mound atop Brown Willy hill in Bodmin Moor, an area with many ancient cairns. Burial cairns and other megaliths are the subject of a variety of legends and folklore throughout Britain and Ireland. In Scotland, it is traditional to carry a stone up from the bottom of a hill to place on a cairn at its top. In such a fashion, cairns would grow ever larger. An old Scottish Gaelic blessing is Cuiridh mi clach air do chàrn, "I'll put a stone on your cairn". In Highland folklore it is recounted that before Highland clans fought in a battle, each man would place a stone in a pile. Those who survived the battle returned and removed a stone from the pile. The stones that remained were built into a cairn to honour the dead. Cairns in the region were also put to vital practical use. For example, Dún Aonghasa, an all-stone Iron Age Irish hill fort on Inishmore in the Aran Islands, is still surrounded by small cairns and strategically placed jutting rocks, used collectively as an alternative to defensive earthworks because of the karst landscape's lack of soil. In February 2020, ancient cairns dated back to 4,500 year-old used to bury the leaders or chieftains of neolithic tribes people were revealed in the Cwmcelyn in Blaenau Gwent by the Aberystruth Archaeological Society.

Scandinavia and Iceland
In Scandinavia, cairns have been used for centuries as trail and sea marks, among other purposes, the most notable being the Three-Country Cairn. In Iceland, cairns were often used as markers along the numerous single-file roads or paths that crisscrossed the island; many of these ancient cairns are still standing, although the paths have disappeared. In Norse Greenland, cairns were used as a hunting implement, a game-driving "lane", used to direct reindeer towards a game jump.

Greece and the Balkans
In the mythology of ancient Greece, cairns were associated with Hermes, the god of overland travel. According to one legend, Hermes was put on trial by Hera for slaying her favorite servant, the monster Argus. All of the other gods acted as a jury, and as a way of declaring their verdict they were given pebbles, and told to throw them at whichever person they deemed to be in the right, Hermes or Hera. Hermes argued so skillfully that he ended up buried under a heap of pebbles, and this was the first cairn. In Croatia, in areas of ancient Dalmatia, such as Herzegovina and the Krajina, they are known as gromila.

Portugal
In Portugal, a cairn is called a moledro. In a legend the moledros are enchanted soldiers, and if one stone is taken from the pile and put under a pillow, in the morning a soldier will appear for a brief moment, then will change back to a stone and magically return to the pile. The cairns that mark the place where someone died or cover the graves alongside the roads where in the past people were buried are called Fiéis de Deus. The same name given to the stones was given to the dead whose identity was unknown.

North and northeast Africa
Cairns (taalo) are a common feature at El Ayo, Haylan, Qa'ableh, Qombo'ul, Heis, Salweyn and Gelweita, among other places. Somaliland in general is home to a lot of such historical settlements and archaeological sites wherein are found numerous ancient ruins and buildings, many of obscure origins. However, many of these old structures have yet to be properly explored, a process which would help shed further light on local history and facilitate their preservation for posterity.

Since Neolithic times, the climate of North Africa has become drier. A reminder of the desertification of the area is provided by megalithic remains, which occur in a great variety of forms and in vast numbers in presently arid and uninhabitable wastelands: cairns (kerkour), dolmens and circles like Stonehenge, underground cells excavated in rock, barrows topped with huge slabs, and step pyramid-like mounds.

Middle East
The Biblical place name Gilead (mentioned in the Old Testament books of Genesis, Numbers, Judges and elsewhere) means literally 'a heap of testimony (or evidence)' as does its Aramaic translation Yegar Sahaduta. In modern Hebrew, gal-'ed (גל-עד) is the actual word for "cairn". In Genesis 31 the cairn of Gilead was set up as a border demarcation between Jacob and his father-in-law Laban at their last meeting.

Asia and the Pacific
Starting in the Bronze Age, burial cists were sometimes interred into cairns, which would be situated in conspicuous positions, often on the skyline above the village of the deceased. Though most often found in the British Isles, evidence of Bronze Age cists have been found in Mongolia. The stones may have been thought to deter grave robbers and scavengers. Another explanation is that they were to stop the dead from rising. There remains a Jewish tradition of placing small stones on a person's grave as a token of respect, known as visitation stones, though this is generally to relate the longevity of stone to the eternal nature of the soul and is not usually done in a cairn fashion. Stupas in India and Tibet probably started out in a similar fashion, although they now generally contain the ashes of a Buddhist saint or lama.

A traditional and often decorated, heap-formed cairn called an ovoo is made in Mongolia. It primarily serves religious purposes, and finds use in both Tengriist and Buddhist ceremonies. Ovoos were also often used as landmarks and meeting points in traditional nomadic Mongolian culture. Traditional ceremonies still take place at ovoos today, and in a survey conducted, 75 participants out of 144 participants stated that they believe in ovoo ceremonies. However, mining and other industrial operations today threaten the ovoos

In Hawaii, cairns, called by the Hawaiian word ahu, are still being built today. Though in other cultures, the cairns were typically used as trail markers and sometimes funerary sites, the ancient Hawaiians also used them as altars or security towers. The Hawaiian people are still building these cairns today, using them as the focal points for ceremonies honoring their ancestors and spirituality.

In South Korea, cairns are quite prevalent, often found along roadsides and trails, up on mountain peaks, and adjacent to Buddhist temples. Hikers frequently add stones to existing cairns trying to get just one more on top of the pile, to bring good luck. This tradition has its roots in the worship of San-shin, or Mountain Spirit, so often still revered in Korean culture.

The Americas
Throughout what today are the continental United States and Canada, some Indigenous peoples of the Americas have built structures similar to cairns. In some cases, these are general trail markers, and in other cases they mark game-driving "lanes", such as those leading to buffalo jumps.

Peoples from some of the Indigenous cultures of arctic North America (i.e. northern Canada, Alaska and Greenland) have built carefully constructed stone sculptures called inuksuit and inunnguat, which serve as landmarks and directional markers. The oldest of these structures are very old and pre-date contact with Europeans. They are iconic of the region (an inuksuk even features on the flag of the Canadian far-northeastern territory, Nunavut).

Cairns have been used throughout what is now Latin America, since pre-Columbian times, to mark trails. Even today, in the Andes of South America, the Quechuan peoples build cairns as part of their spiritual and religious traditions.

Modern cairns
Cairns can be used to mark hiking trails, especially in mountain regions at or above the tree line. Examples can be seen in the lava fields of Volcanoes National Park to mark several hikes. Placed at regular intervals, a series of cairns can be used to indicate a path across stony or barren terrain, even across glaciers. In Acadia National Park, in Maine, the trails are marked by a special type of cairn instituted in the 1890s by Waldron Bates and dubbed Bates cairns.

Sea cairns
Coastal cairns called sea marks are also common in the northern latitudes, especially in the island-strewn waters of Scandinavia and eastern Canada. They are placed along shores and on islands and islets. Usually painted white for improved offshore visibility, they serve as navigation aids. In Sweden, they are called kummel, in Finland kummeli, in Norway varde, and are indicated in navigation charts and maintained as part of the nautical marking system.

Other types

 * Chambered cairn
 * Clava cairn
 * Clearance cairn
 * Court cairn
 * Pyramid
 * Ring cairn
 * Stupa
 * Tumulus
 * Unchambered long cairn

title: Cairn


text:
Characteristic subgroup

In mathematics, particularly in the area of abstract algebra known as group theory, a characteristic subgroup is a subgroup that is mapped to itself by every automorphism of the parent group. Because every conjugation map is an inner automorphism, every characteristic subgroup is normal; though the converse is not guaranteed. Examples of characteristic subgroups include the commutator subgroup and the center of a group.

Definition
A subgroup $H$ of a group $G$ is called a characteristic subgroup if for every automorphism $φ$ of $G$, one has $φ(H) ≤ H$; then write $H char G$.

It would be equivalent to require the stronger condition $φ(H)$ = $H$ for every automorphism $φ$ of $G$, because $φ^{−1}(H) ≤ H$ implies the reverse inclusion $H ≤ φ(H)$.

Basic properties
Given $H char G$, every automorphism of $G$ induces an automorphism of the quotient group $G/H$, which yields a homomorphism $Aut(G) → Aut(G/H)$.

If $G$ has a unique subgroup $H$ of a given index, then $H$ is characteristic in $G$.

Normal subgroup
A subgroup of $H$ that is invariant under all inner automorphisms is called normal; also, an invariant subgroup.

Since $∀φ ∈ Inn(G)： φ[H] ≤ H$ and a characteristic subgroup is invariant under all automorphisms, every characteristic subgroup is normal. However, not every normal subgroup is characteristic. Here are several examples:
 * Let $Inn(G) ⊆ Aut(G)$ be a nontrivial group, and let $H$ be the direct product, $G$. Then the subgroups, $H × H$ and H  × {1$)$}}, are both normal, but neither is characteristic.  In particular, neither of these subgroups is invariant under the automorphism, ${1} × H$, that switches the two factors.
 * For a concrete example of this, let $(x, y) → (y, x)$ be the Klein four-group (which is isomorphic to the direct product, $$\mathbb{Z}_2 \times \mathbb{Z}_2$$). Since this group is abelian, every subgroup is normal; but every permutation of the 3 non-identity elements is an automorphism of $V$, so the 3 subgroups of order 2 are not characteristic.  Here $V$. Consider H = {e, a}}} and consider the automorphism, $V = {e, a, b, ab}$; then $T(e) = e, T(a) = b, T(b) = a, T(ab) = ab$ is not contained in $T(H)$.
 * In the quaternion group of order 8, each of the cyclic subgroups of order 4 is normal, but none of these are characteristic. However, the subgroup, {1, −1}}}, is characteristic, since it is the only subgroup of order 2.
 * If $H$ is even, the dihedral group of order $n$ has 3 subgroups of index 2, all of which are normal. One of these is the cyclic subgroup, which is characteristic.  The other two subgroups are dihedral; these are permuted by an outer automorphism of the parent group, and are therefore not characteristic.

Strictly characteristic subgroup
A strictly characteristic subgroup, or a distinguished subgroup, which is invariant under surjective endomorphisms. For finite groups, surjectivity of an endomorphism implies injectivity, so a surjective endomorphism is an automorphism; thus being strictly characteristic is equivalent to characteristic. This is not the case anymore for infinite groups.

Fully characteristic subgroup
For an even stronger constraint, a fully characteristic subgroup (also, fully invariant subgroup; cf. invariant subgroup), $2n$, of a group $H$, is a group remaining invariant under every endomorphism of $G$; that is,

Every group has itself (the improper subgroup) and the trivial subgroup as two of its fully characteristic subgroups. The commutator subgroup of a group is always a fully characteristic subgroup.

Every endomorphism of $G$ induces an endomorphism of $∀φ ∈ End(G)： φ[H] ≤ H$, which yields a map $G$.

Verbal subgroup
An even stronger constraint is verbal subgroup, which is the image of a fully invariant subgroup of a free group under a homomorphism. More generally, any verbal subgroup is always fully characteristic. For any reduced free group, and, in particular, for any free group, the converse also holds: every fully characteristic subgroup is verbal.

Transitivity
The property of being characteristic or fully characteristic is transitive; if $G/H$ is a (fully) characteristic subgroup of $End(G) → End(G/H)$, and $H$ is a (fully) characteristic subgroup of $K$, then $K$ is a (fully) characteristic subgroup of $G$.

Moreover, while normality is not transitive, it is true that every characteristic subgroup of a normal subgroup is normal.

Similarly, while being strictly characteristic (distinguished) is not transitive, it is true that every fully characteristic subgroup of a strictly characteristic subgroup is strictly characteristic.

However, unlike normality, if $H$ and $G$ is a subgroup of $H char K char G ⇒ H char G$ containing $H char K ⊲ G ⇒ H ⊲ G$, then in general $H char G$ is not necessarily characteristic in $K$.

Containments
Every subgroup that is fully characteristic is certainly strictly characteristic and characteristic; but a characteristic or even strictly characteristic subgroup need not be fully characteristic.

The center of a group is always a strictly characteristic subgroup, but it is not always fully characteristic. For example, the finite group of order 12, $G$, has a homomorphism taking $H$ to $H$, which takes the center, $$1 \times \mathbb{Z} / 2 \mathbb{Z}$$, into a subgroup of $K$, which meets the center only in the identity.

The relationship amongst these subgroup properties can be expressed as:
 * Subgroup ⇐ Normal subgroup ⇐ Characteristic subgroup ⇐ Strictly characteristic subgroup ⇐ Fully characteristic subgroup ⇐ Verbal subgroup

Finite example
Consider the group $H char G, H < K < G ⇏ H char K$ (the group of order 12 that is the direct product of the symmetric group of order 6 and a cyclic group of order 2). The center of $Sym(3) × $\mathbb{Z} / 2 \mathbb{Z}$$ is isomorphic to its second factor $$\mathbb{Z}_2$$. Note that the first factor, $(π, y)$, contains subgroups isomorphic to $$\mathbb{Z}_2$$, for instance $((1, 2)y, 0)$; let $$f: \mathbb{Z}_2<\rarr \text{S}_3$$ be the morphism mapping $$\mathbb{Z}_2$$ onto the indicated subgroup. Then the composition of the projection of $Sym(3) × 1$ onto its second factor $$\mathbb{Z}_2$$, followed by $G = S3 × $\mathbb{Z}_2$$, followed by the inclusion of $G$ into $S3$ as its first factor, provides an endomorphism of ${e, (12)}$ under which the image of the center, $$\mathbb{Z}_2$$, is not contained in the center, so here the center is not a fully characteristic subgroup of $G$.

Cyclic groups
Every subgroup of a cyclic group is characteristic.

Subgroup functors
The derived subgroup (or commutator subgroup) of a group is a verbal subgroup. The torsion subgroup of an abelian group is a fully invariant subgroup.

Topological groups
The identity component of a topological group is always a characteristic subgroup.

title: Characteristic subgroup


text:
List of cat breeds

The following list of cat breeds includes only domestic cat breeds and domestic and wild hybrids. The list includes established breeds recognized by various cat registries, new and experimental breeds, landraces being established as standardized breeds, distinct domestic populations not being actively developed and lapsed (extinct) breeds.

As of 2023, The International Cat Association (TICA) recognizes 73 standardized breeds, the Cat Fanciers' Association (CFA) recognizes 45, the Fédération Internationale Féline (FIFe) recognizes 50, the Governing Council of the Cat Fancy (GCCF) recognizes 45, and the World Cat Federation (WCF) recognizes 69.

Inconsistency in a breed's classification and naming among registries means that an individual animal may be considered different breeds by different registries (though not necessarily eligible for registry in them all, depending on its exact ancestry). For example, TICA's Himalayan is considered a colorpoint variety of the Persian by the CFA, while the Javanese (or Colorpoint Longhair) is a color variation of the Balinese in both the TICA and the CFA; both breeds are merged (along with the Colorpoint Shorthair) into a single "mega-breed", the Colourpoint, by the World Cat Federation (WCF), who have repurposed the name "Javanese" for the Oriental Longhair. Also, "Colo[u]rpoint Longhair" refers to different breeds in other registries. There are many examples of nomenclatural overlap and differences of this sort. Furthermore, many geographical and cultural names for cat breeds are fanciful selections made by Western breeders to be exotic sounding and bear no relationship to the actual origin of the breeds; the Balinese, Javanese, and Himalayan are all examples of this trend.

The domestic short-haired and domestic long-haired cat types are not breeds, but terms used (with various spellings) in the cat fancy to describe "mongrel" or "bicolor" cats by coat length, ones that do not belong to a particular breed. Some registries such as the Cat Fanciers' Association allow for domestic short hairs and domestic long hairs to be registered for the purpose of outcrossing. They should not be confused with standardized breeds with similar names, such as the British Shorthair and Oriental Longhair.

title: List of cat breeds