Gold’s gleam has fascinated humans for millennia. Giuseppe Strangi, professor of physics at Case Western Reserve University, wants to use gold’s special relationship with light in the fight against cancer. It started centuries ago, when people melted gold into stained glass. Strangi describes the unexpected discovery. "If you go in France and look at the cathedrals, you see that this color is not coming from any pigment, but is coming from gold, coming from the fact that gold is absorbing light