[ntp:questions] Google and leap seconds

unruh unruh at wormhole.physics.ubc.ca
Wed Sep 21 22:21:40 UTC 2011


On 2011-09-21, David Woolley <david at ex.djwhome.demon.invalid> wrote:
> unruh wrote:
>> On 2011-09-21, David Woolley <david at ex.djwhome.demon.invalid> wrote:
>>> Richard B. Gilbert wrote:
>>>
>>>> It's unfortunate that the earth DOES NOT rotate exactly 360 degrees in 
>>>> exactly 24.000000000000 hours. This bit of poor design causes all sorts 
>>> It's nothing like it.  It out by approximately 1 degree a day!
>> 
>> well, not if you define the rotation with respect to the "mean sun"
>> rather than the stars. Then it is only out by a few PPB.
>> 
>
> It makes a big difference for GPS, though.  I believe their orbital 
> period is half a sidereal day, not 12 hours or even 43200 TAI seconds.

The orbit is far faster than that. You mean the period of the orbit (not
in the orbit) as seen from earth. 

>> 




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