 advantage, specific to the hard X-ray nanoprobe, is that we can focus the X-rays on a pixel. In principle, we can distinguish between different oxidation states of iron, zinc, copper and so on. Synchrotron technology [using intense X-rays spit out by powerful, circular particle accelerators] opens up a totally new avenue for studying these materials.
It’s like a new way of looking at the same painting again.
Yes. It’s actually looking deeper, picking up information that was not accessible before. The technology used until now didn’t have the ability to study at this small scale.
What was it like to work with these paintings?
We didn’t study the whole painting. The Art Institute took the samples. We were interested in looking into one single pigment, so we didn’t need the whole painting—just a tiny sample, like the head of a pin. The pieces are almost like dust.
For a lot of our research, we make our own samples, hundreds or thousands if needed. So if something happens to them, it’s no big deal. For the Picasso sample (bright white pigments, left), the number was drastically reduced. We are also studying extremely precious samples in other areas. I had one researcher come to me to study one particle of stardust, 10 microns [0.01 millimeters] large.
But from a chemical perspective, we were just studying zinc white here, a piece of paint. Zinc oxide is something we study all the time for its potential as a display material in solar cells, or as a potential replacement for all the silicon electronics we currently use.
Is there something you can extrapolate from the painting to modern technology?
Yes, that’s an important point. People like you, people who pay taxes, might ask why a Department of Energy laboratory is studying Picasso's paint.
We learn something about zinc oxide that has applications in areas that are not cultural heritage at all. For example, the impurities in zinc oxide in this sample tell us how these might behave in advanced electronics.
A lot of physicists study zinc oxide as a so-called dilute semiconductor—in small magnets for memory in computers, for example. What they might not know is that they’re also studying Picasso paint at the same time. It’s the same material.
Your work helped settle a long-standing question about the kind of paint Picasso used. Do you think there are other controversies you might be able to resolve?
I think we can help support other kinds of research by art historians. We have to be careful, though. All the science we do will always be just one building block. We cannot expect to put a painting into a machine and out comes a paper that tells me who the artist was.
Has your perspective of art changed after you started these projects?
Absolutely. I have gained the ability to read a little bit more, so even with my eyes I try to look below the surface. I see paintings differently now. I ask myself more questions; I try to form a closer relationship to art.
What kinds of questions do you ask yourself?
That depends on the painting. As scientists we are trained to think and operate in a certain way. It would be wrong to say science can’t touch your feelings—like when you get a result after hundreds of hours of trying. I can get very emotional about science, in a good and bad sense. But in science, we want effects in terms of numbers and graphs. When you stand in front of a painting, that’s exactly what you don’t want. You don’t want to analyze. You want to receive it without filtering. This is about two different aspects of life.
"We cannot expect to put a painting into a machine and out comes a paper that tells me who the artist was."
Was there a particular moment during this work when your perspectives about art changed?
One of the first times I visited the Art Institute, I had an experience few other visitors get. I went to the back, where I saw a painting that was not in its frame. You could see the artist had scribbled on the back of the canvas. When I saw that, I felt much more connected and closer to the artist, as though I was standing next to him as he was painting and scri