Re: ideas for new UTC rules

[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 zero. ...and it was Samuel Beckett's hundredth birthday.  Leap second as Godot: ESTRAGON: And if he doesn't come? VLADIMIR: We'll come back tomorrow. ESTRAGON: And then the day after tomorrow. VLADIMIR: Possibly. ESTRAGON: And so on. VLADIMIR: The point is— ESTRAGON: Until he comes. VLADIMIR: You're merciless. ESTRAGON: We came here yesterday. VLADIMIR: Ah no, there you're mistaken. I suspect that this is almost certain to offend everyone. Ok, I'll bite - you scurrilous traitor! Yesterday was also Maundy Thursday - the day Judas betrayed (or did he?) Jesus. Today, of course, is the anniversary of Lincoln's assassination. I would not be surprised to learn that the Time Lords are already contemplating a scheme akin to this one. One suspects the Time Lords have never seriously considered any option that would preserve leap seconds in any form, to any tolerance, utilizing any scheduling algorithm - no way no how. ======Educate, educate, educate. ...but can you explain your scheme in under 23 seconds? The ITU-R should openly publish the UTC specification. Boy!  On this Easter weekend one has to believe that this would require a miracle second only to the resurrection. The reality is that the ITU-R "specification" is just a minor footnote pertaining to obsolete technologies of time signal transport.  One presumes nothing would stop the IERS from publishing any scheduling algorithm such as you describe. The IERS should enter into dialog with the International Virtual Observatory Association (IVOA) and the Internet Engineering Task Force (IETF) to determine an adequately robust scheme for guaranteeing the distribution and availability of the XML documents which give the schedule of upcoming leap seconds. This was indeed one of the notional use cases for VOEvent (http://www.ivoa.net/Documents/latest/VOEvent.html). The specification might benefit from dedicated IETF blessed support for leap second "aware" semantics, but it would be trivial even using the current standard to represent such a schedule. The emerging VOEvent transport protocol(s) could certainly propagate leap seconds as easily as reports of Supernovae, Gamma Ray Bursts and Earth-killer asteroids. To hear the detractors talk, a leap second is made to seem as dire an event as these cosmic catastrophes. As the five year prediction scheme goes into effect this will probably mean that there will be times when UT1 - UTC exceeds 0.9 seconds, but not by very much. Cannot simultaneously constrain look-ahead and DUT1 tolerance. Suggest that rather than pick any fixed window, it is sufficient to define a mechanism and format for reporting the schedule - whatever it may be at any given time.  After all - what if the state of the art improves enough to permit accurate ten year predictions? Simply allow the IERS to announce any number of leap seconds in advance extending over any time horizon - and yes - occurring at the end of any month.  If predictability is the goal, relaxing unnecessary constraints is the solution. Actually - one presumes the IERS currently has the authority to do both of these things.  Have never heard anyone suggest that the next two leap seconds might not be announced simultaneously. And the ITU-R has already signed off on the monthly scheduling of leap seconds - this is the law of the land. What precisely is stopping us from implementing some variation of Steve's scheduling algorithm right now, today, this minute? All in favor, say aye! I am still not convinced that there is any need for change.  I would like to see further examples of why the status quo is not tolerable. I think even this gives the current "process" too much credit. There has not been a single cogent example of any negative consequence of leap seconds described in a convincing and well characterized fashion.  Moaning and moping is not the same thing as making a coherent argument. Surely someone could draft a two page white paper describing to some (any) level whatsoever of technical, scientific, economic or sociological detail exactly what dreadful things happen to some particular system in the presence of a leap second?  And more to the point, to provide evidence why we should believe the cure won't be worse than the disease. Rob Seaman National Optical Astronomy Observatory