The friendship between Chaplin and Einstein began with a movie, which is "Lights of the City". Chaplin made great efforts for this movie and politely asked Einstein to attend at the premiere, but Einstein liked this movie very much. At the last moment of the movie, Chaplin also found Einstein wiping his tears, and Chaplin was deeply touched, thus starting their friendship.

Chaplin and Einstein are famous friends in European history. Their relationship is very pure and profound, and they are not mixed with any personal interests, because they belong to different fields and their majors are very different.