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The First Computer Bug

By Christine M. Kreiser
10/4/2017 • American History Magazine

One week after Americans celebrated the end of World War II, the massive Mark II computer that ran ordnance calculations for the U.S. Navy shut down. On September 9, 1945, at 1545 hours, technicians found the culprit: a moth trapped between two of the machine’s thousands of relay points. Navy personnel assigned to the Bureau of Ordnance Computation Project at Harvard University preserved the insect in the daily log, noting that it was “the first actual case of a bug being found” in a computer. The term “bug” had been used to describe a mechanical malfunction since Thomas Edison’s day. Now “computer bug” and “debugging” entered the tech lexicon. The debugging solution for the Harvard programmers was simple: Close the windows in the computer lab. Future debugging procedures would be more complicated. In 1949 mathematician John von Neumann theorized that constructing self-replicating computer programs was possible. Six decades later, bugs, worms, viruses and a host of other self-replicating intruders, collectively called malware, have become the bane of every computer user. Computer security experts estimate that 55,000 new malware programs are launched over the Internet every day.


Originally published in the February 2011 issue of American History. To subscribe, click here

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