Warner Losh <i...@bsdimp.com> wrote: > On Jan 18, 2014, at 1:52 PM, Stephen Scott wrote:
> > The basis of my understanding is that UTC is a timescale that: > > - progresses at a rate of the second (SI) and has done so since > > 1972-01-01. > > - is expressed as a count in the form of date, hours, minutes and > > seconds; > > - is continuous other than the discontinuities resulting from leap > > second corrections; > > To pick a pedantic nit: It is continuous. No "other than". UTC is a > continuous time scale. It has a non-uniform radix that is expressed at > the leap seconds when its rules for labeling seconds changes slightly to > label the leap second 23:59:60. The timescale has a discontinuity when > there's a phase jump. UTC does not have phase jumps, even if it chooses > a non-traditional time to label some of its seconds once every year and > a half or two. I think it is reasonable to say that UTC's labelling of seconds is discontinuous. For timescales that use simple ancient sexagesimal notation you can write down some straightforward formulae mapping between a count of seconds and a broken down time. If you try to do the same for UTC you have to write down something that is piecewise linear with exceptions. It isn't a continuous map like other timescales. Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ Forties, Cromarty: East, veering southeast, 4 or 5, occasionally 6 at first. Rough, becoming slight or moderate. Showers, rain at first. Moderate or good, occasionally poor at first. _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
