[LEAPSECS] 1.26 microseconds
seaman at noao.edu
Mon Jun 13 17:43:49 EDT 2011
On Jun 13, 2011, at 2:18 PM, Poul-Henning Kamp wrote:
> In message <96366060-430F-451B-81CC-D63082CD971F at noao.edu>, Rob Seaman writes:
>> So "day" is a word referring to Earth Rotation?
> As a first order approximation, the same way a year is a first order
> approximation to earth orbital position.
Does "first order approximation" mean stationary over long periods of time?
Note, of course, that no such language is in the ITU draft.
> PS: I read an interesting note recently about how the fact that
> years have varying lengths have become an issue for determining the
> "official" half-life of long lived radioactive isotopes: Many
> geological methods just counted years, but hadn't considered how
> long those years were.
Reference? Length-of-day varies in the rich and wonderful ways we've discussed, lo these many years. If variation of length-of-year is a significant issue it has not been stated previously in this context.
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