[LEAPSECS] Caveat emptor!

[Rob Seaman]

Tony Finch wrote:


> I don't see how. GMT was just a realization of UT2 (ish).


No.  GMT was (and is) a widely used term by the general public.  By comparison, UT2 is a linguistic (and technical) footnote.  Read Sobel's "Longitude".  Greenwich Mean Time is a major historical story.  Stories need words.


> What this has to do with the definitions of technical terms I have no idea.


This entire 10+ year conversation has been about civil timekeeping.  Some want to interpret it as some merely quaintly technical issue.  The corresponding technical issues are hellaciously more complex than we juggle here.  Civil timekeeping is about all those hundreds of millions or billions of clocks worldwide, not (primarily) about astronomical observatories or precision timekeeping labs.


>> How does one refer to TCFKAUT ("The Concept Formerly Known As Universal Time") after "UTC" is redefined and "GMT" has fallen into disuse?

> 

> "Universal Time", duh.


No.  The words "Universal Time" will be ambiguous.  Under any given circumstances listeners will ask whether their usage in a document refers to the redefined UTC, or to the original UTC (documents are forever), or to some other variation such as GMT or UT1 or UT2, or just to the general concept of a timescale stationary with respect to the synodic day.  Will a speaker making a presentation be referring to the redefined civil timescale or the old-style civil timescale or the quantity that is juggled so adroitly in the Explanatory Supplement to the Astronomical Almanac?

Since UTC has remained an "approximation or measure" of Greenwich Mean Time, we haven't had to face these ambiguities.  Some of those here will poo-poo ( or "duh") the question.  It is, however, a real question.  If you don't think so, you might consider not participating in this particular conversation.  Surely saying "duh" is the definition of introducing noise into an online forum?

So, to say it again - should the ITU succeed in introducing a new and conflicting definition for UTC, what happens to Universal Time?

Rob