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Author Topic: Timing the spin of the Earth  (Read 1923 times)

Offline Ben Aldhouse

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Timing the spin of the Earth
« on: 17/09/2007 13:14:42 »
Is it true that days are measurably longer due to hydro-electricity? I can imagine it might be since I believe clocks are so incredibly accurate these days that very very small time spans can be measured. However, how is the stop watch started and stopped, as it were?


 

Offline syhprum

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Timing the spin of the Earth
« Reply #1 on: 17/09/2007 14:22:34 »
There are far larger influences on the Earths rotational moment of inertia than Hydro plants the largest is the movement of air masses between the equator and the poles and the coupling between the various internal layers of the Earth.
I believe the rotational period is timed by watching the transit of a remote celestial object across the cross hairs of a special telescope but that system may have been superceded now.
 

Offline Ben Aldhouse

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Timing the spin of the Earth
« Reply #2 on: 18/09/2007 20:08:20 »
Perhaps what it was was that someone had worked out that it was possible to measure the change in the length of day due to hydroelectricity using modern clocks since clocks were accurate enough to measure that specific miniscule change.

So, are the days getting longer or shorter due to the movement of air masses and the coupling of the various internal layers of the Earth?
 

Offline syhprum

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Timing the spin of the Earth
« Reply #3 on: 18/09/2007 20:25:31 »
In the very long term (hundreds of millions of years)the rotation is slowing down but from year to year it go's up and down
 

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Timing the spin of the Earth
« Reply #3 on: 18/09/2007 20:25:31 »

 

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