[LEAPSECS] LEAPSECS Digest, Vol 45, Issue 4

Nero Imhard nimh at pipe.nl
Fri Sep 3 09:47:43 EDT 2010

Tony Finch wrote:

> The proposed redefinition of UTC is perhaps more like the redefinition of

> the yard from an independent standard of length to a multiple of the

> metre, or...

Not at all. The redefinition of UTC is not simply switching to another,
presumably more stable, static reference and sticking in a conversion
factor, as was the case with the yard, metre and second.

Historically there have been various mechanisms (rubber seconds, leap
seconds...) to synchronize civil time with solar time. These mechanisms
clearly indicate that closely following solar time is an intentional and
defining property, fully incorporated in UTC.

What the ITU proposes is not refining the synchronisation mechanism, which
would make UTC "better" (in the same way we've come up with better
definitions for yard etc.), but instead abandoning the relationship
altogether, which is much more fundamental, and would "break" UTC.


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