Re: [LEAPSECS] the big artillery
So days may come and go, but UTC with or without leap seconds meets its definition just fine - for those who just think of it as a universally agreed-upon time reference that's coordinated by timing labs. It is not amibuguous if this universal reference coincides with UT1 to .9 seconds until 2020 and then less closely thereafter - that's just the way it would work out. On 11/1/14, Dennis Ferguson wrote: > > On 30 Oct, 2014, at 12:12 , Richard Clark wrote: >> Well, for historical and archival purposes Julian date nearly always >> means >> traditional days, as in solar days. But for astronomical uses a fixed >> unit, the apocryphal atomic day is implied. This means needing to know >> delta T if you need to relate it back to a civil date or time. >> >> The term 'day' has an awful lot of linguistic baggage that clearly >> implies that the solar day is meant. But now the use of 'day' can be >> at the speaker's and listener's risk. >> >> The minute, hour, day, year... these are not SI units. We need to >> start considering it sloppy to use them as if they are. >> >> Do we mean 'atomic day'? If so we need to: >> 1. say so, and >> 2. make it official by defining, rather than just implying one. >> >> Perhaps hectosecond would be better. At least it doesn't invite >> confusion. >> >> Yeah, and now to convince anyone to do this. > > I agree with that. > > While it is true, though, that the minute/hour/day are not SI units > they are accepted by the CIPM for use with the SI with dimensions > of time using their traditional (dating back to Ptolemy?) defined > relationships to each other when the second used is the SI version. > Table 6 here > > http://physics.nist.gov/Pubs/SP330/sp330.pdf > > lists the CIPM definition, to which TT as a JD seems to conform. > Solar days/hours/minutes/seconds don't conform, but since their > dimensions are now rotational angle rather than time this is a > use of the units which is off label with respect to SI even if > it is a traditional and original use of units with those names. > > I guess the point is that while "day", like many traditional > units, is ambiguous and in need of a qualifier to know exactly > which kind is being referred to, a definition of "day" as a > standard time unit which is 86400 SI seconds long already exists > and is in use. This requires no new invention. > > Dennis Ferguson > ___ > LEAPSECS mailing list > LEAPSECS@leapsecond.com > https://pairlist6.pair.net/mailman/listinfo/leapsecs > ___ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] IAU UTC report
This is very strange. It is evident that the IAU WG is not the IAU, but this is not admitted by the responder above. Instead he repeats his position on renaming UTC and suggests - but does not say - that the WG resolution was transmitted to the ITU effectively in the name of the IAU. Perhaps yes, perhaps not. Also, the Torino concensus is again referred to. Yet the very references quoted - for both the IAU WG and Torino - indicate there was no concensus. And this has been pointed out before, at least for Torino. Also the IAU one indicates little interest outside the WG - not what you would expect if astronomy is about to be thrown to the wolves. All these persistent distortions convince me that at least the one supporter of a name change I am quoting is really advocating that as a poison-pill. I've googled the positions of several of the people on the IAU WG, and it seems to confirm the thesis that the IAU WG position was the result of a vote, not a compromise. Either way, the co-chair Dr. Arias, as befitting her responsibilities, went ahead and reported the outcome of what some call a vote even though it went against her beliefs. She seems to be very honest, as would be her co-chair Dr. McCarthy. I've found that in several astronomical bodies have come out in favor of abolishing leap seconds. According to Matsakis, http://www.gps.gov/cgsic/meetings/2014/, the American, Japanese, and European Space agencies (NASA, JAXA, and ESA) support ending leap seconds. These are real-time users that would have the most to lose if leap seconds were truly useful for space astronomy. He doesn't mention GLONASS directly, but there is a viewgraph responding to the Russian pro-leapsecond position. I don't think it would be right to dismiss the American, Russian, and Japanese agencies as being controlled by their governments - according to the reference, the American decision-making process was public and consulted NASA. I found a reference to that in the leapseconds archives too. Also, the ESA is international. So the astronomical institutional vote so far is 75% in favor of abolishing leap seconds, with one abstention (IAU).That certainly does not support the idea that abolishing leap seconds is sacrificing astronomy in favor of navigation. On 11/7/14, Rob Seaman wrote: > On Nov 6, 2014, at 10:19 PM, Alex Currant via LEAPSECS > wrote: > >> I am sorry but my statement was correct: the IAU has not taken a stand. > > That wasn't your complete statement. You went on to speculate "if it were > so simple then the disagreements that were expressed in the IAU > deliberations would not have been sufficient to prevent a resolution." > Rather, the working group deliberations produced a unified report signed by > all members including Dr. Arias: > > http://hpiers.obspm.fr/eop-pc/earthor/utc/report_WG_UTC_2014.pdf > > The terms of reference for the working group included: > > “Responding to the proposal of recommendation to establish a continuous > reference timescale under the International Telecommunication Union, this > working group will discuss about the redefinition of UTC from the > perspectives of IAU” > > To the extent that the IAU has a perspective on this issue, the working > group report expresses it. It is not accurate to say that the IAU has not > taken a stand, rather the working group was split between two strong > positions about continuing leap seconds, but the entire working group agreed > that 'in the event of the deletion of future leap seconds the name of the > scale should no longer reference the astronomical time scale “Universal > Time”'. > >> My statement was correct because an IAU Working Group is not the IAU, and >> that IAU leadership has been explicitly clear about this point. > > Speculation about the intentions of the IAU is unwarranted. One cannot > simultaneously argue that the IAU has not taken a stand while saying that > the IAU leadership's intentions are explicitly clear. > >> Similarly, it appears you have distorted the Torino meeting by suggesting >> a consensus existed. The summary of that meeting, as referenced on Steve >> Allan's web pages for example, specifically states that there was no >> concensus, yet you claim one existed. > > As with the IAU UTC working group, the consensus of the Torino meeting was > split on the question of whether the status quo should be maintained. > However, as with the report of the IAU working group, the closing summary > report of the Torino meeting: > > http://www.ucolick.org/~sla/leapsecs/torino/closure.pdf > > expresses (verbatim) conclusions including the "preferred characteristics of > a potential alternative" as below: > > Objectives : > > • To address the future of the Leap Second and related issues. > • To draft a recommendation on the next steps on this issue to WP7A of > the > ITU-R. > > Conclusions: > > • There was no overwhelming consensus on a whether the status quo > should be >
Re: [LEAPSECS] IAU UTC report
On 11/9/14, Rob Seaman wrote: > It's good to see new names appearing on the leapsecs list. Perhaps new > folks might introduce themselves and describe the interest of their > institutions in the proposed redefinition of UTC? > > I have some science background, and am into conflict resolution and the role of cognitive dissonance and misinformation. I was warned about this list and that emails could turn negative, but so far I have seen nothing of the sort. Thank you for your patience. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] The definition of a day
>From the point of view of conflict resolution, there is a difference between disagreeing with someone about what is important or what is valid, and not acknowledging that his argument even exists. Several recent emails by those who want to end leap seconds are saying that sometimes the other side just ignores their arguments as if they had never been made, and that various resolutions are greatly misquoted. There is a presentation on the USNO web pages that says it has referenced every argument made by those who want to keep leap seconds. Do people who want to keep leap seconds claim that this presentation and others like it have not even acknowledged the very existence of their concerns? This is different from saying that their opinions are disagreed with, considered not important, or even ridiculed. On 1/30/15, Ian Batten via LEAPSECS wrote: > >> On 30 Jan 2015, at 10:34, Hal Murray wrote: >> >> >>> So, let us suppose the year 2600 is when the drift reaches the annoying >>> point, and let us suppose the EU is still in existence. By then the sun >>> will >>> reach its highest point at about 12:45 UTC. So at this point the EU >>> announces (a few years ahead) that the normal autumn shift back of the >>> clocks will not happen. ... >> >>> Dealing with local time changes as you cross borders is something people >>> are >>> used to, as is the fact that the amount of change varies both within the >>> year and from year to year. So there's nothing new for people to get >>> used >>> to. >> >> It's not as simple as just skip an hour shift. >> >> I'm in the US. We are used to dealing with hour shifts in the >> spring/fall. >> But the system has had years to get used to that. If you skip one, then >> all >> sorts of things need to get adjusted. I'm thinking of things like schools >> >> starting in daylight so there are fewer traffic accidents. It doesn't >> matter >> if they start at 8AM or 9AM or 7AM, but if they have been starting at 8AM >> and >> you adjust the clocks by an hour you need to adjust the starting time by >> an >> hour to get back to where you want to be. > > Firstly, the research says if you only have enough daylight such that you > have > to choose, in fact starting schools in the dark produces fewer traffic > accidents, > because going home in the dark (when drivers are tired) is a higher risk > than > going to school in the dark (when they are less tired). The experiment is > the > UK 1968 to 1971, when we abandoned the shift and stayed on GMT+1 all year > around. > I'm old enough to remember it, just, Clive being a few years older than me > is > probably a better witness. > > Secondly, the UK have turned daylight savings on and off on multiple > occasions in > varying ways: the transition to and from the aforementioned British > Standard > Time, the transition in 1940 and 1945 into and out of GMT+1/GMT+2 that > persisted > through the second world war, the temporary re-introduction of double summer > time in 1947. > > We dealt with it. The problem with all the "these problems are > insurmountable" > arguments is that they manifestly are surmountable. We've done it. Several > times. > Often with bombs falling at the same time. > > ian > > > > ___ > LEAPSECS mailing list > LEAPSECS@leapsecond.com > https://pairlist6.pair.net/mailman/listinfo/leapsecs > ___ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] The definition of a day
Cultural aspects have been been used as debating points in these discussions. Culture is being used to justify the abuse of women, so it is important to understand what it means and what it does not mean. I have found two things that culture means with regards to the leap second. First, anthropologist Kevin Birth suggests that one cultural aspect is nationalism, which is not entirely English. He says a British minister warned that without leap seconds time will move to America, and also that the French never did accept GMT. Dr. Matsakis's viewgraphs say that UTC is referred to as GMT in the British media, and that nationalistic reasoning was part of the British public debate. In an email last year, Dr. Birth suggests that some elements of the third world might be favorably disposed towards the ITU resolution because they see it as anti-colonialist. Some of the other emails make it seem like another cultural aspect would arise if people's daily lives were altered with respect to the sun. Here other people say there are no more cultural aspects to this than happens now when countries change time zones. That is either because countries can adjust by switching their time zone definitions every many-hundred (or thousand) years, or because people will get so used to the clock readings being different as they go about their daily lives that they won't want to adjust.People have accused those against leap seconds of deliberately ignoring predictions that the divergence will be less rapid than previously thought. Is there anything else to the cultural aspects besides these two elements? On 1/30/15, Rob Seaman wrote: > On Jan 30, 2015, at 8:41 AM, Warner Losh wrote: > >> Rob loves to quote the archives as if they irrefutably prove his point. > > My point is that a coherent approach to systems engineering would be the > most efficient and robust way to resolve the issue. Is this controversial? > And rather, I choose not to ignore the fact that this conversation has been > going on for many years and that we have already covered many topics in > great detail. The list archives are a great source of information and > analysis from diverse people, which is why we linked to them from > http://futureofutc.org > >> The biggest thing that’s ignored in them is that time zone can and do >> change all the time. > > They do not accelerate secularly. And the underlying Universal Time can be > recovered to tie the whole carousel of time zones together. > > Rob > > ___ > LEAPSECS mailing list > LEAPSECS@leapsecond.com > https://pairlist6.pair.net/mailman/listinfo/leapsecs > ___ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs
