Jackson Pollock, famous for his deceptively random-seeming drip paintings, took advantage of certain features of fluid dynamics years before physicists thought to study them.

"His particular painting technique essentially lets physics be a player in the creative process," said physicist Andrzej Herczynski of Boston College, coauthor of a new paper in Physics Today that analyzes the physics in Pollock's art. "To the degree that he lets physics take a role in the painting process, he is inviting physics to be a coauthor of his pieces."

Pollock's unique technique – letting paint drip and splatter on the floor rather than spreading it on a vertical canvas – revolutionized the art world in the 1940s. The resulting streaks and blobs look haphazard, but art historians and, more recently, physicists argue they're anything but. Some have suggested that the snarls of paint have lasting appeal because they reflect fractal geometry that shows up in clouds and coast lines.

Now, Boston College art historian Claude Cernuschi, Harvard mathematician Lakshminarayanan Mahadevan and Herczynski have turned the tools of physics on Pollock's painting process. In what they believe is the first quantitative analysis of drip painting, the researchers derived an equation for how Pollock spread paint.

The team focused on the painting Untitled 1948-49, which features wiggling lines and curlicues of red paint. Those loops formed through a fluid instability called coiling, in which thick fluids fold onto themselves like coils of rope.

"People thought perhaps Pollock created this effect by wiggling his hand in a sinusoidal way, but he didn't," Herczynski said.

Coiling is familiar to anyone who's ever squeezed honey on toast, but it's only recently grabbed the attention of physicists. Recent studies have shown that the patterns fluids form as they fall depends on their viscosity and their speed. Viscous liquids fall in straight lines when moving quickly, but form loops, squiggles and figure eights when poured slowly, as seen in this video of honey falling on a conveyor belt.

The first physics papers that touched on this phenomenon appeared in the late 1950s, but Pollock knew all about it in 1948. Pollock was famous for searching for using different kinds of paints than anyone else in the art world, and mixing his paints with solvents to make them thicker or thinner. Instead of using a brush or pouring paint directly from a can, he lifted paint with a rod and let it dribble onto the canvas in continuous streams. By moving his arm at different speeds and using paints of different thicknesses, he could control how much coiling showed up in the final painting.

"When Pollock was doing that, when he mixed his paints and diluted them and chose paints of similar density and different viscosity and so on, in a way he was doing experiments in fluid dynamics," Herczynski said. "What's interesting here is that he set out, in this painting in particular, to explore that effect before physicists were exploring it."

Pollock probably didn't consciously realize how he was exploiting fluid dynamics in his paintings. "I think if you told Pollock, 'You're exploring physics,' he would think you were crazy," Herczynski said. "He did it intuitively. His interest was not so much the physics of the process, it was to achieve a certain aesthetic effect. But the two are bound together. You can't separate them. You're inviting physics to be a part of it."

Image: Flickr/Fiona and Graeme

Citation: "Painting with drops, jets and sheets." Andrzej Herczynski, Claude Cernuschi, and L. Mahadevan. Physics Today, Vol. 64, Issue 6. June 2011.

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