Talk:Nullity

The info in this article is contained in Null space
This definition of nullity (for matrices) makes the rank-nullity theorem true by definition. Isn't there a definition for matrices that avoids this?

Yes there is. I'm going to copy the definition of nullity out of my Linear Algebra textbook and see what I can do to expand on it/explain it. Since it's a definition, hopefully this won't be construed as a copywrite violation. Fieari 15:51, 16 May 2005 (UTC)
 * Actually, I just checked and it seems to me that all the information about nullity can be found in Null space. Perhaps nullity should simply redirect there?  I don't know enough about wikipedia to know how to go about making such a redirect, or who to ask that can make it happen. Fieari 16:02, 16 May 2005 (UTC)


 * Agree. I will make this a redirect now. Oleg Alexandrov 17:53, 16 May 2005 (UTC)

Division By Zero
What about Dr. James Anderson's new nullity number? I just read about it on the BBC website: http://www.bbc.co.uk/berkshire/content/articles/2006/12/06/divide_zero_feature.shtml --breun 11:33, 7 December 2006 (UTC)


 * Outside of the BBC article (and the accompanying Slashdot article), I've never heard of it before. The linear algebra definition, on the other hand, is well known and an important concept when dealing with matrices. I'm not opposed to seeing an article about it, but as of a few minutes ago, there was almost no useful information about this new definition of nullity, certainly not enough to justify removing the redirect to Null space. Plus it was in violation of WP:NPOV. For now, I've reverted the page to the redirect-only version. --Tjohns  &#9998; 11:41, 7 December 2006 (UTC)


 * Outside of the BBC article (...) I've never heard of it before.  -- Yes, that's why it's on BBC News as an invention. I think we should put a disambig here, at least. It is also on the wire, and at least Aftenposten and Verdens Gang has printed it... toresbe 12:29, 7 December 2006 (UTC)


 * Like I said, I have no problem with content on this as long as it's objective and the link to Null space remains. If you take a look at the edit history, so far everything that's been contributed fails both those criteria. A disambig would be just fine with me. --Tjohns  &#9998; 12:34, 7 December 2006 (UTC)


 * Perhaps we need to recreate the category Category:Pseudomathematics to cover it. As it stands, it's a Neologism which BBC "news" chose to cover.  (The next step is a lawsuit by his students against him for education fraud?)  That would be notable. &mdash; Arthur Rubin |  (talk) 13:39, 7 December 2006 (UTC)


 * Inventions in mathematics are usually just bull. Discoveries are something that should be noted, if someone inventes a new notation for the number one it should hardly be noted. But as someone pointed out, this is more than just a new notation. Someone should read the papers he released. But I think the papers are mostly rubbish. But IANAM --Soyweiser 15:17, 7 December 2006 (UTC)

It doesn't seem obviously wrong to put Dr. Anderson's research here. BBC News is a secondary source and Dr. Anderson's paper is a primary source, so it's not like this would open the floodgates to original research/neologisms. If there are credible sources that cast doubt on the research, they should go in the article, the better to inform the world. This is especially true today while the story is on the wires and people are going to be looking for the article all day and trying to create it if it isn't here. It's hardly the end of the world if it sits around being imperfect for a few days -- and definitely less of a waste of time than continuing to knock it down over and over.

At the least, we should make the redirect go to division by zero. No articles currently link to the linear algebraic definition, and that article will just confuse people who are looking for more information about Dr. Anderson's research (and we certainly don't want them to put it in that article). I suspect a great many of these are looking for a less credulous take on it than the BBC presented... that's how I got here anyway. Eliot 14:07, 7 December 2006 (UTC)


 * It's not WikiNews, it's Wikipedia. And part of the problem is that there are no WP:RS other than (possibly) BBC news itself as to the content of the material.  We're probably not going to see a formal refutation because it's not notable enough.  All I can say for certain is that if an article on Dr. Anderson's research appears in Wikipedia in Category:Mathematics, it should be speedily deleted as db-nonsense in the context of mathematics.  If there is an article on the concept (possibly under Dr. Anderson's name), a redirect tag in Null space might be appropriate.  &mdash; Arthur Rubin |  (talk) 14:15, 7 December 2006 (UTC)


 * There is absolutely no reason to redirect the article to null space right now, since thousands of people are going to hit the page today looking for information on division by zero, and nobody is going to hit the page looking for information on linear algebra. Sure, you believe BBC shouldn't have promulgated the neologism, and you're probably right about that. But the fact of the matter is, they did, and so people are coming to this article looking for informstion. Refusing to let the article direct them to the information they're after is just silly. There is some good information on the division by zero article that is relevant to Dr. Anderson's claims, by the way, so I think we should leave it as a redirect to that article for now. Someday when somebody writes an article that links to nullity as a linear algebra concept, the neologism will be forgotten and there will be a good reason to put it back. (Note that I wouldn't be saying this if nullity were actually the article about the linear algebra concept, but since it's not at all a common term for that concept, it's different.) Eliot 14:24, 7 December 2006 (UTC)


 * That's three reverts on this page today, Arthur, so it's time to find something else to do. Eliot 14:34, 7 December 2006 (UTC)


 * It's also a redirect against concensus. You could easily be blocked for that, although not by me.  &mdash; Arthur Rubin |  (talk) 14:36, 7 December 2006 (UTC)


 * Nullity should not, under any circumstances, be a redirect directly to Division by zero. Not only is that wrong, it's misleading. It doesn't matter how many people come here, false information is false information.


 * However, I will say that there is some argument to be made for having a disambiguation page. As I said over in Talk:Null space, Wikipedia is not the place to debate whether a theory is correct or not. Anderson has published his ideas in an acacemic journal (see and ), so it's not WP:OR. --Tjohns   &#9998; 14:50, 7 December 2006 (UTC)

There is now a proper redirect page pointing towards both concepts. If you wish to write about Anderson's nullity, please do so over at Divide by zero. --Tjohns  &#9998; 15:10, 7 December 2006 (UTC)
 * ...It's a year and a half later, and the only thing about it still on that page is a mention of a Wikinews article on the subject. --Short Circuit (talk) 22:49, 21 May 2008 (UTC)

Sorry to jump into a hot fire here. I saw the article on the BBC website. I think lots of people will be coming here from there, and I think the article as it stands now accurately describes the situation. It seems pretty clear to me (as a brand new editor to this article) that Nullity is an established term in mathematics regarding Null space, and professor Anderson has just coined the term to mean something else. This page, as it stands now, provides correct information about this to users, and appropriate redirects. I just thought that if someone created the disambig page tastefully, that it would stick and encourage constructive contributions. Vir4030 15:14, 7 December 2006 (UTC)

Disambiguation
Now that it's a disambiguation page, can we delete the line pointing to division by zero, as it's pointed to in the next line (nullity (Transreal)). &mdash; Arthur Rubin | (talk) 15:24, 7 December 2006 (UTC)


 * Done. --Tjohns  &#9998; 15:32, 7 December 2006 (UTC)

Established?
Although I don't think it matters much, I'm not sure 'non-established' is an accurate description of transreal numbers -- doesn't the axiomatization and associated proofs more or less establish the system? I definitely agree that there should be some disclaimer on the link, but 'unadopted' or 'barely formalized' don't sound good. Is there a formally distinction between established and non-established math concepts that I'm not aware of? I'm mostly just curious and don't plan to change it. Eliot 17:45, 7 December 2006 (UTC)
 * What other synonyms are there for "neologism" in mathematics? That's what I was looking for.  &mdash; Arthur Rubin |  (talk) 17:48, 7 December 2006 (UTC)
 * Amen to Arthur Rubin. Chutzpan 02:41, 27 March 2007 (UTC)

Dr. Anderson's nullity and the BBC
Right now, the BBC's article page for that invention says that there will be more debate on the subject. Many of the viewers' comments (in fact, most of the ones not signed by Chuck Norris et al) seemed to have disproved Dr. Anderson's theory as axiomatically invalid. And many indicate that this is just a rename of NaN (not a number). Should we also link there? Louis 13:53, 8 December 2006 (UTC)


 * from the same page as the article "Given the, er, light-hearted mathematical debate Dr Anderson's theory has generated, we're delighted to announce he will join us on Tuesday 12 December to answer questions and discuss some of the criticisms levelled against his theory of 'nullity'. You will be able to hear in more detail from Dr Anderson on this page later on Tuesday." --212.183.136.193 15:54, 9 December 2006 (UTC)


 * Even though I think Dr. Anderson's nullity idea is total nonsense, I think it should be represented in the article since wikipedia is a neutral representation of data... but it's just a theory and it should be stated as such —Preceding unsigned comment added by Agreene175 (talk • contribs) 16:45, December 10, 2006


 * It's not even a theory (at least as presented here). It's a definition.  My understanding of WP:NEO is that a definition remains a neologism until someone else uses it, other than in the context "Dr. Anderson calls this nullity".  &mdash; Arthur Rubin |  (talk) 16:54, 10 December 2006 (UTC)

Maybe we should have this wikinews link box appearing somewhere here -- Nojer2 18:00, 21 December 2006 (UTC) 

Seeing that links to Anderson's page have been repeatedly added and deleted since 2006, I'd like to add the Wikinews box as Nojer2 suggested... any objections?

The merits of his "nullity" "invention" notwithstanding, it's a safe bet that there are at least some people coming to Wikipedia looking for "nullity" in relation to Anderson after having seen a reference to it elsewhere. (Google "solve division by zero" or similar and the BBC article comes up near the top.) We ought to help these users find what they're looking for, and the Wikinews article does a decent job of explaining the significance of his "solution." 28bytes (talk) 06:31, 7 July 2010 (UTC)

Not "in mathematics"
I'm uncomfortable with having Richard Anderson's "nullity" under the heading "in mathematics". Presented as a mathematical concept, his transreal numbers are unsupported original research. There are no reliable sources for the math, but there are reliable sources for the media reaction to James Anderson, so I think the disambiguation should point to his article.

The typical misinformed math student who shows up here might not be able to look at "null space" and "transreal numbers" and figure out which one involves dividing 0 by 0, so I think clarification is necessary.

I don't hold a neutral POV here, so I won't go right ahead and make the change, but how about this for the disambiguation?

Nullity may refer to:
 * Nullity (conflict), a legal declaration that no marriage had ever come into being
 * The nullity of a mathematical operator, which is the dimension of its null space
 * Nullity, a non-established mathematical concept that James Anderson (computer scientist) claims to enable division by zero

 r speer  / ɹəəds ɹ  18:20, 13 December 2006 (UTC)


 * That looks fine to me. I'm going to go ahead and add it. -- S onicChao talk 16:03, 16 December 2006 (UTC)
 * Already been done by someone else. -- S onicChao talk 16:05, 16 December 2006 (UTC)
 * I don't see that in the history. Anyway, I've put in this version (but also included the word "controversial", which was added to the previous version of the page), because transreal numbers is now just a redirect to NaN. And the disambiguation of "Nullity" shouldn't point to "NaN", because that satisfies no one: those who want accuracy would object that NaN is an established concept and Nullity isn't, and James Anderson would object adamantly that Nullity is not NaN.  r speer  / ɹəəds ɹ  22:57, 16 December 2006 (UTC)
 * Well, I have no objection to the change, but if you look closely at the version you replaced, "transreal numbers" linked to a section of Dr. Anderson's article. &mdash; Arthur Rubin | (talk) 20:36, 17 December 2006 (UTC)


 * They can't be "supported" because there is nothing to "support" them, they are definitions (albeit useless ones, at least in my view), not hypotheses and definitions cannot be "supported". Also, "controversial" is too light a word -- NO serious mathematician takes "nullity" (as in this proposed "number" not as in the real mathematical meaning of nullity) seriously, so how much controversy is there anyway? mike4ty4 08:30, 17 May 2007 (UTC)