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.

Murphy's Law is often mistaken for Finagle's Law.

In 1949, the US Air Force was running a test series (Project MX981) to see what sort of acceleration (or G-forces) a human being could withstand. They were using a volunteer strapped into a rocket sled at what is now called Edward's Air Force Base, in California. The sled would accelerate up to about 1,000 kilometres per hour, and then stop suddenly. One of the volunteer human torpedoes was Colonel Stapp, who was also a medical doctor.

Now our hero, Air Force Captain Edward A. Murphy Jnr., had designed a harness which strapped onto the volunteer. This harness held 16 sensors to measure the acceleration, or the G-forces, on different parts of the poor volunteer. As luck would have it, there were two ways that each sensor could be installed.

The rocket sled took off, and stopped suddenly, generating 40 Gs. Under 1 G, the average person weighs about 70 kg, but under 40 Gs, they weigh 40 times more - about 2.8 tonnes. 40 Gs is an enormous amount of acceleration - enough to push your ears onto the front of your head.

At the end of the experiment Colonel Stapp staggered off the rocket sled with blood-shot eyes and bleeds from a number of bodily orifices. When he looked at the results, he wasn't very happy - all the sensors registered zero! He called for Captain Murphy, who examined the sled - and found that every single one of those 16 sensors had been installed the wrong way round. Colonel Stapp had been strained in vain.

In a voice like thunder, Edward A. Murphy Jnr. proclaimed, "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". This is the true and original form of Murphy's Law.

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