A team of researchers has successfully replicated a 1,600-year-old Roman glass goblet that changes color depending on the angle of light. The Lycurgus Cup, named after the king of the Thracians in Homer's Iliad, is a masterpiece of ancient Roman glassmaking. The cup's unique property is due to the presence of nanoparticles of gold and silver embedded in the glass, which distort incoming light. This technique, known as dichroic glass, was previously thought to be a product of modern technology. However, researchers at the University of Sheffield have demonstrated that the ancient Romans were able to achieve this effect using 4th-century CE tools and materials. The team, led by glass technical specialist Lisa Hollands, used a combination of experimentation and trial-and-error to recreate the glass. They found that the color of the glass was highly dependent on its position within the furnace, making it a challenging process to control. The replicated glass was then passed on to glass artist Elliot Walker, who created a new piece that pays homage to the Lycurgus Cup and a famous sculpture of Atlas carrying the world on his back. The new piece will be exhibited permanently at the University of Sheffield's Turner Museum of Glass. This achievement is a testament to the ingenuity and skill of the ancient Romans, who were able to push the boundaries of what was thought possible with their materials and techniques.