The traditional solar terms of the equinox between day and night

The vernal equinox refers to the position of the sun between 0 degrees and 15 degrees of the yellow meridian during the period from March 20th to April 5th. But in fact, it usually refers to the day when the sun is really located at 0 longitude of the Yellow River.

In a daze → vernal equinox → Qingming

The autumnal equinox is another solar cycle, that is, the period when the sun lies between 180 and 195, usually from September 23rd to June 8th. But the same, in fact, refers to the day when the sun is really at longitude 180.

White dew → autumnal equinox → cold dew

Grammar, logic, rhetoric, facts and tables

In Latin vocabulary, the plural of nox is noctes. Although this form still exists in English possessive equinox, complex equinox is more commonly used than equinox.

One effect of the cycle of day and night is to temporarily destroy the function of communication satellites. For most synchronous satellites, there is always a dead angle: when the sun is behind the earth relative to the satellite, the sun will be covered by the earth, but the powerful energy and wide radiation spectrum of the sun will exceed the signal received by the ground radio station to produce noise, which will temporarily interfere with or suppress the transmission of the circuit according to the size of the antenna and other factors. These effects can last from a few minutes to an hour.

During the period around the vernal equinox, synchronous satellites will enter the shadow of the earth, so the solar cells that provide electricity will temporarily stop running around midnight because they can't be illuminated by sunlight.

Many European folklore can lay eggs on the equal day of night and day in March, and some areas will join the equal day of night and day in September, but some of them are completely denied. Taiwan Province Province is very popular during the Dragon Boat Festival and the summer solstice. )