This is what thought looks like.

Ideas, and ideas about ideas. Suppositions and suspicions about relationships among abstract notions — shape, number, geometry, space — emerging through a fog of chalk dust, preferably of the silky Hagoromo chalk, originally from Japan, now made in South Korea.

In these diagrams, mysteries are being born and solved.

For the last year, Jessica Wynne, a photographer and professor at the Fashion Institute of Technology in New York, has been photographing mathematicians’ blackboards, finding art in the swirling gangs of symbols sketched in the heat of imagination, argument and speculation. “Do Not Erase,” a collection of these images, will be published by Princeton University Press in the fall of 2020.

“A mathematician, like a painter or poet, is a maker of patterns,” the British mathematician G.H. Hardy wrote in 1940. Ms. Wynne was drawn to math through her summer neighbors on Cape Cod, Amie Wilkinson and Benson Farb, who both teach at the University of Chicago. She began photographing their blackboards and felt an artistic kinship.