Murphy's law

Murphy's Law (English Murphy 's Law ) is one on the U.S. engineer Edward A. Murphy, Jr. declining life wisdom that makes a statement about human error or on sources of error in complex systems.


Murphy's Law is

It probably goes to John W. Campbell Jr. (1910 - 1971) back (see Finagle's Law ) and was known worldwide as ' Murphy's Law '.

The engineer Captain Murphy took in 1949 during rocket sled program of the U.S. Air Force on a California test site in part, should be found out by which accelerations of the human body can endure. In a very costly experiment on the body of the subject 16 measuring sensors were attached. These sensors could be mounted in two ways: on the right and 90 ° deviation from this. The experiment failed because someone had all the sensors connected incorrectly. This experience prompted Murphy to formulate his law. The ' original version ' was:

A few days later Major John Paul Stapp quoted this at a press conference.

With Murphy's law mainly natural and engineering scientists have dealt. It is used in modern technology as a heuristic scale or as Experience for error prevention strategies ( inter alia, in computer science and quality assurance - fail-safe principle, eg reliability through redundant systems ) and makes the seemingly witty "law " on a very serious basis.

The reduced version of the Law ( " Whatever can go wrong, will go wrong " ) is also system-related, that is, it should only be used on closed systems or test configurations. Once it is in fact applied to future or unfinished actions or operations that are observed increasingly meddling by (as arranging perceived) factors which bring the "law" to falter, such as, but Stefan Klein has proved.

This manifests itself in daily life by the fact that usually not the worst happens, you but remember, especially in these rare cases, Murphy's Law (see also distorted perception ).

Author Ulf Heuner According to the Murphy has nothing left to do with law against entropy with random or chance, but by necessity. He cites as an example that if an old, dilapidated house eventually collapses, while this is done, the law of entropy, but not according to Murphy's Law. Crashes a house but just after construction, then was probably something went wrong. The paradox of Murphy's law is that for things that go wrong, always people were responsible in some way, but next to certain factors which are not within the power of individuals, help to ensure that something sometime (required) goes wrong. As such, factors he makes, for example, from uncontrollable acts of others, unconscious sabotage of our brain, our own, unrestrained will of our body or the famous Ticklish object. Under certain circumstances, all factors together could bring about the " disaster ".

Sometimes Murphy's Law is falsely attributed to the philosopher, theologian and amateur psychologist Dr. Joseph Murphy. One of his theories is, however:

Murphy's Law is often satirized. These parodies are similar to Murphy's law, but do not always have something to do with it and are meant rarely serious. A conciliatory complement of Murphy's Law reads: " ... and you can always find someone to take it back in order. "

A reversal of Murphy's Law is found in Yhprums law.


Since many people think rather pessimistic, notice and judge them mainly negative events. The positives are more natural for them and are less on (selective perception).

Example: "Whenever I go to work, I get into a traffic jam" - if it does not even know the whole thing is forgotten, and it is called the next time again: " ... again stuck in traffic, it is always the same. "

Also the effect of the illusory correlation can be used in this sense for the explanation, because the more eye-catching and rare events are often overestimated.


A study of Murphy's Law was awarded the 2003 Ig Nobel Prize.