On Thu 2012/01/19 18:37:25 PDT, Warner Losh wrote in a message to: Leap Second Discussion List <[email protected]>
>It is "discontinuous" for some definition of "discontinuous." If UTC is discontinuous in any sense then so must the Gregorian calendar be, with a "discontinuity" 86400 times greater on Feb/29. Noone seems at all concerned about that "discontinuity". >While strictly speaking time is an ordered, monotonically >increasing full ordered set (which would make it continuous), >it is none-the-less irregular as it has a non-uniform radix. The problem is the unpredictability of the radix, not its non-uniformity or even its time-variability which the calendar already has to a greater extent. >People that speak of it being "discontinuous" do so because >that's easier to say and explain than non-uniform radix, even >if it is pedantically incorrect. Proponents of dropping leap seconds regularly describe UTC as "discontinuous" as though it were a fundamental flaw. Just read the ITU press releases, with "discontinuous UTC" duly echoed by the press for public consumption. What's so hard about saying "the long-term unpredictability of leap seconds creates problems". >When arithmetically mapped using 86400s days, it becomes >discontinuous at the leap second. "When arithmetically mapped using 365d years, it becomes discontinuous on Feb/29" sounds less convincing. Here is my point. A "discontinuous" time-scale is a timescale that is broken beyond repair. On the other hand, a timescale with some element of unpredictability is something we have a fighting chance of doing something about, whether by improving the predictability or relaxing the tolerance or both. I think we agree that removing some of the unpredictability, at least in the medium term, is the way to achieve consensus. Mark Calabretta _______________________________________________ LEAPSECS mailing list [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
