Systematic chemical nomenclature is an exercise in compression. Two-dimensional molecular diagrams are the “iconic vernacular” of chemistry (writes chemist-essayist Roald Hoffmann). Rules for systematic naming and notation are a mechanism for compressing *lots and lots* of two-dimensional molecular diagrams into one-dimensional strings. Unlike the diagrams, these strings can be efficiently written, ordered, and located in very, very long lists. … More Evan Hepler-Smith (Harvard), “Transition States: Compressing Molecules across Time and Media”