Naglaa Walker came to photography by an unusual route. Before taking an MA in Fine Art Photography at the Royal College of Art, she trained as a scientist and worked for a time as a physics researcher. That biography is not incidental to *On Physics*, the book Dewi Lewis Publishing issued in 2004; it is the mechanism of the work. Across its pages, Walker builds diptychs that place blackboard images of chalked equations beside carefully staged photographs. The pairing does not illustrate the mathematics so much as hold it in tension with the visible world, inviting the viewer to trace how abstraction and lived experience might touch.

The book carries essays by two writers whose presence clarifies its ambitions. John Gribbin, the award-winning popular-science author, writes on the way scientific thought borrows imagery from ordinary life to make complex ideas legible. Sacha Craddock, an art critic, writer and curator, supplies a context in which Walker’s photographs might be considered and evaluated. Together they frame the project as a convergence of art and science rather than a one-way translation from one discipline into another. The volume comprises 144 pages and 64 colour photographs, in hardback, with dimensions of 297 by 210 millimetres.

For a collector, the interest lies less in rarity than in the work’s position: a photographer using the apparatus of scientific demonstration as a visual grammar, and doing so at the moment when her career was gaining recognition. The diptych structure gives the book a consistent rhythm, while the essays give the pictures an argument. It is a considered object from a publisher with a long commitment to photographic books and a document of an artist thinking seriously about how the abstract and the concrete can share a page.