(n) the phenomenon whereby a small change at one place in a complex system can have large effects elsewhere, e.g., a butterfly flapping its wings in Rio de Janeiro might change the weather in Chicago
[牵一发而动全身 / 牽一髮而動全身, qiān yī fā ér dòng quán shēnㄑㄧㄢ ㄧ ㄈㄚ ㄦˊ ㄉㄨㄥˋ ㄑㄩㄢˊ ㄕㄣ] lit. pull one hair and the whole body moves; fig. a slight change will affect everything else; the butterfly effect#56355