Posted on June 25, 2021 in History, humor, Innovation

First Computer ‘Bug’

Behold, a common moth. It died stuck in the newest Harvard Mark II after being caught in a relay. But there’s some misconception over whether or not this is why errors are called ‘bugs’, and the rest of the story’s sometimes forgotten. Here’s a brief overview – there’s links at the end for more information on each section, if you’d like to know more!


Source of the Term


The terms ‘bug’ and ‘debugging’ were already in use in regards to computers and similar machines. This moth incident wasn’t the origin of the term, but it’s a funny side note that an actual, literal bug got into the machine. It would be like actually ‘dropping the ball’ during a game.

The term ‘bug’ has been in use for machines since Edison, comes from Welsh, and used to mean irritating or vexing things. Over time, machinery problems got pretty freaking annoying, and insects, spiders, and other ‘bug’ family members bit and stung people. As English formed, the word was incorporated into general use, until it eventually came to mean three things to English speakers: little crawly things, computer problems, and something being persistent and annoying.

Bugbears, someone bugging you, something being buggy, etc. all come from this!


Grace Hopper


Grace graduated from Yale with her doctorate in math between wars, and worked as a professor before taking a leave of absence to try and get sworn in (several times) for the Navy. She’d been slightly too old, and then she was too thin, and then she was too useful to let go to war – eventually, she got in via persistence, and the military was lucky to have her.

She’d go on to help create UNIVAC as well as the Harvard math machines. Mark I was used towards the atomic bomb. She’d also continue to write and research in peacetime – COBOL, a programming language still used today (albeit rarely) was her creation, making computer language easier to read and write. She’d write papers the entire time she worked under the Navy, constantly pushing forward and improving the tech she worked on.

She was retired out of the Navy at 60, and then called back – and then she retired again, and then she got called back – she never really “retired”, as even when she left the service she was scouted by the private sector. Most of her roles in this time were advisory, and she helped guide tech companies in the right direction.


Harvard Math Machine


Harvard’s computer department is where Grace did some of her most memorable work! She’d helped assemble, program, and test these absolute behemoth machines. Harvard MK II is where the bug came in, but given the nature of the system, it’s safe to say her contributions in programming made it into all four machines. They built off of each other, each machine containing the best parts of the ones before it.

Anyway, Grace was crucial to testing, re-testing, re-retesting… and making improvements! Under Grace and a man named Howard Aiken, the department built and programmed the Harvard Mark II, a beast of a machine weighing well over 20 tons, taught to think with relay switches, magnetic tapes, and vacuum tubes. Besides the obvious talent in math, she was a pretty decent speaker, too! The duty of explaining the system usually fell to her, and she’d have to do so in a way the upper management would understand.

This wasn’t the only Harvard machine, either. They got to Mark VI before another computer-tech leap was made that moved Harvard University beyond the gigantic fridge-walls they’d been using. In short: Grace and the rest of the Harvard team were at the very forefront of new tech at the time, and usually either on the cutting edge or barely behind it.


Bug Time


Relay technology was new, and everybody who could get their hands on it was eager to see just what it could do. The Harvard Mark II was very fast, thanks in part to the relays that replaced the mechanical counters used in the Mark I. The downside to those relays is that they require a space between the contact points to work. When the space was open, no signal was sent (there was an air gap between the two parts), and when the space was closed, the signal could make it across. Relays are very fast, much faster than the counters previously used, and are still used today in things like light switches and car signals.

The moth got into the gap, closed the bridge, and allowed signals to be sent continuously, which ruined the machine’s results. Luckily, the machine was advanced enough to put up an error message instead of just shutting down or giving an incorrect answer, which would have been significantly more difficult to track down.

It’s a funny coincidence. A moment in time, caught in the relay of the world’s fastest computer. What a way to go. Good for you, moth. Good for you.



For more on the bug (with pictures):

For more on the definition of bug:–debugging-the-origins-of–bug-.html (Warning: this website would like you to sign up for their newsletter via pop-up)

For more on Rear Admiral Grace Hopper:

For more on the Harvard MK II