Halfway through the winter solstice, the heavenly heart has not changed. What do you mean?

This means that when the winter solstice is half of the second month, everything in the universe enters a moment that is neither dynamic nor static. "Tianxin has not changed" is extremely smooth, with a vacuum in the middle. The state of vacuum is before the first movement of yang, that is, "when everything is not born."

This famous sentence "Half a winter solstice, the heavenly heart has not changed." When the sun first moves, everything is lifeless. "Shao Kangjie (Shao Yong), an expert in the Book of Changes in the Song Dynasty.

The winter solstice in a year is like the middle of the day, which is twelve o'clock at night. Everything is calm, but it is ready to go. The nearest sun is summer, and the farthest sun is winter. It can also be said that in summer, the yang is the most abundant and the yin is the weakest; In winter, yang is the weakest and yin is the most abundant.

Extended data:

Around the winter solstice, the earth is located near the perihelion, which makes the time of the sun in the southern hemisphere about 8 days shorter than that in the northern hemisphere, so the winter in the northern hemisphere is slightly shorter than that in summer. The solstice in winter is the turning point of the sun. After this day, I went back, and the direct sunlight point began to move northward from the tropic of Capricorn (23 26' s), and the daytime in the northern hemisphere increased day by day.

In fact, strictly speaking, the winter solstice solar terms reflect the deviation law of direct sunlight on the earth's surface. The arrival of the winter solstice solar terms marks the shortest day in a year in all parts of the northern hemisphere, and is not the highest day in Yin Qi in the concept of Yin and Yang. Yin-yang and five elements belong to the category of "stem and branch", and the rise and fall of "Yin-yang" is based on "stem and branch".