The phrase of the population of sudong hill, “the moon is cloudy and the matter is too difficult to complete”, is an expression of an objective cycle of change without the will of the people. There are two reasons for the change in the monthly cycle: the cyclical “joining movement” of the moon, the earth and the sun; the moon itself does not send visible light, and what we see is only the part of the moon that is luminous。
As the moon rotates around the earth, it also turns around the sun together with the earth, and its visual motion against the sun is therefore a union sport. When the moon runs between the earth and the sun, and the heart of the moon is the same as that of the sun (set as the first year of the agricultural calendar), the dark hemisphere, where the moon is not luminous, is called a stale or new moon. Subsequently, the gap between the lunar and the sun's yellow strokes gradually widened, moving eastward, and the sunset in the west saw the small part of the moon lit up by the sun in the form of a moustache to the sun. When the difference between the moon and the sun is 90 degrees, we see the moon in half a circle, called the upper chord, half of the hemisphere lit by the sun. Then we saw more parts of the moon lit by the sun. When the difference between the lunar and the sun is 180° (fifteen or sixteen times a month), it can be seen that the entire hemisphere, which is luminous by the sun, is in circular shape, called full moon or vision. After that, we saw the part of the moon lighted by the sun, and when the difference between the moon and the sun was 270 degrees, we saw a half circle in the other hemisphere of the moon lit by the sun, known as the next chord, followed by a sickle “muted moon” in the direction of the sun before dawn。
After a long month of hope, the next new month and the renewed month began to change. Although we see only the part of the moon that is lit by the sun in the light of the moon, the rest of the moon that is not lit by the sun is not completely dark, and it is still rare to see the grey part of the moon, especially with a strong light telescope. The grey light of the moon is due to the fact that the earth reflects a small amount of sunlight to the back of the moon。
In secondary and primary schools, the sun, the earth, the moon three operators are commonly used to demonstrate their assembly movements and the principles of daily and monthly foods, while the reality is much more complex and it is difficult to map accurately proportionately, while similar maps can illustrate some of the situations. It's a situation that imagines itself from an alien perspective。
The orbit of the moon around the earth, known as the “white-channel”, has an average intersection of 5° 8' 4342' with the earth around the sun's common orbital surface (“the ecstasy”), and the alternation of the ecstasy with the ecstasy is ±9' in 173 days. The large circle that intersects with the sky is called the "white track" and, observed from earth, each of the moon's "star moons" moves around the white lane. There are two points of contact between the white and zodiac: the “uppoint” of the moon from the south to the north through the zodiac and the “downpoint” from the north to the south through. The lunar orbit has a perigee connected to an apogee — the arch line has also been moving from west to east for a period of 8. 849 years. Measured by different benchmarks, the orbital cycle of the moon has four expressions: the moon is based on a cycle of stars, with the moon orbiting the earth in a circle, and in reality the moon is a cycle of 27. 32166 days (“the day” is “the day of the sun”); the near point of the moon is two consecutive times between the nearness of the moon and 27. 55455 days; the three points of the moon are between two consecutive elevations of the moon and 27. 2222 days of the first; and the prospective moon is a cycle of moon-to-month change, which is a combination cycle with the sun in which the moon and the earth's heart is yellow twice (sorgan) with a peak of 29. 53059 days。
A solar eclipse is possible only when the moon is close to a “sweet” line that coincides with a ecstasy. Other “sweet” times, because the moon is far from the zodiac, there will be no eclipse。
The orbit of the moon around the earth and the earth (ball)-lunar system around the sun is elliptical, with a distance of 0. 9832603 to 1. 0167056 astronomy unit (1 astronomical unit = 1495,997. 87 million km) and a distance of approximately 356,400 to 406,700 km, correspondingly with a diameter of 31 " 28" for the sun in the eye (known as the sun wheel) the angle of the moon's face is changed by 29, 22, 26。
Because the moon does not send visible light, the light from the sun (daily wheel) is followed by the formation of a “book shadow” that cannot be fully exposed to the sun's light and a “half shadow” that is partially exposed to the sun's light. The moon book is conical and varies in length from 366,900 to 379,700 km. A comparison of these values leads to: the peaks of the moon book cone can sometimes reach or exceed the surface of the earth and sometimes the surface of the earth. As a result, three types of daily diet occur, depending on the interaction of the earth's surface with the moon book cone:
(1) daily diet. The earth's surface is beyond the surface of the moon plate, and the earth's surface is completely invisible, i. E. The moon completely covers the wheel. This is the best opportunity to observe the dim sun's atmosphere — the colour ball and the corona。
(2) the eclipse. The upper end of the moon book cone does not reach the earth's surface, but the outer ring of the day's wheel, which covers most of the centre of the day's wheel, is visible in the ground area of its extended “false shadow”. If the rings are very thin, you can see "belly pearl."。
(3) daily diet. Only part of the day-wheel, that is, only part of the day-wheel, was seen in the ground area of the half of the moon. In one case, the moon itself is completely alienated from the earth, only half of the shadow intersects with the earth's surface, and the whole planet is unable to see the whole or the whole of it. In other cases, the solar diet was observed in the moon's semi-film zone during the eclipse or eclipse。
In addition, there is an “all-round diet” for the planet as a whole, because, throughout the planet's daily diet, the peak of the moon book cone does not reach a certain part of the ground in a small part of time, while the other part exceeds a certain part of the ground. In fact, because of the rapid movement of the moon's vision, both the original and the semi-image of the moon have swept the earth's surface in a local area — this and the semi-video. The tape can be approximately 270 km wide and the half-band can be about 7,000 km wide。
