tickle the dragon's tail

== English == === Etymology === From the obvious risk of tickling a dragon's tail. In physics, it was coined by American physicist Richard Feynman to describe the experiments of Louis Slotin at Los Alamos National Laboratory. === Pronunciation === === Verb === tickle the dragon's tail (third-person singular simple present tickles the dragon's tail, present participle tickling the dragon's tail, simple past and past participle tickled the dragon's tail) (idiomatic) To do something that has a risk of going catastrophically wrong. (idiomatic) To annoy an irritable person. (nuclear physics) To bring two subcritical masses close together in order to find the edge of criticality. ==== See also ==== criticality accident