Edgar Degas is a beloved 19th-century impressionist painter from France. But one of his paintings, Portrait of a Woman, doesn’t look so great. As the oil paint has faded over the decades, a dark cloud has appeared on the woman’s face. It’s the shadow of an earlier painting that Degas covered up. Finally, we can see what the hidden painting looks like.
Researchers brought Portrait of a Woman to a particle accelerator called a synchrotron. The device generates a narrow, intense X-ray beam. The team used this beam to scan the artwork and map out the chemical elements in the hidden painting. Knowing those elements allowed them to guess what paint colors are hiding on each part of the canvas. Zinc probably came from white paint, for example. Mercury was…
