A Sunday Afternoon on the Island of La Grande Jatte is perhaps Georges Seurat’s most famous painting. A pioneering work of pointillism, millions of tiny dots resolving themselves into a pastoral scene of figures in a park through a trick of colour and light, A Sunday Afternoon hangs in the collection of the Art Institute of Chicago. In 1982 James Lapine and Stephen Sondheim paid it a visit and came up with one of their most celebrated musicals, Sunday in the Park with George. In 2022 my best friend paid it a visit and sent me a photo of herself posing with the figures yesterday.

Zinc chromate is a chemical compound with the formula ZnCrO₄. It is used industrially as a coating over iron or aluminium materials, synthesised in a process developed by the Ford Motor Company in the 1920s. It is also highly toxic and can cause cancer.

I never really bothered to wonder what A Sunday Afternoon on the Island of La Grande Jatte and zinc chromate had to do with each other. At least, I never did until to-day, when now my mind is consumed with thoughts of exactly that. One’s a pointillist painting, and one’s a chemical compound.

But on Wikipedia’s article for A Sunday Afternoon on the Island of La Grande Jatte, the Related Articles section at the bottom lists, in order: Georges Seurat, Zinc chromate, and Models (painting).

And on Wikipedia’s article for zinc chromate, the Related Articles section lists, in order: A Sunday Afternoon on the Island of La Grande Jatte, Chromate conversion coating, and List of inorganic pigments.

Okay. Does anybody else think that’s strange? I feel that A Sunday Afternoon on the Island of La Grande Jatte would inspire me to think of a thousand other things more related to it (like Sunday in the Park with George, for example) than zinc chromate. Why does zinc chromate claim the No. 2 spot in A Sunday Afternoon’s related articles?

And vice versa. Zinc chromate would inspire me to read about a thousand more chemicals and compounds and industrial processes before it could even suggest a dotty painting.

Is this possibly just a quirk of Wikipedia’s recommendation algorithm? Have the folks at Wikipedia been trying to use neural networks to recommend articles now?

Ah. Upon further reading, it looks like Seurat used zinc chromate as a yellow pigment in the painting of A Sunday Afternoon on the Island of La Grande Jatte. Fine.

I mean, this still doesn’t sate my confusion as to why zinc chromate is so prominent on the list of A Sunday Afternoon’s related articles. It still feels like you have dozens of best friends to choose from but somehow your bank teller ends up being one of your bridesmaids.