What is dichotomy?

The vernal equinox refers to the vernal equinox and the autumn equinox. These two days are rainy, so the sunshine time of the earth, that is, day and night, is equal, with 12 hour. Meanwhile. The range of the sun's exposure on this day. It happens to be a warped curve circle that passes through the North Pole and the South Pole. Therefore, there will be days and nights of the same length in the polar circles of the North Pole and the South Pole.

On the solstice in winter, because the direct point of the sun is on the tropic of Capricorn, there will be an extreme day in the Antarctic circle and an extreme night in the Arctic circle.

In summer, because the direct point of the sun is in the Tropic of Cancer, there will be an extreme day in the Arctic Circle and an extreme night in the Antarctic Circle.

Related information:

The vernal equinox is one of the 24 solar terms and the fourth solar term in spring. The fingers do not match, the longitude of the sun reaches 0, and the festival is held on March 19-22 of the Gregorian calendar every year. The vernal equinox is of great significance in astronomy. On this day, the northern and southern hemispheres are divided equally day and night. Since then, the direct position of the sun has continued to shift from the equator to the northern hemisphere. The days in the northern hemisphere are longer than the nights, while the southern hemisphere is the opposite. In terms of climate, there are also obvious characteristics. In addition to the Qinghai-Tibet Plateau, Northeast China, Northwest China and North China, China has entered a beautiful spring.

The significance of the vernal equinox, first, refers to the equal division of day and night, each of which is 12 hours; Second, in ancient times, it was spring from beginning of spring to long summer, and the vernal equinox happened to be in the three months of spring, and spring was equally divided. After the vernal equinox, the climate is mild, rainy and sunny. During the vernal equinox, there are some folk customs in China, such as flying kites, eating spring vegetables and laying eggs.