The double helix (1953)

Two sugar-phosphate backbones running antiparallel, wound about a common axis, crossing at every half-turn; roughly ten base pairs per turn. Published by Watson and Crick in April 1953, built on Franklin's and Gosling's Photo 51 and Wilkins' work, and it made heredity a copying problem overnight — unzip the two strands, and each is a template for its partner.

A date-line, so the shelf is honest: the serpent motif is c. 2100 BCE and older. The helix is 1953. Anything that identifies the one as the other is therefore, necessarily, later than 1953 — that is not a scientific judgement, it is arithmetic, and it is the same kind of statement this app makes when it says Mathers worked from Knorr's Latin of 1677. What the resemblance means is left to you. The room offers three readings and adjudicates none of them.