What is the introduction of solar terms after the Millennium?

2. After the autumnal equinox, the short days and long nights will become more and more obvious, the temperature difference between day and night will gradually increase, and the temperature will continue to drop. The ancients believed that thunder was due to strong yang, and after the autumnal equinox, yin gradually flourished and yang declined, so thunder began to stop. Waiting for insect bites. "Blank" is fine soil. After the autumnal equinox, the weather turned cold, and the secluded insects began to drill into the hole. At the same time, they will seal the hole with fine soil to resist the invasion of cold.

3. The water began to dry up, dry in autumn, rainfall decreased, and water vapor evaporated quickly. The amount of water in rivers and lakes has dropped sharply, and some puddles and swamps may even dry up. It can be seen that the temperature drops day by day after the autumnal equinox, and it gets colder every day; The temperature difference between day and night is gradually increasing, which may be higher than 10℃.