One snowy afternoon in December, several women gathered in artist Mary Simon-Casati's southwest Minneapolis home for a little lunch and a lightweight chat about astrophysics and art. The firelit living room crackled with energy; conversation sparked and flared, bouncing from philosopher to art historian to physicist and back, traversing the cosmic terrain of dark matter, energy, quarks and their quasi-poetic names.

"The thing about particles," the artist said offhandedly, "is that none of us can see them, ever. We don't know what they look like. Science can figure out what sort of spin they have and what it interacts with. But otherwise, we're dealing with the unknown."

Her latest paintings and sculpture explore, in visual terms, phenomena that are largely intangible, ineffable and unseen. The result of three years of research and an intensive yearlong exchange of ideas with University of Minnesota astrophysicist Liliya Williams, her solo show "Smashing the Invisible" is on view at the university's Regis Center for Art through Feb. 10.

Simon-Casati's lifelong fascination with the unknown was brought into sharp focus when her mother passed away. Grappling with the enormity of absence and loss, she began to wonder: What happens to matter after we die? Where does energy go? "I liked the idea that we become stars, because we come from stars," she laughs. "That's not quite the case."

Her questions unfolded into further questions, leading her eventually to Williams' work, which maps the location of dark matter in space.

As their intellectual conversation evolved into friendship, Williams and Simon-Casati sought a common lexicon with which to describe their disparate visions of the world. In the process, they found a few fundamental concepts — symmetry, clarity, ambiguity, objectivity and subjectivity, the abstract and the concrete — that underlie and inform their understanding of reality itself.

"What physics strives for is clarity in the perception of the world," Williams says. "In art, it's the other way around — you want the viewer to read whatever makes sense to them into that particular piece of art. Your eyes perceive the painting itself, but what that means for you and what you get out of it goes beyond that painting."

'A beautiful question'

The historical relationship between scientific inquiry and visual art predates even Leonardo da Vinci, though his artistic renderings of scientific subjects are perhaps the best-known example of this overlap.

Our most basic understanding of the natural world is derived in part from the sketches and drawings — the art — of early scientists, naturalists and physicians. Until the invention of things like the microscope, the photograph and the computer, scientists had no tools other than art with which to present their discoveries in visual form. Similarly, Simon-Casati points out, "Artists have always used close observation and research to help them understand how things work."

But there are other commonalities, as well. Both science and visual art require an extraordinary level of focus and precision in their observation of the world. Both are fundamentally experimental in nature. And although science holds fast to the notion that there is an objective reality that can be located and named, while art cleaves with equal fidelity to the belief that subjective reality is a more accurate and more interesting way of looking at the world, scientists and artists alike are faced with the problem of representing reality in some new, unprecedented way.

"So when Liliya shows me a 'map' of where they think dark matter is, I am instantly fascinated," says Simon-Casati, whose project was supported by a State Arts Board grant. "The practical question for me was: How do I interpret this? How can I make something that addresses an entity like dark matter, when no one knows what it is? How can I imagine it materially, spatially? How can I communicate the bigness of this stuff that exists in the universe but is invisible? Essential but invisible!

"When I started making the paintings, I did it almost like I was blindfolded, to let my hands understand something that is invisible but essential. I felt that idea intuitively."

Starting from nowhere

Simon-Casati was born and raised in rural South Dakota.

"One of the biggest influences on me was growing up on the prairie, out on that farm in the middle of nowhere," she says. "There are times and places out there that you can almost see the curvature of the Earth. And then there's the constant wind. I found that fascinating as a girl, the movement. And you do feel a certain disorientation when you go out there — you're in the middle of all this wind and the grasses are moving and the colors are moving and it's undulating, like the ocean. I loved that. I found it oddly comforting.

"When I was a really little kid, my mom brought me a coloring book. I was all over the place with it. And she goes, 'No. That's not the way you do it.' It was a peach hanging on a stem of a branch. And she showed me how to blend orange and yellow to make a peach color. And I was like, 'Whoa. This is pretty cool.' "

When her mother died, "I didn't know what was going to happen," she says. "I just went to the art store and got paper and took a brush and ink and made all these marks. I probably made 200, 300 of them. At one point, my mentor and I had them all over the living room and the dining room and on the table. And I could see that this was a language, a visual language.

"That's why you make art," she says. "Because there aren't words. There are no words for grief, not really. There are no words for how much I miss my mother. Even now, today, how much I miss her, and how pissed I am that she's gone because she can't be at the show."

These large-scale works — most of them acrylic and mixed media on aluminum — are Simon-Casati's interpretation of some of the most central ideas in physics. Her gestural brushwork, executed using everything from feather dusters to massive horsehair brushes that she made herself, gives the viewer a sweeping sense of motion, gradation, dimension and depth. Titles like "Complementarity," "Turbulence," "Broken Symmetry" and "Transformation" suggest both theoretical and metaphorical interpretations; the viewer experiences the works as a vertiginous encounter with space.

"The whole idea of making an equation and making a work of art are very similar," she says. "I think that underneath how Liliya [Williams] represents the world, and how I represent the world, there is a beautiful question. If a work of art or an equation elicits in you a question, even if there's no answer for it, I think that is what you strive for — a question like, 'Well, how does that work?' "

The creative leap

"There are many things we don't know about dark matter," Williams says a few days later, perched at her desk in her U office like an especially alert bird. "We do know some things. Or, equivalently, certain classes of hypothesis have been ruled out. We know dark matter has to be a particle. Some would propose that it's a modification of laws of physics, but no. We're pretty darn sure that it is actually stuff.

"What I'm doing is quite exact, in the sense that there's a physical problem and we're trying to solve it. And for this problem, there is an answer. But when you embark on a specific question within research, the answer can be profound. It can be trivial. It can be reachable. It can be 100 years beyond your reach. All of those possibilities exist."

Science and art both require precise processes of thought, perhaps even a precise sort of mind, but it's not as simple as a left/right brain dichotomy. Williams says of scientific research, "Sometimes all the existing data and experiments are there, but it takes a leap of creativity to bring them together and make collective sense out of it. And that's the part that you want to say is magic. You really do go from one place, conceptually, to a different place, but how that 'a-ha' moment occurs, I don't know."

She and Simon-Casati use strikingly similar language to describe their creative process, echoing and even quoting each other on the subject. "Liliya says that creativity depends on a prepared mind," Simon-Casati says, pointing out that this holds true whether you're working on canvas or code — and in either case, you get stuck.

"Oh, there are the little stucknesses that you experience more than once a day," Williams says. "Then there are stucknesses that persist for a week or a month, and there are others that persist for years. The little ones, the local ones — you just need to stare at it and you'll figure it out eventually. The bigger ones, there's really no guarantee that there is even an answer. So for those, you have to be prepared. If it's there, then it will occur to you.

"Both science and art are human endeavors," Williams adds. "In both cases, I think it is about a search for beauty."

Simon-Casati agrees, saying, "In physics, you can express this huge idea in a single equation. And a great artist can show you the beauty and the horror in the same piece. You have to look for it and it's very subtle, but you see it. And I find that very interesting, and necessary. Human beings need to see beauty, and they need to see behind that beauty."

Marya Hornbacher is an award-winning science and arts journalist and the bestselling author of five books.