Edward A. Murphy was an engineer working on Air Force Project MX981 in 1949, designed to see how much sudden deceleration a person can stand in a crash.
One day, after finding that a transducer was wired wrong, he cursed the technician responsible and said, "If there is any way to do it wrong, he’ll find it."
The contractor’s project manager kept a list of "laws" and added this one, which he called
Murphy’s Law.
We know it better today as "if anything can go wrong, it will."