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U.S. Scientists Call for a Time Change
saqmaster writes "The BBC reported yesterday that U.S. scientists want to change the current system which keeps clocks in sync with solar time by adding a leap second every 18 months or so. This has rattled a few cages with the scientists and operators involved in GMT-related projects and facilities as it would effectively remove the importance of the meridian from timing. "
No, really, it is about time.
If "disco" means "I learn" in Latin, does "discothèque" mean "I learn technology"?
From the article:"They want for the first time in history to separate us from the natural rotation of the Earth, which means as the years go by we will increasingly get out of sync with astronomy and the real world,"
In other news, residents of Kansas experienced a timeshift, time going back to 1213 AD.
It takes a man to suffer ignorance and smile
Be yourself no matter what they say
Just call it stardate, everyone will love it. Well, everyone here, anyway.
Only three things are certain; death, taxes, and apocryphal quotations - Ben Franklin.
Since this is a "world" resource, time should no longer be managed by the UK, but by the UN standards body. Surely this will be a much more equitable and fair solution than hogging all of the world's time by one nation.
(Near as I can tell, it's either a tit for tat for the internet thing, or Verizon and SBC have ponied up some big lobbyist dollars to save themselves a few seconds of headache every few years (ha) )
This post brought to you from the Kansas Board of Edumacation.
If brevity is the soul of wit, then how does one explain Twitter?
Why not just forget about time zones, day light savings and create a new universal global time. So what if it makes my 8am-5pm job change to 1am-9am or if it means I eat lunch during the night. It just seems like we are slowly outgrowing the need for this, as many people work normal hours that used to be considered odd (such as graveyard shifts)
Ave Molech Setting
A WHOLE EXTRA SECOND EVERY 18 MONTHS, I can do SO much in a second, like, wow, get about 2 extra keystrokes in to a Slashdot comment! This is so exciting, but seriously, this is news? Am I just crazy or does this have a significant importance on my M$ bashing life?
What the US scientists are suggesting is that we ignore the earth's rotation in our time-keeping, and just try to keep roughly in synch by arbitrarily adding leap-seconds (as opposed to adding them based on our actual observation of the slowing of the earth's rotation). i.e.: Noon will be when your shiny digital watch says it is, not when the sun is precisely above the prime meridian (or precisely X.X hours plus or minus from said event, depending on your timezone).
Dumb, dumb summary... the UK is defending the idea that humans (of both the blow-joe and the astronomical sort) base their sense of time on the earth's rotation... and so our method of time-keeping should do so as well.
God... what a dumb summary...
Akarsz Magyar Gentoo fórumot? Akkor
Like tinyurl, but one letter less! http://qurl.co.uk/
UTC or coordinated universal time (UTC is the acronym that was agreed on because the british and the french had a disagremment about the word order)is the standard time for the world. a time zone is 15 degress of longitude, and is equal to 1 hour. thus if you know the local time, and have a 0 point (Grenwich meridian) and can do some math, you know where on the planet you are.
UTC was agreed upon by an international body, many many years ago. it is now frowned upon to call it gmt (though pretty much everyone does)Not everyone follows it, and their are many variations (Newfoundland time - 30 minutes off)
some countries still have their own meridians.
time is tied to geography.
They were "spinning". By the time you got to the actual proposal, you already had a tainted opinion of it, only to have them tell you that the scientists in question don't want to comment about it.
It was a rather heavy handed approach to it, I might add.
Mod me down with all of your hatred and your journey towards the dark side will be complete!
Takes some getting used to, but when you are traveling across that country by train, it is *mighty* convenient
Um did you actually read the link you posted? That story is talking about a group of US scientists wanting to eliminate leap seconds and replace them with leap hours that are extremely far apart. This issue is just wanting to standardise the delay between leap seconds.
For a pretty full understanding of what is happening, what has happened, and why, see history of the effort, implications of change, definition of terms
Why are you attacking Kansas? We are good God Fearing Christians who are carrying out His Will. I honestly do not get why some people feel the need to persecute Christians. At least you people aren't using lions.
Yes we do. There will be one this year. The hourly 'pips' on BBC radio will get an extra pip at 2006-01-01 00:00:00.
Man, I'm really looking forward to the extra sleep!
I would disagree.... The problem with the current system is that numbers get passed around without the frame of reference, with the tacit assumption that it is known. So, when I say it's "5pm", it's like saying, "the temperature is 13" or "the wind speed is 49". 49 what? Using a timezone suffix (3pm PST) provides the necessary and sufficient information, but still requires extra knowledge to do the math -- what is the time difference between PST and where I'm at right now? It doesn't help that daylight time gets turned off and on, so you have to remember which "mode" you're in, but your wristwatch doesn't tell you at a glance. Using a numerical timezone delta (5pm GMT+5) provides the necessary information in a convenient manner. But, at that point, we might all as well just use GMTs.
The first half of the article is very parochial - kind of ooh the nasty Americans want to diminish the importance of Greenwich.
Which seems to be simply the delusion of the author, and has nothing to do with the subject of the discussion. The author has cast the entire thing as a US versus UK contest, with the noble UK scientists defending the importance of Greenwich, and the evil US overlords trying to steal it away and disrupt the lives of the common folk. First of all, I think if you polled US scientists, you'd find the vast majority of them quite content with the current system, and not calling for any change. In fact, you have to read halfway down the article to find out that the only people proposing a change are "US members of the International Telecommunications Union", without specifying which company they are referring to. Then somehow a handful of people at a telecommunications company issuing a proposal is amplified by this author to represent all US scientists and the views of Americans in general.
This is just a classic case of crappy sensationalist reporting.
Why dont we all take out our photon drives (laser pointer) point em westerly and fix the real problem?
The problem is that you don't know in advance when http://hpiers.obspm.fr/International Earth Rotation Service (IERS) is going to introduce another leap second. They monitor Earht roration and could do it with only 6 month notice. The latest leap second was anounced this summer and we had to spend few weeks to add it to our data files and test the app before the release. If we had a release a month earlier we would not have included it and it would result in a small, but unacceptable errors unless users upgrade our software. It basically means that there is no way to build an embedded software and leave it running disconnected from anything and maintain high time accuracy at the same time. You either have to create a system for automatic updates of code and data, or rely on human operator to make changes. Both methods introduce unnesessary risks and inconviniences.
Intead of saying, it 8:00 here, what time is it in Hong Kong.
You would say "We get to work at 1:pm, what time to people in hong kong go to work??"
thus still doing the same math.
Exactly, so for purposes of working out whether it's a reasonable time to call someone around the other side of the world, things would be exactly the same. No better and NO WORSE.
But for other purposes we would get major advantages. If I tell you that I plan to call you at 8:00 am tomorrow then you only have to worry about whether that's a convenient time for you, not whether I mean my time, your time or someone else's time. If I post on my web site that a major announcement will be made at 12:00 midnight tonight then everyone would know when it would be - again no need to worry about time zones. If I know the departure time for a flight and the duration of the flight then I would be able to tell the arrival time without worrying about time zones, or if I knew the departure and arrival times then I would know the planned duration.
Time zones make things more complicated with no real advantages.
To summarise the summary of the summary: people are a problem. ~ h2g2
Stop being singularity stupid! The answer is not to change what kind of ridiculous single day derived counting system to use, but to abandon the brainless lie of singularity and embrace the truth of nature's harmony, the 4 simultaneous day Time Cube!
That's Bigboo TAY! TAY!
You would say "We get to work at 1:pm, what time to people in hong kong go to work??" thus still doing the same math.
This seems like something that only people that don't play internationally think is a problem. It doesn't matter when they get to work. If the meeting is at 84:25 Global Time, then they will either be there, or they will request a time change. I couldn't care less if I schedule something at high-sun where I am and it is dawn, dusk, or some other time elsewhere. If they aren't going to be in the office, they suggest an alternate time.
This is much simpler than the current system. Ever have a conference call with people in 4 or more timezones? "We'll get back on tomorrow at 4." "Wait, is that East, Mountain, Hawaii, Alaska, or Pacific?" "Um, how about your time?" "Who said that, are they in East Coast time?" "No, Mountain." "Ok, so that's 4 p.m. Mountain tomorrow" "Wait, that's like 6 p.m. East, can we move it up a little?" and so on and so on. Then, when you finally get off the call, you have to do the math yourself anyway to figure out the local time and mark you calendar.
Yes, I have done business internationally, and I deal with people outside my time zone more than within my time zone. It would be much easier to have everyone work of Zulu time or somesuch. But, it doesn't matter if that's what I'd prefer, for if everyone else doesn't know what Zulu time is, they can't use it. But the simple fact is that it would have greatly reduced my math, not increased it or kept it the same.
Learn to love Alaska
Programmers of astronomical software already have trouble enough:
- The year -1 is followed by the year 1
- 4.10.1582 is followed by 15.10.1582, because only then the length of a year was measured with sufficient accuracy. The new system of leap years will only need a fix of one day in another thousand years.
- Last century Ephemeridical Time (ET) was introduced to serve as a constant measure of time (in contrast to the Universal Time (UT)). The commonly used time is UTC, which is running with the same "speed" as ET and being corrected every once in a while, when (UTC-UT) becomes greater than 0.9 seconds. Astronomical software has to know UT as well as the difference ET-UT: The positions of other planets have to be computed with ET and the rotational angle of the earth with UT.
ET-UT is more than 60 seconds at the moment already. Replacing UT/UTC with ET-60 s will not really make things easier and it will deprieve the old system of its benefits! If someone needs a ET-clock for doing satellite navigation, he shouldn't force everyone else to do so as well. If the U.S. scientists keep pushing, I'll switch to a russian time-server in the future.Q: Why did the Roman coliseums go broke?
A: The lions ate up all the prophets.
BBC article completely misses the point. The international time reference, since the 1950's, has been UTC, and used tuned according
to atomic clocks, not the earth's rotation. There are time references used specifically for astronomy, such as sidereal time, solar time, etc... (http://en.wikipedia.org/wiki/Sidereal_time) There is absolutely no reason why astronomical time references have to match precisely to the time reference used by normal people.
The problem is that, today, there is no algorithm for knowing when to insert leap seconds ahead of time, which means you cannot calculate any time accurate to the second which is more than 18 months in the future, because you have no idea whether or not they will decide to insert a leap second. Nor is there any algorithm, other than a table of the known values to determine when to insert leap seconds. Add that they used to add them in June in some years, and December in others, and sometimes had two in the same year, and you get a feel for how chaotic it is.
Accumulate these differences over twenty years, and you have a serious problem. That is why the global positioning system uses it's own time reference, which has no leap seconds. When you're calculating position based on propagation delays, leap seconds are a mess. so GPS time is currently (http://tycho.usno.navy.mil/gpstt.html) fourteen or fifteen seconds different from UTC. (how many leap seconds since 1999? no way to calculate, you just have to know.) Seconds are the basis for all computer based time scales. These little nudges make very little sense. It would be far smarter to insert a leap minute, every... oh... 90 years. Or make the leap second insertion an algorithmic event, and not some random decision negotiated among a committee of astronomers.
It basically means that there is no way to build an embedded software and leave it running disconnected from anything and maintain high time accuracy at the same time.
1 second is 18 months is 21 parts per billion.
If your clock needs to drift less than one second in 18 months, then you're already using an atomic clock or primary or secondary time source. This means that you are also going to go to the trouble of synchronizing your clock with some external standard that is, eventually, a primary clock.
If you can't get the leap second information from your primary time source, then it doesn't matter if you lose 1 second over 18 months - unless you have an atomic clock on board you're going to drift that much in shorter than 18 months. If you have a cheap atomic clock you may still drift that much.
-Adam
You can't maintain a highly accurate clock without external synchronization. Why doesn't your external synchronization source include leap-second information (including when the next one is going to occur, as soon as it is known)? It's no more error prone than having the clock data itself be wrong.
The application itself should be tested against leap-seconds, there's no reason you should have to test to see if a particular leap-second is going to cause a problem (just as you don't have to test it for each time the clock rolls over from 23:59:59 to 00:00:00). You add ONE LINE to a leap-second file, if you did it right, or just let NTP do it for you if you did it even more correctly.
Note that the NTP epoch implementation is itself arguably done incorrectly. A reasonable kernel can handle it better by having the NTP daemon update a leap-second file, keep a fixed Unix epoch and correct to UTC in the libraries while keeping a constantly running clock going.
"is a time service that transmits from Boulder Colorado"
As a resident of Fort Collins, CO and (now) Boulder, CO, let me clarify:
WWV transmits from Fort Collins, CO on 2.5, 5, 10, 15, and 20 MHz. You need a shortwave radio to pick it up (though, in the Fort Collins area, you can pick it up on a crappy AM radio tuned to the upper end of the band).
NIST is located in Boulder, CO, and it serves as the frequency and time reference for the atomic clocks in Fort Collins.
WWVB is also transmitted from Fort Collins, CO, providing a digital time service for radio-synchronized clocks. If you care about having the right time, these are a cheap way to get it.