[time-nuts] GPSDO for my rubber duckie
albertson.chris at gmail.com
Tue Aug 2 23:17:44 UTC 2011
On Tue, Aug 2, 2011 at 3:49 PM, Chris Stake <stake at btinternet.com> wrote:
> I don't get it.
> Does that mean that leap days are OK but leap seconds are unacceptable?
It's even less logical than that. With "rubber seconds" tied to the
Earth's rotation. You ultra stable cesium clock is no longer running
at a fixed frequency. If the length of the second changs with the
Earth's rate then the frequency of the cesium clock can be effected by
earth quakes in Japan, tides and what not.
I guess it's a valid decision to either
(1) fix the length of the second and let the number of seconds per day
be "whatever the Earth decides" so some days have an extra second and
most don't. or,
(2) define the day as 60 x 60 x 24 seconds long. And let the length of
a second be continuously variable or
(3) fix the length of the second AND define the day as 60 x 60 x 24
seconds long and just accept that after some centuries the sun will
raise in mid morning.
Using #2 makes the job of maintaining a frequency standard more interesting.
That said of all the systems I like the Mayan one best. They defined
the year as 360 days. Then after 360 days they stopped counting and
had a party while they waited for the priest to watch the sun and
declare the start of a new year. They got a week off.
Redondo Beach, California
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