[ntp:questions] Leap second to be introduced in June

David Woolley david at ex.djwhome.demon.invalid
Mon Jan 26 18:03:51 UTC 2015

On 26/01/15 17:11, William Unruh wrote:
>> physical principle ( the frequency of oscillation of a cesium atom in a
>> >certain transition) and the rotation of the earth. It used to be defined
>                           ^not
>> >

It's a quantum spin flip.  There is no physical oscillation. Not that 
that really changes anything about UTC or TAI.

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