baccanalia (13. 916)

After centuries of study and several attempts to understand and recreate the colour-changing effect, a team from the University of Sheffield—an area instrumental to the Industrial Revolution, many technologies emerging from there including large scale stainless steel and commercial glass manufacture—have rediscovered the sixteen hundred year old methods that went into dichromatic the Lycurgus Cup (see previously here and here). The caged-chalice (diatretum) was made in Alexandria in the fourth-century of unknown provenance before the 1800s depicts a scene of the mythological Thracian king Lycurgus (Tamer of Wolves) who banned the cult of Dionysus (Bacchus to the Romans) in his home territory and punished the followers of the god of wine, and in the iconography on the cup, Ambrosia, Dionysus’ human nursemaid, is shown acting in self-defence, transformed into a powerful vine as she is being pursued by the enraged despot, whereupon entangling him, rending his wardrobe (a act called sparagmos (σπαραγμός) and strangling him to death. Embedded flakes of silver and gold (molten nano-crystals forming a lattice work in the glass invisible to the naked eye) shift the absorption and scattering of photons depending on whether the artefact is backlit or viewed in ambient light. Our favourite part of the interview was how one of the scientists imagined how Roman craftspeople would be bemused and incredulous on the effort and experimentation that went into recreating the effect, “‘Why does she not know how to make this?’” The new cup, a local glass artist commissioned to make it, will be unveiled to the public next month at the university.