[LEAPSECS] Far past and far future

Rob Seaman seaman at noao.edu
Sun May 29 16:46:03 EDT 2011

Um, I said "if this unfortunate occurrence happened in the current day". It is fairly remarkable that the current UTC standard would scale to handle this admittedly unlikely scenario.

On the other hand, the ITU's wise and beneficent guidance will fail to scale to the epoch when LOD is 86401 SI-seconds, let alone 172800 SI-seconds.

The issue is not leap seconds, it is the definition of universal time.

On May 29, 2011, at 1:27 PM, Clive D.W. Feather wrote:

> Rob Seaman said:

>> So, if the moment of inertia increases by 0.2 parts per million, the angular velocity must decrease by the same amount to keep the angular momentum constant. If this unfortunate occurrence happened in the current day, length of day would thus increase by 0.017 SI-seconds. This would require a leap second six times per year to accommodate.


>> ...and this is *still* within the scope of the current definition of UTC to accommodate - plus a comfy factor of two for monthly Shannon-Nyquist sampling.


> Um, this is at a time when LOD is about 172800 seconds. That's a leap

> second *every second*.

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