An essay on 'thickness' explains why AI slop cannot survive the test of time

In an essay published by Experimental History on 18 August, the writer Adam Mastroianni revisits what makes a work of art worth returning to, and argues that the answer is something he calls thickness. Great works, he writes, unfurl in response to your attention: the more time you spend with them, the more you get out of them. The difficulty is that rewarding the careful reader usually means repelling the casual one.

Learning it from one painting

Mastroianni says he spent years treating museums like celebrity scavenger hunts until he got stuck in front of Hieronymus Bosch's The Garden of Earthly Delights, a triptych from five centuries ago that he describes as looking like a painting from five hundred years in the future. On one panel, a naked figure has music written on his backside while a companion points at it. In 2014 a student, Amelia Hamrick, transcribed and recorded that fragment and drew worldwide attention. Mastroianni later found blog posts by Ian Pittman, a specialist in medieval music, showing that Hamrick was not the first to resurrect the melody — and that the notation is not music at all: it has no clef, the notes are spaced at random and one staff carries the wrong number of lines. Turning it into a coherent song means inventing what is not there, or as Mastroianni puts it, hallucinating — the word we use when a language model does it. In Bosch's painting the unplayable notation is not a hidden Easter egg but a warning about secular music.

Four ingredients of thickness

The essay lists four thickening agents. First, roads not taken: thick art carries the traces of approaches tried and abandoned, as in Hokusai's four versions of the same idea, made at 33, 44, 46 and 72. Second, leaving an ingredient out: Betty Crocker deliberately keeps egg powder out of its cake mix so that bakers feel they are baking, and thick art likewise leaves room for something the audience brings. Third, reasons: ears recur throughout Hamlet, and that depth can be felt even by readers who never name it. Fourth, blood sacrifice — the visible cost of a life spent working, as in the carved altarpieces at the Met Cloisters, or Penn and Teller's fire-eating, which is no trick and shortens the performer's life.

The opposite of thickness

The piece then turns to slop. Bike mechanics joke about bicycle-shaped objects; Mastroianni extends the term to movie-shaped, book-shaped and thought-shaped ones. Slop holds no secrets and evaporates under scrutiny, which is why he is unsurprised that studies find people preferring AI art: the real question is what will still be watched decades from now. Longevity is why we read old books — we no longer brew Bronze Age beer, but we still tell Bronze Age stories. Startup pitches offering to automate his writing get a blunter verdict: ideas are not finished before the words are. They have to be thickened.