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Unusual discussions there: On the surface of the sphere, if two points are moving east, are their trajectories not parallel?. I have voted to close, but maybe moderators should take a look.

(I am biased though; the Stirling answeras of 2018-07-04 is mine,)

This combinatorics question and that one are so similar (both use the same example and do not separate out the alphabet size as additional parameter $m$ in the question, and the answers do use $m$ but mostly fail to recognize the Stirling number relevance) that they could be merged. Presently I have flagged the older one as a duplicate (because it does not have the Stirling answer).

I have posted that request on Meta.SE because it would need implementation. If they reject it there, it does not matter if it is liked here, and we have to work with what is given. Those queues perhaps. Or reducing the close vote threshold. But I wanted to have made the proposal at least, so that it can receive feedback. (And the feedback is interesting indeed.)

I have made a feature request on Meta.SE: block early answers. You might want to take a look to see if it actually matches what is needed here.

That Q has received a substandard comment and answer already, so I thought pointing to a better thread would help. It has. The answer has been deleted by now.

Closing as duplicate would benefit this thread.

@amWhy Let's hope that we get better tools then. Maybe some form of linguistic analysis, or neural networks... DARPA wants such tools as well.

@amWhy Indeed, that would be a big improvement. ;-D Yet an unnerving one. I am afraid that it is indeed possible for an algorithm to imitate the incongruence displayed by some undoubtedly human low-quality questions here. That is disturbing.

There is an MO question by the same user, and it looks similarly garbled (to me). For a machine, that would be a nice work of association. The occasional typos work against a clear diagnosis.

I suspect that that question has been artificially generated. But I'm not sure.

This Q has a related Q, but an answer to both Qs is given only with a comment. This is unsatisfying because the core of the question obviously keeps recurring.

An answer in the generalizations list also links to this (finite, induction) question. Might be good enough for dup-closing, but by now amending the meta list seems to be more appropriate.

That (finite) geometric series question is covered by answers to this (infinite) geometric series question, listed in Meta's List of generalizations of common questions. I have added a comment, but not flagged as duplicate. It might actually be better to add the new Q (with currently 8 answers) to Meta's generalizations list.

NB: Daniel's aside reminds me of times some years ago where I used to lurk in the main math chatroom, silently enjoying the occasions where Daniel would offer a proof, live, yet perfectly ordered and free from clutter. Nowadays I do not visit chatrooms often, but here I have done it again, and what happens? Yeah :-)

Thanks, Martin and Daniel. Dup-closing seems suboptimal as well: The older has the better question; the newer Q is clearly deficient but has the most upvoted (and IMHO useful) answer. I'll just add another link to the comment section of the old Q for now.

(Thinking again... You have a point there. Merging the new answer in the old thread would not fit perfectly.)

@MartinSleziak Yes, but the other (older) infers that as the first step in the proof attempt given in that question. ($p$-groups have nontrivial center.) Anyway, the new Q has a link to the older one, and I just thought it would be nice to have the answer to the new Q accessible from the old Q. No strong preferences however.

Old Q with less useful answers, new Q with useful answer. I thought of flagging the old Q as duplicate of the new one, but perhaps it's best to merge the new answer into the old thread.

@quallenjäger: Look at the link near "LaTeX in chat" on this page

Looking for a nice geometry problem? There is one. It already has an answer, but finding a (mostly) coordinate-free reasoning would be great.

I suspect that that question has been artificially generated. But I'm not sure.

There is a thread where the comments had almost led the asker to believe that the problem had no solutions. Fortunately, there is a correct answer.

@CaptainGiraffe: Not at all. That's the point: The second factor could be any $(1 + x^r)$, as long as the integral converges.

@CaptainGiraffe: Partition the interval into $(0,1)$ and $(1,\infty)$. Substitute $x\to\frac{1}{x}$ in the latter to turn the second interval into $(0,1)$ again, then combine the two parts again. You will find that the $dx/(1+x^2)$ remains, and the other parts combine to 1.

Nice problem there. First I thought "Yet another small numbers coincidence" and looked for a counterexample. After searching for a while with Pari/GP without counterexamples, I looked closer and found a proof for a special case (where $H$ contains $p-1$), but not for the general statement. Sangchul Lee has found the general proof. Congratulations!

Projective geometry: Does anyone know a reference for the following: Given a reference triangle with Steiner point $S$ and a point $E$ at infinity, then $E$'s isogonal conjugate and $E$'s isotomic conjugate are collinear with $S$. This fell out from this thread, and a reference might be a useful addition.

Nice geometry question.

Interesting distance geometry question. Have to think about that.

Interesting geometry question, a generalization of Pascal's theorem to three conics.

This Q has a related Q, but an answer to both Qs is given only with a comment. This is unsatisfying because the core of the question obviously keeps recurring.

Here I don't get where the OP's problem actually is. Seems too easy, but perhaps I am assuming too much.

My best way of finding interesting questions so far: Look up the posts of a user with interesting answers. Somehow that can be full of recent posts to interesting questions in my tag set that I have never seen before. Puzzled.

@Semiclassical Thanks for the suggestion. Commented now, but without additional interpretation, so as not to change the spirit of Martin-Blas's answer.

@TobiasKildetoft Right suggestion... but then I feel it's too little an addition. Sigh.

@TobiasKildetoft: I'd like it more explicit -- I just expected it to turn up amog so many answers

6 answers, but nobody mentions the $3\times 3$ (volume) determinant with an all-ones row.

Fun with determinants

Sleepy now. Bye folks.

Note: resulting theta is in radians.

As an aside, it seems there is no way to delete useless queries again?

Aaaaaah, that explains it (I got negative time-to-vote up to -24h). Many thanks. (Grrr. So I cannot get a distribution of exposure time to votes. Damn.)

Hi there! It seems that there are (Mod) Votes.CreationDate earlier than the referenced Posts.CreationDate. Am I misinterpreting a relation there?

@MartinSleziak Thanks!

I am currently experimenting with SEDE. Seems like median time to close answered questions is around 7h, only 4% are below 20min. I'd like to narrow this down to questions with "missing context" close reason, but I cannot find the joins associating a post with its close reason.

Commenters suggest that I take my feature request on Meta.SE: Block early answers to Meta.Math first. I do not understand why. The arguments do not change, and implementation would be network-wide, or not at all, regardless of what Meta.Math thinks. Or have I overlooked some organisational detail?

Announcement: I have made a feature request on Meta.SE: Block early answers. It meets vivid feedback (against), but I think it is at least as good an approach as rate-limiting answerers or giving in to the dictate of speed and reducing the required number of close votes, or other things discussed on Meta.Math.

Recommended read

It's back. Thanks, just in case.

The thetaplot that I use as a userpic seems to have gone. Any idea why?