What does autumn dew mean when autumn frost falls? What, what, what, four solar terms

"Autumn dew" refers to: beginning of autumn, early summer, white dew and autumn equinox.

Beginning of autumn is the first 13 solar term in 24 solar terms, and "autumn" means that summer is cool, which means the beginning of autumn.

Summer is the first 14 of the 24 solar terms. The node time is around August 23rd in Gregorian calendar, and the sun arrives at 150.

The Millennium is 15 of the 24 solar terms. The weather is getting colder and colder, and there are many dewdrops on the ground and leaves in the morning.

The autumnal equinox is the16th solar term among the 24 solar terms, which usually falls on September 22nd or 23rd every year.

The source of the twenty-four solar terms

"Twenty-four solar terms" is the product of ancient farming civilization. It is a knowledge system formed by ancient ancestors following the farming season and observing the movement of celestial bodies to understand the changing laws of seasons, climate and phenology in a year. The twenty-four solar terms were originally formulated according to the changes of stars. The Big Dipper rotates once and bucket handle rotates once clockwise, which is called one of the "years" (Figure).

The current "twenty-four solar terms" are formulated according to the position of the sun on the return to the ecliptic, that is, the annual movement track of the sun is divided into 24 equal parts, each 15 is 1, and each 1 is a solar term, starting in beginning of spring and ending in severe cold.