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A.Word.A.Day--Murphy's Law

Murphy's Law (MUR-feez law) noun

The facetious proposition that if something can go wrong, it will.

[Americanism, after a fictitious Murphy, allegedly the name of a bungling mechanic in U.S. Navy educational cartoons of the 1950s.]

"In the original, Jack Lemmon and Sandy Dennis played the Kellermans from Ohio, a nice couple whose trip to the Big Apple becomes the ultimate fulfillment of Murphy's Law when they lose their luggage, their hotel room, their money and their good names." Dann Gire, Get out & stay out!, The Daily Herald, Apr 2, 1999.

Here is a second opinion on Murphy's Law. This one is from The New Hacker's Dictionary, Third Edition, compiled by Eric S. Raymond. -Anu

Murphy's Law /prov./ The correct, *original* Murphy's Law reads: "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." This is a principle of defensive design, cited here because it is usually given in mutant forms less descriptive of the challenges of design for lusers. For example, you don't make a two-pin plug symmetrical and then label it `THIS WAY UP'; if it matters which way it is plugged in, then you make the design asymmetrical.

Edward A. Murphy, Jr. was one of the engineers on the rocket-sled experiments that were done by the U.S. Air Force in 1949 to test human acceleration tolerances (USAF project MX981). One experiment involved a set of 16 accelerometers mounted to different parts of the subject's body. There were two ways each sensor could be glued to its mount, and somebody methodically installed all 16 the wrong way around. Murphy then made the original form of his pronouncement, which the test subject (Major John Paul Stapp) quoted at a news conference a few days later.

Within months `Murphy's Law' had spread to various technical cultures connected to aerospace engineering. Before too many years had gone by variants had passed into the popular imagination, changing as they went. Most of these are variants on "Anything that can go wrong, will"; this is correctly referred to as Finagle's Law. The memetic drift apparent in these mutants clearly demonstrates Murphy's Law acting on itself!

This week's theme: syndromes, paradoxes, laws, and principles.

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