CONCEPT
The Worker in the Boxes
Emil Post’s 1936 model of universal computation—a human being, idealized, moving through an infinite tape of marked and unmarked boxes, following a finite list of directions—the clearest proof that the most sophisticated AI behavior is composed entirely of operations as mindless as marking a box.
In 1936,
Emil Post published a three-page paper that defined the universal computing machine not as a mechanism but as a person. He described a worker—a human being, idealized to the point of pure obedience—moving through an infinite sequence of boxes, each of which can be empty or contain a single mark. The worker follows a finite list of directions: move one box left or right; mark an empty box or erase a marked one; observe whether the current box is marked and branch accordingly. That is the complete apparatus. Post’s claim—his version of what we now call the Church-Turing thesis—was that this stripped-down clerk, following a fixed finite set of directions over an unbounded tape of boxes, can carry out any process that deserves to be called computation. At the same moment and independently, Alan Turing had arrived at the same claim with a different model. The