Re: Wikipedia article
- Original Message - From: "Ed Davies" <[EMAIL PROTECTED]> To: Sent: Tuesday, January 02, 2007 3:55 PM Subject: [LEAPSECS] Wikipedia article > Thanks to those who confirmed the ITU text on when leap seconds can > be applied. > > I've made two small edits to the Wikipedia article to correct > parts which were wrong or potentially misleading (plus a slightly > tongue-in-cheek remark in the discussion page) > > However, it's a horrible article and really needs reorganization > as some of the paragraphs have suffered serious mission creep. > > I don't even like the first sentence. "Intercalary" seems wrong > to me as a leap second is part of the day it is applied to, not > between days. I thought about changing it but decided I might > be being a bit blinkered in my definition of "intercalary". > Thoughts? > > Ed. > The French-language term for leap second is "second intercalaire", so calling a leap second "intercalary" has a linguistic precedent if nothing else. Besides, the English term "leap second" is a misnomer--a leap year is a year with an extra day in it (and the inserted day is *not* called a leap day) so by analogy the insertion of a second should probably have been termed a "leap minute". But that's all cesium over the dam, now. Brian
Re: what time is it, legally?
- Original Message - From: "Daniel R. Tobias" <[EMAIL PROTECTED]> To: Sent: Thursday, December 14, 2006 5:45 AM Subject: Re: [LEAPSECS] what time is it, legally? > On 13 Dec 2006 at 21:43, Steve Allen wrote: > > > http://gauss.gge.unb.ca/papers.pdf/gpsworld.january01.pdf > > One quibble with that article is that it gives the Global Positioning > System as an example of how humanity has been obsessed with knowing > what time it is. Actually, GPS arises from our obsession with > knowing what *place* we're at; its need for precise time is a mere > technical detail of its implementation. (Some of the earlier > historical needs for precise time also arose out of navigation, where > knowing one's position in space necessitated also knowing something > about time.) > All through this debate I've been struck by the parallels to the story of John Harrison as described in Dava Sobel's _Longitude_. Like Harrison's clocks, GPS provides both time and longitude for those with the means to process the needed information out of the raw data. And, like the 18th-century debate between astronomers and "mechanics" (clockmakers), over observational vs. synthetic means of determining position in space and time, we now have a debate between those who believe our notions of time MUST remain astronomically based and those who see more precise (and more easily managable) oscillators--cesium atoms--as being the wisest choice for current and future scientific purposes. What the outcome of this will be, and who will be interested in any of this discussion 250 years from now, remains to be seen, but the effects on future timekeeping and related endeavors will most likely be just as significant. The upshot: be careful what you say, gentlemen; someday, a descendent of Sobel's may write a book about _you_! :) Brian Garrett
Re: The fine print
- Original Message - From: Rob Seaman To: LEAPSECS@ROM.USNO.NAVY.MIL Sent: Wednesday, November 29, 2006 9:44 AM Subject: [LEAPSECS] The fine print I was rummaging around to see what web service based UTC clocks I could find for a small data-taking project. (Small project, large data, actually.) I happened to visit: http://www.time.gov/about.html and found this disclaimer: "This web site is intended as a time-of-day service only. It should not be used to measure frequency or time interval, nor should it be used to establish traceability to NIST or the USNO." During this Holiday Season (sorry, Mr. O'Reilly), I'm reminded of "Miracle on 34th Street": "Your Honor...every one of these letters is addressed to Santa Claus. The Post Office has delivered them. Therefore, the Post Office...a branch of the federal government...recognizes this man, Kris Kringle... to be the one-and-only Santa Claus! If NIST and USNO, official agencies of the United States government, declare time-of-day to be distinct from time interval, who are we to disagree? As the New York State Supreme Court rules in the play: "Since the United States government... declares this man to be Santa Claus... this court will not dispute it." Case dismissed! Rob Seaman NOAO This distinction is also recognized in the half-hourly station ID's on WWV and WWVH "...providing time of day, standard time interval, and other related information..." Brian
Re: ADASS poster on UTC
At 10:20 AM 10/28/2006, you wrote: Steve Allen scripsit: For most civil purposes time is only relevant to the nearest minute; John Cowan replied: An obvious counterexample is taping TV shows: you don't want to miss the first or last minute (modulo the presence of commercials). I go to some trouble to keep my VCR synchronized with NTP time to the nearest second or two. An obvious example is taping TV shows: you don't want to miss the first or last minute (modulo the presence of commercials). When I used to watch TV I went to some trouble to start recording a minute or so before the scheduled start time of the program and to continue recording for a few minutes afterwards. Sorry for the sarcastic looking format: the symmetry of the argument just appealed to me. Ed. Nowadays, at least in the U.S., the process of starting a show on time is further complicated by the n-second delay (usually 5
Re: IERS bull D # 94
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: Sent: Wednesday, October 04, 2006 7:49 AM Subject: [LEAPSECS] IERS bull D # 94 > Bull D came out today, Oct 4. > It says that as of Sep 28 the value of DUT1 should be +0.1 > > In this non-causal world of announcements I note that WWV is > still broadcasting 0.2. > > Does anyone have a scheme for sendlng this note to Boulder > as of last Thursday? > > I didn't think so. They must have read your email because they are now broadcasting 0.1. Only six days late :) Now we have a new illustration of the phrase "good enough for government work." Brian Garrett > -- > Steve Allen <[EMAIL PROTECTED]>WGS-84 (GPS) > UCO/Lick ObservatoryNatural Sciences II, Room 165Lat +36.99858 > University of CaliforniaVoice: +1 831 459 3046 Lng -122.06014 > Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m >
Re: leap seconds in video art
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: Sent: Monday, July 31, 2006 12:14 AM Subject: [LEAPSECS] leap seconds in video art > Earlier this year Felicity Hickson produced a work of art comprised of > 23 seconds of statements by 23 people on the 23 leap seconds since 1972. > > http://youtube.com/watch?v=GtYvSjS1jUI > You give us 23 seconds, we'll give you the world :) Interesting video, though most of the mini-lectures did imply that leap seconds compensate for secular deceleration of the earth rather than seasonally accumulated differences between UTC and UT1. Then again, anyone likely to watch this video will probably already understand the difference. Brian
Re: PT Barnum was right
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: Sent: Thursday, July 06, 2006 7:27 AM Subject: [LEAPSECS] PT Barnum was right >(gesnippt) > Finally, I've been spending a lot of time in the LA region lately. > The CBS radio affiliate in the SF Bay area broadcasts the hourly > national news spot on, and the time tone is useful for setting a > watch. The CBS radio affiliate in the LA area very plainly is using a > time compressing/FFT pitch shifting device on the live national feed. > The time tone in LA always happens around 10 to 15 seconds after the > hour. You can thank the U.S.' increasingly draconian anti-obscenity laws for that. In response to an email inquiry to KNX on this very subject (the delay I noticed was about nine seconds), I was told that the station delays their broadcast in order to enable on-the-spot editing of objectionable material. The FCC recently increased fines for violation of anti-obscentity rules, and some television stations were even fined for not censoring all 500 milliseconds of the Janet Jackson "wardrobe malfunction", so it's in networks' best interests to do this even if it means setting your watch to their time signal means being 9 seconds late. >> Somebody tell me again -- why is it thta broadcast civil time signals > need atomic accuracy? > I rather like the way James Jesperson and Jane Fitz-Randolph put it in their excellent layperson's introduction to time and frequency, _From Sundials to Atomic Clocks_: "The 'time' as most of us know it is simply inexpensive crumbs from the tables of the few rich "gourmet" consumers of time and frequency information." The guy wearing the trendy Swatch with hands pointing at a blank dial neither knows nor cares about any of the esoterica discussed on this list; for him, the time will be whatever They(tm) say it is. If that's what is meant by "broadcast civil time signals", then it's true: we're being served chronological junk food and most folks couldn't care less. Bon appetit! Brian Garrett
Re: Risks of change to UTC
- Original Message - From: "James Maynard" <[EMAIL PROTECTED]> To: Sent: Friday, January 20, 2006 9:33 PM Subject: Re: [LEAPSECS] Risks of change to UTC > M. Warner Losh wrote: > > In message: <[EMAIL PROTECTED]> > > James Maynard <[EMAIL PROTECTED]> writes: > > : M. Warner Losh wrote: > > : > In message: <[EMAIL PROTECTED]> > > : > James Maynard <[EMAIL PROTECTED]> writes: > > : > : ones position using sight reduction tables. Today a mechanical watch or > > : > : chronometer, or a battery-powered wristwatch, can be set to UTC using > > : > : radio time signals. Then when power fails, the sailor still has a > > : > : reasonably accurate spprodximation to UT1 available. > > : > > > : > If DUT1 is broadcast, then one can set the time keeping device to UT1 > > : > by a means similar to setting it to UTC, even if DUT1 exceeds 0.9s > > : > with a similar accuacy (or better). There's nothing that says a watch > > : > has to display UTC to be set correctly. > > : > > > : > Warner > > : > > > : > . > > : > > > : And how is DUT1 to be broadcast in a language-independent manner? That > > : protocol needs to be established well in advance. > > > > It already is being broadcast in, eg, WWV. > > > > Warner > > > > > > > But the protocol for broadcasting DUT1 in, e.g., WWV, does not provide > for DUT1 values of more than plus or minus 0.9 s. The value of DUT1 > could be announced by voice message -- but that would not be > language-independent. If I travel to asia in my boat, I will not be > able to benefit from DUT1 announcemnts in Japanese from JJY or in > Chinese from BPM (or whatever their standard time and frequency station > is). An longwave broadcasts such as those from WWVB do not have voice > modulation at all! > WWVB broadcasts the DUT1 correction in binary-coded decimal form, and is capable of representing DUT1 values up to +/- 1.5 seconds with their current format. I would think other longwave stations do the same, but not knowing their particular BCD format I couldn't say what DUT1 values they are capable of representing. Brian Garrett
Leap seconds anti-democratic? (Humor)
While counting down to 23:59:60, you may enjoy comedian Steve Martin's take on 2005's final moment: http://tinyurl.com/9mv4y Happy New Year! Brian Garrett
Re: Leap Second Countdown Clock
- Original Message - From: "Tom Van Baak" <[EMAIL PROTECTED]> To: Sent: Tuesday, December 27, 2005 4:45 AM Subject: [LEAPSECS] Leap Second Countdown Clock > Two pages that may be useful this weekend: > > Leap Second Countdown Clock > http://www.leapsecond.com/java/nixie.htm > > How to Watch a Leap Second > http://www.leapsecond.com/notes/leap-watch.htm > > After the weekend let me know if you have photos > or your own links to add to the above collection. > > /tvb Someone mentioned calling various speaking clocks to capture the leap second. Telco time services won't handle the leap second in real time, of course, but WWV/H and USNO should contain the telltale extra tick. Is Jim Jaeger of ClockVault.com on this list? I like his time service but there's nothing on the website to indicate how the speaking clock will handle the leap second. I believe it will, but there have been no updates to the site to discuss it (although the web clocks are working again, they weren't for a while.) Unfortunately I have to work New Year's Eve but I will try to have www.time.gov open on my destop. I suspect that its Java applet isn't up to handling the leap second though. I have tried to contact the webmaster to inquire but (understandably) I have not gotten a response. 4 days, one hour and (tick, tick, tick, bep) 46 minutes to go. Brian Garrett Brian
Re: Schreiver AFB warns about leapsec
- Original Message - From: "Tom Van Baak" <[EMAIL PROTECTED]> To: Sent: Tuesday, December 20, 2005 5:09 PM Subject: Re: [LEAPSECS] Schreiver AFB warns about leapsec > > > While you're at it let's change when leaps occur; not > > > just at 23:59:59 > > > ... > > I second this too, 23:59:59 is the worst time to > > insert a leap second, since failing to implement it > > leaves you with the wrong day (month and possibly > > year) at the very second it occurs. > > Given the way Olympics are promoted these days, > as well as stadium naming rights, billboards, web > advertising, and google adwords, perhaps the ITU > can get commercial sponsorship for future scheduled > leap second events. Commercial interests have long > since claimed trademarks on otherwise free letters, > words, and symbols. So how about time itself? > > The income could be applied as grants to those trying > to correctly implement and debug the growing global > list of time interconnected technologies. And no small > percent to astronomers so they have real-time precision > access to UT1. Everyone is happy. (If this happens I will > deny ever having suggested it). > > "Coca-Cola is the official sponsor of the December 2005 > leap second. The one second pause that refreshes." > > "Panasonic is the official sponsor of the June 2007 > leap second. Just slightly ahead of Earth time." > > /tvb "WWV...You give us 22 minutes, we'll give you 21 minutes and 60 seconds." Brian
Re: a system that fails spectacularly
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: Sent: Wednesday, December 07, 2005 7:01 AM Subject: Re: [LEAPSECS] a system that fails spectacularly > On Wed 2005-12-07T06:59:39 -0700, Rob Seaman hath writ: > > it seems that one of two things must be true. Either the fact that > > the letter is dated December 5, 2005 indicates that they just now got > > around to acting on the July, 2005 announcement of the upcoming leap > > second - or, they acted upon this in a more timely fashion and > > decided to embargo the announcement until the latest plausible moment > > at which it would be possible for their lawyers to later argue timely > > notification of their customers. > > ACR is not alone, see Saab, who announced much earlier > > http://www.transpondertech.se/node1924.asp?intContentID=3197 > > also reported by Canada > http://www.ican.nf.net/R4update.htm > And you've gotta love the interpretation of UTC as "Universal Time Code" in the Canadian report. If they don't understand what UTC is, or at the very least understand that their users are going to be confused by their misleading use of the acronym, it's hardly a surprise that a leap second is going to pull the rug off their code and expose the bugs they've swept underneath it. Brian Garrett
Re: BBC - Leap second talks are postponed
- Original Message - From: "Rob Seaman" <[EMAIL PROTECTED]> To: Sent: Monday, November 21, 2005 8:05 AM Subject: Re: [LEAPSECS] BBC - Leap second talks are postponed > On Nov 21, 2005, at 1:53 AM, Clive D.W. Feather wrote: > > > It is NOT CALLED "daylight saving" and it is NOT saving any daylight. > > > > It is "summer time". > > Ok, then. Anybody have a suggestion for a general term for which > daylight saving and summer time are special instances? My argument "Seasonal clock adjustment", perhaps? Brian
Re: BBC - Leap second talks are postponed
Well, they'll get a _little_ more time on 31 December... ;-) Brian - Original Message - From: "Tom Van Baak" <[EMAIL PROTECTED]> To: Sent: Tuesday, November 15, 2005 3:42 PM Subject: [LEAPSECS] BBC - Leap second talks are postponed > BBC News, 9 November 2005, 08:36 GMT [sic] > > http://news.bbc.co.uk/2/hi/science/nature/4420084.stm > > "Consideration of a proposal to redefine everyday timekeeping > by scrapping leap seconds - small changes made to clock > time - has been postponed. A working party weighing the > proposed change to Coordinated Universal Time (UTC) has > decided more time is needed to build a consensus on the > issue." ... > > /tvb >
Re: Precise time over time
- Original Message - From: "Rob Seaman" <[EMAIL PROTECTED]> To: Sent: Thursday, August 11, 2005 7:59 PM Subject: Re: [LEAPSECS] Precise time over time > On Aug 11, 2005, at 7:27 AM, Peter Bunclark wrote: > > > Surely the point about the slaughterhouse is the thought of the > > throat slasher getting a couple of seconds ahead of the brain stunner. > > That's what I love about this example - it just gets worse and worse > the more you try to clarify. "I see, little Sally, that you don't > fully understand what I'm talking about. You see, it is R2D2's job > to whack the steer over the head with a brain-stunner, and then C3P0 > slashes its throat to let all the blood pour out into the open trench > that flows throughout the abattoir. Watch your step now... Just > think how - messy - it would be if the throat slasher went into > action before the brain stunner! Blood would splatter just > everywhere! And the brain stunner might then miss entirely due to > the animals thrashing about in their death throws, which would make > the subsequent guts eviscerator [presumably "manned" by Pee Wee > Herman's robot from Star Tours] a real horror show. And as you > surely now see, little Sally, all of these robotical slaughterhouse > shenanigans are like totally the fault of those dastardly leap > seconds..." > > Rob Seaman > National Optical Astronomy Observatory > OTOH, wouldn't "Robotical Slaughterhouse" be a kick-ass name for a band? :) Brian Garrett
Re: so sorry, Markus
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: Sent: Thursday, July 07, 2005 11:50 PM Subject: [LEAPSECS] so sorry, Markus > Nature interviewed Markus Kuhn about the leap second and did a good job. > > UPI has turned the Nature story into an abomination; e.g., > > http://washingtontimes.com/upi/20050707-090936-2878r.htm > Yikes. I wonder if this newspaper is where President Bush gets his science information. It would explain a lot... Brian Garrett
Re: GeT
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, September 14, 2003 12:33 AM Subject: [LEAPSECS] GeT > Apparently during the Y2K hype I missed on one aspect of timekeeping > that may have been a prompting factor in starting up the leap seconds > review: > > Greenwich Electronic Time (GeT) > > The web site is supposed to be > http://www.get-time.org > and they presumably also have the domain get-time.net > but these do not appear to be operational today. > > There are records of their activity at > http://www.linx.net/special-projects/get/index.thtml > > Several members of LEAPSECS appear to have advised them. > > There are a number of online references to this initiative, most of > which appear to be reprints of the original press release in which > Tony Blair and some components of her majesty's government put their > support behind it just before the Millennium Doom opened for business. > The best review of what it was "NTP with marketing", and it seems to > have wanted to distribute UTC via a Java applet. > > Nonetheless, it appears to have died before the end of calendar year > 2000. Again judging from press coverage, this was in part due to the > fact that Internet Exploder apparently considered (and rightly so > IMHO) that changing the system clock was outside of the Java sandbox. > > http://groups.yahoo.com/group/ISO8601/message/76 gives the best summary I've seen of what the general feeeling about GeT was in the timing community roughly one year into the project. Am I correct in understanding that the GeT people actually approached Prof. Mills for help on this project? That would be like asking the inventor of the wheel to help them market a six-sided version :) Brian
Re: more media coverage
- Original Message - From: "Steve Allen" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, July 22, 2003 9:35 AM Subject: [LEAPSECS] more media coverage > CNN is broadcasting the video form of this story today > > http://www.cnn.com/2003/WORLD/europe/07/22/time.boulden/index.html > > I surmise that Mr. Catchpole was not prepared with the figures. > Technically garbled in typical CNN fashion, but at least *somebody* is paying attention. Brian
Re: timestamps on death certificates
- Original Message - From: "Kevin J. Rowett" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, June 06, 2003 8:57 AM Subject: Re: [LEAPSECS] timestamps on death certificates > Many wills and living trusts these days are written to provide > for concurrent death events of both spouses, even to the point of > defining concurrent to be within 30 hours of each other. > > KR > > > -Original Message- > From: Leap Seconds Issues [mailto:[EMAIL PROTECTED] On Behalf Of > Steve Allen > Sent: Friday, June 06, 2003 8:45 AM > To: [EMAIL PROTECTED] > Subject: Re: [LEAPSECS] timestamps on death certificates > > > On Fri 2003-06-06T07:37:57 +0100, Peter Bunclark hath writ: > > A husband has a will leaving everything to his wife, or if she dies first, > > to their children. The wife has a will leaving everything to her secret > > lover. They are together in a car crash, and are put on life-support > > systems including heart monitors. They both, sadly, die at around the > > same time; both have a last-recorded heartbeat. > > But suspecting her nature, the husband had insisted on a prenuptial > agreement that nullified her inheritance rights until the marriage > passed its first anniversary. After having tea at home with his kids, > they were travelling on their way to a second honeymoon. Their > recorded times of death were both only seconds past midnight. > > While preparing for probate some of the lawyers note that the recorded > times of death were after midnight according to the new leap-free UTC, > but before civil midnight as defined by existing statute. During the > ensuing legal discovery free-for-all other lawyers find that one of > the hospital maintenance technicians sets the clocks on the heart > monitors using new leap-free UTC, and another sets them according to > the GMT-based statute. > > After the judge awards the inheritance, the losing parties sue the > hospital for failing to maintain standard practices. > > Leap Free Civil Time: boldly going where no mysogynistic case law > fantasy has gone before. > I see the makings of a new TV series here: "Law and Order: Timekeeping Division". In episode one, things turn ugly when a terrorist threatens to blow up the firm's office by placing cesium he managed to steal from their HP5071 in the basement into the water cooler. :-) Seriously, these are,uh, interesting scenarios, but as you just pointed out and as Tom Van Baak mentioned, birth and death are processes that do not span a discrete instant such that a particular second (leap or not) should make a difference. I'm still intersted in finding out about UT1 (or UT2) being the basis of civil time; I thought we in the U.S., atavistic though we may be about switching to SI units, were at least on track with the rest of the world by making UTC the legal basis of civil time. Brian Garrett
Re: pedagogically barren?
- Original Message - From: "Markus Kuhn" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, June 05, 2003 2:33 AM Subject: Re: [LEAPSECS] pedagogically barren? > "Seeds, Glen" wrote on 2003-06-04 15:00 UTC: > > It's also true that changing to SI units for weight and volume is a lot more > > technically tractable than for length. Public opposition would still be a > > big barrier, though. > > That's what the UK have done. The imperial units of weight and volume > are not legally recognized any more in Britain (only pints are still > permitted for drinks volume), whereas inch/yard/mile continue to be > legally recognized for length and speed. > > To bring the topic closer back to the scope of this mailing list: > > One international standard related to time keeping that I would like to > advertise for is the international standard numeric date and time > notation (ISO 8601), i.e. 2002-08-15 and 14:14:57. > > Whereas both the modern 23:59:59 and the old fashioned 11:59:59 p.m. are > equally widely used in Britain, the modern notation seems to be mostly unknown > in the US outside the military and scientific communities (and the US > military seem to drop the colon as in "1800" and say strange things like > "eighteen hundred hours" instead of "eighteen o'clock"). The uniform > modern 00:00 ... 23:59 notation is now commonly used in Britain for > almost any publically displayed timetable (bus, trains, cinemas, > airports, etc.), and on the Continent they haven't used anything else to > write times for many decades. > A propos of both the topic and the discussion of notation, I've observed that in the U.S., hospitals (where 24-hour notation, or "military time" as civilians inevitably call it) are one of the few businesses where wall clocks are nearly always set to the correct time (within+/- one minute, and often within +/- 10 seconds, as checked against my WWVB watch). The correct time on birth and death certificates is important, but I was not aware of how important until I saw a posting from Prof. David Mills on comp.protocols.time.ntp in which he said that UT1 (not UTC) is the legal standard for death certificates. My reaction was that this is fascinating if true, but even if it is (I couldn't find any documentation of this), I would have to wonder how DUT1 becomes an issue if the tolerance is (as currently) less than one second? Does anyone have any firshand knowledge of forensic medical issues related to DUT1? The implications of removing the 0.9s limit are clear if Prof. Mills is correct, but my impression was that time-of-day need only be precise to within one minute for birth and death certificates. Brian Garrett
