[LEAPSECS] Nit-pick: SI second

Mark Calabretta mcalabre at atnf.csiro.au
Thu Feb 10 18:01:37 EST 2011

On Thu 2011/02/10 07:18:53 -0800, "Tom Van Baak" wrote
in a message to: "Leap Second Discussion List" <leapsecs at leapsecond.com>

>Yes, the radius of the earth is slightly dependent on latitude,

>perhaps that's what you're thinking about. But a clock at sea

>level at lat 0 will run the same as and a clock at sea level at

>lat 45 or lat 90 because that's what MSL is - the equipotential

>surface of the geoid.

A clock at the equator has a tangential velocity of 500m/s
whereas for one at the pole it is 0m/s. The difference,
amounts to about 100ns/day as per your later calculations.
This is the Sagnac effect of Special Relativity.

Mark Calabretta

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