Where “computer bug” actually comes from

The claim. A moth caught in a Harvard relay in 1947 is where the word “bug” came from for computer problems.

The check. The moth is real. Operators on the Harvard Mark II pulled it out of a relay and taped it into the logbook, with the note: “First actual case of bug being found.”

That sentence is the tell. “First actual case” only works if the word was already in use for faults in general, and this was the first time the fault happened to be a literal insect.

It was already in use. Thomas Edison, in an 1878 letter, wrote: ”'Bugs' — as such little faults and difficulties are called — show themselves and months of intense watching, study and labor are requisite before commercial success or failure is certainly reached.”

And it wasn't Edison's coinage either. “Bug” as a word for a mechanical defect is engineering slang going back well before him. The moth didn't name the thing. It just gave the metaphor a body.

Verdict. Myth, with a real moth inside it.

Sources. – Harvard Mark II logbook (the taped moth), Smithsonian National Museum of American History, object nmah_334663 – Thomas Edison, letter, 1878 – The Jargon File, “bug” — http://catb.org/jargon/html/B/bug.html

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