   the point of no return is the point beyond which one must continue on one's current course of action because turning back is physically impossible, prohibitively expensive or dangerous. a particular irreversible action (e.g., setting off an explosion or signing a contract) can be a point of no return, but the point of no return can also be a calculated point during a continuous action (such as in aviation). == origins and spread of the expression == the term pnrâ"point of no return," more often referred to by pilots as the "radius of action formula" â originated, according to the oxford english dictionary, as a technical term in air navigation to refer to the point on a flight at which, due to fuel consumption, a plane is no longer capable of returning to the airfield from which it took off. the first major metaphorical use of the term in popular culture was in the 1947 novel point of no return by john p. marquand. it inspired a 1951 broadway play of the same name by paul osborn. the novel and play concerned a pivotal moment in the life of an american banker, but they also explicitly referenced how the original expression was used in world war ii aviation. ==related expressions== there are a number of phrases with similar or related meaning: the point of safe return (psr) is the last point on a route at which it is possible to return to the departure airfield arriving back with the required fuel reserves still available in the tanks. continuing past the psr you are now committed to landing at your destination. *"beyond a certain point there is no return. this point has to be reached." this statement appears in betrachtungen Ã¼ber sÃ¼nde, leid, hoffnung und den wahren weg ("reflections on sin, suffering, hope and the true way") by franz kafka. *"crossing the rubicon" is a metaphor for deliberately proceeding past a point of no return. the phrase originates with julius caesar's seizure of power in the roman republic in 49 bc. roman generals were strictly forbidden from bringing their troops into the home territory of the republic in italy. on 10 january, caesar led his army across the rubicon river, crossing from the province of cisalpine gaul into italy. after this, if he did not triumph, he would be executed. therefore the term "the rubicon" is used as a synonym to the "point of no return". *"alea iacta est" ("the die is cast"), which is reportedly what caesar said at the crossing of the rubicon. this metaphor comes from gambling with dice: once the die or dice have been thrown, all bets are irrevocable, even before the dice have come to rest. the following expressions also express the idea of a point of no re
Metaphors_referring_to_places Social_psychology