[Member (365WT)]answers [Chinese ]  Time :20191020  The effect of the lunar and sun's tidal forces on the ocean is the cause of seawater fluctuations, regardless of the weak effects of other planets. What kind of force is the tidal force? In physics, in the noninertial system, the tidal force is the universal gravitation of the moon and the inertia corresponding to it, as well as the universal gravitation of the sun and the inertial force corresponding to it. The combined force of force. Some sources mention that "centrifugal force" is also one of the components of tidal force. There is a centrifugal phenomenon in physics, but there is no concept and definition of "centrifugal force". However, the original meaning of "centrifugal force" is inertia. It can't be explained by the gravitational effect of the moon. Why does the high tide occur simultaneously in the two parts of the sea near the moon and the sea farthest from the moon, so that the spherical sea level becomes a spindle shape, as shown in the figure. Gravity is also the same. As of 2012, the most novel concept and definition of gravity appeared in the physics community. The definition is: "In the static range, the support or the object itself is a noninertial reference, gravity is The combination of the gravitational forces and the inertial forces of the object. "This definition can successfully explain the cause of tides.".It should be noted here that in the case of considering each planet as a mass point, when the gravity of the object on the ground is sought, only the universal gravitation of the object on the earth and the inertial force corresponding to the centripetal force of the object rotating with the earth participate in the calculation, and the other planets All gravity is offset by the corresponding inertia... The reasons for the formation of tides are as follows:
Let me talk about the role of the moon. Think of the earth and the moon as a mass point, and say that the moon makes a circular motion around the earth. In fact, the moon and the earth both make a circular motion around the common centroid of the two, but the earth's circular orbit is much smaller. (The two orbits of two planets with similar masses are approximately equal in circumference.) The center of the earth is a noninertial reference. The gravitational attraction of the Earth's mass point by the lunar mass is the centripetal force of the earth's mass around the common centroid, and the inertia of the centripetal force. The force is opposite to the magnitude of this centripetal force. Therefore, the earth's mass is offset by the gravitational attraction of the lunar particle and this inertial force. Since the earth is regarded as a particle, the trajectory and dynamics of the object on the earth can be regarded as exactly the same as the earth's particle. The gravitational attraction of the moon and the corresponding inertial force of the object are offset by each other. In fact, the size of the earth is very large. The orbital radius of the object on the ground closest to the moon, the circular motion of the moon and the common centroid of the moon is significantly smaller than the orbital radius of the earth's mass point. The universal gravitation of the object will be greater than the corresponding gravity. The inertial force, these two forces can no longer be offset, the resultant force and the object are opposite to the gravitational direction of the earth, making the gravity of the object significantly smaller. If the "object" is the sea water here, then there will be high tide here..Using the same method to study the objects on the ground farthest from the moon, the universal gravitation of the moon to the object is smaller than the inertial force corresponding to it, and the resultant force is opposite to the gravitational direction of the earth to the object here. Gravity is significantly smaller. Therefore, the seawater that is farthest from the moon will also have a high tide. This makes the spherical sea level slightly present in the shape of the spindle... Studying the effects of the sun on tides is the same as studying the effects of the moon. If you think that the earth is doing circular motion around the center of the sun, the problem is simple. It is not discussed in detail here. The occurrence of ground tides, tides and gas tides are caused by the above reasons, and the three have mutual influence. Because the moon is closer to the Earth than the Sun, the ratio of the Moon to the Sun is 11:5. For the ocean, the Moon is more pronounced than the Sun. The elasticity and plasticity of the crust at the bottom of the ocean causes tidal deformation, which causes the corresponding tides, that is, the influence of the tide effect on the tides; and the migration of seawater mass caused by the tides changes the load on the crust and makes the crust A reversible change has occurred. The gas tide is above the ocean tide, and it acts on the sea surface to cause its additional vibration, making the tide tide more complicated.
This energy is dissipated at a rate of 1.7 TW (1.7 x 10^12 W) by friction in shallow seas and coastal areas. That is, at the moment, the sun and the moon are on one side of the earth, so there is the greatest tidal force, so it will cause "great tide". Near the fifteen or sixteenth of the lunar month, the sun and the moon are on both sides of the earth. The tidal force of the sun and the moon will cause "great tide" when you push me; when the moon phase is the upper and lower strings, that is, the eighth and twentythird of the lunar calendar, the solar tidal force and the lunar tidal force cancel each other out. There was a "small tide", so there was a saying in the farmer’s squad that "the first fifteenth rises and the tide rises, and the first eightythree is everywhere to see the beach".In addition, there is also a high tide on the first day. As the moon moves eastward on the earth 13 degrees per day, the total is about 50 minutes, that is, the daily moon time (1 day = 24:50) is about 50 minutes delayed. (The next day, there will also be tidal water. There are usually two tides every day.) Therefore, the daily high tide is also delayed by about 50 minutes... 
