On Tue, Jul 03, 2012 at 11:33:22PM +0100, Tony Finch wrote: > Keith Medcalf <kmedc...@dessus.com> wrote: > > > > You are assuming facts not in evidence. The rotation is merely > > irregular within the capabilities of our scheme of measurement, > > calculation, and observation. > > There is LOTS of evidence that the earth's rotation is irregular. VLBI, > laser ranging of the moon, etc. This was known long before the atomic > clock was invented, and it is why the definition of the second was changed > from one based on earth rotation to one based on Newcomb's ephemerides, > before the change to an atomic second.
This. Shoot, seismic activity has a measurable effect. The best we can do is approximate it and align the timescales as needed. There's no lack of understanding here, just a changing planet. Now, changing your kernel's leap second handler and not testing it, well, you can't blame that one on the ITU or the aforementioned planet. --msa