Earth sets new record for shortest day
timeanddate.com
timeanddate.com
At least biggest cloud providers have already envisioned this [1].
> A negative leap second, if one were ever to occur, would be smeared by speeding up clocks over the 86,399 SI seconds from noon to noon.
ONE_HOUR_AGO = 60*60
Apply that to the wrong hour and... oops.
https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b...
Leap seconds are inherent to timekeeping based on the sun, which all civil time is. Without them, "midday" and "midnight" become undefined.
And it's not like allowing .9 seconds of drift is objectively correct either.
A second of drift is negligible, but a minute of drift pushes the boundaries of time zones sideways by 6086 feet at the equator.
But having the average solar midnight match that very specific spot is not important.
> A second of drift is negligible, but a minute of drift pushes the boundaries of time zones sideways by 6086 feet at the equator.
Which doesn't matter when they're 60x that size wide. Especially when countries will shift an entire time zone for fun.
A minute of drift is also negligible for civil time, as long as everyone is in sync, and we can't really predict the timekeeping future beyond that first minute of drift.
You can get a legislature to change your time zone faster than the problem leap seconds purport to solve can become relevant.
* Drift between terresterial and sidereal time,
* Drift between terresterial ground level (1G gravity mean 'surface') and orbiting satellite (eg: GPS time)
* Differing frames of time reference best suited for different tasks.
Common computer time server synced time is based on the nominal notion of "mean noontime" UTC .. or the rotation time of the earth to move from Greenwich "pointing at the sun" to again "point at the sun" (perhaps surprising to some NOT a full "360 degree" rotation as the earth has moved forward on its orbit).
Myths about time that programmers should know is a good read .. eventually drift between systems must be addressed ( GPS sats use "epoch time" (local atomic clock ticks) lapsed "per week" and GPS recievers reconcile relativistic drift using broadcast corrections ).
Any significant scientific data collection program (geophysics, astronomy) required the use of some form of "epoch time" with accurate local clocks not synced to UT | GMT | Zulu time servers.
Your apparent desire to not deal with adjustments on the order of a second during your lifetime is simply pushing the problem down the road until it's a case of reconciling hours .. or even 11 days (as has already happened in history).
> Your apparent desire to not deal with adjustments on the order of a second during your lifetime is simply pushing the problem down the road until it's a case of reconciling hours .. or even 11 days (as has already happened in history).
An hour, or fraction of an hour, is significantly easier to reconcile. Even assuming we stick with the same system for that very large number of years.
Fractions of hours require the same effort of understanding the issue that seconds do.
Where it matters (my field) we use absolute lapsed seconds in a specific framework and don't rely on sync'ing to UTC.
Fractions of hours are just a time zone. Time zone changes happen all the time. Much easier than shifting the underlying clock.
If you have a genuine interest there are some decent starting links in this thread that you might pursue.
It's actually more than a 360 degree rotation because the earth rotates in the same sense that it revolves. So the sidereal day (1 earth rotation in physics sense) is ~ 23h 56m, and the 24 hour period is over-rotation to bring the sun back into same position, and that's more than 360 degrees of rotation.
Earth does not take anywhere close to 24 hours to complete a rotation, regardless of how you measure it.
Earth rotates in 23h 56m 4s with relation to distant stars.
Earth rotates in 24h +- 30s with relation to Sun. The length of day depends on how far Earth is from the Sun, the speed at which Earth rotates the Sun changes throughout the orbit. And so every day the Sun makes a different distance around Earth (as seen from Earth), making the day a little bit longer or shorter.
And 24 hours / 365 = about 3.9 minutes of discrepancy per day.
Energy in is constant, but energy out could vary. I think the way to maximize the energy leaving the planet is to not rotate at all. The energy input would be concentrated and you would have one side very hot — and the hot side would dump the most energy back into space.
There was a short period towards the start of this year when it looked like the LoD was increasing, but that was only temporary. The decrease in LoD has been fairly consistent (apart from the occasional pause like earlier this year) for a few years, starting when the LoD was more like 1ms slower than 24h, so it was a while before the wider time-keeping community realised something weird is happening.
I am collecting various links and notes and bits of code on this and related topics at https://dotat.at/writing/time.html
See now if we'd paid a bit more attention to orienting them properly (not too late now!) we could use that angular momentum to straighten the earth's axis and thereby eliminate the scourge of winter! Or at least banish it to the benighted polar lands where it belongs.
You know, since the sun is in the southern sky then ...