The original Murphy's Law was "If there are two or more ways to do something, and one of those ways can result in a catastrophe, then someone will do it." The law's author was Edward A. Murphy, Jr., a U.S. Air Force engineer, who, in 1947, was involved in a rocket-sled experiment in which all 16 accelerator instruments were installed in the wrong way, resulting in Murphy's observation. Murphy's Law is sometimes expressed as "Anything that can go wrong, will -- at the worst possible moment." In that format, the Law was popularized by science-fiction writer Larry Niven as "Finagle's Law of Dynamic Negatives " (sometimes known as "Finagle's corollary to Murphy's Law").