# Help finding question

I am seeking a link to a question I posed myself, but which I can no longer find, either with Google site:https://mathoverflow.net or with StackExchange search (which I have not mastered). It was a question about the probability that unit-radius circles with centers randomly placed in a sphere in $\mathbb{R}^3$ are interlocked. My searches keep hitting this question, which is related but not what I'm seeking. Thanks!

• Could it be this? mathoverflow.net/questions/128940/… – Todd Trimble Apr 27 '18 at 17:13
• @ToddTrimble: YES! "Random rings linked into one component?" Perhaps the search was difficult because I used "rings" rather than "circles" in the title. Thank you! May I ask: How did you find it? – Joseph O'Rourke Apr 27 '18 at 17:27
• I think my Google search terms were "joseph o'rourke mathoverflow linked circles" and it was the third result appearing (and the first I tried). I figured "linked" rather than "interlocked" might give better returns. :-) – Todd Trimble Apr 27 '18 at 18:40
• @ToddTrimble: Shows how personalized is Google search now. That same string of words doesn't get me even close: four pages of misses. – Joseph O'Rourke Apr 27 '18 at 21:23
• I guess! But just now I tried "linked circles" in the search function for MathOverflow, and I found it round about result 5 (and result 2 under your name). Do you get the same behavior? – Todd Trimble Apr 27 '18 at 23:22
• @ToddTrimble: Yes, exactly the same. Very simple! Of course StackExchange doesn't personalize searches like Google does. – Joseph O'Rourke Apr 27 '18 at 23:53
• @ToddTrimble I would suggest that you could expand your comments to an answer. (Perhaps including, as in one of your comments, what exactly you used for searching.) If not for other reason, you deserve the credit both for taking the time - even if only in the form of a few upvotes on meta. And also the description how you searched might be useful for other users and it will be more visible in answer than comments. (And perhaps also the fact that Google returns different results for different people might be worth mentioning.) – Martin Sleziak Apr 28 '18 at 6:26
• I will add that if I search for joseph o'rourke mathoverflow linked circles as suggested in Todd Trimble's comment, I get the linked post among top results. (I have also added a link, so that if we compare whether the Google search behaves very differently for other users, we make sure that we are using exactly the same search.) – Martin Sleziak Apr 28 '18 at 6:28
• @MartinSleziak I feel my comments are ad hoc and don't rise to a methodology as your own answer does, and would be of limited use to others in a similar situation. Thanks for the invitation anyway. I got enough "credit" from Joseph's expression of appreciation, and I'm glad to have helped. – Todd Trimble Apr 28 '18 at 11:29

It is kind of easy to add suggestions how to search post fact, after Todd Trimble already found that the question is this one: Random rings linked into one component?.

• There is a operator user:userid which restrict the search to posts of a specific user. For your own posts you can user user:me. Or if you go to your profile page you have the search with your userid is automatically shown in the search box. (And checking the profile is also a way how to find out what is userid for another user, if you need it. For example if you want to search for posts by specific user.)
• If you want to search only among question, you can use is:q.
Of course, if you recall more information about the question, you can improve your search. For example, if you remember who answered the question, you can try among the answers of this user. (To search among answers you can use "is:a". For example, if somebody looks for the same questions and they remember that it was answered by Benoît Kloeckner, they might try to search among answers by this user in some related tag.) In fact, if you remember one of the answerers, you can combine this with the fact that you are searching among your questions - this cannot be done using the internal search engine, but you can still use data explorer (SEDE) for this. For more details see this post: Is it possible to search for posts/questions of an user $X$ commented on/answered by the user $Y$?
• This is very useful, Martin! Even just user:me is quite helpful. – Joseph O'Rourke Apr 28 '18 at 11:38
• Well user:me indeed restrict the search results a lot. Although it is different for users like me (I only have to search only among a few posts if I am looking for my own post) and some exceptional users who even after this restriction get more than thousand posts. :-) – Martin Sleziak Apr 28 '18 at 12:03