Engels said: "When we carefully examine nature or human history or our own spiritual activities, the first thing that comes to our eyes is a picture that is endlessly intertwined with various connections and interactions." The whole world is a unified whole with universal connection, in which everything is conditionally connected with other things, and there are no isolated things. Universal connection is the basic condition for the existence and development of things. This is the root of the butterfly effect.
A small butterfly flapping its wings over a certain place disturbs the air, which may cause a storm in a distant place for a long time, which is a metaphor for the unpredictable and serious consequences caused by a small factor in long-term large-scale weather forecast. Small deviations are inevitable, which makes long-term weather forecast unpredictable or inaccurate. This is like playing billiards, chess and other human activities, which are often "a thousand miles away, a tiny difference" and "one careless move will lose the game."