Radioactive Artifacts

How do museums deal with radioactive artifacts? The question first popped in to my head when I was standing at the entrance of the Mütter Museum in Philadelphia, looking at a device built by Pierre Curie in the 1880s to measure radioactivity. Given that the device—a piezoelectric quartz electrometer—had spent decades measuring radioactivity, I guessed it probably was or had been radioactive itself. Then it occured to me that the devices used by Pierre and Marie Curie aren't the only kind of radioactive artifacts found in museum collections. German chemist Martin Heinrich Klaproth discovered uranium in 1789, and by 1830 the radioactive element was being used heavily as a yellow-green colorant in all sorts of glassware (before people even knew what radioactivity was). By the early 20th century, uranium oxide was used to color the incredibly popular orange-red ceramic Fiesta tableware favored by Andy Warhol and many others. And radium-226 was used to paint watches, aircraft gauges, door knobs, religious icons, light switches and even chamber pots so that they glowed in the dark. Radioactivity also became a health fad. Look no further than the “Lifetime Radium-Vitalizer Water Jar,” from the 1920s, which added radiation to water by means of a chunk of uranium ore at the bottom of the vessel. In addition to quack health products, radioactive artifacts are sometimes natural history museum minerals as well as relics and equipment from the Manhattan project and all subsequent nuclear testing. Since we are all exposed to low-levels of radiation daily--heck, our own bones emit radiation to those around us--the issue is whether a particular artifact emits enough radiation to present a health hazard to museum staff and the public. “Whenever a new artifact comes into the museum, the first thing I do is run a Geiger counter over it,” said Anna Dhody, the Mütter Museum’s curator, when I called to ask about Pierre Curie’s electrometer. You often don’t know the precise life trajectory of an artifact, she explained, and it’s wise to be precautious, particularly with donations. Pierre Curie’s electrometer had been professionally decontaminated by a nuclear physicist, Dhody said, but she couldn’t provide more details because it had happened before her tenure at the museum. She suggested I call up the National Atomic Testing Museum (NATM), whose whole modus operandi is to deal with artifacts related to the more than 1000 nuclear tests that took place from 1951 onwards at the Nevada Test Site, about 68 miles outside Las Vegas. “You don’t want to fool around with radioactive artifacts,” Karen Green, the NATM’s curator told me. She told me that the artifacts in the NATM, such as radiation...

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Using A Digital Light Projector To Restore Mark Rothko Paintings

One of the coolest talks I saw at the ICOM-CC conference in Lisbon last week came from Jens Stenger, a conservation scientist at the Harvard Art Museums in Boston. He had the tricky task of figuring out what to do about five paintings by Mark Rothko in the museum’s collection that were so damaged from sunlight exposure that crimson paint on the canvas had turned to blue. If just a tiny corner of the paintings were light damaged, museum staff might have considered retouching the artwork with a little paint. But a massive fraction of the massive panels were seriously light-damaged. And these days the trend in art conservation is to minimize interventions on art, especially contemporary art. So a team of curators, conservators and scientists decided that, “repainting was NOT the way to go,” Stenger said. But everyone thought museum visitors would want to know how the artwork had looked before the light damage. So what to do? The solution Stenger came up with is pretty cool: Figure out the exact coloration of the originals. Display the artwork as is, but set up a digital light projector that can cast an image on to the canvases. This projected image temporarily makes the paintings appear as they did when Rothko finished them in 1963. Switch off the projector and the paintings are returned to their current-day states. It’s effectively restoration with an undo button. (And as an aside, the amount of light delivered by the projector is not sufficient to continue to harm the painting.) But like most things in life, this seemingly simple solution took a lot of work. First off, Stenger wanted to know more about why the paintings had faded so dramatically. In 1988 Paul Whitmore reported that the fading crimson red paint in the Rothko paintings had been a synthetic pigment called Lithol red mixed in with a bit of ultramarine blue. Lithol red is a problematic pigment to begin with, Stenger said, but the fading due to the excessive sunlight exposure was probably exacerbated by the fact that Rothko mixed the red with ultramarine blue. It turns out ultramarine blue can also catalyze bleaching of Lithol red. Next up, Stenger looked for photographs of the original paintings, so that the team knew exactly the colors in the painting before fading. This way they could project the right color of light on to the old canvases. Luckily, color film ektachrome images of the Rothko canvases had been taken in 1963, Stenger said. The bad news is that some of the blue pigments in the ektachromes had faded, distorting the colors in the ektachrome image so...

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Jackson Pollock Physics

When Jackson Pollock made his art, he'd lie a canvas on the floor. Then he'd use a stick or trowel to drip, splatter or coil the paint on the canvas. Some critics thought Pollock's quirky, controversial style made the paintings look like a mop of tangled hair. Others have dropped millions of dollars to buy Pollock's work, calling him the best American artist of the 20th century. Perhaps it was Pollock's reliance on gravity and paint viscosity, but his style has also drawn the attention of physicists, whose theories about his work have ignited some controversy of their own. More on that in a moment. But first, the newest scientific take on Pollock: Physics Today recently described research by Harvard physicist L. Mahadevan and colleagues who used fluid physics to study Pollock's style. The researchers wanted to understand how Pollock employed gravity and paint of varying viscosities to make coils, splashes and spots on the canvas. Among other things, Mahadevan's team "demonstrated mathematically that the only way Pollock could create such tiny looping, meandering oscillations was to hold his brush or trowel high up off the canvas and let out a flow of paint that narrowed and sped up as it fell. To create tiny loops rather than waves, he likely moved his hand slowly, allowing physics to coauthor his art." What's interesting to me is that the fluid physics used to study Pollock's art was only developed after Pollock was already finished making his masterpieces. Pollock started doing his trademark paintings in the 1940s. Physicists started working out fluid dynamics in the 1950s and 60s. In other words, Pollock's use of fluid dynamics to make art predates the ability of physicists to mathematically model the same processes. Pollock was ahead of his time in more ways than one. Here's another case: Just over a decade ago, art historian and physicist Richard Taylor reported that there are fractals in Pollock's work. The term fractal was coined in 1975 by Benoît Mandelbrot--long after Pollock died in an alcohol-related car crash in 1956. And it's Taylor's work on Pollock fractals that has triggered some controversy of its own. Back in 1999, Nature magazine published an article by Taylor reporting how he had applied the rules of fractal geometry to Pollock paintings and found that his artwork had fractal dimensions similar to that of natural contours such as those found in trees, clouds or a coastline. In other words, the aesthetic appeal of Pollock's paintings is that they make you feel like you are on a beach. Lots of media outlets such as Discover and Scientific American hopped on the story. With...

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