There is only day and no night.

The so-called extreme day means that the sun never sets and the sky is always bright. This phenomenon is also called white night. The so-called extreme night is the antonym of extreme day. The sun will never come out and the sky will always be dark. In the high latitudes of Antarctica, there is no life rhythm of "work at sunrise and rest at sunset", and there is no 24-hour alternation of day and night. The time of day and night alternation changes with the increase of latitude. The higher the latitude, the longer the extreme day and night. At 90 degrees south latitude, that is, in the Antarctic, the alternation of day and night is half a year, which means that the alternation of day and night lasts for a whole year, and half a year is a continuous day and half a year is a continuous night. In other continents, one day is equivalent to one year. If you leave the South Pole, the lower the latitude, it will no longer be a half-year day or a half-year night, and the time of extreme day and night will gradually shorten. At 80 south latitude, the alternation of day and night within 24 hours of 1 day only occurs outside the extreme value of day and night. If you are at the end of the extreme day, at first, the night time is very short, then the night time is getting longer and longer, until finally it is all night, and the extreme night begins. In the Antarctic circle (66 33' south latitude), only one whole day (24 hours) is full of day and the whole day is full of night. China Antarctic Great Wall Station (62 S13') is located outside the Antarctic circle. At one or two o'clock in the middle of the night in June+February, 5438, it was still bright, and people with good eyesight could still read and write. This extreme natural phenomenon of day and night also appears at the other pole of the earth, but at the opposite time to the South Pole. If the North Pole is in extreme daylight, the South Pole is in extreme night, and vice versa.

The formation of extreme day and night is caused by the earth's rotation around its own oblique axis when it revolves around the sun in an elliptical orbit. It turns out that when the earth rotates, the earth axis forms an inclination angle of about 23.5 with its vertical line, so the earth rotates for six months, and one pole always faces the sun, which is daytime; The other pole is far from the sun, and it is all night. This magical natural phenomenon of the North and South Poles is not found in other continents.