Reasons for liking the summer solstice
Solstice is the earliest of the 24 solar terms. In the 7th century BC, the shadow of the sun was measured by civil soil gauge, thus the summer solstice was determined. According to "Zunxian Manuscript", "The sun arrives in the north, the days are long and the shadows are short, so it is called the summer solstice. At best, it is excellent. " From summer to sunrise, the sun directly reaches the northernmost point of the year, almost directly to the Tropic of Cancer (23 26' north latitude), which is the longest place in the northern hemisphere. The higher the latitude, the longer the day. For example, the daily length of Haikou in Hainan is a little more than 13 hours, Hangzhou is 14 hours, Beijing is about 15 hours, and Mohe in Heilongjiang can reach 17 hours. North of the Arctic Circle, the sun is above the horizon all day, which is the widest day in the northern hemisphere. At the same time, for the Tropic of Cancer and its north, the summer solstice is also the day with the highest sun height at noon in a year. In Beijing, the height of the sun is as high as 73 32' at noon from summer to Sunday. On this day, the northern hemisphere received the most solar radiation, almost twice as much as the southern hemisphere. At this time, the southern hemisphere is in the middle of winter.
Astronomical experts say that the solstice in summer is the turning point of the sun, and then it will go back. After the summer solstice, the direct point of the sun gradually moved southward, and the days in the northern hemisphere began to shorten gradually. For the Tropic of Cancer and its northern area, after the summer solstice, the height of the noon sun began to decrease day by day. There is a folk saying that "eating noodles in summer makes the day shorter", and Wei, a poet in the Tang Dynasty, once wrote that "the sundial is cloudy, and the night leakage is long from now on".
In ancient China, the summer solstice was divided into three phases: "The first phase of staghorn dissolution; Second, wait for cicadas to start singing; Third-class Pinellia ternata. " Although elk and deer belong to the same family, the ancients thought they belonged to yin and yang. The deer's horn faces forward, so it belongs to Yang. On the solstice of summer, Yin Qi was born, and Yang Qi began to decline, so the front antlers began to fall off. However, the elk is cloudy, so it falls off at the corner from winter to Sunday; After the solstice of summer, the male cicada fluttered and sang because of Yin Qi's feeling; Pinellia ternata is a shade-loving herb, named after it was born in swamps or paddy fields in midsummer. It can be seen that in the hot summer, some yin-loving creatures began to appear, while positive creatures began to decline.