> [Dholeman]: In the fascinating book <u>Pushing Gravity</u> Martin Kokas discussions ocean tidal loading as a possible mechanism for inducing earthquakes. I am confused by the idea that high ocean tides would exert a greater static load - weight - than low ocean tides. It seems to me that the weights in both cases would necessarily be identical because of the nature and origin of tides: gravitational shielding.
In LeSage graviton models, it is called "gravitational shadowing". Bodies shadow one another from some graviton impacts, and that is what results in the force of gravity. The expression "gravitational shielding" is a completely different concept, predicted to exist in LeSage-type models but never yet reliably detected.
In Lord Kelvin's analogy, the normal shadowing effect is like a swarm of bees crossing in front of the Sun. The total amount of sunlight blocked is proportional to the total number of bees. (Masses are made up of well-separated "matter ingredients" in the Meta Model, so that they are like a swarm of bees, being surrounded by mostly empty space.)
By contrast, if the bee swarm were <i>very</i> dense, two bees might be in line to block the same photon. In that case, only the first bee actually blocks the photon, and the presence of the second bee isn't noticed. So if we simply measured the total light blocked, we might underestimate the total number of bees. Likewise, measuring the external gravitational force of a body might underestimate the total number of matter ingredients if it could often happen that two of them were lined up so perfectly that they could block the same graviton.
So gravitational shielding is a decrease in the normal gravitational force expected from a body. The classical idea is that perhaps during solar eclipses, the Moon blocks not only all of the Sun's light, but also a small bit of its gravity too. That would be a gravitational shielding effect. It has never been detected, and in the June 15 <i>Meta Research Bulletin</i>, I showed that the Allais pendulum effect is not due to gravitational shielding.
> [dh]: I am neglecting the dynamic forces which are mostly tangential, or lateral for all practical purposes, which I can see could indeed contribute to earthquake inducing shakes rattles and rolls having been tossed by a wave or two myself.
However, the tangential forces are the only cause of ocean tides. The solid-body tidal forces lift land and water equally, and therefore cause no ocean tides. But when the Moon is west of the Atlantic Ocean, it pulls water free to flow westward, causing a piling up of Ocean water against our eastern shores. The extra water present at such times of course weighs more, and therefore contributes to ocean loading on the sea floor.
> [dh]: Wouldn't the density of a water column change with the shielding of the moon?
The amount of water present is changed by the horizontal forces that cause water to flow while land is held rigidly in place. But water can't be lifted by tides relative to the land, as you were probably thinking, even if water were a substance capable of changing density (which to good approximation it cannot do).
> [dh]: I realize this is conceptually the same as placing a 'roof' over the ocean, as in the above discussion, but I'm still confused by it. In the Meta Model, aren't the phenomena of gravity and gravitational shielding the same animal?
Gravity and gravitational <i>shadowing</i> are the same animal. Forget shielding because, even if it exists, it doesn't show up in any obvious detectable ways in everyday life.
Tides add to ocean loading because the Moon makes water (but not land) flow horizontally, which adds to the depth of the oceans in one direction while subtracting from their depth in the opposite direction.
Chapter 6 in <i>Dark Matter...</i> has a full explanation of the various kinds of tidal forces, and might prove beneficial for clearing up confusions about this matter. -|Tom|-
