Re: what should a time standard encompass?

2003-01-27 Thread Rob Seaman
to the UTC standard. If there is an actual proposal to go with this no new leap second notion, let's hear it - hopefully it will be better conceived than the surveys that have been so narrowly worded and disseminated. Folks, this isn't just some obscure technical question. Rob Seaman National Optical

Re: What problems do leap seconds *really* create?

2003-01-29 Thread Rob Seaman
are discussed very prominently in a very short document. Rob Seaman National Optical Astronomy Observatory

Re: NASA GMT vs UTC

2003-02-16 Thread Rob Seaman
potentially incur huge costs for remediation of, as yet, completely unquantified risks. Rob Seaman National Optical Astronomy Observatory

Re: Torino meeting and implications of international time UT1

2003-06-06 Thread Rob Seaman
a conclusion that Leap seconds must die! that was already formed prior to Y2K. Rob Seaman National Optical Astronomy Observatory

Re: more media coverage

2003-07-23 Thread Rob Seaman
about leap seconds. Many will - and the number of users and their applications (meaning people, their jobs and what they do in their private lives) who do care will grow as civil time and UT1/GMT diverge. Y2K had a razor sharp deadline. L2K (or L3K?) is a timebomb with a slow burning fuse. Rob

Re: more media coverage

2003-07-23 Thread Rob Seaman
- and definitely should not be avoided due to the potential for worldwide Y2K-like disasters. Go ahead, cut the Gordian knot. Rob Seaman National Optical Astronomy Observatory

two world clocks

2005-01-20 Thread Rob Seaman
discussions among biased insiders. It ain't your clock - it's *our* clock. Rob Seaman National Optical Astronomy Observatory

Re: two world clocks

2005-01-20 Thread Rob Seaman
changes are needed is no surprise (see http://iraf.noao.edu/~seaman/leap for my analysis of the situation), but what the hell is the hurry? Rob Seaman National Optical Astronomy Observatory

Re: two world clocks

2005-01-20 Thread Rob Seaman
Time (of whatever flavor). Universal Time was to be reserved for timescales synchronized to the rotation of the Earth. One might wonder at the reluctance of proponents to follow through on this easily comprehended consensus. Rob Seaman National Optical Astronomy Observatory

our customers' needs

2005-01-26 Thread Rob Seaman
there be for truncating the discovery process for uncovering similar requirements placed on civil time by the great religions of the world before making a large change in the definition of civil time? Rob Seaman National Optical Astronomy Observatory

Re: GMT - UTC in Australia

2005-02-23 Thread Rob Seaman
this was the case or not, the wording of the quoted article makes it clear that UTC is being sold to everyday Australians in its original sense of being a continuing approximation to GMT: UTC is adjusted to remain consistent with GMT using leap seconds every 18 months. Rob Seaman National Optical

Re: GMT - UTC in Australia

2005-02-24 Thread Rob Seaman
: Call the new system of time resulting from the leap hour proposal International Time, TI for short. Walk through the front door of the world's parliaments and legislatures and attempt to sell TI as a high priority proposal. What would be the likely response? Rob Seaman National Optical Astronomy

Re: GMT - UTC in Australia

2005-02-24 Thread Rob Seaman
of Universal Time. UTC is a useful approximation to GMT. Keep it that way and call any new system of civil time that might win the day something else. It is the height of intellectual dishonesty to do otherwise. Rob Seaman National Optical Astronomy Observatory

new beginning

2005-08-03 Thread Rob Seaman
be disregarded - I will. Rob Seaman National Optical Astronomy Observatory

Re: Precise time over time

2005-08-10 Thread Rob Seaman
unilaterally changing a 120 year-old international standard. Duck and cover! Rob Seaman National Optical Astronomy Observatory

Re: Precise time over time

2005-08-11 Thread Rob Seaman
discussions) simply regroup, withdraw the current silly proposal and define a process to patiently and prudently reach a consensus. It will take time to make time - better. Rob Seaman National Optical Astronomy Observatory

Re: Precise time over time

2005-08-11 Thread Rob Seaman
[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

Re: Precise time over time

2005-08-12 Thread Rob Seaman
- it is infrastructure that we must include in our planning. Rob Seaman National Optical Astronomy Observatory

Re: Precise time over time

2005-08-12 Thread Rob Seaman
are in this situation. Any civil time proposal that does not include an analysis of instrumentalities is void of meaning. Rob Seaman National Optical Astronomy Observatory

decision tree for civil time

2005-08-13 Thread Rob Seaman
evident. Please help me to remove these and to avoid adding any of your own. The structure is also too flat - categories might benefit from hierarchical nesting. Rob Seaman National Optical Astronomy Observatory

Re: decision tree for civil time

2005-08-13 Thread Rob Seaman
I've incorporated Poul-Henning Kamp's good suggestions as follows:I would have thought this would be:          1) correction issued as table          2) correction issued as formulaI think that's an orthogonal category called "corrections".  Updates to the table or formula can still occur on

Re: decision tree for civil time

2005-08-14 Thread Rob Seaman
of the variables jointly. It is also quite likely that more than several solutions will be identified that are near optimum in such a fashion. Rob Seaman National Optical Astronomy Observatory

Re: decision tree for civil time

2005-08-14 Thread Rob Seaman
On Aug 14, 2005, at 4:11 AM, Ed Davies wrote:Could come under "other" perhaps but millisecond steps are worthlisting explicitly.  At least, that's how I assume the epsilonscheme would be implemented.These options are meant to describe civil time, not timekeeping in general.  To permit fixed size

Civil Time decision tree v0.5

2005-08-14 Thread Rob Seaman
Revised and rearranged.  Decided a version number was prudent - v0.5 since I figure we're half way there.  Reminder - the intent is to provide a scaffolding for characterizing any possible civil time standard (whether practical or not).Rob SeamanNational Optical Astronomy Observatory---I)

Re: Civil Time decision tree v0.5

2005-08-17 Thread Rob Seaman
the equation might provide both astronomers and timekeepers (only two of the many stakeholding communities, of course) enough common ground to build a new civil time infrastructure. In the absence of a consensus for change, the default decision should remain, of course, to retain the current standard. Rob

Re: Consensus rather than compromise

2005-08-29 Thread Rob Seaman
to convince the politicians to vote against it? We'd have more luck legislating against the transfer of angular momentum from the Earth to the Moon... Rob Seaman National Optical Astronomy Observatory

Re: Consensus rather than compromise

2005-08-29 Thread Rob Seaman
to the mean solar day length. (And I'm doubtful that any of us would want to live on a planet or in a society for which this assertion was false :-) With no sense of irony - thanks for the excellent discussion. Rob Seaman National Optical Astronomy Observatory

Re: Consensus rather than compromise

2005-08-30 Thread Rob Seaman
in the previous message. Rob Seaman National Optical Astronomy Observatory

Re: Consensus rather than compromise

2005-08-31 Thread Rob Seaman
. It isn't sufficient for any of us simply to claim that our own pet proposal has no negative ramifications and to leave it at that. Rob Seaman National Optical Astronomy Observatory

Re: Consensus rather than compromise

2005-09-01 Thread Rob Seaman
and Calcutta, wish to be consulted and advised? Rob Seaman National Optical Astronomy Observatory

Comments on Civil Time decision tree

2005-09-23 Thread Rob Seaman
and hide the effect for most purposes (ignoring the gawdawful expense to astronomy), but is cheating really what the precision timing community wants to do? It may be annoying that Mother Earth spins irregularly, but spin she most certainly does. Rob Seaman National Optical Astronomy Observatory

Re: Comments on Civil Time decision tree

2005-09-26 Thread Rob Seaman
would reject the current proposal if anybody had thought to ask them about it. Rob Seaman National Optical Astronomy Observatory

Re: Comments on Civil Time decision tree

2005-09-26 Thread Rob Seaman
On Sep 26, 2005, at 11:56 AM, Poul-Henning Kamp wrote:Again: merely trying to point out that the "only one timescale" argument Rob pushes doesn't work.This misrepresents my position.  There are clearly many time scales for many purposes.  One of those purposes is something that might be referred

Re: Comments on Civil Time decision tree

2005-09-27 Thread Rob Seaman
Perhaps I might expand on some of Bill Thompson's statements in the context of the great convenience factor of using the current UTC standard.The accuracy requirement for the delivery of UTC to the instruments is +/- 0.410 seconds.High quality, cutting edge science doesn't always require

Re: Be thankful for John Flamstead

2005-11-10 Thread Rob Seaman
of astronomy professor, Fr. Edward Jenkins, was fond of the fourth Astronomer Royal, Nathaniel Bliss. He recalled (often) having seen a beer mug with the gent's face on it and the motto, This is Bliss, if bliss on Earth there be. Rob Seaman National Optical Astronomy Observatory

Re: a system that fails spectacularly

2005-12-07 Thread Rob Seaman
On Dec 6, 2005, at 3:27 PM, Steve Allen wrote:Finally we begin to see folks stand up and identify their systems as having abysmally failed to implement the UTC standard. http://www.acrelectronics.com/alerts/leap.htmEven more remarkably, they proudly proclaim: "The quality systems of this

Re: a system that fails spectacularly

2005-12-07 Thread Rob Seaman
. Rob Seaman National Optical Astronomy Observatory

Re: a system that fails spectacularly

2005-12-07 Thread Rob Seaman
solid state physics or the airframe designer, fluid dynamics? The Earth rotates. For some purposes, some people can ignore this. For other purposes, other people can't. Deciding the implications requires actual thought and planning. Is this really a radical notion? Rob Seaman National Optical

Re: Lighter Evenings (Experiment) Bill [HL]

2005-12-19 Thread Rob Seaman
and oranges, we're talking about apples and the rate of change of qumquats. In fact, it is remarkable that the existence of a significant acceleration (second derivative or quadratic effect) in the need for leap seconds is being asserted as a bogus justification for not issuing leap seconds at all. Rob

Re: Schreiver AFB warns about leapsec

2005-12-20 Thread Rob Seaman
On Dec 20, 2005, at 1:30 AM, Poul-Henning Kamp wrote:There is an interesting PowerPoint (sigh...) at Schriever AFB's GPS support center:https://www.schriever.af.mil/GpsSupportCenter/archive/advisory/Leap_Second_Event.pptAgreed.  Very interesting.They clearly know what the problem with leap seconds

Re: Schreiver AFB warns about leapsec

2005-12-20 Thread Rob Seaman
, but this occurs only something like 36% of the time. Would greatly appreciate knowledgeable comments from list members in Japan or Australia. This scheduling was a conscious design choice. I'm asserting it may not have been the right choice. Rob Seaman National Optical Astronomy Observatory

went pretty dang smoothly at this end

2005-12-31 Thread Rob Seaman
problem (and lack thereof) reports to me. Will comment further when these are available. Rob Seaman National Optical Astronomy Observatory

Re: Leap Second Countdown Clock

2005-12-31 Thread Rob Seaman
. Rob Seaman National Optical Astronomy Observatory

Re: Where the responsibility lies

2006-01-03 Thread Rob Seaman
off the accumulation in smaller, more frequent doses is a better choice. Rob Seaman National Optical Astronomy Observatory --- ancient.pdf Description: Adobe PDF document

Re: Longer leap second notice, was: Where the responsibility lies

2006-01-03 Thread Rob Seaman
be some interesting hay to be made by generalizing our definition of a clock to include quasi-periodic phenomena more complicated than a once-per-second delta function. Would give us some reason to explore the Fourier domain if nothing else. Rob Seaman National Optical Astronomy Observatory

Fwd: [LEAPSECS] Longer leap second notice

2006-01-04 Thread Rob Seaman
(for once). (Some might consider me a software professional as well - am not particularly annoyed if you do not.) Would be delighted to hear more about your leap second infrastructure. Rob Seaman National Optical Astronomy Observatory

Re: Longer leap second notice

2006-01-04 Thread Rob Seaman
for the changing light travel time across the Earth's orbit. I won't belabor the point (much), but it certainly is easier to build trust in the correctness of such a trigger if the cadence is rapid, rather than glacially slow. Rob Seaman National Optical Astronomy Observatory

Re: civil time = solar time

2006-01-05 Thread Rob Seaman
Suffered a disk crash and lost my response to this. Don't have the heart to recreate it in detail. You all know the sorts of things I would say, anyway. Might make an amusing parlor game to write your own replies in my - ahem - style :-) Poul-Henning Kamp wrote: neither local time nor civil

Defining our terms (was Re: [LEAPSECS] Longer leap second notice)

2006-01-06 Thread Rob Seaman
it is permitted to drift before action is taken - and what kind of action is appropriate - and who gets to make these decisions. Rob Seaman National Optical Astronomy Observatory

Re: The real problem with leap seconds

2006-01-07 Thread Rob Seaman
Hi Ed, Poul-Henning Kamp wrote: What a weird concept... Why not go the full distance and define a timescale for each particular kind of time-piece: and give each of them their own unique way of coping with leapseconds ? Ignoring the ridiculous parody - no, it's not a weird

The opportunity of leap seconds

2006-01-07 Thread Rob Seaman
the latter (small, frequent, fractional leaps) rather than the former (large, rare, colossally arbitrary jumps). Rob Seaman National Optical Astronomy Observatory

Re: The opportunity of leap seconds

2006-01-07 Thread Rob Seaman
On Jan 7, 2006, at 11:37 AM, John Cowan wrote:Whether we choose to bleed off the daily accumulating milliseconds one second or 3600 at a time, bleed them we must...and even people who loathe the very notion of leap seconds admit this. NO, I DON'T ADMIT THAT.  On the contrary, I deny it, flatly,

Re: predicting leap seconds

2006-01-08 Thread Rob Seaman
On Jan 7, 2006, at 11:01 PM, M. Warner Losh wrote: This would phase in the predictive timeline for leap second insertions, and would also give the IERS control to end the experiment if the time horizons exceeded their ability to predict with confidence. it would also be completely within the

Re: The opportunity of leap seconds

2006-01-08 Thread Rob Seaman
On Jan 8, 2006, at 4:41 AM, Poul-Henning Kamp wrote: It sounds to me like BIPM ought to make an Internet service available which will deliver UT1 to astronomers in a timely fashion ? Not sure BIPM is necessarily the appropriate agent, but otherwise agree 100%. Perhaps we should seek other

Re: The real problem with leap seconds

2006-01-08 Thread Rob Seaman
On Jan 8, 2006, at 5:38 AM, Poul-Henning Kamp wrote: As I understood it, it was mainly that TAI is a post-factum postal timescale. One is left pondering the fact that UTC is now (and would remain under any changes I've heard suggested) a time scale based on TAI. What magic makes one

interoperability

2006-01-08 Thread Rob Seaman
. Time zones (and the prime meridian?) would race more-and-more rapidly around the globe. Perhaps I've misunderstood, but this line of reasoning doesn't appear to resolve anything. Rob Seaman National Optical Astronomy Observatory

Re: interoperability

2006-01-08 Thread Rob Seaman
On Jan 8, 2006, at 4:04 PM, Tom Van Baak wrote: You cannot divide timekeeping, time dissemination, into neat stages. Again. My point is strengthened. This being the case, a requirement on one flavor of time transfers to others. We will not solve the problem of creeping complexity and

Re: interoperability

2006-01-08 Thread Rob Seaman
On Jan 8, 2006, at 6:41 PM, Tom Van Baak wrote: am not sure I like the idea that eventually my car, traffic lights, airlines, television, and my thermostat will have to be reliably tied to the IERS in order to function properly. This is a general issue with the increasingly tight coupling

Re: interoperability

2006-01-08 Thread Rob Seaman
On Jan 9, 2006, at 12:03 AM, John Cowan wrote: Each locality decides when and how to adjust both its offset from TAI and its seasonal transition function (if any), just as it does today. Not just as today, see intervening messages. What we abandon is a universal time tightly synchronized to

Re: interoperability

2006-01-09 Thread Rob Seaman
On Jan 9, 2006, at 12:06 AM, Poul-Henning Kamp wrote: You yourself defined stage one as TAI with some constant offset yourself, you can't change definition in the middle of the discussion. I was attempting to describe your position. In point of fact, I agree with Tom Van Baak: You cannot

Re: interoperability

2006-01-09 Thread Rob Seaman
On Jan 9, 2006, at 12:23 AM, John Cowan wrote: This is like the day is light and night is dark statement: there is, at any given location, one and only one sunrise per (solar) day, no matter what clocks say. Communication prospers when people's clear meaning is not subjugated to petty

Re: interoperability

2006-01-09 Thread Rob Seaman
On Jan 9, 2006, at 1:01 AM, Clive D.W. Feather wrote: We go through such discontinuities twice a year in most years. Only the uninteresting daylight saving jumps. UTC remains without discontinuities above the level of a leap second. If UTC weren't equivalent to what I call civil time, the

Re: interoperability

2006-01-09 Thread Rob Seaman
On Jan 9, 2006, at 1:22 AM, Clive D.W. Feather wrote: At some point, probably around the time that we're seeing an hourly shift every year, people are going to have to divorce second from day, or at least re-negotiate the terms of engagement. By what magic do we believe the issues involved

Re: MJD and leap seconds

2006-01-10 Thread Rob Seaman
On Jan 10, 2006, at 9:17 AM, Peter Bunclark wrote:On Tue, 10 Jan 2006, Poul-Henning Kamp wrote:In message [EMAIL PROTECTED], Peter Bunclark writes: Good grief.  MJD is used widely in astronomy, for example in variablility studies where you want a real number to represent time rather than deal with

Re: MJD and leap seconds

2006-01-10 Thread Rob Seaman
On Jan 10, 2006, at 11:06 AM, Poul-Henning Kamp wrote: Let me see if understood that right: In order to avoid computing problems and to get precise time, astronomers rely on a timescale without leapseconds, because the Earths rotation is too unstable a clock for their purposes. Just like

War of the Worlds

2006-01-11 Thread Rob Seaman
I see Steve Allen has already supplied a thorough answer. Interested individuals might also scrounge through the list archives (http:// rom.usno.navy.mil/archives/leapsecs.html) since the topic has come up before. In fact, Demetrios Matsakis speculated on solar system wide timescales even

Monsters from the id

2006-01-11 Thread Rob Seaman
What now, Dr. Moebius?                      Prepare your minds for a new scale...                    of physical scientific values, gentlemen.Mark Calabretta takes the lazy man's way out and appeals to facts: Here in a topology-free way is what the axis labels of my graph looklike during

Re: Monsters from the id

2006-01-12 Thread Rob Seaman
On Jan 12, 2006, at 12:36 AM, John Cowan wrote:No one, at least not on this list, is arguing for an alignment of theabsurd leap hour proposal (henceforth ALHP) with DST changes.I went rummaging through the ITU proposal and back as far as Torino.  Found this comment from a LEAPSECS thread on 28

Re: The real problem with leap seconds

2006-01-13 Thread Rob Seaman
I'm glad to see such active traffic on the list - particularly discussions such as this that are wrestling with fundamental concepts. On 2006-01-13, Mark Calabretta wrote: The point is that UTC is simply a representation of TAI. On Jan 13, 2006, at 4:17 AM, Michael Deckers wrote: I

Re: The real problem with leap seconds

2006-01-13 Thread Rob Seaman
On Jan 13, 2006, at 8:05 AM, Ed Davies wrote: MJD 27123.5 means 12:00:00 on day 27123 if it's not a leap second day, but what does it mean on a day with a positive leap second? 12:00:00.5? And we're back to the point in question. The precise issue is the definition of the concept of a day.

Re: Monsters from the id

2006-01-14 Thread Rob Seaman
On Jan 13, 2006, at 12:46 AM, John Cowan wrote: In the end, it will be impossible to maintain the notion that a solarday is 24h of 60m of 60s each: we wind up, IIRC, with the solar dayand lunar month both at about 47 current solar days. There's a lot of difference between what happens over a

Re: Report of Leap Second Problem with GPS Data

2006-01-14 Thread Rob Seaman
that some other data products were unaffected? So, the issue has been resolved - would likely have been resolved sooner if a leap second had occurred earlier - and is no longer directly pertinent to a discussion of future leap seconds? Well done, Geoscience Australia! Rob Seaman NOAO

Re: Problems with GLONASS Raw Receiver Data at Start of New Year

2006-01-14 Thread Rob Seaman
-round and the media circus would have moved on. Rob Seaman NOAO

Re: Report of Leap Second Problem with GPS Data

2006-01-14 Thread Rob Seaman
This goes counter to my claims so it is of no importance. and This time, there were no reports of death with the leap second, therefore they can't be too bad... :-) I invite derision with my flights of rhetoric. But this is an internet forum and a little leeway may be warranted. We all

Re: Problems with GLONASS Raw Receiver Data at Start of New Year

2006-01-14 Thread Rob Seaman
days - or alternately, to convert Universal Time into a count of seconds - that creates confusion between the two. Rob Seaman NOAO

Re: Problems with GLONASS Raw Receiver Data at Start of New Year

2006-01-15 Thread Rob Seaman
choices should be made adds a little spice to the discussion :-) UNB1 Web page is here: http://gge.unb.ca/Resources/UNB1.html. IGS Central Bureau Web page is here: http://igscb.jpl.nasa.gov/ Thanks for the pointers. Rob Seaman NOAO

Risks of change to UTC

2006-01-16 Thread Rob Seaman
that many deployed systems (of whatever nature) are naively configured. Is this likely to change overnight? Rob Seaman NOAO

Re: Internet-Draft on UTC-SLS

2006-01-19 Thread Rob Seaman
-SLS is intended to serve all needs. Rather, we've heard the opposite. Suspect I'm not alone in being suspicious of any overreaching solution proffered for all timekeeping situations - sounds like the definition of a kludge. Rob Seaman NOAO

Re: Internet-Draft on UTC-SLS

2006-01-19 Thread Rob Seaman
On Jan 19, 2006, at 10:02 AM, Rob Seaman wrote: How delightful! A discussion about the design merits of actual competing technical proposals! Apologies for failing to credit the quotes from Poul-Henning Kamp.

Re: Internet-Draft on UTC-SLS

2006-01-19 Thread Rob Seaman
be tempted to suggest that we don't even try, but rather look for separate solutions to various pragmatic classes of timekeeping needs. Glad to see the list moving in that direction. Rob Seaman NOAO

Re: Risks of change to UTC

2006-01-21 Thread Rob Seaman
to convert shipboard apparent time to local mean time. Subtraction does the rest. Rob Seaman NOAO

Re: Risks of change to UTC

2006-01-21 Thread Rob Seaman
is the Russian Global Navigation Satelllite System :-) In any event, one suspects that the Russians (or the FSU, even more so) would object to its being characterized as a GPS backup. Rob Seaman NOAO

Re: Risks of change to UTC

2006-01-21 Thread Rob Seaman
for either scientists or sailors. Whether we're also selfish is immaterial. Rob Seaman NOAO

Re: Approach to leap second discussion

2006-01-22 Thread Rob Seaman
I hope we can all continue this discussion in a more positive manner. I'm of the opinion that messages on this list (no matter how tricky :-) are always positive. Timekeeping is a fundamental issue. It would be remarkable if there weren't diverse opinions. Any negative aspects of this

Re: the tail wags the dog

2006-01-23 Thread Rob Seaman
On Jan 23, 2006, at 9:33 AM, M. Warner Losh wrote: The legal time in the US is the mean solar time at a given meridian, as determined by the secretary of commerce ...and many may have seen Mr. Gutierrez shooting the sun with his sextant out on the Mall in front of the AS Museum :-) With all

Re: the tail wags the dog

2006-01-24 Thread Rob Seaman
On Jan 24, 2006, at 12:50 AM, Peter Bunclark wrote: I don't think Rob meant the above to be a complete course on navigation! ...although as a fan of Patrick O'Brian I am qualified not only to teach navigation, but also the violin and Catalan. You should see me in a Bear costume. Good

Re: the tail wags the dog

2006-01-24 Thread Rob Seaman
On Jan 24, 2006, at 8:06 AM, Ed Davies wrote: James Maynard wrote: The problem is not that the SI second is not based on a natural phenonemon (it is), but that the periods of the various natural phenonema (rotations of the earth about its axis revolutions of the earth about the sun,

Re: the tail wags the dog

2006-01-24 Thread Rob Seaman
On Jan 24, 2006, at 7:21 AM, Poul-Henning Kamp wrote:I think the crucial insight here is that geophysics makes (comparatively) lousy clocksThe crucial insight is that the Earth is not a clock at all, but rather the thing being timed.and we should stop using rotating bodies of geophysics for 

worthy challenges

2006-01-24 Thread Rob Seaman
Ed Davies wrote:By "rubber seconds" you, presumably, mean non-SI seconds.  What do you mean by "rubber days"?  I'd guess you mean days which are divided into SI seconds but not necessarily 86 400 of them.Yes.  See for instance:

The nature of risk

2006-01-25 Thread Rob Seaman
are asserted to be a risk. Does their lack present fewer risks? Prove it. Rob Seaman NOAO

Re: The nature of risk

2006-01-25 Thread Rob Seaman
Leap seconds are asserted to be a risk. Does their lack present fewer risks? Prove it. No, you prove it. Such rhetorical devices are designed to divide and separate, No, my rhetoric really isn't designed for that purpose. And even if it were so - how does that possibly undermine the idea

Re: Comparing Time Scales

2006-02-04 Thread Rob Seaman
/4800) aren't even denumerable with the length of our week. Why then is a requirement that one minute out of 800,000 accommodate one extra (or one fewer) second seen to be such an imposition? Especially when anybody who does find it so can simply choose to use TAI instead? Eppur si muove! Rob

Re: An immodest proposal

2006-02-14 Thread Rob Seaman
On Feb 14, 2006, at 12:50 PM, Markus Kuhn wrote: You can, of course, define, publish, implement, and promote a new version (4?) of NTP that can also diseminate TAI, EOPs, leap-second tables, and other good things. I'm all for it. But why are you for it? Before investing large amounts of time

Re: An immodest proposal

2006-02-14 Thread Rob Seaman
On Feb 14, 2006, at 2:28 PM, M. Warner Losh wrote:UTC time stamps in NTP are ambiguous.  TAI ones are not.Requirements should be kept separate from implementation.  Whatever the underlying timescale, certain external global requirements apply.  Whether NTP or some other implementation properly

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Rob Seaman
On Feb 16, 2006, at 2:06 PM, Markus Kuhn wrote: While there is a 24:00:00, there is certainly *no* 24:00:00.0001. That would be 00:00:00.0001 instead. Says who? Didn't we just burn a lot of calories discussing whether UTC was a real number or a continuous function? Time does

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Rob Seaman
On Feb 16, 2006, at 4:46 PM, Warner Losh wrote:UTC rules state that the time sequence should be23:59:59.7523:59:60.023:59:60.2523:59:60.5023:59:60.7500:00:00.:00:00.25Well, no.  ITU-R-TF.460-4 says nothing whatsoever about the representation of time using sexigesimal notation: "2.2 A

Re: 24:00 versus 00:00

2006-02-17 Thread Rob Seaman
window around midnight - say, 23:59-00:01, or 2 out of 1440 minutes per day. It should be even easier for NTP and other UTC transport mechanisms to avoid 2 minutes out of 365+ days. This isn't the solution to every challenge facing civil time - but it sure simplifies the search space. Rob Seaman

Re: 1884 IMC online

2006-02-20 Thread Rob Seaman
On Feb 19, 2006, at 1:35 PM, Steve Allen wrote:A few years ago Joseph S. Myers of Cambridge University went through the trouble of scanning a copy of the proceedings of the 1884 International Meridian Conference, and I put the TIFFs online http://www.ucolick.org/~sla/leapsecs/scans-meridian.htmlI

Re: 24:00 versus 00:00

2006-02-27 Thread Rob Seaman
On Feb 17, 2006, at 12:30 PM, Markus Kuhn wrote: Clive D.W. Feather wrote on 2006-02-17 05:58 UTC: However, London Underground does print 24:00 on a ticket issued at midnight, and in fact continues up to 27:30 (such tickets count as being issued on the previous day for validity purposes, and

Re: ideas for new UTC rules

2006-04-14 Thread Rob Seaman
On Apr 13, 2006, at 10:41 PM, Steve Allen wrote:Today is one of the four days in the year when Newcomb's_expression_ for the equation of time has a value of zeroand it was Samuel Beckett's hundredth birthday.  Leap second as Godot: ESTRAGON: And if he doesn't come?

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