Everyone knows that anything that can go wrong will go wrong, but almost no one knows the Murphy behind the law. This episode travels to Muroc Army Airfield in the late 1940s, where Project MX981 used rocket sleds and hydraulic brakes to test how many Gs a human body could survive. Flight surgeon Colonel John Stapp rode the sled, and aerospace engineer Captain Edward A. Murphy Jr. supplied strain gauges that, in a 1949 chimpanzee trial, read exactly zero because they had been wired backwards.

We dig into the bitter disagreement over what Murphy actually said and meant, from George Nichols' account of an arrogant engineer blaming his assistant to the family's claim of a thoughtful safety maxim, and how Stapp's press conference launched the phrase as a philosophy of preparation before the public turned it into a pessimistic shrug. We also exa ...