‘It’s magic’: scientists rediscover how to make ancient Roman colour-changing glass

Scientists have rediscovered the ancient Roman technique for creating color-changing glass, exemplified by the 1,600-year-old Lycurgus Cup housed in the British Museum. This masterpiece of optical engineering has long baffled experts because it exhibits a jade green color under normal lighting, yet transforms to a ruby red when light is shone from behind. The ability of the Romans to achieve such a sophisticated effect in glass-making has been a mystery for centuries, showcasing their advanced proficiency in the craft. This rediscovery is significant because it unravels a long-standing historical and scientific enigma, potentially opening doors for modern applications in optical engineering and material science, while also deepening our understanding of ancient technologies. The 'magic' refers to the sophisticated optical properties that allow the glass to interact with light in such a dynamic way, a feat that contemporary scientists are now able to reproduce.