The first "bug" in computing was a real bug. The part of the story most people get wrong is the part that matters.
On September 9, 1947, a team working on the Harvard Mark II computer found a moth wedged between the contacts of a relay, and the machine had stopped. They pulled it out, taped the dead insect into the computer's logbook, and one of the team wrote the most famous margin note in computing history: "First actual case of bug being found."
The twist: they didn't coin the word. Engineers had been calling small mechanical flaws "bugs" for decades before the first computers, and Thomas Edison was writing about bugs in electrical circuits in the 1870s. The Mark II incident didn't invent the term — it gave it a picture, a literal insect you could hold, which is why the story stuck.
One footnote, because it's true and it's kind. The logbook probably wasn't Grace Hopper's; it was the machine's log. But she was on that team in 1947, and she told this story so often and so well in her public lectures that the note is usually remembered as hers. Her 1981 account, "The First Bug," is now the standard reference on the whole affair.
The logbook is at the Smithsonian's National Museum of American History, and the moth photographs still turn up whenever you search for the term. Nearly eighty years on, computing's favorite metaphor remains a dead insect taped to a page — and it's still the best one.
https://americanhistory.si.edu/collections/object/nmah_334663
https://www.computerhistory.org/tdih/september/9/
On September 9, 1947, a team working on the Harvard Mark II computer found a moth wedged between the contacts of a relay, and the machine had stopped. They pulled it out, taped the dead insect into the computer's logbook, and one of the team wrote the most famous margin note in computing history: "First actual case of bug being found."
The twist: they didn't coin the word. Engineers had been calling small mechanical flaws "bugs" for decades before the first computers, and Thomas Edison was writing about bugs in electrical circuits in the 1870s. The Mark II incident didn't invent the term — it gave it a picture, a literal insect you could hold, which is why the story stuck.
One footnote, because it's true and it's kind. The logbook probably wasn't Grace Hopper's; it was the machine's log. But she was on that team in 1947, and she told this story so often and so well in her public lectures that the note is usually remembered as hers. Her 1981 account, "The First Bug," is now the standard reference on the whole affair.
The logbook is at the Smithsonian's National Museum of American History, and the moth photographs still turn up whenever you search for the term. Nearly eighty years on, computing's favorite metaphor remains a dead insect taped to a page — and it's still the best one.
https://americanhistory.si.edu/collections/object/nmah_334663
https://www.computerhistory.org/tdih/september/9/