Christopher Strachey’s Love-Letter-Writing Machine

Nephew of one of the Bloomsbury group's founders, Lytton Strachey, Christopher Strachey was a programmer in the University of Manchester computer lab when, in August of 1953, he wrote a program to generate "overwrought love letters" from the Manchester University computer. No two appeared the same, due to Strachey's thoughtful use of Roget’s Thesaurus for a richly various vocabulary. Each one was based on the same syntactic template, as New Yorker's Siobhan Roberts explains: "Dripping with lustful vocabulary, they were all variations on a basic syntactic template: 'YOU ARE MY [adjective] [noun]. MY [adjective] [noun] [adverb] [verbs] YOUR [adjective] [noun].' And the signatory was always the same: 'M.U.C.,' for the Manchester University computer, a Ferranti Mark 1, the world’s first general-purpose and commercially available machine of its kind." More:

But the real author of the letters (in the first instance, anyway) was Christopher Strachey, a pioneering programmer. As he confessed in an article the following year, "There are many obvious imperfections in this scheme (indeed very little thought went into its devising), and the fact that the vocabulary was largely based on Roget’s Thesaurus lends a very peculiar flavor to the results." For Strachey, though, the interesting thing was how a simple setup, using only about seventy base words, could produce a combinatorial explosion of results—on the order of three hundred billion different letters. The lovelorn user could run the program over and over until his fingers seized up, and never see the same letter twice.

Strachey was something of an outlier, according to Martin Campbell-Kelly, a historian of computing at the University of Warwick. While scientists and mathematicians of the day typically used computers strictly for numerical calculations, like analyzing weapons trajectories or seeking prime factors of huge numbers, his fascination was with non-numerical computations—what soon became known as artificial intelligence. "Strachey grabbed hold of that much more than anybody else," Campbell-Kelly told me. The results were not always lovey-dovey. Besides training the Mark 1 to churn out billets-doux, he also taught it to play checkers ("draughts," in British parlance). If M.U.C.’s opponent made too many mistakes, it would get crotchety and print out a reprimand: "I refuse to waste any more time. Go and play with a human being."

Continue exploring (and generate a few love-letters of your own) at The New Yorker.