Airport body scanners–especially the newer full-body scanners–can be unnerving. Sure, they ostensibly protect us from other passengers, but they also expose us to unnecessary radiation, no matter how slight. But that doesn’t mean the technology can’t be used for good. Researchers announced at this year’s National Meeting & Exposition of the American Chemical Society that they have figured out how to use terahertz technology, used in everything from airport whole-body scanners to pharmaceutical industry quality control, to find hidden images located beneath frescoes (paintings done on a wall after fresh plaster has been added).
Scientists have all sorts of techniques at their disposal to evaluate art–in paintings, for example they use a variety of X-ray techniques (neutron, infrared, etc.) to find hidden art. But the use of terahertz spectroscopy, which involves beaming weak electromagnetic radiation at art, is fairly new.
The researchers presenting at the ACS meeting spent hours using terahertz technology to examine Trois hommes armés de lances, a 19th-century fresco that lives in the Louvre. They suspected that other art lay below the surface–a common occurrence with frescos, which were often redone after fading or if new owners wanted different art on their wall. And they were right–an entirely different Roman fresco is under the current one.
“We were amazed, and we were delighted,” said J. Bianca Jackson, one of the researchers behind the study. “We could not believe our eyes as the image materialized on the screen. Underneath the top painting of the folds of a man’s tunic, we saw an eye, a nose and then a mouth appear. We were seeing what likely was part of an ancient Roman fresco, thousands of years old.”
No word on who the mystery man is. That’s a puzzle for others to figure out. The researchers are already using the terahertz technique to study different works of art.