By 'old', I mean questions older than 6 months.

If so, does anyone know the correlation between age of the question and Resurging?


2 Answers 2


Apparently it can.

This question, asked in 2011, was the most famous unanswered question on the Sci-Fi & Fantasy SE until one Kyle Hale finally found the solution (netting nearly 6000 rep from a single post, which has earned more points in bounties than any other answer on the entire Stack Exchange network).

The answer was posted late in 2015, more than four years after the question was asked. The massive upsurge in votes on both question and answer, due to the community's collective astonishment at the supposedly unanswerable question having been solved, was enough to send it into the Hot Network Questions despite its age, according to this comment:

I thought of the story as soon as I saw the post in hot network questions. Now I am lamenting not having seen it in the unanswered section. I still think about that story whenever I see two fives on a clock. – Engineer Toast Oct 23 '15 at 19:47

  • 1
    Fascinating. So there's either something else to the formula, or SE manually intervened in this particular case. Mar 24, 2016 at 12:05
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    @Nathaniel if it really was in HNQ (I would prefer a screen shot to make believe), this would definitely be due to some manual intervention from SE. Four years is about 30,000 hours, put this number into formula and account that question has only one answer and you'll see that score is guaranteed to be too low to enter the list
    – gnat
    Mar 24, 2016 at 12:32
  • @gnat Sadly I don't have a screenshot this long afterwards, and probably nobody else does either. Does SE keep an archive to record which questions have ever been in HNQs? Mar 24, 2016 at 12:37
  • no they don't and they won't -- "It would amount to little more than a tool to feed speculation and paranoia..."
    – gnat
    Mar 24, 2016 at 12:49
  • One other thought—are you sure that you saw it on the desktop site's HNQ list? Or were you on a mobile app and it said this post was "hot"? They aren't the same thing in my experience. Mar 24, 2016 at 17:08
  • @Nathaniel I dunno, ask Engineer Toast. I don't remember seeing it on HNQ myself. Mar 24, 2016 at 18:59
  • Ah, okay, I misunderstood; I thought you had seen it as well. Thanks. Mar 24, 2016 at 18:59
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    Rand, here's a method we can use to verify whether this hit the HNQ. @gnat
    – Fiksdal
    Jun 24, 2016 at 6:15
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    Wayback Machine doesn't lend any evidence – none of its captures show this question on the HNQ list. Page 1: Oct. 22, Oct 23, Oct 23, Oct 24, Oct 24 Jul 25, 2016 at 20:43
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    Page 2: Oct 23, Oct 24. Jul 25, 2016 at 20:43
  • Hey, Rand, could you take a look at this question? @Nathaniel
    – Fiksdal
    Aug 26, 2016 at 9:44

Per How do the “arbitrary hotness points” work on the new Stack Exchange home page?, this is the formula for HNQ:

[(MIN(AnswerCount, 10) * QScore) / 5 + AnswerScore] * Site Factor
         MAX(QAgeInHours + 1, 6) ^ 1.4

A post that is 6 months old would have a denominator of ((182.5 * 24) + 1) ^ 1.4 = 125,373.

Typically, the number of "arbitrary hotness points" needed to make the HNQ list is in the vicinity of 7–10. Right now the lowest post has 8.574:

enter image description here

Thus, in order for a 6-month-old question to get on the HNQ list, it would need to have a numerator of around 1,000,000.

The most important parts of the numerator are the AnswerScore (total score of all answers) and the Site Factor. On most sites, based on my own calculations, the site factor is around 40 (it's lower than that on Stack Overflow).

That means that if that question had a hundred answers, and they averaged a hundred upvotes each, the numerator would be around 400,000, still well below what would be necessary to get on the list.

TL;DR: It's basically impossible for a question that is several months old to get on the HNQ list.

  • 1
    There are questions on Stack Overflow that have 21k answer score, but they are very old and the factor is lower on SO.
    – wythagoras
    Mar 24, 2016 at 7:10
  • @wythagoras for Stack Overflow questions system makes special adjustment that plainly divides their "hotness score" by 5
    – gnat
    Mar 24, 2016 at 9:36
  • See my answer below/above. Are you sure you haven't gone wrong in your calculation somewhere? Mar 24, 2016 at 11:59
  • @randal'thor Yeah, I'm sure, but that's certainly a puzzling example. It would take well over a million upvotes for that formula to evaluate high enough on a question that's four years old. Mar 24, 2016 at 12:10