Murphy's LawMur·phy's Law
a facetiously pessimistic proposition stating that if there is a possibility for something to go wrong, it will go wrong
Origin of Murphy's Lawafter E. A. Murphy, Jr., United States engineer who formulated the original version (1949)
Any of certain humorous axioms stating that anything that can possibly go wrong, will go wrong.
Origin of Murphy's LawAfter Edward A. Murphy, (1918–1990), American engineer. Word History: Edward Murphy was an American engineer who designed sensors for measuring the forces involved in crashes. Used in rocket sled experiments in 1941, his sensors failed to function after another person installed them incorrectly. This experience is said to have prompted Murphy to utter the axiom that has since become associated with his name. Murphy may have spoken the axiom, but he did not invent it, because variations of it are attested from the early 1900s.
From Edward A. Murphy, Jr., a development engineer who worked for a brief time on the rocket sled experiments of the United States Air Force in 1948.