How Murphy's Law Works

Who was Captain Edward A. Murphy Jr.?

Col. John Paul Stapp aboard the “Gee Whiz” rocket sled at Edwards Air Force Base.
Col. John Paul Stapp aboard the “Gee Whiz” rocket sled at Edwards Air Force Base.
Photo courtesy Edwards Air Force Base

Believe it or not, there really was a Murphy, and he lived in the United States until his death in 1990. Captain Edward A. Murphy Jr. was an engineer in the Air Force. Although he took part in other engineering design tests throughout both his military and civilian careers, it was one test that he attended -- almost as a fluke -- that gave rise to Murphy's Law.

In 1949, at Edwards Air Force Base in California, officers were conducting project MX981 tests to determine once and for all how many Gs -- the force of gravity -- a human being could withstand. They hoped that their findings could be applied to future airplane designs.

The project team used a rocket sled dubbed the "Gee Whiz" to simulate the force of an airplane crash. The sled traveled more than 200 miles per hour down a half-mile track, coming to an abrupt stop in less than a second. The problem was that, in order to find out just how much force a person could take, the team needed an actual person to experience it. Enter Colonel John Paul Stapp. Stapp was a career physician for the Air Force, and he volunteered to ride the rocket sled. Over the course of several months, Stapp took ride after physically grueling ride. He was subjected to broken bones, concussions and broken blood vessels in his eyes, all in the name of science [source: Spark].

Murphy attended one of the tests, bearing a gift: a set of sensors that could be applied to the harness that held Dr. Stapp to the rocket sled. These sensors were capable of measuring the exact amount of G-force applied when the rocket sled came to a sudden stop, making the data more reliable.

There are several stories about what happened that day, and about who exactly contributed what to the creation of Murphy's Law, but what follows is a good approximation of what happened.

The first test after Murphy hooked up his sensors to the harness produced a reading of zero -- all of the sensors had been connected incorrectly. For each sensor, there were two ways of connecting them, and each one was installed the wrong way.

When Murphy discovered the mistake, he grumbled something about the technician, who was allegedly blamed for the foul-up. Murphy said something along the lines of, "If there are two ways to do something, and one of those ways will result in disaster, he'll do it that way" [source: Improbable Research].

Shortly thereafter, Murphy headed back to Wright Airfield where he was stationed. But Stapp, a man who was known for his sense of humor and quick wit, recognized the universality of what Murphy had said, and in a press conference he mentioned that the rocket sled team's good safety record had been due to its awareness of Murphy's Law. He told the press that it meant "Whatever can go wrong, will go wrong" [source: The Jargon File].

That was all it took. Murphy's Law turned up in aerospace publications and shortly thereafter made its way into popular culture, including being made into a book in the 1970s.

Since then, the law has been added to and expanded upon. In the next section, we'll look at some of Murphy's Laws interpretations and consequences.