In a year, which time period is the shortest at night? Why?

In a year, which time period is the shortest at night? Why? The summer solstice (June 22nd) is the most time in broad daylight, and the winter solstice solar term (65438+February 22nd) is the shortest time in broad daylight.

The winter solstice is the day with the least sunshine in a year. Generally, the solar terms of the winter solstice in the northern hemisphere are between 65438+February 2 1 and 65438+February 23, and 1 1 month is defined by the month of the winter solstice in the lunar calendar.

Every June 2 1 or so (20th to 22nd), the sun gradually reaches 90 degrees longitude of the Yellow River. This is the first clearly defined festival. In the 7th century AD, the ancients used earth gauges to measure the shadow of the sun, which was called "Little Summer" because of its shortest day.

Expanding materials: The sun basically shines on the Tropic of Cancer in summer, with the most daytime in the northern hemisphere, and it is difficult for the sun to set all day in the Arctic Circle and the south, resulting in a large total area of polar night areas.

After this day, the position of the sun moved south, the days in the northern hemisphere gradually shortened, the sun rose, and the position of the sunset gradually moved south. In the tropic of cancer and northern areas, the relative height of the sun is also decreasing at noon, and the shadow is gradually elongated. However, because the kinetic energy radiated by the sun to the road surface is still more than that radiated by the marble surface, the temperature will rise again in a short time.

According to the Records of Xiongxian County in the Republic of China, the traditional people in China will erect eight-foot table trees on the solstice in winter to test the drought and flood in the coming year. In the Han dynasty, there was also a norm of "water in advance and drought in retreat" to distinguish between flood and drought.

In addition, people in China will observe the changes of clouds and gases at sunrise and sunset from winter to day, and use rain eyes to distinguish the weather during the Spring Festival. Zhejiang folk proverb says: "The winter solstice is sunny and the solar terms are rotten, and the winter solstice is sunny for the Spring Festival." It shows that there is no rain and snow in the winter solstice solar terms, and it needs rain and snow in the Spring Festival, which makes the road muddy. or vice versa, Dallas to the auditorium

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