expression
the world is constantly changing
A literary yojijukugo from a Chinese legend, expressing that the world undergoes profound transformations over time, like a mulberry field turning into a blue sea. Rare in modern conversation; used in classical or poetic contexts.
「桑田碧海」という言葉は、世の中の大きな変化を表す故事成語だ。
The phrase '桑田碧海' is a classical idiom that expresses great changes in the world.
From a Chinese legend recorded in the 'Shenxian Zhuan' (Biographies of Immortals), where a goddess describes how the Eastern Sea has turned into mulberry fields multiple times, symbolizing the vast changes over eons. The exact historical derivation is uncertain, but the phrase is conventionally associated with this story.