3 ms·
A better title: The fifth hyperfactorial: 5⁵ × 4⁴ × 3³ × 2² × 1¹ milliseconds is exactly 24 hours. A sidereal day is not exactly 24 hours, it is closer to 23 h
by atonalfreerider 9y ago
A better title: The fifth hyperfactorial: 5⁵ × 4⁴ × 3³ × 2² × 1¹ milliseconds is exactly 24 hours.
A sidereal day is not exactly 24 hours, it is closer to 23 hours 56 minutes and 4.1 seconds.
- hanbura 9y agoThe word day is ambiguous, but calling it 24 hours is not perfect either. A 24 hour period can include leap seconds, meaning it can be one second longer or shorter than 24 * 60 * 60 seconds. (At least that's how ISO8601 defines time periods: 11pm-12am is a one hour period even if leap seconds cause the last minute to have 59 or 61 seconds)
- goodcanadian 9y agoWhen people talk about a day, they are usually thinking more of a solar day than a sidereal day. A solar day varies, but on average it is about 24 hours. That is after all how hours were originally defined.
- bouvin 9y agoI've always found it odd that English, which otherwise is fairly rich vocabulary-wise, does not have a specific word for this. In Danish, we have 'dag' (day), 'nat' (night), and 'døgn' (a day and a night). A 'døgn' contains all the leap seconds that may be necessary.