I'm doing a little research project on Harry Potter questions on SFF SE.
I would like a list of Harry Potter books, SFF.SE questions and chat comments involving time traveling robots.
I am looking to compile a list of several (10-50) of the most interesting/favorite Harry Potter tag questions that do not have a good canon answer.
In other words, where either:
there's no answer at all,
or the best available answer is "Probably this, but it's a guess and only JKR knows for sure",
or the best available answer is "this sounds 100% like a real plot hole, but here's a feeble and obviously inadequate attempt to retcon it using in-universe canon".
Please post ONE HP question link per answer, and if that question already has answers, try to explain why you feel the answer is canonically inadequate.
Also, if there's a Harry Potter question burning in your brain but you didn't ask yet (didn't get to it, or you are 100% sure it's a stupid "plot hole" question with no canon answer), please post it on the main site and link here as well.
circle army set cabal of Harry Potter self-appointed "experts" will pick some of the proposed questions for in-depth research, helped in choosing by how much each of the suggestions is voted on in the answers to this meta question (so, in the words of Al Capone, "Vote Early and Vote Often!")