By David Gura
When I was an undergraduate, I often walked by the entrance to the Cornell High Energy Synchrotron Source (CHESS), a portal to Cornell University's subterranean sub-atomic particle accelerator.
I had no idea what happened down there, beneath the varsity soccer field. Did they use it for good? For evil? For entertainment? (In a library on campus, there was a photograph of a grinning Hans Bethe, the Nobel Prize-winning physicist, pedaling a bike through one of the synchrotron's long tunnels.)
As a history major, I never found out.
Today, I learned that, among other things, a synchrotron can help art conservationists. Using the particle accelerator, scientists peeled away layers of paint on an N.C. Wyeth painting, "Family Portrait," to reveal a colorful first draft of another Wyeth work:
Their device focuses an X-ray beam onto a painting and collects the fluorescent X-rays given off by the chemicals in the various layers of paint. Each color of paint produces a unique fluorescence spectrum, like a chemical fingerprint, which can then be mapped to reconstruct the original color schemes in the hidden painting.