[LEAPSECS] comments on UTC

[GERRY ASHTON]

> On June 6, 2018 at 12:57 PM Rob Seaman <seaman at lpl.arizona.edu> wrote:
> 
> 
> Usual range of opinions. These guys think they've solved the problem for
> all time:
> 
>     https://news.wisc.edu/thank-the-moon-for-earths-lengthening-day/
> 
> As you say, not much pertinent to leap seconds.
> 
> Rob
> --
> 
> I'm not sure any solution created by a computer programmer is "real
> world" :-)
> --
> 
The work does not seem pertinent to near-term calculation of leap seconds. But it might be pertinent to establishing policy about leap seconds. One of the arguments that comes up in policy discussions is that in several thousand years, the method of adapting to changing LOD by leap seconds breaks down because more than one leap second will be required per day. But such calculations fall outside the range of validity of models typically used for ephemeris calculations. Those performing such calculations would have to select longer-term models. The longer-term models might be invalidated, at least at the extremes of their claimed range of validity. If a researcher's chosen model were shot down, over any part of its range, the researcher's conclusions would be cast into doubt, even if the researcher avoided the extremes of the model range.

Gerard Ashton