Why is the shadow from winter to the sun the longest?

China is a country in the northern hemisphere, and the direct point of the sun from the winter solstice is located in the Tropic of Capricorn. The farther north China is, the smaller the height of the sun at noon, and the longer the shadow. The northernmost part of China is located in the north of Mohe River in Heilongjiang Province, where the sun shadow is the longest at noon from winter to Sunday.

On the solstice of winter, the sun shines directly on the tropic of Capricorn. The winter solstice is also the shortest and longest day in a year in the northern hemisphere (north of the Tropic of Cancer). The arctic circle is in a state of permanent night, and the Antarctic circle is in a state of extreme day. From winter to the future, the position of direct sunlight began to move northward, the daytime hours in the northern hemisphere increased day by day, the sun height increased day by day at noon, and the sun shadow gradually shortened.

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In ancient times, people's understanding of solstice winter was:

When the cathode arrives, the yang begins to grow, the sun faces south, the days are short and the shadows are long, so it is called "winter solstice". As early as 2,500 years ago,

During the Spring and Autumn Period, China observed the sun with soil gauge to determine the winter solstice, which was the earliest of the 24 solar terms.

According to astronomical science, contrary to the summer solstice, when the sun shines directly on the tropic of Capricorn (also known as the winter solstice daily line), it is the most daytime in the northern hemisphere.

The shortest and longest day in the dark.

Among the major countries or regions with Chinese as the main body, the Macao Special Administrative Region is the only region that has designated winter solstice as a national public holiday. Kinmen county, under the jurisdiction of the government of the Republic of China, also implements the system of public holidays and public holidays, but Taiwan Province Island, Penghu Islands and Mazu Islands do not have holidays.

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