Imagine you are minding your own business when you receive an email from someone who claims to have discovered the Answer to the Ultimate Question of Life, the Universe, and Everything. He provides some "details" about his theory, then says he wants to meet you and / or arrange a time for a phone conservation to discuss it. What should you do?

The only thing I've seen is this 1983 article by Underwood Dudley about what to do when the trisector comes. Dudley says not to examine the trisector's proof, and also not to direct the trisector to the proof that trisection is impossible. Instead one should send computer-generated results showing that the trisection is imperfect. Problem with this is that it only works for questions that can be attacked by computers - there was a recent question here on Academia SE challenging conservation of angular momentum which this won't work for.

What are some general guidelines for dealing with these situations?

Edit: ignoring an email is easy, but what if the crank calls or visits in person?

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    insti.physics.sunysb.edu/~siegel/quack.html Commented Jun 19, 2018 at 1:42
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    Related 1 Related 2. Additionally, an approach I remember seeing somewhere, but couldn't find: When sent a proof by a crank, the professor would send them a previously received crackpot proof, and state that they would go over the new crank's work if and only if the crank could find at least one of the errors in the other one.
    – Ray
    Commented Jun 19, 2018 at 20:47
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    I really like this article, which could be seen as a modern follow up to Dudly (and also one that is focused more on physics than on math): aeon.co/ideas/…
    – Vincent
    Commented Jun 20, 2018 at 12:00
  • Comments are not for extended discussion; this conversation has been moved to chat. Please do not use comments to answer the question.
    – Wrzlprmft
    Commented Jun 20, 2018 at 12:07
  • The answer is 42....
    – Solar Mike
    Commented Mar 10, 2020 at 10:03

9 Answers 9


This happens far less frequently than inappropriate requests for postdocs that have absolutely nothing to do with your area, invitations to participate in conferences that have nothing to do with you, invitations to serve as section editor on predatory journals, .....

Handle them all the same. Use your delete button.

A call or visit is harder to deal with. A polite "... very interesting, but I don't have the time to follow up on this" might get you off the hook. If the person shows up at your door more than once, I recommend calling security.

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    I agree with most of this; however, calling security on a person merely for visiting multiple times seems like an unreasonable escalation to me, especially if you have never previously escalated beyond the polite on previous visits.
    – Ben
    Commented Oct 20, 2021 at 20:31
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    @Ben First visit: I don't have time. Second visit: I don't have time, you are interfering with my work. Third visit: "Hello security? Please come to my office."
    – Bob Brown
    Commented Jun 7, 2022 at 20:40
  • I wouldn't call security to ask them to remove the person. I'd call them after the second visit to say "I may be in a situation". I have no way of knowing if the crank is a known problem to them or not. That's their job. Commented Jun 8, 2022 at 20:03

Ignore the crank.

Unless you are in some location where you are required by law to respond to communications (I remember reading here about one country where it was indeed the case that it was required to answer emails as part of "open records" laws), you are under no obligation to waste your time on a crank's musings.

If it amuses you to respond, feel free to do so, but you waste your time at your own peril!

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    I work for a German government research institute. We are required by law to respond to communication from citizens that was directed to the government. We once had to answer a crank who claimed photosynthesis doesn't use CO2 as a substrate. My colleague had fun for about two years with that one. You are much better off if you can ignore them.
    – user9482
    Commented Jun 19, 2018 at 6:28
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    @Roland, perhaps you could clarify whether the legal obligation is satisfied by a reply which states simply "Your correspondence has been received and noted." Commented Jun 19, 2018 at 8:12
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    There are expectations to make citizens feel heard and taken seriously.
    – user781
    Commented Jun 19, 2018 at 23:10
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    The last line seems incomplete without some reference to James Veitch, so I hereby add that. For more entertaining details, search YouTube or TED.com.
    – WBT
    Commented Jun 20, 2018 at 0:36
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    I honestly would like every governmental university (or research institute) to answer such questions in some way. Many of these questions are genuine. It is sad that most academics talk so bad about "cranks" which are just so unfornate to not have collage educatoon and do thus not understand the rules of academia.
    – Udank
    Commented Jul 6, 2018 at 16:30

Follow the peer-review model with some tweaks:

If the work is clearly flawed and so off the mark that nothing can come out of it, ignore. [Desk reject]

If the work may have some iota of sense, but it isn't worth your time to get into it, write back suggesting a different forum, like a blog post. [Reject and suggest transfer]

If you are marginally interested, but not sure whether it's worth it, ask them to try presenting it better/differently with more proof. [Reject and resubmit]

If you think it deserves a chance, but can't get into it yourself, lightly share with your colleagues/students over the coffee table and if anyone seems interested, let them take it up. Alternatively, as suggested by @jpmc26, you could ask them directly if they would be interested to detect preliminary errors that could be pointed out. Purely voluntary, of course.[Assign reviewers]

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    Would asking your students to review it for errors or if they're interested in doing so be a reasonable variation on the last one? This might act as a sort of initial smell test.
    – jpmc26
    Commented Jun 19, 2018 at 6:20

I read somewhere that a professor dealt with this issue by introducing such cranks to other cranks. "You might want to talk to Bob about your theory, I'll introduce you."


I agree with @aeismail that you should try to avoid the crank. That may not be possible though. Underwood Dudley wrote a book "Mathematical Cranks" (an MAA press book) about the subject. He has a chapter (Case Study of a Crank, I think; if not, The Making of a Crank) devoted entirely to a crank he refers to as G. K.. This person happened to be an alum of the school at which I taught. When I assumed the Chair of the Mathematics Department, I began to receive "stuff" from G.K., which I stuck in my files and ignored. My luck ran out one day when he happened to reach me by phone in my office (we did not have caller ID at the time). He asked me what I thought about the things he had been sending and I told him that I thought his ideas were without mathematical merit. He proceeded to call me all sorts of vile things and eventually hung up. I have no idea what he said about me in subsequent writings, and don't really care.

Interestingly enough, he had called my residence some time before this and my teenage daughter fielded the call. She reamed him out about it and invited him never to call my home again, which he never did.

Along the way (cranks can be very persistent) he asked me for a recommendation for the national medal of science or something. I ended up calling the organization for advice on what to do. They asked me who the person was and I told them. The person on the phone laughed and told me to throw the form away.

Among G.K.'s mathematical achievements were the "discovery" of "subzero pi," and the recognition that since $e=mc^2$ we must have $e=m(a^2+b^2)$ via the Pythagorean theorem.

I corresponded with Dudley and George Andrews about my encounters with G.K., which they found quite amusing. Although I found G.K. to be harmless, a colleague of mine in the department, who had been a classmate of G.K., was afraid he would come to school and use his military commando background to harm members of the department who didn't praise his dubious achievements. That didn't happen, but I cannot say I dismissed his concerns completely.

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    +1 since $e=mc^2$ we must have $e=m(a^2+b^2)$ via the Pythagorean theorem --- This is totally priceless! I must confess to spending more time than I should have 15-20 years ago reading stuff by this guy, especially the diaries he posted on usenet when he made road trips. Commented Jun 19, 2018 at 18:50
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    @Dave L Renfro - This is the first I have heard of Archimedes Plutonium. I'm going to look into him further. My guy was also a megalomaniac. He had translated the bible into verse, and received some award from the Beaux Arts Society in New York. I recall a piece about him, I think on CNN, after his bible translation. He always insisted that his name be followed by the letters FRM, for being the world's foremost renaissance man. I would mention his name, but I don't want to speak ill of the dead (he died just a few years ago). Commented Jun 19, 2018 at 19:23
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    I made perhaps a couple of dozen posts around 1999-2002 or so under the name Megalomanious Kryptonium to satirize AP, in which I adopted certain writing mannerisms of AP that regular readers of AP's stuff would immediately recognize, such as one from October 1999 that I reposted at the bottom of this post. Most, if not all, of my Megalomanious Kryptonium posts can be found using this search. Commented Jun 19, 2018 at 20:08
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    @AlecosPapadopoulos, $a$ and $b$ are left as an exercise for the reader.
    – shoover
    Commented Jun 20, 2018 at 21:51
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    @shoover - Considering he filled out his application for the national science medal and expected me to just sign and submit, I'm sure he had an obit composed and ready to go. Commented Jun 21, 2018 at 4:07

I knew a very eminent astrophysicist who would receive hundreds of these emails claiming to disprove Einstein and relativity, discovering life on Mars, alien visitations, space mirrors, critiques of the big bang, flat earth, etc.

He would respond in a vaguely positive way, "This is very interesting work, but I don't know the answers to these important points you raise. Let me point you to someone who can help:" and give them the email address of another random crank that had previously contacted him.


Don't treat someone as "a crank" to begin with

I'm going to put forward a slightly alternative take on this than the other answers. While I agree with some of the practical suggestions for a polite dismissal of interest in work that is not fruitful, I think it is a bad idea to begin with the dehumanising premise that a person is "a crank". People described in this way can more accurately be described as amateur analysts with substantial gaps in their knowledge, which lead them to attempt to solve problems that they are ill-trained for, or use methods they misunderstand. Sometimes (though not always) this is combined with a skepticism of existing authorities in the field.

I agree with the general view that one should ignore non-meritorious contact, and in most cases a deleted email is the solution. However, if academics do choose to engage in discussion with amateur analysts of this kind, I think it is incumbent on the academic to show the same kind of basic humanity, decency, patience and politeness that would be used with an undergraduate, grad-student, etc. If the work at issue is extremely poor, it will not generally be frutiful to wade into its details, though one might outline some basic errors or false premises if that is simple to do. Irrespective of this, a reasonable thing to do here (if you choose to communicate at all) is to direct the amateur analyst to resources that they can follow to allow them to discover the problems with their method on their own. If the analyst is operating at a level where those resources are too hard (e.g., they lack sufficient training in a particular field), you might instead recommend courses or books that will give them more training in a particular subject.

One of the things that can be observed about extreme cases of so-called "cranks" is that if they are cut off completely from academic feedback, particularly in the early years, this may lead them to proceed hermetically, and some can work for many years ---or even decades--- developing a long and detailed theory without merit. I suspect that early cases of hostile or condescending rejections from the academic world (combined with the snarky dehumanising attitude exhibited on forums like this) sometimes leads such people to believe that academia is corrupt and insular, which makes them more inclined to proceed without any effective check on their work.** I'm not sure if anything can prevent this, but it seems like it might be worthwhile if such people were directed early on to useful learning resources, in a way that grants them some dignity, and some sympathy for the fact that they are trying their best to solve problems with the skills they have at their disposal (not unlike our students).

The final helpful thing in dealing with such cases is to highlight the benefits of blinded peer review as a useful tool for amateur researchers. We all know that peer review has its problems, but whatever its faults, it is an extremely useful source of assistance in academic writing, particularly for researchers who are inexperienced in publication of work in academic journals. Use of blinding protocols should put amateur researchers somewhat at ease if they are concerned that academia is an exclusive club that discriminates against outsiders. Helping such researcher simplify and clarify their work, and present it to the rigours of blinded peer review, is something that could potentially be very valuable for any researcher with the patience to assist. As professional academics, we are extremely patient with our own students (many of whom are appallingly ignorant) so let's extend that patience and courtesy more broadly.

** And let's be honest; academia sometimes is corrupt and insular.

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    Yes, indeed. Very good points. :) Commented Oct 20, 2021 at 22:05
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    Thank you for calling for a bit of empathy. Commented Jun 8, 2022 at 9:15
  • This is best answer. Before ignoring a "crank", I will first politely suggest some readings. I will start to ignore that "crank" only if he clearly misunderstand all readings I suggested.
    – High GPA
    Commented Jul 4, 2022 at 23:23

A general guideline for these situations is to communicate your message (whatever you decide) to this person in a polite and gentle way.

The most successful people in my university are those who are excellent in their field and extremely nice, respecfull and humble because they understand the best how much they don’t know.


Introducing a crank to another crank is always a grand idea. They never have any trouble accurately diagnosing the other one.

In any given field, there are lots of enthusiasts out there in the gen pop that lack the competence (formal training, background, or just the intellect) to play a role at the top professional level. In sports, we have "grass roots" activities - amateurs who are not anywhere near major leagues but still spend their time meaningfully. In art, lots of people paint and sculpt without necessarily believing they are the next Michelangelo. In astronomy, we have the star gazers who can make a real contribution. Birdwatchers - ditto.

But in maths and physics, we somehow do not manage to have a healthy relationship with a broader population of enthusiasts, and in the final analysis we must admit that this is unfortunate.

Very rarely I come across an enthusiast who is at least vaguely aware that he (almost always a he) is but a dabbler and willing to admit that he has probably made a mistake or two. Such an enthusiast is not a true crank, by Dudley's criterion that a crank is someone who will not consult (this also applies to academics, at times!). But most will not be told, and simply cannot be told, because of the Dunning-Kruger effect (often aggravated by some sort of paranoid-megalomaniac resentment that eerily surfaces before too long in almost all conversations).

Before the internet, cranks would utilise purple ink and mimeograph and mass mail and complain about being ignored. These days, they can put their stuff out there and stand a good chance that a professional (often a young one) will bite and patiently explain that, e.g. limits just don't work the way the crank believes they do.

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