I used to love the math.stackexchange web site. It was a great place for an amateur to get feedback and to learn about historical math papers and recent work. It was a great place to test out one's intuition about deeper questions in a forum that was rigorous and provided supportive insight from other amateurs and from math experts.

For the naive amateur, this was the preferred site over a more advanced web site such as mathoverflow.net

In the last few years, this tolerance for amateur speculation has disappeared as far as I can tell. Questions about papers in arxiv.org which represent learning opportunities are now discouraged and flagged as improper and closed. Here's an example: Status of the Nichols claim to proof of the Collatz conjecture?

I don't have a problem with this change in the approach. This web site is community-run and if the values of the community prefer to emphasize textbook and college mathematics, that's what this web site should focus on. If my interest does not represent the focus of this web site, it is time for me to move my attention and focus to another site.

Now, that amateur, speculative questions are discouraged, is there another stackexchange site that would be appropriate for these types of questions?

Specifically, a web site that would welcome questions that relate to:

  • flawed proofs where a person is looking to understand the mistake
  • papers on arxiv.org that are clearly flawed but where the details of the flaw would be of interest to non-experts
  • general questions that cover standard approaches to open mathematical problems (typically topics that are covered in wikipedia and relate to mathematical papers on these topics)

If no such stackexchange site exists, would it make sense to start one? This would have the added advantage of reinforcing the preferred content on this site and helping to move discouraged content elsewhere.

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    $\begingroup$ Your first category seem to fall into the tag fake-proofs. I doubt if it is really off topic here on MSE. $\endgroup$ Commented Feb 2, 2022 at 22:26
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    $\begingroup$ Good to know. That tag seems to cover 2 of the 3 bullet points. $\endgroup$ Commented Feb 2, 2022 at 22:47
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    $\begingroup$ But note that just because there's a tag for something on the site doesn't mean that any and all questions described by that tag are well-received on the site. $\endgroup$ Commented Feb 3, 2022 at 1:49
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    $\begingroup$ I think that it is reasonable to require that a poster does their homework before posting. That is, they search to see if the question has already been asked, they read the relevant wikipedia article or standard web content before posting, make their question very clear, and most important, is very open to any feedback received. My assumption is that this tag would only be well-received if the poster follows these requirements. $\endgroup$ Commented Feb 3, 2022 at 4:52
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    $\begingroup$ @ArcticChar not being off-topic is not the same as "being welcomed" (see Gerry Myerson's comment). The problem with "fake proof" posts in that most often, they are related to 2-3 fundamental errors in reasoning, addressed hundreds of times on this site. So at best, you can say, a couple such questions might be on topic, if they are not duplicates, fundamentally, of other, previously answered questions. $\endgroup$
    – amWhy
    Commented Feb 4, 2022 at 17:37
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    $\begingroup$ Have you checked out the chat rooms? I don't know if there is a specific room for what you mention, but I do know that the standards are looser there. And if there isn't one, maybe you could start one? $\endgroup$
    – JonathanZ
    Commented Feb 5, 2022 at 3:55
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    $\begingroup$ Thanks for the suggestion. I have not tried chat rooms. I was very happy with how my questions were received until they started getting closed and deleted by the community. I was asking this question primarily to see if the time was right to find another web site to ask my questions. I will try out the tag and chat rooms in the future. $\endgroup$ Commented Feb 6, 2022 at 20:05
  • $\begingroup$ @LarryFreeman FYI, among the list of chat rooms, one you should consider is Mathematics. Note I don't usually use it myself, but from its room description, my few previous visits and how I've seen it being referenced on other chat sites, I believe you should be able to ask relatively short & concise questions (that also can be answered fairly easily) about any math related topic, including those that are generally considered to be speculative. $\endgroup$ Commented Feb 9, 2022 at 3:43
  • $\begingroup$ @LarryFreeman As for your questions being closed & deleted by the "community", I assume you mean members of this site. However, I believe most questions with no undeleted answers are deleted instead by the automated Roomba script (although the post will usually show as it being deleted by the Community bot). This answer states that "... (as of $2022$-$01$-$12$) the recently deleted questions/answers pages to show all deleted questions and answers". ... $\endgroup$ Commented Feb 9, 2022 at 3:44
  • $\begingroup$ @LarryFreeman (cont.) Thus, to investigate this as far back as you wish, on your Profile Summary page, click "View all $367$ questions" and then the "Deleted Questions" link at the bottom. You should be able to see who or what deleted each of those questions but, if not, then check the Timeline (i.e., click the clock icon on the left). Should this still not be available, please let me know (even just the question ID's are sufficient) so I can check on them for you. If you do this check, I believe you'll find that very few, if any, of your questions were deleted by actual community members. $\endgroup$ Commented Feb 9, 2022 at 3:44
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    $\begingroup$ Thanks John. I appreciate the information and your feedback. I was surprised when the last question was closed and deleted. I was thankful that it got answered before the delete. $\endgroup$ Commented Feb 9, 2022 at 7:54

1 Answer 1


Questions about papers in arxiv.org which represent learning opportunities are now discouraged and flagged as improper and closed.

As one of the close voters of the question you linked to as an example, note the issue for me was instead that the OP was basically asking us to try to refute or verify an online paper written by an apparently different person. To me, that question didn't have much context (e.g., the OP did not make much, if any effort, to check the paper themselves and was not specific about anything which may be wrong with it), with it being somewhat similar to a PSQ (Problem Statement Question). To the best of my knowledge, these types of questions have never usually been acceptable on this site. Also, I've read several MathOverflow meta posts and various comments which indicate they are also generally not acceptable on that site either. An example, from just about a day ago, is LSpice's question comment of:

It looks like you may be asking for help checking or completing a proof. In general, MO is for asking specific, focussed questions with a well defined answer, not for checking or completing a research project.

If your referenced post of Status of the Nichols claim to proof of the Collatz conjecture? had, instead, been a more "specific, focused" question, such as with it including something like

In section $1.2$, I don't understand how equation $3$, i.e., $$\text{<Equation }3\text{ expression>}$$ is valid. Due to condition $A$, then doesn't the $B$ theorem apply here so that equation doesn't even converge?

then, instead of voting to close, I would have likely instead done at least one of: just bypass the question, upvote the question, check on the issue in the linked paper, write an answer explaining how the concern is valid or doesn't apply and/or vote to reopen the question if it were closed.

Several months ago, there was a video on a popular series (I believe it was this Veritasium one suggested in soupless's comment) about the Collatz conjecture. This site then got quite a few posts likely stemming from this, e.g., of people who claimed they have solved the conjecture and asking us to verify their proofs. I got the impression from various question comments, the CURED chat room, etc., that this annoyed some members, with anything to do with Collatz then becoming somewhat taboo. Also, there were some related comments in the chat room expressing concerns about the use of the and tags.

Sometime later, I believe it was around late November, you posted a question asking about your attempt to prove a quite restricted version of the Collatz conjecture you had come up with. Your question explained the background techniques you were using, what the variables were and stated your proof attempt relatively well (e.g., quite directly and succinctly). You also indicated where you thought there might be an error, with a question comment indicating a mistake (I believe it was in the part you suggested), and with you confirming it was an error.

As far as I could tell, your question met the various conditions mentioned in the How to ask a good question. post, with many other rather similar questions being asked here, but with few of them being closed and many being answered. I was somewhat surprised your question was closed, with it now being deleted. The Collatz conjecture association may have been a factor, but you could also perhaps have improved your question by, for example, explaining in more detail about why you weren't confident about the one step you mentioned.

From my perspective, there has not been any overall change, at least relatively officially, in the acceptability of questions about speculative mathematics over the past few years, as long as they are otherwise good questions, such as having appropriate context (if I'm mistaken, I hope somebody, in particular a diamond moderator, will explain any such change, e.g., by writing an answer here). Nonetheless, regarding sites where such questions might potentially be more welcomed, I don't know of any offhand.

IMHO, you're the type of conscientious member we encourage to join and contribute. Note I have found your questions to be generally quite well written, with some of them being among the most interesting (and sometimes challenging) ones I've read here. Regardless of whatever extent you continue posting here or somewhere else instead, I hope you get high quality, constructive feedback so you can continue to learn and grow your mathematical skill & knowledge.

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    $\begingroup$ Tangential, but maybe the Collatz video is this from Veritasium? $\endgroup$
    – soupless
    Commented Feb 4, 2022 at 7:27
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    $\begingroup$ @soupless I thought the video occurred somewhat later, but I find time seems to often pass for me faster than I expect. Nonetheless, I seem to recall now it was stated the video was from Veritasium, with Numberphile being mentioned elsewhere instead. As such, I've updated my answer to replace my suggestion of Numberphile to instead mention your video. Thank you for the suggestion. $\endgroup$ Commented Feb 4, 2022 at 19:58

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