EASY AND CRUSTY TIDAL MODELS
Hello All,
Here´s an interesting site with 2 explanations of the tidal issues.
I think we all can get some new information´s and see how these fits into our own ideas and approaches.
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Simple Tide Model -
http://www.seafriends.org.nz/oceano/tides.htm#simple - "The moon's gravity pulls a bulge of water towards it, compensated by an equal bulge on the opposite side".
This simple model has been used for centuries to calculate tide levels all over the world but it has a number of insurmountable problems.
• Wave speed: since the tide is just another gravity wave travelling along the ocean's surface, it must satisfy the laws for waves as explained in the wave chapter. For a wave to travel along the equator of 40,000 km in 25 hours, requires a speed of around 1600 km/hr, which is not sustainable. The maximum wave speed in a 'channel' of 5000m deep is about 800km/hr. Average depth of the ocean is around 3800m, demanding a lower speed still.
• Bouncing off continents: As the tide wave reaches a continent, most of it will be bounced back off the continental shelf, causing a tide wave of almost equal height to run in the opposite direction.
This is not observed in real life.
• Starting and stopping: as the tide wave apparently needs to start at one continent and stop at the other, it would be larger at the continent where it arrives and smaller where it came from. During the starting and stopping, far too much energy would be wasted.
This is not in accordance with tidal movements world-wide.
• Zero, one and two tides each day:
there are places without tide, with one tide and most with two tides each day. This cannot be explained.
• Tide height: the height of the tide, the difference between high and low tide, does not follow the two-bulge idea which suggests that the tide should be maximal around the equator or on opposite sides of a large ocean.
Near the equator one can find places without tides and places with near-maximal tides.
• Tide timing: high tide occurs at different times of the lunar cycle,
depending more on one's place on Earth than on the position of the moon.
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The balancing bulge on the other side is hard to explain.
There is obviously a better explanation of how tides move around the world.
The Buckling Crust Model - "The moon pulls the earth slightly oval. This buckle in the earth's crust travels at high speed. Tide waves form in a circular motion in the ocean basins" -
http://www.seafriends.org.nz/oceano/tides.htm#buckle
This new model does away with the objections mentioned for the simple model:
• Tide waves follow shorter paths in twelve hour rotations, never exceeding the maximum wave speed of about 800 km/hr.
• Tide waves do not bounce off continents by hitting them squarely. Instead, they follow along their coasts.
• There is no starting and stopping but a continuous motion. The standing waves absorb minimal energy.
• There is no balancing bulge. Instead, tide waves run in twelve hour circles.
• There can be none, one or two tides per day.
• The time of high tide depends both on the lunar cycle and the place on Earth.
• Tide waves are standing waves, expending the least energy.
Further interesting reading with illustrations here -
http://www.seafriends.org.nz/oceano/tides.htm and here -
http://www.seafriends.org.nz/oceano/waves.htm#wind
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AD: When reading this and the rest on the website, I think tidal motions are mostly connected to the Earth centrifugal motion as a generally "standing wave", combining with outsides pressures and celestial shadings, leaving "gravity" out of all equations.
So, how do these informations fits your tidal ideas and hypothesis???
Life makes senses and who could doubt it, if you have no doubt about it. - "Grooks" by Piet Hein - My fellow Danish countryman and also a Natural Philosopher