Re: More Damn "Moon's synchronism"

[Jim Green <JMGreen@sisna.com>]

Brian, it still is not clear to me that it is clear to all the list that=
 when
David Bowman talks about "tides" he _usually_ means plastic or even elastic
deformation of near solids (as in crustal tides.)  While many of the rest
of us
think of water tides as in the Earth's oceans.  And sometimes _I_ miss his
meaning.  And it would appear that he missed David Dockstader's meaning in=
 his
question about fictitious oceanic tides on the Moon. Or maybe _I_ missed=
 this
meaning. (:-)

The problem here is that not all of the list understand this AND, further, =
 he
doesn't always mean solid deformation (sometimes he means water).=A0 We end=
 up
talking past each other.   Further he uses language like "fluid" for this
deformation, which of course may be "correct"  (if he means plastic), but=
 not
always helpful to understanding.=20

As far as a datum is concerned, NOAA has defined a datum.=A0 The normal tide=
 for
each costal location with reference to that datum is given on their www site
and elsewhere.  You can see a semblance of this datum in one of the
graphics on
my tides web page.  In fact if you really want to get into it, NOAA has on
their web site the actual tidal readings (many at 10min intervals) for=
 dozens
of costal and island locations.

I intend (after the garden is planted and after I buy a new printer) to plot
this data and as a second graph the local gravitational gradient as a=
 function
of time, This to show that the force and the tide do NOT have any
correspondence.
=20
Thank you for your comments

Jim Green
JMGreen@sisna.com



Brian wrote --

> It seems to me that nobody need apologize if there is ongoing
> heat and perhaps light on the tidal topic. It signifies there is=20
> room for discussion still.
>
> In this matter, it seems like I can help in a very minor way.
> It is in the area of visualizing the water tide.
>
>
>
>
> > At 02:20 PM 3/31/98 -0500, David Bowman wrote:
> >
> > > Jim Green ... refers to the actual oscillations of the height of the
> > > water level on the shoreline of some sea coast=20
> > > ... This is *not* what I have been talking about.=20
>
> At 20:50 3/31/98 -0700, Jim Green wrote:
> > And I thought they were talking about the Earth's oceans and fictitious=
 Moon
> > oceans.=20
> ...
> > Perhaps in the future we all could specify just which tides we are talking
> > about.=20
> > ...
> > Jim Green
> > JMGreen@sisna.com
>
> Note that David cautions against coastal tide ranges, and Jim offers a
> remedy against refering to the oceanic tide as though it had a unitary
> range and frequency - when he knows it does not - near coasts.
>
> It would be far better if we chose as a datum the mid-Atlantic or
> preferably the mid-Pacific. The tidal range there would be much more
> tractable to analytical approaches it seems to me....
>
> Whatcott=A0=A0 Altus
> =20