First of all, the laws of planetary motion

The orbit of 1. is elliptical, and the central celestial body is located in one of the two focuses of the ellipse, so there are pericentric points and apocentric points in the orbit. The revolution speed near the pericentric point is fast, and the revolution degree near the apocentric point is slow.

2. The radius of revolution (the connecting line between the revolving celestial body and the central celestial body) sweeps the same area per unit time.

3. The orbits of the eight planets in the solar system around the sun have the following characteristics: the directions are consistent (consistent with the direction of the earth's rotation); * * * Faceness (basically all on the ecliptic plane, and the sun is also on this plane); Proximity (orbit is not a perfect circle).

Second, the length of day and night and its changes and the important laws of local time

1. Day length+night length =24 hours; Where the sun rises-where the sun sets = the length of a day; Sunrise local time+day length ÷2= local time 12.

2. The terminator line is a big circle and always bisects the equator (also a big circle). Therefore, the equator is always equally divided day and night, and it is concluded that the intersection of the equator and the morning line is 6 o'clock, and the intersection of the dark line and the equator is 18. The central meridian of the solar hemisphere is the meridian where the direct light is located, and its local time is 12, while the local time of the central meridian of the night hemisphere is 0 o'clock. The same longitude means the same local time and the same local time means the same longitude. When the longitude difference is 15 degrees, the time difference is 1 hour, the longitude difference is 1 degree, and the local time is 4 minutes. The east is always earlier than the west. (Note: Local time has nothing to do with latitude)

3. If the sun shines directly into the northern hemisphere, the northern hemisphere will have long days and short nights in summer for half a year, and long days and short nights from south to north until the extreme days appear; When the sun shines directly into the southern hemisphere, it is half a year and one summer, with long days and short nights, and long days and short nights from north to south until the extreme day appears.

4. The length of day and night in a place and the height of the noon sun are determined by the local latitude and the latitude of the direct point. In a year, the direct point of the sun will pass through the same latitude twice (between the Tropic of Cancer), so the length of day and night somewhere on the earth is the same in these two days. For example, for local areas, the direct latitude of the sun is the same in early winter and early spring, so if the day in early winter is 9 hours and the night is 15 hours, so is the early spring. However, in the long summer and beginning of autumn, the local day length becomes 15 hours, and the night length is 9 hours (please analyze the latitude distribution of the direct sunlight point by yourself, and refer to the "Extracurricular Knowledge" column of this blog).

For a certain day, the length of day and night at the same latitude in the same hemisphere is the same. However, the length of day and night at the same latitude in different hemispheres is opposite. For example, at 45 degrees north latitude, the day is 9 hours long and the night is 15 hours long, so at 45 degrees south latitude, the day is 15 hours long and the night is 9 hours long.

Thirdly, the temporal and spatial distribution law of solar height.

1. When the sun shines on the earth, there is only one direct point. The direct point moves westward every hour in one day 15 degrees. Within a year, the direct point moves north and south between the two tropic lines.

2. The sun height at the direct point is 90 degrees, which is the largest sun height in the world. The farther away from the direct point, the smaller the height of the sun. The height of the sun in a certain place is determined by the spherical angular distance between the local and the direct point. The relationship is as follows: local sun height = 90 degrees-spherical angular distance between local and direct point. Therefore, when the distance from the direct penalty surface is equal, the height of the sun is the same. Therefore, the outline of the sun is a circle on the spherical surface with the direct point as the center, including the termination line.

3. The height of the sun is greater than zero in the daytime hemisphere, less than zero in the night hemisphere and less than zero at the terminal line.

4. The maximum height of the sun in a day is noon 12 o'clock (this is also the time when the sun is the highest in a day and is located in due north or south, and the shadow is the shortest and is located in due south or north. These phenomena can be used to judge whether the local time is 12 o'clock). The lowest height of the sun in a day is midnight.

5. In a day, the noon sun height angles around the world follow the law of point 2 above at different latitudes. It is symmetrically distributed with the straight latitude as the central axis and decreases from south to north. (Mastering this is very useful for calculating the noon sun height and calculating the latitude by using the noon sun height! )

6. Latitude of the direct point+latitude of the southernmost or northernmost point on the termination line (latitude of the latitude tangent to the termination line) =90 degrees.

7.90 degrees-(the height of the sun at noon somewhere-the height of the sun at midnight somewhere) ÷2 = local latitude.

8. On the equator (note: only on the equator), the angle between the termination line and the meridian = the direct latitude of the sun.

Fourth, the law of geostrophic deflection force

1. As an inertial force, geostrophic eccentric force has three major elements in mechanics: acting point, magnitude and direction.

2. The geostrophic deflection force acts on any moving object within the gravity range of the earth, and its magnitude is determined by the moving speed and latitude of the object. The faster the moving speed, the greater the geostrophic deflection, and the higher the latitude, the more obvious the effect of geostrophic deflection. Objects moving on the equator are not biased.

3. The direction of geostrophic deflection force is always perpendicular to the direction of motion of the object. The northern hemisphere points to the right of the object's motion direction (taking the motion direction as the front), and the southern hemisphere points to the left of the object's motion direction. The geostrophic deflection force only changes the motion direction of the object and does no work on the object, so it will not change the motion speed of the object.