This Roman chalice, the Lycurgus Cup, as it is known, began to give scientists sleepless nights when they noticed that it had a rather strange property. When lit from the front, this beautifully preserved cage cup appears to be a lovely shade of jade green, but when lit from behind, something spooky happens and it turns a startling shade of crimson. So, how did 4th Century romans manage to achieve this almost magical feat? It turns out that the glass is made from dichroic glass it is full of microscopic flecks of gold and silver so tiny that they can only be seen with an electron microscope. At this size, the flecks are a similar size to the wavelengths of visible light, causing an effect called Surface Plasmon Resonance (gesundheit), whereby the blue end of the spectrum is scattered, making it appear green, and the red end of the spectrum, with its longer wavelength, is transmitted through the glass, producing the back-lit red glow. So, in other words, the Romans got to nanotechnology a good 1,600 years before we did. Which is pretty embarrassing. However, due to the general lack of references to Nanus Technologus in classical texts, scientists suspect that, although they may have been able to reproduce it through trial and error, the Romans didnt know how or why the dichroic effect was being produced. It is likely that the glass was manufactured in a workshop which also produced gilded artefacts, and tiny fragments of gold and silver foil contaminated the glass. Either that or weve got some time-travelling Romans on our hands.
