On Tue, Jul 03, 2012 at 11:33:22PM +0100, Tony Finch wrote:
Keith Medcalf <kmedcalf@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