# I voted mistakenly to close as duplicate. When I realised my mistake, my comment explaining why was deleted.

I refer to this question: Comparing logarithms with different bases.

Over-hastily, I flagged it as a possible duplicate of How to compare logarithms $$\log_4 5$$ and $$\log_5 6$$?.

I also thought it was a duplicate of Comparing $$\log_5 6$$ and $$\log_6 7$$ - itself closed as a duplicate.

Later, I realised my mistake, and posted this comment (fortunately, I retained it in my own notes):

On second thoughts, this is not a duplicate of the other question, because none of the answers given in that case, including my own, can be applied in this case! (Ditto this.) It is interesting to ask if there is some general result that can be applied in this case; or at least, some other argument than the one given by the questioner himself (which I take it is essentially that $$4^4 > 3^5$$ and $$10^4 < 7^5$$, so $$\log_34 > 5/4 > \log_710$$). I suppose I should withdraw my close vote, if that's possible. Meanwhile, I've upvoted the question.

Right or wrong, it was a rational argument. It even had some mathematical content, relevant to the question, so I don't think it can fairly be described as merely a "meta" comment.

Why was it deleted? May I restore it, or restore some cut-down version of it? If the latter, then how should it be edited?

• Are you sure you successfully posted that comment to begin with? It's possible that the system rejected it for being too long, and you didn't notice. – Misha Lavrov Oct 24 '18 at 14:08
• I've posted Comments in cases where I disagreed with proposed duplicate Questions, and probably a few cases where I came to see my own initial judgement was wrong. So there's nothing wrong with making such a Comment. Perhaps it was deleted as part of an exchange flagged as no longer relevant (or overheated?), although sensible enough itself. There is a dedicated thread here on Meta to propose reopening of closed Questions; no way to retract a close vote that I know of. – hardmath Oct 24 '18 at 14:17
• @MishaLavrov I'm almost sure that it was successfully posted; but I also think it was quite likely to have been exactly 600 characters long (I quite often push the limit of comment space in that way); and although that has never caused a problem before, perhaps it did on this occasion? Perhaps I slipped up in one final edit, and as you suggest, didn't notice? But then, wouldn't an earlier version have survived? – Calum Gilhooley Oct 24 '18 at 14:17
• @hardmath I'm practically certain that there was never any irrelevant or overheated exchange (and I'm entirely certain that my comment was not posted as part of such an exchange!), so the mystery remains. I'll move to reopen the question, when there has been enough time for discussion here. (That's assuming that I haven't been persuaded to desist!) Thank you for the pointer - I was only vaguely aware that there was some way to reopen a closed question. – Calum Gilhooley Oct 24 '18 at 14:34
• Some idea of what may have happened can be gathered from the Question's timeline, which shows you posting Comments before and after the point where the Question was closed. I have no idea whether deleting a Comment removes that entry from the timeline. – hardmath Oct 24 '18 at 15:16
• @hardmath For what it's worth, I posted the comment about 12 hours ago, certainly after 4 a.m. BST (= GMT+1), and certainly before my two comments still visible in the timeline, posted 12 and 11 hours ago. It seems extremely unlikely (verging on impossible) that, had it disappeared as a result of some technical glitch at roughly the time of its composition, I would not have noticed this when posting the other two comments, one of them about an hour later. (Thanks again, by the way - I didn't even have a vague idea that such "timelines" existed!) – Calum Gilhooley Oct 24 '18 at 15:25
• I thank the magician, whoever it was, who brought the comment back from the dead. – Calum Gilhooley Oct 26 '18 at 11:26

Your Comment contained a link to an older Question. Although this Question was not the final target chosen by voting to close-as-duplicate, someone may have voted to consider that target the duplicate, or the system may have identified that link as a duplicate of the target that was eventually chosen.

What is known is that when a vote to close-as-duplicate becomes finalized, the system removes a Comment which identified that proposed duplicate for the Question. Often this means the system removes a system generated Comment with wording "Possible duplicate {link}...". In other cases it can be a manually introduced Comment linking to the proposed duplicate, with or without a vote to close-as-duplicate by the poster.

While this mechanism is helpful in cleaning up a Comment that has become moot (because the "possible" duplicate has been voted on), it could have minor unintended consequences.

Comments are considered "ephemeral content" on StackExchange, but posting the Comment as you did is not wrong. It simply may have been removed by the system routines when the close vote was finalized.

• Light dawns! Although I can't remember for sure (insomnia caused this, and I'm now fading fast!), I have a dim memory that although my close vote was not the first to be cast, it may (so I speculated at the time) have been the first one cast by flagging the question as a duplicate, because I'm almost (not entirely) sure that a "Possible duplicate..." message was automatically generated in the usual way, with my name attached to it, rather than name of anyone who had voted earlier. I did wonder vaguely if my long comment could have gone in tandem with that one. You have made that thought clear. – Calum Gilhooley Oct 24 '18 at 16:25
• The system should only be deleting the auto-generated comments. – The Great Duck Nov 4 '18 at 0:57
• @TheGreatDuck: It is tempting to think that there is a clear cut distinction between the system generated Comments and ones that are manually written. However there are some subtle gray areas. A system generated Comment is assigned to the User who votes first to identify a target duplicate. That User can then edit the Comment as they see fit, and I've done so on occasion to point out strengths or weaknesses in my identification of the dup. On the other hand a User may manually post a Comment with essentially the same content, saying that a previous Question is a "possible duplicate". – hardmath Nov 4 '18 at 1:26
• @hardmath oh so the system itself doesn't tag the post id or whatever? – The Great Duck Nov 4 '18 at 1:27
• @TheGreatDuck: Not as far as I know. The Comment is "owned" by a particular User, and subsequent close votes to that target duplicate result in upvotes on the Comment. – hardmath Nov 4 '18 at 1:30
• @hardmath "subsequent close votes to that target duplicate result in upvotes on the Comment." well that right there proves that the comment has a reference within the software. Unless similar phrased comments also get upvoted. – The Great Duck Nov 4 '18 at 1:35
• @TheGreatDuck: Various Meta SE threads such as this may provide more insight about the system Comment removal mechanism. – hardmath Nov 4 '18 at 2:04