Influence of Winter Solstice on Earth's Rotation and Revolution

The winter solstice is the southernmost day of the year. After this day, the direct point of the sun began to move northward from the tropic of Capricorn, and the length of the day in the northern hemisphere began to increase gradually, and the height of the sun also increased gradually at noon.

It is worth noting that around the winter solstice, the earth is located near the perihelion, and its movement speed is slightly faster, which leads to that the time of the sun in the southern hemisphere is about 8 days shorter than that in the northern hemisphere, so the winter in the northern hemisphere is slightly shorter than that in summer.

Note: The polar axis passes through the center of the earth and connects the north and south poles, making an angle of 66 34 ′ with the orbital plane of the earth revolution and perpendicular to the equatorial plane.

Extended data

After the solstice in winter, the days are long and the nights are short. On the day of winter solstice, the height of the sun at noon in the northern hemisphere is also the lowest. For example, in Beijing, the height of the sun is only 26 42', because the shadow at noon is the longest, so it is also called "growing to the sun".

China attached great importance to the winter solstice in ancient times, and stipulated that the same month as the winter solstice was the "sub-month", which was the first branch of the twelve solar terms. Therefore, the winter solstice is still a traditional festival, commonly known as "Winter Festival" and "Dragon Solstice Festival".