Why is winter the solstice when the northern hemisphere is close to the sun and summer the solstice when it is far away from it?

When the northern hemisphere is close to the sun, the sun shines directly on the tropic of cancer, not directly on the tropic of cancer. That is to say, at this time, the northern hemisphere of the earth is not directly exposed to the sun, but oblique, and gets less heat, so it is the winter solstice.

On the contrary, during the summer solstice, the sun shines directly on the Tropic of Cancer and the northern hemisphere, and the northern hemisphere gets more heat, so it is summer.

Extended data:

Winter solstice, also known as short day, short day, southern solstice and winter festival, winter solstice festival, Asian New Year, is both a solar term and a festival. The winter solstice is a solar term reflecting the direct sunlight movement. On the solstice of winter, the sun moves southward to the extreme, and the sun shines directly on the tropic of Capricorn, which is the place with the shortest day and the longest night in the northern hemisphere. From that day on, the direct sunlight point returned to the north, and the height of the sun in all parts of the northern hemisphere (China is located in the northern hemisphere) gradually increased, and the number of days also increased day by day.

The solstice in winter is the turning point of "South to North". For all parts of the northern hemisphere, the height of the sun rises and the sunshine gradually increases. According to the law of solar terms, beginning of spring is the starting point of the rising of "Yin and Yang" qi in Yang Qi. Since the beginning of spring, Yang Qi has changed and Yang Qi has risen. The beginning of spring marks the rebirth of everything and the beginning of a new cycle.

The solstice in winter is the starting point for the return of the sun. Since the winter solstice, the height of the sun has risen, and the day is getting longer and longer. The winter solstice marks the rebirth of the sun and the round-trip movement of the sun into a new cycle. Therefore, the ancients also regarded the winter solstice as a "good day". Among the eight festivals, the winter solstice is as important as New Year's Day in spring.