What a 1973 archaeologist with one pencil figured out about your tech-debt backlog — and why teams keep trying to solve a graph problem by sorting a list.
One evening in February 1973, in Winchester, England, an archaeologist named Edward Cecil Harris sat down with the field notes of a 1960s excavation he could not make sense of. The site had generated the kind of record that was normal for its time: one-dimensional physical sections, profiles drawn on graph paper — depth of soil on the page, time flowing downward by assumption. Read the drawings carefully and the site still refused to resolve. Which wall was built before which floor? Which pit cut through which midden? He had the drawings. He could not get from the drawings to the story.
By morning he had invented the Harris Matrix.
What he did that evening was not fieldwork, and it was not a better drawing. It was a refusal — the refusal to let the answer live inside the two-dimensional profile at all. He threw away the section and drew, instead, a graph: one node per stratigraphic unit, one edge for every "this sits above that" contact, and only for the immediate contacts. Any wider ordering would emerge on its own. What looked like a drawing problem had always been a graph problem. No one before him had made the move.
