Tides

Twice a day in the terrestrial seas and oceans, tides occur and with the same regularity twice a day they are replaced by ebbs. The reason for these well-known phenomena is the attraction that all parts of our planet experience from the Moon.

Twice a day in the terrestrial seas and oceans, tides occur and with the same regularity twice a day they are replaced by ebbs

It is quite easy to understand the nature of tides. The water shell Earth has a spherical shape. So it would be (in the first approximation), if the Moon did not exist at all. Suppose now that the moon suddenly appeared. It will attract to itself both the solid body of the Earth, and various parts of its water shell. All these parts will move in the direction of the Moon. Displacements will depend on the distance of this or that part of the Earth to the center of the moon. The greatest acceleration and therefore the greatest displacement will be a part of the water shell facing the Moon. A slightly smaller displacement will occur near the solid body of the Earth, whose mass can be considered concentrated at its center. Finally, the "rear" part of the water shell will move even less.

As a result of these unequal displacements, there are tides: the water shell will stretch in the direction of the Moon. Since the displacement of the Earth's solid body is greater than the displacement experienced by the "back" part of the water shell, a second tidal hump is formed on the "rear" part of the Earth.

The tidal effect of other planets on the Earth is negligible, but the Sun causes both in the Earth's hydrosphere and in its solid body tides, only 2,2 times inferior in amplitude to the lunar one.

The axis of the solar tides is directed toward the Sun, the axis of the lunar tides is toward the Moon. The angle between these directions is continuously changing. When they coincide (and this occurs on the full moon and the new moon), the Sun and the Moon act together and the total amplitude of the lunar-solar tides becomes greatest. On the contrary, in the first and last quarters the Moon and the Sun act "in disagreement" and the amplitude of the tides is the smallest.

Solar tides in the solid body of the Earth are small - the maximum height of a solid tidal wave excited by the Sun does not exceed 13 cm. But, acting together with the Moon, the Sun on a full moon or new moon can lift us by 43 cm. True, the hard tides are quite flat and twice in day people "sway" on the solid tidal waves. It would seem that ebbs and tides are purely earthly phenomena, but in the solid body of the Moon, the Earth excites tides, which inevitably should affect the evolution of the Earth-Moon system.

Friction of the tides on the hard surface of the globe gradually slows down its rotation. Pass "some" fifty billion years, and the Earth, as the calculations show, how would it stop. The day will be equal to the month, or rather the Earth will be constantly facing the Moon with the same side, and it will complete a complete revolution around its axis during the same time that the Moon will wrap around the Earth.

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