We have a few terms in English that describe an amount of work in units of people. For example, we used to talk about a man-hour to refer to the amount of work that one person can do in an hour. These days we’re not as comfortable using the word man as an umbrella term—a hypernym—for people, and we’ll use a more inclusive term like person-hour.
But in earlier times we had a number of these units-per-person terms. There’s also the similarly man-based term manpower, which in the past was used to refer generically to people available to do something (“This job needs a lot of manpower”). I was a little surprised to learn that the word manpower also had (has?) a formal definition that referred to a specific quantity, analogous with horsepower. (One manpower is approximately 75 watts, which is about 1/12 of one horsepower.)
Not long ago I ran across another unit-of-work term like this. It was also sex-marked, but for women. But it requires a bit of history.
For most of human history, mathematical calculations were mostly done by hand. People did invent some shortcuts. There was the abacus (from Greek abax, meaning “counting board”), and people also devised ways to use a “mental abacus” using their hands to perform complex calculations, like the chisanbop method from Korea. Another shortcut, though we don’t generally think of it that way, was the adoption of the Hindu-Arabic base 10 number system. But math was mostly a matter of brain power and paper.
Bear with me, we’re getting there. You might know that the original sense of the word computer was “one who computes”—that is, someone who could perform calculations. For example, in 1704 Johnathan Swift referred to “A very skillful Computer, who hath given a full Demonstration of it from Rules of Arithmetick.”
As technology got more complicated, the calculations that were needed likewise became more complicated. To work out the math for things like planetary orbits, teams of computers (in the human sense) were organized to perform the calculations. In the 19th century, the teams started including women. During WWII, many women were hired as computers and worked on calculations for the Manhattan Project, and when the space program began after the war, women also worked on the complex math for rocket trajectories.[1]
And now to get back to the discussion of sex-marked terms. Women who worked as computers were sometimes referred to as computresses. (The linguist Anne Curzan has a great interview on the old Lexicon Valley podcast in which she discusses feminine endings like -ess.) Or to go even further, as David Alan Grier notes in his book When Computers Were Human, in the 1940s, women computers were also just referred to as girls.
Remember man-hours? Because the calculations that the, um, computresses worked on took a long time, people also started referring to girl-hours, as in, a problem would take the computers a certain number of hours to calculate. Particularly complex problems might take thousands of these “girl-hours.” Someone therefore came up with the light-hearted term kilogirls: the amount of calculations that 1000 women could do in an hour. (I assume it was light-hearted, anyway.) On Twitter, Ethan Mollick performed a conversion of teraflops, a contemporary measure of a computer’s speed, to kilogirls, and estimates that “The fastest computer today runs at 7 quintillion kilogirls.” In this latter-day reference to computer, of course, Mollick is referring to the mechanical computer that made human computers mostly obsolete.
As I said at the beginning, a term like man-hours now seems sexist to us, and we have moved to a term like person-hour. Where I work, we’ve gone to some effort at work to make sure that we don’t use terms that imply that man stands for “person” or “human,” and we list suggested replacements for terms like man-hours, man-in-the-middle, manmade, manned, and manpower.
From our perspective today, it’s hard to imagine referring to a group of adult colleagues as girls. Times were different then, of course. But though I can’t imagine using a term like that today, I appreciate the linguistic (mathematical?) inventiveness of a term like kilogirl.
Like this? Read all the Friday words.
__________
[1] The book and movie Hidden Figures recount the stories of some of these women. [^]