tea.mathoverflow.net - Discussion Feed (Extending from a plane in R^3, again, and again, and again)

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (22784)

Will Jagy — Tue, 21 Oct 2014 11:48:40 -0700

October 2014. Suvrit says the main question has been settled by Audenaert, see http://arxiv.org/abs/1410.4941 and http://mathoverflow.net/questions/87872/ratio-sum-comparison-on-operators/87961#comment462204_87961

I see, later in his answer, Suvrit points out that an earlier arXiv preprint he had found turned out to be wrong, along with addressing only part of the problem. The reason for optimism this time is the stature of the person posting the preprint.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (20069)

Will Jagy — Thu, 06 Sep 2012 12:08:35 -0700

Suvrit has pointed out a new arXiv item with an apparent resolution of the main conjecture at the heart of this.

http://mathoverflow.net/questions/87872/ratio-sum-comparison-on-operators/87961#87961

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18613)

Will Jagy — Mon, 05 Mar 2012 11:39:46 -0800

Darij and Yemon, the idea I had was putting screen-capture jpegs of the dozen questions I have, or more if I find them, on a page on my website, readily available and searchable. Also put some keywords so it comes up when people search the topic. The trouble is that the power supply on the host computer ("zakuski") died, and the friend in charge of that computer has big problems and time commitment problems with his parents being ill. So there is a question about where to post anything. Anyway, this is the reason for the request in http://tea.mathoverflow.net/discussion/1318/i-cant-see-my-toes, with title being an homage to http://tea.mathoverflow.net/discussion/1317/i-cant-see-my-userpage. If I had a list of the last 500 self-deleted questions, by five-digit number, I could fill in some gaps in the timeline.

Actually, self-deleted posts probably far outnumber other deleted posts.

Alright, Anton has been posting lists at http://tea.mathoverflow.net/discussion/792/1/deleted-questions-with-possibly-substantive-answers/ with the additional condition that at least one answer was posted.

There is also a list of everything deleted, ordered by day/time of deletion rather than day of asking, under Tools//Links//Recently_Deleted_Posts with some 400 pages, but does include question title and other info, and each entry is a link to the deleted question. So I should be able to do this on my own, it will just take some weeks, which is fine.

darijgrinberg comments on "Extending from a plane in R^3, again, and again, and again" (18612)

darijgrinberg — Mon, 05 Mar 2012 09:28:52 -0800

I was just trying to be sarcastic.

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (18608)

Yemon Choi — Mon, 05 Mar 2012 00:22:40 -0800

Darij, I thought crowdsourcing could be done transparently, without subterfuge? Or is this one of these "get off my lawn you varmints" moments that I seem to be having with increasing frequency?

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18594)

Will Jagy — Sat, 03 Mar 2012 22:19:21 -0800

darij, I don't know the word crowdsource but can guess. Note that MSE question 115903, identical, was also self-deleted after I put a link to here. Nothing much to be done but whack-a-mole. After some of Suvrit's recent answers it seems likely that this is one or more faculty members somewhere. I knew what to do when I thought it was student(s).

darijgrinberg comments on "Extending from a plane in R^3, again, and again, and again" (18593)

darijgrinberg — Sat, 03 Mar 2012 22:01:57 -0800

Somebody is trying to crowdsource solving an open problem?

Looks like a totally reasonable plan to me.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18592)

Will Jagy — Sat, 03 Mar 2012 21:24:15 -0800

http://mathoverflow.net/questions/90181/eigenvalues-and-orthogonal-matrix-question

See Suvrit's answer: http://mathoverflow.net/questions/87872/ratio-sum-comparison-on-operators/87961#87961

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18549)

Will Jagy — Tue, 21 Feb 2012 13:05:30 -0800

darij, they might, the guy sometimes waits for a while before self-deleting his questions. Not always. I am especially proud of question 80108. Posted on November 3, 2011 at 3:33. At 3:35 I put a comment "You have got to be kidding." He deleted the question at 3:38.

darijgrinberg comments on "Extending from a plane in R^3, again, and again, and again" (18546)

darijgrinberg — Tue, 21 Feb 2012 08:33:23 -0800

Well, the non-deleted ones have substantial stuff in their answers, so they should stay so.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18542)

Will Jagy — Mon, 20 Feb 2012 23:30:19 -0800

I finally made it into the MOfia. I went through the jpegs I had, it seems to me that these questions are the same idiot, some are not deleted yet. The common themes are matrices and inequalities. 50600, 76394, 76593, 77058, 79739, 79804, 80108, 81688, 84425, 84473, 87189, 87872,
88495. The one with Suvrit's mention of the Audenaert and Kittaneh paper with matrix conjectures is 87872. I am a little disappointed, knowing the id number for a sock puppet is not that helpful. As a result, I can say I am missing many between 50600 and 76394, unless the idiot was in jail. Without internet access.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18540)

Will Jagy — Sat, 18 Feb 2012 21:46:29 -0800

Delightful as always, edit to http://mathoverflow.net/questions/84425/on-an-eigenvalue-inequality half an hour ago. This is the one where Suvrit gave a counterexample on December 28.

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (18477)

Yemon Choi — Wed, 15 Feb 2012 00:24:31 -0800

As this seems to have become the thread for Will and me to note occurrences of unmotivated matrix analysis, even ones that aren't from the original miscreant(s), here's one which seems reluctant to either state motivation or demonstrate previous work. Noted here in case it gets deleted.

In all seriousness, do these people think that fuller questions will allow unscrupulous MO-frequenting birds of prey to swoop down and steal the prize? Do they fear that admitting this is something they have been asked to do and can't do will invite a hail of snobbish ridicule? Or have they just never been encouraged to ask questions in a helpful way?

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (18347)

Will Jagy — Wed, 08 Feb 2012 21:23:27 -0800

Suvrit noticed this one and gave an answer with some background, http://mathoverflow.net/questions/87872/ratio-sum-comparison-on-operators and Yemon left some comments.

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (18255)

Yemon Choi — Tue, 31 Jan 2012 22:01:20 -0800

This does not seem like the same person (the writing style is somewhat different, as is the willingness to engage in comments) but it does seem strange that this vice of unmotivated matrix questions by anonymous users only ever happens in real 3-dimensional space. Is there some optimization problem, perhaps with a geometric or mechanical interpretation, that I am missing?

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (17987)

Yemon Choi — Sun, 08 Jan 2012 00:29:49 -0800

Looks like it has returned or at least spawned an imitator. If it's not the same person (can anyone run an IP check?) then it's the same bad manners.

Also cross-posted verbatim to MSE without acknowledgment.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (17951)

Will Jagy — Wed, 28 Dec 2011 22:22:49 -0800

It's back, with the item I call question 2, http://mathoverflow.net/questions/84425/on-an-eigenvalue-inequality and http://mathoverflow.net/questions/84473/on-an-eigenvalue-inequality I emailed Suvrit to suggest he not waste any more time on this. Also Igor.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16861)

Will Jagy — Fri, 04 Nov 2011 21:11:33 -0700

Scott, I forwarded you two emails from March 2009. What I would do (have done) is identify, as well as possible, the department, any relevant faculty, and relevant IT people, and ask who might be trying to get an answer for over a year to this question. If this activity is of no concern to anyone there, that's life. I know that Anton has stated that it is not our responsibility to weed out cheaters, but this particular one is really annoying.

I admit it was the IT guy who answered me, possibly through hurt pride over his computers being misused.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16860)

Will Jagy — Fri, 04 Nov 2011 20:46:05 -0700

Of course, the identical crap was posted for a few seconds as question 80108.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16859)

Will Jagy — Fri, 04 Nov 2011 16:55:42 -0700

There is a follow-up over on MSE which is what we want to happen, http://math.stackexchange.com/questions/79076/a-question-on-linear-transformation-ii

although still just the shrill claims that it is not homework and the OP has checked many cases, dubious...

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16857)

Will Jagy — Thu, 03 Nov 2011 21:57:42 -0700

Well, I contacted the university in question when a student tried to get me to help cheat. They were definitely interested, and the head of IT there is the one who identified the miscreant. As far as I can tell there was just a slap on the wrist, as the same things happened a year later. So that is one thing to keep in mind, mathematics departments do not go nuclear over this. If you want the story let me know...

Scott Morrison comments on "Extending from a plane in R^3, again, and again, and again" (16856)

Scott Morrison — Thu, 03 Nov 2011 20:13:31 -0700

Digging through the logs, I have a not-very-well-supported guess as to which university this might be coming from, but still can't think of anything useful to do.

Mariano comments on "Extending from a plane in R^3, again, and again, and again" (16854)

Mariano — Thu, 03 Nov 2011 18:47:06 -0700

That's even worse... it implies there are many people who think this is a sensible behaviour!

Joel Reyes Noche comments on "Extending from a plane in R^3, again, and again, and again" (16853)

Joel Reyes Noche — Thu, 03 Nov 2011 17:45:35 -0700

It's possible that the questions are homework questions of a certain class, the different identities correspond to different students of that class, and they delete the questions after they get the answers so that their classmates or their instructor won't see the questions or the answers.

Mariano comments on "Extending from a plane in R^3, again, and again, and again" (16832)

Mariano — Thu, 03 Nov 2011 03:52:59 -0700

How extraordinarily annoying :/

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16830)

Will Jagy — Wed, 02 Nov 2011 23:40:09 -0700

Add identities

http://mathoverflow.net/users/11757/q-g

http://mathoverflow.net/users/18947/18

http://mathoverflow.net/users/18955/g1

and questions

http://mathoverflow.net/questions/76394/a-singular-value-inequality (deleted)

http://mathoverflow.net/questions/79804/an-inequality-on-matrices

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16810)

Will Jagy — Tue, 01 Nov 2011 16:56:36 -0700

Once I settled on enthusiasm, I ran low on options. Yemon's is better. I like the 8884/9994 syllable scheme. An initial exclamation, then a more thoughtful comment.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16809)

Will Jagy — Tue, 01 Nov 2011 15:09:41 -0700

We bow to your enthusiasm,

Retreat from bound'ry of the chasm

Of despair. Forth to orgasm.

EEjitocide.

Bill Johnson comments on "Extending from a plane in R^3, again, and again, and again" (16808)

Bill Johnson — Tue, 01 Nov 2011 14:54:18 -0700

@Yemon: :)

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (16807)

Yemon Choi — Tue, 01 Nov 2011 14:25:50 -0700

Oh frabjous day! Callooh! Callay!

"He'll pester once again", you say;

I guess you're right, but let dismay

Be put aside.

Perhaps this eejit's urge is sated?

We may not have communicated

Why hit-and-run is rude, and grated;

At least we tried.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16804)

Will Jagy — Tue, 01 Nov 2011 13:39:20 -0700

Posted at http://math.stackexchange.com/questions/77903/a-question-on-linear-transformation some three hours ago, correction edited in an hour later, and an answer supplied! A miracle! Sacre Bleu! Ave Maria! Oy Vey! Praise Allah! For the Lord God omnipotent reigneth, Hallelujah!

Actually, this idiot has gotten pretty good answers on MSE for other questions, late undergraduate homework, under other ID's. So this will likely not end the matter. I got carried away.

Scott Morrison comments on "Extending from a plane in R^3, again, and again, and again" (16801)

Scott Morrison — Tue, 01 Nov 2011 13:09:50 -0700

So what can we do about this? I'm stumped, but appreciate that it's tedious.

Philip Brooker comments on "Extending from a plane in R^3, again, and again, and again" (16798)

Philip Brooker — Tue, 01 Nov 2011 11:21:04 -0700

Another one: http://mathoverflow.net/questions/79739/

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (16731)

Yemon Choi — Fri, 28 Oct 2011 00:15:40 -0700

Will: got it.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16730)

Will Jagy — Fri, 28 Oct 2011 00:14:45 -0700

Yemon, I emailed you two jpegs.

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (16729)

Yemon Choi — Thu, 27 Oct 2011 23:58:18 -0700

Will, I don't think users q.g. nor ksj03 is relevant to the present discussion. The people/person I'm thinking of only ever seems to ask the same question.

MO: 50600 is the ur-example, I have a vague recollection of other variants where 3 gets replaced by some other exponent.

The annoying thing is: I think it could be a mildly interesting question (although norm-preserving extensions usually don't exist unless the range is at least a curly-L-infinity space). But the manner in which these questions are asked, by someone changing their name all the effing time, who not once has attempted to show what he or she has already done towards solving the question, ca me fache.

theo_b comments on "Extending from a plane in R^3, again, and again, and again" (16728)

theo_b — Thu, 27 Oct 2011 22:50:49 -0700

I'm just posting a few links to threads on MO and math.SE: For lack of reputation here I can't check whether the links to two of the three MO-threads work, but I'm pretty certain they do.

MO: 79289 (deleted)
MO: 50600
MO: 52976 (deleted)

math.SE threads:

(the last one is a bit exceptional, but I'm sure it was also posted on MO in various versions).

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16727)

Will Jagy — Thu, 27 Oct 2011 22:49:26 -0700

Questions 76593, 77058 are two I have saved as screen captures (jpegs), earlier identities
http://mathoverflow.net/users/11757/q-g
http://mathoverflow.net/users/17597/ks

http://mathoverflow.net/users/18144/ksj03
http://mathoverflow.net/users/18184/ksj03

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (16726)

Yemon Choi — Thu, 27 Oct 2011 22:09:00 -0700

The questions are always tagged with functional-analysis and operator-norms; they are always about having a 2-dim subspace of R^3 and asking about the relation between l^p to l^p norms of some operator. I would love to give more detail, but the questions keep getting deleted and then reposted without links back to the original, so I can't refresh my memory. Recent variants mentioned Kolmogorov numbers...

Scott Morrison comments on "Extending from a plane in R^3, again, and again, and again" (16725)

Scott Morrison — Thu, 27 Oct 2011 21:40:34 -0700

Could someone who can see deleted posts, and know what's being referred to, post a link or two here? On a cursory glance I couldn't work out what this was referring to.

Will Jagy comments on "Extending from a plane in R^3, again, and again, and again" (16724)

Will Jagy — Thu, 27 Oct 2011 20:21:01 -0700

Hi, Yemon. Same guy, surely.

Yemon Choi comments on "Extending from a plane in R^3, again, and again, and again" (16720)

Yemon Choi — Thu, 27 Oct 2011 17:47:22 -0700

The same mildly interesting question, or minor variants thereof, has been asked several times, often by accounts with different or changing usernames. Each time someone asks for clarification, or points out that the question is similar to or identical to one before, the question gets deleted. This means that even if I were to later spend some spare time trying to answer the question, I have no incentive to, because the user(s) keep employing these monumentally irritating hit-and-run tactics.

Since I can't see deleted questions, I can't give links; but I assume I'm not the only one who's recognized the pattern.