[time-nuts] The Pendulum Paradigm by Martin Beech, 2014

Jim Lux jimlux at earthlink.net
Wed Oct 28 22:48:50 EDT 2015

On 10/28/15 7:23 AM, Peter Reilley wrote:
> I have been pondering pendulum clocks.   I was wondering what the ADEV of a
> pendulum would show.   I assume that you could see the errors in the
> gear train.
> You should see the period of each gear.   You should see the spring wind
> down
> and being rewound.
> Further, would you be able to see the phase of the moon and the tides? This
> is using the pendulum as a gravimeter.   Would it be sensitive enough
> for that?

yes.. it's in the sub-ppm range, as I recall.

Period goes as sqrt(L/g)

from wikipedia
lunar tidal acceleration at the Earth's surface along the Moon-Earth 
axis is about 1.1 × 10−7 g, while the solar tidal acceleration at the 
Earth's surface along the Sun-Earth axis is about 0.52 × 10−7 g

So sqrt(1/(1+1E-7))... about 0.05 ppm

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