# Puzzles which requires quite special knowledge

I was reminded of this puzzle: What is the "linguistically hardest" number less than $10^9$? , that is much more nice in Russian language and started to wonder - why not?

Hereby the question - what should be a policy for this puzzleSE about question, which require knowledge of things, which not everybody knew. Like foreign (but quite popular) languages, history, chemistry, etc.
If chemistry puzzle may be appropriate on chemistrySE, puzzles like What is the "linguistically hardest" number less than $10^9$? would not be appropriate on any languageXSE, since they only use language to build up the puzzle, not ask about it linguistical and usefull properties. So there won't be any other place on SE for such puzzles.

• A puzzle is a puzzle, do you not agree that they're still puzzles? Just because some cannot answer don't mean others can't. It's still a puzzle for some people! Jan 3 '15 at 14:23
• @warspyking, this is kinda my point. But there still must be limitations. Plus i saw some puzzle-qustion, which involved knowledge of the material (easy to find in any reference book) was closed.. I think such a puzzle will be down-voted very quickly, people get irritated facing something they doesn't understand. Jan 3 '15 at 14:43
• Down votes should not be used to express that you do not like the puzzle, or that you cannot solve it. It is supposed to be an indicator as to how how much quality the question has. Jan 3 '15 at 16:00
• @warspyking, should and is are different things. As a matter of fact if you (a person) can't solve a puzzle you start to think that the problem probably in a bad formulation of the task. I'm talking about this fact. I saw this many times. Do you? Jan 4 '15 at 9:40

In general, questions that require specialized knowledge are fine. Does everyone on Physics.SE know QCD? No. Can you ask about it? Of course. Does everyone on SO know Ada? No. Can you ask about it? Of course. I think this goes for puzzling as well. Requiring specialized knowledge is fine, see for instance Hidden in plain sight - By what method do these images hide a prime number?. How many puzzlers know what a 2d-fourier transform is?

(Natural) language is a little different. The entire network requires questions and answers to be in English, except on language-specific sites, where it may be in the other language. I'd say if a riddle relies on something like knowing a particular word or phrase in another language that's OK, but if it needs any real command of the language (say, ILR 1-2+) it's too much.

• Just a comment: Note, that all your examples where "to require a special knowledge is fine" are done basing on special knowledge in the field of the given SE: QCD is a field of Physics, and Ada is a field of programming. Jan 3 '15 at 20:45
• Also i would specify: "The entire network requires questions and answers to be in English, except on language-specific sites". Note, that on English.SE, for example, questions and answer still must be in english, it's just they can involve words in other language as a Subject, which is asked\answered about. Similarly with SO, which uses computer languages (i don't see substantial differences here between Russian and C++, both have grammar and vocabulary). There are number of questions in PuzzleSE, which uses encoded phrases, that is also a nonenglish language. Jan 3 '15 at 20:50

I basically agree with Kevin's answer above. You have to ask yourself: What happens if a posted puzzle requires special knowledge?

a) Somebody has this knowledge and solves the puzzle - everybody learns, and the puzzle (if it is good) will be very much liked (perfect puzzle!)

b) Nobody has this knowledge. Nobody answers this question.

b1) It stays open forever and both author and other readers are okay with it... (no harm)

b2) The author wants somebody to solve this puzzle - time to add some hints! (no harm)

b3) The author doesn't care if it solved, but readers are. They think the puzzle unsolvable. Potentially, they will start down-voting. (so what?) The author can still add hints, or don't mind it being down-voted. (but no harm is done.)

Now consider what happens if some author posts lots of special-knowledge puzzles: If they fall in group a): perfect. If they fall in group b): Either more and more people pick up special-knowledge, leading to case a), or more and more people down-vote the questions, until the author stops posting them. So either the solvers or the puzzle-author learn. Again a positive outcome!.