Қателік болатын нәрсе, бола береді заңы

Adage typically stated as: "Anything that can go wrong, will go wrong"

Murphy's law is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong." In some formulations, it is extended to "Anything that can go wrong will go wrong, and at the worst possible time." Though similar statements and concepts have been made over the course of history, the law itself was coined by, and is named after, American aerospace engineer Edward A. Murphy Jr.; its exact origins are debated, but it is generally agreed it originated from Murphy and his team following a mishap during rocket sled tests some time between 1948 and 1949, and was finalized and first popularized by testing project head John Stapp during a later press conference. Murphy's original quote was the precautionary design advice that "If there are two or more ways to do something and one of those results in a catastrophe, then someone will do it that way." The law entered wider public knowledge in the late 1970s with the publication of Arthur Bloch's 1977 book Murphy's Law, and Other Reasons Why Things Go WRONG, which included other variations and corollaries of the law. Since then, Murphy's law has remained a popular (and occasionally misused) adage, though its accuracy has been disputed by academics. Similar "laws" include Sod's law, Finagle's law, and Yhprum's law, among others.

The perceived perversity of the universe has long been a subject of comment, and precursors to the modern version of Murphy's law are abundant. According to Robert A. J. Matthews in a 1997 article in Scientific American, the name "Murphy's law" originated in 1949, but the concept itself had already long since been known to humans. As quoted by Richard Rhodes, Matthews said, "The familiar version of Murphy's law is not quite 50 years old, but the essential idea behind it has been around for centuries. [ ] The modern version of Murphy's Law has its roots in U. S. Air Force studies performed in 1949 on the effects of rapid deceleration on pilots." Matthews goes on to explain how Edward A. Murphy Jr. was the eponym, but only because his original thought was modified subsequently into the now established form that is not exactly what he himself had said. Research into the origin of Murphy's law has been conducted by members of the American Dialect Society (ADS). Mathematician Augustus De Morgan wrote on June 23, 1866: "The first experiment already illustrates a truth of the theory, well confirmed by practice, what ever can happen will happen if we make trials enough." In later publications "whatever can happen will happen" occasionally is termed "Murphy's law", which raises the possibility that "Murphy" is simply "De Morgan" misremembered. ADS member Stephen Goranson found a version of the law, not yet generalized or bearing that name, in a report by Alfred Holt at an 1877 meeting of an engineering society. It is found that anything that can go wrong at sea generally does go wrong sooner or later, so it is not to be wondered that owners prefer the safe to the scientific  Sufficient stress can hardly be laid on the advantages of simplicity. The human factor cannot be safely neglected in planning machinery. If attention is to be obtained, the engine must be such that the engineer will be disposed to attend to it. ADS member Bill Mullins found a slightly broader version of the aphorism in reference to stage magic. The British stage magician Nevil Maskelyne wrote in 1908:

It is an experience common to all men to find that, on any special occasion, such as the production of a magical effect for the first time in public, everything that can go wrong will go wrong. Whether we must attribute this to the malignity of matter or to the total depravity of inanimate things, whether the exciting cause is hurry, worry, or what not, the fact remains. In 1948, humorist Paul Jennings coined the term resistentialism, a jocular play on resistance and existentialism, to describe "seemingly spiteful behavior manifested by inanimate objects", where objects that cause problems (like lost keys or a runaway bouncy ball) are said to exhibit a high degree of malice toward humans. In 1952, as an epigraph to the mountaineering book The Butcher: The Ascent of Yerupaja, John Sack described the same principle, "Anything that can possibly go wrong, does", as an "ancient mountaineering adage".

Differing recollections years later by various participants make it impossible to pinpoint who first coined the saying Murphy's law. The law's name supposedly stems from an attempt to use new measurement devices developed by Edward A. Murphy, a United States Air Force (USAF) captain and aeronautical engineer. The phrase was coined in an adverse reaction to something Murphy said when his devices failed to perform and was eventually cast into its present form prior to a press conference some months later – the first ever (of many) given by John Stapp, a USAF colonel and flight surgeon in the 1950s. From 1948 to 1949, Stapp headed research project MX981 at Muroc Army Air Field (later renamed Edwards Air Force Base) for the purpose of testing the human tolerance for g forces during rapid deceleration. The tests used a rocket sled mounted on a railroad track with a series of hydraulic brakes at the end. Initial tests used a humanoid crash test dummy strapped to a seat on the sled, but subsequent tests were performed by Stapp, at that time a USAF captain. During the tests, questions were raised about the accuracy of the instrumentation used to measure the g forces Captain Stapp was experiencing. Edward Murphy proposed using electronic strain gauges attached to the restraining clamps of Stapp's harness to measure the force exerted on them by his rapid deceleration. Murphy was engaged in supporting similar research using high speed centrifuges to generate g forces. During a trial run of this method using a chimpanzee, supposedly around June 1949, Murphy's assistant wired the harness and the rocket sled was launched. The sensors provided a zero reading; however, it became apparent that they had been installed incorrectly, with some sensors wired backwards. It was at this point a frustrated Murphy made his pronouncement, despite being offered the time and chance to calibrate and test the sensor installation prior to the test proper, which he declined somewhat irritably, getting off on the wrong foot with the MX981 team. George E. Nichols, an engineer and quality assurance manager with the Jet Propulsion Laboratory who was present at the time, recalled in an interview that Murphy blamed the failure on his assistant after the failed test, saying, "If that guy has any way of making a mistake, he will." Atomic Energy Commission Chairman Lewis Strauss was quoted in the Chicago Daily Tribune on February 12, 1955, saying "I hope it will be known as Strauss' law. It could be stated about like this: If anything bad can happen, it probably will." Arthur Bloch, in the first volume (1977) of his Murphy's Law, and Other Reasons Why Things Go WRONG series, prints a letter that he received from Nichols, who recalled an event that occurred in 1949 at Edwards Air Force Base that, according to him, is the origination of Murphy's law, and first publicly recounted by Stapp. An excerpt from the letter reads:

The law's namesake was Capt. Ed Murphy, a development engineer from Wright Field Aircraft Lab. Frustration with a strap transducer which was malfunctioning due to an error in wiring the strain gage bridges caused him to remark – "If there is any way to do it wrong, he will" – referring to the technician who had wired the bridges at the Lab. I assigned Murphy's law to the statement and the associated variations.

From its initial public announcement, Murphy's law quickly spread to various technical cultures connected to aerospace engineering. Before long, variations of the law applied to different topics and subjects had passed into the public imagination, changing over time. Arthur Bloch compiled a number of books of corollaries to Murphy's law and variations thereof, the first being Murphy's Law, and Other Reasons Why Things Go WRONG, which received several follow ups and reprints. "Mrs. Murphy's law" is a corollary of Murphy's law, which states that "Anything that can go wrong will go wrong while Mr. Murphy is out of town." The term is sometimes used to describe concise, ironic, humorous rules of thumb that often do not share a relation to the original law or Edward Murphy himself, but still posit him as a relevant expert in the law's subject. Examples of these "Murphy's laws" include those for military tactics, technology, romance, social relations, research, and business.