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The leap second’s time is up: world votes to stop pausing clocks

nature.com

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Re: The leap second’s time is up: world votes to stop pausing clocks

#41

Post by mjevans »

euroderf wrote: post #16

Hot take: Leap seconds caused by astronomers refusing to modify their own software, instead getting the rest of the world to modify theirs. Too facile?

Doesn't astronomy already use their own time reference standard?

It seems like JPL (NASA) and the scientific community have defined two currently used sets of time standards for observations from Earth and from space near Earth. https://en.wikipedia.org/wiki/Time_standard#Time_standards_f... Barycentric Coordinate Time (TCB) and Geocentric Coordinate Time (TCG) with DE430 as the current revision of their standard https://en.wikipedia.org/wiki/Jet_Propulsion_Laboratory_Deve...

Re: The leap second’s time is up: world votes to stop pausing clocks

#42

Post by orra »

ajkjk wrote: post #7
TEP_Kim_Il_Sung wrote: post #5

Earlier quoted context omitted.

So not the world? Title is misleading.

It's a totally valid synecdoche. "The world votes..." doesn't mean "every human on earth votes...", it means "a worldwide body votes...".

Quite, although even “every human on earth votes” isn’t the most literal interpretation: the planet becoming sentient and itself voting would be.

Of course, that’s an absurd interpretation.

Re: The leap second’s time is up: world votes to stop pausing clocks

#43

Post by kangalioo »

Hamuko wrote: post #33
bilsbie wrote: post #29

Can anyone explain what the alternative is? Surely we won’t just get more and more out of synch with the earths orbit? Also why does it say the earth is slowing down but this year it sped up. Sounds quite impossible?

> Surely we won’t just get more and more out of synch with the earths orbit? Why does being out of sync with the Earth's orbit matter?

Because humans use time as an indicator for day and night

Re: The leap second’s time is up: world votes to stop pausing clocks

#45

Post by gricardo99 »

SamBam wrote: post #22

> Leap seconds aren’t predictable, because they depend on to Earth’s natural rotation. This is surprising to me. Is the Earth's rotation so arbitrary?

It would surprise me if we could not measure and detect any variation in the earth’s rotation. A leap second is on the order of less than 0.000001% variation, at least according to the leap seconds applied recently.

Re: The leap second’s time is up: world votes to stop pausing clocks

#46

Post by dmm »

euroderf wrote: post #16

Hot take: Leap seconds caused by astronomers refusing to modify their own software, instead getting the rest of the world to modify theirs. Too facile?

More like lazy programmers want everyone to change basic timekeeping practices just so they don't have to fix their code.

Re: The leap second’s time is up: world votes to stop pausing clocks

#47

Post by bewaretheirs »

throw0101a wrote: post #9

> How, and whether, to keep atomic time in sync with Earth's rotation is still up for debate. […] > The CGPM — which also oversees the international system of units (SI) — has proposed that no leap second should be added for at least a century, allowing UT1 and UTC to slide out of sync by about 1 minute. But it plans to consult with other international organizations and decide by 2026 on what upper limit, if any, to…

The drift is sufficiently slow that you can fix it with a "leap hour" when needed -- perhaps once every five thousand years. This could be handled for civil/local time via an adjustment in the timezone definitions (something which happens a few times a year today), leaving the underlying UTC timebase unchanged.

Re: The leap second’s time is up: world votes to stop pausing clocks

#48

Post by 4str0n0mer »

euroderf wrote: post #16

Hot take: Leap seconds caused by astronomers refusing to modify their own software, instead getting the rest of the world to modify theirs. Too facile?

Very much so.

Look at astronomical software, e.g. xephem. There will be a "clocks" tab that displays a number of different clocks, TAI (atomic clock, no leap seconds), UTC (global civil time), media solar time (GMT, which ISN'T UTC) and finally, derived from the aforementioned "sidereal time", which is the one you really need to adjust your telescope. Sidereal time is derived from a year with 1 more day basically, because the earth moving around the sun adds 1 more rotation of the background stars. Which is a drift of roughly 4 minutes per day.

https://en.wikipedia.org/wiki/Sidereal_time

Oh, and then there is stuff like Julian date which you need to look up the myriads of catalogues and tables you need for corrections because everything "wobbles" even more than you'd think.

Yes, dropping leap seconds will remove 1 table lookup from the above. But astronomical time systems are so complex that that change is a drop in the ocean.

Re: The leap second’s time is up: world votes to stop pausing clocks

#50

Post by adamsb6 »

Currently software has to be built to accommodate leap seconds. They happen frequently enough that you'll find out within a few years whether your software breaks when time suddenly skips forward or backward.

If we kick the can down the road such that eventually we'll need to add a leap minute, we're going to end up with software that was never written to expect time to change in such a way, hasn't had a real world test of the change for decades, and will have no one working on the software who ever had to deal with such a change.

It's going to be much worse for software reliability to have a leap minute on the order of once a century than a leap second every few years.

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