What causes the unpredictability in this? I would have guessed we have earth's rotation and orbit down to many decimals. Does geological activity, weather, or something else cause rotation speed differences that we just can't predict?
In short, yes, the weather, geology, and signicantly, human movement of water via aquifer draining and dam building, as well as glaicial and ice melts, all contribute to unpredictable changes in the earths rotational period, as well as the axis of rotation. The models for this are IIRC trigonometric polynomials of fairly low order, so even if we could model the unpredictability perfectly, truncation error would limit our ability to distribute the model at super high accuracy. The existing models are built in to, eg, satellites, so you can't just make them arbitrarily complex.
Fun fact: leap seconds will stop being a thing soonish. I think they phase out in 2035, with a delay because Russia needed time to update glonass satellites.
(Note: on mobile, this is from memory, details need checking ;))
Everybody agreed that "Leap seconds" are a sufficiently bad idea that they should be replaced by 2035. Nobody has agreed how to fix it, and "Just turn them off" isn't technically legal. However, "What if there were Leap hours instead?" is technically legal and of course those hours would happen in the very distant future (likely after our civilisation is gone) so it's functionally identical to "Just turn them off" but without legal problems.
Now, I'm English, and England loves this sort of hack. You may have heard that controversial UK politician Nigel Farage "resigned" as a Westminster MP recently and that's not technically true because you can't resign, historically people hated that job and so you can't resign and we never changed that, but what you can do, and everybody does, is get assigned an "Office of profit" in which legally the King is paying you, an MP can't work for the King so you can't be an MP any more. The "Offices of profit" in question aren't real jobs† and don't pay real money, like this "Leap Hour" they'd be a legal fiction. So everybody says you "resigned" but in fact you legally can't do that...
† I mean, historically they were real jobs that made sense which is why the King paid somebody to do them, but England is very, very old so they haven't made sense for centuries and serve only as a legal fiction today.
On the subject of amusing British political legislation, should he defeat Nigel Farage in the resulting by-election Count Binface will not be able to wear his costume in Parliament; not only is business attire required in the House of Commons, it's specifically forbidden to wear a suit of armour there due to a law from the 14th century.
For those unaware, the major parties have declined to participate in the by-election triggered by Farage's resignation seeing the whole thing as a farce. As a result Farage will likely face only Count Binface, a space warrior from Sigma Six. He'd get my vote purely on the basis that he's promised to bring back Ceefax, and build at least one affordable house.
Comments like this make me really worry for the future of Hacker News. Here we are, on a seemingly informative thread, and you’ve jumped in with baseless political propaganda no doubt designed to influence the upcoming election.
His honour Count Binface is from Sigma IX not Sigma 6! To lump him in with those scurrilous, pro-littering hoodlums is the kind of anti-Recyclon smear I would associate with Sigma X’s online forums, not this place!
Between 2002 and 2013, Hartlepool in North East England elected a local football mascot known as H'Angus the Monkey as their mayor, winning three elections. I think he did ditch the monkey costume between elections, maybe Binface could do the same?
Quite a few MPs in Westminster already don't take their physical seats in Parliament (and never vote or address the House) because the conditions attached to doing so aren't compatible with their principles. Maybe Count Binface will be the next.
It's understood by constituents that a vote for a Sinn Féin representative is a protest vote that results in specifically nobody going to Westminster to represent you. I cannot imagine that any significant number of people vote for them and are then astonished when this has the effect everybody else expects.
On the other hand, Binface has not, as I understand it, ever said he would not serve if elected. He's made it clear that he's not from Clacton (or Makerfield) -- because he's a space alien -- but I believe he said if he won he would move there so that's fair enough if the constituents want him. They previously elected Nigel, and he's rarely in either parliament or Clacton so Binface can't be worse than that.
Either way, it's a contest already bringing out the sporting punters and popcorn eaters of Australia: Joke Candidate To Face Count Binface in UK By-Election
Likewise, nobody will be all that surprised, or disappointed, if Binface never takes his seat. It's much more of a protest vote than voting Sinn Féin in Northern Ireland, and voters will have achieved their aim of Farage not getting in.
Actually, I'd take issue with describing Sinn Féin as a protest vote at all. They've historically been the only choice that even claim to represent constituents in many areas. And they do seem to do much of the work of an MP (writing letters on behalf of constituents, lobbying government agencies...) they just don't vote or debate.
Agree that SF is not a protest vote but they do vote and debate. Since their first major electoral victory over 100 years ago they have been clear that they represent their constituents to the best of their abilities (I won't opine on the quality of representation in this forum). That has always involved a cabinet, votes, debates, and eventually a bicameral legislature.
The key aspect is that they consider the English government to be a foreign government and so they avoid involving it in the work that they do in Ireland for their Irish constituency. Statements about the illegitimacy of their government historically come from conservative English sources. But the fact is those SF debates in their "protest government" formed the foundation of the modern Irish state. They are a protest vote in the same way that the US Constitutional Convention was.
By the same token, they consider legislating on affairs that pertain to the English, Welsh, and Scots to be none of their business. To take up seats in a foreign parliament would be to meddle in the affairs of a foreign, sovereign nation. And that would be hypocrisy!
The thing is, an SF MP can't vote or debate because they, by policy, refuse to attend.
You're correct that the party has representatives in the other bodies which it does recognise but those aren't the same people.
So for example Órfhlaith Begley was elected MP for West Tyrone. Her voters will have known she's not going to Westminster, and she didn't - but she's not in some parallel institution instead, AFAIK there isn't one. Nicola Brogan represents West Tyrone as an MLA in Stormont, because Sinn Féin does recognise the Assembly and you can't say well but there's a body in Dublin. Dublin doesn't control West Tyrone so what would she even do there?
But Órfhlaith Begley does go to Westminster, and she has an access badge for the Houses of Parliament, and she flies over there and works in her office in the parliament buildings and answers her @parliament.co.uk emails and asks her staffers (paid for by the parliament) to respond to letters on paper headed Órfhlaith Begley MP. All the work of an MP except the most performative part.
She just doesn't go into the room which is called the House of Commons and try to speak or vote there, because the armed guards at the door won't let in anyone who doesn't swear allegiance to the King. If swearing allegiance to the King was a requirement to use the email system, then she wouldn't do that either.
More specifically, that refers to the Northern Irish MPs from the Sinn Féin party who do not recognise the UK Crown as a lawful authority in NI, and hence, refuse to take an oath of allegiance to it. (They used to not recognise the Republic of Ireland as well, until the 1980s I think.)
I think they don't approve of the Crown as an authority even if they agree it's lawfully established?
It's more like an atheist refusing to swear an oath before God in a courtroom: even if you agree that the law says you must do so, you might still not want to give God that recognition. But worse, because God might also be the defendant and the judge in this case, and you have to swear not only that He might witness your testimony but also that you pledge allegiance to Him, so swearing that oath really impairs your ability to participate in a fair trial.
For oath swearing it turns out atheists weren't why we fixed that. Some of the Christians also refuse to swear oaths. For Quakers obviously God exists - they're Christians, but a mere court of law here on Earth is no reason to go around swearing when they believe God has explicitly ordered them never to do that. They'd need orders from God, not some judge.
So for them rather than for atheists England made it possible to Affirm that you're not lying. This will work in Parliament, and it's pretty routine these days that a new member is like nope, no swearing for me, I can promise I'm not lying but I never swear or I won't swear to God.
However, Parliament does require allegiance to the King because this is a constitutional monarchy, if they wanted to be a Republic they'd get rid of the King as a group, that's not up to you as an individual member. Not much notice is taken of how much you seem to mean it about allegiance to the King, because after all plenty of members are known to hold Republican sentiments, but you are required to say the words unlike the stuff about swearing which is optional.
Binface's speculation to the media is that the Monster Raving Loony party may split the vote with Farage instead as that is closer to where his loyalties lie.
Their policies are obviously not compatible, I just don't see how that could work out for either party. Sure you could get more votes that way, but the honourable thing to do is to run seperately.
More appropiate would be the legal inability to resign from the house of commons, thus having to be appointed to a specific office of the crown which is incompatible with being a member of the commons.
There were arguments that the government should refuse Farage's appointment because he's doing it to stop the clock on investigation into his various financial dealings. While against constitutional law to decline such, it was discussed in similar situations in the past - fairly recently in fact for the same reason -- Henry Cadogan in 1842
On the subject of headwear in parliament, I quote the member for Hereford who yesterday in parliament said:
> How very different from the forthcoming by-election in Clacton, which appears to be a choice between a novelty comedy act with no real policies, and Count Binface. It is a long time since we had a count in the House of Commons, and when the time comes—as it surely will—we will have to leave to you, Mr Speaker, the delicate question of whether and how to suspend the rules on headgear in the Chamber for the new Member.
Which implies that the laws around headgear are at the behest of the Speaker.
There is precedent in electoral history for election of people dressed as a figure -- H'Angus the Monkey (a football mascott, not an actual monkey) was elected Mayor. However on the ballot paper his entry was
STUART DRUMMOND Independent
Where as Binface's is
Count BINFACE Count Binface Party
Given Farage received a mere 45% in 2024, and a unity candidate beat an incumbant mp who previosuly had 55% and was mired in a similar scandal back in 1997, it's not impossible.
How is this relevant to the current topic? I don't have any context on political stories you are discussing, but I am fairly sure that this isn't the place to do so, not at least this thread.
With all due respect, this is the kind of attitude which caused people to leave Stack Overflow en masse. We're discussing interestingly complex political procedures, this event has triggered several.
The co-ordinated universal time, UTC exists by international agreement. In the 1960s lots of countries signed a treaty so that's the "authority" AIUI.
The treaty says everybody agrees that this new standard will try to track "solar time" which felt intuitively reasonable. They want something equivalent to the old GMT which was really based on solar time, except more modern. At first the idea was, well, we just work out how fast this damp rock spins more precisely and we can use that to ensure everything works forever.
More precise measurements of the damp rock showed that, annoyingly, Mother Nature did not provide the spinning rock as a precise clock, it spins slower and faster according to a huge number of variables and so the best we can do is measure the spinning against an actual clock. So, "Leap seconds" were born to meet that legal requirement to have UTC match the solar time.
The "leap hour" would likewise fulfil this requirement, just in a deliberately useless way because we actually do not care about precisely tracking solar time. If we did, almost every human in the world would be perpetually annoyed because of course our present system of "time zones" means on average we're at least 30 minutes wrong!
Basically we guessed wrong. We thought knowing "Solar time" would be more useful than in it, and we thought these "Leap seconds" would be less trouble than they are.
It's like you buy a cat to help with your rodent problem, figuring the cat will eat mice and isn't much trouble to look after, but after purchasing a cat you find that your problem was actually rats, your cat is terrified of these large dangerous creatures and sometimes gets bitten by them necessitating expensive vet bills and now you need to pay a lot of attention to the poor animal and also now need to buy cat food.
Heh, I like the analogy but my question was really why it was considered such a hassle.
I mean we deal with daylight saving time all the time and I know it's not the same because the leap second affects UTC, not just local time zone, it's just that you are either dealing with monotonically increasing time like epoch, or you are dealing with "human" time and I found no distinction in the latter.
Is it "just" that leap seconds or delay seconds caused problems in epoch to utc conversion? Note the just in quotes, but did I just answer my own question? :)
It's a hassle for anybody doing or recording "physics" as they cannot log against UTC (which may or may not have an added second or removed second in some interval if it happens to overlap the adjustment zone).
Those things that really do rely on actual "elapsed time" rather than the difference between two recorded "book times".
Does this happen? Yes, a few times in my career in geophysical exploration - it's why multiple bits of gear are synced to a reference "real clock" which gets logged against the raw GPS epoch time (real time since Sunday last week(?)) and processed "UTC" time (some variation of it).
The most annoying part is that a lot of GPS gear automatically "corrects" to UTC without giving clear indication of it. Things would'be been fine if the standard was to explicitly sent out TAI timestamps, with a leap second offset for the people who insist on UTC.
Well, yeah, that to - although TBH it's never been an issue in my line of work which started with (LORAN actually, and then moved to..) off book reverse engineering of the OG NavStar format. To this day it's still "raw" GPS packets that are logged - and later post processed for greater accuracy (and often blended with a local area fixed position base stations "corrections" for GPS fix wobble).
There's a lot of fiddly pedantic stuff that goes with scientific data recording, timekeeping is but one domain of possible issues.
It's not solving a very important problem and the edge cases it introduces makes software more complex and bug prone
If the world weren't entirely reliant on software to the extent it is today (like when leap seconds were introduced in the 70s), it wouldn't matter as much.
This seems like an interesting solution, even if it's absurdist at first thought. What if we just shift the steel bar in Greenwich 20 metres east or west instead of adding a leap second?
Then everything would theoretically be correct. The logical next thing to do would be to move all the time zones as well. But time zones already don't coincide with the lines of longitude in practice; they tend to follow country or internal boundaries somewhat close to the lines of longitude (but sometimes multiple hours away!). After a few thousand leap seconds, maybe one or two countries would feel it was helpful to readjust a time zone boundary to better align with solar time, but in practice this would never be the overriding reason for that decision.
You say people's GPS systems would all suddenly be wrong because they depend on locations in latitude and longitude? I don't think this is a problem either: in practice longitude and latitude are given not relative to the steel bar in Greenwich, but to per-continent geodetic datum points. This already prevents continental drift from affecting your coordinates, though a big earthquake can still mess things up.
It's caused significant controversy in my (former colony) country where all other long-term leases are 99 years. The landowners are insisting that their ancestors were cheated and they want their land back.
Everybody agreed that "Leap seconds" are a sufficiently bad idea
No. Not everybody. I prefer accurate time, and all the complaints I've heard hold little water.
My servers need to timesync forwards and back all the time, eg timedrift. They need to jump to new times, or slowly drift, depending.
VMs can be hypervisor starved, or need to move to a new host.
Servers also need to handle missing time. Any daemon or program which cannot handle this is buggy, broken, and needs to deal.
Leap seconds are just part of all of this, and present no new issues compared to normal time change. I question the capabilities of any engineer who singles out time second as difficult to deal with, time is constantly changing on servers. Constantly.
So back to the start, no... everybody doesn't agree. Google isn't "everybody".
Accurate to what though, and for what? We decide what the standard is, and it seems like it would be a lot easier to have accurate time if we aren’t adding or subtracting seconds here or there. Does it really matter if the sun crests the horizon a second earlier than it did ten years ago? If it does, isn’t it much easier to just adjust your sun-cresting time?
There's a long tradition in the UK of having electoral candidates who don't expect to win but run because it's free publicity in a high profile race. "Count Binface" is a comedian who dresses up as a space alien whose outfit resembles well, having a Bin for a face. The serious political parties told Nigel to fuck off, if he wants to step down and then immediately contest the same seat they wouldn't run against him in this farce, but Binface isn't a serious politician so he is running in that by-election.
Nigel wanted to be able to do this whole thing about how the establishment is rotten and he (Wealthy public schoolboy who keeps lying to people and doesn't bother going to Parliament even though he was elected to do so) is a true man of the people and can put things right. It got him this far in life. But with the other candidate on your ballot being a space alien it's obvious which of these options is really "the establishment" and it's not the guy whose policies include "Building at least one house†" and who says he comes from a different planet...
† British political parties often insist they will build lots of housing because that's popular with voters. But, in practice they don't tend to really deliver because the various groups lobby not to actually build. So "at least one house" is a joke about this phenomenon, while conveniently also being technically possible, Binface could just build a house, that's a thing you can do.
I think it's more than publicity. Anyone can stand as a candidate, and anyone can vote for them. Money and connections and establishment and everything else don't matter, all candidates are equal on that stage. It's both weird and to be admired.
Nigel Farage has decided to counter a scandal by throwing himself upon his constituents for judgement, the obviously establishment parties have backed off to allow Binface to run against him in a ~1v1, and you think Binface is more anti establishment than Farage?
Yes, the MP, former MEP, and founder of a significant political party is closer to being “the establishment” than the comedy candidate dressed up as a rubbish bin.
The ex stockbroker who lunches with presidents and takes £5m personal bribes in charge of a party sticked with ex ministers of the crown (at least one who took a bribe) is clearly not the establishment.
A frightening fact, the 2011 magnitude 9.0 Tohoku Earthquake shifted the position of the Earth's figure axis about 17 centimeters, making days about 1.8 microseconds shorter.
> The models for this are IIRC trigonometric polynomials of fairly low order, so even if we could model the unpredictability perfectly, truncation error would limit our ability to distribute the model at super high accuracy. The existing models are built in to, eg, satellites, so you can't just make them arbitrarily complex.
What are the satellites doing with the models? They're not deciding leap seconds on their own, I hope. So I don't see why the leap second decision would be locked to low accuracy.
Also I would expect doubling the precision to give you a 3-4x slowdown on the math or adding orders to have less effect, and the amount of available computation spent on those models to be like a tenth of a percent at most, so the extra cycles wouldn't be an issue. What am I missing here?
To me it seems like unpredictability is the only real issue.
> because Russia needed time to update glonass satellites.
Why is this? As leap seconds don’t occur on a regular frequency, I assume they are not hardcoded on the software or hardware on board, but the control centre uploads them on the satellites enough in advance once they have been scheduled. So why can’t the control centre just stop sending those updates?
My understanding the problem is that GLONASS is aware of leap seconds at all. It sends messages in UTC, which has this leap second funny business. GPS uses a special "GPS time" (sometimes abbreviated UT) that doesn't have a leap second. For further confusion, the leap second ensures that UTC is never more than 0.9 seconds off of mean solar time, aka UT1.
This type of assumption that was made early in a massive software and hardware project that's now been ossified for ~50 years is going to be hard to change.
Yes, all of those and more. Our measurement precision is much better than the year-to-year first and second derivatives of day length. https://datacenter.iers.org/singlePlot.php?plotname=Bulletin... has the most relevant plot to this; the vertical jumps reflect leap seconds. (IERS has other plots for other dimensions of rotation, but I like this one.)
Seems like the seasonal change in June-October increased
My best guess would be it's somehow related to water distribution? More water going into the atmosphere? Glaciers growing (unlikely)? Did multiple huge water reservoirs go into service and get filled up over the summer months?
Since I was checking the Wikipedia article anyway (for when the last leap second was inserted), it also has an answer for this:
"Because the Earth's rotational speed varies in response to climatic and geological events, UTC leap seconds are irregularly spaced and not precisely predictable."
Quite the opposite. The earth's rotation can vary by quite a few seconds each year. But over hundreds of years, the variations mostly cancel out, which is why I think trying to add or remove leap seconds are a bad idea. The only people who care about such things are space agencies, and they can apply whatever offset they want, it doesn't need to affect everyone else.
Arguably, the only real-world impact this drift has on normal people is GPS, but GPS already transmits an offset from its own clock so that receivers can correct for that. The GPS clock is different both from UTC and TIA.
I don't think we know this do we? we haven't been measuring accurately enough for long enough to be confident that it does in fact cancel out. In fact for the period of time where we've been applying leap seconds they were happening with significant frequency and always in the same direction. It's only been very recently that there's been the realistic suggestion it might drift in the other direction.
If anything people have been suggesting that if we do get rid of leap seconds that we can just wait until the offset is enormous instead (say an hour) because it would take a very long time to happen. But even still, that does actually affect everyday people (because people would surely notice when solar noon is an hour later/earlier). Although pragmatically the obvious solution there is to change timezone instead.
Among other things, turbulent currents of liquid iron in the Earth's core can make the core drift eastward or westward, which causes the crust and mantle to turn slower or faster. Same thing with the strength of the jet stream.
