## PSN-L Email List Message

Subject: Re: clock pendulums
From: Dave Nelson dave.nelson@...............
Date: Fri, 25 Mar 2011 06:51:56 +1100

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I would have to disagree with that Chris

P waves are a longitudinal wave ... its a compressional/dilational wave in
the direction of travel

From wikipedial and other sources agree .....

.. The name P-wave stands either for primary wave, as it has the highest
velocity and is therefore the first to be recorded, or pressure wave,[1] as
it is formed from alternating compressions and rarefactions.

In isotropic and homogeneous solids, the polarization of P-waves is always
longitudinal. This means that the particles in the body have vibrations
along or parallel to the direction of travel of the wave energy.

cheers
Dave

>Hi Bryan,
>
>     P waves give a vertical displacement at right angles to the direction
> of  propagation. Distant quakes are likely to have a
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>     Chris Chapman
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>    Am I correct in assuming that your clocks use a vertical pendulum with
> a period between 1 and 2 seconds?
>Bryan Mumford

I would have to disagree with that Chris
P waves are a longitudinal wave ... its a compressional/dilational wave
in the direction of travel
From wikipedial and other sources agree .....
. The name P-wave stands either for primary wave, as
it has the highest velocity and is therefore the first to be recorded, or
pressure wave,[1] as it is
formed from alternating compressions
and rarefactions.
In isotropic and homogeneous solids,
the polarization of P-waves is always
longitudinal. This means that the
particles in the body have vibrations along or parallel to the direction
of travel of the wave energy.
cheers
Dave

Hi
Bryan,

P waves give a vertical displacement at
right angles to the direction of  propagation. Distant quakes are
likely to have a

Chris
Chapman

Am I correct in
assuming that your clocks use a vertical pendulum with a period between 1
and 2 seconds?
Bryan
Mumford

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