In 1947, an aerospace engineer named Edward A. Murphy Jr was involved in high-speed rocket sled experiments led by the US Air Force. The aim of the experiment was to research the effect of sudden deceleration on the human body so to improve the safety of jet fighter pilots. To study this, a flight surgeon named Dr John Stapp devised a “sled” attached to a rocket that could be used on a long track. The rocket would propel the sled to a massive speed and brakes would induce as sudden deceleration. However, they found that the machines that were used to measure the G-force (force of deceleration relative to the force of gravity) were unreliable. Murphy proposed that they use electronic strain gauges attached to the harness of the test subject to measure the G-force, something he learned while working with centrifuges.
The idea was great but there was one problem: the gear kept failing, showing no reading whatsoever. Murphy soon found that the sensors were attached correctly but were wired backwards. This simple mistake frustrated Murphy, who blamed the incompetency of his assistant, stating that “if that guy has any way of making a mistake, he will.” This became the famous Murphy’s law, now simplified to “Anything that can go wrong will go wrong”.
Murphy’s law actually played a fundamental role in defensive design, where the worst-case scenario is always assumed and prepared for. Thanks to this system, the rocket sled experiment was successful and in 1954 Dr Stapp became the fastest man in the world – travelling at a speed of 1011km per hour and decelerating at a force of 46G (it was hypothesised that a human being could not survive past 18G). Not only did he survive (albeit with broken limbs, ribs, hernias, detached retina and temporary blindness), Dr Stapp went to build bigger rockets to further test the limits of the human body.
Interestingly, there’s another side to the Murphy’s law involving psychology. People suffer from a fallacy called appeal to probability, where they believe that because there is a possibility of something can happen, it will happen. The brain is surprisingly inefficient in dealing with probabilities and has a tendency to ignore that there is a relatively miniscule possibility and instead focuses on the absolute fact that there “is” a probability. This is the best explanation for why people are compelled to buy lottery tickets and why every student believes they will grow up to be rich and successful.